Mercurial > hg > CbC > CbC_gcc
comparison gcc/reload1.c @ 0:a06113de4d67
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author | kent <kent@cr.ie.u-ryukyu.ac.jp> |
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date | Fri, 17 Jul 2009 14:47:48 +0900 |
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children | 77e2b8dfacca |
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1 /* Reload pseudo regs into hard regs for insns that require hard regs. | |
2 Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998, | |
3 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 | |
4 Free Software Foundation, Inc. | |
5 | |
6 This file is part of GCC. | |
7 | |
8 GCC is free software; you can redistribute it and/or modify it under | |
9 the terms of the GNU General Public License as published by the Free | |
10 Software Foundation; either version 3, or (at your option) any later | |
11 version. | |
12 | |
13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY | |
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
16 for more details. | |
17 | |
18 You should have received a copy of the GNU General Public License | |
19 along with GCC; see the file COPYING3. If not see | |
20 <http://www.gnu.org/licenses/>. */ | |
21 | |
22 #include "config.h" | |
23 #include "system.h" | |
24 #include "coretypes.h" | |
25 #include "tm.h" | |
26 | |
27 #include "machmode.h" | |
28 #include "hard-reg-set.h" | |
29 #include "rtl.h" | |
30 #include "tm_p.h" | |
31 #include "obstack.h" | |
32 #include "insn-config.h" | |
33 #include "flags.h" | |
34 #include "function.h" | |
35 #include "expr.h" | |
36 #include "optabs.h" | |
37 #include "regs.h" | |
38 #include "addresses.h" | |
39 #include "basic-block.h" | |
40 #include "reload.h" | |
41 #include "recog.h" | |
42 #include "output.h" | |
43 #include "real.h" | |
44 #include "toplev.h" | |
45 #include "except.h" | |
46 #include "tree.h" | |
47 #include "ira.h" | |
48 #include "df.h" | |
49 #include "target.h" | |
50 #include "emit-rtl.h" | |
51 | |
52 /* This file contains the reload pass of the compiler, which is | |
53 run after register allocation has been done. It checks that | |
54 each insn is valid (operands required to be in registers really | |
55 are in registers of the proper class) and fixes up invalid ones | |
56 by copying values temporarily into registers for the insns | |
57 that need them. | |
58 | |
59 The results of register allocation are described by the vector | |
60 reg_renumber; the insns still contain pseudo regs, but reg_renumber | |
61 can be used to find which hard reg, if any, a pseudo reg is in. | |
62 | |
63 The technique we always use is to free up a few hard regs that are | |
64 called ``reload regs'', and for each place where a pseudo reg | |
65 must be in a hard reg, copy it temporarily into one of the reload regs. | |
66 | |
67 Reload regs are allocated locally for every instruction that needs | |
68 reloads. When there are pseudos which are allocated to a register that | |
69 has been chosen as a reload reg, such pseudos must be ``spilled''. | |
70 This means that they go to other hard regs, or to stack slots if no other | |
71 available hard regs can be found. Spilling can invalidate more | |
72 insns, requiring additional need for reloads, so we must keep checking | |
73 until the process stabilizes. | |
74 | |
75 For machines with different classes of registers, we must keep track | |
76 of the register class needed for each reload, and make sure that | |
77 we allocate enough reload registers of each class. | |
78 | |
79 The file reload.c contains the code that checks one insn for | |
80 validity and reports the reloads that it needs. This file | |
81 is in charge of scanning the entire rtl code, accumulating the | |
82 reload needs, spilling, assigning reload registers to use for | |
83 fixing up each insn, and generating the new insns to copy values | |
84 into the reload registers. */ | |
85 | |
86 /* During reload_as_needed, element N contains a REG rtx for the hard reg | |
87 into which reg N has been reloaded (perhaps for a previous insn). */ | |
88 static rtx *reg_last_reload_reg; | |
89 | |
90 /* Elt N nonzero if reg_last_reload_reg[N] has been set in this insn | |
91 for an output reload that stores into reg N. */ | |
92 static regset_head reg_has_output_reload; | |
93 | |
94 /* Indicates which hard regs are reload-registers for an output reload | |
95 in the current insn. */ | |
96 static HARD_REG_SET reg_is_output_reload; | |
97 | |
98 /* Element N is the constant value to which pseudo reg N is equivalent, | |
99 or zero if pseudo reg N is not equivalent to a constant. | |
100 find_reloads looks at this in order to replace pseudo reg N | |
101 with the constant it stands for. */ | |
102 rtx *reg_equiv_constant; | |
103 | |
104 /* Element N is an invariant value to which pseudo reg N is equivalent. | |
105 eliminate_regs_in_insn uses this to replace pseudos in particular | |
106 contexts. */ | |
107 rtx *reg_equiv_invariant; | |
108 | |
109 /* Element N is a memory location to which pseudo reg N is equivalent, | |
110 prior to any register elimination (such as frame pointer to stack | |
111 pointer). Depending on whether or not it is a valid address, this value | |
112 is transferred to either reg_equiv_address or reg_equiv_mem. */ | |
113 rtx *reg_equiv_memory_loc; | |
114 | |
115 /* We allocate reg_equiv_memory_loc inside a varray so that the garbage | |
116 collector can keep track of what is inside. */ | |
117 VEC(rtx,gc) *reg_equiv_memory_loc_vec; | |
118 | |
119 /* Element N is the address of stack slot to which pseudo reg N is equivalent. | |
120 This is used when the address is not valid as a memory address | |
121 (because its displacement is too big for the machine.) */ | |
122 rtx *reg_equiv_address; | |
123 | |
124 /* Element N is the memory slot to which pseudo reg N is equivalent, | |
125 or zero if pseudo reg N is not equivalent to a memory slot. */ | |
126 rtx *reg_equiv_mem; | |
127 | |
128 /* Element N is an EXPR_LIST of REG_EQUIVs containing MEMs with | |
129 alternate representations of the location of pseudo reg N. */ | |
130 rtx *reg_equiv_alt_mem_list; | |
131 | |
132 /* Widest width in which each pseudo reg is referred to (via subreg). */ | |
133 static unsigned int *reg_max_ref_width; | |
134 | |
135 /* Element N is the list of insns that initialized reg N from its equivalent | |
136 constant or memory slot. */ | |
137 rtx *reg_equiv_init; | |
138 int reg_equiv_init_size; | |
139 | |
140 /* Vector to remember old contents of reg_renumber before spilling. */ | |
141 static short *reg_old_renumber; | |
142 | |
143 /* During reload_as_needed, element N contains the last pseudo regno reloaded | |
144 into hard register N. If that pseudo reg occupied more than one register, | |
145 reg_reloaded_contents points to that pseudo for each spill register in | |
146 use; all of these must remain set for an inheritance to occur. */ | |
147 static int reg_reloaded_contents[FIRST_PSEUDO_REGISTER]; | |
148 | |
149 /* During reload_as_needed, element N contains the insn for which | |
150 hard register N was last used. Its contents are significant only | |
151 when reg_reloaded_valid is set for this register. */ | |
152 static rtx reg_reloaded_insn[FIRST_PSEUDO_REGISTER]; | |
153 | |
154 /* Indicate if reg_reloaded_insn / reg_reloaded_contents is valid. */ | |
155 static HARD_REG_SET reg_reloaded_valid; | |
156 /* Indicate if the register was dead at the end of the reload. | |
157 This is only valid if reg_reloaded_contents is set and valid. */ | |
158 static HARD_REG_SET reg_reloaded_dead; | |
159 | |
160 /* Indicate whether the register's current value is one that is not | |
161 safe to retain across a call, even for registers that are normally | |
162 call-saved. This is only meaningful for members of reg_reloaded_valid. */ | |
163 static HARD_REG_SET reg_reloaded_call_part_clobbered; | |
164 | |
165 /* Number of spill-regs so far; number of valid elements of spill_regs. */ | |
166 static int n_spills; | |
167 | |
168 /* In parallel with spill_regs, contains REG rtx's for those regs. | |
169 Holds the last rtx used for any given reg, or 0 if it has never | |
170 been used for spilling yet. This rtx is reused, provided it has | |
171 the proper mode. */ | |
172 static rtx spill_reg_rtx[FIRST_PSEUDO_REGISTER]; | |
173 | |
174 /* In parallel with spill_regs, contains nonzero for a spill reg | |
175 that was stored after the last time it was used. | |
176 The precise value is the insn generated to do the store. */ | |
177 static rtx spill_reg_store[FIRST_PSEUDO_REGISTER]; | |
178 | |
179 /* This is the register that was stored with spill_reg_store. This is a | |
180 copy of reload_out / reload_out_reg when the value was stored; if | |
181 reload_out is a MEM, spill_reg_stored_to will be set to reload_out_reg. */ | |
182 static rtx spill_reg_stored_to[FIRST_PSEUDO_REGISTER]; | |
183 | |
184 /* This table is the inverse mapping of spill_regs: | |
185 indexed by hard reg number, | |
186 it contains the position of that reg in spill_regs, | |
187 or -1 for something that is not in spill_regs. | |
188 | |
189 ?!? This is no longer accurate. */ | |
190 static short spill_reg_order[FIRST_PSEUDO_REGISTER]; | |
191 | |
192 /* This reg set indicates registers that can't be used as spill registers for | |
193 the currently processed insn. These are the hard registers which are live | |
194 during the insn, but not allocated to pseudos, as well as fixed | |
195 registers. */ | |
196 static HARD_REG_SET bad_spill_regs; | |
197 | |
198 /* These are the hard registers that can't be used as spill register for any | |
199 insn. This includes registers used for user variables and registers that | |
200 we can't eliminate. A register that appears in this set also can't be used | |
201 to retry register allocation. */ | |
202 static HARD_REG_SET bad_spill_regs_global; | |
203 | |
204 /* Describes order of use of registers for reloading | |
205 of spilled pseudo-registers. `n_spills' is the number of | |
206 elements that are actually valid; new ones are added at the end. | |
207 | |
208 Both spill_regs and spill_reg_order are used on two occasions: | |
209 once during find_reload_regs, where they keep track of the spill registers | |
210 for a single insn, but also during reload_as_needed where they show all | |
211 the registers ever used by reload. For the latter case, the information | |
212 is calculated during finish_spills. */ | |
213 static short spill_regs[FIRST_PSEUDO_REGISTER]; | |
214 | |
215 /* This vector of reg sets indicates, for each pseudo, which hard registers | |
216 may not be used for retrying global allocation because the register was | |
217 formerly spilled from one of them. If we allowed reallocating a pseudo to | |
218 a register that it was already allocated to, reload might not | |
219 terminate. */ | |
220 static HARD_REG_SET *pseudo_previous_regs; | |
221 | |
222 /* This vector of reg sets indicates, for each pseudo, which hard | |
223 registers may not be used for retrying global allocation because they | |
224 are used as spill registers during one of the insns in which the | |
225 pseudo is live. */ | |
226 static HARD_REG_SET *pseudo_forbidden_regs; | |
227 | |
228 /* All hard regs that have been used as spill registers for any insn are | |
229 marked in this set. */ | |
230 static HARD_REG_SET used_spill_regs; | |
231 | |
232 /* Index of last register assigned as a spill register. We allocate in | |
233 a round-robin fashion. */ | |
234 static int last_spill_reg; | |
235 | |
236 /* Nonzero if indirect addressing is supported on the machine; this means | |
237 that spilling (REG n) does not require reloading it into a register in | |
238 order to do (MEM (REG n)) or (MEM (PLUS (REG n) (CONST_INT c))). The | |
239 value indicates the level of indirect addressing supported, e.g., two | |
240 means that (MEM (MEM (REG n))) is also valid if (REG n) does not get | |
241 a hard register. */ | |
242 static char spill_indirect_levels; | |
243 | |
244 /* Nonzero if indirect addressing is supported when the innermost MEM is | |
245 of the form (MEM (SYMBOL_REF sym)). It is assumed that the level to | |
246 which these are valid is the same as spill_indirect_levels, above. */ | |
247 char indirect_symref_ok; | |
248 | |
249 /* Nonzero if an address (plus (reg frame_pointer) (reg ...)) is valid. */ | |
250 char double_reg_address_ok; | |
251 | |
252 /* Record the stack slot for each spilled hard register. */ | |
253 static rtx spill_stack_slot[FIRST_PSEUDO_REGISTER]; | |
254 | |
255 /* Width allocated so far for that stack slot. */ | |
256 static unsigned int spill_stack_slot_width[FIRST_PSEUDO_REGISTER]; | |
257 | |
258 /* Record which pseudos needed to be spilled. */ | |
259 static regset_head spilled_pseudos; | |
260 | |
261 /* Record which pseudos changed their allocation in finish_spills. */ | |
262 static regset_head changed_allocation_pseudos; | |
263 | |
264 /* Used for communication between order_regs_for_reload and count_pseudo. | |
265 Used to avoid counting one pseudo twice. */ | |
266 static regset_head pseudos_counted; | |
267 | |
268 /* First uid used by insns created by reload in this function. | |
269 Used in find_equiv_reg. */ | |
270 int reload_first_uid; | |
271 | |
272 /* Flag set by local-alloc or global-alloc if anything is live in | |
273 a call-clobbered reg across calls. */ | |
274 int caller_save_needed; | |
275 | |
276 /* Set to 1 while reload_as_needed is operating. | |
277 Required by some machines to handle any generated moves differently. */ | |
278 int reload_in_progress = 0; | |
279 | |
280 /* These arrays record the insn_code of insns that may be needed to | |
281 perform input and output reloads of special objects. They provide a | |
282 place to pass a scratch register. */ | |
283 enum insn_code reload_in_optab[NUM_MACHINE_MODES]; | |
284 enum insn_code reload_out_optab[NUM_MACHINE_MODES]; | |
285 | |
286 /* This obstack is used for allocation of rtl during register elimination. | |
287 The allocated storage can be freed once find_reloads has processed the | |
288 insn. */ | |
289 static struct obstack reload_obstack; | |
290 | |
291 /* Points to the beginning of the reload_obstack. All insn_chain structures | |
292 are allocated first. */ | |
293 static char *reload_startobj; | |
294 | |
295 /* The point after all insn_chain structures. Used to quickly deallocate | |
296 memory allocated in copy_reloads during calculate_needs_all_insns. */ | |
297 static char *reload_firstobj; | |
298 | |
299 /* This points before all local rtl generated by register elimination. | |
300 Used to quickly free all memory after processing one insn. */ | |
301 static char *reload_insn_firstobj; | |
302 | |
303 /* List of insn_chain instructions, one for every insn that reload needs to | |
304 examine. */ | |
305 struct insn_chain *reload_insn_chain; | |
306 | |
307 /* List of all insns needing reloads. */ | |
308 static struct insn_chain *insns_need_reload; | |
309 | |
310 /* This structure is used to record information about register eliminations. | |
311 Each array entry describes one possible way of eliminating a register | |
312 in favor of another. If there is more than one way of eliminating a | |
313 particular register, the most preferred should be specified first. */ | |
314 | |
315 struct elim_table | |
316 { | |
317 int from; /* Register number to be eliminated. */ | |
318 int to; /* Register number used as replacement. */ | |
319 HOST_WIDE_INT initial_offset; /* Initial difference between values. */ | |
320 int can_eliminate; /* Nonzero if this elimination can be done. */ | |
321 int can_eliminate_previous; /* Value of CAN_ELIMINATE in previous scan over | |
322 insns made by reload. */ | |
323 HOST_WIDE_INT offset; /* Current offset between the two regs. */ | |
324 HOST_WIDE_INT previous_offset;/* Offset at end of previous insn. */ | |
325 int ref_outside_mem; /* "to" has been referenced outside a MEM. */ | |
326 rtx from_rtx; /* REG rtx for the register to be eliminated. | |
327 We cannot simply compare the number since | |
328 we might then spuriously replace a hard | |
329 register corresponding to a pseudo | |
330 assigned to the reg to be eliminated. */ | |
331 rtx to_rtx; /* REG rtx for the replacement. */ | |
332 }; | |
333 | |
334 static struct elim_table *reg_eliminate = 0; | |
335 | |
336 /* This is an intermediate structure to initialize the table. It has | |
337 exactly the members provided by ELIMINABLE_REGS. */ | |
338 static const struct elim_table_1 | |
339 { | |
340 const int from; | |
341 const int to; | |
342 } reg_eliminate_1[] = | |
343 | |
344 /* If a set of eliminable registers was specified, define the table from it. | |
345 Otherwise, default to the normal case of the frame pointer being | |
346 replaced by the stack pointer. */ | |
347 | |
348 #ifdef ELIMINABLE_REGS | |
349 ELIMINABLE_REGS; | |
350 #else | |
351 {{ FRAME_POINTER_REGNUM, STACK_POINTER_REGNUM}}; | |
352 #endif | |
353 | |
354 #define NUM_ELIMINABLE_REGS ARRAY_SIZE (reg_eliminate_1) | |
355 | |
356 /* Record the number of pending eliminations that have an offset not equal | |
357 to their initial offset. If nonzero, we use a new copy of each | |
358 replacement result in any insns encountered. */ | |
359 int num_not_at_initial_offset; | |
360 | |
361 /* Count the number of registers that we may be able to eliminate. */ | |
362 static int num_eliminable; | |
363 /* And the number of registers that are equivalent to a constant that | |
364 can be eliminated to frame_pointer / arg_pointer + constant. */ | |
365 static int num_eliminable_invariants; | |
366 | |
367 /* For each label, we record the offset of each elimination. If we reach | |
368 a label by more than one path and an offset differs, we cannot do the | |
369 elimination. This information is indexed by the difference of the | |
370 number of the label and the first label number. We can't offset the | |
371 pointer itself as this can cause problems on machines with segmented | |
372 memory. The first table is an array of flags that records whether we | |
373 have yet encountered a label and the second table is an array of arrays, | |
374 one entry in the latter array for each elimination. */ | |
375 | |
376 static int first_label_num; | |
377 static char *offsets_known_at; | |
378 static HOST_WIDE_INT (*offsets_at)[NUM_ELIMINABLE_REGS]; | |
379 | |
380 /* Number of labels in the current function. */ | |
381 | |
382 static int num_labels; | |
383 | |
384 static void replace_pseudos_in (rtx *, enum machine_mode, rtx); | |
385 static void maybe_fix_stack_asms (void); | |
386 static void copy_reloads (struct insn_chain *); | |
387 static void calculate_needs_all_insns (int); | |
388 static int find_reg (struct insn_chain *, int); | |
389 static void find_reload_regs (struct insn_chain *); | |
390 static void select_reload_regs (void); | |
391 static void delete_caller_save_insns (void); | |
392 | |
393 static void spill_failure (rtx, enum reg_class); | |
394 static void count_spilled_pseudo (int, int, int); | |
395 static void delete_dead_insn (rtx); | |
396 static void alter_reg (int, int, bool); | |
397 static void set_label_offsets (rtx, rtx, int); | |
398 static void check_eliminable_occurrences (rtx); | |
399 static void elimination_effects (rtx, enum machine_mode); | |
400 static int eliminate_regs_in_insn (rtx, int); | |
401 static void update_eliminable_offsets (void); | |
402 static void mark_not_eliminable (rtx, const_rtx, void *); | |
403 static void set_initial_elim_offsets (void); | |
404 static bool verify_initial_elim_offsets (void); | |
405 static void set_initial_label_offsets (void); | |
406 static void set_offsets_for_label (rtx); | |
407 static void init_elim_table (void); | |
408 static void update_eliminables (HARD_REG_SET *); | |
409 static void spill_hard_reg (unsigned int, int); | |
410 static int finish_spills (int); | |
411 static void scan_paradoxical_subregs (rtx); | |
412 static void count_pseudo (int); | |
413 static void order_regs_for_reload (struct insn_chain *); | |
414 static void reload_as_needed (int); | |
415 static void forget_old_reloads_1 (rtx, const_rtx, void *); | |
416 static void forget_marked_reloads (regset); | |
417 static int reload_reg_class_lower (const void *, const void *); | |
418 static void mark_reload_reg_in_use (unsigned int, int, enum reload_type, | |
419 enum machine_mode); | |
420 static void clear_reload_reg_in_use (unsigned int, int, enum reload_type, | |
421 enum machine_mode); | |
422 static int reload_reg_free_p (unsigned int, int, enum reload_type); | |
423 static int reload_reg_free_for_value_p (int, int, int, enum reload_type, | |
424 rtx, rtx, int, int); | |
425 static int free_for_value_p (int, enum machine_mode, int, enum reload_type, | |
426 rtx, rtx, int, int); | |
427 static int reload_reg_reaches_end_p (unsigned int, int, enum reload_type); | |
428 static int allocate_reload_reg (struct insn_chain *, int, int); | |
429 static int conflicts_with_override (rtx); | |
430 static void failed_reload (rtx, int); | |
431 static int set_reload_reg (int, int); | |
432 static void choose_reload_regs_init (struct insn_chain *, rtx *); | |
433 static void choose_reload_regs (struct insn_chain *); | |
434 static void merge_assigned_reloads (rtx); | |
435 static void emit_input_reload_insns (struct insn_chain *, struct reload *, | |
436 rtx, int); | |
437 static void emit_output_reload_insns (struct insn_chain *, struct reload *, | |
438 int); | |
439 static void do_input_reload (struct insn_chain *, struct reload *, int); | |
440 static void do_output_reload (struct insn_chain *, struct reload *, int); | |
441 static void emit_reload_insns (struct insn_chain *); | |
442 static void delete_output_reload (rtx, int, int, rtx); | |
443 static void delete_address_reloads (rtx, rtx); | |
444 static void delete_address_reloads_1 (rtx, rtx, rtx); | |
445 static rtx inc_for_reload (rtx, rtx, rtx, int); | |
446 #ifdef AUTO_INC_DEC | |
447 static void add_auto_inc_notes (rtx, rtx); | |
448 #endif | |
449 static void copy_eh_notes (rtx, rtx); | |
450 static void substitute (rtx *, const_rtx, rtx); | |
451 static bool gen_reload_chain_without_interm_reg_p (int, int); | |
452 static int reloads_conflict (int, int); | |
453 static rtx gen_reload (rtx, rtx, int, enum reload_type); | |
454 static rtx emit_insn_if_valid_for_reload (rtx); | |
455 | |
456 /* Initialize the reload pass. This is called at the beginning of compilation | |
457 and may be called again if the target is reinitialized. */ | |
458 | |
459 void | |
460 init_reload (void) | |
461 { | |
462 int i; | |
463 | |
464 /* Often (MEM (REG n)) is still valid even if (REG n) is put on the stack. | |
465 Set spill_indirect_levels to the number of levels such addressing is | |
466 permitted, zero if it is not permitted at all. */ | |
467 | |
468 rtx tem | |
469 = gen_rtx_MEM (Pmode, | |
470 gen_rtx_PLUS (Pmode, | |
471 gen_rtx_REG (Pmode, | |
472 LAST_VIRTUAL_REGISTER + 1), | |
473 GEN_INT (4))); | |
474 spill_indirect_levels = 0; | |
475 | |
476 while (memory_address_p (QImode, tem)) | |
477 { | |
478 spill_indirect_levels++; | |
479 tem = gen_rtx_MEM (Pmode, tem); | |
480 } | |
481 | |
482 /* See if indirect addressing is valid for (MEM (SYMBOL_REF ...)). */ | |
483 | |
484 tem = gen_rtx_MEM (Pmode, gen_rtx_SYMBOL_REF (Pmode, "foo")); | |
485 indirect_symref_ok = memory_address_p (QImode, tem); | |
486 | |
487 /* See if reg+reg is a valid (and offsettable) address. */ | |
488 | |
489 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) | |
490 { | |
491 tem = gen_rtx_PLUS (Pmode, | |
492 gen_rtx_REG (Pmode, HARD_FRAME_POINTER_REGNUM), | |
493 gen_rtx_REG (Pmode, i)); | |
494 | |
495 /* This way, we make sure that reg+reg is an offsettable address. */ | |
496 tem = plus_constant (tem, 4); | |
497 | |
498 if (memory_address_p (QImode, tem)) | |
499 { | |
500 double_reg_address_ok = 1; | |
501 break; | |
502 } | |
503 } | |
504 | |
505 /* Initialize obstack for our rtl allocation. */ | |
506 gcc_obstack_init (&reload_obstack); | |
507 reload_startobj = XOBNEWVAR (&reload_obstack, char, 0); | |
508 | |
509 INIT_REG_SET (&spilled_pseudos); | |
510 INIT_REG_SET (&changed_allocation_pseudos); | |
511 INIT_REG_SET (&pseudos_counted); | |
512 } | |
513 | |
514 /* List of insn chains that are currently unused. */ | |
515 static struct insn_chain *unused_insn_chains = 0; | |
516 | |
517 /* Allocate an empty insn_chain structure. */ | |
518 struct insn_chain * | |
519 new_insn_chain (void) | |
520 { | |
521 struct insn_chain *c; | |
522 | |
523 if (unused_insn_chains == 0) | |
524 { | |
525 c = XOBNEW (&reload_obstack, struct insn_chain); | |
526 INIT_REG_SET (&c->live_throughout); | |
527 INIT_REG_SET (&c->dead_or_set); | |
528 } | |
529 else | |
530 { | |
531 c = unused_insn_chains; | |
532 unused_insn_chains = c->next; | |
533 } | |
534 c->is_caller_save_insn = 0; | |
535 c->need_operand_change = 0; | |
536 c->need_reload = 0; | |
537 c->need_elim = 0; | |
538 return c; | |
539 } | |
540 | |
541 /* Small utility function to set all regs in hard reg set TO which are | |
542 allocated to pseudos in regset FROM. */ | |
543 | |
544 void | |
545 compute_use_by_pseudos (HARD_REG_SET *to, regset from) | |
546 { | |
547 unsigned int regno; | |
548 reg_set_iterator rsi; | |
549 | |
550 EXECUTE_IF_SET_IN_REG_SET (from, FIRST_PSEUDO_REGISTER, regno, rsi) | |
551 { | |
552 int r = reg_renumber[regno]; | |
553 | |
554 if (r < 0) | |
555 { | |
556 /* reload_combine uses the information from DF_LIVE_IN, | |
557 which might still contain registers that have not | |
558 actually been allocated since they have an | |
559 equivalence. */ | |
560 gcc_assert (ira_conflicts_p || reload_completed); | |
561 } | |
562 else | |
563 add_to_hard_reg_set (to, PSEUDO_REGNO_MODE (regno), r); | |
564 } | |
565 } | |
566 | |
567 /* Replace all pseudos found in LOC with their corresponding | |
568 equivalences. */ | |
569 | |
570 static void | |
571 replace_pseudos_in (rtx *loc, enum machine_mode mem_mode, rtx usage) | |
572 { | |
573 rtx x = *loc; | |
574 enum rtx_code code; | |
575 const char *fmt; | |
576 int i, j; | |
577 | |
578 if (! x) | |
579 return; | |
580 | |
581 code = GET_CODE (x); | |
582 if (code == REG) | |
583 { | |
584 unsigned int regno = REGNO (x); | |
585 | |
586 if (regno < FIRST_PSEUDO_REGISTER) | |
587 return; | |
588 | |
589 x = eliminate_regs (x, mem_mode, usage); | |
590 if (x != *loc) | |
591 { | |
592 *loc = x; | |
593 replace_pseudos_in (loc, mem_mode, usage); | |
594 return; | |
595 } | |
596 | |
597 if (reg_equiv_constant[regno]) | |
598 *loc = reg_equiv_constant[regno]; | |
599 else if (reg_equiv_mem[regno]) | |
600 *loc = reg_equiv_mem[regno]; | |
601 else if (reg_equiv_address[regno]) | |
602 *loc = gen_rtx_MEM (GET_MODE (x), reg_equiv_address[regno]); | |
603 else | |
604 { | |
605 gcc_assert (!REG_P (regno_reg_rtx[regno]) | |
606 || REGNO (regno_reg_rtx[regno]) != regno); | |
607 *loc = regno_reg_rtx[regno]; | |
608 } | |
609 | |
610 return; | |
611 } | |
612 else if (code == MEM) | |
613 { | |
614 replace_pseudos_in (& XEXP (x, 0), GET_MODE (x), usage); | |
615 return; | |
616 } | |
617 | |
618 /* Process each of our operands recursively. */ | |
619 fmt = GET_RTX_FORMAT (code); | |
620 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++) | |
621 if (*fmt == 'e') | |
622 replace_pseudos_in (&XEXP (x, i), mem_mode, usage); | |
623 else if (*fmt == 'E') | |
624 for (j = 0; j < XVECLEN (x, i); j++) | |
625 replace_pseudos_in (& XVECEXP (x, i, j), mem_mode, usage); | |
626 } | |
627 | |
628 /* Determine if the current function has an exception receiver block | |
629 that reaches the exit block via non-exceptional edges */ | |
630 | |
631 static bool | |
632 has_nonexceptional_receiver (void) | |
633 { | |
634 edge e; | |
635 edge_iterator ei; | |
636 basic_block *tos, *worklist, bb; | |
637 | |
638 /* If we're not optimizing, then just err on the safe side. */ | |
639 if (!optimize) | |
640 return true; | |
641 | |
642 /* First determine which blocks can reach exit via normal paths. */ | |
643 tos = worklist = XNEWVEC (basic_block, n_basic_blocks + 1); | |
644 | |
645 FOR_EACH_BB (bb) | |
646 bb->flags &= ~BB_REACHABLE; | |
647 | |
648 /* Place the exit block on our worklist. */ | |
649 EXIT_BLOCK_PTR->flags |= BB_REACHABLE; | |
650 *tos++ = EXIT_BLOCK_PTR; | |
651 | |
652 /* Iterate: find everything reachable from what we've already seen. */ | |
653 while (tos != worklist) | |
654 { | |
655 bb = *--tos; | |
656 | |
657 FOR_EACH_EDGE (e, ei, bb->preds) | |
658 if (!(e->flags & EDGE_ABNORMAL)) | |
659 { | |
660 basic_block src = e->src; | |
661 | |
662 if (!(src->flags & BB_REACHABLE)) | |
663 { | |
664 src->flags |= BB_REACHABLE; | |
665 *tos++ = src; | |
666 } | |
667 } | |
668 } | |
669 free (worklist); | |
670 | |
671 /* Now see if there's a reachable block with an exceptional incoming | |
672 edge. */ | |
673 FOR_EACH_BB (bb) | |
674 if (bb->flags & BB_REACHABLE) | |
675 FOR_EACH_EDGE (e, ei, bb->preds) | |
676 if (e->flags & EDGE_ABNORMAL) | |
677 return true; | |
678 | |
679 /* No exceptional block reached exit unexceptionally. */ | |
680 return false; | |
681 } | |
682 | |
683 | |
684 /* Global variables used by reload and its subroutines. */ | |
685 | |
686 /* Set during calculate_needs if an insn needs register elimination. */ | |
687 static int something_needs_elimination; | |
688 /* Set during calculate_needs if an insn needs an operand changed. */ | |
689 static int something_needs_operands_changed; | |
690 | |
691 /* Nonzero means we couldn't get enough spill regs. */ | |
692 static int failure; | |
693 | |
694 /* Temporary array of pseudo-register number. */ | |
695 static int *temp_pseudo_reg_arr; | |
696 | |
697 /* Main entry point for the reload pass. | |
698 | |
699 FIRST is the first insn of the function being compiled. | |
700 | |
701 GLOBAL nonzero means we were called from global_alloc | |
702 and should attempt to reallocate any pseudoregs that we | |
703 displace from hard regs we will use for reloads. | |
704 If GLOBAL is zero, we do not have enough information to do that, | |
705 so any pseudo reg that is spilled must go to the stack. | |
706 | |
707 Return value is nonzero if reload failed | |
708 and we must not do any more for this function. */ | |
709 | |
710 int | |
711 reload (rtx first, int global) | |
712 { | |
713 int i, n; | |
714 rtx insn; | |
715 struct elim_table *ep; | |
716 basic_block bb; | |
717 | |
718 /* Make sure even insns with volatile mem refs are recognizable. */ | |
719 init_recog (); | |
720 | |
721 failure = 0; | |
722 | |
723 reload_firstobj = XOBNEWVAR (&reload_obstack, char, 0); | |
724 | |
725 /* Make sure that the last insn in the chain | |
726 is not something that needs reloading. */ | |
727 emit_note (NOTE_INSN_DELETED); | |
728 | |
729 /* Enable find_equiv_reg to distinguish insns made by reload. */ | |
730 reload_first_uid = get_max_uid (); | |
731 | |
732 #ifdef SECONDARY_MEMORY_NEEDED | |
733 /* Initialize the secondary memory table. */ | |
734 clear_secondary_mem (); | |
735 #endif | |
736 | |
737 /* We don't have a stack slot for any spill reg yet. */ | |
738 memset (spill_stack_slot, 0, sizeof spill_stack_slot); | |
739 memset (spill_stack_slot_width, 0, sizeof spill_stack_slot_width); | |
740 | |
741 /* Initialize the save area information for caller-save, in case some | |
742 are needed. */ | |
743 init_save_areas (); | |
744 | |
745 /* Compute which hard registers are now in use | |
746 as homes for pseudo registers. | |
747 This is done here rather than (eg) in global_alloc | |
748 because this point is reached even if not optimizing. */ | |
749 for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++) | |
750 mark_home_live (i); | |
751 | |
752 /* A function that has a nonlocal label that can reach the exit | |
753 block via non-exceptional paths must save all call-saved | |
754 registers. */ | |
755 if (cfun->has_nonlocal_label | |
756 && has_nonexceptional_receiver ()) | |
757 crtl->saves_all_registers = 1; | |
758 | |
759 if (crtl->saves_all_registers) | |
760 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) | |
761 if (! call_used_regs[i] && ! fixed_regs[i] && ! LOCAL_REGNO (i)) | |
762 df_set_regs_ever_live (i, true); | |
763 | |
764 /* Find all the pseudo registers that didn't get hard regs | |
765 but do have known equivalent constants or memory slots. | |
766 These include parameters (known equivalent to parameter slots) | |
767 and cse'd or loop-moved constant memory addresses. | |
768 | |
769 Record constant equivalents in reg_equiv_constant | |
770 so they will be substituted by find_reloads. | |
771 Record memory equivalents in reg_mem_equiv so they can | |
772 be substituted eventually by altering the REG-rtx's. */ | |
773 | |
774 reg_equiv_constant = XCNEWVEC (rtx, max_regno); | |
775 reg_equiv_invariant = XCNEWVEC (rtx, max_regno); | |
776 reg_equiv_mem = XCNEWVEC (rtx, max_regno); | |
777 reg_equiv_alt_mem_list = XCNEWVEC (rtx, max_regno); | |
778 reg_equiv_address = XCNEWVEC (rtx, max_regno); | |
779 reg_max_ref_width = XCNEWVEC (unsigned int, max_regno); | |
780 reg_old_renumber = XCNEWVEC (short, max_regno); | |
781 memcpy (reg_old_renumber, reg_renumber, max_regno * sizeof (short)); | |
782 pseudo_forbidden_regs = XNEWVEC (HARD_REG_SET, max_regno); | |
783 pseudo_previous_regs = XCNEWVEC (HARD_REG_SET, max_regno); | |
784 | |
785 CLEAR_HARD_REG_SET (bad_spill_regs_global); | |
786 | |
787 /* Look for REG_EQUIV notes; record what each pseudo is equivalent | |
788 to. Also find all paradoxical subregs and find largest such for | |
789 each pseudo. */ | |
790 | |
791 num_eliminable_invariants = 0; | |
792 for (insn = first; insn; insn = NEXT_INSN (insn)) | |
793 { | |
794 rtx set = single_set (insn); | |
795 | |
796 /* We may introduce USEs that we want to remove at the end, so | |
797 we'll mark them with QImode. Make sure there are no | |
798 previously-marked insns left by say regmove. */ | |
799 if (INSN_P (insn) && GET_CODE (PATTERN (insn)) == USE | |
800 && GET_MODE (insn) != VOIDmode) | |
801 PUT_MODE (insn, VOIDmode); | |
802 | |
803 if (INSN_P (insn)) | |
804 scan_paradoxical_subregs (PATTERN (insn)); | |
805 | |
806 if (set != 0 && REG_P (SET_DEST (set))) | |
807 { | |
808 rtx note = find_reg_note (insn, REG_EQUIV, NULL_RTX); | |
809 rtx x; | |
810 | |
811 if (! note) | |
812 continue; | |
813 | |
814 i = REGNO (SET_DEST (set)); | |
815 x = XEXP (note, 0); | |
816 | |
817 if (i <= LAST_VIRTUAL_REGISTER) | |
818 continue; | |
819 | |
820 if (! function_invariant_p (x) | |
821 || ! flag_pic | |
822 /* A function invariant is often CONSTANT_P but may | |
823 include a register. We promise to only pass | |
824 CONSTANT_P objects to LEGITIMATE_PIC_OPERAND_P. */ | |
825 || (CONSTANT_P (x) | |
826 && LEGITIMATE_PIC_OPERAND_P (x))) | |
827 { | |
828 /* It can happen that a REG_EQUIV note contains a MEM | |
829 that is not a legitimate memory operand. As later | |
830 stages of reload assume that all addresses found | |
831 in the reg_equiv_* arrays were originally legitimate, | |
832 we ignore such REG_EQUIV notes. */ | |
833 if (memory_operand (x, VOIDmode)) | |
834 { | |
835 /* Always unshare the equivalence, so we can | |
836 substitute into this insn without touching the | |
837 equivalence. */ | |
838 reg_equiv_memory_loc[i] = copy_rtx (x); | |
839 } | |
840 else if (function_invariant_p (x)) | |
841 { | |
842 if (GET_CODE (x) == PLUS) | |
843 { | |
844 /* This is PLUS of frame pointer and a constant, | |
845 and might be shared. Unshare it. */ | |
846 reg_equiv_invariant[i] = copy_rtx (x); | |
847 num_eliminable_invariants++; | |
848 } | |
849 else if (x == frame_pointer_rtx || x == arg_pointer_rtx) | |
850 { | |
851 reg_equiv_invariant[i] = x; | |
852 num_eliminable_invariants++; | |
853 } | |
854 else if (LEGITIMATE_CONSTANT_P (x)) | |
855 reg_equiv_constant[i] = x; | |
856 else | |
857 { | |
858 reg_equiv_memory_loc[i] | |
859 = force_const_mem (GET_MODE (SET_DEST (set)), x); | |
860 if (! reg_equiv_memory_loc[i]) | |
861 reg_equiv_init[i] = NULL_RTX; | |
862 } | |
863 } | |
864 else | |
865 { | |
866 reg_equiv_init[i] = NULL_RTX; | |
867 continue; | |
868 } | |
869 } | |
870 else | |
871 reg_equiv_init[i] = NULL_RTX; | |
872 } | |
873 } | |
874 | |
875 if (dump_file) | |
876 for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++) | |
877 if (reg_equiv_init[i]) | |
878 { | |
879 fprintf (dump_file, "init_insns for %u: ", i); | |
880 print_inline_rtx (dump_file, reg_equiv_init[i], 20); | |
881 fprintf (dump_file, "\n"); | |
882 } | |
883 | |
884 init_elim_table (); | |
885 | |
886 first_label_num = get_first_label_num (); | |
887 num_labels = max_label_num () - first_label_num; | |
888 | |
889 /* Allocate the tables used to store offset information at labels. */ | |
890 /* We used to use alloca here, but the size of what it would try to | |
891 allocate would occasionally cause it to exceed the stack limit and | |
892 cause a core dump. */ | |
893 offsets_known_at = XNEWVEC (char, num_labels); | |
894 offsets_at = (HOST_WIDE_INT (*)[NUM_ELIMINABLE_REGS]) xmalloc (num_labels * NUM_ELIMINABLE_REGS * sizeof (HOST_WIDE_INT)); | |
895 | |
896 /* Alter each pseudo-reg rtx to contain its hard reg number. Assign | |
897 stack slots to the pseudos that lack hard regs or equivalents. | |
898 Do not touch virtual registers. */ | |
899 | |
900 temp_pseudo_reg_arr = XNEWVEC (int, max_regno - LAST_VIRTUAL_REGISTER - 1); | |
901 for (n = 0, i = LAST_VIRTUAL_REGISTER + 1; i < max_regno; i++) | |
902 temp_pseudo_reg_arr[n++] = i; | |
903 | |
904 if (ira_conflicts_p) | |
905 /* Ask IRA to order pseudo-registers for better stack slot | |
906 sharing. */ | |
907 ira_sort_regnos_for_alter_reg (temp_pseudo_reg_arr, n, reg_max_ref_width); | |
908 | |
909 for (i = 0; i < n; i++) | |
910 alter_reg (temp_pseudo_reg_arr[i], -1, false); | |
911 | |
912 /* If we have some registers we think can be eliminated, scan all insns to | |
913 see if there is an insn that sets one of these registers to something | |
914 other than itself plus a constant. If so, the register cannot be | |
915 eliminated. Doing this scan here eliminates an extra pass through the | |
916 main reload loop in the most common case where register elimination | |
917 cannot be done. */ | |
918 for (insn = first; insn && num_eliminable; insn = NEXT_INSN (insn)) | |
919 if (INSN_P (insn)) | |
920 note_stores (PATTERN (insn), mark_not_eliminable, NULL); | |
921 | |
922 maybe_fix_stack_asms (); | |
923 | |
924 insns_need_reload = 0; | |
925 something_needs_elimination = 0; | |
926 | |
927 /* Initialize to -1, which means take the first spill register. */ | |
928 last_spill_reg = -1; | |
929 | |
930 /* Spill any hard regs that we know we can't eliminate. */ | |
931 CLEAR_HARD_REG_SET (used_spill_regs); | |
932 /* There can be multiple ways to eliminate a register; | |
933 they should be listed adjacently. | |
934 Elimination for any register fails only if all possible ways fail. */ | |
935 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ) | |
936 { | |
937 int from = ep->from; | |
938 int can_eliminate = 0; | |
939 do | |
940 { | |
941 can_eliminate |= ep->can_eliminate; | |
942 ep++; | |
943 } | |
944 while (ep < ®_eliminate[NUM_ELIMINABLE_REGS] && ep->from == from); | |
945 if (! can_eliminate) | |
946 spill_hard_reg (from, 1); | |
947 } | |
948 | |
949 #if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM | |
950 if (frame_pointer_needed) | |
951 spill_hard_reg (HARD_FRAME_POINTER_REGNUM, 1); | |
952 #endif | |
953 finish_spills (global); | |
954 | |
955 /* From now on, we may need to generate moves differently. We may also | |
956 allow modifications of insns which cause them to not be recognized. | |
957 Any such modifications will be cleaned up during reload itself. */ | |
958 reload_in_progress = 1; | |
959 | |
960 /* This loop scans the entire function each go-round | |
961 and repeats until one repetition spills no additional hard regs. */ | |
962 for (;;) | |
963 { | |
964 int something_changed; | |
965 int did_spill; | |
966 HOST_WIDE_INT starting_frame_size; | |
967 | |
968 starting_frame_size = get_frame_size (); | |
969 | |
970 set_initial_elim_offsets (); | |
971 set_initial_label_offsets (); | |
972 | |
973 /* For each pseudo register that has an equivalent location defined, | |
974 try to eliminate any eliminable registers (such as the frame pointer) | |
975 assuming initial offsets for the replacement register, which | |
976 is the normal case. | |
977 | |
978 If the resulting location is directly addressable, substitute | |
979 the MEM we just got directly for the old REG. | |
980 | |
981 If it is not addressable but is a constant or the sum of a hard reg | |
982 and constant, it is probably not addressable because the constant is | |
983 out of range, in that case record the address; we will generate | |
984 hairy code to compute the address in a register each time it is | |
985 needed. Similarly if it is a hard register, but one that is not | |
986 valid as an address register. | |
987 | |
988 If the location is not addressable, but does not have one of the | |
989 above forms, assign a stack slot. We have to do this to avoid the | |
990 potential of producing lots of reloads if, e.g., a location involves | |
991 a pseudo that didn't get a hard register and has an equivalent memory | |
992 location that also involves a pseudo that didn't get a hard register. | |
993 | |
994 Perhaps at some point we will improve reload_when_needed handling | |
995 so this problem goes away. But that's very hairy. */ | |
996 | |
997 for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++) | |
998 if (reg_renumber[i] < 0 && reg_equiv_memory_loc[i]) | |
999 { | |
1000 rtx x = eliminate_regs (reg_equiv_memory_loc[i], 0, NULL_RTX); | |
1001 | |
1002 if (strict_memory_address_p (GET_MODE (regno_reg_rtx[i]), | |
1003 XEXP (x, 0))) | |
1004 reg_equiv_mem[i] = x, reg_equiv_address[i] = 0; | |
1005 else if (CONSTANT_P (XEXP (x, 0)) | |
1006 || (REG_P (XEXP (x, 0)) | |
1007 && REGNO (XEXP (x, 0)) < FIRST_PSEUDO_REGISTER) | |
1008 || (GET_CODE (XEXP (x, 0)) == PLUS | |
1009 && REG_P (XEXP (XEXP (x, 0), 0)) | |
1010 && (REGNO (XEXP (XEXP (x, 0), 0)) | |
1011 < FIRST_PSEUDO_REGISTER) | |
1012 && CONSTANT_P (XEXP (XEXP (x, 0), 1)))) | |
1013 reg_equiv_address[i] = XEXP (x, 0), reg_equiv_mem[i] = 0; | |
1014 else | |
1015 { | |
1016 /* Make a new stack slot. Then indicate that something | |
1017 changed so we go back and recompute offsets for | |
1018 eliminable registers because the allocation of memory | |
1019 below might change some offset. reg_equiv_{mem,address} | |
1020 will be set up for this pseudo on the next pass around | |
1021 the loop. */ | |
1022 reg_equiv_memory_loc[i] = 0; | |
1023 reg_equiv_init[i] = 0; | |
1024 alter_reg (i, -1, true); | |
1025 } | |
1026 } | |
1027 | |
1028 if (caller_save_needed) | |
1029 setup_save_areas (); | |
1030 | |
1031 /* If we allocated another stack slot, redo elimination bookkeeping. */ | |
1032 if (starting_frame_size != get_frame_size ()) | |
1033 continue; | |
1034 if (starting_frame_size && crtl->stack_alignment_needed) | |
1035 { | |
1036 /* If we have a stack frame, we must align it now. The | |
1037 stack size may be a part of the offset computation for | |
1038 register elimination. So if this changes the stack size, | |
1039 then repeat the elimination bookkeeping. We don't | |
1040 realign when there is no stack, as that will cause a | |
1041 stack frame when none is needed should | |
1042 STARTING_FRAME_OFFSET not be already aligned to | |
1043 STACK_BOUNDARY. */ | |
1044 assign_stack_local (BLKmode, 0, crtl->stack_alignment_needed); | |
1045 if (starting_frame_size != get_frame_size ()) | |
1046 continue; | |
1047 } | |
1048 | |
1049 if (caller_save_needed) | |
1050 { | |
1051 save_call_clobbered_regs (); | |
1052 /* That might have allocated new insn_chain structures. */ | |
1053 reload_firstobj = XOBNEWVAR (&reload_obstack, char, 0); | |
1054 } | |
1055 | |
1056 calculate_needs_all_insns (global); | |
1057 | |
1058 if (! ira_conflicts_p) | |
1059 /* Don't do it for IRA. We need this info because we don't | |
1060 change live_throughout and dead_or_set for chains when IRA | |
1061 is used. */ | |
1062 CLEAR_REG_SET (&spilled_pseudos); | |
1063 | |
1064 did_spill = 0; | |
1065 | |
1066 something_changed = 0; | |
1067 | |
1068 /* If we allocated any new memory locations, make another pass | |
1069 since it might have changed elimination offsets. */ | |
1070 if (starting_frame_size != get_frame_size ()) | |
1071 something_changed = 1; | |
1072 | |
1073 /* Even if the frame size remained the same, we might still have | |
1074 changed elimination offsets, e.g. if find_reloads called | |
1075 force_const_mem requiring the back end to allocate a constant | |
1076 pool base register that needs to be saved on the stack. */ | |
1077 else if (!verify_initial_elim_offsets ()) | |
1078 something_changed = 1; | |
1079 | |
1080 { | |
1081 HARD_REG_SET to_spill; | |
1082 CLEAR_HARD_REG_SET (to_spill); | |
1083 update_eliminables (&to_spill); | |
1084 AND_COMPL_HARD_REG_SET (used_spill_regs, to_spill); | |
1085 | |
1086 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) | |
1087 if (TEST_HARD_REG_BIT (to_spill, i)) | |
1088 { | |
1089 spill_hard_reg (i, 1); | |
1090 did_spill = 1; | |
1091 | |
1092 /* Regardless of the state of spills, if we previously had | |
1093 a register that we thought we could eliminate, but now can | |
1094 not eliminate, we must run another pass. | |
1095 | |
1096 Consider pseudos which have an entry in reg_equiv_* which | |
1097 reference an eliminable register. We must make another pass | |
1098 to update reg_equiv_* so that we do not substitute in the | |
1099 old value from when we thought the elimination could be | |
1100 performed. */ | |
1101 something_changed = 1; | |
1102 } | |
1103 } | |
1104 | |
1105 select_reload_regs (); | |
1106 if (failure) | |
1107 goto failed; | |
1108 | |
1109 if (insns_need_reload != 0 || did_spill) | |
1110 something_changed |= finish_spills (global); | |
1111 | |
1112 if (! something_changed) | |
1113 break; | |
1114 | |
1115 if (caller_save_needed) | |
1116 delete_caller_save_insns (); | |
1117 | |
1118 obstack_free (&reload_obstack, reload_firstobj); | |
1119 } | |
1120 | |
1121 /* If global-alloc was run, notify it of any register eliminations we have | |
1122 done. */ | |
1123 if (global) | |
1124 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++) | |
1125 if (ep->can_eliminate) | |
1126 mark_elimination (ep->from, ep->to); | |
1127 | |
1128 /* If a pseudo has no hard reg, delete the insns that made the equivalence. | |
1129 If that insn didn't set the register (i.e., it copied the register to | |
1130 memory), just delete that insn instead of the equivalencing insn plus | |
1131 anything now dead. If we call delete_dead_insn on that insn, we may | |
1132 delete the insn that actually sets the register if the register dies | |
1133 there and that is incorrect. */ | |
1134 | |
1135 for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++) | |
1136 { | |
1137 if (reg_renumber[i] < 0 && reg_equiv_init[i] != 0) | |
1138 { | |
1139 rtx list; | |
1140 for (list = reg_equiv_init[i]; list; list = XEXP (list, 1)) | |
1141 { | |
1142 rtx equiv_insn = XEXP (list, 0); | |
1143 | |
1144 /* If we already deleted the insn or if it may trap, we can't | |
1145 delete it. The latter case shouldn't happen, but can | |
1146 if an insn has a variable address, gets a REG_EH_REGION | |
1147 note added to it, and then gets converted into a load | |
1148 from a constant address. */ | |
1149 if (NOTE_P (equiv_insn) | |
1150 || can_throw_internal (equiv_insn)) | |
1151 ; | |
1152 else if (reg_set_p (regno_reg_rtx[i], PATTERN (equiv_insn))) | |
1153 delete_dead_insn (equiv_insn); | |
1154 else | |
1155 SET_INSN_DELETED (equiv_insn); | |
1156 } | |
1157 } | |
1158 } | |
1159 | |
1160 /* Use the reload registers where necessary | |
1161 by generating move instructions to move the must-be-register | |
1162 values into or out of the reload registers. */ | |
1163 | |
1164 if (insns_need_reload != 0 || something_needs_elimination | |
1165 || something_needs_operands_changed) | |
1166 { | |
1167 HOST_WIDE_INT old_frame_size = get_frame_size (); | |
1168 | |
1169 reload_as_needed (global); | |
1170 | |
1171 gcc_assert (old_frame_size == get_frame_size ()); | |
1172 | |
1173 gcc_assert (verify_initial_elim_offsets ()); | |
1174 } | |
1175 | |
1176 /* If we were able to eliminate the frame pointer, show that it is no | |
1177 longer live at the start of any basic block. If it ls live by | |
1178 virtue of being in a pseudo, that pseudo will be marked live | |
1179 and hence the frame pointer will be known to be live via that | |
1180 pseudo. */ | |
1181 | |
1182 if (! frame_pointer_needed) | |
1183 FOR_EACH_BB (bb) | |
1184 bitmap_clear_bit (df_get_live_in (bb), HARD_FRAME_POINTER_REGNUM); | |
1185 | |
1186 /* Come here (with failure set nonzero) if we can't get enough spill | |
1187 regs. */ | |
1188 failed: | |
1189 | |
1190 CLEAR_REG_SET (&changed_allocation_pseudos); | |
1191 CLEAR_REG_SET (&spilled_pseudos); | |
1192 reload_in_progress = 0; | |
1193 | |
1194 /* Now eliminate all pseudo regs by modifying them into | |
1195 their equivalent memory references. | |
1196 The REG-rtx's for the pseudos are modified in place, | |
1197 so all insns that used to refer to them now refer to memory. | |
1198 | |
1199 For a reg that has a reg_equiv_address, all those insns | |
1200 were changed by reloading so that no insns refer to it any longer; | |
1201 but the DECL_RTL of a variable decl may refer to it, | |
1202 and if so this causes the debugging info to mention the variable. */ | |
1203 | |
1204 for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++) | |
1205 { | |
1206 rtx addr = 0; | |
1207 | |
1208 if (reg_equiv_mem[i]) | |
1209 addr = XEXP (reg_equiv_mem[i], 0); | |
1210 | |
1211 if (reg_equiv_address[i]) | |
1212 addr = reg_equiv_address[i]; | |
1213 | |
1214 if (addr) | |
1215 { | |
1216 if (reg_renumber[i] < 0) | |
1217 { | |
1218 rtx reg = regno_reg_rtx[i]; | |
1219 | |
1220 REG_USERVAR_P (reg) = 0; | |
1221 PUT_CODE (reg, MEM); | |
1222 XEXP (reg, 0) = addr; | |
1223 if (reg_equiv_memory_loc[i]) | |
1224 MEM_COPY_ATTRIBUTES (reg, reg_equiv_memory_loc[i]); | |
1225 else | |
1226 { | |
1227 MEM_IN_STRUCT_P (reg) = MEM_SCALAR_P (reg) = 0; | |
1228 MEM_ATTRS (reg) = 0; | |
1229 } | |
1230 MEM_NOTRAP_P (reg) = 1; | |
1231 } | |
1232 else if (reg_equiv_mem[i]) | |
1233 XEXP (reg_equiv_mem[i], 0) = addr; | |
1234 } | |
1235 } | |
1236 | |
1237 /* We must set reload_completed now since the cleanup_subreg_operands call | |
1238 below will re-recognize each insn and reload may have generated insns | |
1239 which are only valid during and after reload. */ | |
1240 reload_completed = 1; | |
1241 | |
1242 /* Make a pass over all the insns and delete all USEs which we inserted | |
1243 only to tag a REG_EQUAL note on them. Remove all REG_DEAD and REG_UNUSED | |
1244 notes. Delete all CLOBBER insns, except those that refer to the return | |
1245 value and the special mem:BLK CLOBBERs added to prevent the scheduler | |
1246 from misarranging variable-array code, and simplify (subreg (reg)) | |
1247 operands. Strip and regenerate REG_INC notes that may have been moved | |
1248 around. */ | |
1249 | |
1250 for (insn = first; insn; insn = NEXT_INSN (insn)) | |
1251 if (INSN_P (insn)) | |
1252 { | |
1253 rtx *pnote; | |
1254 | |
1255 if (CALL_P (insn)) | |
1256 replace_pseudos_in (& CALL_INSN_FUNCTION_USAGE (insn), | |
1257 VOIDmode, CALL_INSN_FUNCTION_USAGE (insn)); | |
1258 | |
1259 if ((GET_CODE (PATTERN (insn)) == USE | |
1260 /* We mark with QImode USEs introduced by reload itself. */ | |
1261 && (GET_MODE (insn) == QImode | |
1262 || find_reg_note (insn, REG_EQUAL, NULL_RTX))) | |
1263 || (GET_CODE (PATTERN (insn)) == CLOBBER | |
1264 && (!MEM_P (XEXP (PATTERN (insn), 0)) | |
1265 || GET_MODE (XEXP (PATTERN (insn), 0)) != BLKmode | |
1266 || (GET_CODE (XEXP (XEXP (PATTERN (insn), 0), 0)) != SCRATCH | |
1267 && XEXP (XEXP (PATTERN (insn), 0), 0) | |
1268 != stack_pointer_rtx)) | |
1269 && (!REG_P (XEXP (PATTERN (insn), 0)) | |
1270 || ! REG_FUNCTION_VALUE_P (XEXP (PATTERN (insn), 0))))) | |
1271 { | |
1272 delete_insn (insn); | |
1273 continue; | |
1274 } | |
1275 | |
1276 /* Some CLOBBERs may survive until here and still reference unassigned | |
1277 pseudos with const equivalent, which may in turn cause ICE in later | |
1278 passes if the reference remains in place. */ | |
1279 if (GET_CODE (PATTERN (insn)) == CLOBBER) | |
1280 replace_pseudos_in (& XEXP (PATTERN (insn), 0), | |
1281 VOIDmode, PATTERN (insn)); | |
1282 | |
1283 /* Discard obvious no-ops, even without -O. This optimization | |
1284 is fast and doesn't interfere with debugging. */ | |
1285 if (NONJUMP_INSN_P (insn) | |
1286 && GET_CODE (PATTERN (insn)) == SET | |
1287 && REG_P (SET_SRC (PATTERN (insn))) | |
1288 && REG_P (SET_DEST (PATTERN (insn))) | |
1289 && (REGNO (SET_SRC (PATTERN (insn))) | |
1290 == REGNO (SET_DEST (PATTERN (insn))))) | |
1291 { | |
1292 delete_insn (insn); | |
1293 continue; | |
1294 } | |
1295 | |
1296 pnote = ®_NOTES (insn); | |
1297 while (*pnote != 0) | |
1298 { | |
1299 if (REG_NOTE_KIND (*pnote) == REG_DEAD | |
1300 || REG_NOTE_KIND (*pnote) == REG_UNUSED | |
1301 || REG_NOTE_KIND (*pnote) == REG_INC) | |
1302 *pnote = XEXP (*pnote, 1); | |
1303 else | |
1304 pnote = &XEXP (*pnote, 1); | |
1305 } | |
1306 | |
1307 #ifdef AUTO_INC_DEC | |
1308 add_auto_inc_notes (insn, PATTERN (insn)); | |
1309 #endif | |
1310 | |
1311 /* Simplify (subreg (reg)) if it appears as an operand. */ | |
1312 cleanup_subreg_operands (insn); | |
1313 | |
1314 /* Clean up invalid ASMs so that they don't confuse later passes. | |
1315 See PR 21299. */ | |
1316 if (asm_noperands (PATTERN (insn)) >= 0) | |
1317 { | |
1318 extract_insn (insn); | |
1319 if (!constrain_operands (1)) | |
1320 { | |
1321 error_for_asm (insn, | |
1322 "%<asm%> operand has impossible constraints"); | |
1323 delete_insn (insn); | |
1324 continue; | |
1325 } | |
1326 } | |
1327 } | |
1328 | |
1329 /* If we are doing generic stack checking, give a warning if this | |
1330 function's frame size is larger than we expect. */ | |
1331 if (flag_stack_check == GENERIC_STACK_CHECK) | |
1332 { | |
1333 HOST_WIDE_INT size = get_frame_size () + STACK_CHECK_FIXED_FRAME_SIZE; | |
1334 static int verbose_warned = 0; | |
1335 | |
1336 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) | |
1337 if (df_regs_ever_live_p (i) && ! fixed_regs[i] && call_used_regs[i]) | |
1338 size += UNITS_PER_WORD; | |
1339 | |
1340 if (size > STACK_CHECK_MAX_FRAME_SIZE) | |
1341 { | |
1342 warning (0, "frame size too large for reliable stack checking"); | |
1343 if (! verbose_warned) | |
1344 { | |
1345 warning (0, "try reducing the number of local variables"); | |
1346 verbose_warned = 1; | |
1347 } | |
1348 } | |
1349 } | |
1350 | |
1351 /* Indicate that we no longer have known memory locations or constants. */ | |
1352 if (reg_equiv_constant) | |
1353 free (reg_equiv_constant); | |
1354 if (reg_equiv_invariant) | |
1355 free (reg_equiv_invariant); | |
1356 reg_equiv_constant = 0; | |
1357 reg_equiv_invariant = 0; | |
1358 VEC_free (rtx, gc, reg_equiv_memory_loc_vec); | |
1359 reg_equiv_memory_loc = 0; | |
1360 | |
1361 free (temp_pseudo_reg_arr); | |
1362 | |
1363 if (offsets_known_at) | |
1364 free (offsets_known_at); | |
1365 if (offsets_at) | |
1366 free (offsets_at); | |
1367 | |
1368 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) | |
1369 if (reg_equiv_alt_mem_list[i]) | |
1370 free_EXPR_LIST_list (®_equiv_alt_mem_list[i]); | |
1371 free (reg_equiv_alt_mem_list); | |
1372 | |
1373 free (reg_equiv_mem); | |
1374 reg_equiv_init = 0; | |
1375 free (reg_equiv_address); | |
1376 free (reg_max_ref_width); | |
1377 free (reg_old_renumber); | |
1378 free (pseudo_previous_regs); | |
1379 free (pseudo_forbidden_regs); | |
1380 | |
1381 CLEAR_HARD_REG_SET (used_spill_regs); | |
1382 for (i = 0; i < n_spills; i++) | |
1383 SET_HARD_REG_BIT (used_spill_regs, spill_regs[i]); | |
1384 | |
1385 /* Free all the insn_chain structures at once. */ | |
1386 obstack_free (&reload_obstack, reload_startobj); | |
1387 unused_insn_chains = 0; | |
1388 fixup_abnormal_edges (); | |
1389 | |
1390 /* Replacing pseudos with their memory equivalents might have | |
1391 created shared rtx. Subsequent passes would get confused | |
1392 by this, so unshare everything here. */ | |
1393 unshare_all_rtl_again (first); | |
1394 | |
1395 #ifdef STACK_BOUNDARY | |
1396 /* init_emit has set the alignment of the hard frame pointer | |
1397 to STACK_BOUNDARY. It is very likely no longer valid if | |
1398 the hard frame pointer was used for register allocation. */ | |
1399 if (!frame_pointer_needed) | |
1400 REGNO_POINTER_ALIGN (HARD_FRAME_POINTER_REGNUM) = BITS_PER_UNIT; | |
1401 #endif | |
1402 | |
1403 return failure; | |
1404 } | |
1405 | |
1406 /* Yet another special case. Unfortunately, reg-stack forces people to | |
1407 write incorrect clobbers in asm statements. These clobbers must not | |
1408 cause the register to appear in bad_spill_regs, otherwise we'll call | |
1409 fatal_insn later. We clear the corresponding regnos in the live | |
1410 register sets to avoid this. | |
1411 The whole thing is rather sick, I'm afraid. */ | |
1412 | |
1413 static void | |
1414 maybe_fix_stack_asms (void) | |
1415 { | |
1416 #ifdef STACK_REGS | |
1417 const char *constraints[MAX_RECOG_OPERANDS]; | |
1418 enum machine_mode operand_mode[MAX_RECOG_OPERANDS]; | |
1419 struct insn_chain *chain; | |
1420 | |
1421 for (chain = reload_insn_chain; chain != 0; chain = chain->next) | |
1422 { | |
1423 int i, noperands; | |
1424 HARD_REG_SET clobbered, allowed; | |
1425 rtx pat; | |
1426 | |
1427 if (! INSN_P (chain->insn) | |
1428 || (noperands = asm_noperands (PATTERN (chain->insn))) < 0) | |
1429 continue; | |
1430 pat = PATTERN (chain->insn); | |
1431 if (GET_CODE (pat) != PARALLEL) | |
1432 continue; | |
1433 | |
1434 CLEAR_HARD_REG_SET (clobbered); | |
1435 CLEAR_HARD_REG_SET (allowed); | |
1436 | |
1437 /* First, make a mask of all stack regs that are clobbered. */ | |
1438 for (i = 0; i < XVECLEN (pat, 0); i++) | |
1439 { | |
1440 rtx t = XVECEXP (pat, 0, i); | |
1441 if (GET_CODE (t) == CLOBBER && STACK_REG_P (XEXP (t, 0))) | |
1442 SET_HARD_REG_BIT (clobbered, REGNO (XEXP (t, 0))); | |
1443 } | |
1444 | |
1445 /* Get the operand values and constraints out of the insn. */ | |
1446 decode_asm_operands (pat, recog_data.operand, recog_data.operand_loc, | |
1447 constraints, operand_mode, NULL); | |
1448 | |
1449 /* For every operand, see what registers are allowed. */ | |
1450 for (i = 0; i < noperands; i++) | |
1451 { | |
1452 const char *p = constraints[i]; | |
1453 /* For every alternative, we compute the class of registers allowed | |
1454 for reloading in CLS, and merge its contents into the reg set | |
1455 ALLOWED. */ | |
1456 int cls = (int) NO_REGS; | |
1457 | |
1458 for (;;) | |
1459 { | |
1460 char c = *p; | |
1461 | |
1462 if (c == '\0' || c == ',' || c == '#') | |
1463 { | |
1464 /* End of one alternative - mark the regs in the current | |
1465 class, and reset the class. */ | |
1466 IOR_HARD_REG_SET (allowed, reg_class_contents[cls]); | |
1467 cls = NO_REGS; | |
1468 p++; | |
1469 if (c == '#') | |
1470 do { | |
1471 c = *p++; | |
1472 } while (c != '\0' && c != ','); | |
1473 if (c == '\0') | |
1474 break; | |
1475 continue; | |
1476 } | |
1477 | |
1478 switch (c) | |
1479 { | |
1480 case '=': case '+': case '*': case '%': case '?': case '!': | |
1481 case '0': case '1': case '2': case '3': case '4': case '<': | |
1482 case '>': case 'V': case 'o': case '&': case 'E': case 'F': | |
1483 case 's': case 'i': case 'n': case 'X': case 'I': case 'J': | |
1484 case 'K': case 'L': case 'M': case 'N': case 'O': case 'P': | |
1485 case TARGET_MEM_CONSTRAINT: | |
1486 break; | |
1487 | |
1488 case 'p': | |
1489 cls = (int) reg_class_subunion[cls] | |
1490 [(int) base_reg_class (VOIDmode, ADDRESS, SCRATCH)]; | |
1491 break; | |
1492 | |
1493 case 'g': | |
1494 case 'r': | |
1495 cls = (int) reg_class_subunion[cls][(int) GENERAL_REGS]; | |
1496 break; | |
1497 | |
1498 default: | |
1499 if (EXTRA_ADDRESS_CONSTRAINT (c, p)) | |
1500 cls = (int) reg_class_subunion[cls] | |
1501 [(int) base_reg_class (VOIDmode, ADDRESS, SCRATCH)]; | |
1502 else | |
1503 cls = (int) reg_class_subunion[cls] | |
1504 [(int) REG_CLASS_FROM_CONSTRAINT (c, p)]; | |
1505 } | |
1506 p += CONSTRAINT_LEN (c, p); | |
1507 } | |
1508 } | |
1509 /* Those of the registers which are clobbered, but allowed by the | |
1510 constraints, must be usable as reload registers. So clear them | |
1511 out of the life information. */ | |
1512 AND_HARD_REG_SET (allowed, clobbered); | |
1513 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) | |
1514 if (TEST_HARD_REG_BIT (allowed, i)) | |
1515 { | |
1516 CLEAR_REGNO_REG_SET (&chain->live_throughout, i); | |
1517 CLEAR_REGNO_REG_SET (&chain->dead_or_set, i); | |
1518 } | |
1519 } | |
1520 | |
1521 #endif | |
1522 } | |
1523 | |
1524 /* Copy the global variables n_reloads and rld into the corresponding elts | |
1525 of CHAIN. */ | |
1526 static void | |
1527 copy_reloads (struct insn_chain *chain) | |
1528 { | |
1529 chain->n_reloads = n_reloads; | |
1530 chain->rld = XOBNEWVEC (&reload_obstack, struct reload, n_reloads); | |
1531 memcpy (chain->rld, rld, n_reloads * sizeof (struct reload)); | |
1532 reload_insn_firstobj = XOBNEWVAR (&reload_obstack, char, 0); | |
1533 } | |
1534 | |
1535 /* Walk the chain of insns, and determine for each whether it needs reloads | |
1536 and/or eliminations. Build the corresponding insns_need_reload list, and | |
1537 set something_needs_elimination as appropriate. */ | |
1538 static void | |
1539 calculate_needs_all_insns (int global) | |
1540 { | |
1541 struct insn_chain **pprev_reload = &insns_need_reload; | |
1542 struct insn_chain *chain, *next = 0; | |
1543 | |
1544 something_needs_elimination = 0; | |
1545 | |
1546 reload_insn_firstobj = XOBNEWVAR (&reload_obstack, char, 0); | |
1547 for (chain = reload_insn_chain; chain != 0; chain = next) | |
1548 { | |
1549 rtx insn = chain->insn; | |
1550 | |
1551 next = chain->next; | |
1552 | |
1553 /* Clear out the shortcuts. */ | |
1554 chain->n_reloads = 0; | |
1555 chain->need_elim = 0; | |
1556 chain->need_reload = 0; | |
1557 chain->need_operand_change = 0; | |
1558 | |
1559 /* If this is a label, a JUMP_INSN, or has REG_NOTES (which might | |
1560 include REG_LABEL_OPERAND and REG_LABEL_TARGET), we need to see | |
1561 what effects this has on the known offsets at labels. */ | |
1562 | |
1563 if (LABEL_P (insn) || JUMP_P (insn) | |
1564 || (INSN_P (insn) && REG_NOTES (insn) != 0)) | |
1565 set_label_offsets (insn, insn, 0); | |
1566 | |
1567 if (INSN_P (insn)) | |
1568 { | |
1569 rtx old_body = PATTERN (insn); | |
1570 int old_code = INSN_CODE (insn); | |
1571 rtx old_notes = REG_NOTES (insn); | |
1572 int did_elimination = 0; | |
1573 int operands_changed = 0; | |
1574 rtx set = single_set (insn); | |
1575 | |
1576 /* Skip insns that only set an equivalence. */ | |
1577 if (set && REG_P (SET_DEST (set)) | |
1578 && reg_renumber[REGNO (SET_DEST (set))] < 0 | |
1579 && (reg_equiv_constant[REGNO (SET_DEST (set))] | |
1580 || (reg_equiv_invariant[REGNO (SET_DEST (set))])) | |
1581 && reg_equiv_init[REGNO (SET_DEST (set))]) | |
1582 continue; | |
1583 | |
1584 /* If needed, eliminate any eliminable registers. */ | |
1585 if (num_eliminable || num_eliminable_invariants) | |
1586 did_elimination = eliminate_regs_in_insn (insn, 0); | |
1587 | |
1588 /* Analyze the instruction. */ | |
1589 operands_changed = find_reloads (insn, 0, spill_indirect_levels, | |
1590 global, spill_reg_order); | |
1591 | |
1592 /* If a no-op set needs more than one reload, this is likely | |
1593 to be something that needs input address reloads. We | |
1594 can't get rid of this cleanly later, and it is of no use | |
1595 anyway, so discard it now. | |
1596 We only do this when expensive_optimizations is enabled, | |
1597 since this complements reload inheritance / output | |
1598 reload deletion, and it can make debugging harder. */ | |
1599 if (flag_expensive_optimizations && n_reloads > 1) | |
1600 { | |
1601 rtx set = single_set (insn); | |
1602 if (set | |
1603 && | |
1604 ((SET_SRC (set) == SET_DEST (set) | |
1605 && REG_P (SET_SRC (set)) | |
1606 && REGNO (SET_SRC (set)) >= FIRST_PSEUDO_REGISTER) | |
1607 || (REG_P (SET_SRC (set)) && REG_P (SET_DEST (set)) | |
1608 && reg_renumber[REGNO (SET_SRC (set))] < 0 | |
1609 && reg_renumber[REGNO (SET_DEST (set))] < 0 | |
1610 && reg_equiv_memory_loc[REGNO (SET_SRC (set))] != NULL | |
1611 && reg_equiv_memory_loc[REGNO (SET_DEST (set))] != NULL | |
1612 && rtx_equal_p (reg_equiv_memory_loc | |
1613 [REGNO (SET_SRC (set))], | |
1614 reg_equiv_memory_loc | |
1615 [REGNO (SET_DEST (set))])))) | |
1616 { | |
1617 if (ira_conflicts_p) | |
1618 /* Inform IRA about the insn deletion. */ | |
1619 ira_mark_memory_move_deletion (REGNO (SET_DEST (set)), | |
1620 REGNO (SET_SRC (set))); | |
1621 delete_insn (insn); | |
1622 /* Delete it from the reload chain. */ | |
1623 if (chain->prev) | |
1624 chain->prev->next = next; | |
1625 else | |
1626 reload_insn_chain = next; | |
1627 if (next) | |
1628 next->prev = chain->prev; | |
1629 chain->next = unused_insn_chains; | |
1630 unused_insn_chains = chain; | |
1631 continue; | |
1632 } | |
1633 } | |
1634 if (num_eliminable) | |
1635 update_eliminable_offsets (); | |
1636 | |
1637 /* Remember for later shortcuts which insns had any reloads or | |
1638 register eliminations. */ | |
1639 chain->need_elim = did_elimination; | |
1640 chain->need_reload = n_reloads > 0; | |
1641 chain->need_operand_change = operands_changed; | |
1642 | |
1643 /* Discard any register replacements done. */ | |
1644 if (did_elimination) | |
1645 { | |
1646 obstack_free (&reload_obstack, reload_insn_firstobj); | |
1647 PATTERN (insn) = old_body; | |
1648 INSN_CODE (insn) = old_code; | |
1649 REG_NOTES (insn) = old_notes; | |
1650 something_needs_elimination = 1; | |
1651 } | |
1652 | |
1653 something_needs_operands_changed |= operands_changed; | |
1654 | |
1655 if (n_reloads != 0) | |
1656 { | |
1657 copy_reloads (chain); | |
1658 *pprev_reload = chain; | |
1659 pprev_reload = &chain->next_need_reload; | |
1660 } | |
1661 } | |
1662 } | |
1663 *pprev_reload = 0; | |
1664 } | |
1665 | |
1666 /* Comparison function for qsort to decide which of two reloads | |
1667 should be handled first. *P1 and *P2 are the reload numbers. */ | |
1668 | |
1669 static int | |
1670 reload_reg_class_lower (const void *r1p, const void *r2p) | |
1671 { | |
1672 int r1 = *(const short *) r1p, r2 = *(const short *) r2p; | |
1673 int t; | |
1674 | |
1675 /* Consider required reloads before optional ones. */ | |
1676 t = rld[r1].optional - rld[r2].optional; | |
1677 if (t != 0) | |
1678 return t; | |
1679 | |
1680 /* Count all solitary classes before non-solitary ones. */ | |
1681 t = ((reg_class_size[(int) rld[r2].rclass] == 1) | |
1682 - (reg_class_size[(int) rld[r1].rclass] == 1)); | |
1683 if (t != 0) | |
1684 return t; | |
1685 | |
1686 /* Aside from solitaires, consider all multi-reg groups first. */ | |
1687 t = rld[r2].nregs - rld[r1].nregs; | |
1688 if (t != 0) | |
1689 return t; | |
1690 | |
1691 /* Consider reloads in order of increasing reg-class number. */ | |
1692 t = (int) rld[r1].rclass - (int) rld[r2].rclass; | |
1693 if (t != 0) | |
1694 return t; | |
1695 | |
1696 /* If reloads are equally urgent, sort by reload number, | |
1697 so that the results of qsort leave nothing to chance. */ | |
1698 return r1 - r2; | |
1699 } | |
1700 | |
1701 /* The cost of spilling each hard reg. */ | |
1702 static int spill_cost[FIRST_PSEUDO_REGISTER]; | |
1703 | |
1704 /* When spilling multiple hard registers, we use SPILL_COST for the first | |
1705 spilled hard reg and SPILL_ADD_COST for subsequent regs. SPILL_ADD_COST | |
1706 only the first hard reg for a multi-reg pseudo. */ | |
1707 static int spill_add_cost[FIRST_PSEUDO_REGISTER]; | |
1708 | |
1709 /* Map of hard regno to pseudo regno currently occupying the hard | |
1710 reg. */ | |
1711 static int hard_regno_to_pseudo_regno[FIRST_PSEUDO_REGISTER]; | |
1712 | |
1713 /* Update the spill cost arrays, considering that pseudo REG is live. */ | |
1714 | |
1715 static void | |
1716 count_pseudo (int reg) | |
1717 { | |
1718 int freq = REG_FREQ (reg); | |
1719 int r = reg_renumber[reg]; | |
1720 int nregs; | |
1721 | |
1722 if (REGNO_REG_SET_P (&pseudos_counted, reg) | |
1723 || REGNO_REG_SET_P (&spilled_pseudos, reg) | |
1724 /* Ignore spilled pseudo-registers which can be here only if IRA | |
1725 is used. */ | |
1726 || (ira_conflicts_p && r < 0)) | |
1727 return; | |
1728 | |
1729 SET_REGNO_REG_SET (&pseudos_counted, reg); | |
1730 | |
1731 gcc_assert (r >= 0); | |
1732 | |
1733 spill_add_cost[r] += freq; | |
1734 nregs = hard_regno_nregs[r][PSEUDO_REGNO_MODE (reg)]; | |
1735 while (nregs-- > 0) | |
1736 { | |
1737 hard_regno_to_pseudo_regno[r + nregs] = reg; | |
1738 spill_cost[r + nregs] += freq; | |
1739 } | |
1740 } | |
1741 | |
1742 /* Calculate the SPILL_COST and SPILL_ADD_COST arrays and determine the | |
1743 contents of BAD_SPILL_REGS for the insn described by CHAIN. */ | |
1744 | |
1745 static void | |
1746 order_regs_for_reload (struct insn_chain *chain) | |
1747 { | |
1748 unsigned i; | |
1749 HARD_REG_SET used_by_pseudos; | |
1750 HARD_REG_SET used_by_pseudos2; | |
1751 reg_set_iterator rsi; | |
1752 | |
1753 COPY_HARD_REG_SET (bad_spill_regs, fixed_reg_set); | |
1754 | |
1755 memset (spill_cost, 0, sizeof spill_cost); | |
1756 memset (spill_add_cost, 0, sizeof spill_add_cost); | |
1757 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) | |
1758 hard_regno_to_pseudo_regno[i] = -1; | |
1759 | |
1760 /* Count number of uses of each hard reg by pseudo regs allocated to it | |
1761 and then order them by decreasing use. First exclude hard registers | |
1762 that are live in or across this insn. */ | |
1763 | |
1764 REG_SET_TO_HARD_REG_SET (used_by_pseudos, &chain->live_throughout); | |
1765 REG_SET_TO_HARD_REG_SET (used_by_pseudos2, &chain->dead_or_set); | |
1766 IOR_HARD_REG_SET (bad_spill_regs, used_by_pseudos); | |
1767 IOR_HARD_REG_SET (bad_spill_regs, used_by_pseudos2); | |
1768 | |
1769 /* Now find out which pseudos are allocated to it, and update | |
1770 hard_reg_n_uses. */ | |
1771 CLEAR_REG_SET (&pseudos_counted); | |
1772 | |
1773 EXECUTE_IF_SET_IN_REG_SET | |
1774 (&chain->live_throughout, FIRST_PSEUDO_REGISTER, i, rsi) | |
1775 { | |
1776 count_pseudo (i); | |
1777 } | |
1778 EXECUTE_IF_SET_IN_REG_SET | |
1779 (&chain->dead_or_set, FIRST_PSEUDO_REGISTER, i, rsi) | |
1780 { | |
1781 count_pseudo (i); | |
1782 } | |
1783 CLEAR_REG_SET (&pseudos_counted); | |
1784 } | |
1785 | |
1786 /* Vector of reload-numbers showing the order in which the reloads should | |
1787 be processed. */ | |
1788 static short reload_order[MAX_RELOADS]; | |
1789 | |
1790 /* This is used to keep track of the spill regs used in one insn. */ | |
1791 static HARD_REG_SET used_spill_regs_local; | |
1792 | |
1793 /* We decided to spill hard register SPILLED, which has a size of | |
1794 SPILLED_NREGS. Determine how pseudo REG, which is live during the insn, | |
1795 is affected. We will add it to SPILLED_PSEUDOS if necessary, and we will | |
1796 update SPILL_COST/SPILL_ADD_COST. */ | |
1797 | |
1798 static void | |
1799 count_spilled_pseudo (int spilled, int spilled_nregs, int reg) | |
1800 { | |
1801 int freq = REG_FREQ (reg); | |
1802 int r = reg_renumber[reg]; | |
1803 int nregs = hard_regno_nregs[r][PSEUDO_REGNO_MODE (reg)]; | |
1804 | |
1805 /* Ignore spilled pseudo-registers which can be here only if IRA is | |
1806 used. */ | |
1807 if ((ira_conflicts_p && r < 0) | |
1808 || REGNO_REG_SET_P (&spilled_pseudos, reg) | |
1809 || spilled + spilled_nregs <= r || r + nregs <= spilled) | |
1810 return; | |
1811 | |
1812 SET_REGNO_REG_SET (&spilled_pseudos, reg); | |
1813 | |
1814 spill_add_cost[r] -= freq; | |
1815 while (nregs-- > 0) | |
1816 { | |
1817 hard_regno_to_pseudo_regno[r + nregs] = -1; | |
1818 spill_cost[r + nregs] -= freq; | |
1819 } | |
1820 } | |
1821 | |
1822 /* Find reload register to use for reload number ORDER. */ | |
1823 | |
1824 static int | |
1825 find_reg (struct insn_chain *chain, int order) | |
1826 { | |
1827 int rnum = reload_order[order]; | |
1828 struct reload *rl = rld + rnum; | |
1829 int best_cost = INT_MAX; | |
1830 int best_reg = -1; | |
1831 unsigned int i, j, n; | |
1832 int k; | |
1833 HARD_REG_SET not_usable; | |
1834 HARD_REG_SET used_by_other_reload; | |
1835 reg_set_iterator rsi; | |
1836 static int regno_pseudo_regs[FIRST_PSEUDO_REGISTER]; | |
1837 static int best_regno_pseudo_regs[FIRST_PSEUDO_REGISTER]; | |
1838 | |
1839 COPY_HARD_REG_SET (not_usable, bad_spill_regs); | |
1840 IOR_HARD_REG_SET (not_usable, bad_spill_regs_global); | |
1841 IOR_COMPL_HARD_REG_SET (not_usable, reg_class_contents[rl->rclass]); | |
1842 | |
1843 CLEAR_HARD_REG_SET (used_by_other_reload); | |
1844 for (k = 0; k < order; k++) | |
1845 { | |
1846 int other = reload_order[k]; | |
1847 | |
1848 if (rld[other].regno >= 0 && reloads_conflict (other, rnum)) | |
1849 for (j = 0; j < rld[other].nregs; j++) | |
1850 SET_HARD_REG_BIT (used_by_other_reload, rld[other].regno + j); | |
1851 } | |
1852 | |
1853 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) | |
1854 { | |
1855 #ifdef REG_ALLOC_ORDER | |
1856 unsigned int regno = reg_alloc_order[i]; | |
1857 #else | |
1858 unsigned int regno = i; | |
1859 #endif | |
1860 | |
1861 if (! TEST_HARD_REG_BIT (not_usable, regno) | |
1862 && ! TEST_HARD_REG_BIT (used_by_other_reload, regno) | |
1863 && HARD_REGNO_MODE_OK (regno, rl->mode)) | |
1864 { | |
1865 int this_cost = spill_cost[regno]; | |
1866 int ok = 1; | |
1867 unsigned int this_nregs = hard_regno_nregs[regno][rl->mode]; | |
1868 | |
1869 for (j = 1; j < this_nregs; j++) | |
1870 { | |
1871 this_cost += spill_add_cost[regno + j]; | |
1872 if ((TEST_HARD_REG_BIT (not_usable, regno + j)) | |
1873 || TEST_HARD_REG_BIT (used_by_other_reload, regno + j)) | |
1874 ok = 0; | |
1875 } | |
1876 if (! ok) | |
1877 continue; | |
1878 | |
1879 if (ira_conflicts_p) | |
1880 { | |
1881 /* Ask IRA to find a better pseudo-register for | |
1882 spilling. */ | |
1883 for (n = j = 0; j < this_nregs; j++) | |
1884 { | |
1885 int r = hard_regno_to_pseudo_regno[regno + j]; | |
1886 | |
1887 if (r < 0) | |
1888 continue; | |
1889 if (n == 0 || regno_pseudo_regs[n - 1] != r) | |
1890 regno_pseudo_regs[n++] = r; | |
1891 } | |
1892 regno_pseudo_regs[n++] = -1; | |
1893 if (best_reg < 0 | |
1894 || ira_better_spill_reload_regno_p (regno_pseudo_regs, | |
1895 best_regno_pseudo_regs, | |
1896 rl->in, rl->out, | |
1897 chain->insn)) | |
1898 { | |
1899 best_reg = regno; | |
1900 for (j = 0;; j++) | |
1901 { | |
1902 best_regno_pseudo_regs[j] = regno_pseudo_regs[j]; | |
1903 if (regno_pseudo_regs[j] < 0) | |
1904 break; | |
1905 } | |
1906 } | |
1907 continue; | |
1908 } | |
1909 | |
1910 if (rl->in && REG_P (rl->in) && REGNO (rl->in) == regno) | |
1911 this_cost--; | |
1912 if (rl->out && REG_P (rl->out) && REGNO (rl->out) == regno) | |
1913 this_cost--; | |
1914 if (this_cost < best_cost | |
1915 /* Among registers with equal cost, prefer caller-saved ones, or | |
1916 use REG_ALLOC_ORDER if it is defined. */ | |
1917 || (this_cost == best_cost | |
1918 #ifdef REG_ALLOC_ORDER | |
1919 && (inv_reg_alloc_order[regno] | |
1920 < inv_reg_alloc_order[best_reg]) | |
1921 #else | |
1922 && call_used_regs[regno] | |
1923 && ! call_used_regs[best_reg] | |
1924 #endif | |
1925 )) | |
1926 { | |
1927 best_reg = regno; | |
1928 best_cost = this_cost; | |
1929 } | |
1930 } | |
1931 } | |
1932 if (best_reg == -1) | |
1933 return 0; | |
1934 | |
1935 if (dump_file) | |
1936 fprintf (dump_file, "Using reg %d for reload %d\n", best_reg, rnum); | |
1937 | |
1938 rl->nregs = hard_regno_nregs[best_reg][rl->mode]; | |
1939 rl->regno = best_reg; | |
1940 | |
1941 EXECUTE_IF_SET_IN_REG_SET | |
1942 (&chain->live_throughout, FIRST_PSEUDO_REGISTER, j, rsi) | |
1943 { | |
1944 count_spilled_pseudo (best_reg, rl->nregs, j); | |
1945 } | |
1946 | |
1947 EXECUTE_IF_SET_IN_REG_SET | |
1948 (&chain->dead_or_set, FIRST_PSEUDO_REGISTER, j, rsi) | |
1949 { | |
1950 count_spilled_pseudo (best_reg, rl->nregs, j); | |
1951 } | |
1952 | |
1953 for (i = 0; i < rl->nregs; i++) | |
1954 { | |
1955 gcc_assert (spill_cost[best_reg + i] == 0); | |
1956 gcc_assert (spill_add_cost[best_reg + i] == 0); | |
1957 gcc_assert (hard_regno_to_pseudo_regno[best_reg + i] == -1); | |
1958 SET_HARD_REG_BIT (used_spill_regs_local, best_reg + i); | |
1959 } | |
1960 return 1; | |
1961 } | |
1962 | |
1963 /* Find more reload regs to satisfy the remaining need of an insn, which | |
1964 is given by CHAIN. | |
1965 Do it by ascending class number, since otherwise a reg | |
1966 might be spilled for a big class and might fail to count | |
1967 for a smaller class even though it belongs to that class. */ | |
1968 | |
1969 static void | |
1970 find_reload_regs (struct insn_chain *chain) | |
1971 { | |
1972 int i; | |
1973 | |
1974 /* In order to be certain of getting the registers we need, | |
1975 we must sort the reloads into order of increasing register class. | |
1976 Then our grabbing of reload registers will parallel the process | |
1977 that provided the reload registers. */ | |
1978 for (i = 0; i < chain->n_reloads; i++) | |
1979 { | |
1980 /* Show whether this reload already has a hard reg. */ | |
1981 if (chain->rld[i].reg_rtx) | |
1982 { | |
1983 int regno = REGNO (chain->rld[i].reg_rtx); | |
1984 chain->rld[i].regno = regno; | |
1985 chain->rld[i].nregs | |
1986 = hard_regno_nregs[regno][GET_MODE (chain->rld[i].reg_rtx)]; | |
1987 } | |
1988 else | |
1989 chain->rld[i].regno = -1; | |
1990 reload_order[i] = i; | |
1991 } | |
1992 | |
1993 n_reloads = chain->n_reloads; | |
1994 memcpy (rld, chain->rld, n_reloads * sizeof (struct reload)); | |
1995 | |
1996 CLEAR_HARD_REG_SET (used_spill_regs_local); | |
1997 | |
1998 if (dump_file) | |
1999 fprintf (dump_file, "Spilling for insn %d.\n", INSN_UID (chain->insn)); | |
2000 | |
2001 qsort (reload_order, n_reloads, sizeof (short), reload_reg_class_lower); | |
2002 | |
2003 /* Compute the order of preference for hard registers to spill. */ | |
2004 | |
2005 order_regs_for_reload (chain); | |
2006 | |
2007 for (i = 0; i < n_reloads; i++) | |
2008 { | |
2009 int r = reload_order[i]; | |
2010 | |
2011 /* Ignore reloads that got marked inoperative. */ | |
2012 if ((rld[r].out != 0 || rld[r].in != 0 || rld[r].secondary_p) | |
2013 && ! rld[r].optional | |
2014 && rld[r].regno == -1) | |
2015 if (! find_reg (chain, i)) | |
2016 { | |
2017 if (dump_file) | |
2018 fprintf (dump_file, "reload failure for reload %d\n", r); | |
2019 spill_failure (chain->insn, rld[r].rclass); | |
2020 failure = 1; | |
2021 return; | |
2022 } | |
2023 } | |
2024 | |
2025 COPY_HARD_REG_SET (chain->used_spill_regs, used_spill_regs_local); | |
2026 IOR_HARD_REG_SET (used_spill_regs, used_spill_regs_local); | |
2027 | |
2028 memcpy (chain->rld, rld, n_reloads * sizeof (struct reload)); | |
2029 } | |
2030 | |
2031 static void | |
2032 select_reload_regs (void) | |
2033 { | |
2034 struct insn_chain *chain; | |
2035 | |
2036 /* Try to satisfy the needs for each insn. */ | |
2037 for (chain = insns_need_reload; chain != 0; | |
2038 chain = chain->next_need_reload) | |
2039 find_reload_regs (chain); | |
2040 } | |
2041 | |
2042 /* Delete all insns that were inserted by emit_caller_save_insns during | |
2043 this iteration. */ | |
2044 static void | |
2045 delete_caller_save_insns (void) | |
2046 { | |
2047 struct insn_chain *c = reload_insn_chain; | |
2048 | |
2049 while (c != 0) | |
2050 { | |
2051 while (c != 0 && c->is_caller_save_insn) | |
2052 { | |
2053 struct insn_chain *next = c->next; | |
2054 rtx insn = c->insn; | |
2055 | |
2056 if (c == reload_insn_chain) | |
2057 reload_insn_chain = next; | |
2058 delete_insn (insn); | |
2059 | |
2060 if (next) | |
2061 next->prev = c->prev; | |
2062 if (c->prev) | |
2063 c->prev->next = next; | |
2064 c->next = unused_insn_chains; | |
2065 unused_insn_chains = c; | |
2066 c = next; | |
2067 } | |
2068 if (c != 0) | |
2069 c = c->next; | |
2070 } | |
2071 } | |
2072 | |
2073 /* Handle the failure to find a register to spill. | |
2074 INSN should be one of the insns which needed this particular spill reg. */ | |
2075 | |
2076 static void | |
2077 spill_failure (rtx insn, enum reg_class rclass) | |
2078 { | |
2079 if (asm_noperands (PATTERN (insn)) >= 0) | |
2080 error_for_asm (insn, "can't find a register in class %qs while " | |
2081 "reloading %<asm%>", | |
2082 reg_class_names[rclass]); | |
2083 else | |
2084 { | |
2085 error ("unable to find a register to spill in class %qs", | |
2086 reg_class_names[rclass]); | |
2087 | |
2088 if (dump_file) | |
2089 { | |
2090 fprintf (dump_file, "\nReloads for insn # %d\n", INSN_UID (insn)); | |
2091 debug_reload_to_stream (dump_file); | |
2092 } | |
2093 fatal_insn ("this is the insn:", insn); | |
2094 } | |
2095 } | |
2096 | |
2097 /* Delete an unneeded INSN and any previous insns who sole purpose is loading | |
2098 data that is dead in INSN. */ | |
2099 | |
2100 static void | |
2101 delete_dead_insn (rtx insn) | |
2102 { | |
2103 rtx prev = prev_real_insn (insn); | |
2104 rtx prev_dest; | |
2105 | |
2106 /* If the previous insn sets a register that dies in our insn, delete it | |
2107 too. */ | |
2108 if (prev && GET_CODE (PATTERN (prev)) == SET | |
2109 && (prev_dest = SET_DEST (PATTERN (prev)), REG_P (prev_dest)) | |
2110 && reg_mentioned_p (prev_dest, PATTERN (insn)) | |
2111 && find_regno_note (insn, REG_DEAD, REGNO (prev_dest)) | |
2112 && ! side_effects_p (SET_SRC (PATTERN (prev)))) | |
2113 delete_dead_insn (prev); | |
2114 | |
2115 SET_INSN_DELETED (insn); | |
2116 } | |
2117 | |
2118 /* Modify the home of pseudo-reg I. | |
2119 The new home is present in reg_renumber[I]. | |
2120 | |
2121 FROM_REG may be the hard reg that the pseudo-reg is being spilled from; | |
2122 or it may be -1, meaning there is none or it is not relevant. | |
2123 This is used so that all pseudos spilled from a given hard reg | |
2124 can share one stack slot. */ | |
2125 | |
2126 static void | |
2127 alter_reg (int i, int from_reg, bool dont_share_p) | |
2128 { | |
2129 /* When outputting an inline function, this can happen | |
2130 for a reg that isn't actually used. */ | |
2131 if (regno_reg_rtx[i] == 0) | |
2132 return; | |
2133 | |
2134 /* If the reg got changed to a MEM at rtl-generation time, | |
2135 ignore it. */ | |
2136 if (!REG_P (regno_reg_rtx[i])) | |
2137 return; | |
2138 | |
2139 /* Modify the reg-rtx to contain the new hard reg | |
2140 number or else to contain its pseudo reg number. */ | |
2141 SET_REGNO (regno_reg_rtx[i], | |
2142 reg_renumber[i] >= 0 ? reg_renumber[i] : i); | |
2143 | |
2144 /* If we have a pseudo that is needed but has no hard reg or equivalent, | |
2145 allocate a stack slot for it. */ | |
2146 | |
2147 if (reg_renumber[i] < 0 | |
2148 && REG_N_REFS (i) > 0 | |
2149 && reg_equiv_constant[i] == 0 | |
2150 && (reg_equiv_invariant[i] == 0 || reg_equiv_init[i] == 0) | |
2151 && reg_equiv_memory_loc[i] == 0) | |
2152 { | |
2153 rtx x = NULL_RTX; | |
2154 enum machine_mode mode = GET_MODE (regno_reg_rtx[i]); | |
2155 unsigned int inherent_size = PSEUDO_REGNO_BYTES (i); | |
2156 unsigned int inherent_align = GET_MODE_ALIGNMENT (mode); | |
2157 unsigned int total_size = MAX (inherent_size, reg_max_ref_width[i]); | |
2158 unsigned int min_align = reg_max_ref_width[i] * BITS_PER_UNIT; | |
2159 int adjust = 0; | |
2160 | |
2161 if (ira_conflicts_p) | |
2162 { | |
2163 /* Mark the spill for IRA. */ | |
2164 SET_REGNO_REG_SET (&spilled_pseudos, i); | |
2165 if (!dont_share_p) | |
2166 x = ira_reuse_stack_slot (i, inherent_size, total_size); | |
2167 } | |
2168 | |
2169 if (x) | |
2170 ; | |
2171 | |
2172 /* Each pseudo reg has an inherent size which comes from its own mode, | |
2173 and a total size which provides room for paradoxical subregs | |
2174 which refer to the pseudo reg in wider modes. | |
2175 | |
2176 We can use a slot already allocated if it provides both | |
2177 enough inherent space and enough total space. | |
2178 Otherwise, we allocate a new slot, making sure that it has no less | |
2179 inherent space, and no less total space, then the previous slot. */ | |
2180 else if (from_reg == -1 || (!dont_share_p && ira_conflicts_p)) | |
2181 { | |
2182 rtx stack_slot; | |
2183 | |
2184 /* No known place to spill from => no slot to reuse. */ | |
2185 x = assign_stack_local (mode, total_size, | |
2186 min_align > inherent_align | |
2187 || total_size > inherent_size ? -1 : 0); | |
2188 | |
2189 stack_slot = x; | |
2190 | |
2191 /* Cancel the big-endian correction done in assign_stack_local. | |
2192 Get the address of the beginning of the slot. This is so we | |
2193 can do a big-endian correction unconditionally below. */ | |
2194 if (BYTES_BIG_ENDIAN) | |
2195 { | |
2196 adjust = inherent_size - total_size; | |
2197 if (adjust) | |
2198 stack_slot | |
2199 = adjust_address_nv (x, mode_for_size (total_size | |
2200 * BITS_PER_UNIT, | |
2201 MODE_INT, 1), | |
2202 adjust); | |
2203 } | |
2204 | |
2205 if (! dont_share_p && ira_conflicts_p) | |
2206 /* Inform IRA about allocation a new stack slot. */ | |
2207 ira_mark_new_stack_slot (stack_slot, i, total_size); | |
2208 } | |
2209 | |
2210 /* Reuse a stack slot if possible. */ | |
2211 else if (spill_stack_slot[from_reg] != 0 | |
2212 && spill_stack_slot_width[from_reg] >= total_size | |
2213 && (GET_MODE_SIZE (GET_MODE (spill_stack_slot[from_reg])) | |
2214 >= inherent_size) | |
2215 && MEM_ALIGN (spill_stack_slot[from_reg]) >= min_align) | |
2216 x = spill_stack_slot[from_reg]; | |
2217 | |
2218 /* Allocate a bigger slot. */ | |
2219 else | |
2220 { | |
2221 /* Compute maximum size needed, both for inherent size | |
2222 and for total size. */ | |
2223 rtx stack_slot; | |
2224 | |
2225 if (spill_stack_slot[from_reg]) | |
2226 { | |
2227 if (GET_MODE_SIZE (GET_MODE (spill_stack_slot[from_reg])) | |
2228 > inherent_size) | |
2229 mode = GET_MODE (spill_stack_slot[from_reg]); | |
2230 if (spill_stack_slot_width[from_reg] > total_size) | |
2231 total_size = spill_stack_slot_width[from_reg]; | |
2232 if (MEM_ALIGN (spill_stack_slot[from_reg]) > min_align) | |
2233 min_align = MEM_ALIGN (spill_stack_slot[from_reg]); | |
2234 } | |
2235 | |
2236 /* Make a slot with that size. */ | |
2237 x = assign_stack_local (mode, total_size, | |
2238 min_align > inherent_align | |
2239 || total_size > inherent_size ? -1 : 0); | |
2240 stack_slot = x; | |
2241 | |
2242 /* Cancel the big-endian correction done in assign_stack_local. | |
2243 Get the address of the beginning of the slot. This is so we | |
2244 can do a big-endian correction unconditionally below. */ | |
2245 if (BYTES_BIG_ENDIAN) | |
2246 { | |
2247 adjust = GET_MODE_SIZE (mode) - total_size; | |
2248 if (adjust) | |
2249 stack_slot | |
2250 = adjust_address_nv (x, mode_for_size (total_size | |
2251 * BITS_PER_UNIT, | |
2252 MODE_INT, 1), | |
2253 adjust); | |
2254 } | |
2255 | |
2256 spill_stack_slot[from_reg] = stack_slot; | |
2257 spill_stack_slot_width[from_reg] = total_size; | |
2258 } | |
2259 | |
2260 /* On a big endian machine, the "address" of the slot | |
2261 is the address of the low part that fits its inherent mode. */ | |
2262 if (BYTES_BIG_ENDIAN && inherent_size < total_size) | |
2263 adjust += (total_size - inherent_size); | |
2264 | |
2265 /* If we have any adjustment to make, or if the stack slot is the | |
2266 wrong mode, make a new stack slot. */ | |
2267 x = adjust_address_nv (x, GET_MODE (regno_reg_rtx[i]), adjust); | |
2268 | |
2269 /* Set all of the memory attributes as appropriate for a spill. */ | |
2270 set_mem_attrs_for_spill (x); | |
2271 | |
2272 /* Save the stack slot for later. */ | |
2273 reg_equiv_memory_loc[i] = x; | |
2274 } | |
2275 } | |
2276 | |
2277 /* Mark the slots in regs_ever_live for the hard regs used by | |
2278 pseudo-reg number REGNO, accessed in MODE. */ | |
2279 | |
2280 static void | |
2281 mark_home_live_1 (int regno, enum machine_mode mode) | |
2282 { | |
2283 int i, lim; | |
2284 | |
2285 i = reg_renumber[regno]; | |
2286 if (i < 0) | |
2287 return; | |
2288 lim = end_hard_regno (mode, i); | |
2289 while (i < lim) | |
2290 df_set_regs_ever_live(i++, true); | |
2291 } | |
2292 | |
2293 /* Mark the slots in regs_ever_live for the hard regs | |
2294 used by pseudo-reg number REGNO. */ | |
2295 | |
2296 void | |
2297 mark_home_live (int regno) | |
2298 { | |
2299 if (reg_renumber[regno] >= 0) | |
2300 mark_home_live_1 (regno, PSEUDO_REGNO_MODE (regno)); | |
2301 } | |
2302 | |
2303 /* This function handles the tracking of elimination offsets around branches. | |
2304 | |
2305 X is a piece of RTL being scanned. | |
2306 | |
2307 INSN is the insn that it came from, if any. | |
2308 | |
2309 INITIAL_P is nonzero if we are to set the offset to be the initial | |
2310 offset and zero if we are setting the offset of the label to be the | |
2311 current offset. */ | |
2312 | |
2313 static void | |
2314 set_label_offsets (rtx x, rtx insn, int initial_p) | |
2315 { | |
2316 enum rtx_code code = GET_CODE (x); | |
2317 rtx tem; | |
2318 unsigned int i; | |
2319 struct elim_table *p; | |
2320 | |
2321 switch (code) | |
2322 { | |
2323 case LABEL_REF: | |
2324 if (LABEL_REF_NONLOCAL_P (x)) | |
2325 return; | |
2326 | |
2327 x = XEXP (x, 0); | |
2328 | |
2329 /* ... fall through ... */ | |
2330 | |
2331 case CODE_LABEL: | |
2332 /* If we know nothing about this label, set the desired offsets. Note | |
2333 that this sets the offset at a label to be the offset before a label | |
2334 if we don't know anything about the label. This is not correct for | |
2335 the label after a BARRIER, but is the best guess we can make. If | |
2336 we guessed wrong, we will suppress an elimination that might have | |
2337 been possible had we been able to guess correctly. */ | |
2338 | |
2339 if (! offsets_known_at[CODE_LABEL_NUMBER (x) - first_label_num]) | |
2340 { | |
2341 for (i = 0; i < NUM_ELIMINABLE_REGS; i++) | |
2342 offsets_at[CODE_LABEL_NUMBER (x) - first_label_num][i] | |
2343 = (initial_p ? reg_eliminate[i].initial_offset | |
2344 : reg_eliminate[i].offset); | |
2345 offsets_known_at[CODE_LABEL_NUMBER (x) - first_label_num] = 1; | |
2346 } | |
2347 | |
2348 /* Otherwise, if this is the definition of a label and it is | |
2349 preceded by a BARRIER, set our offsets to the known offset of | |
2350 that label. */ | |
2351 | |
2352 else if (x == insn | |
2353 && (tem = prev_nonnote_insn (insn)) != 0 | |
2354 && BARRIER_P (tem)) | |
2355 set_offsets_for_label (insn); | |
2356 else | |
2357 /* If neither of the above cases is true, compare each offset | |
2358 with those previously recorded and suppress any eliminations | |
2359 where the offsets disagree. */ | |
2360 | |
2361 for (i = 0; i < NUM_ELIMINABLE_REGS; i++) | |
2362 if (offsets_at[CODE_LABEL_NUMBER (x) - first_label_num][i] | |
2363 != (initial_p ? reg_eliminate[i].initial_offset | |
2364 : reg_eliminate[i].offset)) | |
2365 reg_eliminate[i].can_eliminate = 0; | |
2366 | |
2367 return; | |
2368 | |
2369 case JUMP_INSN: | |
2370 set_label_offsets (PATTERN (insn), insn, initial_p); | |
2371 | |
2372 /* ... fall through ... */ | |
2373 | |
2374 case INSN: | |
2375 case CALL_INSN: | |
2376 /* Any labels mentioned in REG_LABEL_OPERAND notes can be branched | |
2377 to indirectly and hence must have all eliminations at their | |
2378 initial offsets. */ | |
2379 for (tem = REG_NOTES (x); tem; tem = XEXP (tem, 1)) | |
2380 if (REG_NOTE_KIND (tem) == REG_LABEL_OPERAND) | |
2381 set_label_offsets (XEXP (tem, 0), insn, 1); | |
2382 return; | |
2383 | |
2384 case PARALLEL: | |
2385 case ADDR_VEC: | |
2386 case ADDR_DIFF_VEC: | |
2387 /* Each of the labels in the parallel or address vector must be | |
2388 at their initial offsets. We want the first field for PARALLEL | |
2389 and ADDR_VEC and the second field for ADDR_DIFF_VEC. */ | |
2390 | |
2391 for (i = 0; i < (unsigned) XVECLEN (x, code == ADDR_DIFF_VEC); i++) | |
2392 set_label_offsets (XVECEXP (x, code == ADDR_DIFF_VEC, i), | |
2393 insn, initial_p); | |
2394 return; | |
2395 | |
2396 case SET: | |
2397 /* We only care about setting PC. If the source is not RETURN, | |
2398 IF_THEN_ELSE, or a label, disable any eliminations not at | |
2399 their initial offsets. Similarly if any arm of the IF_THEN_ELSE | |
2400 isn't one of those possibilities. For branches to a label, | |
2401 call ourselves recursively. | |
2402 | |
2403 Note that this can disable elimination unnecessarily when we have | |
2404 a non-local goto since it will look like a non-constant jump to | |
2405 someplace in the current function. This isn't a significant | |
2406 problem since such jumps will normally be when all elimination | |
2407 pairs are back to their initial offsets. */ | |
2408 | |
2409 if (SET_DEST (x) != pc_rtx) | |
2410 return; | |
2411 | |
2412 switch (GET_CODE (SET_SRC (x))) | |
2413 { | |
2414 case PC: | |
2415 case RETURN: | |
2416 return; | |
2417 | |
2418 case LABEL_REF: | |
2419 set_label_offsets (SET_SRC (x), insn, initial_p); | |
2420 return; | |
2421 | |
2422 case IF_THEN_ELSE: | |
2423 tem = XEXP (SET_SRC (x), 1); | |
2424 if (GET_CODE (tem) == LABEL_REF) | |
2425 set_label_offsets (XEXP (tem, 0), insn, initial_p); | |
2426 else if (GET_CODE (tem) != PC && GET_CODE (tem) != RETURN) | |
2427 break; | |
2428 | |
2429 tem = XEXP (SET_SRC (x), 2); | |
2430 if (GET_CODE (tem) == LABEL_REF) | |
2431 set_label_offsets (XEXP (tem, 0), insn, initial_p); | |
2432 else if (GET_CODE (tem) != PC && GET_CODE (tem) != RETURN) | |
2433 break; | |
2434 return; | |
2435 | |
2436 default: | |
2437 break; | |
2438 } | |
2439 | |
2440 /* If we reach here, all eliminations must be at their initial | |
2441 offset because we are doing a jump to a variable address. */ | |
2442 for (p = reg_eliminate; p < ®_eliminate[NUM_ELIMINABLE_REGS]; p++) | |
2443 if (p->offset != p->initial_offset) | |
2444 p->can_eliminate = 0; | |
2445 break; | |
2446 | |
2447 default: | |
2448 break; | |
2449 } | |
2450 } | |
2451 | |
2452 /* Scan X and replace any eliminable registers (such as fp) with a | |
2453 replacement (such as sp), plus an offset. | |
2454 | |
2455 MEM_MODE is the mode of an enclosing MEM. We need this to know how | |
2456 much to adjust a register for, e.g., PRE_DEC. Also, if we are inside a | |
2457 MEM, we are allowed to replace a sum of a register and the constant zero | |
2458 with the register, which we cannot do outside a MEM. In addition, we need | |
2459 to record the fact that a register is referenced outside a MEM. | |
2460 | |
2461 If INSN is an insn, it is the insn containing X. If we replace a REG | |
2462 in a SET_DEST with an equivalent MEM and INSN is nonzero, write a | |
2463 CLOBBER of the pseudo after INSN so find_equiv_regs will know that | |
2464 the REG is being modified. | |
2465 | |
2466 Alternatively, INSN may be a note (an EXPR_LIST or INSN_LIST). | |
2467 That's used when we eliminate in expressions stored in notes. | |
2468 This means, do not set ref_outside_mem even if the reference | |
2469 is outside of MEMs. | |
2470 | |
2471 REG_EQUIV_MEM and REG_EQUIV_ADDRESS contain address that have had | |
2472 replacements done assuming all offsets are at their initial values. If | |
2473 they are not, or if REG_EQUIV_ADDRESS is nonzero for a pseudo we | |
2474 encounter, return the actual location so that find_reloads will do | |
2475 the proper thing. */ | |
2476 | |
2477 static rtx | |
2478 eliminate_regs_1 (rtx x, enum machine_mode mem_mode, rtx insn, | |
2479 bool may_use_invariant) | |
2480 { | |
2481 enum rtx_code code = GET_CODE (x); | |
2482 struct elim_table *ep; | |
2483 int regno; | |
2484 rtx new_rtx; | |
2485 int i, j; | |
2486 const char *fmt; | |
2487 int copied = 0; | |
2488 | |
2489 if (! current_function_decl) | |
2490 return x; | |
2491 | |
2492 switch (code) | |
2493 { | |
2494 case CONST_INT: | |
2495 case CONST_DOUBLE: | |
2496 case CONST_FIXED: | |
2497 case CONST_VECTOR: | |
2498 case CONST: | |
2499 case SYMBOL_REF: | |
2500 case CODE_LABEL: | |
2501 case PC: | |
2502 case CC0: | |
2503 case ASM_INPUT: | |
2504 case ADDR_VEC: | |
2505 case ADDR_DIFF_VEC: | |
2506 case RETURN: | |
2507 return x; | |
2508 | |
2509 case REG: | |
2510 regno = REGNO (x); | |
2511 | |
2512 /* First handle the case where we encounter a bare register that | |
2513 is eliminable. Replace it with a PLUS. */ | |
2514 if (regno < FIRST_PSEUDO_REGISTER) | |
2515 { | |
2516 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; | |
2517 ep++) | |
2518 if (ep->from_rtx == x && ep->can_eliminate) | |
2519 return plus_constant (ep->to_rtx, ep->previous_offset); | |
2520 | |
2521 } | |
2522 else if (reg_renumber && reg_renumber[regno] < 0 | |
2523 && reg_equiv_invariant && reg_equiv_invariant[regno]) | |
2524 { | |
2525 if (may_use_invariant) | |
2526 return eliminate_regs_1 (copy_rtx (reg_equiv_invariant[regno]), | |
2527 mem_mode, insn, true); | |
2528 /* There exists at least one use of REGNO that cannot be | |
2529 eliminated. Prevent the defining insn from being deleted. */ | |
2530 reg_equiv_init[regno] = NULL_RTX; | |
2531 alter_reg (regno, -1, true); | |
2532 } | |
2533 return x; | |
2534 | |
2535 /* You might think handling MINUS in a manner similar to PLUS is a | |
2536 good idea. It is not. It has been tried multiple times and every | |
2537 time the change has had to have been reverted. | |
2538 | |
2539 Other parts of reload know a PLUS is special (gen_reload for example) | |
2540 and require special code to handle code a reloaded PLUS operand. | |
2541 | |
2542 Also consider backends where the flags register is clobbered by a | |
2543 MINUS, but we can emit a PLUS that does not clobber flags (IA-32, | |
2544 lea instruction comes to mind). If we try to reload a MINUS, we | |
2545 may kill the flags register that was holding a useful value. | |
2546 | |
2547 So, please before trying to handle MINUS, consider reload as a | |
2548 whole instead of this little section as well as the backend issues. */ | |
2549 case PLUS: | |
2550 /* If this is the sum of an eliminable register and a constant, rework | |
2551 the sum. */ | |
2552 if (REG_P (XEXP (x, 0)) | |
2553 && REGNO (XEXP (x, 0)) < FIRST_PSEUDO_REGISTER | |
2554 && CONSTANT_P (XEXP (x, 1))) | |
2555 { | |
2556 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; | |
2557 ep++) | |
2558 if (ep->from_rtx == XEXP (x, 0) && ep->can_eliminate) | |
2559 { | |
2560 /* The only time we want to replace a PLUS with a REG (this | |
2561 occurs when the constant operand of the PLUS is the negative | |
2562 of the offset) is when we are inside a MEM. We won't want | |
2563 to do so at other times because that would change the | |
2564 structure of the insn in a way that reload can't handle. | |
2565 We special-case the commonest situation in | |
2566 eliminate_regs_in_insn, so just replace a PLUS with a | |
2567 PLUS here, unless inside a MEM. */ | |
2568 if (mem_mode != 0 && GET_CODE (XEXP (x, 1)) == CONST_INT | |
2569 && INTVAL (XEXP (x, 1)) == - ep->previous_offset) | |
2570 return ep->to_rtx; | |
2571 else | |
2572 return gen_rtx_PLUS (Pmode, ep->to_rtx, | |
2573 plus_constant (XEXP (x, 1), | |
2574 ep->previous_offset)); | |
2575 } | |
2576 | |
2577 /* If the register is not eliminable, we are done since the other | |
2578 operand is a constant. */ | |
2579 return x; | |
2580 } | |
2581 | |
2582 /* If this is part of an address, we want to bring any constant to the | |
2583 outermost PLUS. We will do this by doing register replacement in | |
2584 our operands and seeing if a constant shows up in one of them. | |
2585 | |
2586 Note that there is no risk of modifying the structure of the insn, | |
2587 since we only get called for its operands, thus we are either | |
2588 modifying the address inside a MEM, or something like an address | |
2589 operand of a load-address insn. */ | |
2590 | |
2591 { | |
2592 rtx new0 = eliminate_regs_1 (XEXP (x, 0), mem_mode, insn, true); | |
2593 rtx new1 = eliminate_regs_1 (XEXP (x, 1), mem_mode, insn, true); | |
2594 | |
2595 if (reg_renumber && (new0 != XEXP (x, 0) || new1 != XEXP (x, 1))) | |
2596 { | |
2597 /* If one side is a PLUS and the other side is a pseudo that | |
2598 didn't get a hard register but has a reg_equiv_constant, | |
2599 we must replace the constant here since it may no longer | |
2600 be in the position of any operand. */ | |
2601 if (GET_CODE (new0) == PLUS && REG_P (new1) | |
2602 && REGNO (new1) >= FIRST_PSEUDO_REGISTER | |
2603 && reg_renumber[REGNO (new1)] < 0 | |
2604 && reg_equiv_constant != 0 | |
2605 && reg_equiv_constant[REGNO (new1)] != 0) | |
2606 new1 = reg_equiv_constant[REGNO (new1)]; | |
2607 else if (GET_CODE (new1) == PLUS && REG_P (new0) | |
2608 && REGNO (new0) >= FIRST_PSEUDO_REGISTER | |
2609 && reg_renumber[REGNO (new0)] < 0 | |
2610 && reg_equiv_constant[REGNO (new0)] != 0) | |
2611 new0 = reg_equiv_constant[REGNO (new0)]; | |
2612 | |
2613 new_rtx = form_sum (new0, new1); | |
2614 | |
2615 /* As above, if we are not inside a MEM we do not want to | |
2616 turn a PLUS into something else. We might try to do so here | |
2617 for an addition of 0 if we aren't optimizing. */ | |
2618 if (! mem_mode && GET_CODE (new_rtx) != PLUS) | |
2619 return gen_rtx_PLUS (GET_MODE (x), new_rtx, const0_rtx); | |
2620 else | |
2621 return new_rtx; | |
2622 } | |
2623 } | |
2624 return x; | |
2625 | |
2626 case MULT: | |
2627 /* If this is the product of an eliminable register and a | |
2628 constant, apply the distribute law and move the constant out | |
2629 so that we have (plus (mult ..) ..). This is needed in order | |
2630 to keep load-address insns valid. This case is pathological. | |
2631 We ignore the possibility of overflow here. */ | |
2632 if (REG_P (XEXP (x, 0)) | |
2633 && REGNO (XEXP (x, 0)) < FIRST_PSEUDO_REGISTER | |
2634 && GET_CODE (XEXP (x, 1)) == CONST_INT) | |
2635 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; | |
2636 ep++) | |
2637 if (ep->from_rtx == XEXP (x, 0) && ep->can_eliminate) | |
2638 { | |
2639 if (! mem_mode | |
2640 /* Refs inside notes don't count for this purpose. */ | |
2641 && ! (insn != 0 && (GET_CODE (insn) == EXPR_LIST | |
2642 || GET_CODE (insn) == INSN_LIST))) | |
2643 ep->ref_outside_mem = 1; | |
2644 | |
2645 return | |
2646 plus_constant (gen_rtx_MULT (Pmode, ep->to_rtx, XEXP (x, 1)), | |
2647 ep->previous_offset * INTVAL (XEXP (x, 1))); | |
2648 } | |
2649 | |
2650 /* ... fall through ... */ | |
2651 | |
2652 case CALL: | |
2653 case COMPARE: | |
2654 /* See comments before PLUS about handling MINUS. */ | |
2655 case MINUS: | |
2656 case DIV: case UDIV: | |
2657 case MOD: case UMOD: | |
2658 case AND: case IOR: case XOR: | |
2659 case ROTATERT: case ROTATE: | |
2660 case ASHIFTRT: case LSHIFTRT: case ASHIFT: | |
2661 case NE: case EQ: | |
2662 case GE: case GT: case GEU: case GTU: | |
2663 case LE: case LT: case LEU: case LTU: | |
2664 { | |
2665 rtx new0 = eliminate_regs_1 (XEXP (x, 0), mem_mode, insn, false); | |
2666 rtx new1 = XEXP (x, 1) | |
2667 ? eliminate_regs_1 (XEXP (x, 1), mem_mode, insn, false) : 0; | |
2668 | |
2669 if (new0 != XEXP (x, 0) || new1 != XEXP (x, 1)) | |
2670 return gen_rtx_fmt_ee (code, GET_MODE (x), new0, new1); | |
2671 } | |
2672 return x; | |
2673 | |
2674 case EXPR_LIST: | |
2675 /* If we have something in XEXP (x, 0), the usual case, eliminate it. */ | |
2676 if (XEXP (x, 0)) | |
2677 { | |
2678 new_rtx = eliminate_regs_1 (XEXP (x, 0), mem_mode, insn, true); | |
2679 if (new_rtx != XEXP (x, 0)) | |
2680 { | |
2681 /* If this is a REG_DEAD note, it is not valid anymore. | |
2682 Using the eliminated version could result in creating a | |
2683 REG_DEAD note for the stack or frame pointer. */ | |
2684 if (REG_NOTE_KIND (x) == REG_DEAD) | |
2685 return (XEXP (x, 1) | |
2686 ? eliminate_regs_1 (XEXP (x, 1), mem_mode, insn, true) | |
2687 : NULL_RTX); | |
2688 | |
2689 x = gen_rtx_EXPR_LIST (REG_NOTE_KIND (x), new_rtx, XEXP (x, 1)); | |
2690 } | |
2691 } | |
2692 | |
2693 /* ... fall through ... */ | |
2694 | |
2695 case INSN_LIST: | |
2696 /* Now do eliminations in the rest of the chain. If this was | |
2697 an EXPR_LIST, this might result in allocating more memory than is | |
2698 strictly needed, but it simplifies the code. */ | |
2699 if (XEXP (x, 1)) | |
2700 { | |
2701 new_rtx = eliminate_regs_1 (XEXP (x, 1), mem_mode, insn, true); | |
2702 if (new_rtx != XEXP (x, 1)) | |
2703 return | |
2704 gen_rtx_fmt_ee (GET_CODE (x), GET_MODE (x), XEXP (x, 0), new_rtx); | |
2705 } | |
2706 return x; | |
2707 | |
2708 case PRE_INC: | |
2709 case POST_INC: | |
2710 case PRE_DEC: | |
2711 case POST_DEC: | |
2712 /* We do not support elimination of a register that is modified. | |
2713 elimination_effects has already make sure that this does not | |
2714 happen. */ | |
2715 return x; | |
2716 | |
2717 case PRE_MODIFY: | |
2718 case POST_MODIFY: | |
2719 /* We do not support elimination of a register that is modified. | |
2720 elimination_effects has already make sure that this does not | |
2721 happen. The only remaining case we need to consider here is | |
2722 that the increment value may be an eliminable register. */ | |
2723 if (GET_CODE (XEXP (x, 1)) == PLUS | |
2724 && XEXP (XEXP (x, 1), 0) == XEXP (x, 0)) | |
2725 { | |
2726 rtx new_rtx = eliminate_regs_1 (XEXP (XEXP (x, 1), 1), mem_mode, | |
2727 insn, true); | |
2728 | |
2729 if (new_rtx != XEXP (XEXP (x, 1), 1)) | |
2730 return gen_rtx_fmt_ee (code, GET_MODE (x), XEXP (x, 0), | |
2731 gen_rtx_PLUS (GET_MODE (x), | |
2732 XEXP (x, 0), new_rtx)); | |
2733 } | |
2734 return x; | |
2735 | |
2736 case STRICT_LOW_PART: | |
2737 case NEG: case NOT: | |
2738 case SIGN_EXTEND: case ZERO_EXTEND: | |
2739 case TRUNCATE: case FLOAT_EXTEND: case FLOAT_TRUNCATE: | |
2740 case FLOAT: case FIX: | |
2741 case UNSIGNED_FIX: case UNSIGNED_FLOAT: | |
2742 case ABS: | |
2743 case SQRT: | |
2744 case FFS: | |
2745 case CLZ: | |
2746 case CTZ: | |
2747 case POPCOUNT: | |
2748 case PARITY: | |
2749 case BSWAP: | |
2750 new_rtx = eliminate_regs_1 (XEXP (x, 0), mem_mode, insn, false); | |
2751 if (new_rtx != XEXP (x, 0)) | |
2752 return gen_rtx_fmt_e (code, GET_MODE (x), new_rtx); | |
2753 return x; | |
2754 | |
2755 case SUBREG: | |
2756 /* Similar to above processing, but preserve SUBREG_BYTE. | |
2757 Convert (subreg (mem)) to (mem) if not paradoxical. | |
2758 Also, if we have a non-paradoxical (subreg (pseudo)) and the | |
2759 pseudo didn't get a hard reg, we must replace this with the | |
2760 eliminated version of the memory location because push_reload | |
2761 may do the replacement in certain circumstances. */ | |
2762 if (REG_P (SUBREG_REG (x)) | |
2763 && (GET_MODE_SIZE (GET_MODE (x)) | |
2764 <= GET_MODE_SIZE (GET_MODE (SUBREG_REG (x)))) | |
2765 && reg_equiv_memory_loc != 0 | |
2766 && reg_equiv_memory_loc[REGNO (SUBREG_REG (x))] != 0) | |
2767 { | |
2768 new_rtx = SUBREG_REG (x); | |
2769 } | |
2770 else | |
2771 new_rtx = eliminate_regs_1 (SUBREG_REG (x), mem_mode, insn, false); | |
2772 | |
2773 if (new_rtx != SUBREG_REG (x)) | |
2774 { | |
2775 int x_size = GET_MODE_SIZE (GET_MODE (x)); | |
2776 int new_size = GET_MODE_SIZE (GET_MODE (new_rtx)); | |
2777 | |
2778 if (MEM_P (new_rtx) | |
2779 && ((x_size < new_size | |
2780 #ifdef WORD_REGISTER_OPERATIONS | |
2781 /* On these machines, combine can create rtl of the form | |
2782 (set (subreg:m1 (reg:m2 R) 0) ...) | |
2783 where m1 < m2, and expects something interesting to | |
2784 happen to the entire word. Moreover, it will use the | |
2785 (reg:m2 R) later, expecting all bits to be preserved. | |
2786 So if the number of words is the same, preserve the | |
2787 subreg so that push_reload can see it. */ | |
2788 && ! ((x_size - 1) / UNITS_PER_WORD | |
2789 == (new_size -1 ) / UNITS_PER_WORD) | |
2790 #endif | |
2791 ) | |
2792 || x_size == new_size) | |
2793 ) | |
2794 return adjust_address_nv (new_rtx, GET_MODE (x), SUBREG_BYTE (x)); | |
2795 else | |
2796 return gen_rtx_SUBREG (GET_MODE (x), new_rtx, SUBREG_BYTE (x)); | |
2797 } | |
2798 | |
2799 return x; | |
2800 | |
2801 case MEM: | |
2802 /* Our only special processing is to pass the mode of the MEM to our | |
2803 recursive call and copy the flags. While we are here, handle this | |
2804 case more efficiently. */ | |
2805 return | |
2806 replace_equiv_address_nv (x, | |
2807 eliminate_regs_1 (XEXP (x, 0), GET_MODE (x), | |
2808 insn, true)); | |
2809 | |
2810 case USE: | |
2811 /* Handle insn_list USE that a call to a pure function may generate. */ | |
2812 new_rtx = eliminate_regs_1 (XEXP (x, 0), 0, insn, false); | |
2813 if (new_rtx != XEXP (x, 0)) | |
2814 return gen_rtx_USE (GET_MODE (x), new_rtx); | |
2815 return x; | |
2816 | |
2817 case CLOBBER: | |
2818 case ASM_OPERANDS: | |
2819 case SET: | |
2820 gcc_unreachable (); | |
2821 | |
2822 default: | |
2823 break; | |
2824 } | |
2825 | |
2826 /* Process each of our operands recursively. If any have changed, make a | |
2827 copy of the rtx. */ | |
2828 fmt = GET_RTX_FORMAT (code); | |
2829 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++) | |
2830 { | |
2831 if (*fmt == 'e') | |
2832 { | |
2833 new_rtx = eliminate_regs_1 (XEXP (x, i), mem_mode, insn, false); | |
2834 if (new_rtx != XEXP (x, i) && ! copied) | |
2835 { | |
2836 x = shallow_copy_rtx (x); | |
2837 copied = 1; | |
2838 } | |
2839 XEXP (x, i) = new_rtx; | |
2840 } | |
2841 else if (*fmt == 'E') | |
2842 { | |
2843 int copied_vec = 0; | |
2844 for (j = 0; j < XVECLEN (x, i); j++) | |
2845 { | |
2846 new_rtx = eliminate_regs_1 (XVECEXP (x, i, j), mem_mode, insn, false); | |
2847 if (new_rtx != XVECEXP (x, i, j) && ! copied_vec) | |
2848 { | |
2849 rtvec new_v = gen_rtvec_v (XVECLEN (x, i), | |
2850 XVEC (x, i)->elem); | |
2851 if (! copied) | |
2852 { | |
2853 x = shallow_copy_rtx (x); | |
2854 copied = 1; | |
2855 } | |
2856 XVEC (x, i) = new_v; | |
2857 copied_vec = 1; | |
2858 } | |
2859 XVECEXP (x, i, j) = new_rtx; | |
2860 } | |
2861 } | |
2862 } | |
2863 | |
2864 return x; | |
2865 } | |
2866 | |
2867 rtx | |
2868 eliminate_regs (rtx x, enum machine_mode mem_mode, rtx insn) | |
2869 { | |
2870 return eliminate_regs_1 (x, mem_mode, insn, false); | |
2871 } | |
2872 | |
2873 /* Scan rtx X for modifications of elimination target registers. Update | |
2874 the table of eliminables to reflect the changed state. MEM_MODE is | |
2875 the mode of an enclosing MEM rtx, or VOIDmode if not within a MEM. */ | |
2876 | |
2877 static void | |
2878 elimination_effects (rtx x, enum machine_mode mem_mode) | |
2879 { | |
2880 enum rtx_code code = GET_CODE (x); | |
2881 struct elim_table *ep; | |
2882 int regno; | |
2883 int i, j; | |
2884 const char *fmt; | |
2885 | |
2886 switch (code) | |
2887 { | |
2888 case CONST_INT: | |
2889 case CONST_DOUBLE: | |
2890 case CONST_FIXED: | |
2891 case CONST_VECTOR: | |
2892 case CONST: | |
2893 case SYMBOL_REF: | |
2894 case CODE_LABEL: | |
2895 case PC: | |
2896 case CC0: | |
2897 case ASM_INPUT: | |
2898 case ADDR_VEC: | |
2899 case ADDR_DIFF_VEC: | |
2900 case RETURN: | |
2901 return; | |
2902 | |
2903 case REG: | |
2904 regno = REGNO (x); | |
2905 | |
2906 /* First handle the case where we encounter a bare register that | |
2907 is eliminable. Replace it with a PLUS. */ | |
2908 if (regno < FIRST_PSEUDO_REGISTER) | |
2909 { | |
2910 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; | |
2911 ep++) | |
2912 if (ep->from_rtx == x && ep->can_eliminate) | |
2913 { | |
2914 if (! mem_mode) | |
2915 ep->ref_outside_mem = 1; | |
2916 return; | |
2917 } | |
2918 | |
2919 } | |
2920 else if (reg_renumber[regno] < 0 && reg_equiv_constant | |
2921 && reg_equiv_constant[regno] | |
2922 && ! function_invariant_p (reg_equiv_constant[regno])) | |
2923 elimination_effects (reg_equiv_constant[regno], mem_mode); | |
2924 return; | |
2925 | |
2926 case PRE_INC: | |
2927 case POST_INC: | |
2928 case PRE_DEC: | |
2929 case POST_DEC: | |
2930 case POST_MODIFY: | |
2931 case PRE_MODIFY: | |
2932 /* If we modify the source of an elimination rule, disable it. */ | |
2933 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++) | |
2934 if (ep->from_rtx == XEXP (x, 0)) | |
2935 ep->can_eliminate = 0; | |
2936 | |
2937 /* If we modify the target of an elimination rule by adding a constant, | |
2938 update its offset. If we modify the target in any other way, we'll | |
2939 have to disable the rule as well. */ | |
2940 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++) | |
2941 if (ep->to_rtx == XEXP (x, 0)) | |
2942 { | |
2943 int size = GET_MODE_SIZE (mem_mode); | |
2944 | |
2945 /* If more bytes than MEM_MODE are pushed, account for them. */ | |
2946 #ifdef PUSH_ROUNDING | |
2947 if (ep->to_rtx == stack_pointer_rtx) | |
2948 size = PUSH_ROUNDING (size); | |
2949 #endif | |
2950 if (code == PRE_DEC || code == POST_DEC) | |
2951 ep->offset += size; | |
2952 else if (code == PRE_INC || code == POST_INC) | |
2953 ep->offset -= size; | |
2954 else if (code == PRE_MODIFY || code == POST_MODIFY) | |
2955 { | |
2956 if (GET_CODE (XEXP (x, 1)) == PLUS | |
2957 && XEXP (x, 0) == XEXP (XEXP (x, 1), 0) | |
2958 && CONST_INT_P (XEXP (XEXP (x, 1), 1))) | |
2959 ep->offset -= INTVAL (XEXP (XEXP (x, 1), 1)); | |
2960 else | |
2961 ep->can_eliminate = 0; | |
2962 } | |
2963 } | |
2964 | |
2965 /* These two aren't unary operators. */ | |
2966 if (code == POST_MODIFY || code == PRE_MODIFY) | |
2967 break; | |
2968 | |
2969 /* Fall through to generic unary operation case. */ | |
2970 case STRICT_LOW_PART: | |
2971 case NEG: case NOT: | |
2972 case SIGN_EXTEND: case ZERO_EXTEND: | |
2973 case TRUNCATE: case FLOAT_EXTEND: case FLOAT_TRUNCATE: | |
2974 case FLOAT: case FIX: | |
2975 case UNSIGNED_FIX: case UNSIGNED_FLOAT: | |
2976 case ABS: | |
2977 case SQRT: | |
2978 case FFS: | |
2979 case CLZ: | |
2980 case CTZ: | |
2981 case POPCOUNT: | |
2982 case PARITY: | |
2983 case BSWAP: | |
2984 elimination_effects (XEXP (x, 0), mem_mode); | |
2985 return; | |
2986 | |
2987 case SUBREG: | |
2988 if (REG_P (SUBREG_REG (x)) | |
2989 && (GET_MODE_SIZE (GET_MODE (x)) | |
2990 <= GET_MODE_SIZE (GET_MODE (SUBREG_REG (x)))) | |
2991 && reg_equiv_memory_loc != 0 | |
2992 && reg_equiv_memory_loc[REGNO (SUBREG_REG (x))] != 0) | |
2993 return; | |
2994 | |
2995 elimination_effects (SUBREG_REG (x), mem_mode); | |
2996 return; | |
2997 | |
2998 case USE: | |
2999 /* If using a register that is the source of an eliminate we still | |
3000 think can be performed, note it cannot be performed since we don't | |
3001 know how this register is used. */ | |
3002 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++) | |
3003 if (ep->from_rtx == XEXP (x, 0)) | |
3004 ep->can_eliminate = 0; | |
3005 | |
3006 elimination_effects (XEXP (x, 0), mem_mode); | |
3007 return; | |
3008 | |
3009 case CLOBBER: | |
3010 /* If clobbering a register that is the replacement register for an | |
3011 elimination we still think can be performed, note that it cannot | |
3012 be performed. Otherwise, we need not be concerned about it. */ | |
3013 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++) | |
3014 if (ep->to_rtx == XEXP (x, 0)) | |
3015 ep->can_eliminate = 0; | |
3016 | |
3017 elimination_effects (XEXP (x, 0), mem_mode); | |
3018 return; | |
3019 | |
3020 case SET: | |
3021 /* Check for setting a register that we know about. */ | |
3022 if (REG_P (SET_DEST (x))) | |
3023 { | |
3024 /* See if this is setting the replacement register for an | |
3025 elimination. | |
3026 | |
3027 If DEST is the hard frame pointer, we do nothing because we | |
3028 assume that all assignments to the frame pointer are for | |
3029 non-local gotos and are being done at a time when they are valid | |
3030 and do not disturb anything else. Some machines want to | |
3031 eliminate a fake argument pointer (or even a fake frame pointer) | |
3032 with either the real frame or the stack pointer. Assignments to | |
3033 the hard frame pointer must not prevent this elimination. */ | |
3034 | |
3035 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; | |
3036 ep++) | |
3037 if (ep->to_rtx == SET_DEST (x) | |
3038 && SET_DEST (x) != hard_frame_pointer_rtx) | |
3039 { | |
3040 /* If it is being incremented, adjust the offset. Otherwise, | |
3041 this elimination can't be done. */ | |
3042 rtx src = SET_SRC (x); | |
3043 | |
3044 if (GET_CODE (src) == PLUS | |
3045 && XEXP (src, 0) == SET_DEST (x) | |
3046 && GET_CODE (XEXP (src, 1)) == CONST_INT) | |
3047 ep->offset -= INTVAL (XEXP (src, 1)); | |
3048 else | |
3049 ep->can_eliminate = 0; | |
3050 } | |
3051 } | |
3052 | |
3053 elimination_effects (SET_DEST (x), 0); | |
3054 elimination_effects (SET_SRC (x), 0); | |
3055 return; | |
3056 | |
3057 case MEM: | |
3058 /* Our only special processing is to pass the mode of the MEM to our | |
3059 recursive call. */ | |
3060 elimination_effects (XEXP (x, 0), GET_MODE (x)); | |
3061 return; | |
3062 | |
3063 default: | |
3064 break; | |
3065 } | |
3066 | |
3067 fmt = GET_RTX_FORMAT (code); | |
3068 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++) | |
3069 { | |
3070 if (*fmt == 'e') | |
3071 elimination_effects (XEXP (x, i), mem_mode); | |
3072 else if (*fmt == 'E') | |
3073 for (j = 0; j < XVECLEN (x, i); j++) | |
3074 elimination_effects (XVECEXP (x, i, j), mem_mode); | |
3075 } | |
3076 } | |
3077 | |
3078 /* Descend through rtx X and verify that no references to eliminable registers | |
3079 remain. If any do remain, mark the involved register as not | |
3080 eliminable. */ | |
3081 | |
3082 static void | |
3083 check_eliminable_occurrences (rtx x) | |
3084 { | |
3085 const char *fmt; | |
3086 int i; | |
3087 enum rtx_code code; | |
3088 | |
3089 if (x == 0) | |
3090 return; | |
3091 | |
3092 code = GET_CODE (x); | |
3093 | |
3094 if (code == REG && REGNO (x) < FIRST_PSEUDO_REGISTER) | |
3095 { | |
3096 struct elim_table *ep; | |
3097 | |
3098 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++) | |
3099 if (ep->from_rtx == x) | |
3100 ep->can_eliminate = 0; | |
3101 return; | |
3102 } | |
3103 | |
3104 fmt = GET_RTX_FORMAT (code); | |
3105 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++) | |
3106 { | |
3107 if (*fmt == 'e') | |
3108 check_eliminable_occurrences (XEXP (x, i)); | |
3109 else if (*fmt == 'E') | |
3110 { | |
3111 int j; | |
3112 for (j = 0; j < XVECLEN (x, i); j++) | |
3113 check_eliminable_occurrences (XVECEXP (x, i, j)); | |
3114 } | |
3115 } | |
3116 } | |
3117 | |
3118 /* Scan INSN and eliminate all eliminable registers in it. | |
3119 | |
3120 If REPLACE is nonzero, do the replacement destructively. Also | |
3121 delete the insn as dead it if it is setting an eliminable register. | |
3122 | |
3123 If REPLACE is zero, do all our allocations in reload_obstack. | |
3124 | |
3125 If no eliminations were done and this insn doesn't require any elimination | |
3126 processing (these are not identical conditions: it might be updating sp, | |
3127 but not referencing fp; this needs to be seen during reload_as_needed so | |
3128 that the offset between fp and sp can be taken into consideration), zero | |
3129 is returned. Otherwise, 1 is returned. */ | |
3130 | |
3131 static int | |
3132 eliminate_regs_in_insn (rtx insn, int replace) | |
3133 { | |
3134 int icode = recog_memoized (insn); | |
3135 rtx old_body = PATTERN (insn); | |
3136 int insn_is_asm = asm_noperands (old_body) >= 0; | |
3137 rtx old_set = single_set (insn); | |
3138 rtx new_body; | |
3139 int val = 0; | |
3140 int i; | |
3141 rtx substed_operand[MAX_RECOG_OPERANDS]; | |
3142 rtx orig_operand[MAX_RECOG_OPERANDS]; | |
3143 struct elim_table *ep; | |
3144 rtx plus_src, plus_cst_src; | |
3145 | |
3146 if (! insn_is_asm && icode < 0) | |
3147 { | |
3148 gcc_assert (GET_CODE (PATTERN (insn)) == USE | |
3149 || GET_CODE (PATTERN (insn)) == CLOBBER | |
3150 || GET_CODE (PATTERN (insn)) == ADDR_VEC | |
3151 || GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC | |
3152 || GET_CODE (PATTERN (insn)) == ASM_INPUT); | |
3153 return 0; | |
3154 } | |
3155 | |
3156 if (old_set != 0 && REG_P (SET_DEST (old_set)) | |
3157 && REGNO (SET_DEST (old_set)) < FIRST_PSEUDO_REGISTER) | |
3158 { | |
3159 /* Check for setting an eliminable register. */ | |
3160 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++) | |
3161 if (ep->from_rtx == SET_DEST (old_set) && ep->can_eliminate) | |
3162 { | |
3163 #if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM | |
3164 /* If this is setting the frame pointer register to the | |
3165 hardware frame pointer register and this is an elimination | |
3166 that will be done (tested above), this insn is really | |
3167 adjusting the frame pointer downward to compensate for | |
3168 the adjustment done before a nonlocal goto. */ | |
3169 if (ep->from == FRAME_POINTER_REGNUM | |
3170 && ep->to == HARD_FRAME_POINTER_REGNUM) | |
3171 { | |
3172 rtx base = SET_SRC (old_set); | |
3173 rtx base_insn = insn; | |
3174 HOST_WIDE_INT offset = 0; | |
3175 | |
3176 while (base != ep->to_rtx) | |
3177 { | |
3178 rtx prev_insn, prev_set; | |
3179 | |
3180 if (GET_CODE (base) == PLUS | |
3181 && GET_CODE (XEXP (base, 1)) == CONST_INT) | |
3182 { | |
3183 offset += INTVAL (XEXP (base, 1)); | |
3184 base = XEXP (base, 0); | |
3185 } | |
3186 else if ((prev_insn = prev_nonnote_insn (base_insn)) != 0 | |
3187 && (prev_set = single_set (prev_insn)) != 0 | |
3188 && rtx_equal_p (SET_DEST (prev_set), base)) | |
3189 { | |
3190 base = SET_SRC (prev_set); | |
3191 base_insn = prev_insn; | |
3192 } | |
3193 else | |
3194 break; | |
3195 } | |
3196 | |
3197 if (base == ep->to_rtx) | |
3198 { | |
3199 rtx src | |
3200 = plus_constant (ep->to_rtx, offset - ep->offset); | |
3201 | |
3202 new_body = old_body; | |
3203 if (! replace) | |
3204 { | |
3205 new_body = copy_insn (old_body); | |
3206 if (REG_NOTES (insn)) | |
3207 REG_NOTES (insn) = copy_insn_1 (REG_NOTES (insn)); | |
3208 } | |
3209 PATTERN (insn) = new_body; | |
3210 old_set = single_set (insn); | |
3211 | |
3212 /* First see if this insn remains valid when we | |
3213 make the change. If not, keep the INSN_CODE | |
3214 the same and let reload fit it up. */ | |
3215 validate_change (insn, &SET_SRC (old_set), src, 1); | |
3216 validate_change (insn, &SET_DEST (old_set), | |
3217 ep->to_rtx, 1); | |
3218 if (! apply_change_group ()) | |
3219 { | |
3220 SET_SRC (old_set) = src; | |
3221 SET_DEST (old_set) = ep->to_rtx; | |
3222 } | |
3223 | |
3224 val = 1; | |
3225 goto done; | |
3226 } | |
3227 } | |
3228 #endif | |
3229 | |
3230 /* In this case this insn isn't serving a useful purpose. We | |
3231 will delete it in reload_as_needed once we know that this | |
3232 elimination is, in fact, being done. | |
3233 | |
3234 If REPLACE isn't set, we can't delete this insn, but needn't | |
3235 process it since it won't be used unless something changes. */ | |
3236 if (replace) | |
3237 { | |
3238 delete_dead_insn (insn); | |
3239 return 1; | |
3240 } | |
3241 val = 1; | |
3242 goto done; | |
3243 } | |
3244 } | |
3245 | |
3246 /* We allow one special case which happens to work on all machines we | |
3247 currently support: a single set with the source or a REG_EQUAL | |
3248 note being a PLUS of an eliminable register and a constant. */ | |
3249 plus_src = plus_cst_src = 0; | |
3250 if (old_set && REG_P (SET_DEST (old_set))) | |
3251 { | |
3252 if (GET_CODE (SET_SRC (old_set)) == PLUS) | |
3253 plus_src = SET_SRC (old_set); | |
3254 /* First see if the source is of the form (plus (...) CST). */ | |
3255 if (plus_src | |
3256 && GET_CODE (XEXP (plus_src, 1)) == CONST_INT) | |
3257 plus_cst_src = plus_src; | |
3258 else if (REG_P (SET_SRC (old_set)) | |
3259 || plus_src) | |
3260 { | |
3261 /* Otherwise, see if we have a REG_EQUAL note of the form | |
3262 (plus (...) CST). */ | |
3263 rtx links; | |
3264 for (links = REG_NOTES (insn); links; links = XEXP (links, 1)) | |
3265 { | |
3266 if ((REG_NOTE_KIND (links) == REG_EQUAL | |
3267 || REG_NOTE_KIND (links) == REG_EQUIV) | |
3268 && GET_CODE (XEXP (links, 0)) == PLUS | |
3269 && GET_CODE (XEXP (XEXP (links, 0), 1)) == CONST_INT) | |
3270 { | |
3271 plus_cst_src = XEXP (links, 0); | |
3272 break; | |
3273 } | |
3274 } | |
3275 } | |
3276 | |
3277 /* Check that the first operand of the PLUS is a hard reg or | |
3278 the lowpart subreg of one. */ | |
3279 if (plus_cst_src) | |
3280 { | |
3281 rtx reg = XEXP (plus_cst_src, 0); | |
3282 if (GET_CODE (reg) == SUBREG && subreg_lowpart_p (reg)) | |
3283 reg = SUBREG_REG (reg); | |
3284 | |
3285 if (!REG_P (reg) || REGNO (reg) >= FIRST_PSEUDO_REGISTER) | |
3286 plus_cst_src = 0; | |
3287 } | |
3288 } | |
3289 if (plus_cst_src) | |
3290 { | |
3291 rtx reg = XEXP (plus_cst_src, 0); | |
3292 HOST_WIDE_INT offset = INTVAL (XEXP (plus_cst_src, 1)); | |
3293 | |
3294 if (GET_CODE (reg) == SUBREG) | |
3295 reg = SUBREG_REG (reg); | |
3296 | |
3297 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++) | |
3298 if (ep->from_rtx == reg && ep->can_eliminate) | |
3299 { | |
3300 rtx to_rtx = ep->to_rtx; | |
3301 offset += ep->offset; | |
3302 offset = trunc_int_for_mode (offset, GET_MODE (plus_cst_src)); | |
3303 | |
3304 if (GET_CODE (XEXP (plus_cst_src, 0)) == SUBREG) | |
3305 to_rtx = gen_lowpart (GET_MODE (XEXP (plus_cst_src, 0)), | |
3306 to_rtx); | |
3307 /* If we have a nonzero offset, and the source is already | |
3308 a simple REG, the following transformation would | |
3309 increase the cost of the insn by replacing a simple REG | |
3310 with (plus (reg sp) CST). So try only when we already | |
3311 had a PLUS before. */ | |
3312 if (offset == 0 || plus_src) | |
3313 { | |
3314 rtx new_src = plus_constant (to_rtx, offset); | |
3315 | |
3316 new_body = old_body; | |
3317 if (! replace) | |
3318 { | |
3319 new_body = copy_insn (old_body); | |
3320 if (REG_NOTES (insn)) | |
3321 REG_NOTES (insn) = copy_insn_1 (REG_NOTES (insn)); | |
3322 } | |
3323 PATTERN (insn) = new_body; | |
3324 old_set = single_set (insn); | |
3325 | |
3326 /* First see if this insn remains valid when we make the | |
3327 change. If not, try to replace the whole pattern with | |
3328 a simple set (this may help if the original insn was a | |
3329 PARALLEL that was only recognized as single_set due to | |
3330 REG_UNUSED notes). If this isn't valid either, keep | |
3331 the INSN_CODE the same and let reload fix it up. */ | |
3332 if (!validate_change (insn, &SET_SRC (old_set), new_src, 0)) | |
3333 { | |
3334 rtx new_pat = gen_rtx_SET (VOIDmode, | |
3335 SET_DEST (old_set), new_src); | |
3336 | |
3337 if (!validate_change (insn, &PATTERN (insn), new_pat, 0)) | |
3338 SET_SRC (old_set) = new_src; | |
3339 } | |
3340 } | |
3341 else | |
3342 break; | |
3343 | |
3344 val = 1; | |
3345 /* This can't have an effect on elimination offsets, so skip right | |
3346 to the end. */ | |
3347 goto done; | |
3348 } | |
3349 } | |
3350 | |
3351 /* Determine the effects of this insn on elimination offsets. */ | |
3352 elimination_effects (old_body, 0); | |
3353 | |
3354 /* Eliminate all eliminable registers occurring in operands that | |
3355 can be handled by reload. */ | |
3356 extract_insn (insn); | |
3357 for (i = 0; i < recog_data.n_operands; i++) | |
3358 { | |
3359 orig_operand[i] = recog_data.operand[i]; | |
3360 substed_operand[i] = recog_data.operand[i]; | |
3361 | |
3362 /* For an asm statement, every operand is eliminable. */ | |
3363 if (insn_is_asm || insn_data[icode].operand[i].eliminable) | |
3364 { | |
3365 bool is_set_src, in_plus; | |
3366 | |
3367 /* Check for setting a register that we know about. */ | |
3368 if (recog_data.operand_type[i] != OP_IN | |
3369 && REG_P (orig_operand[i])) | |
3370 { | |
3371 /* If we are assigning to a register that can be eliminated, it | |
3372 must be as part of a PARALLEL, since the code above handles | |
3373 single SETs. We must indicate that we can no longer | |
3374 eliminate this reg. */ | |
3375 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; | |
3376 ep++) | |
3377 if (ep->from_rtx == orig_operand[i]) | |
3378 ep->can_eliminate = 0; | |
3379 } | |
3380 | |
3381 /* Companion to the above plus substitution, we can allow | |
3382 invariants as the source of a plain move. */ | |
3383 is_set_src = false; | |
3384 if (old_set && recog_data.operand_loc[i] == &SET_SRC (old_set)) | |
3385 is_set_src = true; | |
3386 in_plus = false; | |
3387 if (plus_src | |
3388 && (recog_data.operand_loc[i] == &XEXP (plus_src, 0) | |
3389 || recog_data.operand_loc[i] == &XEXP (plus_src, 1))) | |
3390 in_plus = true; | |
3391 | |
3392 substed_operand[i] | |
3393 = eliminate_regs_1 (recog_data.operand[i], 0, | |
3394 replace ? insn : NULL_RTX, | |
3395 is_set_src || in_plus); | |
3396 if (substed_operand[i] != orig_operand[i]) | |
3397 val = 1; | |
3398 /* Terminate the search in check_eliminable_occurrences at | |
3399 this point. */ | |
3400 *recog_data.operand_loc[i] = 0; | |
3401 | |
3402 /* If an output operand changed from a REG to a MEM and INSN is an | |
3403 insn, write a CLOBBER insn. */ | |
3404 if (recog_data.operand_type[i] != OP_IN | |
3405 && REG_P (orig_operand[i]) | |
3406 && MEM_P (substed_operand[i]) | |
3407 && replace) | |
3408 emit_insn_after (gen_clobber (orig_operand[i]), insn); | |
3409 } | |
3410 } | |
3411 | |
3412 for (i = 0; i < recog_data.n_dups; i++) | |
3413 *recog_data.dup_loc[i] | |
3414 = *recog_data.operand_loc[(int) recog_data.dup_num[i]]; | |
3415 | |
3416 /* If any eliminable remain, they aren't eliminable anymore. */ | |
3417 check_eliminable_occurrences (old_body); | |
3418 | |
3419 /* Substitute the operands; the new values are in the substed_operand | |
3420 array. */ | |
3421 for (i = 0; i < recog_data.n_operands; i++) | |
3422 *recog_data.operand_loc[i] = substed_operand[i]; | |
3423 for (i = 0; i < recog_data.n_dups; i++) | |
3424 *recog_data.dup_loc[i] = substed_operand[(int) recog_data.dup_num[i]]; | |
3425 | |
3426 /* If we are replacing a body that was a (set X (plus Y Z)), try to | |
3427 re-recognize the insn. We do this in case we had a simple addition | |
3428 but now can do this as a load-address. This saves an insn in this | |
3429 common case. | |
3430 If re-recognition fails, the old insn code number will still be used, | |
3431 and some register operands may have changed into PLUS expressions. | |
3432 These will be handled by find_reloads by loading them into a register | |
3433 again. */ | |
3434 | |
3435 if (val) | |
3436 { | |
3437 /* If we aren't replacing things permanently and we changed something, | |
3438 make another copy to ensure that all the RTL is new. Otherwise | |
3439 things can go wrong if find_reload swaps commutative operands | |
3440 and one is inside RTL that has been copied while the other is not. */ | |
3441 new_body = old_body; | |
3442 if (! replace) | |
3443 { | |
3444 new_body = copy_insn (old_body); | |
3445 if (REG_NOTES (insn)) | |
3446 REG_NOTES (insn) = copy_insn_1 (REG_NOTES (insn)); | |
3447 } | |
3448 PATTERN (insn) = new_body; | |
3449 | |
3450 /* If we had a move insn but now we don't, rerecognize it. This will | |
3451 cause spurious re-recognition if the old move had a PARALLEL since | |
3452 the new one still will, but we can't call single_set without | |
3453 having put NEW_BODY into the insn and the re-recognition won't | |
3454 hurt in this rare case. */ | |
3455 /* ??? Why this huge if statement - why don't we just rerecognize the | |
3456 thing always? */ | |
3457 if (! insn_is_asm | |
3458 && old_set != 0 | |
3459 && ((REG_P (SET_SRC (old_set)) | |
3460 && (GET_CODE (new_body) != SET | |
3461 || !REG_P (SET_SRC (new_body)))) | |
3462 /* If this was a load from or store to memory, compare | |
3463 the MEM in recog_data.operand to the one in the insn. | |
3464 If they are not equal, then rerecognize the insn. */ | |
3465 || (old_set != 0 | |
3466 && ((MEM_P (SET_SRC (old_set)) | |
3467 && SET_SRC (old_set) != recog_data.operand[1]) | |
3468 || (MEM_P (SET_DEST (old_set)) | |
3469 && SET_DEST (old_set) != recog_data.operand[0]))) | |
3470 /* If this was an add insn before, rerecognize. */ | |
3471 || GET_CODE (SET_SRC (old_set)) == PLUS)) | |
3472 { | |
3473 int new_icode = recog (PATTERN (insn), insn, 0); | |
3474 if (new_icode >= 0) | |
3475 INSN_CODE (insn) = new_icode; | |
3476 } | |
3477 } | |
3478 | |
3479 /* Restore the old body. If there were any changes to it, we made a copy | |
3480 of it while the changes were still in place, so we'll correctly return | |
3481 a modified insn below. */ | |
3482 if (! replace) | |
3483 { | |
3484 /* Restore the old body. */ | |
3485 for (i = 0; i < recog_data.n_operands; i++) | |
3486 *recog_data.operand_loc[i] = orig_operand[i]; | |
3487 for (i = 0; i < recog_data.n_dups; i++) | |
3488 *recog_data.dup_loc[i] = orig_operand[(int) recog_data.dup_num[i]]; | |
3489 } | |
3490 | |
3491 /* Update all elimination pairs to reflect the status after the current | |
3492 insn. The changes we make were determined by the earlier call to | |
3493 elimination_effects. | |
3494 | |
3495 We also detect cases where register elimination cannot be done, | |
3496 namely, if a register would be both changed and referenced outside a MEM | |
3497 in the resulting insn since such an insn is often undefined and, even if | |
3498 not, we cannot know what meaning will be given to it. Note that it is | |
3499 valid to have a register used in an address in an insn that changes it | |
3500 (presumably with a pre- or post-increment or decrement). | |
3501 | |
3502 If anything changes, return nonzero. */ | |
3503 | |
3504 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++) | |
3505 { | |
3506 if (ep->previous_offset != ep->offset && ep->ref_outside_mem) | |
3507 ep->can_eliminate = 0; | |
3508 | |
3509 ep->ref_outside_mem = 0; | |
3510 | |
3511 if (ep->previous_offset != ep->offset) | |
3512 val = 1; | |
3513 } | |
3514 | |
3515 done: | |
3516 /* If we changed something, perform elimination in REG_NOTES. This is | |
3517 needed even when REPLACE is zero because a REG_DEAD note might refer | |
3518 to a register that we eliminate and could cause a different number | |
3519 of spill registers to be needed in the final reload pass than in | |
3520 the pre-passes. */ | |
3521 if (val && REG_NOTES (insn) != 0) | |
3522 REG_NOTES (insn) | |
3523 = eliminate_regs_1 (REG_NOTES (insn), 0, REG_NOTES (insn), true); | |
3524 | |
3525 return val; | |
3526 } | |
3527 | |
3528 /* Loop through all elimination pairs. | |
3529 Recalculate the number not at initial offset. | |
3530 | |
3531 Compute the maximum offset (minimum offset if the stack does not | |
3532 grow downward) for each elimination pair. */ | |
3533 | |
3534 static void | |
3535 update_eliminable_offsets (void) | |
3536 { | |
3537 struct elim_table *ep; | |
3538 | |
3539 num_not_at_initial_offset = 0; | |
3540 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++) | |
3541 { | |
3542 ep->previous_offset = ep->offset; | |
3543 if (ep->can_eliminate && ep->offset != ep->initial_offset) | |
3544 num_not_at_initial_offset++; | |
3545 } | |
3546 } | |
3547 | |
3548 /* Given X, a SET or CLOBBER of DEST, if DEST is the target of a register | |
3549 replacement we currently believe is valid, mark it as not eliminable if X | |
3550 modifies DEST in any way other than by adding a constant integer to it. | |
3551 | |
3552 If DEST is the frame pointer, we do nothing because we assume that | |
3553 all assignments to the hard frame pointer are nonlocal gotos and are being | |
3554 done at a time when they are valid and do not disturb anything else. | |
3555 Some machines want to eliminate a fake argument pointer with either the | |
3556 frame or stack pointer. Assignments to the hard frame pointer must not | |
3557 prevent this elimination. | |
3558 | |
3559 Called via note_stores from reload before starting its passes to scan | |
3560 the insns of the function. */ | |
3561 | |
3562 static void | |
3563 mark_not_eliminable (rtx dest, const_rtx x, void *data ATTRIBUTE_UNUSED) | |
3564 { | |
3565 unsigned int i; | |
3566 | |
3567 /* A SUBREG of a hard register here is just changing its mode. We should | |
3568 not see a SUBREG of an eliminable hard register, but check just in | |
3569 case. */ | |
3570 if (GET_CODE (dest) == SUBREG) | |
3571 dest = SUBREG_REG (dest); | |
3572 | |
3573 if (dest == hard_frame_pointer_rtx) | |
3574 return; | |
3575 | |
3576 for (i = 0; i < NUM_ELIMINABLE_REGS; i++) | |
3577 if (reg_eliminate[i].can_eliminate && dest == reg_eliminate[i].to_rtx | |
3578 && (GET_CODE (x) != SET | |
3579 || GET_CODE (SET_SRC (x)) != PLUS | |
3580 || XEXP (SET_SRC (x), 0) != dest | |
3581 || GET_CODE (XEXP (SET_SRC (x), 1)) != CONST_INT)) | |
3582 { | |
3583 reg_eliminate[i].can_eliminate_previous | |
3584 = reg_eliminate[i].can_eliminate = 0; | |
3585 num_eliminable--; | |
3586 } | |
3587 } | |
3588 | |
3589 /* Verify that the initial elimination offsets did not change since the | |
3590 last call to set_initial_elim_offsets. This is used to catch cases | |
3591 where something illegal happened during reload_as_needed that could | |
3592 cause incorrect code to be generated if we did not check for it. */ | |
3593 | |
3594 static bool | |
3595 verify_initial_elim_offsets (void) | |
3596 { | |
3597 HOST_WIDE_INT t; | |
3598 | |
3599 if (!num_eliminable) | |
3600 return true; | |
3601 | |
3602 #ifdef ELIMINABLE_REGS | |
3603 { | |
3604 struct elim_table *ep; | |
3605 | |
3606 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++) | |
3607 { | |
3608 INITIAL_ELIMINATION_OFFSET (ep->from, ep->to, t); | |
3609 if (t != ep->initial_offset) | |
3610 return false; | |
3611 } | |
3612 } | |
3613 #else | |
3614 INITIAL_FRAME_POINTER_OFFSET (t); | |
3615 if (t != reg_eliminate[0].initial_offset) | |
3616 return false; | |
3617 #endif | |
3618 | |
3619 return true; | |
3620 } | |
3621 | |
3622 /* Reset all offsets on eliminable registers to their initial values. */ | |
3623 | |
3624 static void | |
3625 set_initial_elim_offsets (void) | |
3626 { | |
3627 struct elim_table *ep = reg_eliminate; | |
3628 | |
3629 #ifdef ELIMINABLE_REGS | |
3630 for (; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++) | |
3631 { | |
3632 INITIAL_ELIMINATION_OFFSET (ep->from, ep->to, ep->initial_offset); | |
3633 ep->previous_offset = ep->offset = ep->initial_offset; | |
3634 } | |
3635 #else | |
3636 INITIAL_FRAME_POINTER_OFFSET (ep->initial_offset); | |
3637 ep->previous_offset = ep->offset = ep->initial_offset; | |
3638 #endif | |
3639 | |
3640 num_not_at_initial_offset = 0; | |
3641 } | |
3642 | |
3643 /* Subroutine of set_initial_label_offsets called via for_each_eh_label. */ | |
3644 | |
3645 static void | |
3646 set_initial_eh_label_offset (rtx label) | |
3647 { | |
3648 set_label_offsets (label, NULL_RTX, 1); | |
3649 } | |
3650 | |
3651 /* Initialize the known label offsets. | |
3652 Set a known offset for each forced label to be at the initial offset | |
3653 of each elimination. We do this because we assume that all | |
3654 computed jumps occur from a location where each elimination is | |
3655 at its initial offset. | |
3656 For all other labels, show that we don't know the offsets. */ | |
3657 | |
3658 static void | |
3659 set_initial_label_offsets (void) | |
3660 { | |
3661 rtx x; | |
3662 memset (offsets_known_at, 0, num_labels); | |
3663 | |
3664 for (x = forced_labels; x; x = XEXP (x, 1)) | |
3665 if (XEXP (x, 0)) | |
3666 set_label_offsets (XEXP (x, 0), NULL_RTX, 1); | |
3667 | |
3668 for_each_eh_label (set_initial_eh_label_offset); | |
3669 } | |
3670 | |
3671 /* Set all elimination offsets to the known values for the code label given | |
3672 by INSN. */ | |
3673 | |
3674 static void | |
3675 set_offsets_for_label (rtx insn) | |
3676 { | |
3677 unsigned int i; | |
3678 int label_nr = CODE_LABEL_NUMBER (insn); | |
3679 struct elim_table *ep; | |
3680 | |
3681 num_not_at_initial_offset = 0; | |
3682 for (i = 0, ep = reg_eliminate; i < NUM_ELIMINABLE_REGS; ep++, i++) | |
3683 { | |
3684 ep->offset = ep->previous_offset | |
3685 = offsets_at[label_nr - first_label_num][i]; | |
3686 if (ep->can_eliminate && ep->offset != ep->initial_offset) | |
3687 num_not_at_initial_offset++; | |
3688 } | |
3689 } | |
3690 | |
3691 /* See if anything that happened changes which eliminations are valid. | |
3692 For example, on the SPARC, whether or not the frame pointer can | |
3693 be eliminated can depend on what registers have been used. We need | |
3694 not check some conditions again (such as flag_omit_frame_pointer) | |
3695 since they can't have changed. */ | |
3696 | |
3697 static void | |
3698 update_eliminables (HARD_REG_SET *pset) | |
3699 { | |
3700 int previous_frame_pointer_needed = frame_pointer_needed; | |
3701 struct elim_table *ep; | |
3702 | |
3703 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++) | |
3704 if ((ep->from == HARD_FRAME_POINTER_REGNUM && FRAME_POINTER_REQUIRED) | |
3705 #ifdef ELIMINABLE_REGS | |
3706 || ! CAN_ELIMINATE (ep->from, ep->to) | |
3707 #endif | |
3708 ) | |
3709 ep->can_eliminate = 0; | |
3710 | |
3711 /* Look for the case where we have discovered that we can't replace | |
3712 register A with register B and that means that we will now be | |
3713 trying to replace register A with register C. This means we can | |
3714 no longer replace register C with register B and we need to disable | |
3715 such an elimination, if it exists. This occurs often with A == ap, | |
3716 B == sp, and C == fp. */ | |
3717 | |
3718 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++) | |
3719 { | |
3720 struct elim_table *op; | |
3721 int new_to = -1; | |
3722 | |
3723 if (! ep->can_eliminate && ep->can_eliminate_previous) | |
3724 { | |
3725 /* Find the current elimination for ep->from, if there is a | |
3726 new one. */ | |
3727 for (op = reg_eliminate; | |
3728 op < ®_eliminate[NUM_ELIMINABLE_REGS]; op++) | |
3729 if (op->from == ep->from && op->can_eliminate) | |
3730 { | |
3731 new_to = op->to; | |
3732 break; | |
3733 } | |
3734 | |
3735 /* See if there is an elimination of NEW_TO -> EP->TO. If so, | |
3736 disable it. */ | |
3737 for (op = reg_eliminate; | |
3738 op < ®_eliminate[NUM_ELIMINABLE_REGS]; op++) | |
3739 if (op->from == new_to && op->to == ep->to) | |
3740 op->can_eliminate = 0; | |
3741 } | |
3742 } | |
3743 | |
3744 /* See if any registers that we thought we could eliminate the previous | |
3745 time are no longer eliminable. If so, something has changed and we | |
3746 must spill the register. Also, recompute the number of eliminable | |
3747 registers and see if the frame pointer is needed; it is if there is | |
3748 no elimination of the frame pointer that we can perform. */ | |
3749 | |
3750 frame_pointer_needed = 1; | |
3751 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++) | |
3752 { | |
3753 if (ep->can_eliminate | |
3754 && ep->from == FRAME_POINTER_REGNUM | |
3755 && ep->to != HARD_FRAME_POINTER_REGNUM | |
3756 && (! SUPPORTS_STACK_ALIGNMENT | |
3757 || ! crtl->stack_realign_needed)) | |
3758 frame_pointer_needed = 0; | |
3759 | |
3760 if (! ep->can_eliminate && ep->can_eliminate_previous) | |
3761 { | |
3762 ep->can_eliminate_previous = 0; | |
3763 SET_HARD_REG_BIT (*pset, ep->from); | |
3764 num_eliminable--; | |
3765 } | |
3766 } | |
3767 | |
3768 /* If we didn't need a frame pointer last time, but we do now, spill | |
3769 the hard frame pointer. */ | |
3770 if (frame_pointer_needed && ! previous_frame_pointer_needed) | |
3771 SET_HARD_REG_BIT (*pset, HARD_FRAME_POINTER_REGNUM); | |
3772 } | |
3773 | |
3774 /* Return true if X is used as the target register of an elimination. */ | |
3775 | |
3776 bool | |
3777 elimination_target_reg_p (rtx x) | |
3778 { | |
3779 struct elim_table *ep; | |
3780 | |
3781 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++) | |
3782 if (ep->to_rtx == x && ep->can_eliminate) | |
3783 return true; | |
3784 | |
3785 return false; | |
3786 } | |
3787 | |
3788 /* Initialize the table of registers to eliminate. | |
3789 Pre-condition: global flag frame_pointer_needed has been set before | |
3790 calling this function. */ | |
3791 | |
3792 static void | |
3793 init_elim_table (void) | |
3794 { | |
3795 struct elim_table *ep; | |
3796 #ifdef ELIMINABLE_REGS | |
3797 const struct elim_table_1 *ep1; | |
3798 #endif | |
3799 | |
3800 if (!reg_eliminate) | |
3801 reg_eliminate = XCNEWVEC (struct elim_table, NUM_ELIMINABLE_REGS); | |
3802 | |
3803 num_eliminable = 0; | |
3804 | |
3805 #ifdef ELIMINABLE_REGS | |
3806 for (ep = reg_eliminate, ep1 = reg_eliminate_1; | |
3807 ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++, ep1++) | |
3808 { | |
3809 ep->from = ep1->from; | |
3810 ep->to = ep1->to; | |
3811 ep->can_eliminate = ep->can_eliminate_previous | |
3812 = (CAN_ELIMINATE (ep->from, ep->to) | |
3813 && ! (ep->to == STACK_POINTER_REGNUM | |
3814 && frame_pointer_needed | |
3815 && (! SUPPORTS_STACK_ALIGNMENT | |
3816 || ! stack_realign_fp))); | |
3817 } | |
3818 #else | |
3819 reg_eliminate[0].from = reg_eliminate_1[0].from; | |
3820 reg_eliminate[0].to = reg_eliminate_1[0].to; | |
3821 reg_eliminate[0].can_eliminate = reg_eliminate[0].can_eliminate_previous | |
3822 = ! frame_pointer_needed; | |
3823 #endif | |
3824 | |
3825 /* Count the number of eliminable registers and build the FROM and TO | |
3826 REG rtx's. Note that code in gen_rtx_REG will cause, e.g., | |
3827 gen_rtx_REG (Pmode, STACK_POINTER_REGNUM) to equal stack_pointer_rtx. | |
3828 We depend on this. */ | |
3829 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++) | |
3830 { | |
3831 num_eliminable += ep->can_eliminate; | |
3832 ep->from_rtx = gen_rtx_REG (Pmode, ep->from); | |
3833 ep->to_rtx = gen_rtx_REG (Pmode, ep->to); | |
3834 } | |
3835 } | |
3836 | |
3837 /* Kick all pseudos out of hard register REGNO. | |
3838 | |
3839 If CANT_ELIMINATE is nonzero, it means that we are doing this spill | |
3840 because we found we can't eliminate some register. In the case, no pseudos | |
3841 are allowed to be in the register, even if they are only in a block that | |
3842 doesn't require spill registers, unlike the case when we are spilling this | |
3843 hard reg to produce another spill register. | |
3844 | |
3845 Return nonzero if any pseudos needed to be kicked out. */ | |
3846 | |
3847 static void | |
3848 spill_hard_reg (unsigned int regno, int cant_eliminate) | |
3849 { | |
3850 int i; | |
3851 | |
3852 if (cant_eliminate) | |
3853 { | |
3854 SET_HARD_REG_BIT (bad_spill_regs_global, regno); | |
3855 df_set_regs_ever_live (regno, true); | |
3856 } | |
3857 | |
3858 /* Spill every pseudo reg that was allocated to this reg | |
3859 or to something that overlaps this reg. */ | |
3860 | |
3861 for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++) | |
3862 if (reg_renumber[i] >= 0 | |
3863 && (unsigned int) reg_renumber[i] <= regno | |
3864 && end_hard_regno (PSEUDO_REGNO_MODE (i), reg_renumber[i]) > regno) | |
3865 SET_REGNO_REG_SET (&spilled_pseudos, i); | |
3866 } | |
3867 | |
3868 /* After find_reload_regs has been run for all insn that need reloads, | |
3869 and/or spill_hard_regs was called, this function is used to actually | |
3870 spill pseudo registers and try to reallocate them. It also sets up the | |
3871 spill_regs array for use by choose_reload_regs. */ | |
3872 | |
3873 static int | |
3874 finish_spills (int global) | |
3875 { | |
3876 struct insn_chain *chain; | |
3877 int something_changed = 0; | |
3878 unsigned i; | |
3879 reg_set_iterator rsi; | |
3880 | |
3881 /* Build the spill_regs array for the function. */ | |
3882 /* If there are some registers still to eliminate and one of the spill regs | |
3883 wasn't ever used before, additional stack space may have to be | |
3884 allocated to store this register. Thus, we may have changed the offset | |
3885 between the stack and frame pointers, so mark that something has changed. | |
3886 | |
3887 One might think that we need only set VAL to 1 if this is a call-used | |
3888 register. However, the set of registers that must be saved by the | |
3889 prologue is not identical to the call-used set. For example, the | |
3890 register used by the call insn for the return PC is a call-used register, | |
3891 but must be saved by the prologue. */ | |
3892 | |
3893 n_spills = 0; | |
3894 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++) | |
3895 if (TEST_HARD_REG_BIT (used_spill_regs, i)) | |
3896 { | |
3897 spill_reg_order[i] = n_spills; | |
3898 spill_regs[n_spills++] = i; | |
3899 if (num_eliminable && ! df_regs_ever_live_p (i)) | |
3900 something_changed = 1; | |
3901 df_set_regs_ever_live (i, true); | |
3902 } | |
3903 else | |
3904 spill_reg_order[i] = -1; | |
3905 | |
3906 EXECUTE_IF_SET_IN_REG_SET (&spilled_pseudos, FIRST_PSEUDO_REGISTER, i, rsi) | |
3907 if (! ira_conflicts_p || reg_renumber[i] >= 0) | |
3908 { | |
3909 /* Record the current hard register the pseudo is allocated to | |
3910 in pseudo_previous_regs so we avoid reallocating it to the | |
3911 same hard reg in a later pass. */ | |
3912 gcc_assert (reg_renumber[i] >= 0); | |
3913 | |
3914 SET_HARD_REG_BIT (pseudo_previous_regs[i], reg_renumber[i]); | |
3915 /* Mark it as no longer having a hard register home. */ | |
3916 reg_renumber[i] = -1; | |
3917 if (ira_conflicts_p) | |
3918 /* Inform IRA about the change. */ | |
3919 ira_mark_allocation_change (i); | |
3920 /* We will need to scan everything again. */ | |
3921 something_changed = 1; | |
3922 } | |
3923 | |
3924 /* Retry global register allocation if possible. */ | |
3925 if (global && ira_conflicts_p) | |
3926 { | |
3927 unsigned int n; | |
3928 | |
3929 memset (pseudo_forbidden_regs, 0, max_regno * sizeof (HARD_REG_SET)); | |
3930 /* For every insn that needs reloads, set the registers used as spill | |
3931 regs in pseudo_forbidden_regs for every pseudo live across the | |
3932 insn. */ | |
3933 for (chain = insns_need_reload; chain; chain = chain->next_need_reload) | |
3934 { | |
3935 EXECUTE_IF_SET_IN_REG_SET | |
3936 (&chain->live_throughout, FIRST_PSEUDO_REGISTER, i, rsi) | |
3937 { | |
3938 IOR_HARD_REG_SET (pseudo_forbidden_regs[i], | |
3939 chain->used_spill_regs); | |
3940 } | |
3941 EXECUTE_IF_SET_IN_REG_SET | |
3942 (&chain->dead_or_set, FIRST_PSEUDO_REGISTER, i, rsi) | |
3943 { | |
3944 IOR_HARD_REG_SET (pseudo_forbidden_regs[i], | |
3945 chain->used_spill_regs); | |
3946 } | |
3947 } | |
3948 | |
3949 /* Retry allocating the pseudos spilled in IRA and the | |
3950 reload. For each reg, merge the various reg sets that | |
3951 indicate which hard regs can't be used, and call | |
3952 ira_reassign_pseudos. */ | |
3953 for (n = 0, i = FIRST_PSEUDO_REGISTER; i < (unsigned) max_regno; i++) | |
3954 if (reg_old_renumber[i] != reg_renumber[i]) | |
3955 { | |
3956 if (reg_renumber[i] < 0) | |
3957 temp_pseudo_reg_arr[n++] = i; | |
3958 else | |
3959 CLEAR_REGNO_REG_SET (&spilled_pseudos, i); | |
3960 } | |
3961 if (ira_reassign_pseudos (temp_pseudo_reg_arr, n, | |
3962 bad_spill_regs_global, | |
3963 pseudo_forbidden_regs, pseudo_previous_regs, | |
3964 &spilled_pseudos)) | |
3965 something_changed = 1; | |
3966 } | |
3967 /* Fix up the register information in the insn chain. | |
3968 This involves deleting those of the spilled pseudos which did not get | |
3969 a new hard register home from the live_{before,after} sets. */ | |
3970 for (chain = reload_insn_chain; chain; chain = chain->next) | |
3971 { | |
3972 HARD_REG_SET used_by_pseudos; | |
3973 HARD_REG_SET used_by_pseudos2; | |
3974 | |
3975 if (! ira_conflicts_p) | |
3976 { | |
3977 /* Don't do it for IRA because IRA and the reload still can | |
3978 assign hard registers to the spilled pseudos on next | |
3979 reload iterations. */ | |
3980 AND_COMPL_REG_SET (&chain->live_throughout, &spilled_pseudos); | |
3981 AND_COMPL_REG_SET (&chain->dead_or_set, &spilled_pseudos); | |
3982 } | |
3983 /* Mark any unallocated hard regs as available for spills. That | |
3984 makes inheritance work somewhat better. */ | |
3985 if (chain->need_reload) | |
3986 { | |
3987 REG_SET_TO_HARD_REG_SET (used_by_pseudos, &chain->live_throughout); | |
3988 REG_SET_TO_HARD_REG_SET (used_by_pseudos2, &chain->dead_or_set); | |
3989 IOR_HARD_REG_SET (used_by_pseudos, used_by_pseudos2); | |
3990 | |
3991 compute_use_by_pseudos (&used_by_pseudos, &chain->live_throughout); | |
3992 compute_use_by_pseudos (&used_by_pseudos, &chain->dead_or_set); | |
3993 /* Value of chain->used_spill_regs from previous iteration | |
3994 may be not included in the value calculated here because | |
3995 of possible removing caller-saves insns (see function | |
3996 delete_caller_save_insns. */ | |
3997 COMPL_HARD_REG_SET (chain->used_spill_regs, used_by_pseudos); | |
3998 AND_HARD_REG_SET (chain->used_spill_regs, used_spill_regs); | |
3999 } | |
4000 } | |
4001 | |
4002 CLEAR_REG_SET (&changed_allocation_pseudos); | |
4003 /* Let alter_reg modify the reg rtx's for the modified pseudos. */ | |
4004 for (i = FIRST_PSEUDO_REGISTER; i < (unsigned)max_regno; i++) | |
4005 { | |
4006 int regno = reg_renumber[i]; | |
4007 if (reg_old_renumber[i] == regno) | |
4008 continue; | |
4009 | |
4010 SET_REGNO_REG_SET (&changed_allocation_pseudos, i); | |
4011 | |
4012 alter_reg (i, reg_old_renumber[i], false); | |
4013 reg_old_renumber[i] = regno; | |
4014 if (dump_file) | |
4015 { | |
4016 if (regno == -1) | |
4017 fprintf (dump_file, " Register %d now on stack.\n\n", i); | |
4018 else | |
4019 fprintf (dump_file, " Register %d now in %d.\n\n", | |
4020 i, reg_renumber[i]); | |
4021 } | |
4022 } | |
4023 | |
4024 return something_changed; | |
4025 } | |
4026 | |
4027 /* Find all paradoxical subregs within X and update reg_max_ref_width. */ | |
4028 | |
4029 static void | |
4030 scan_paradoxical_subregs (rtx x) | |
4031 { | |
4032 int i; | |
4033 const char *fmt; | |
4034 enum rtx_code code = GET_CODE (x); | |
4035 | |
4036 switch (code) | |
4037 { | |
4038 case REG: | |
4039 case CONST_INT: | |
4040 case CONST: | |
4041 case SYMBOL_REF: | |
4042 case LABEL_REF: | |
4043 case CONST_DOUBLE: | |
4044 case CONST_FIXED: | |
4045 case CONST_VECTOR: /* shouldn't happen, but just in case. */ | |
4046 case CC0: | |
4047 case PC: | |
4048 case USE: | |
4049 case CLOBBER: | |
4050 return; | |
4051 | |
4052 case SUBREG: | |
4053 if (REG_P (SUBREG_REG (x)) | |
4054 && (GET_MODE_SIZE (GET_MODE (x)) | |
4055 > reg_max_ref_width[REGNO (SUBREG_REG (x))])) | |
4056 { | |
4057 reg_max_ref_width[REGNO (SUBREG_REG (x))] | |
4058 = GET_MODE_SIZE (GET_MODE (x)); | |
4059 mark_home_live_1 (REGNO (SUBREG_REG (x)), GET_MODE (x)); | |
4060 } | |
4061 return; | |
4062 | |
4063 default: | |
4064 break; | |
4065 } | |
4066 | |
4067 fmt = GET_RTX_FORMAT (code); | |
4068 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
4069 { | |
4070 if (fmt[i] == 'e') | |
4071 scan_paradoxical_subregs (XEXP (x, i)); | |
4072 else if (fmt[i] == 'E') | |
4073 { | |
4074 int j; | |
4075 for (j = XVECLEN (x, i) - 1; j >= 0; j--) | |
4076 scan_paradoxical_subregs (XVECEXP (x, i, j)); | |
4077 } | |
4078 } | |
4079 } | |
4080 | |
4081 /* A subroutine of reload_as_needed. If INSN has a REG_EH_REGION note, | |
4082 examine all of the reload insns between PREV and NEXT exclusive, and | |
4083 annotate all that may trap. */ | |
4084 | |
4085 static void | |
4086 fixup_eh_region_note (rtx insn, rtx prev, rtx next) | |
4087 { | |
4088 rtx note = find_reg_note (insn, REG_EH_REGION, NULL_RTX); | |
4089 unsigned int trap_count; | |
4090 rtx i; | |
4091 | |
4092 if (note == NULL) | |
4093 return; | |
4094 | |
4095 if (may_trap_p (PATTERN (insn))) | |
4096 trap_count = 1; | |
4097 else | |
4098 { | |
4099 remove_note (insn, note); | |
4100 trap_count = 0; | |
4101 } | |
4102 | |
4103 for (i = NEXT_INSN (prev); i != next; i = NEXT_INSN (i)) | |
4104 if (INSN_P (i) && i != insn && may_trap_p (PATTERN (i))) | |
4105 { | |
4106 trap_count++; | |
4107 add_reg_note (i, REG_EH_REGION, XEXP (note, 0)); | |
4108 } | |
4109 } | |
4110 | |
4111 /* Reload pseudo-registers into hard regs around each insn as needed. | |
4112 Additional register load insns are output before the insn that needs it | |
4113 and perhaps store insns after insns that modify the reloaded pseudo reg. | |
4114 | |
4115 reg_last_reload_reg and reg_reloaded_contents keep track of | |
4116 which registers are already available in reload registers. | |
4117 We update these for the reloads that we perform, | |
4118 as the insns are scanned. */ | |
4119 | |
4120 static void | |
4121 reload_as_needed (int live_known) | |
4122 { | |
4123 struct insn_chain *chain; | |
4124 #if defined (AUTO_INC_DEC) | |
4125 int i; | |
4126 #endif | |
4127 rtx x; | |
4128 | |
4129 memset (spill_reg_rtx, 0, sizeof spill_reg_rtx); | |
4130 memset (spill_reg_store, 0, sizeof spill_reg_store); | |
4131 reg_last_reload_reg = XCNEWVEC (rtx, max_regno); | |
4132 INIT_REG_SET (®_has_output_reload); | |
4133 CLEAR_HARD_REG_SET (reg_reloaded_valid); | |
4134 CLEAR_HARD_REG_SET (reg_reloaded_call_part_clobbered); | |
4135 | |
4136 set_initial_elim_offsets (); | |
4137 | |
4138 for (chain = reload_insn_chain; chain; chain = chain->next) | |
4139 { | |
4140 rtx prev = 0; | |
4141 rtx insn = chain->insn; | |
4142 rtx old_next = NEXT_INSN (insn); | |
4143 #ifdef AUTO_INC_DEC | |
4144 rtx old_prev = PREV_INSN (insn); | |
4145 #endif | |
4146 | |
4147 /* If we pass a label, copy the offsets from the label information | |
4148 into the current offsets of each elimination. */ | |
4149 if (LABEL_P (insn)) | |
4150 set_offsets_for_label (insn); | |
4151 | |
4152 else if (INSN_P (insn)) | |
4153 { | |
4154 regset_head regs_to_forget; | |
4155 INIT_REG_SET (®s_to_forget); | |
4156 note_stores (PATTERN (insn), forget_old_reloads_1, ®s_to_forget); | |
4157 | |
4158 /* If this is a USE and CLOBBER of a MEM, ensure that any | |
4159 references to eliminable registers have been removed. */ | |
4160 | |
4161 if ((GET_CODE (PATTERN (insn)) == USE | |
4162 || GET_CODE (PATTERN (insn)) == CLOBBER) | |
4163 && MEM_P (XEXP (PATTERN (insn), 0))) | |
4164 XEXP (XEXP (PATTERN (insn), 0), 0) | |
4165 = eliminate_regs (XEXP (XEXP (PATTERN (insn), 0), 0), | |
4166 GET_MODE (XEXP (PATTERN (insn), 0)), | |
4167 NULL_RTX); | |
4168 | |
4169 /* If we need to do register elimination processing, do so. | |
4170 This might delete the insn, in which case we are done. */ | |
4171 if ((num_eliminable || num_eliminable_invariants) && chain->need_elim) | |
4172 { | |
4173 eliminate_regs_in_insn (insn, 1); | |
4174 if (NOTE_P (insn)) | |
4175 { | |
4176 update_eliminable_offsets (); | |
4177 CLEAR_REG_SET (®s_to_forget); | |
4178 continue; | |
4179 } | |
4180 } | |
4181 | |
4182 /* If need_elim is nonzero but need_reload is zero, one might think | |
4183 that we could simply set n_reloads to 0. However, find_reloads | |
4184 could have done some manipulation of the insn (such as swapping | |
4185 commutative operands), and these manipulations are lost during | |
4186 the first pass for every insn that needs register elimination. | |
4187 So the actions of find_reloads must be redone here. */ | |
4188 | |
4189 if (! chain->need_elim && ! chain->need_reload | |
4190 && ! chain->need_operand_change) | |
4191 n_reloads = 0; | |
4192 /* First find the pseudo regs that must be reloaded for this insn. | |
4193 This info is returned in the tables reload_... (see reload.h). | |
4194 Also modify the body of INSN by substituting RELOAD | |
4195 rtx's for those pseudo regs. */ | |
4196 else | |
4197 { | |
4198 CLEAR_REG_SET (®_has_output_reload); | |
4199 CLEAR_HARD_REG_SET (reg_is_output_reload); | |
4200 | |
4201 find_reloads (insn, 1, spill_indirect_levels, live_known, | |
4202 spill_reg_order); | |
4203 } | |
4204 | |
4205 if (n_reloads > 0) | |
4206 { | |
4207 rtx next = NEXT_INSN (insn); | |
4208 rtx p; | |
4209 | |
4210 prev = PREV_INSN (insn); | |
4211 | |
4212 /* Now compute which reload regs to reload them into. Perhaps | |
4213 reusing reload regs from previous insns, or else output | |
4214 load insns to reload them. Maybe output store insns too. | |
4215 Record the choices of reload reg in reload_reg_rtx. */ | |
4216 choose_reload_regs (chain); | |
4217 | |
4218 /* Merge any reloads that we didn't combine for fear of | |
4219 increasing the number of spill registers needed but now | |
4220 discover can be safely merged. */ | |
4221 if (SMALL_REGISTER_CLASSES) | |
4222 merge_assigned_reloads (insn); | |
4223 | |
4224 /* Generate the insns to reload operands into or out of | |
4225 their reload regs. */ | |
4226 emit_reload_insns (chain); | |
4227 | |
4228 /* Substitute the chosen reload regs from reload_reg_rtx | |
4229 into the insn's body (or perhaps into the bodies of other | |
4230 load and store insn that we just made for reloading | |
4231 and that we moved the structure into). */ | |
4232 subst_reloads (insn); | |
4233 | |
4234 /* Adjust the exception region notes for loads and stores. */ | |
4235 if (flag_non_call_exceptions && !CALL_P (insn)) | |
4236 fixup_eh_region_note (insn, prev, next); | |
4237 | |
4238 /* If this was an ASM, make sure that all the reload insns | |
4239 we have generated are valid. If not, give an error | |
4240 and delete them. */ | |
4241 if (asm_noperands (PATTERN (insn)) >= 0) | |
4242 for (p = NEXT_INSN (prev); p != next; p = NEXT_INSN (p)) | |
4243 if (p != insn && INSN_P (p) | |
4244 && GET_CODE (PATTERN (p)) != USE | |
4245 && (recog_memoized (p) < 0 | |
4246 || (extract_insn (p), ! constrain_operands (1)))) | |
4247 { | |
4248 error_for_asm (insn, | |
4249 "%<asm%> operand requires " | |
4250 "impossible reload"); | |
4251 delete_insn (p); | |
4252 } | |
4253 } | |
4254 | |
4255 if (num_eliminable && chain->need_elim) | |
4256 update_eliminable_offsets (); | |
4257 | |
4258 /* Any previously reloaded spilled pseudo reg, stored in this insn, | |
4259 is no longer validly lying around to save a future reload. | |
4260 Note that this does not detect pseudos that were reloaded | |
4261 for this insn in order to be stored in | |
4262 (obeying register constraints). That is correct; such reload | |
4263 registers ARE still valid. */ | |
4264 forget_marked_reloads (®s_to_forget); | |
4265 CLEAR_REG_SET (®s_to_forget); | |
4266 | |
4267 /* There may have been CLOBBER insns placed after INSN. So scan | |
4268 between INSN and NEXT and use them to forget old reloads. */ | |
4269 for (x = NEXT_INSN (insn); x != old_next; x = NEXT_INSN (x)) | |
4270 if (NONJUMP_INSN_P (x) && GET_CODE (PATTERN (x)) == CLOBBER) | |
4271 note_stores (PATTERN (x), forget_old_reloads_1, NULL); | |
4272 | |
4273 #ifdef AUTO_INC_DEC | |
4274 /* Likewise for regs altered by auto-increment in this insn. | |
4275 REG_INC notes have been changed by reloading: | |
4276 find_reloads_address_1 records substitutions for them, | |
4277 which have been performed by subst_reloads above. */ | |
4278 for (i = n_reloads - 1; i >= 0; i--) | |
4279 { | |
4280 rtx in_reg = rld[i].in_reg; | |
4281 if (in_reg) | |
4282 { | |
4283 enum rtx_code code = GET_CODE (in_reg); | |
4284 /* PRE_INC / PRE_DEC will have the reload register ending up | |
4285 with the same value as the stack slot, but that doesn't | |
4286 hold true for POST_INC / POST_DEC. Either we have to | |
4287 convert the memory access to a true POST_INC / POST_DEC, | |
4288 or we can't use the reload register for inheritance. */ | |
4289 if ((code == POST_INC || code == POST_DEC) | |
4290 && TEST_HARD_REG_BIT (reg_reloaded_valid, | |
4291 REGNO (rld[i].reg_rtx)) | |
4292 /* Make sure it is the inc/dec pseudo, and not | |
4293 some other (e.g. output operand) pseudo. */ | |
4294 && ((unsigned) reg_reloaded_contents[REGNO (rld[i].reg_rtx)] | |
4295 == REGNO (XEXP (in_reg, 0)))) | |
4296 | |
4297 { | |
4298 rtx reload_reg = rld[i].reg_rtx; | |
4299 enum machine_mode mode = GET_MODE (reload_reg); | |
4300 int n = 0; | |
4301 rtx p; | |
4302 | |
4303 for (p = PREV_INSN (old_next); p != prev; p = PREV_INSN (p)) | |
4304 { | |
4305 /* We really want to ignore REG_INC notes here, so | |
4306 use PATTERN (p) as argument to reg_set_p . */ | |
4307 if (reg_set_p (reload_reg, PATTERN (p))) | |
4308 break; | |
4309 n = count_occurrences (PATTERN (p), reload_reg, 0); | |
4310 if (! n) | |
4311 continue; | |
4312 if (n == 1) | |
4313 { | |
4314 n = validate_replace_rtx (reload_reg, | |
4315 gen_rtx_fmt_e (code, | |
4316 mode, | |
4317 reload_reg), | |
4318 p); | |
4319 | |
4320 /* We must also verify that the constraints | |
4321 are met after the replacement. */ | |
4322 extract_insn (p); | |
4323 if (n) | |
4324 n = constrain_operands (1); | |
4325 else | |
4326 break; | |
4327 | |
4328 /* If the constraints were not met, then | |
4329 undo the replacement. */ | |
4330 if (!n) | |
4331 { | |
4332 validate_replace_rtx (gen_rtx_fmt_e (code, | |
4333 mode, | |
4334 reload_reg), | |
4335 reload_reg, p); | |
4336 break; | |
4337 } | |
4338 | |
4339 } | |
4340 break; | |
4341 } | |
4342 if (n == 1) | |
4343 { | |
4344 add_reg_note (p, REG_INC, reload_reg); | |
4345 /* Mark this as having an output reload so that the | |
4346 REG_INC processing code below won't invalidate | |
4347 the reload for inheritance. */ | |
4348 SET_HARD_REG_BIT (reg_is_output_reload, | |
4349 REGNO (reload_reg)); | |
4350 SET_REGNO_REG_SET (®_has_output_reload, | |
4351 REGNO (XEXP (in_reg, 0))); | |
4352 } | |
4353 else | |
4354 forget_old_reloads_1 (XEXP (in_reg, 0), NULL_RTX, | |
4355 NULL); | |
4356 } | |
4357 else if ((code == PRE_INC || code == PRE_DEC) | |
4358 && TEST_HARD_REG_BIT (reg_reloaded_valid, | |
4359 REGNO (rld[i].reg_rtx)) | |
4360 /* Make sure it is the inc/dec pseudo, and not | |
4361 some other (e.g. output operand) pseudo. */ | |
4362 && ((unsigned) reg_reloaded_contents[REGNO (rld[i].reg_rtx)] | |
4363 == REGNO (XEXP (in_reg, 0)))) | |
4364 { | |
4365 SET_HARD_REG_BIT (reg_is_output_reload, | |
4366 REGNO (rld[i].reg_rtx)); | |
4367 SET_REGNO_REG_SET (®_has_output_reload, | |
4368 REGNO (XEXP (in_reg, 0))); | |
4369 } | |
4370 else if (code == PRE_INC || code == PRE_DEC | |
4371 || code == POST_INC || code == POST_DEC) | |
4372 { | |
4373 int in_regno = REGNO (XEXP (in_reg, 0)); | |
4374 | |
4375 if (reg_last_reload_reg[in_regno] != NULL_RTX) | |
4376 { | |
4377 int in_hard_regno; | |
4378 bool forget_p = true; | |
4379 | |
4380 in_hard_regno = REGNO (reg_last_reload_reg[in_regno]); | |
4381 if (TEST_HARD_REG_BIT (reg_reloaded_valid, | |
4382 in_hard_regno)) | |
4383 { | |
4384 for (x = old_prev ? NEXT_INSN (old_prev) : insn; | |
4385 x != old_next; | |
4386 x = NEXT_INSN (x)) | |
4387 if (x == reg_reloaded_insn[in_hard_regno]) | |
4388 { | |
4389 forget_p = false; | |
4390 break; | |
4391 } | |
4392 } | |
4393 /* If for some reasons, we didn't set up | |
4394 reg_last_reload_reg in this insn, | |
4395 invalidate inheritance from previous | |
4396 insns for the incremented/decremented | |
4397 register. Such registers will be not in | |
4398 reg_has_output_reload. Invalidate it | |
4399 also if the corresponding element in | |
4400 reg_reloaded_insn is also | |
4401 invalidated. */ | |
4402 if (forget_p) | |
4403 forget_old_reloads_1 (XEXP (in_reg, 0), | |
4404 NULL_RTX, NULL); | |
4405 } | |
4406 } | |
4407 } | |
4408 } | |
4409 /* If a pseudo that got a hard register is auto-incremented, | |
4410 we must purge records of copying it into pseudos without | |
4411 hard registers. */ | |
4412 for (x = REG_NOTES (insn); x; x = XEXP (x, 1)) | |
4413 if (REG_NOTE_KIND (x) == REG_INC) | |
4414 { | |
4415 /* See if this pseudo reg was reloaded in this insn. | |
4416 If so, its last-reload info is still valid | |
4417 because it is based on this insn's reload. */ | |
4418 for (i = 0; i < n_reloads; i++) | |
4419 if (rld[i].out == XEXP (x, 0)) | |
4420 break; | |
4421 | |
4422 if (i == n_reloads) | |
4423 forget_old_reloads_1 (XEXP (x, 0), NULL_RTX, NULL); | |
4424 } | |
4425 #endif | |
4426 } | |
4427 /* A reload reg's contents are unknown after a label. */ | |
4428 if (LABEL_P (insn)) | |
4429 CLEAR_HARD_REG_SET (reg_reloaded_valid); | |
4430 | |
4431 /* Don't assume a reload reg is still good after a call insn | |
4432 if it is a call-used reg, or if it contains a value that will | |
4433 be partially clobbered by the call. */ | |
4434 else if (CALL_P (insn)) | |
4435 { | |
4436 AND_COMPL_HARD_REG_SET (reg_reloaded_valid, call_used_reg_set); | |
4437 AND_COMPL_HARD_REG_SET (reg_reloaded_valid, reg_reloaded_call_part_clobbered); | |
4438 } | |
4439 } | |
4440 | |
4441 /* Clean up. */ | |
4442 free (reg_last_reload_reg); | |
4443 CLEAR_REG_SET (®_has_output_reload); | |
4444 } | |
4445 | |
4446 /* Discard all record of any value reloaded from X, | |
4447 or reloaded in X from someplace else; | |
4448 unless X is an output reload reg of the current insn. | |
4449 | |
4450 X may be a hard reg (the reload reg) | |
4451 or it may be a pseudo reg that was reloaded from. | |
4452 | |
4453 When DATA is non-NULL just mark the registers in regset | |
4454 to be forgotten later. */ | |
4455 | |
4456 static void | |
4457 forget_old_reloads_1 (rtx x, const_rtx ignored ATTRIBUTE_UNUSED, | |
4458 void *data) | |
4459 { | |
4460 unsigned int regno; | |
4461 unsigned int nr; | |
4462 regset regs = (regset) data; | |
4463 | |
4464 /* note_stores does give us subregs of hard regs, | |
4465 subreg_regno_offset requires a hard reg. */ | |
4466 while (GET_CODE (x) == SUBREG) | |
4467 { | |
4468 /* We ignore the subreg offset when calculating the regno, | |
4469 because we are using the entire underlying hard register | |
4470 below. */ | |
4471 x = SUBREG_REG (x); | |
4472 } | |
4473 | |
4474 if (!REG_P (x)) | |
4475 return; | |
4476 | |
4477 regno = REGNO (x); | |
4478 | |
4479 if (regno >= FIRST_PSEUDO_REGISTER) | |
4480 nr = 1; | |
4481 else | |
4482 { | |
4483 unsigned int i; | |
4484 | |
4485 nr = hard_regno_nregs[regno][GET_MODE (x)]; | |
4486 /* Storing into a spilled-reg invalidates its contents. | |
4487 This can happen if a block-local pseudo is allocated to that reg | |
4488 and it wasn't spilled because this block's total need is 0. | |
4489 Then some insn might have an optional reload and use this reg. */ | |
4490 if (!regs) | |
4491 for (i = 0; i < nr; i++) | |
4492 /* But don't do this if the reg actually serves as an output | |
4493 reload reg in the current instruction. */ | |
4494 if (n_reloads == 0 | |
4495 || ! TEST_HARD_REG_BIT (reg_is_output_reload, regno + i)) | |
4496 { | |
4497 CLEAR_HARD_REG_BIT (reg_reloaded_valid, regno + i); | |
4498 spill_reg_store[regno + i] = 0; | |
4499 } | |
4500 } | |
4501 | |
4502 if (regs) | |
4503 while (nr-- > 0) | |
4504 SET_REGNO_REG_SET (regs, regno + nr); | |
4505 else | |
4506 { | |
4507 /* Since value of X has changed, | |
4508 forget any value previously copied from it. */ | |
4509 | |
4510 while (nr-- > 0) | |
4511 /* But don't forget a copy if this is the output reload | |
4512 that establishes the copy's validity. */ | |
4513 if (n_reloads == 0 | |
4514 || !REGNO_REG_SET_P (®_has_output_reload, regno + nr)) | |
4515 reg_last_reload_reg[regno + nr] = 0; | |
4516 } | |
4517 } | |
4518 | |
4519 /* Forget the reloads marked in regset by previous function. */ | |
4520 static void | |
4521 forget_marked_reloads (regset regs) | |
4522 { | |
4523 unsigned int reg; | |
4524 reg_set_iterator rsi; | |
4525 EXECUTE_IF_SET_IN_REG_SET (regs, 0, reg, rsi) | |
4526 { | |
4527 if (reg < FIRST_PSEUDO_REGISTER | |
4528 /* But don't do this if the reg actually serves as an output | |
4529 reload reg in the current instruction. */ | |
4530 && (n_reloads == 0 | |
4531 || ! TEST_HARD_REG_BIT (reg_is_output_reload, reg))) | |
4532 { | |
4533 CLEAR_HARD_REG_BIT (reg_reloaded_valid, reg); | |
4534 spill_reg_store[reg] = 0; | |
4535 } | |
4536 if (n_reloads == 0 | |
4537 || !REGNO_REG_SET_P (®_has_output_reload, reg)) | |
4538 reg_last_reload_reg[reg] = 0; | |
4539 } | |
4540 } | |
4541 | |
4542 /* The following HARD_REG_SETs indicate when each hard register is | |
4543 used for a reload of various parts of the current insn. */ | |
4544 | |
4545 /* If reg is unavailable for all reloads. */ | |
4546 static HARD_REG_SET reload_reg_unavailable; | |
4547 /* If reg is in use as a reload reg for a RELOAD_OTHER reload. */ | |
4548 static HARD_REG_SET reload_reg_used; | |
4549 /* If reg is in use for a RELOAD_FOR_INPUT_ADDRESS reload for operand I. */ | |
4550 static HARD_REG_SET reload_reg_used_in_input_addr[MAX_RECOG_OPERANDS]; | |
4551 /* If reg is in use for a RELOAD_FOR_INPADDR_ADDRESS reload for operand I. */ | |
4552 static HARD_REG_SET reload_reg_used_in_inpaddr_addr[MAX_RECOG_OPERANDS]; | |
4553 /* If reg is in use for a RELOAD_FOR_OUTPUT_ADDRESS reload for operand I. */ | |
4554 static HARD_REG_SET reload_reg_used_in_output_addr[MAX_RECOG_OPERANDS]; | |
4555 /* If reg is in use for a RELOAD_FOR_OUTADDR_ADDRESS reload for operand I. */ | |
4556 static HARD_REG_SET reload_reg_used_in_outaddr_addr[MAX_RECOG_OPERANDS]; | |
4557 /* If reg is in use for a RELOAD_FOR_INPUT reload for operand I. */ | |
4558 static HARD_REG_SET reload_reg_used_in_input[MAX_RECOG_OPERANDS]; | |
4559 /* If reg is in use for a RELOAD_FOR_OUTPUT reload for operand I. */ | |
4560 static HARD_REG_SET reload_reg_used_in_output[MAX_RECOG_OPERANDS]; | |
4561 /* If reg is in use for a RELOAD_FOR_OPERAND_ADDRESS reload. */ | |
4562 static HARD_REG_SET reload_reg_used_in_op_addr; | |
4563 /* If reg is in use for a RELOAD_FOR_OPADDR_ADDR reload. */ | |
4564 static HARD_REG_SET reload_reg_used_in_op_addr_reload; | |
4565 /* If reg is in use for a RELOAD_FOR_INSN reload. */ | |
4566 static HARD_REG_SET reload_reg_used_in_insn; | |
4567 /* If reg is in use for a RELOAD_FOR_OTHER_ADDRESS reload. */ | |
4568 static HARD_REG_SET reload_reg_used_in_other_addr; | |
4569 | |
4570 /* If reg is in use as a reload reg for any sort of reload. */ | |
4571 static HARD_REG_SET reload_reg_used_at_all; | |
4572 | |
4573 /* If reg is use as an inherited reload. We just mark the first register | |
4574 in the group. */ | |
4575 static HARD_REG_SET reload_reg_used_for_inherit; | |
4576 | |
4577 /* Records which hard regs are used in any way, either as explicit use or | |
4578 by being allocated to a pseudo during any point of the current insn. */ | |
4579 static HARD_REG_SET reg_used_in_insn; | |
4580 | |
4581 /* Mark reg REGNO as in use for a reload of the sort spec'd by OPNUM and | |
4582 TYPE. MODE is used to indicate how many consecutive regs are | |
4583 actually used. */ | |
4584 | |
4585 static void | |
4586 mark_reload_reg_in_use (unsigned int regno, int opnum, enum reload_type type, | |
4587 enum machine_mode mode) | |
4588 { | |
4589 unsigned int nregs = hard_regno_nregs[regno][mode]; | |
4590 unsigned int i; | |
4591 | |
4592 for (i = regno; i < nregs + regno; i++) | |
4593 { | |
4594 switch (type) | |
4595 { | |
4596 case RELOAD_OTHER: | |
4597 SET_HARD_REG_BIT (reload_reg_used, i); | |
4598 break; | |
4599 | |
4600 case RELOAD_FOR_INPUT_ADDRESS: | |
4601 SET_HARD_REG_BIT (reload_reg_used_in_input_addr[opnum], i); | |
4602 break; | |
4603 | |
4604 case RELOAD_FOR_INPADDR_ADDRESS: | |
4605 SET_HARD_REG_BIT (reload_reg_used_in_inpaddr_addr[opnum], i); | |
4606 break; | |
4607 | |
4608 case RELOAD_FOR_OUTPUT_ADDRESS: | |
4609 SET_HARD_REG_BIT (reload_reg_used_in_output_addr[opnum], i); | |
4610 break; | |
4611 | |
4612 case RELOAD_FOR_OUTADDR_ADDRESS: | |
4613 SET_HARD_REG_BIT (reload_reg_used_in_outaddr_addr[opnum], i); | |
4614 break; | |
4615 | |
4616 case RELOAD_FOR_OPERAND_ADDRESS: | |
4617 SET_HARD_REG_BIT (reload_reg_used_in_op_addr, i); | |
4618 break; | |
4619 | |
4620 case RELOAD_FOR_OPADDR_ADDR: | |
4621 SET_HARD_REG_BIT (reload_reg_used_in_op_addr_reload, i); | |
4622 break; | |
4623 | |
4624 case RELOAD_FOR_OTHER_ADDRESS: | |
4625 SET_HARD_REG_BIT (reload_reg_used_in_other_addr, i); | |
4626 break; | |
4627 | |
4628 case RELOAD_FOR_INPUT: | |
4629 SET_HARD_REG_BIT (reload_reg_used_in_input[opnum], i); | |
4630 break; | |
4631 | |
4632 case RELOAD_FOR_OUTPUT: | |
4633 SET_HARD_REG_BIT (reload_reg_used_in_output[opnum], i); | |
4634 break; | |
4635 | |
4636 case RELOAD_FOR_INSN: | |
4637 SET_HARD_REG_BIT (reload_reg_used_in_insn, i); | |
4638 break; | |
4639 } | |
4640 | |
4641 SET_HARD_REG_BIT (reload_reg_used_at_all, i); | |
4642 } | |
4643 } | |
4644 | |
4645 /* Similarly, but show REGNO is no longer in use for a reload. */ | |
4646 | |
4647 static void | |
4648 clear_reload_reg_in_use (unsigned int regno, int opnum, | |
4649 enum reload_type type, enum machine_mode mode) | |
4650 { | |
4651 unsigned int nregs = hard_regno_nregs[regno][mode]; | |
4652 unsigned int start_regno, end_regno, r; | |
4653 int i; | |
4654 /* A complication is that for some reload types, inheritance might | |
4655 allow multiple reloads of the same types to share a reload register. | |
4656 We set check_opnum if we have to check only reloads with the same | |
4657 operand number, and check_any if we have to check all reloads. */ | |
4658 int check_opnum = 0; | |
4659 int check_any = 0; | |
4660 HARD_REG_SET *used_in_set; | |
4661 | |
4662 switch (type) | |
4663 { | |
4664 case RELOAD_OTHER: | |
4665 used_in_set = &reload_reg_used; | |
4666 break; | |
4667 | |
4668 case RELOAD_FOR_INPUT_ADDRESS: | |
4669 used_in_set = &reload_reg_used_in_input_addr[opnum]; | |
4670 break; | |
4671 | |
4672 case RELOAD_FOR_INPADDR_ADDRESS: | |
4673 check_opnum = 1; | |
4674 used_in_set = &reload_reg_used_in_inpaddr_addr[opnum]; | |
4675 break; | |
4676 | |
4677 case RELOAD_FOR_OUTPUT_ADDRESS: | |
4678 used_in_set = &reload_reg_used_in_output_addr[opnum]; | |
4679 break; | |
4680 | |
4681 case RELOAD_FOR_OUTADDR_ADDRESS: | |
4682 check_opnum = 1; | |
4683 used_in_set = &reload_reg_used_in_outaddr_addr[opnum]; | |
4684 break; | |
4685 | |
4686 case RELOAD_FOR_OPERAND_ADDRESS: | |
4687 used_in_set = &reload_reg_used_in_op_addr; | |
4688 break; | |
4689 | |
4690 case RELOAD_FOR_OPADDR_ADDR: | |
4691 check_any = 1; | |
4692 used_in_set = &reload_reg_used_in_op_addr_reload; | |
4693 break; | |
4694 | |
4695 case RELOAD_FOR_OTHER_ADDRESS: | |
4696 used_in_set = &reload_reg_used_in_other_addr; | |
4697 check_any = 1; | |
4698 break; | |
4699 | |
4700 case RELOAD_FOR_INPUT: | |
4701 used_in_set = &reload_reg_used_in_input[opnum]; | |
4702 break; | |
4703 | |
4704 case RELOAD_FOR_OUTPUT: | |
4705 used_in_set = &reload_reg_used_in_output[opnum]; | |
4706 break; | |
4707 | |
4708 case RELOAD_FOR_INSN: | |
4709 used_in_set = &reload_reg_used_in_insn; | |
4710 break; | |
4711 default: | |
4712 gcc_unreachable (); | |
4713 } | |
4714 /* We resolve conflicts with remaining reloads of the same type by | |
4715 excluding the intervals of reload registers by them from the | |
4716 interval of freed reload registers. Since we only keep track of | |
4717 one set of interval bounds, we might have to exclude somewhat | |
4718 more than what would be necessary if we used a HARD_REG_SET here. | |
4719 But this should only happen very infrequently, so there should | |
4720 be no reason to worry about it. */ | |
4721 | |
4722 start_regno = regno; | |
4723 end_regno = regno + nregs; | |
4724 if (check_opnum || check_any) | |
4725 { | |
4726 for (i = n_reloads - 1; i >= 0; i--) | |
4727 { | |
4728 if (rld[i].when_needed == type | |
4729 && (check_any || rld[i].opnum == opnum) | |
4730 && rld[i].reg_rtx) | |
4731 { | |
4732 unsigned int conflict_start = true_regnum (rld[i].reg_rtx); | |
4733 unsigned int conflict_end | |
4734 = end_hard_regno (rld[i].mode, conflict_start); | |
4735 | |
4736 /* If there is an overlap with the first to-be-freed register, | |
4737 adjust the interval start. */ | |
4738 if (conflict_start <= start_regno && conflict_end > start_regno) | |
4739 start_regno = conflict_end; | |
4740 /* Otherwise, if there is a conflict with one of the other | |
4741 to-be-freed registers, adjust the interval end. */ | |
4742 if (conflict_start > start_regno && conflict_start < end_regno) | |
4743 end_regno = conflict_start; | |
4744 } | |
4745 } | |
4746 } | |
4747 | |
4748 for (r = start_regno; r < end_regno; r++) | |
4749 CLEAR_HARD_REG_BIT (*used_in_set, r); | |
4750 } | |
4751 | |
4752 /* 1 if reg REGNO is free as a reload reg for a reload of the sort | |
4753 specified by OPNUM and TYPE. */ | |
4754 | |
4755 static int | |
4756 reload_reg_free_p (unsigned int regno, int opnum, enum reload_type type) | |
4757 { | |
4758 int i; | |
4759 | |
4760 /* In use for a RELOAD_OTHER means it's not available for anything. */ | |
4761 if (TEST_HARD_REG_BIT (reload_reg_used, regno) | |
4762 || TEST_HARD_REG_BIT (reload_reg_unavailable, regno)) | |
4763 return 0; | |
4764 | |
4765 switch (type) | |
4766 { | |
4767 case RELOAD_OTHER: | |
4768 /* In use for anything means we can't use it for RELOAD_OTHER. */ | |
4769 if (TEST_HARD_REG_BIT (reload_reg_used_in_other_addr, regno) | |
4770 || TEST_HARD_REG_BIT (reload_reg_used_in_op_addr, regno) | |
4771 || TEST_HARD_REG_BIT (reload_reg_used_in_op_addr_reload, regno) | |
4772 || TEST_HARD_REG_BIT (reload_reg_used_in_insn, regno)) | |
4773 return 0; | |
4774 | |
4775 for (i = 0; i < reload_n_operands; i++) | |
4776 if (TEST_HARD_REG_BIT (reload_reg_used_in_input_addr[i], regno) | |
4777 || TEST_HARD_REG_BIT (reload_reg_used_in_inpaddr_addr[i], regno) | |
4778 || TEST_HARD_REG_BIT (reload_reg_used_in_output_addr[i], regno) | |
4779 || TEST_HARD_REG_BIT (reload_reg_used_in_outaddr_addr[i], regno) | |
4780 || TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno) | |
4781 || TEST_HARD_REG_BIT (reload_reg_used_in_output[i], regno)) | |
4782 return 0; | |
4783 | |
4784 return 1; | |
4785 | |
4786 case RELOAD_FOR_INPUT: | |
4787 if (TEST_HARD_REG_BIT (reload_reg_used_in_insn, regno) | |
4788 || TEST_HARD_REG_BIT (reload_reg_used_in_op_addr, regno)) | |
4789 return 0; | |
4790 | |
4791 if (TEST_HARD_REG_BIT (reload_reg_used_in_op_addr_reload, regno)) | |
4792 return 0; | |
4793 | |
4794 /* If it is used for some other input, can't use it. */ | |
4795 for (i = 0; i < reload_n_operands; i++) | |
4796 if (TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno)) | |
4797 return 0; | |
4798 | |
4799 /* If it is used in a later operand's address, can't use it. */ | |
4800 for (i = opnum + 1; i < reload_n_operands; i++) | |
4801 if (TEST_HARD_REG_BIT (reload_reg_used_in_input_addr[i], regno) | |
4802 || TEST_HARD_REG_BIT (reload_reg_used_in_inpaddr_addr[i], regno)) | |
4803 return 0; | |
4804 | |
4805 return 1; | |
4806 | |
4807 case RELOAD_FOR_INPUT_ADDRESS: | |
4808 /* Can't use a register if it is used for an input address for this | |
4809 operand or used as an input in an earlier one. */ | |
4810 if (TEST_HARD_REG_BIT (reload_reg_used_in_input_addr[opnum], regno) | |
4811 || TEST_HARD_REG_BIT (reload_reg_used_in_inpaddr_addr[opnum], regno)) | |
4812 return 0; | |
4813 | |
4814 for (i = 0; i < opnum; i++) | |
4815 if (TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno)) | |
4816 return 0; | |
4817 | |
4818 return 1; | |
4819 | |
4820 case RELOAD_FOR_INPADDR_ADDRESS: | |
4821 /* Can't use a register if it is used for an input address | |
4822 for this operand or used as an input in an earlier | |
4823 one. */ | |
4824 if (TEST_HARD_REG_BIT (reload_reg_used_in_inpaddr_addr[opnum], regno)) | |
4825 return 0; | |
4826 | |
4827 for (i = 0; i < opnum; i++) | |
4828 if (TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno)) | |
4829 return 0; | |
4830 | |
4831 return 1; | |
4832 | |
4833 case RELOAD_FOR_OUTPUT_ADDRESS: | |
4834 /* Can't use a register if it is used for an output address for this | |
4835 operand or used as an output in this or a later operand. Note | |
4836 that multiple output operands are emitted in reverse order, so | |
4837 the conflicting ones are those with lower indices. */ | |
4838 if (TEST_HARD_REG_BIT (reload_reg_used_in_output_addr[opnum], regno)) | |
4839 return 0; | |
4840 | |
4841 for (i = 0; i <= opnum; i++) | |
4842 if (TEST_HARD_REG_BIT (reload_reg_used_in_output[i], regno)) | |
4843 return 0; | |
4844 | |
4845 return 1; | |
4846 | |
4847 case RELOAD_FOR_OUTADDR_ADDRESS: | |
4848 /* Can't use a register if it is used for an output address | |
4849 for this operand or used as an output in this or a | |
4850 later operand. Note that multiple output operands are | |
4851 emitted in reverse order, so the conflicting ones are | |
4852 those with lower indices. */ | |
4853 if (TEST_HARD_REG_BIT (reload_reg_used_in_outaddr_addr[opnum], regno)) | |
4854 return 0; | |
4855 | |
4856 for (i = 0; i <= opnum; i++) | |
4857 if (TEST_HARD_REG_BIT (reload_reg_used_in_output[i], regno)) | |
4858 return 0; | |
4859 | |
4860 return 1; | |
4861 | |
4862 case RELOAD_FOR_OPERAND_ADDRESS: | |
4863 for (i = 0; i < reload_n_operands; i++) | |
4864 if (TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno)) | |
4865 return 0; | |
4866 | |
4867 return (! TEST_HARD_REG_BIT (reload_reg_used_in_insn, regno) | |
4868 && ! TEST_HARD_REG_BIT (reload_reg_used_in_op_addr, regno)); | |
4869 | |
4870 case RELOAD_FOR_OPADDR_ADDR: | |
4871 for (i = 0; i < reload_n_operands; i++) | |
4872 if (TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno)) | |
4873 return 0; | |
4874 | |
4875 return (!TEST_HARD_REG_BIT (reload_reg_used_in_op_addr_reload, regno)); | |
4876 | |
4877 case RELOAD_FOR_OUTPUT: | |
4878 /* This cannot share a register with RELOAD_FOR_INSN reloads, other | |
4879 outputs, or an operand address for this or an earlier output. | |
4880 Note that multiple output operands are emitted in reverse order, | |
4881 so the conflicting ones are those with higher indices. */ | |
4882 if (TEST_HARD_REG_BIT (reload_reg_used_in_insn, regno)) | |
4883 return 0; | |
4884 | |
4885 for (i = 0; i < reload_n_operands; i++) | |
4886 if (TEST_HARD_REG_BIT (reload_reg_used_in_output[i], regno)) | |
4887 return 0; | |
4888 | |
4889 for (i = opnum; i < reload_n_operands; i++) | |
4890 if (TEST_HARD_REG_BIT (reload_reg_used_in_output_addr[i], regno) | |
4891 || TEST_HARD_REG_BIT (reload_reg_used_in_outaddr_addr[i], regno)) | |
4892 return 0; | |
4893 | |
4894 return 1; | |
4895 | |
4896 case RELOAD_FOR_INSN: | |
4897 for (i = 0; i < reload_n_operands; i++) | |
4898 if (TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno) | |
4899 || TEST_HARD_REG_BIT (reload_reg_used_in_output[i], regno)) | |
4900 return 0; | |
4901 | |
4902 return (! TEST_HARD_REG_BIT (reload_reg_used_in_insn, regno) | |
4903 && ! TEST_HARD_REG_BIT (reload_reg_used_in_op_addr, regno)); | |
4904 | |
4905 case RELOAD_FOR_OTHER_ADDRESS: | |
4906 return ! TEST_HARD_REG_BIT (reload_reg_used_in_other_addr, regno); | |
4907 | |
4908 default: | |
4909 gcc_unreachable (); | |
4910 } | |
4911 } | |
4912 | |
4913 /* Return 1 if the value in reload reg REGNO, as used by a reload | |
4914 needed for the part of the insn specified by OPNUM and TYPE, | |
4915 is still available in REGNO at the end of the insn. | |
4916 | |
4917 We can assume that the reload reg was already tested for availability | |
4918 at the time it is needed, and we should not check this again, | |
4919 in case the reg has already been marked in use. */ | |
4920 | |
4921 static int | |
4922 reload_reg_reaches_end_p (unsigned int regno, int opnum, enum reload_type type) | |
4923 { | |
4924 int i; | |
4925 | |
4926 switch (type) | |
4927 { | |
4928 case RELOAD_OTHER: | |
4929 /* Since a RELOAD_OTHER reload claims the reg for the entire insn, | |
4930 its value must reach the end. */ | |
4931 return 1; | |
4932 | |
4933 /* If this use is for part of the insn, | |
4934 its value reaches if no subsequent part uses the same register. | |
4935 Just like the above function, don't try to do this with lots | |
4936 of fallthroughs. */ | |
4937 | |
4938 case RELOAD_FOR_OTHER_ADDRESS: | |
4939 /* Here we check for everything else, since these don't conflict | |
4940 with anything else and everything comes later. */ | |
4941 | |
4942 for (i = 0; i < reload_n_operands; i++) | |
4943 if (TEST_HARD_REG_BIT (reload_reg_used_in_output_addr[i], regno) | |
4944 || TEST_HARD_REG_BIT (reload_reg_used_in_outaddr_addr[i], regno) | |
4945 || TEST_HARD_REG_BIT (reload_reg_used_in_output[i], regno) | |
4946 || TEST_HARD_REG_BIT (reload_reg_used_in_input_addr[i], regno) | |
4947 || TEST_HARD_REG_BIT (reload_reg_used_in_inpaddr_addr[i], regno) | |
4948 || TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno)) | |
4949 return 0; | |
4950 | |
4951 return (! TEST_HARD_REG_BIT (reload_reg_used_in_op_addr, regno) | |
4952 && ! TEST_HARD_REG_BIT (reload_reg_used_in_op_addr_reload, regno) | |
4953 && ! TEST_HARD_REG_BIT (reload_reg_used_in_insn, regno) | |
4954 && ! TEST_HARD_REG_BIT (reload_reg_used, regno)); | |
4955 | |
4956 case RELOAD_FOR_INPUT_ADDRESS: | |
4957 case RELOAD_FOR_INPADDR_ADDRESS: | |
4958 /* Similar, except that we check only for this and subsequent inputs | |
4959 and the address of only subsequent inputs and we do not need | |
4960 to check for RELOAD_OTHER objects since they are known not to | |
4961 conflict. */ | |
4962 | |
4963 for (i = opnum; i < reload_n_operands; i++) | |
4964 if (TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno)) | |
4965 return 0; | |
4966 | |
4967 for (i = opnum + 1; i < reload_n_operands; i++) | |
4968 if (TEST_HARD_REG_BIT (reload_reg_used_in_input_addr[i], regno) | |
4969 || TEST_HARD_REG_BIT (reload_reg_used_in_inpaddr_addr[i], regno)) | |
4970 return 0; | |
4971 | |
4972 for (i = 0; i < reload_n_operands; i++) | |
4973 if (TEST_HARD_REG_BIT (reload_reg_used_in_output_addr[i], regno) | |
4974 || TEST_HARD_REG_BIT (reload_reg_used_in_outaddr_addr[i], regno) | |
4975 || TEST_HARD_REG_BIT (reload_reg_used_in_output[i], regno)) | |
4976 return 0; | |
4977 | |
4978 if (TEST_HARD_REG_BIT (reload_reg_used_in_op_addr_reload, regno)) | |
4979 return 0; | |
4980 | |
4981 return (!TEST_HARD_REG_BIT (reload_reg_used_in_op_addr, regno) | |
4982 && !TEST_HARD_REG_BIT (reload_reg_used_in_insn, regno) | |
4983 && !TEST_HARD_REG_BIT (reload_reg_used, regno)); | |
4984 | |
4985 case RELOAD_FOR_INPUT: | |
4986 /* Similar to input address, except we start at the next operand for | |
4987 both input and input address and we do not check for | |
4988 RELOAD_FOR_OPERAND_ADDRESS and RELOAD_FOR_INSN since these | |
4989 would conflict. */ | |
4990 | |
4991 for (i = opnum + 1; i < reload_n_operands; i++) | |
4992 if (TEST_HARD_REG_BIT (reload_reg_used_in_input_addr[i], regno) | |
4993 || TEST_HARD_REG_BIT (reload_reg_used_in_inpaddr_addr[i], regno) | |
4994 || TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno)) | |
4995 return 0; | |
4996 | |
4997 /* ... fall through ... */ | |
4998 | |
4999 case RELOAD_FOR_OPERAND_ADDRESS: | |
5000 /* Check outputs and their addresses. */ | |
5001 | |
5002 for (i = 0; i < reload_n_operands; i++) | |
5003 if (TEST_HARD_REG_BIT (reload_reg_used_in_output_addr[i], regno) | |
5004 || TEST_HARD_REG_BIT (reload_reg_used_in_outaddr_addr[i], regno) | |
5005 || TEST_HARD_REG_BIT (reload_reg_used_in_output[i], regno)) | |
5006 return 0; | |
5007 | |
5008 return (!TEST_HARD_REG_BIT (reload_reg_used, regno)); | |
5009 | |
5010 case RELOAD_FOR_OPADDR_ADDR: | |
5011 for (i = 0; i < reload_n_operands; i++) | |
5012 if (TEST_HARD_REG_BIT (reload_reg_used_in_output_addr[i], regno) | |
5013 || TEST_HARD_REG_BIT (reload_reg_used_in_outaddr_addr[i], regno) | |
5014 || TEST_HARD_REG_BIT (reload_reg_used_in_output[i], regno)) | |
5015 return 0; | |
5016 | |
5017 return (!TEST_HARD_REG_BIT (reload_reg_used_in_op_addr, regno) | |
5018 && !TEST_HARD_REG_BIT (reload_reg_used_in_insn, regno) | |
5019 && !TEST_HARD_REG_BIT (reload_reg_used, regno)); | |
5020 | |
5021 case RELOAD_FOR_INSN: | |
5022 /* These conflict with other outputs with RELOAD_OTHER. So | |
5023 we need only check for output addresses. */ | |
5024 | |
5025 opnum = reload_n_operands; | |
5026 | |
5027 /* ... fall through ... */ | |
5028 | |
5029 case RELOAD_FOR_OUTPUT: | |
5030 case RELOAD_FOR_OUTPUT_ADDRESS: | |
5031 case RELOAD_FOR_OUTADDR_ADDRESS: | |
5032 /* We already know these can't conflict with a later output. So the | |
5033 only thing to check are later output addresses. | |
5034 Note that multiple output operands are emitted in reverse order, | |
5035 so the conflicting ones are those with lower indices. */ | |
5036 for (i = 0; i < opnum; i++) | |
5037 if (TEST_HARD_REG_BIT (reload_reg_used_in_output_addr[i], regno) | |
5038 || TEST_HARD_REG_BIT (reload_reg_used_in_outaddr_addr[i], regno)) | |
5039 return 0; | |
5040 | |
5041 return 1; | |
5042 | |
5043 default: | |
5044 gcc_unreachable (); | |
5045 } | |
5046 } | |
5047 | |
5048 /* Like reload_reg_reaches_end_p, but check that the condition holds for | |
5049 every register in the range [REGNO, REGNO + NREGS). */ | |
5050 | |
5051 static bool | |
5052 reload_regs_reach_end_p (unsigned int regno, int nregs, | |
5053 int opnum, enum reload_type type) | |
5054 { | |
5055 int i; | |
5056 | |
5057 for (i = 0; i < nregs; i++) | |
5058 if (!reload_reg_reaches_end_p (regno + i, opnum, type)) | |
5059 return false; | |
5060 return true; | |
5061 } | |
5062 | |
5063 | |
5064 /* Returns whether R1 and R2 are uniquely chained: the value of one | |
5065 is used by the other, and that value is not used by any other | |
5066 reload for this insn. This is used to partially undo the decision | |
5067 made in find_reloads when in the case of multiple | |
5068 RELOAD_FOR_OPERAND_ADDRESS reloads it converts all | |
5069 RELOAD_FOR_OPADDR_ADDR reloads into RELOAD_FOR_OPERAND_ADDRESS | |
5070 reloads. This code tries to avoid the conflict created by that | |
5071 change. It might be cleaner to explicitly keep track of which | |
5072 RELOAD_FOR_OPADDR_ADDR reload is associated with which | |
5073 RELOAD_FOR_OPERAND_ADDRESS reload, rather than to try to detect | |
5074 this after the fact. */ | |
5075 static bool | |
5076 reloads_unique_chain_p (int r1, int r2) | |
5077 { | |
5078 int i; | |
5079 | |
5080 /* We only check input reloads. */ | |
5081 if (! rld[r1].in || ! rld[r2].in) | |
5082 return false; | |
5083 | |
5084 /* Avoid anything with output reloads. */ | |
5085 if (rld[r1].out || rld[r2].out) | |
5086 return false; | |
5087 | |
5088 /* "chained" means one reload is a component of the other reload, | |
5089 not the same as the other reload. */ | |
5090 if (rld[r1].opnum != rld[r2].opnum | |
5091 || rtx_equal_p (rld[r1].in, rld[r2].in) | |
5092 || rld[r1].optional || rld[r2].optional | |
5093 || ! (reg_mentioned_p (rld[r1].in, rld[r2].in) | |
5094 || reg_mentioned_p (rld[r2].in, rld[r1].in))) | |
5095 return false; | |
5096 | |
5097 for (i = 0; i < n_reloads; i ++) | |
5098 /* Look for input reloads that aren't our two */ | |
5099 if (i != r1 && i != r2 && rld[i].in) | |
5100 { | |
5101 /* If our reload is mentioned at all, it isn't a simple chain. */ | |
5102 if (reg_mentioned_p (rld[r1].in, rld[i].in)) | |
5103 return false; | |
5104 } | |
5105 return true; | |
5106 } | |
5107 | |
5108 | |
5109 /* The recursive function change all occurrences of WHAT in *WHERE | |
5110 onto REPL. */ | |
5111 static void | |
5112 substitute (rtx *where, const_rtx what, rtx repl) | |
5113 { | |
5114 const char *fmt; | |
5115 int i; | |
5116 enum rtx_code code; | |
5117 | |
5118 if (*where == 0) | |
5119 return; | |
5120 | |
5121 if (*where == what || rtx_equal_p (*where, what)) | |
5122 { | |
5123 *where = repl; | |
5124 return; | |
5125 } | |
5126 | |
5127 code = GET_CODE (*where); | |
5128 fmt = GET_RTX_FORMAT (code); | |
5129 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
5130 { | |
5131 if (fmt[i] == 'E') | |
5132 { | |
5133 int j; | |
5134 | |
5135 for (j = XVECLEN (*where, i) - 1; j >= 0; j--) | |
5136 substitute (&XVECEXP (*where, i, j), what, repl); | |
5137 } | |
5138 else if (fmt[i] == 'e') | |
5139 substitute (&XEXP (*where, i), what, repl); | |
5140 } | |
5141 } | |
5142 | |
5143 /* The function returns TRUE if chain of reload R1 and R2 (in any | |
5144 order) can be evaluated without usage of intermediate register for | |
5145 the reload containing another reload. It is important to see | |
5146 gen_reload to understand what the function is trying to do. As an | |
5147 example, let us have reload chain | |
5148 | |
5149 r2: const | |
5150 r1: <something> + const | |
5151 | |
5152 and reload R2 got reload reg HR. The function returns true if | |
5153 there is a correct insn HR = HR + <something>. Otherwise, | |
5154 gen_reload will use intermediate register (and this is the reload | |
5155 reg for R1) to reload <something>. | |
5156 | |
5157 We need this function to find a conflict for chain reloads. In our | |
5158 example, if HR = HR + <something> is incorrect insn, then we cannot | |
5159 use HR as a reload register for R2. If we do use it then we get a | |
5160 wrong code: | |
5161 | |
5162 HR = const | |
5163 HR = <something> | |
5164 HR = HR + HR | |
5165 | |
5166 */ | |
5167 static bool | |
5168 gen_reload_chain_without_interm_reg_p (int r1, int r2) | |
5169 { | |
5170 bool result; | |
5171 int regno, n, code; | |
5172 rtx out, in, tem, insn; | |
5173 rtx last = get_last_insn (); | |
5174 | |
5175 /* Make r2 a component of r1. */ | |
5176 if (reg_mentioned_p (rld[r1].in, rld[r2].in)) | |
5177 { | |
5178 n = r1; | |
5179 r1 = r2; | |
5180 r2 = n; | |
5181 } | |
5182 gcc_assert (reg_mentioned_p (rld[r2].in, rld[r1].in)); | |
5183 regno = rld[r1].regno >= 0 ? rld[r1].regno : rld[r2].regno; | |
5184 gcc_assert (regno >= 0); | |
5185 out = gen_rtx_REG (rld[r1].mode, regno); | |
5186 in = copy_rtx (rld[r1].in); | |
5187 substitute (&in, rld[r2].in, gen_rtx_REG (rld[r2].mode, regno)); | |
5188 | |
5189 /* If IN is a paradoxical SUBREG, remove it and try to put the | |
5190 opposite SUBREG on OUT. Likewise for a paradoxical SUBREG on OUT. */ | |
5191 if (GET_CODE (in) == SUBREG | |
5192 && (GET_MODE_SIZE (GET_MODE (in)) | |
5193 > GET_MODE_SIZE (GET_MODE (SUBREG_REG (in)))) | |
5194 && (tem = gen_lowpart_common (GET_MODE (SUBREG_REG (in)), out)) != 0) | |
5195 in = SUBREG_REG (in), out = tem; | |
5196 | |
5197 if (GET_CODE (in) == PLUS | |
5198 && (REG_P (XEXP (in, 0)) | |
5199 || GET_CODE (XEXP (in, 0)) == SUBREG | |
5200 || MEM_P (XEXP (in, 0))) | |
5201 && (REG_P (XEXP (in, 1)) | |
5202 || GET_CODE (XEXP (in, 1)) == SUBREG | |
5203 || CONSTANT_P (XEXP (in, 1)) | |
5204 || MEM_P (XEXP (in, 1)))) | |
5205 { | |
5206 insn = emit_insn (gen_rtx_SET (VOIDmode, out, in)); | |
5207 code = recog_memoized (insn); | |
5208 result = false; | |
5209 | |
5210 if (code >= 0) | |
5211 { | |
5212 extract_insn (insn); | |
5213 /* We want constrain operands to treat this insn strictly in | |
5214 its validity determination, i.e., the way it would after | |
5215 reload has completed. */ | |
5216 result = constrain_operands (1); | |
5217 } | |
5218 | |
5219 delete_insns_since (last); | |
5220 return result; | |
5221 } | |
5222 | |
5223 /* It looks like other cases in gen_reload are not possible for | |
5224 chain reloads or do need an intermediate hard registers. */ | |
5225 return true; | |
5226 } | |
5227 | |
5228 /* Return 1 if the reloads denoted by R1 and R2 cannot share a register. | |
5229 Return 0 otherwise. | |
5230 | |
5231 This function uses the same algorithm as reload_reg_free_p above. */ | |
5232 | |
5233 static int | |
5234 reloads_conflict (int r1, int r2) | |
5235 { | |
5236 enum reload_type r1_type = rld[r1].when_needed; | |
5237 enum reload_type r2_type = rld[r2].when_needed; | |
5238 int r1_opnum = rld[r1].opnum; | |
5239 int r2_opnum = rld[r2].opnum; | |
5240 | |
5241 /* RELOAD_OTHER conflicts with everything. */ | |
5242 if (r2_type == RELOAD_OTHER) | |
5243 return 1; | |
5244 | |
5245 /* Otherwise, check conflicts differently for each type. */ | |
5246 | |
5247 switch (r1_type) | |
5248 { | |
5249 case RELOAD_FOR_INPUT: | |
5250 return (r2_type == RELOAD_FOR_INSN | |
5251 || r2_type == RELOAD_FOR_OPERAND_ADDRESS | |
5252 || r2_type == RELOAD_FOR_OPADDR_ADDR | |
5253 || r2_type == RELOAD_FOR_INPUT | |
5254 || ((r2_type == RELOAD_FOR_INPUT_ADDRESS | |
5255 || r2_type == RELOAD_FOR_INPADDR_ADDRESS) | |
5256 && r2_opnum > r1_opnum)); | |
5257 | |
5258 case RELOAD_FOR_INPUT_ADDRESS: | |
5259 return ((r2_type == RELOAD_FOR_INPUT_ADDRESS && r1_opnum == r2_opnum) | |
5260 || (r2_type == RELOAD_FOR_INPUT && r2_opnum < r1_opnum)); | |
5261 | |
5262 case RELOAD_FOR_INPADDR_ADDRESS: | |
5263 return ((r2_type == RELOAD_FOR_INPADDR_ADDRESS && r1_opnum == r2_opnum) | |
5264 || (r2_type == RELOAD_FOR_INPUT && r2_opnum < r1_opnum)); | |
5265 | |
5266 case RELOAD_FOR_OUTPUT_ADDRESS: | |
5267 return ((r2_type == RELOAD_FOR_OUTPUT_ADDRESS && r2_opnum == r1_opnum) | |
5268 || (r2_type == RELOAD_FOR_OUTPUT && r2_opnum <= r1_opnum)); | |
5269 | |
5270 case RELOAD_FOR_OUTADDR_ADDRESS: | |
5271 return ((r2_type == RELOAD_FOR_OUTADDR_ADDRESS && r2_opnum == r1_opnum) | |
5272 || (r2_type == RELOAD_FOR_OUTPUT && r2_opnum <= r1_opnum)); | |
5273 | |
5274 case RELOAD_FOR_OPERAND_ADDRESS: | |
5275 return (r2_type == RELOAD_FOR_INPUT || r2_type == RELOAD_FOR_INSN | |
5276 || (r2_type == RELOAD_FOR_OPERAND_ADDRESS | |
5277 && (!reloads_unique_chain_p (r1, r2) | |
5278 || !gen_reload_chain_without_interm_reg_p (r1, r2)))); | |
5279 | |
5280 case RELOAD_FOR_OPADDR_ADDR: | |
5281 return (r2_type == RELOAD_FOR_INPUT | |
5282 || r2_type == RELOAD_FOR_OPADDR_ADDR); | |
5283 | |
5284 case RELOAD_FOR_OUTPUT: | |
5285 return (r2_type == RELOAD_FOR_INSN || r2_type == RELOAD_FOR_OUTPUT | |
5286 || ((r2_type == RELOAD_FOR_OUTPUT_ADDRESS | |
5287 || r2_type == RELOAD_FOR_OUTADDR_ADDRESS) | |
5288 && r2_opnum >= r1_opnum)); | |
5289 | |
5290 case RELOAD_FOR_INSN: | |
5291 return (r2_type == RELOAD_FOR_INPUT || r2_type == RELOAD_FOR_OUTPUT | |
5292 || r2_type == RELOAD_FOR_INSN | |
5293 || r2_type == RELOAD_FOR_OPERAND_ADDRESS); | |
5294 | |
5295 case RELOAD_FOR_OTHER_ADDRESS: | |
5296 return r2_type == RELOAD_FOR_OTHER_ADDRESS; | |
5297 | |
5298 case RELOAD_OTHER: | |
5299 return 1; | |
5300 | |
5301 default: | |
5302 gcc_unreachable (); | |
5303 } | |
5304 } | |
5305 | |
5306 /* Indexed by reload number, 1 if incoming value | |
5307 inherited from previous insns. */ | |
5308 static char reload_inherited[MAX_RELOADS]; | |
5309 | |
5310 /* For an inherited reload, this is the insn the reload was inherited from, | |
5311 if we know it. Otherwise, this is 0. */ | |
5312 static rtx reload_inheritance_insn[MAX_RELOADS]; | |
5313 | |
5314 /* If nonzero, this is a place to get the value of the reload, | |
5315 rather than using reload_in. */ | |
5316 static rtx reload_override_in[MAX_RELOADS]; | |
5317 | |
5318 /* For each reload, the hard register number of the register used, | |
5319 or -1 if we did not need a register for this reload. */ | |
5320 static int reload_spill_index[MAX_RELOADS]; | |
5321 | |
5322 /* Index X is the value of rld[X].reg_rtx, adjusted for the input mode. */ | |
5323 static rtx reload_reg_rtx_for_input[MAX_RELOADS]; | |
5324 | |
5325 /* Index X is the value of rld[X].reg_rtx, adjusted for the output mode. */ | |
5326 static rtx reload_reg_rtx_for_output[MAX_RELOADS]; | |
5327 | |
5328 /* Subroutine of free_for_value_p, used to check a single register. | |
5329 START_REGNO is the starting regno of the full reload register | |
5330 (possibly comprising multiple hard registers) that we are considering. */ | |
5331 | |
5332 static int | |
5333 reload_reg_free_for_value_p (int start_regno, int regno, int opnum, | |
5334 enum reload_type type, rtx value, rtx out, | |
5335 int reloadnum, int ignore_address_reloads) | |
5336 { | |
5337 int time1; | |
5338 /* Set if we see an input reload that must not share its reload register | |
5339 with any new earlyclobber, but might otherwise share the reload | |
5340 register with an output or input-output reload. */ | |
5341 int check_earlyclobber = 0; | |
5342 int i; | |
5343 int copy = 0; | |
5344 | |
5345 if (TEST_HARD_REG_BIT (reload_reg_unavailable, regno)) | |
5346 return 0; | |
5347 | |
5348 if (out == const0_rtx) | |
5349 { | |
5350 copy = 1; | |
5351 out = NULL_RTX; | |
5352 } | |
5353 | |
5354 /* We use some pseudo 'time' value to check if the lifetimes of the | |
5355 new register use would overlap with the one of a previous reload | |
5356 that is not read-only or uses a different value. | |
5357 The 'time' used doesn't have to be linear in any shape or form, just | |
5358 monotonic. | |
5359 Some reload types use different 'buckets' for each operand. | |
5360 So there are MAX_RECOG_OPERANDS different time values for each | |
5361 such reload type. | |
5362 We compute TIME1 as the time when the register for the prospective | |
5363 new reload ceases to be live, and TIME2 for each existing | |
5364 reload as the time when that the reload register of that reload | |
5365 becomes live. | |
5366 Where there is little to be gained by exact lifetime calculations, | |
5367 we just make conservative assumptions, i.e. a longer lifetime; | |
5368 this is done in the 'default:' cases. */ | |
5369 switch (type) | |
5370 { | |
5371 case RELOAD_FOR_OTHER_ADDRESS: | |
5372 /* RELOAD_FOR_OTHER_ADDRESS conflicts with RELOAD_OTHER reloads. */ | |
5373 time1 = copy ? 0 : 1; | |
5374 break; | |
5375 case RELOAD_OTHER: | |
5376 time1 = copy ? 1 : MAX_RECOG_OPERANDS * 5 + 5; | |
5377 break; | |
5378 /* For each input, we may have a sequence of RELOAD_FOR_INPADDR_ADDRESS, | |
5379 RELOAD_FOR_INPUT_ADDRESS and RELOAD_FOR_INPUT. By adding 0 / 1 / 2 , | |
5380 respectively, to the time values for these, we get distinct time | |
5381 values. To get distinct time values for each operand, we have to | |
5382 multiply opnum by at least three. We round that up to four because | |
5383 multiply by four is often cheaper. */ | |
5384 case RELOAD_FOR_INPADDR_ADDRESS: | |
5385 time1 = opnum * 4 + 2; | |
5386 break; | |
5387 case RELOAD_FOR_INPUT_ADDRESS: | |
5388 time1 = opnum * 4 + 3; | |
5389 break; | |
5390 case RELOAD_FOR_INPUT: | |
5391 /* All RELOAD_FOR_INPUT reloads remain live till the instruction | |
5392 executes (inclusive). */ | |
5393 time1 = copy ? opnum * 4 + 4 : MAX_RECOG_OPERANDS * 4 + 3; | |
5394 break; | |
5395 case RELOAD_FOR_OPADDR_ADDR: | |
5396 /* opnum * 4 + 4 | |
5397 <= (MAX_RECOG_OPERANDS - 1) * 4 + 4 == MAX_RECOG_OPERANDS * 4 */ | |
5398 time1 = MAX_RECOG_OPERANDS * 4 + 1; | |
5399 break; | |
5400 case RELOAD_FOR_OPERAND_ADDRESS: | |
5401 /* RELOAD_FOR_OPERAND_ADDRESS reloads are live even while the insn | |
5402 is executed. */ | |
5403 time1 = copy ? MAX_RECOG_OPERANDS * 4 + 2 : MAX_RECOG_OPERANDS * 4 + 3; | |
5404 break; | |
5405 case RELOAD_FOR_OUTADDR_ADDRESS: | |
5406 time1 = MAX_RECOG_OPERANDS * 4 + 4 + opnum; | |
5407 break; | |
5408 case RELOAD_FOR_OUTPUT_ADDRESS: | |
5409 time1 = MAX_RECOG_OPERANDS * 4 + 5 + opnum; | |
5410 break; | |
5411 default: | |
5412 time1 = MAX_RECOG_OPERANDS * 5 + 5; | |
5413 } | |
5414 | |
5415 for (i = 0; i < n_reloads; i++) | |
5416 { | |
5417 rtx reg = rld[i].reg_rtx; | |
5418 if (reg && REG_P (reg) | |
5419 && ((unsigned) regno - true_regnum (reg) | |
5420 <= hard_regno_nregs[REGNO (reg)][GET_MODE (reg)] - (unsigned) 1) | |
5421 && i != reloadnum) | |
5422 { | |
5423 rtx other_input = rld[i].in; | |
5424 | |
5425 /* If the other reload loads the same input value, that | |
5426 will not cause a conflict only if it's loading it into | |
5427 the same register. */ | |
5428 if (true_regnum (reg) != start_regno) | |
5429 other_input = NULL_RTX; | |
5430 if (! other_input || ! rtx_equal_p (other_input, value) | |
5431 || rld[i].out || out) | |
5432 { | |
5433 int time2; | |
5434 switch (rld[i].when_needed) | |
5435 { | |
5436 case RELOAD_FOR_OTHER_ADDRESS: | |
5437 time2 = 0; | |
5438 break; | |
5439 case RELOAD_FOR_INPADDR_ADDRESS: | |
5440 /* find_reloads makes sure that a | |
5441 RELOAD_FOR_{INP,OP,OUT}ADDR_ADDRESS reload is only used | |
5442 by at most one - the first - | |
5443 RELOAD_FOR_{INPUT,OPERAND,OUTPUT}_ADDRESS . If the | |
5444 address reload is inherited, the address address reload | |
5445 goes away, so we can ignore this conflict. */ | |
5446 if (type == RELOAD_FOR_INPUT_ADDRESS && reloadnum == i + 1 | |
5447 && ignore_address_reloads | |
5448 /* Unless the RELOAD_FOR_INPUT is an auto_inc expression. | |
5449 Then the address address is still needed to store | |
5450 back the new address. */ | |
5451 && ! rld[reloadnum].out) | |
5452 continue; | |
5453 /* Likewise, if a RELOAD_FOR_INPUT can inherit a value, its | |
5454 RELOAD_FOR_INPUT_ADDRESS / RELOAD_FOR_INPADDR_ADDRESS | |
5455 reloads go away. */ | |
5456 if (type == RELOAD_FOR_INPUT && opnum == rld[i].opnum | |
5457 && ignore_address_reloads | |
5458 /* Unless we are reloading an auto_inc expression. */ | |
5459 && ! rld[reloadnum].out) | |
5460 continue; | |
5461 time2 = rld[i].opnum * 4 + 2; | |
5462 break; | |
5463 case RELOAD_FOR_INPUT_ADDRESS: | |
5464 if (type == RELOAD_FOR_INPUT && opnum == rld[i].opnum | |
5465 && ignore_address_reloads | |
5466 && ! rld[reloadnum].out) | |
5467 continue; | |
5468 time2 = rld[i].opnum * 4 + 3; | |
5469 break; | |
5470 case RELOAD_FOR_INPUT: | |
5471 time2 = rld[i].opnum * 4 + 4; | |
5472 check_earlyclobber = 1; | |
5473 break; | |
5474 /* rld[i].opnum * 4 + 4 <= (MAX_RECOG_OPERAND - 1) * 4 + 4 | |
5475 == MAX_RECOG_OPERAND * 4 */ | |
5476 case RELOAD_FOR_OPADDR_ADDR: | |
5477 if (type == RELOAD_FOR_OPERAND_ADDRESS && reloadnum == i + 1 | |
5478 && ignore_address_reloads | |
5479 && ! rld[reloadnum].out) | |
5480 continue; | |
5481 time2 = MAX_RECOG_OPERANDS * 4 + 1; | |
5482 break; | |
5483 case RELOAD_FOR_OPERAND_ADDRESS: | |
5484 time2 = MAX_RECOG_OPERANDS * 4 + 2; | |
5485 check_earlyclobber = 1; | |
5486 break; | |
5487 case RELOAD_FOR_INSN: | |
5488 time2 = MAX_RECOG_OPERANDS * 4 + 3; | |
5489 break; | |
5490 case RELOAD_FOR_OUTPUT: | |
5491 /* All RELOAD_FOR_OUTPUT reloads become live just after the | |
5492 instruction is executed. */ | |
5493 time2 = MAX_RECOG_OPERANDS * 4 + 4; | |
5494 break; | |
5495 /* The first RELOAD_FOR_OUTADDR_ADDRESS reload conflicts with | |
5496 the RELOAD_FOR_OUTPUT reloads, so assign it the same time | |
5497 value. */ | |
5498 case RELOAD_FOR_OUTADDR_ADDRESS: | |
5499 if (type == RELOAD_FOR_OUTPUT_ADDRESS && reloadnum == i + 1 | |
5500 && ignore_address_reloads | |
5501 && ! rld[reloadnum].out) | |
5502 continue; | |
5503 time2 = MAX_RECOG_OPERANDS * 4 + 4 + rld[i].opnum; | |
5504 break; | |
5505 case RELOAD_FOR_OUTPUT_ADDRESS: | |
5506 time2 = MAX_RECOG_OPERANDS * 4 + 5 + rld[i].opnum; | |
5507 break; | |
5508 case RELOAD_OTHER: | |
5509 /* If there is no conflict in the input part, handle this | |
5510 like an output reload. */ | |
5511 if (! rld[i].in || rtx_equal_p (other_input, value)) | |
5512 { | |
5513 time2 = MAX_RECOG_OPERANDS * 4 + 4; | |
5514 /* Earlyclobbered outputs must conflict with inputs. */ | |
5515 if (earlyclobber_operand_p (rld[i].out)) | |
5516 time2 = MAX_RECOG_OPERANDS * 4 + 3; | |
5517 | |
5518 break; | |
5519 } | |
5520 time2 = 1; | |
5521 /* RELOAD_OTHER might be live beyond instruction execution, | |
5522 but this is not obvious when we set time2 = 1. So check | |
5523 here if there might be a problem with the new reload | |
5524 clobbering the register used by the RELOAD_OTHER. */ | |
5525 if (out) | |
5526 return 0; | |
5527 break; | |
5528 default: | |
5529 return 0; | |
5530 } | |
5531 if ((time1 >= time2 | |
5532 && (! rld[i].in || rld[i].out | |
5533 || ! rtx_equal_p (other_input, value))) | |
5534 || (out && rld[reloadnum].out_reg | |
5535 && time2 >= MAX_RECOG_OPERANDS * 4 + 3)) | |
5536 return 0; | |
5537 } | |
5538 } | |
5539 } | |
5540 | |
5541 /* Earlyclobbered outputs must conflict with inputs. */ | |
5542 if (check_earlyclobber && out && earlyclobber_operand_p (out)) | |
5543 return 0; | |
5544 | |
5545 return 1; | |
5546 } | |
5547 | |
5548 /* Return 1 if the value in reload reg REGNO, as used by a reload | |
5549 needed for the part of the insn specified by OPNUM and TYPE, | |
5550 may be used to load VALUE into it. | |
5551 | |
5552 MODE is the mode in which the register is used, this is needed to | |
5553 determine how many hard regs to test. | |
5554 | |
5555 Other read-only reloads with the same value do not conflict | |
5556 unless OUT is nonzero and these other reloads have to live while | |
5557 output reloads live. | |
5558 If OUT is CONST0_RTX, this is a special case: it means that the | |
5559 test should not be for using register REGNO as reload register, but | |
5560 for copying from register REGNO into the reload register. | |
5561 | |
5562 RELOADNUM is the number of the reload we want to load this value for; | |
5563 a reload does not conflict with itself. | |
5564 | |
5565 When IGNORE_ADDRESS_RELOADS is set, we can not have conflicts with | |
5566 reloads that load an address for the very reload we are considering. | |
5567 | |
5568 The caller has to make sure that there is no conflict with the return | |
5569 register. */ | |
5570 | |
5571 static int | |
5572 free_for_value_p (int regno, enum machine_mode mode, int opnum, | |
5573 enum reload_type type, rtx value, rtx out, int reloadnum, | |
5574 int ignore_address_reloads) | |
5575 { | |
5576 int nregs = hard_regno_nregs[regno][mode]; | |
5577 while (nregs-- > 0) | |
5578 if (! reload_reg_free_for_value_p (regno, regno + nregs, opnum, type, | |
5579 value, out, reloadnum, | |
5580 ignore_address_reloads)) | |
5581 return 0; | |
5582 return 1; | |
5583 } | |
5584 | |
5585 /* Return nonzero if the rtx X is invariant over the current function. */ | |
5586 /* ??? Actually, the places where we use this expect exactly what is | |
5587 tested here, and not everything that is function invariant. In | |
5588 particular, the frame pointer and arg pointer are special cased; | |
5589 pic_offset_table_rtx is not, and we must not spill these things to | |
5590 memory. */ | |
5591 | |
5592 int | |
5593 function_invariant_p (const_rtx x) | |
5594 { | |
5595 if (CONSTANT_P (x)) | |
5596 return 1; | |
5597 if (x == frame_pointer_rtx || x == arg_pointer_rtx) | |
5598 return 1; | |
5599 if (GET_CODE (x) == PLUS | |
5600 && (XEXP (x, 0) == frame_pointer_rtx || XEXP (x, 0) == arg_pointer_rtx) | |
5601 && CONSTANT_P (XEXP (x, 1))) | |
5602 return 1; | |
5603 return 0; | |
5604 } | |
5605 | |
5606 /* Determine whether the reload reg X overlaps any rtx'es used for | |
5607 overriding inheritance. Return nonzero if so. */ | |
5608 | |
5609 static int | |
5610 conflicts_with_override (rtx x) | |
5611 { | |
5612 int i; | |
5613 for (i = 0; i < n_reloads; i++) | |
5614 if (reload_override_in[i] | |
5615 && reg_overlap_mentioned_p (x, reload_override_in[i])) | |
5616 return 1; | |
5617 return 0; | |
5618 } | |
5619 | |
5620 /* Give an error message saying we failed to find a reload for INSN, | |
5621 and clear out reload R. */ | |
5622 static void | |
5623 failed_reload (rtx insn, int r) | |
5624 { | |
5625 if (asm_noperands (PATTERN (insn)) < 0) | |
5626 /* It's the compiler's fault. */ | |
5627 fatal_insn ("could not find a spill register", insn); | |
5628 | |
5629 /* It's the user's fault; the operand's mode and constraint | |
5630 don't match. Disable this reload so we don't crash in final. */ | |
5631 error_for_asm (insn, | |
5632 "%<asm%> operand constraint incompatible with operand size"); | |
5633 rld[r].in = 0; | |
5634 rld[r].out = 0; | |
5635 rld[r].reg_rtx = 0; | |
5636 rld[r].optional = 1; | |
5637 rld[r].secondary_p = 1; | |
5638 } | |
5639 | |
5640 /* I is the index in SPILL_REG_RTX of the reload register we are to allocate | |
5641 for reload R. If it's valid, get an rtx for it. Return nonzero if | |
5642 successful. */ | |
5643 static int | |
5644 set_reload_reg (int i, int r) | |
5645 { | |
5646 int regno; | |
5647 rtx reg = spill_reg_rtx[i]; | |
5648 | |
5649 if (reg == 0 || GET_MODE (reg) != rld[r].mode) | |
5650 spill_reg_rtx[i] = reg | |
5651 = gen_rtx_REG (rld[r].mode, spill_regs[i]); | |
5652 | |
5653 regno = true_regnum (reg); | |
5654 | |
5655 /* Detect when the reload reg can't hold the reload mode. | |
5656 This used to be one `if', but Sequent compiler can't handle that. */ | |
5657 if (HARD_REGNO_MODE_OK (regno, rld[r].mode)) | |
5658 { | |
5659 enum machine_mode test_mode = VOIDmode; | |
5660 if (rld[r].in) | |
5661 test_mode = GET_MODE (rld[r].in); | |
5662 /* If rld[r].in has VOIDmode, it means we will load it | |
5663 in whatever mode the reload reg has: to wit, rld[r].mode. | |
5664 We have already tested that for validity. */ | |
5665 /* Aside from that, we need to test that the expressions | |
5666 to reload from or into have modes which are valid for this | |
5667 reload register. Otherwise the reload insns would be invalid. */ | |
5668 if (! (rld[r].in != 0 && test_mode != VOIDmode | |
5669 && ! HARD_REGNO_MODE_OK (regno, test_mode))) | |
5670 if (! (rld[r].out != 0 | |
5671 && ! HARD_REGNO_MODE_OK (regno, GET_MODE (rld[r].out)))) | |
5672 { | |
5673 /* The reg is OK. */ | |
5674 last_spill_reg = i; | |
5675 | |
5676 /* Mark as in use for this insn the reload regs we use | |
5677 for this. */ | |
5678 mark_reload_reg_in_use (spill_regs[i], rld[r].opnum, | |
5679 rld[r].when_needed, rld[r].mode); | |
5680 | |
5681 rld[r].reg_rtx = reg; | |
5682 reload_spill_index[r] = spill_regs[i]; | |
5683 return 1; | |
5684 } | |
5685 } | |
5686 return 0; | |
5687 } | |
5688 | |
5689 /* Find a spill register to use as a reload register for reload R. | |
5690 LAST_RELOAD is nonzero if this is the last reload for the insn being | |
5691 processed. | |
5692 | |
5693 Set rld[R].reg_rtx to the register allocated. | |
5694 | |
5695 We return 1 if successful, or 0 if we couldn't find a spill reg and | |
5696 we didn't change anything. */ | |
5697 | |
5698 static int | |
5699 allocate_reload_reg (struct insn_chain *chain ATTRIBUTE_UNUSED, int r, | |
5700 int last_reload) | |
5701 { | |
5702 int i, pass, count; | |
5703 | |
5704 /* If we put this reload ahead, thinking it is a group, | |
5705 then insist on finding a group. Otherwise we can grab a | |
5706 reg that some other reload needs. | |
5707 (That can happen when we have a 68000 DATA_OR_FP_REG | |
5708 which is a group of data regs or one fp reg.) | |
5709 We need not be so restrictive if there are no more reloads | |
5710 for this insn. | |
5711 | |
5712 ??? Really it would be nicer to have smarter handling | |
5713 for that kind of reg class, where a problem like this is normal. | |
5714 Perhaps those classes should be avoided for reloading | |
5715 by use of more alternatives. */ | |
5716 | |
5717 int force_group = rld[r].nregs > 1 && ! last_reload; | |
5718 | |
5719 /* If we want a single register and haven't yet found one, | |
5720 take any reg in the right class and not in use. | |
5721 If we want a consecutive group, here is where we look for it. | |
5722 | |
5723 We use two passes so we can first look for reload regs to | |
5724 reuse, which are already in use for other reloads in this insn, | |
5725 and only then use additional registers. | |
5726 I think that maximizing reuse is needed to make sure we don't | |
5727 run out of reload regs. Suppose we have three reloads, and | |
5728 reloads A and B can share regs. These need two regs. | |
5729 Suppose A and B are given different regs. | |
5730 That leaves none for C. */ | |
5731 for (pass = 0; pass < 2; pass++) | |
5732 { | |
5733 /* I is the index in spill_regs. | |
5734 We advance it round-robin between insns to use all spill regs | |
5735 equally, so that inherited reloads have a chance | |
5736 of leapfrogging each other. */ | |
5737 | |
5738 i = last_spill_reg; | |
5739 | |
5740 for (count = 0; count < n_spills; count++) | |
5741 { | |
5742 int rclass = (int) rld[r].rclass; | |
5743 int regnum; | |
5744 | |
5745 i++; | |
5746 if (i >= n_spills) | |
5747 i -= n_spills; | |
5748 regnum = spill_regs[i]; | |
5749 | |
5750 if ((reload_reg_free_p (regnum, rld[r].opnum, | |
5751 rld[r].when_needed) | |
5752 || (rld[r].in | |
5753 /* We check reload_reg_used to make sure we | |
5754 don't clobber the return register. */ | |
5755 && ! TEST_HARD_REG_BIT (reload_reg_used, regnum) | |
5756 && free_for_value_p (regnum, rld[r].mode, rld[r].opnum, | |
5757 rld[r].when_needed, rld[r].in, | |
5758 rld[r].out, r, 1))) | |
5759 && TEST_HARD_REG_BIT (reg_class_contents[rclass], regnum) | |
5760 && HARD_REGNO_MODE_OK (regnum, rld[r].mode) | |
5761 /* Look first for regs to share, then for unshared. But | |
5762 don't share regs used for inherited reloads; they are | |
5763 the ones we want to preserve. */ | |
5764 && (pass | |
5765 || (TEST_HARD_REG_BIT (reload_reg_used_at_all, | |
5766 regnum) | |
5767 && ! TEST_HARD_REG_BIT (reload_reg_used_for_inherit, | |
5768 regnum)))) | |
5769 { | |
5770 int nr = hard_regno_nregs[regnum][rld[r].mode]; | |
5771 /* Avoid the problem where spilling a GENERAL_OR_FP_REG | |
5772 (on 68000) got us two FP regs. If NR is 1, | |
5773 we would reject both of them. */ | |
5774 if (force_group) | |
5775 nr = rld[r].nregs; | |
5776 /* If we need only one reg, we have already won. */ | |
5777 if (nr == 1) | |
5778 { | |
5779 /* But reject a single reg if we demand a group. */ | |
5780 if (force_group) | |
5781 continue; | |
5782 break; | |
5783 } | |
5784 /* Otherwise check that as many consecutive regs as we need | |
5785 are available here. */ | |
5786 while (nr > 1) | |
5787 { | |
5788 int regno = regnum + nr - 1; | |
5789 if (!(TEST_HARD_REG_BIT (reg_class_contents[rclass], regno) | |
5790 && spill_reg_order[regno] >= 0 | |
5791 && reload_reg_free_p (regno, rld[r].opnum, | |
5792 rld[r].when_needed))) | |
5793 break; | |
5794 nr--; | |
5795 } | |
5796 if (nr == 1) | |
5797 break; | |
5798 } | |
5799 } | |
5800 | |
5801 /* If we found something on pass 1, omit pass 2. */ | |
5802 if (count < n_spills) | |
5803 break; | |
5804 } | |
5805 | |
5806 /* We should have found a spill register by now. */ | |
5807 if (count >= n_spills) | |
5808 return 0; | |
5809 | |
5810 /* I is the index in SPILL_REG_RTX of the reload register we are to | |
5811 allocate. Get an rtx for it and find its register number. */ | |
5812 | |
5813 return set_reload_reg (i, r); | |
5814 } | |
5815 | |
5816 /* Initialize all the tables needed to allocate reload registers. | |
5817 CHAIN is the insn currently being processed; SAVE_RELOAD_REG_RTX | |
5818 is the array we use to restore the reg_rtx field for every reload. */ | |
5819 | |
5820 static void | |
5821 choose_reload_regs_init (struct insn_chain *chain, rtx *save_reload_reg_rtx) | |
5822 { | |
5823 int i; | |
5824 | |
5825 for (i = 0; i < n_reloads; i++) | |
5826 rld[i].reg_rtx = save_reload_reg_rtx[i]; | |
5827 | |
5828 memset (reload_inherited, 0, MAX_RELOADS); | |
5829 memset (reload_inheritance_insn, 0, MAX_RELOADS * sizeof (rtx)); | |
5830 memset (reload_override_in, 0, MAX_RELOADS * sizeof (rtx)); | |
5831 | |
5832 CLEAR_HARD_REG_SET (reload_reg_used); | |
5833 CLEAR_HARD_REG_SET (reload_reg_used_at_all); | |
5834 CLEAR_HARD_REG_SET (reload_reg_used_in_op_addr); | |
5835 CLEAR_HARD_REG_SET (reload_reg_used_in_op_addr_reload); | |
5836 CLEAR_HARD_REG_SET (reload_reg_used_in_insn); | |
5837 CLEAR_HARD_REG_SET (reload_reg_used_in_other_addr); | |
5838 | |
5839 CLEAR_HARD_REG_SET (reg_used_in_insn); | |
5840 { | |
5841 HARD_REG_SET tmp; | |
5842 REG_SET_TO_HARD_REG_SET (tmp, &chain->live_throughout); | |
5843 IOR_HARD_REG_SET (reg_used_in_insn, tmp); | |
5844 REG_SET_TO_HARD_REG_SET (tmp, &chain->dead_or_set); | |
5845 IOR_HARD_REG_SET (reg_used_in_insn, tmp); | |
5846 compute_use_by_pseudos (®_used_in_insn, &chain->live_throughout); | |
5847 compute_use_by_pseudos (®_used_in_insn, &chain->dead_or_set); | |
5848 } | |
5849 | |
5850 for (i = 0; i < reload_n_operands; i++) | |
5851 { | |
5852 CLEAR_HARD_REG_SET (reload_reg_used_in_output[i]); | |
5853 CLEAR_HARD_REG_SET (reload_reg_used_in_input[i]); | |
5854 CLEAR_HARD_REG_SET (reload_reg_used_in_input_addr[i]); | |
5855 CLEAR_HARD_REG_SET (reload_reg_used_in_inpaddr_addr[i]); | |
5856 CLEAR_HARD_REG_SET (reload_reg_used_in_output_addr[i]); | |
5857 CLEAR_HARD_REG_SET (reload_reg_used_in_outaddr_addr[i]); | |
5858 } | |
5859 | |
5860 COMPL_HARD_REG_SET (reload_reg_unavailable, chain->used_spill_regs); | |
5861 | |
5862 CLEAR_HARD_REG_SET (reload_reg_used_for_inherit); | |
5863 | |
5864 for (i = 0; i < n_reloads; i++) | |
5865 /* If we have already decided to use a certain register, | |
5866 don't use it in another way. */ | |
5867 if (rld[i].reg_rtx) | |
5868 mark_reload_reg_in_use (REGNO (rld[i].reg_rtx), rld[i].opnum, | |
5869 rld[i].when_needed, rld[i].mode); | |
5870 } | |
5871 | |
5872 /* Assign hard reg targets for the pseudo-registers we must reload | |
5873 into hard regs for this insn. | |
5874 Also output the instructions to copy them in and out of the hard regs. | |
5875 | |
5876 For machines with register classes, we are responsible for | |
5877 finding a reload reg in the proper class. */ | |
5878 | |
5879 static void | |
5880 choose_reload_regs (struct insn_chain *chain) | |
5881 { | |
5882 rtx insn = chain->insn; | |
5883 int i, j; | |
5884 unsigned int max_group_size = 1; | |
5885 enum reg_class group_class = NO_REGS; | |
5886 int pass, win, inheritance; | |
5887 | |
5888 rtx save_reload_reg_rtx[MAX_RELOADS]; | |
5889 | |
5890 /* In order to be certain of getting the registers we need, | |
5891 we must sort the reloads into order of increasing register class. | |
5892 Then our grabbing of reload registers will parallel the process | |
5893 that provided the reload registers. | |
5894 | |
5895 Also note whether any of the reloads wants a consecutive group of regs. | |
5896 If so, record the maximum size of the group desired and what | |
5897 register class contains all the groups needed by this insn. */ | |
5898 | |
5899 for (j = 0; j < n_reloads; j++) | |
5900 { | |
5901 reload_order[j] = j; | |
5902 if (rld[j].reg_rtx != NULL_RTX) | |
5903 { | |
5904 gcc_assert (REG_P (rld[j].reg_rtx) | |
5905 && HARD_REGISTER_P (rld[j].reg_rtx)); | |
5906 reload_spill_index[j] = REGNO (rld[j].reg_rtx); | |
5907 } | |
5908 else | |
5909 reload_spill_index[j] = -1; | |
5910 | |
5911 if (rld[j].nregs > 1) | |
5912 { | |
5913 max_group_size = MAX (rld[j].nregs, max_group_size); | |
5914 group_class | |
5915 = reg_class_superunion[(int) rld[j].rclass][(int) group_class]; | |
5916 } | |
5917 | |
5918 save_reload_reg_rtx[j] = rld[j].reg_rtx; | |
5919 } | |
5920 | |
5921 if (n_reloads > 1) | |
5922 qsort (reload_order, n_reloads, sizeof (short), reload_reg_class_lower); | |
5923 | |
5924 /* If -O, try first with inheritance, then turning it off. | |
5925 If not -O, don't do inheritance. | |
5926 Using inheritance when not optimizing leads to paradoxes | |
5927 with fp on the 68k: fp numbers (not NaNs) fail to be equal to themselves | |
5928 because one side of the comparison might be inherited. */ | |
5929 win = 0; | |
5930 for (inheritance = optimize > 0; inheritance >= 0; inheritance--) | |
5931 { | |
5932 choose_reload_regs_init (chain, save_reload_reg_rtx); | |
5933 | |
5934 /* Process the reloads in order of preference just found. | |
5935 Beyond this point, subregs can be found in reload_reg_rtx. | |
5936 | |
5937 This used to look for an existing reloaded home for all of the | |
5938 reloads, and only then perform any new reloads. But that could lose | |
5939 if the reloads were done out of reg-class order because a later | |
5940 reload with a looser constraint might have an old home in a register | |
5941 needed by an earlier reload with a tighter constraint. | |
5942 | |
5943 To solve this, we make two passes over the reloads, in the order | |
5944 described above. In the first pass we try to inherit a reload | |
5945 from a previous insn. If there is a later reload that needs a | |
5946 class that is a proper subset of the class being processed, we must | |
5947 also allocate a spill register during the first pass. | |
5948 | |
5949 Then make a second pass over the reloads to allocate any reloads | |
5950 that haven't been given registers yet. */ | |
5951 | |
5952 for (j = 0; j < n_reloads; j++) | |
5953 { | |
5954 int r = reload_order[j]; | |
5955 rtx search_equiv = NULL_RTX; | |
5956 | |
5957 /* Ignore reloads that got marked inoperative. */ | |
5958 if (rld[r].out == 0 && rld[r].in == 0 | |
5959 && ! rld[r].secondary_p) | |
5960 continue; | |
5961 | |
5962 /* If find_reloads chose to use reload_in or reload_out as a reload | |
5963 register, we don't need to chose one. Otherwise, try even if it | |
5964 found one since we might save an insn if we find the value lying | |
5965 around. | |
5966 Try also when reload_in is a pseudo without a hard reg. */ | |
5967 if (rld[r].in != 0 && rld[r].reg_rtx != 0 | |
5968 && (rtx_equal_p (rld[r].in, rld[r].reg_rtx) | |
5969 || (rtx_equal_p (rld[r].out, rld[r].reg_rtx) | |
5970 && !MEM_P (rld[r].in) | |
5971 && true_regnum (rld[r].in) < FIRST_PSEUDO_REGISTER))) | |
5972 continue; | |
5973 | |
5974 #if 0 /* No longer needed for correct operation. | |
5975 It might give better code, or might not; worth an experiment? */ | |
5976 /* If this is an optional reload, we can't inherit from earlier insns | |
5977 until we are sure that any non-optional reloads have been allocated. | |
5978 The following code takes advantage of the fact that optional reloads | |
5979 are at the end of reload_order. */ | |
5980 if (rld[r].optional != 0) | |
5981 for (i = 0; i < j; i++) | |
5982 if ((rld[reload_order[i]].out != 0 | |
5983 || rld[reload_order[i]].in != 0 | |
5984 || rld[reload_order[i]].secondary_p) | |
5985 && ! rld[reload_order[i]].optional | |
5986 && rld[reload_order[i]].reg_rtx == 0) | |
5987 allocate_reload_reg (chain, reload_order[i], 0); | |
5988 #endif | |
5989 | |
5990 /* First see if this pseudo is already available as reloaded | |
5991 for a previous insn. We cannot try to inherit for reloads | |
5992 that are smaller than the maximum number of registers needed | |
5993 for groups unless the register we would allocate cannot be used | |
5994 for the groups. | |
5995 | |
5996 We could check here to see if this is a secondary reload for | |
5997 an object that is already in a register of the desired class. | |
5998 This would avoid the need for the secondary reload register. | |
5999 But this is complex because we can't easily determine what | |
6000 objects might want to be loaded via this reload. So let a | |
6001 register be allocated here. In `emit_reload_insns' we suppress | |
6002 one of the loads in the case described above. */ | |
6003 | |
6004 if (inheritance) | |
6005 { | |
6006 int byte = 0; | |
6007 int regno = -1; | |
6008 enum machine_mode mode = VOIDmode; | |
6009 | |
6010 if (rld[r].in == 0) | |
6011 ; | |
6012 else if (REG_P (rld[r].in)) | |
6013 { | |
6014 regno = REGNO (rld[r].in); | |
6015 mode = GET_MODE (rld[r].in); | |
6016 } | |
6017 else if (REG_P (rld[r].in_reg)) | |
6018 { | |
6019 regno = REGNO (rld[r].in_reg); | |
6020 mode = GET_MODE (rld[r].in_reg); | |
6021 } | |
6022 else if (GET_CODE (rld[r].in_reg) == SUBREG | |
6023 && REG_P (SUBREG_REG (rld[r].in_reg))) | |
6024 { | |
6025 regno = REGNO (SUBREG_REG (rld[r].in_reg)); | |
6026 if (regno < FIRST_PSEUDO_REGISTER) | |
6027 regno = subreg_regno (rld[r].in_reg); | |
6028 else | |
6029 byte = SUBREG_BYTE (rld[r].in_reg); | |
6030 mode = GET_MODE (rld[r].in_reg); | |
6031 } | |
6032 #ifdef AUTO_INC_DEC | |
6033 else if (GET_RTX_CLASS (GET_CODE (rld[r].in_reg)) == RTX_AUTOINC | |
6034 && REG_P (XEXP (rld[r].in_reg, 0))) | |
6035 { | |
6036 regno = REGNO (XEXP (rld[r].in_reg, 0)); | |
6037 mode = GET_MODE (XEXP (rld[r].in_reg, 0)); | |
6038 rld[r].out = rld[r].in; | |
6039 } | |
6040 #endif | |
6041 #if 0 | |
6042 /* This won't work, since REGNO can be a pseudo reg number. | |
6043 Also, it takes much more hair to keep track of all the things | |
6044 that can invalidate an inherited reload of part of a pseudoreg. */ | |
6045 else if (GET_CODE (rld[r].in) == SUBREG | |
6046 && REG_P (SUBREG_REG (rld[r].in))) | |
6047 regno = subreg_regno (rld[r].in); | |
6048 #endif | |
6049 | |
6050 if (regno >= 0 | |
6051 && reg_last_reload_reg[regno] != 0 | |
6052 #ifdef CANNOT_CHANGE_MODE_CLASS | |
6053 /* Verify that the register it's in can be used in | |
6054 mode MODE. */ | |
6055 && !REG_CANNOT_CHANGE_MODE_P (REGNO (reg_last_reload_reg[regno]), | |
6056 GET_MODE (reg_last_reload_reg[regno]), | |
6057 mode) | |
6058 #endif | |
6059 ) | |
6060 { | |
6061 enum reg_class rclass = rld[r].rclass, last_class; | |
6062 rtx last_reg = reg_last_reload_reg[regno]; | |
6063 enum machine_mode need_mode; | |
6064 | |
6065 i = REGNO (last_reg); | |
6066 i += subreg_regno_offset (i, GET_MODE (last_reg), byte, mode); | |
6067 last_class = REGNO_REG_CLASS (i); | |
6068 | |
6069 if (byte == 0) | |
6070 need_mode = mode; | |
6071 else | |
6072 need_mode | |
6073 = smallest_mode_for_size | |
6074 (GET_MODE_BITSIZE (mode) + byte * BITS_PER_UNIT, | |
6075 GET_MODE_CLASS (mode) == MODE_PARTIAL_INT | |
6076 ? MODE_INT : GET_MODE_CLASS (mode)); | |
6077 | |
6078 if ((GET_MODE_SIZE (GET_MODE (last_reg)) | |
6079 >= GET_MODE_SIZE (need_mode)) | |
6080 && reg_reloaded_contents[i] == regno | |
6081 && TEST_HARD_REG_BIT (reg_reloaded_valid, i) | |
6082 && HARD_REGNO_MODE_OK (i, rld[r].mode) | |
6083 && (TEST_HARD_REG_BIT (reg_class_contents[(int) rclass], i) | |
6084 /* Even if we can't use this register as a reload | |
6085 register, we might use it for reload_override_in, | |
6086 if copying it to the desired class is cheap | |
6087 enough. */ | |
6088 || ((REGISTER_MOVE_COST (mode, last_class, rclass) | |
6089 < MEMORY_MOVE_COST (mode, rclass, 1)) | |
6090 && (secondary_reload_class (1, rclass, mode, | |
6091 last_reg) | |
6092 == NO_REGS) | |
6093 #ifdef SECONDARY_MEMORY_NEEDED | |
6094 && ! SECONDARY_MEMORY_NEEDED (last_class, rclass, | |
6095 mode) | |
6096 #endif | |
6097 )) | |
6098 | |
6099 && (rld[r].nregs == max_group_size | |
6100 || ! TEST_HARD_REG_BIT (reg_class_contents[(int) group_class], | |
6101 i)) | |
6102 && free_for_value_p (i, rld[r].mode, rld[r].opnum, | |
6103 rld[r].when_needed, rld[r].in, | |
6104 const0_rtx, r, 1)) | |
6105 { | |
6106 /* If a group is needed, verify that all the subsequent | |
6107 registers still have their values intact. */ | |
6108 int nr = hard_regno_nregs[i][rld[r].mode]; | |
6109 int k; | |
6110 | |
6111 for (k = 1; k < nr; k++) | |
6112 if (reg_reloaded_contents[i + k] != regno | |
6113 || ! TEST_HARD_REG_BIT (reg_reloaded_valid, i + k)) | |
6114 break; | |
6115 | |
6116 if (k == nr) | |
6117 { | |
6118 int i1; | |
6119 int bad_for_class; | |
6120 | |
6121 last_reg = (GET_MODE (last_reg) == mode | |
6122 ? last_reg : gen_rtx_REG (mode, i)); | |
6123 | |
6124 bad_for_class = 0; | |
6125 for (k = 0; k < nr; k++) | |
6126 bad_for_class |= ! TEST_HARD_REG_BIT (reg_class_contents[(int) rld[r].rclass], | |
6127 i+k); | |
6128 | |
6129 /* We found a register that contains the | |
6130 value we need. If this register is the | |
6131 same as an `earlyclobber' operand of the | |
6132 current insn, just mark it as a place to | |
6133 reload from since we can't use it as the | |
6134 reload register itself. */ | |
6135 | |
6136 for (i1 = 0; i1 < n_earlyclobbers; i1++) | |
6137 if (reg_overlap_mentioned_for_reload_p | |
6138 (reg_last_reload_reg[regno], | |
6139 reload_earlyclobbers[i1])) | |
6140 break; | |
6141 | |
6142 if (i1 != n_earlyclobbers | |
6143 || ! (free_for_value_p (i, rld[r].mode, | |
6144 rld[r].opnum, | |
6145 rld[r].when_needed, rld[r].in, | |
6146 rld[r].out, r, 1)) | |
6147 /* Don't use it if we'd clobber a pseudo reg. */ | |
6148 || (TEST_HARD_REG_BIT (reg_used_in_insn, i) | |
6149 && rld[r].out | |
6150 && ! TEST_HARD_REG_BIT (reg_reloaded_dead, i)) | |
6151 /* Don't clobber the frame pointer. */ | |
6152 || (i == HARD_FRAME_POINTER_REGNUM | |
6153 && frame_pointer_needed | |
6154 && rld[r].out) | |
6155 /* Don't really use the inherited spill reg | |
6156 if we need it wider than we've got it. */ | |
6157 || (GET_MODE_SIZE (rld[r].mode) | |
6158 > GET_MODE_SIZE (mode)) | |
6159 || bad_for_class | |
6160 | |
6161 /* If find_reloads chose reload_out as reload | |
6162 register, stay with it - that leaves the | |
6163 inherited register for subsequent reloads. */ | |
6164 || (rld[r].out && rld[r].reg_rtx | |
6165 && rtx_equal_p (rld[r].out, rld[r].reg_rtx))) | |
6166 { | |
6167 if (! rld[r].optional) | |
6168 { | |
6169 reload_override_in[r] = last_reg; | |
6170 reload_inheritance_insn[r] | |
6171 = reg_reloaded_insn[i]; | |
6172 } | |
6173 } | |
6174 else | |
6175 { | |
6176 int k; | |
6177 /* We can use this as a reload reg. */ | |
6178 /* Mark the register as in use for this part of | |
6179 the insn. */ | |
6180 mark_reload_reg_in_use (i, | |
6181 rld[r].opnum, | |
6182 rld[r].when_needed, | |
6183 rld[r].mode); | |
6184 rld[r].reg_rtx = last_reg; | |
6185 reload_inherited[r] = 1; | |
6186 reload_inheritance_insn[r] | |
6187 = reg_reloaded_insn[i]; | |
6188 reload_spill_index[r] = i; | |
6189 for (k = 0; k < nr; k++) | |
6190 SET_HARD_REG_BIT (reload_reg_used_for_inherit, | |
6191 i + k); | |
6192 } | |
6193 } | |
6194 } | |
6195 } | |
6196 } | |
6197 | |
6198 /* Here's another way to see if the value is already lying around. */ | |
6199 if (inheritance | |
6200 && rld[r].in != 0 | |
6201 && ! reload_inherited[r] | |
6202 && rld[r].out == 0 | |
6203 && (CONSTANT_P (rld[r].in) | |
6204 || GET_CODE (rld[r].in) == PLUS | |
6205 || REG_P (rld[r].in) | |
6206 || MEM_P (rld[r].in)) | |
6207 && (rld[r].nregs == max_group_size | |
6208 || ! reg_classes_intersect_p (rld[r].rclass, group_class))) | |
6209 search_equiv = rld[r].in; | |
6210 /* If this is an output reload from a simple move insn, look | |
6211 if an equivalence for the input is available. */ | |
6212 else if (inheritance && rld[r].in == 0 && rld[r].out != 0) | |
6213 { | |
6214 rtx set = single_set (insn); | |
6215 | |
6216 if (set | |
6217 && rtx_equal_p (rld[r].out, SET_DEST (set)) | |
6218 && CONSTANT_P (SET_SRC (set))) | |
6219 search_equiv = SET_SRC (set); | |
6220 } | |
6221 | |
6222 if (search_equiv) | |
6223 { | |
6224 rtx equiv | |
6225 = find_equiv_reg (search_equiv, insn, rld[r].rclass, | |
6226 -1, NULL, 0, rld[r].mode); | |
6227 int regno = 0; | |
6228 | |
6229 if (equiv != 0) | |
6230 { | |
6231 if (REG_P (equiv)) | |
6232 regno = REGNO (equiv); | |
6233 else | |
6234 { | |
6235 /* This must be a SUBREG of a hard register. | |
6236 Make a new REG since this might be used in an | |
6237 address and not all machines support SUBREGs | |
6238 there. */ | |
6239 gcc_assert (GET_CODE (equiv) == SUBREG); | |
6240 regno = subreg_regno (equiv); | |
6241 equiv = gen_rtx_REG (rld[r].mode, regno); | |
6242 /* If we choose EQUIV as the reload register, but the | |
6243 loop below decides to cancel the inheritance, we'll | |
6244 end up reloading EQUIV in rld[r].mode, not the mode | |
6245 it had originally. That isn't safe when EQUIV isn't | |
6246 available as a spill register since its value might | |
6247 still be live at this point. */ | |
6248 for (i = regno; i < regno + (int) rld[r].nregs; i++) | |
6249 if (TEST_HARD_REG_BIT (reload_reg_unavailable, i)) | |
6250 equiv = 0; | |
6251 } | |
6252 } | |
6253 | |
6254 /* If we found a spill reg, reject it unless it is free | |
6255 and of the desired class. */ | |
6256 if (equiv != 0) | |
6257 { | |
6258 int regs_used = 0; | |
6259 int bad_for_class = 0; | |
6260 int max_regno = regno + rld[r].nregs; | |
6261 | |
6262 for (i = regno; i < max_regno; i++) | |
6263 { | |
6264 regs_used |= TEST_HARD_REG_BIT (reload_reg_used_at_all, | |
6265 i); | |
6266 bad_for_class |= ! TEST_HARD_REG_BIT (reg_class_contents[(int) rld[r].rclass], | |
6267 i); | |
6268 } | |
6269 | |
6270 if ((regs_used | |
6271 && ! free_for_value_p (regno, rld[r].mode, | |
6272 rld[r].opnum, rld[r].when_needed, | |
6273 rld[r].in, rld[r].out, r, 1)) | |
6274 || bad_for_class) | |
6275 equiv = 0; | |
6276 } | |
6277 | |
6278 if (equiv != 0 && ! HARD_REGNO_MODE_OK (regno, rld[r].mode)) | |
6279 equiv = 0; | |
6280 | |
6281 /* We found a register that contains the value we need. | |
6282 If this register is the same as an `earlyclobber' operand | |
6283 of the current insn, just mark it as a place to reload from | |
6284 since we can't use it as the reload register itself. */ | |
6285 | |
6286 if (equiv != 0) | |
6287 for (i = 0; i < n_earlyclobbers; i++) | |
6288 if (reg_overlap_mentioned_for_reload_p (equiv, | |
6289 reload_earlyclobbers[i])) | |
6290 { | |
6291 if (! rld[r].optional) | |
6292 reload_override_in[r] = equiv; | |
6293 equiv = 0; | |
6294 break; | |
6295 } | |
6296 | |
6297 /* If the equiv register we have found is explicitly clobbered | |
6298 in the current insn, it depends on the reload type if we | |
6299 can use it, use it for reload_override_in, or not at all. | |
6300 In particular, we then can't use EQUIV for a | |
6301 RELOAD_FOR_OUTPUT_ADDRESS reload. */ | |
6302 | |
6303 if (equiv != 0) | |
6304 { | |
6305 if (regno_clobbered_p (regno, insn, rld[r].mode, 2)) | |
6306 switch (rld[r].when_needed) | |
6307 { | |
6308 case RELOAD_FOR_OTHER_ADDRESS: | |
6309 case RELOAD_FOR_INPADDR_ADDRESS: | |
6310 case RELOAD_FOR_INPUT_ADDRESS: | |
6311 case RELOAD_FOR_OPADDR_ADDR: | |
6312 break; | |
6313 case RELOAD_OTHER: | |
6314 case RELOAD_FOR_INPUT: | |
6315 case RELOAD_FOR_OPERAND_ADDRESS: | |
6316 if (! rld[r].optional) | |
6317 reload_override_in[r] = equiv; | |
6318 /* Fall through. */ | |
6319 default: | |
6320 equiv = 0; | |
6321 break; | |
6322 } | |
6323 else if (regno_clobbered_p (regno, insn, rld[r].mode, 1)) | |
6324 switch (rld[r].when_needed) | |
6325 { | |
6326 case RELOAD_FOR_OTHER_ADDRESS: | |
6327 case RELOAD_FOR_INPADDR_ADDRESS: | |
6328 case RELOAD_FOR_INPUT_ADDRESS: | |
6329 case RELOAD_FOR_OPADDR_ADDR: | |
6330 case RELOAD_FOR_OPERAND_ADDRESS: | |
6331 case RELOAD_FOR_INPUT: | |
6332 break; | |
6333 case RELOAD_OTHER: | |
6334 if (! rld[r].optional) | |
6335 reload_override_in[r] = equiv; | |
6336 /* Fall through. */ | |
6337 default: | |
6338 equiv = 0; | |
6339 break; | |
6340 } | |
6341 } | |
6342 | |
6343 /* If we found an equivalent reg, say no code need be generated | |
6344 to load it, and use it as our reload reg. */ | |
6345 if (equiv != 0 | |
6346 && (regno != HARD_FRAME_POINTER_REGNUM | |
6347 || !frame_pointer_needed)) | |
6348 { | |
6349 int nr = hard_regno_nregs[regno][rld[r].mode]; | |
6350 int k; | |
6351 rld[r].reg_rtx = equiv; | |
6352 reload_spill_index[r] = regno; | |
6353 reload_inherited[r] = 1; | |
6354 | |
6355 /* If reg_reloaded_valid is not set for this register, | |
6356 there might be a stale spill_reg_store lying around. | |
6357 We must clear it, since otherwise emit_reload_insns | |
6358 might delete the store. */ | |
6359 if (! TEST_HARD_REG_BIT (reg_reloaded_valid, regno)) | |
6360 spill_reg_store[regno] = NULL_RTX; | |
6361 /* If any of the hard registers in EQUIV are spill | |
6362 registers, mark them as in use for this insn. */ | |
6363 for (k = 0; k < nr; k++) | |
6364 { | |
6365 i = spill_reg_order[regno + k]; | |
6366 if (i >= 0) | |
6367 { | |
6368 mark_reload_reg_in_use (regno, rld[r].opnum, | |
6369 rld[r].when_needed, | |
6370 rld[r].mode); | |
6371 SET_HARD_REG_BIT (reload_reg_used_for_inherit, | |
6372 regno + k); | |
6373 } | |
6374 } | |
6375 } | |
6376 } | |
6377 | |
6378 /* If we found a register to use already, or if this is an optional | |
6379 reload, we are done. */ | |
6380 if (rld[r].reg_rtx != 0 || rld[r].optional != 0) | |
6381 continue; | |
6382 | |
6383 #if 0 | |
6384 /* No longer needed for correct operation. Might or might | |
6385 not give better code on the average. Want to experiment? */ | |
6386 | |
6387 /* See if there is a later reload that has a class different from our | |
6388 class that intersects our class or that requires less register | |
6389 than our reload. If so, we must allocate a register to this | |
6390 reload now, since that reload might inherit a previous reload | |
6391 and take the only available register in our class. Don't do this | |
6392 for optional reloads since they will force all previous reloads | |
6393 to be allocated. Also don't do this for reloads that have been | |
6394 turned off. */ | |
6395 | |
6396 for (i = j + 1; i < n_reloads; i++) | |
6397 { | |
6398 int s = reload_order[i]; | |
6399 | |
6400 if ((rld[s].in == 0 && rld[s].out == 0 | |
6401 && ! rld[s].secondary_p) | |
6402 || rld[s].optional) | |
6403 continue; | |
6404 | |
6405 if ((rld[s].rclass != rld[r].rclass | |
6406 && reg_classes_intersect_p (rld[r].rclass, | |
6407 rld[s].rclass)) | |
6408 || rld[s].nregs < rld[r].nregs) | |
6409 break; | |
6410 } | |
6411 | |
6412 if (i == n_reloads) | |
6413 continue; | |
6414 | |
6415 allocate_reload_reg (chain, r, j == n_reloads - 1); | |
6416 #endif | |
6417 } | |
6418 | |
6419 /* Now allocate reload registers for anything non-optional that | |
6420 didn't get one yet. */ | |
6421 for (j = 0; j < n_reloads; j++) | |
6422 { | |
6423 int r = reload_order[j]; | |
6424 | |
6425 /* Ignore reloads that got marked inoperative. */ | |
6426 if (rld[r].out == 0 && rld[r].in == 0 && ! rld[r].secondary_p) | |
6427 continue; | |
6428 | |
6429 /* Skip reloads that already have a register allocated or are | |
6430 optional. */ | |
6431 if (rld[r].reg_rtx != 0 || rld[r].optional) | |
6432 continue; | |
6433 | |
6434 if (! allocate_reload_reg (chain, r, j == n_reloads - 1)) | |
6435 break; | |
6436 } | |
6437 | |
6438 /* If that loop got all the way, we have won. */ | |
6439 if (j == n_reloads) | |
6440 { | |
6441 win = 1; | |
6442 break; | |
6443 } | |
6444 | |
6445 /* Loop around and try without any inheritance. */ | |
6446 } | |
6447 | |
6448 if (! win) | |
6449 { | |
6450 /* First undo everything done by the failed attempt | |
6451 to allocate with inheritance. */ | |
6452 choose_reload_regs_init (chain, save_reload_reg_rtx); | |
6453 | |
6454 /* Some sanity tests to verify that the reloads found in the first | |
6455 pass are identical to the ones we have now. */ | |
6456 gcc_assert (chain->n_reloads == n_reloads); | |
6457 | |
6458 for (i = 0; i < n_reloads; i++) | |
6459 { | |
6460 if (chain->rld[i].regno < 0 || chain->rld[i].reg_rtx != 0) | |
6461 continue; | |
6462 gcc_assert (chain->rld[i].when_needed == rld[i].when_needed); | |
6463 for (j = 0; j < n_spills; j++) | |
6464 if (spill_regs[j] == chain->rld[i].regno) | |
6465 if (! set_reload_reg (j, i)) | |
6466 failed_reload (chain->insn, i); | |
6467 } | |
6468 } | |
6469 | |
6470 /* If we thought we could inherit a reload, because it seemed that | |
6471 nothing else wanted the same reload register earlier in the insn, | |
6472 verify that assumption, now that all reloads have been assigned. | |
6473 Likewise for reloads where reload_override_in has been set. */ | |
6474 | |
6475 /* If doing expensive optimizations, do one preliminary pass that doesn't | |
6476 cancel any inheritance, but removes reloads that have been needed only | |
6477 for reloads that we know can be inherited. */ | |
6478 for (pass = flag_expensive_optimizations; pass >= 0; pass--) | |
6479 { | |
6480 for (j = 0; j < n_reloads; j++) | |
6481 { | |
6482 int r = reload_order[j]; | |
6483 rtx check_reg; | |
6484 if (reload_inherited[r] && rld[r].reg_rtx) | |
6485 check_reg = rld[r].reg_rtx; | |
6486 else if (reload_override_in[r] | |
6487 && (REG_P (reload_override_in[r]) | |
6488 || GET_CODE (reload_override_in[r]) == SUBREG)) | |
6489 check_reg = reload_override_in[r]; | |
6490 else | |
6491 continue; | |
6492 if (! free_for_value_p (true_regnum (check_reg), rld[r].mode, | |
6493 rld[r].opnum, rld[r].when_needed, rld[r].in, | |
6494 (reload_inherited[r] | |
6495 ? rld[r].out : const0_rtx), | |
6496 r, 1)) | |
6497 { | |
6498 if (pass) | |
6499 continue; | |
6500 reload_inherited[r] = 0; | |
6501 reload_override_in[r] = 0; | |
6502 } | |
6503 /* If we can inherit a RELOAD_FOR_INPUT, or can use a | |
6504 reload_override_in, then we do not need its related | |
6505 RELOAD_FOR_INPUT_ADDRESS / RELOAD_FOR_INPADDR_ADDRESS reloads; | |
6506 likewise for other reload types. | |
6507 We handle this by removing a reload when its only replacement | |
6508 is mentioned in reload_in of the reload we are going to inherit. | |
6509 A special case are auto_inc expressions; even if the input is | |
6510 inherited, we still need the address for the output. We can | |
6511 recognize them because they have RELOAD_OUT set to RELOAD_IN. | |
6512 If we succeeded removing some reload and we are doing a preliminary | |
6513 pass just to remove such reloads, make another pass, since the | |
6514 removal of one reload might allow us to inherit another one. */ | |
6515 else if (rld[r].in | |
6516 && rld[r].out != rld[r].in | |
6517 && remove_address_replacements (rld[r].in) && pass) | |
6518 pass = 2; | |
6519 } | |
6520 } | |
6521 | |
6522 /* Now that reload_override_in is known valid, | |
6523 actually override reload_in. */ | |
6524 for (j = 0; j < n_reloads; j++) | |
6525 if (reload_override_in[j]) | |
6526 rld[j].in = reload_override_in[j]; | |
6527 | |
6528 /* If this reload won't be done because it has been canceled or is | |
6529 optional and not inherited, clear reload_reg_rtx so other | |
6530 routines (such as subst_reloads) don't get confused. */ | |
6531 for (j = 0; j < n_reloads; j++) | |
6532 if (rld[j].reg_rtx != 0 | |
6533 && ((rld[j].optional && ! reload_inherited[j]) | |
6534 || (rld[j].in == 0 && rld[j].out == 0 | |
6535 && ! rld[j].secondary_p))) | |
6536 { | |
6537 int regno = true_regnum (rld[j].reg_rtx); | |
6538 | |
6539 if (spill_reg_order[regno] >= 0) | |
6540 clear_reload_reg_in_use (regno, rld[j].opnum, | |
6541 rld[j].when_needed, rld[j].mode); | |
6542 rld[j].reg_rtx = 0; | |
6543 reload_spill_index[j] = -1; | |
6544 } | |
6545 | |
6546 /* Record which pseudos and which spill regs have output reloads. */ | |
6547 for (j = 0; j < n_reloads; j++) | |
6548 { | |
6549 int r = reload_order[j]; | |
6550 | |
6551 i = reload_spill_index[r]; | |
6552 | |
6553 /* I is nonneg if this reload uses a register. | |
6554 If rld[r].reg_rtx is 0, this is an optional reload | |
6555 that we opted to ignore. */ | |
6556 if (rld[r].out_reg != 0 && REG_P (rld[r].out_reg) | |
6557 && rld[r].reg_rtx != 0) | |
6558 { | |
6559 int nregno = REGNO (rld[r].out_reg); | |
6560 int nr = 1; | |
6561 | |
6562 if (nregno < FIRST_PSEUDO_REGISTER) | |
6563 nr = hard_regno_nregs[nregno][rld[r].mode]; | |
6564 | |
6565 while (--nr >= 0) | |
6566 SET_REGNO_REG_SET (®_has_output_reload, | |
6567 nregno + nr); | |
6568 | |
6569 if (i >= 0) | |
6570 { | |
6571 nr = hard_regno_nregs[i][rld[r].mode]; | |
6572 while (--nr >= 0) | |
6573 SET_HARD_REG_BIT (reg_is_output_reload, i + nr); | |
6574 } | |
6575 | |
6576 gcc_assert (rld[r].when_needed == RELOAD_OTHER | |
6577 || rld[r].when_needed == RELOAD_FOR_OUTPUT | |
6578 || rld[r].when_needed == RELOAD_FOR_INSN); | |
6579 } | |
6580 } | |
6581 } | |
6582 | |
6583 /* Deallocate the reload register for reload R. This is called from | |
6584 remove_address_replacements. */ | |
6585 | |
6586 void | |
6587 deallocate_reload_reg (int r) | |
6588 { | |
6589 int regno; | |
6590 | |
6591 if (! rld[r].reg_rtx) | |
6592 return; | |
6593 regno = true_regnum (rld[r].reg_rtx); | |
6594 rld[r].reg_rtx = 0; | |
6595 if (spill_reg_order[regno] >= 0) | |
6596 clear_reload_reg_in_use (regno, rld[r].opnum, rld[r].when_needed, | |
6597 rld[r].mode); | |
6598 reload_spill_index[r] = -1; | |
6599 } | |
6600 | |
6601 /* If SMALL_REGISTER_CLASSES is nonzero, we may not have merged two | |
6602 reloads of the same item for fear that we might not have enough reload | |
6603 registers. However, normally they will get the same reload register | |
6604 and hence actually need not be loaded twice. | |
6605 | |
6606 Here we check for the most common case of this phenomenon: when we have | |
6607 a number of reloads for the same object, each of which were allocated | |
6608 the same reload_reg_rtx, that reload_reg_rtx is not used for any other | |
6609 reload, and is not modified in the insn itself. If we find such, | |
6610 merge all the reloads and set the resulting reload to RELOAD_OTHER. | |
6611 This will not increase the number of spill registers needed and will | |
6612 prevent redundant code. */ | |
6613 | |
6614 static void | |
6615 merge_assigned_reloads (rtx insn) | |
6616 { | |
6617 int i, j; | |
6618 | |
6619 /* Scan all the reloads looking for ones that only load values and | |
6620 are not already RELOAD_OTHER and ones whose reload_reg_rtx are | |
6621 assigned and not modified by INSN. */ | |
6622 | |
6623 for (i = 0; i < n_reloads; i++) | |
6624 { | |
6625 int conflicting_input = 0; | |
6626 int max_input_address_opnum = -1; | |
6627 int min_conflicting_input_opnum = MAX_RECOG_OPERANDS; | |
6628 | |
6629 if (rld[i].in == 0 || rld[i].when_needed == RELOAD_OTHER | |
6630 || rld[i].out != 0 || rld[i].reg_rtx == 0 | |
6631 || reg_set_p (rld[i].reg_rtx, insn)) | |
6632 continue; | |
6633 | |
6634 /* Look at all other reloads. Ensure that the only use of this | |
6635 reload_reg_rtx is in a reload that just loads the same value | |
6636 as we do. Note that any secondary reloads must be of the identical | |
6637 class since the values, modes, and result registers are the | |
6638 same, so we need not do anything with any secondary reloads. */ | |
6639 | |
6640 for (j = 0; j < n_reloads; j++) | |
6641 { | |
6642 if (i == j || rld[j].reg_rtx == 0 | |
6643 || ! reg_overlap_mentioned_p (rld[j].reg_rtx, | |
6644 rld[i].reg_rtx)) | |
6645 continue; | |
6646 | |
6647 if (rld[j].when_needed == RELOAD_FOR_INPUT_ADDRESS | |
6648 && rld[j].opnum > max_input_address_opnum) | |
6649 max_input_address_opnum = rld[j].opnum; | |
6650 | |
6651 /* If the reload regs aren't exactly the same (e.g, different modes) | |
6652 or if the values are different, we can't merge this reload. | |
6653 But if it is an input reload, we might still merge | |
6654 RELOAD_FOR_INPUT_ADDRESS and RELOAD_FOR_OTHER_ADDRESS reloads. */ | |
6655 | |
6656 if (! rtx_equal_p (rld[i].reg_rtx, rld[j].reg_rtx) | |
6657 || rld[j].out != 0 || rld[j].in == 0 | |
6658 || ! rtx_equal_p (rld[i].in, rld[j].in)) | |
6659 { | |
6660 if (rld[j].when_needed != RELOAD_FOR_INPUT | |
6661 || ((rld[i].when_needed != RELOAD_FOR_INPUT_ADDRESS | |
6662 || rld[i].opnum > rld[j].opnum) | |
6663 && rld[i].when_needed != RELOAD_FOR_OTHER_ADDRESS)) | |
6664 break; | |
6665 conflicting_input = 1; | |
6666 if (min_conflicting_input_opnum > rld[j].opnum) | |
6667 min_conflicting_input_opnum = rld[j].opnum; | |
6668 } | |
6669 } | |
6670 | |
6671 /* If all is OK, merge the reloads. Only set this to RELOAD_OTHER if | |
6672 we, in fact, found any matching reloads. */ | |
6673 | |
6674 if (j == n_reloads | |
6675 && max_input_address_opnum <= min_conflicting_input_opnum) | |
6676 { | |
6677 gcc_assert (rld[i].when_needed != RELOAD_FOR_OUTPUT); | |
6678 | |
6679 for (j = 0; j < n_reloads; j++) | |
6680 if (i != j && rld[j].reg_rtx != 0 | |
6681 && rtx_equal_p (rld[i].reg_rtx, rld[j].reg_rtx) | |
6682 && (! conflicting_input | |
6683 || rld[j].when_needed == RELOAD_FOR_INPUT_ADDRESS | |
6684 || rld[j].when_needed == RELOAD_FOR_OTHER_ADDRESS)) | |
6685 { | |
6686 rld[i].when_needed = RELOAD_OTHER; | |
6687 rld[j].in = 0; | |
6688 reload_spill_index[j] = -1; | |
6689 transfer_replacements (i, j); | |
6690 } | |
6691 | |
6692 /* If this is now RELOAD_OTHER, look for any reloads that | |
6693 load parts of this operand and set them to | |
6694 RELOAD_FOR_OTHER_ADDRESS if they were for inputs, | |
6695 RELOAD_OTHER for outputs. Note that this test is | |
6696 equivalent to looking for reloads for this operand | |
6697 number. | |
6698 | |
6699 We must take special care with RELOAD_FOR_OUTPUT_ADDRESS; | |
6700 it may share registers with a RELOAD_FOR_INPUT, so we can | |
6701 not change it to RELOAD_FOR_OTHER_ADDRESS. We should | |
6702 never need to, since we do not modify RELOAD_FOR_OUTPUT. | |
6703 | |
6704 It is possible that the RELOAD_FOR_OPERAND_ADDRESS | |
6705 instruction is assigned the same register as the earlier | |
6706 RELOAD_FOR_OTHER_ADDRESS instruction. Merging these two | |
6707 instructions will cause the RELOAD_FOR_OTHER_ADDRESS | |
6708 instruction to be deleted later on. */ | |
6709 | |
6710 if (rld[i].when_needed == RELOAD_OTHER) | |
6711 for (j = 0; j < n_reloads; j++) | |
6712 if (rld[j].in != 0 | |
6713 && rld[j].when_needed != RELOAD_OTHER | |
6714 && rld[j].when_needed != RELOAD_FOR_OTHER_ADDRESS | |
6715 && rld[j].when_needed != RELOAD_FOR_OUTPUT_ADDRESS | |
6716 && rld[j].when_needed != RELOAD_FOR_OPERAND_ADDRESS | |
6717 && (! conflicting_input | |
6718 || rld[j].when_needed == RELOAD_FOR_INPUT_ADDRESS | |
6719 || rld[j].when_needed == RELOAD_FOR_INPADDR_ADDRESS) | |
6720 && reg_overlap_mentioned_for_reload_p (rld[j].in, | |
6721 rld[i].in)) | |
6722 { | |
6723 int k; | |
6724 | |
6725 rld[j].when_needed | |
6726 = ((rld[j].when_needed == RELOAD_FOR_INPUT_ADDRESS | |
6727 || rld[j].when_needed == RELOAD_FOR_INPADDR_ADDRESS) | |
6728 ? RELOAD_FOR_OTHER_ADDRESS : RELOAD_OTHER); | |
6729 | |
6730 /* Check to see if we accidentally converted two | |
6731 reloads that use the same reload register with | |
6732 different inputs to the same type. If so, the | |
6733 resulting code won't work. */ | |
6734 if (rld[j].reg_rtx) | |
6735 for (k = 0; k < j; k++) | |
6736 gcc_assert (rld[k].in == 0 || rld[k].reg_rtx == 0 | |
6737 || rld[k].when_needed != rld[j].when_needed | |
6738 || !rtx_equal_p (rld[k].reg_rtx, | |
6739 rld[j].reg_rtx) | |
6740 || rtx_equal_p (rld[k].in, | |
6741 rld[j].in)); | |
6742 } | |
6743 } | |
6744 } | |
6745 } | |
6746 | |
6747 /* These arrays are filled by emit_reload_insns and its subroutines. */ | |
6748 static rtx input_reload_insns[MAX_RECOG_OPERANDS]; | |
6749 static rtx other_input_address_reload_insns = 0; | |
6750 static rtx other_input_reload_insns = 0; | |
6751 static rtx input_address_reload_insns[MAX_RECOG_OPERANDS]; | |
6752 static rtx inpaddr_address_reload_insns[MAX_RECOG_OPERANDS]; | |
6753 static rtx output_reload_insns[MAX_RECOG_OPERANDS]; | |
6754 static rtx output_address_reload_insns[MAX_RECOG_OPERANDS]; | |
6755 static rtx outaddr_address_reload_insns[MAX_RECOG_OPERANDS]; | |
6756 static rtx operand_reload_insns = 0; | |
6757 static rtx other_operand_reload_insns = 0; | |
6758 static rtx other_output_reload_insns[MAX_RECOG_OPERANDS]; | |
6759 | |
6760 /* Values to be put in spill_reg_store are put here first. */ | |
6761 static rtx new_spill_reg_store[FIRST_PSEUDO_REGISTER]; | |
6762 static HARD_REG_SET reg_reloaded_died; | |
6763 | |
6764 /* Check if *RELOAD_REG is suitable as an intermediate or scratch register | |
6765 of class NEW_CLASS with mode NEW_MODE. Or alternatively, if alt_reload_reg | |
6766 is nonzero, if that is suitable. On success, change *RELOAD_REG to the | |
6767 adjusted register, and return true. Otherwise, return false. */ | |
6768 static bool | |
6769 reload_adjust_reg_for_temp (rtx *reload_reg, rtx alt_reload_reg, | |
6770 enum reg_class new_class, | |
6771 enum machine_mode new_mode) | |
6772 | |
6773 { | |
6774 rtx reg; | |
6775 | |
6776 for (reg = *reload_reg; reg; reg = alt_reload_reg, alt_reload_reg = 0) | |
6777 { | |
6778 unsigned regno = REGNO (reg); | |
6779 | |
6780 if (!TEST_HARD_REG_BIT (reg_class_contents[(int) new_class], regno)) | |
6781 continue; | |
6782 if (GET_MODE (reg) != new_mode) | |
6783 { | |
6784 if (!HARD_REGNO_MODE_OK (regno, new_mode)) | |
6785 continue; | |
6786 if (hard_regno_nregs[regno][new_mode] | |
6787 > hard_regno_nregs[regno][GET_MODE (reg)]) | |
6788 continue; | |
6789 reg = reload_adjust_reg_for_mode (reg, new_mode); | |
6790 } | |
6791 *reload_reg = reg; | |
6792 return true; | |
6793 } | |
6794 return false; | |
6795 } | |
6796 | |
6797 /* Check if *RELOAD_REG is suitable as a scratch register for the reload | |
6798 pattern with insn_code ICODE, or alternatively, if alt_reload_reg is | |
6799 nonzero, if that is suitable. On success, change *RELOAD_REG to the | |
6800 adjusted register, and return true. Otherwise, return false. */ | |
6801 static bool | |
6802 reload_adjust_reg_for_icode (rtx *reload_reg, rtx alt_reload_reg, | |
6803 enum insn_code icode) | |
6804 | |
6805 { | |
6806 enum reg_class new_class = scratch_reload_class (icode); | |
6807 enum machine_mode new_mode = insn_data[(int) icode].operand[2].mode; | |
6808 | |
6809 return reload_adjust_reg_for_temp (reload_reg, alt_reload_reg, | |
6810 new_class, new_mode); | |
6811 } | |
6812 | |
6813 /* Generate insns to perform reload RL, which is for the insn in CHAIN and | |
6814 has the number J. OLD contains the value to be used as input. */ | |
6815 | |
6816 static void | |
6817 emit_input_reload_insns (struct insn_chain *chain, struct reload *rl, | |
6818 rtx old, int j) | |
6819 { | |
6820 rtx insn = chain->insn; | |
6821 rtx reloadreg; | |
6822 rtx oldequiv_reg = 0; | |
6823 rtx oldequiv = 0; | |
6824 int special = 0; | |
6825 enum machine_mode mode; | |
6826 rtx *where; | |
6827 | |
6828 /* delete_output_reload is only invoked properly if old contains | |
6829 the original pseudo register. Since this is replaced with a | |
6830 hard reg when RELOAD_OVERRIDE_IN is set, see if we can | |
6831 find the pseudo in RELOAD_IN_REG. */ | |
6832 if (reload_override_in[j] | |
6833 && REG_P (rl->in_reg)) | |
6834 { | |
6835 oldequiv = old; | |
6836 old = rl->in_reg; | |
6837 } | |
6838 if (oldequiv == 0) | |
6839 oldequiv = old; | |
6840 else if (REG_P (oldequiv)) | |
6841 oldequiv_reg = oldequiv; | |
6842 else if (GET_CODE (oldequiv) == SUBREG) | |
6843 oldequiv_reg = SUBREG_REG (oldequiv); | |
6844 | |
6845 reloadreg = reload_reg_rtx_for_input[j]; | |
6846 mode = GET_MODE (reloadreg); | |
6847 | |
6848 /* If we are reloading from a register that was recently stored in | |
6849 with an output-reload, see if we can prove there was | |
6850 actually no need to store the old value in it. */ | |
6851 | |
6852 if (optimize && REG_P (oldequiv) | |
6853 && REGNO (oldequiv) < FIRST_PSEUDO_REGISTER | |
6854 && spill_reg_store[REGNO (oldequiv)] | |
6855 && REG_P (old) | |
6856 && (dead_or_set_p (insn, spill_reg_stored_to[REGNO (oldequiv)]) | |
6857 || rtx_equal_p (spill_reg_stored_to[REGNO (oldequiv)], | |
6858 rl->out_reg))) | |
6859 delete_output_reload (insn, j, REGNO (oldequiv), reloadreg); | |
6860 | |
6861 /* Encapsulate OLDEQUIV into the reload mode, then load RELOADREG from | |
6862 OLDEQUIV. */ | |
6863 | |
6864 while (GET_CODE (oldequiv) == SUBREG && GET_MODE (oldequiv) != mode) | |
6865 oldequiv = SUBREG_REG (oldequiv); | |
6866 if (GET_MODE (oldequiv) != VOIDmode | |
6867 && mode != GET_MODE (oldequiv)) | |
6868 oldequiv = gen_lowpart_SUBREG (mode, oldequiv); | |
6869 | |
6870 /* Switch to the right place to emit the reload insns. */ | |
6871 switch (rl->when_needed) | |
6872 { | |
6873 case RELOAD_OTHER: | |
6874 where = &other_input_reload_insns; | |
6875 break; | |
6876 case RELOAD_FOR_INPUT: | |
6877 where = &input_reload_insns[rl->opnum]; | |
6878 break; | |
6879 case RELOAD_FOR_INPUT_ADDRESS: | |
6880 where = &input_address_reload_insns[rl->opnum]; | |
6881 break; | |
6882 case RELOAD_FOR_INPADDR_ADDRESS: | |
6883 where = &inpaddr_address_reload_insns[rl->opnum]; | |
6884 break; | |
6885 case RELOAD_FOR_OUTPUT_ADDRESS: | |
6886 where = &output_address_reload_insns[rl->opnum]; | |
6887 break; | |
6888 case RELOAD_FOR_OUTADDR_ADDRESS: | |
6889 where = &outaddr_address_reload_insns[rl->opnum]; | |
6890 break; | |
6891 case RELOAD_FOR_OPERAND_ADDRESS: | |
6892 where = &operand_reload_insns; | |
6893 break; | |
6894 case RELOAD_FOR_OPADDR_ADDR: | |
6895 where = &other_operand_reload_insns; | |
6896 break; | |
6897 case RELOAD_FOR_OTHER_ADDRESS: | |
6898 where = &other_input_address_reload_insns; | |
6899 break; | |
6900 default: | |
6901 gcc_unreachable (); | |
6902 } | |
6903 | |
6904 push_to_sequence (*where); | |
6905 | |
6906 /* Auto-increment addresses must be reloaded in a special way. */ | |
6907 if (rl->out && ! rl->out_reg) | |
6908 { | |
6909 /* We are not going to bother supporting the case where a | |
6910 incremented register can't be copied directly from | |
6911 OLDEQUIV since this seems highly unlikely. */ | |
6912 gcc_assert (rl->secondary_in_reload < 0); | |
6913 | |
6914 if (reload_inherited[j]) | |
6915 oldequiv = reloadreg; | |
6916 | |
6917 old = XEXP (rl->in_reg, 0); | |
6918 | |
6919 if (optimize && REG_P (oldequiv) | |
6920 && REGNO (oldequiv) < FIRST_PSEUDO_REGISTER | |
6921 && spill_reg_store[REGNO (oldequiv)] | |
6922 && REG_P (old) | |
6923 && (dead_or_set_p (insn, | |
6924 spill_reg_stored_to[REGNO (oldequiv)]) | |
6925 || rtx_equal_p (spill_reg_stored_to[REGNO (oldequiv)], | |
6926 old))) | |
6927 delete_output_reload (insn, j, REGNO (oldequiv), reloadreg); | |
6928 | |
6929 /* Prevent normal processing of this reload. */ | |
6930 special = 1; | |
6931 /* Output a special code sequence for this case. */ | |
6932 new_spill_reg_store[REGNO (reloadreg)] | |
6933 = inc_for_reload (reloadreg, oldequiv, rl->out, | |
6934 rl->inc); | |
6935 } | |
6936 | |
6937 /* If we are reloading a pseudo-register that was set by the previous | |
6938 insn, see if we can get rid of that pseudo-register entirely | |
6939 by redirecting the previous insn into our reload register. */ | |
6940 | |
6941 else if (optimize && REG_P (old) | |
6942 && REGNO (old) >= FIRST_PSEUDO_REGISTER | |
6943 && dead_or_set_p (insn, old) | |
6944 /* This is unsafe if some other reload | |
6945 uses the same reg first. */ | |
6946 && ! conflicts_with_override (reloadreg) | |
6947 && free_for_value_p (REGNO (reloadreg), rl->mode, rl->opnum, | |
6948 rl->when_needed, old, rl->out, j, 0)) | |
6949 { | |
6950 rtx temp = PREV_INSN (insn); | |
6951 while (temp && NOTE_P (temp)) | |
6952 temp = PREV_INSN (temp); | |
6953 if (temp | |
6954 && NONJUMP_INSN_P (temp) | |
6955 && GET_CODE (PATTERN (temp)) == SET | |
6956 && SET_DEST (PATTERN (temp)) == old | |
6957 /* Make sure we can access insn_operand_constraint. */ | |
6958 && asm_noperands (PATTERN (temp)) < 0 | |
6959 /* This is unsafe if operand occurs more than once in current | |
6960 insn. Perhaps some occurrences aren't reloaded. */ | |
6961 && count_occurrences (PATTERN (insn), old, 0) == 1) | |
6962 { | |
6963 rtx old = SET_DEST (PATTERN (temp)); | |
6964 /* Store into the reload register instead of the pseudo. */ | |
6965 SET_DEST (PATTERN (temp)) = reloadreg; | |
6966 | |
6967 /* Verify that resulting insn is valid. */ | |
6968 extract_insn (temp); | |
6969 if (constrain_operands (1)) | |
6970 { | |
6971 /* If the previous insn is an output reload, the source is | |
6972 a reload register, and its spill_reg_store entry will | |
6973 contain the previous destination. This is now | |
6974 invalid. */ | |
6975 if (REG_P (SET_SRC (PATTERN (temp))) | |
6976 && REGNO (SET_SRC (PATTERN (temp))) < FIRST_PSEUDO_REGISTER) | |
6977 { | |
6978 spill_reg_store[REGNO (SET_SRC (PATTERN (temp)))] = 0; | |
6979 spill_reg_stored_to[REGNO (SET_SRC (PATTERN (temp)))] = 0; | |
6980 } | |
6981 | |
6982 /* If these are the only uses of the pseudo reg, | |
6983 pretend for GDB it lives in the reload reg we used. */ | |
6984 if (REG_N_DEATHS (REGNO (old)) == 1 | |
6985 && REG_N_SETS (REGNO (old)) == 1) | |
6986 { | |
6987 reg_renumber[REGNO (old)] = REGNO (reloadreg); | |
6988 if (ira_conflicts_p) | |
6989 /* Inform IRA about the change. */ | |
6990 ira_mark_allocation_change (REGNO (old)); | |
6991 alter_reg (REGNO (old), -1, false); | |
6992 } | |
6993 special = 1; | |
6994 } | |
6995 else | |
6996 { | |
6997 SET_DEST (PATTERN (temp)) = old; | |
6998 } | |
6999 } | |
7000 } | |
7001 | |
7002 /* We can't do that, so output an insn to load RELOADREG. */ | |
7003 | |
7004 /* If we have a secondary reload, pick up the secondary register | |
7005 and icode, if any. If OLDEQUIV and OLD are different or | |
7006 if this is an in-out reload, recompute whether or not we | |
7007 still need a secondary register and what the icode should | |
7008 be. If we still need a secondary register and the class or | |
7009 icode is different, go back to reloading from OLD if using | |
7010 OLDEQUIV means that we got the wrong type of register. We | |
7011 cannot have different class or icode due to an in-out reload | |
7012 because we don't make such reloads when both the input and | |
7013 output need secondary reload registers. */ | |
7014 | |
7015 if (! special && rl->secondary_in_reload >= 0) | |
7016 { | |
7017 rtx second_reload_reg = 0; | |
7018 rtx third_reload_reg = 0; | |
7019 int secondary_reload = rl->secondary_in_reload; | |
7020 rtx real_oldequiv = oldequiv; | |
7021 rtx real_old = old; | |
7022 rtx tmp; | |
7023 enum insn_code icode; | |
7024 enum insn_code tertiary_icode = CODE_FOR_nothing; | |
7025 | |
7026 /* If OLDEQUIV is a pseudo with a MEM, get the real MEM | |
7027 and similarly for OLD. | |
7028 See comments in get_secondary_reload in reload.c. */ | |
7029 /* If it is a pseudo that cannot be replaced with its | |
7030 equivalent MEM, we must fall back to reload_in, which | |
7031 will have all the necessary substitutions registered. | |
7032 Likewise for a pseudo that can't be replaced with its | |
7033 equivalent constant. | |
7034 | |
7035 Take extra care for subregs of such pseudos. Note that | |
7036 we cannot use reg_equiv_mem in this case because it is | |
7037 not in the right mode. */ | |
7038 | |
7039 tmp = oldequiv; | |
7040 if (GET_CODE (tmp) == SUBREG) | |
7041 tmp = SUBREG_REG (tmp); | |
7042 if (REG_P (tmp) | |
7043 && REGNO (tmp) >= FIRST_PSEUDO_REGISTER | |
7044 && (reg_equiv_memory_loc[REGNO (tmp)] != 0 | |
7045 || reg_equiv_constant[REGNO (tmp)] != 0)) | |
7046 { | |
7047 if (! reg_equiv_mem[REGNO (tmp)] | |
7048 || num_not_at_initial_offset | |
7049 || GET_CODE (oldequiv) == SUBREG) | |
7050 real_oldequiv = rl->in; | |
7051 else | |
7052 real_oldequiv = reg_equiv_mem[REGNO (tmp)]; | |
7053 } | |
7054 | |
7055 tmp = old; | |
7056 if (GET_CODE (tmp) == SUBREG) | |
7057 tmp = SUBREG_REG (tmp); | |
7058 if (REG_P (tmp) | |
7059 && REGNO (tmp) >= FIRST_PSEUDO_REGISTER | |
7060 && (reg_equiv_memory_loc[REGNO (tmp)] != 0 | |
7061 || reg_equiv_constant[REGNO (tmp)] != 0)) | |
7062 { | |
7063 if (! reg_equiv_mem[REGNO (tmp)] | |
7064 || num_not_at_initial_offset | |
7065 || GET_CODE (old) == SUBREG) | |
7066 real_old = rl->in; | |
7067 else | |
7068 real_old = reg_equiv_mem[REGNO (tmp)]; | |
7069 } | |
7070 | |
7071 second_reload_reg = rld[secondary_reload].reg_rtx; | |
7072 if (rld[secondary_reload].secondary_in_reload >= 0) | |
7073 { | |
7074 int tertiary_reload = rld[secondary_reload].secondary_in_reload; | |
7075 | |
7076 third_reload_reg = rld[tertiary_reload].reg_rtx; | |
7077 tertiary_icode = rld[secondary_reload].secondary_in_icode; | |
7078 /* We'd have to add more code for quartary reloads. */ | |
7079 gcc_assert (rld[tertiary_reload].secondary_in_reload < 0); | |
7080 } | |
7081 icode = rl->secondary_in_icode; | |
7082 | |
7083 if ((old != oldequiv && ! rtx_equal_p (old, oldequiv)) | |
7084 || (rl->in != 0 && rl->out != 0)) | |
7085 { | |
7086 secondary_reload_info sri, sri2; | |
7087 enum reg_class new_class, new_t_class; | |
7088 | |
7089 sri.icode = CODE_FOR_nothing; | |
7090 sri.prev_sri = NULL; | |
7091 new_class = targetm.secondary_reload (1, real_oldequiv, rl->rclass, | |
7092 mode, &sri); | |
7093 | |
7094 if (new_class == NO_REGS && sri.icode == CODE_FOR_nothing) | |
7095 second_reload_reg = 0; | |
7096 else if (new_class == NO_REGS) | |
7097 { | |
7098 if (reload_adjust_reg_for_icode (&second_reload_reg, | |
7099 third_reload_reg, sri.icode)) | |
7100 icode = sri.icode, third_reload_reg = 0; | |
7101 else | |
7102 oldequiv = old, real_oldequiv = real_old; | |
7103 } | |
7104 else if (sri.icode != CODE_FOR_nothing) | |
7105 /* We currently lack a way to express this in reloads. */ | |
7106 gcc_unreachable (); | |
7107 else | |
7108 { | |
7109 sri2.icode = CODE_FOR_nothing; | |
7110 sri2.prev_sri = &sri; | |
7111 new_t_class = targetm.secondary_reload (1, real_oldequiv, | |
7112 new_class, mode, &sri); | |
7113 if (new_t_class == NO_REGS && sri2.icode == CODE_FOR_nothing) | |
7114 { | |
7115 if (reload_adjust_reg_for_temp (&second_reload_reg, | |
7116 third_reload_reg, | |
7117 new_class, mode)) | |
7118 third_reload_reg = 0, tertiary_icode = sri2.icode; | |
7119 else | |
7120 oldequiv = old, real_oldequiv = real_old; | |
7121 } | |
7122 else if (new_t_class == NO_REGS && sri2.icode != CODE_FOR_nothing) | |
7123 { | |
7124 rtx intermediate = second_reload_reg; | |
7125 | |
7126 if (reload_adjust_reg_for_temp (&intermediate, NULL, | |
7127 new_class, mode) | |
7128 && reload_adjust_reg_for_icode (&third_reload_reg, NULL, | |
7129 sri2.icode)) | |
7130 { | |
7131 second_reload_reg = intermediate; | |
7132 tertiary_icode = sri2.icode; | |
7133 } | |
7134 else | |
7135 oldequiv = old, real_oldequiv = real_old; | |
7136 } | |
7137 else if (new_t_class != NO_REGS && sri2.icode == CODE_FOR_nothing) | |
7138 { | |
7139 rtx intermediate = second_reload_reg; | |
7140 | |
7141 if (reload_adjust_reg_for_temp (&intermediate, NULL, | |
7142 new_class, mode) | |
7143 && reload_adjust_reg_for_temp (&third_reload_reg, NULL, | |
7144 new_t_class, mode)) | |
7145 { | |
7146 second_reload_reg = intermediate; | |
7147 tertiary_icode = sri2.icode; | |
7148 } | |
7149 else | |
7150 oldequiv = old, real_oldequiv = real_old; | |
7151 } | |
7152 else | |
7153 /* This could be handled more intelligently too. */ | |
7154 oldequiv = old, real_oldequiv = real_old; | |
7155 } | |
7156 } | |
7157 | |
7158 /* If we still need a secondary reload register, check | |
7159 to see if it is being used as a scratch or intermediate | |
7160 register and generate code appropriately. If we need | |
7161 a scratch register, use REAL_OLDEQUIV since the form of | |
7162 the insn may depend on the actual address if it is | |
7163 a MEM. */ | |
7164 | |
7165 if (second_reload_reg) | |
7166 { | |
7167 if (icode != CODE_FOR_nothing) | |
7168 { | |
7169 /* We'd have to add extra code to handle this case. */ | |
7170 gcc_assert (!third_reload_reg); | |
7171 | |
7172 emit_insn (GEN_FCN (icode) (reloadreg, real_oldequiv, | |
7173 second_reload_reg)); | |
7174 special = 1; | |
7175 } | |
7176 else | |
7177 { | |
7178 /* See if we need a scratch register to load the | |
7179 intermediate register (a tertiary reload). */ | |
7180 if (tertiary_icode != CODE_FOR_nothing) | |
7181 { | |
7182 emit_insn ((GEN_FCN (tertiary_icode) | |
7183 (second_reload_reg, real_oldequiv, | |
7184 third_reload_reg))); | |
7185 } | |
7186 else if (third_reload_reg) | |
7187 { | |
7188 gen_reload (third_reload_reg, real_oldequiv, | |
7189 rl->opnum, | |
7190 rl->when_needed); | |
7191 gen_reload (second_reload_reg, third_reload_reg, | |
7192 rl->opnum, | |
7193 rl->when_needed); | |
7194 } | |
7195 else | |
7196 gen_reload (second_reload_reg, real_oldequiv, | |
7197 rl->opnum, | |
7198 rl->when_needed); | |
7199 | |
7200 oldequiv = second_reload_reg; | |
7201 } | |
7202 } | |
7203 } | |
7204 | |
7205 if (! special && ! rtx_equal_p (reloadreg, oldequiv)) | |
7206 { | |
7207 rtx real_oldequiv = oldequiv; | |
7208 | |
7209 if ((REG_P (oldequiv) | |
7210 && REGNO (oldequiv) >= FIRST_PSEUDO_REGISTER | |
7211 && (reg_equiv_memory_loc[REGNO (oldequiv)] != 0 | |
7212 || reg_equiv_constant[REGNO (oldequiv)] != 0)) | |
7213 || (GET_CODE (oldequiv) == SUBREG | |
7214 && REG_P (SUBREG_REG (oldequiv)) | |
7215 && (REGNO (SUBREG_REG (oldequiv)) | |
7216 >= FIRST_PSEUDO_REGISTER) | |
7217 && ((reg_equiv_memory_loc | |
7218 [REGNO (SUBREG_REG (oldequiv))] != 0) | |
7219 || (reg_equiv_constant | |
7220 [REGNO (SUBREG_REG (oldequiv))] != 0))) | |
7221 || (CONSTANT_P (oldequiv) | |
7222 && (PREFERRED_RELOAD_CLASS (oldequiv, | |
7223 REGNO_REG_CLASS (REGNO (reloadreg))) | |
7224 == NO_REGS))) | |
7225 real_oldequiv = rl->in; | |
7226 gen_reload (reloadreg, real_oldequiv, rl->opnum, | |
7227 rl->when_needed); | |
7228 } | |
7229 | |
7230 if (flag_non_call_exceptions) | |
7231 copy_eh_notes (insn, get_insns ()); | |
7232 | |
7233 /* End this sequence. */ | |
7234 *where = get_insns (); | |
7235 end_sequence (); | |
7236 | |
7237 /* Update reload_override_in so that delete_address_reloads_1 | |
7238 can see the actual register usage. */ | |
7239 if (oldequiv_reg) | |
7240 reload_override_in[j] = oldequiv; | |
7241 } | |
7242 | |
7243 /* Generate insns to for the output reload RL, which is for the insn described | |
7244 by CHAIN and has the number J. */ | |
7245 static void | |
7246 emit_output_reload_insns (struct insn_chain *chain, struct reload *rl, | |
7247 int j) | |
7248 { | |
7249 rtx reloadreg; | |
7250 rtx insn = chain->insn; | |
7251 int special = 0; | |
7252 rtx old = rl->out; | |
7253 enum machine_mode mode; | |
7254 rtx p; | |
7255 rtx rl_reg_rtx; | |
7256 | |
7257 if (rl->when_needed == RELOAD_OTHER) | |
7258 start_sequence (); | |
7259 else | |
7260 push_to_sequence (output_reload_insns[rl->opnum]); | |
7261 | |
7262 rl_reg_rtx = reload_reg_rtx_for_output[j]; | |
7263 mode = GET_MODE (rl_reg_rtx); | |
7264 | |
7265 reloadreg = rl_reg_rtx; | |
7266 | |
7267 /* If we need two reload regs, set RELOADREG to the intermediate | |
7268 one, since it will be stored into OLD. We might need a secondary | |
7269 register only for an input reload, so check again here. */ | |
7270 | |
7271 if (rl->secondary_out_reload >= 0) | |
7272 { | |
7273 rtx real_old = old; | |
7274 int secondary_reload = rl->secondary_out_reload; | |
7275 int tertiary_reload = rld[secondary_reload].secondary_out_reload; | |
7276 | |
7277 if (REG_P (old) && REGNO (old) >= FIRST_PSEUDO_REGISTER | |
7278 && reg_equiv_mem[REGNO (old)] != 0) | |
7279 real_old = reg_equiv_mem[REGNO (old)]; | |
7280 | |
7281 if (secondary_reload_class (0, rl->rclass, mode, real_old) != NO_REGS) | |
7282 { | |
7283 rtx second_reloadreg = reloadreg; | |
7284 reloadreg = rld[secondary_reload].reg_rtx; | |
7285 | |
7286 /* See if RELOADREG is to be used as a scratch register | |
7287 or as an intermediate register. */ | |
7288 if (rl->secondary_out_icode != CODE_FOR_nothing) | |
7289 { | |
7290 /* We'd have to add extra code to handle this case. */ | |
7291 gcc_assert (tertiary_reload < 0); | |
7292 | |
7293 emit_insn ((GEN_FCN (rl->secondary_out_icode) | |
7294 (real_old, second_reloadreg, reloadreg))); | |
7295 special = 1; | |
7296 } | |
7297 else | |
7298 { | |
7299 /* See if we need both a scratch and intermediate reload | |
7300 register. */ | |
7301 | |
7302 enum insn_code tertiary_icode | |
7303 = rld[secondary_reload].secondary_out_icode; | |
7304 | |
7305 /* We'd have to add more code for quartary reloads. */ | |
7306 gcc_assert (tertiary_reload < 0 | |
7307 || rld[tertiary_reload].secondary_out_reload < 0); | |
7308 | |
7309 if (GET_MODE (reloadreg) != mode) | |
7310 reloadreg = reload_adjust_reg_for_mode (reloadreg, mode); | |
7311 | |
7312 if (tertiary_icode != CODE_FOR_nothing) | |
7313 { | |
7314 rtx third_reloadreg = rld[tertiary_reload].reg_rtx; | |
7315 rtx tem; | |
7316 | |
7317 /* Copy primary reload reg to secondary reload reg. | |
7318 (Note that these have been swapped above, then | |
7319 secondary reload reg to OLD using our insn.) */ | |
7320 | |
7321 /* If REAL_OLD is a paradoxical SUBREG, remove it | |
7322 and try to put the opposite SUBREG on | |
7323 RELOADREG. */ | |
7324 if (GET_CODE (real_old) == SUBREG | |
7325 && (GET_MODE_SIZE (GET_MODE (real_old)) | |
7326 > GET_MODE_SIZE (GET_MODE (SUBREG_REG (real_old)))) | |
7327 && 0 != (tem = gen_lowpart_common | |
7328 (GET_MODE (SUBREG_REG (real_old)), | |
7329 reloadreg))) | |
7330 real_old = SUBREG_REG (real_old), reloadreg = tem; | |
7331 | |
7332 gen_reload (reloadreg, second_reloadreg, | |
7333 rl->opnum, rl->when_needed); | |
7334 emit_insn ((GEN_FCN (tertiary_icode) | |
7335 (real_old, reloadreg, third_reloadreg))); | |
7336 special = 1; | |
7337 } | |
7338 | |
7339 else | |
7340 { | |
7341 /* Copy between the reload regs here and then to | |
7342 OUT later. */ | |
7343 | |
7344 gen_reload (reloadreg, second_reloadreg, | |
7345 rl->opnum, rl->when_needed); | |
7346 if (tertiary_reload >= 0) | |
7347 { | |
7348 rtx third_reloadreg = rld[tertiary_reload].reg_rtx; | |
7349 | |
7350 gen_reload (third_reloadreg, reloadreg, | |
7351 rl->opnum, rl->when_needed); | |
7352 reloadreg = third_reloadreg; | |
7353 } | |
7354 } | |
7355 } | |
7356 } | |
7357 } | |
7358 | |
7359 /* Output the last reload insn. */ | |
7360 if (! special) | |
7361 { | |
7362 rtx set; | |
7363 | |
7364 /* Don't output the last reload if OLD is not the dest of | |
7365 INSN and is in the src and is clobbered by INSN. */ | |
7366 if (! flag_expensive_optimizations | |
7367 || !REG_P (old) | |
7368 || !(set = single_set (insn)) | |
7369 || rtx_equal_p (old, SET_DEST (set)) | |
7370 || !reg_mentioned_p (old, SET_SRC (set)) | |
7371 || !((REGNO (old) < FIRST_PSEUDO_REGISTER) | |
7372 && regno_clobbered_p (REGNO (old), insn, rl->mode, 0))) | |
7373 gen_reload (old, reloadreg, rl->opnum, | |
7374 rl->when_needed); | |
7375 } | |
7376 | |
7377 /* Look at all insns we emitted, just to be safe. */ | |
7378 for (p = get_insns (); p; p = NEXT_INSN (p)) | |
7379 if (INSN_P (p)) | |
7380 { | |
7381 rtx pat = PATTERN (p); | |
7382 | |
7383 /* If this output reload doesn't come from a spill reg, | |
7384 clear any memory of reloaded copies of the pseudo reg. | |
7385 If this output reload comes from a spill reg, | |
7386 reg_has_output_reload will make this do nothing. */ | |
7387 note_stores (pat, forget_old_reloads_1, NULL); | |
7388 | |
7389 if (reg_mentioned_p (rl_reg_rtx, pat)) | |
7390 { | |
7391 rtx set = single_set (insn); | |
7392 if (reload_spill_index[j] < 0 | |
7393 && set | |
7394 && SET_SRC (set) == rl_reg_rtx) | |
7395 { | |
7396 int src = REGNO (SET_SRC (set)); | |
7397 | |
7398 reload_spill_index[j] = src; | |
7399 SET_HARD_REG_BIT (reg_is_output_reload, src); | |
7400 if (find_regno_note (insn, REG_DEAD, src)) | |
7401 SET_HARD_REG_BIT (reg_reloaded_died, src); | |
7402 } | |
7403 if (HARD_REGISTER_P (rl_reg_rtx)) | |
7404 { | |
7405 int s = rl->secondary_out_reload; | |
7406 set = single_set (p); | |
7407 /* If this reload copies only to the secondary reload | |
7408 register, the secondary reload does the actual | |
7409 store. */ | |
7410 if (s >= 0 && set == NULL_RTX) | |
7411 /* We can't tell what function the secondary reload | |
7412 has and where the actual store to the pseudo is | |
7413 made; leave new_spill_reg_store alone. */ | |
7414 ; | |
7415 else if (s >= 0 | |
7416 && SET_SRC (set) == rl_reg_rtx | |
7417 && SET_DEST (set) == rld[s].reg_rtx) | |
7418 { | |
7419 /* Usually the next instruction will be the | |
7420 secondary reload insn; if we can confirm | |
7421 that it is, setting new_spill_reg_store to | |
7422 that insn will allow an extra optimization. */ | |
7423 rtx s_reg = rld[s].reg_rtx; | |
7424 rtx next = NEXT_INSN (p); | |
7425 rld[s].out = rl->out; | |
7426 rld[s].out_reg = rl->out_reg; | |
7427 set = single_set (next); | |
7428 if (set && SET_SRC (set) == s_reg | |
7429 && ! new_spill_reg_store[REGNO (s_reg)]) | |
7430 { | |
7431 SET_HARD_REG_BIT (reg_is_output_reload, | |
7432 REGNO (s_reg)); | |
7433 new_spill_reg_store[REGNO (s_reg)] = next; | |
7434 } | |
7435 } | |
7436 else | |
7437 new_spill_reg_store[REGNO (rl_reg_rtx)] = p; | |
7438 } | |
7439 } | |
7440 } | |
7441 | |
7442 if (rl->when_needed == RELOAD_OTHER) | |
7443 { | |
7444 emit_insn (other_output_reload_insns[rl->opnum]); | |
7445 other_output_reload_insns[rl->opnum] = get_insns (); | |
7446 } | |
7447 else | |
7448 output_reload_insns[rl->opnum] = get_insns (); | |
7449 | |
7450 if (flag_non_call_exceptions) | |
7451 copy_eh_notes (insn, get_insns ()); | |
7452 | |
7453 end_sequence (); | |
7454 } | |
7455 | |
7456 /* Do input reloading for reload RL, which is for the insn described by CHAIN | |
7457 and has the number J. */ | |
7458 static void | |
7459 do_input_reload (struct insn_chain *chain, struct reload *rl, int j) | |
7460 { | |
7461 rtx insn = chain->insn; | |
7462 rtx old = (rl->in && MEM_P (rl->in) | |
7463 ? rl->in_reg : rl->in); | |
7464 rtx reg_rtx = rl->reg_rtx; | |
7465 | |
7466 if (old && reg_rtx) | |
7467 { | |
7468 enum machine_mode mode; | |
7469 | |
7470 /* Determine the mode to reload in. | |
7471 This is very tricky because we have three to choose from. | |
7472 There is the mode the insn operand wants (rl->inmode). | |
7473 There is the mode of the reload register RELOADREG. | |
7474 There is the intrinsic mode of the operand, which we could find | |
7475 by stripping some SUBREGs. | |
7476 It turns out that RELOADREG's mode is irrelevant: | |
7477 we can change that arbitrarily. | |
7478 | |
7479 Consider (SUBREG:SI foo:QI) as an operand that must be SImode; | |
7480 then the reload reg may not support QImode moves, so use SImode. | |
7481 If foo is in memory due to spilling a pseudo reg, this is safe, | |
7482 because the QImode value is in the least significant part of a | |
7483 slot big enough for a SImode. If foo is some other sort of | |
7484 memory reference, then it is impossible to reload this case, | |
7485 so previous passes had better make sure this never happens. | |
7486 | |
7487 Then consider a one-word union which has SImode and one of its | |
7488 members is a float, being fetched as (SUBREG:SF union:SI). | |
7489 We must fetch that as SFmode because we could be loading into | |
7490 a float-only register. In this case OLD's mode is correct. | |
7491 | |
7492 Consider an immediate integer: it has VOIDmode. Here we need | |
7493 to get a mode from something else. | |
7494 | |
7495 In some cases, there is a fourth mode, the operand's | |
7496 containing mode. If the insn specifies a containing mode for | |
7497 this operand, it overrides all others. | |
7498 | |
7499 I am not sure whether the algorithm here is always right, | |
7500 but it does the right things in those cases. */ | |
7501 | |
7502 mode = GET_MODE (old); | |
7503 if (mode == VOIDmode) | |
7504 mode = rl->inmode; | |
7505 | |
7506 /* We cannot use gen_lowpart_common since it can do the wrong thing | |
7507 when REG_RTX has a multi-word mode. Note that REG_RTX must | |
7508 always be a REG here. */ | |
7509 if (GET_MODE (reg_rtx) != mode) | |
7510 reg_rtx = reload_adjust_reg_for_mode (reg_rtx, mode); | |
7511 } | |
7512 reload_reg_rtx_for_input[j] = reg_rtx; | |
7513 | |
7514 if (old != 0 | |
7515 /* AUTO_INC reloads need to be handled even if inherited. We got an | |
7516 AUTO_INC reload if reload_out is set but reload_out_reg isn't. */ | |
7517 && (! reload_inherited[j] || (rl->out && ! rl->out_reg)) | |
7518 && ! rtx_equal_p (reg_rtx, old) | |
7519 && reg_rtx != 0) | |
7520 emit_input_reload_insns (chain, rld + j, old, j); | |
7521 | |
7522 /* When inheriting a wider reload, we have a MEM in rl->in, | |
7523 e.g. inheriting a SImode output reload for | |
7524 (mem:HI (plus:SI (reg:SI 14 fp) (const_int 10))) */ | |
7525 if (optimize && reload_inherited[j] && rl->in | |
7526 && MEM_P (rl->in) | |
7527 && MEM_P (rl->in_reg) | |
7528 && reload_spill_index[j] >= 0 | |
7529 && TEST_HARD_REG_BIT (reg_reloaded_valid, reload_spill_index[j])) | |
7530 rl->in = regno_reg_rtx[reg_reloaded_contents[reload_spill_index[j]]]; | |
7531 | |
7532 /* If we are reloading a register that was recently stored in with an | |
7533 output-reload, see if we can prove there was | |
7534 actually no need to store the old value in it. */ | |
7535 | |
7536 if (optimize | |
7537 && (reload_inherited[j] || reload_override_in[j]) | |
7538 && reg_rtx | |
7539 && REG_P (reg_rtx) | |
7540 && spill_reg_store[REGNO (reg_rtx)] != 0 | |
7541 #if 0 | |
7542 /* There doesn't seem to be any reason to restrict this to pseudos | |
7543 and doing so loses in the case where we are copying from a | |
7544 register of the wrong class. */ | |
7545 && !HARD_REGISTER_P (spill_reg_stored_to[REGNO (reg_rtx)]) | |
7546 #endif | |
7547 /* The insn might have already some references to stackslots | |
7548 replaced by MEMs, while reload_out_reg still names the | |
7549 original pseudo. */ | |
7550 && (dead_or_set_p (insn, spill_reg_stored_to[REGNO (reg_rtx)]) | |
7551 || rtx_equal_p (spill_reg_stored_to[REGNO (reg_rtx)], rl->out_reg))) | |
7552 delete_output_reload (insn, j, REGNO (reg_rtx), reg_rtx); | |
7553 } | |
7554 | |
7555 /* Do output reloading for reload RL, which is for the insn described by | |
7556 CHAIN and has the number J. | |
7557 ??? At some point we need to support handling output reloads of | |
7558 JUMP_INSNs or insns that set cc0. */ | |
7559 static void | |
7560 do_output_reload (struct insn_chain *chain, struct reload *rl, int j) | |
7561 { | |
7562 rtx note, old; | |
7563 rtx insn = chain->insn; | |
7564 /* If this is an output reload that stores something that is | |
7565 not loaded in this same reload, see if we can eliminate a previous | |
7566 store. */ | |
7567 rtx pseudo = rl->out_reg; | |
7568 rtx reg_rtx = rl->reg_rtx; | |
7569 | |
7570 if (rl->out && reg_rtx) | |
7571 { | |
7572 enum machine_mode mode; | |
7573 | |
7574 /* Determine the mode to reload in. | |
7575 See comments above (for input reloading). */ | |
7576 mode = GET_MODE (rl->out); | |
7577 if (mode == VOIDmode) | |
7578 { | |
7579 /* VOIDmode should never happen for an output. */ | |
7580 if (asm_noperands (PATTERN (insn)) < 0) | |
7581 /* It's the compiler's fault. */ | |
7582 fatal_insn ("VOIDmode on an output", insn); | |
7583 error_for_asm (insn, "output operand is constant in %<asm%>"); | |
7584 /* Prevent crash--use something we know is valid. */ | |
7585 mode = word_mode; | |
7586 rl->out = gen_rtx_REG (mode, REGNO (reg_rtx)); | |
7587 } | |
7588 if (GET_MODE (reg_rtx) != mode) | |
7589 reg_rtx = reload_adjust_reg_for_mode (reg_rtx, mode); | |
7590 } | |
7591 reload_reg_rtx_for_output[j] = reg_rtx; | |
7592 | |
7593 if (pseudo | |
7594 && optimize | |
7595 && REG_P (pseudo) | |
7596 && ! rtx_equal_p (rl->in_reg, pseudo) | |
7597 && REGNO (pseudo) >= FIRST_PSEUDO_REGISTER | |
7598 && reg_last_reload_reg[REGNO (pseudo)]) | |
7599 { | |
7600 int pseudo_no = REGNO (pseudo); | |
7601 int last_regno = REGNO (reg_last_reload_reg[pseudo_no]); | |
7602 | |
7603 /* We don't need to test full validity of last_regno for | |
7604 inherit here; we only want to know if the store actually | |
7605 matches the pseudo. */ | |
7606 if (TEST_HARD_REG_BIT (reg_reloaded_valid, last_regno) | |
7607 && reg_reloaded_contents[last_regno] == pseudo_no | |
7608 && spill_reg_store[last_regno] | |
7609 && rtx_equal_p (pseudo, spill_reg_stored_to[last_regno])) | |
7610 delete_output_reload (insn, j, last_regno, reg_rtx); | |
7611 } | |
7612 | |
7613 old = rl->out_reg; | |
7614 if (old == 0 | |
7615 || reg_rtx == 0 | |
7616 || rtx_equal_p (old, reg_rtx)) | |
7617 return; | |
7618 | |
7619 /* An output operand that dies right away does need a reload, | |
7620 but need not be copied from it. Show the new location in the | |
7621 REG_UNUSED note. */ | |
7622 if ((REG_P (old) || GET_CODE (old) == SCRATCH) | |
7623 && (note = find_reg_note (insn, REG_UNUSED, old)) != 0) | |
7624 { | |
7625 XEXP (note, 0) = reg_rtx; | |
7626 return; | |
7627 } | |
7628 /* Likewise for a SUBREG of an operand that dies. */ | |
7629 else if (GET_CODE (old) == SUBREG | |
7630 && REG_P (SUBREG_REG (old)) | |
7631 && 0 != (note = find_reg_note (insn, REG_UNUSED, | |
7632 SUBREG_REG (old)))) | |
7633 { | |
7634 XEXP (note, 0) = gen_lowpart_common (GET_MODE (old), reg_rtx); | |
7635 return; | |
7636 } | |
7637 else if (GET_CODE (old) == SCRATCH) | |
7638 /* If we aren't optimizing, there won't be a REG_UNUSED note, | |
7639 but we don't want to make an output reload. */ | |
7640 return; | |
7641 | |
7642 /* If is a JUMP_INSN, we can't support output reloads yet. */ | |
7643 gcc_assert (NONJUMP_INSN_P (insn)); | |
7644 | |
7645 emit_output_reload_insns (chain, rld + j, j); | |
7646 } | |
7647 | |
7648 /* A reload copies values of MODE from register SRC to register DEST. | |
7649 Return true if it can be treated for inheritance purposes like a | |
7650 group of reloads, each one reloading a single hard register. The | |
7651 caller has already checked that (reg:MODE SRC) and (reg:MODE DEST) | |
7652 occupy the same number of hard registers. */ | |
7653 | |
7654 static bool | |
7655 inherit_piecemeal_p (int dest ATTRIBUTE_UNUSED, | |
7656 int src ATTRIBUTE_UNUSED, | |
7657 enum machine_mode mode ATTRIBUTE_UNUSED) | |
7658 { | |
7659 #ifdef CANNOT_CHANGE_MODE_CLASS | |
7660 return (!REG_CANNOT_CHANGE_MODE_P (dest, mode, reg_raw_mode[dest]) | |
7661 && !REG_CANNOT_CHANGE_MODE_P (src, mode, reg_raw_mode[src])); | |
7662 #else | |
7663 return true; | |
7664 #endif | |
7665 } | |
7666 | |
7667 /* Output insns to reload values in and out of the chosen reload regs. */ | |
7668 | |
7669 static void | |
7670 emit_reload_insns (struct insn_chain *chain) | |
7671 { | |
7672 rtx insn = chain->insn; | |
7673 | |
7674 int j; | |
7675 | |
7676 CLEAR_HARD_REG_SET (reg_reloaded_died); | |
7677 | |
7678 for (j = 0; j < reload_n_operands; j++) | |
7679 input_reload_insns[j] = input_address_reload_insns[j] | |
7680 = inpaddr_address_reload_insns[j] | |
7681 = output_reload_insns[j] = output_address_reload_insns[j] | |
7682 = outaddr_address_reload_insns[j] | |
7683 = other_output_reload_insns[j] = 0; | |
7684 other_input_address_reload_insns = 0; | |
7685 other_input_reload_insns = 0; | |
7686 operand_reload_insns = 0; | |
7687 other_operand_reload_insns = 0; | |
7688 | |
7689 /* Dump reloads into the dump file. */ | |
7690 if (dump_file) | |
7691 { | |
7692 fprintf (dump_file, "\nReloads for insn # %d\n", INSN_UID (insn)); | |
7693 debug_reload_to_stream (dump_file); | |
7694 } | |
7695 | |
7696 /* Now output the instructions to copy the data into and out of the | |
7697 reload registers. Do these in the order that the reloads were reported, | |
7698 since reloads of base and index registers precede reloads of operands | |
7699 and the operands may need the base and index registers reloaded. */ | |
7700 | |
7701 for (j = 0; j < n_reloads; j++) | |
7702 { | |
7703 if (rld[j].reg_rtx && HARD_REGISTER_P (rld[j].reg_rtx)) | |
7704 { | |
7705 unsigned int i; | |
7706 | |
7707 for (i = REGNO (rld[j].reg_rtx); i < END_REGNO (rld[j].reg_rtx); i++) | |
7708 new_spill_reg_store[i] = 0; | |
7709 } | |
7710 | |
7711 do_input_reload (chain, rld + j, j); | |
7712 do_output_reload (chain, rld + j, j); | |
7713 } | |
7714 | |
7715 /* Now write all the insns we made for reloads in the order expected by | |
7716 the allocation functions. Prior to the insn being reloaded, we write | |
7717 the following reloads: | |
7718 | |
7719 RELOAD_FOR_OTHER_ADDRESS reloads for input addresses. | |
7720 | |
7721 RELOAD_OTHER reloads. | |
7722 | |
7723 For each operand, any RELOAD_FOR_INPADDR_ADDRESS reloads followed | |
7724 by any RELOAD_FOR_INPUT_ADDRESS reloads followed by the | |
7725 RELOAD_FOR_INPUT reload for the operand. | |
7726 | |
7727 RELOAD_FOR_OPADDR_ADDRS reloads. | |
7728 | |
7729 RELOAD_FOR_OPERAND_ADDRESS reloads. | |
7730 | |
7731 After the insn being reloaded, we write the following: | |
7732 | |
7733 For each operand, any RELOAD_FOR_OUTADDR_ADDRESS reloads followed | |
7734 by any RELOAD_FOR_OUTPUT_ADDRESS reload followed by the | |
7735 RELOAD_FOR_OUTPUT reload, followed by any RELOAD_OTHER output | |
7736 reloads for the operand. The RELOAD_OTHER output reloads are | |
7737 output in descending order by reload number. */ | |
7738 | |
7739 emit_insn_before (other_input_address_reload_insns, insn); | |
7740 emit_insn_before (other_input_reload_insns, insn); | |
7741 | |
7742 for (j = 0; j < reload_n_operands; j++) | |
7743 { | |
7744 emit_insn_before (inpaddr_address_reload_insns[j], insn); | |
7745 emit_insn_before (input_address_reload_insns[j], insn); | |
7746 emit_insn_before (input_reload_insns[j], insn); | |
7747 } | |
7748 | |
7749 emit_insn_before (other_operand_reload_insns, insn); | |
7750 emit_insn_before (operand_reload_insns, insn); | |
7751 | |
7752 for (j = 0; j < reload_n_operands; j++) | |
7753 { | |
7754 rtx x = emit_insn_after (outaddr_address_reload_insns[j], insn); | |
7755 x = emit_insn_after (output_address_reload_insns[j], x); | |
7756 x = emit_insn_after (output_reload_insns[j], x); | |
7757 emit_insn_after (other_output_reload_insns[j], x); | |
7758 } | |
7759 | |
7760 /* For all the spill regs newly reloaded in this instruction, | |
7761 record what they were reloaded from, so subsequent instructions | |
7762 can inherit the reloads. | |
7763 | |
7764 Update spill_reg_store for the reloads of this insn. | |
7765 Copy the elements that were updated in the loop above. */ | |
7766 | |
7767 for (j = 0; j < n_reloads; j++) | |
7768 { | |
7769 int r = reload_order[j]; | |
7770 int i = reload_spill_index[r]; | |
7771 | |
7772 /* If this is a non-inherited input reload from a pseudo, we must | |
7773 clear any memory of a previous store to the same pseudo. Only do | |
7774 something if there will not be an output reload for the pseudo | |
7775 being reloaded. */ | |
7776 if (rld[r].in_reg != 0 | |
7777 && ! (reload_inherited[r] || reload_override_in[r])) | |
7778 { | |
7779 rtx reg = rld[r].in_reg; | |
7780 | |
7781 if (GET_CODE (reg) == SUBREG) | |
7782 reg = SUBREG_REG (reg); | |
7783 | |
7784 if (REG_P (reg) | |
7785 && REGNO (reg) >= FIRST_PSEUDO_REGISTER | |
7786 && !REGNO_REG_SET_P (®_has_output_reload, REGNO (reg))) | |
7787 { | |
7788 int nregno = REGNO (reg); | |
7789 | |
7790 if (reg_last_reload_reg[nregno]) | |
7791 { | |
7792 int last_regno = REGNO (reg_last_reload_reg[nregno]); | |
7793 | |
7794 if (reg_reloaded_contents[last_regno] == nregno) | |
7795 spill_reg_store[last_regno] = 0; | |
7796 } | |
7797 } | |
7798 } | |
7799 | |
7800 /* I is nonneg if this reload used a register. | |
7801 If rld[r].reg_rtx is 0, this is an optional reload | |
7802 that we opted to ignore. */ | |
7803 | |
7804 if (i >= 0 && rld[r].reg_rtx != 0) | |
7805 { | |
7806 int nr = hard_regno_nregs[i][GET_MODE (rld[r].reg_rtx)]; | |
7807 int k; | |
7808 | |
7809 /* For a multi register reload, we need to check if all or part | |
7810 of the value lives to the end. */ | |
7811 for (k = 0; k < nr; k++) | |
7812 if (reload_reg_reaches_end_p (i + k, rld[r].opnum, | |
7813 rld[r].when_needed)) | |
7814 CLEAR_HARD_REG_BIT (reg_reloaded_valid, i + k); | |
7815 | |
7816 /* Maybe the spill reg contains a copy of reload_out. */ | |
7817 if (rld[r].out != 0 | |
7818 && (REG_P (rld[r].out) | |
7819 #ifdef AUTO_INC_DEC | |
7820 || ! rld[r].out_reg | |
7821 #endif | |
7822 || REG_P (rld[r].out_reg))) | |
7823 { | |
7824 rtx reg; | |
7825 enum machine_mode mode; | |
7826 int regno, nregs; | |
7827 | |
7828 reg = reload_reg_rtx_for_output[r]; | |
7829 mode = GET_MODE (reg); | |
7830 regno = REGNO (reg); | |
7831 nregs = hard_regno_nregs[regno][mode]; | |
7832 if (reload_regs_reach_end_p (regno, nregs, rld[r].opnum, | |
7833 rld[r].when_needed)) | |
7834 { | |
7835 rtx out = (REG_P (rld[r].out) | |
7836 ? rld[r].out | |
7837 : rld[r].out_reg | |
7838 ? rld[r].out_reg | |
7839 /* AUTO_INC */ : XEXP (rld[r].in_reg, 0)); | |
7840 int out_regno = REGNO (out); | |
7841 int out_nregs = (!HARD_REGISTER_NUM_P (out_regno) ? 1 | |
7842 : hard_regno_nregs[out_regno][mode]); | |
7843 bool piecemeal; | |
7844 | |
7845 spill_reg_store[regno] = new_spill_reg_store[regno]; | |
7846 spill_reg_stored_to[regno] = out; | |
7847 reg_last_reload_reg[out_regno] = reg; | |
7848 | |
7849 piecemeal = (HARD_REGISTER_NUM_P (out_regno) | |
7850 && nregs == out_nregs | |
7851 && inherit_piecemeal_p (out_regno, regno, mode)); | |
7852 | |
7853 /* If OUT_REGNO is a hard register, it may occupy more than | |
7854 one register. If it does, say what is in the | |
7855 rest of the registers assuming that both registers | |
7856 agree on how many words the object takes. If not, | |
7857 invalidate the subsequent registers. */ | |
7858 | |
7859 if (HARD_REGISTER_NUM_P (out_regno)) | |
7860 for (k = 1; k < out_nregs; k++) | |
7861 reg_last_reload_reg[out_regno + k] | |
7862 = (piecemeal ? regno_reg_rtx[regno + k] : 0); | |
7863 | |
7864 /* Now do the inverse operation. */ | |
7865 for (k = 0; k < nregs; k++) | |
7866 { | |
7867 CLEAR_HARD_REG_BIT (reg_reloaded_dead, regno + k); | |
7868 reg_reloaded_contents[regno + k] | |
7869 = (!HARD_REGISTER_NUM_P (out_regno) || !piecemeal | |
7870 ? out_regno | |
7871 : out_regno + k); | |
7872 reg_reloaded_insn[regno + k] = insn; | |
7873 SET_HARD_REG_BIT (reg_reloaded_valid, regno + k); | |
7874 if (HARD_REGNO_CALL_PART_CLOBBERED (regno + k, mode)) | |
7875 SET_HARD_REG_BIT (reg_reloaded_call_part_clobbered, | |
7876 regno + k); | |
7877 else | |
7878 CLEAR_HARD_REG_BIT (reg_reloaded_call_part_clobbered, | |
7879 regno + k); | |
7880 } | |
7881 } | |
7882 } | |
7883 /* Maybe the spill reg contains a copy of reload_in. Only do | |
7884 something if there will not be an output reload for | |
7885 the register being reloaded. */ | |
7886 else if (rld[r].out_reg == 0 | |
7887 && rld[r].in != 0 | |
7888 && ((REG_P (rld[r].in) | |
7889 && !HARD_REGISTER_P (rld[r].in) | |
7890 && !REGNO_REG_SET_P (®_has_output_reload, | |
7891 REGNO (rld[r].in))) | |
7892 || (REG_P (rld[r].in_reg) | |
7893 && !REGNO_REG_SET_P (®_has_output_reload, | |
7894 REGNO (rld[r].in_reg)))) | |
7895 && !reg_set_p (reload_reg_rtx_for_input[r], PATTERN (insn))) | |
7896 { | |
7897 rtx reg; | |
7898 enum machine_mode mode; | |
7899 int regno, nregs; | |
7900 | |
7901 reg = reload_reg_rtx_for_input[r]; | |
7902 mode = GET_MODE (reg); | |
7903 regno = REGNO (reg); | |
7904 nregs = hard_regno_nregs[regno][mode]; | |
7905 if (reload_regs_reach_end_p (regno, nregs, rld[r].opnum, | |
7906 rld[r].when_needed)) | |
7907 { | |
7908 int in_regno; | |
7909 int in_nregs; | |
7910 rtx in; | |
7911 bool piecemeal; | |
7912 | |
7913 if (REG_P (rld[r].in) | |
7914 && REGNO (rld[r].in) >= FIRST_PSEUDO_REGISTER) | |
7915 in = rld[r].in; | |
7916 else if (REG_P (rld[r].in_reg)) | |
7917 in = rld[r].in_reg; | |
7918 else | |
7919 in = XEXP (rld[r].in_reg, 0); | |
7920 in_regno = REGNO (in); | |
7921 | |
7922 in_nregs = (!HARD_REGISTER_NUM_P (in_regno) ? 1 | |
7923 : hard_regno_nregs[in_regno][mode]); | |
7924 | |
7925 reg_last_reload_reg[in_regno] = reg; | |
7926 | |
7927 piecemeal = (HARD_REGISTER_NUM_P (in_regno) | |
7928 && nregs == in_nregs | |
7929 && inherit_piecemeal_p (regno, in_regno, mode)); | |
7930 | |
7931 if (HARD_REGISTER_NUM_P (in_regno)) | |
7932 for (k = 1; k < in_nregs; k++) | |
7933 reg_last_reload_reg[in_regno + k] | |
7934 = (piecemeal ? regno_reg_rtx[regno + k] : 0); | |
7935 | |
7936 /* Unless we inherited this reload, show we haven't | |
7937 recently done a store. | |
7938 Previous stores of inherited auto_inc expressions | |
7939 also have to be discarded. */ | |
7940 if (! reload_inherited[r] | |
7941 || (rld[r].out && ! rld[r].out_reg)) | |
7942 spill_reg_store[regno] = 0; | |
7943 | |
7944 for (k = 0; k < nregs; k++) | |
7945 { | |
7946 CLEAR_HARD_REG_BIT (reg_reloaded_dead, regno + k); | |
7947 reg_reloaded_contents[regno + k] | |
7948 = (!HARD_REGISTER_NUM_P (in_regno) || !piecemeal | |
7949 ? in_regno | |
7950 : in_regno + k); | |
7951 reg_reloaded_insn[regno + k] = insn; | |
7952 SET_HARD_REG_BIT (reg_reloaded_valid, regno + k); | |
7953 if (HARD_REGNO_CALL_PART_CLOBBERED (regno + k, mode)) | |
7954 SET_HARD_REG_BIT (reg_reloaded_call_part_clobbered, | |
7955 regno + k); | |
7956 else | |
7957 CLEAR_HARD_REG_BIT (reg_reloaded_call_part_clobbered, | |
7958 regno + k); | |
7959 } | |
7960 } | |
7961 } | |
7962 } | |
7963 | |
7964 /* The following if-statement was #if 0'd in 1.34 (or before...). | |
7965 It's reenabled in 1.35 because supposedly nothing else | |
7966 deals with this problem. */ | |
7967 | |
7968 /* If a register gets output-reloaded from a non-spill register, | |
7969 that invalidates any previous reloaded copy of it. | |
7970 But forget_old_reloads_1 won't get to see it, because | |
7971 it thinks only about the original insn. So invalidate it here. | |
7972 Also do the same thing for RELOAD_OTHER constraints where the | |
7973 output is discarded. */ | |
7974 if (i < 0 | |
7975 && ((rld[r].out != 0 | |
7976 && (REG_P (rld[r].out) | |
7977 || (MEM_P (rld[r].out) | |
7978 && REG_P (rld[r].out_reg)))) | |
7979 || (rld[r].out == 0 && rld[r].out_reg | |
7980 && REG_P (rld[r].out_reg)))) | |
7981 { | |
7982 rtx out = ((rld[r].out && REG_P (rld[r].out)) | |
7983 ? rld[r].out : rld[r].out_reg); | |
7984 int out_regno = REGNO (out); | |
7985 enum machine_mode mode = GET_MODE (out); | |
7986 | |
7987 /* REG_RTX is now set or clobbered by the main instruction. | |
7988 As the comment above explains, forget_old_reloads_1 only | |
7989 sees the original instruction, and there is no guarantee | |
7990 that the original instruction also clobbered REG_RTX. | |
7991 For example, if find_reloads sees that the input side of | |
7992 a matched operand pair dies in this instruction, it may | |
7993 use the input register as the reload register. | |
7994 | |
7995 Calling forget_old_reloads_1 is a waste of effort if | |
7996 REG_RTX is also the output register. | |
7997 | |
7998 If we know that REG_RTX holds the value of a pseudo | |
7999 register, the code after the call will record that fact. */ | |
8000 if (rld[r].reg_rtx && rld[r].reg_rtx != out) | |
8001 forget_old_reloads_1 (rld[r].reg_rtx, NULL_RTX, NULL); | |
8002 | |
8003 if (!HARD_REGISTER_NUM_P (out_regno)) | |
8004 { | |
8005 rtx src_reg, store_insn = NULL_RTX; | |
8006 | |
8007 reg_last_reload_reg[out_regno] = 0; | |
8008 | |
8009 /* If we can find a hard register that is stored, record | |
8010 the storing insn so that we may delete this insn with | |
8011 delete_output_reload. */ | |
8012 src_reg = reload_reg_rtx_for_output[r]; | |
8013 | |
8014 /* If this is an optional reload, try to find the source reg | |
8015 from an input reload. */ | |
8016 if (! src_reg) | |
8017 { | |
8018 rtx set = single_set (insn); | |
8019 if (set && SET_DEST (set) == rld[r].out) | |
8020 { | |
8021 int k; | |
8022 | |
8023 src_reg = SET_SRC (set); | |
8024 store_insn = insn; | |
8025 for (k = 0; k < n_reloads; k++) | |
8026 { | |
8027 if (rld[k].in == src_reg) | |
8028 { | |
8029 src_reg = reload_reg_rtx_for_input[k]; | |
8030 break; | |
8031 } | |
8032 } | |
8033 } | |
8034 } | |
8035 else | |
8036 store_insn = new_spill_reg_store[REGNO (src_reg)]; | |
8037 if (src_reg && REG_P (src_reg) | |
8038 && REGNO (src_reg) < FIRST_PSEUDO_REGISTER) | |
8039 { | |
8040 int src_regno, src_nregs, k; | |
8041 rtx note; | |
8042 | |
8043 gcc_assert (GET_MODE (src_reg) == mode); | |
8044 src_regno = REGNO (src_reg); | |
8045 src_nregs = hard_regno_nregs[src_regno][mode]; | |
8046 /* The place where to find a death note varies with | |
8047 PRESERVE_DEATH_INFO_REGNO_P . The condition is not | |
8048 necessarily checked exactly in the code that moves | |
8049 notes, so just check both locations. */ | |
8050 note = find_regno_note (insn, REG_DEAD, src_regno); | |
8051 if (! note && store_insn) | |
8052 note = find_regno_note (store_insn, REG_DEAD, src_regno); | |
8053 for (k = 0; k < src_nregs; k++) | |
8054 { | |
8055 spill_reg_store[src_regno + k] = store_insn; | |
8056 spill_reg_stored_to[src_regno + k] = out; | |
8057 reg_reloaded_contents[src_regno + k] = out_regno; | |
8058 reg_reloaded_insn[src_regno + k] = store_insn; | |
8059 CLEAR_HARD_REG_BIT (reg_reloaded_dead, src_regno + k); | |
8060 SET_HARD_REG_BIT (reg_reloaded_valid, src_regno + k); | |
8061 if (HARD_REGNO_CALL_PART_CLOBBERED (src_regno + k, | |
8062 mode)) | |
8063 SET_HARD_REG_BIT (reg_reloaded_call_part_clobbered, | |
8064 src_regno + k); | |
8065 else | |
8066 CLEAR_HARD_REG_BIT (reg_reloaded_call_part_clobbered, | |
8067 src_regno + k); | |
8068 SET_HARD_REG_BIT (reg_is_output_reload, src_regno + k); | |
8069 if (note) | |
8070 SET_HARD_REG_BIT (reg_reloaded_died, src_regno); | |
8071 else | |
8072 CLEAR_HARD_REG_BIT (reg_reloaded_died, src_regno); | |
8073 } | |
8074 reg_last_reload_reg[out_regno] = src_reg; | |
8075 /* We have to set reg_has_output_reload here, or else | |
8076 forget_old_reloads_1 will clear reg_last_reload_reg | |
8077 right away. */ | |
8078 SET_REGNO_REG_SET (®_has_output_reload, | |
8079 out_regno); | |
8080 } | |
8081 } | |
8082 else | |
8083 { | |
8084 int k, out_nregs = hard_regno_nregs[out_regno][mode]; | |
8085 | |
8086 for (k = 0; k < out_nregs; k++) | |
8087 reg_last_reload_reg[out_regno + k] = 0; | |
8088 } | |
8089 } | |
8090 } | |
8091 IOR_HARD_REG_SET (reg_reloaded_dead, reg_reloaded_died); | |
8092 } | |
8093 | |
8094 /* Go through the motions to emit INSN and test if it is strictly valid. | |
8095 Return the emitted insn if valid, else return NULL. */ | |
8096 | |
8097 static rtx | |
8098 emit_insn_if_valid_for_reload (rtx insn) | |
8099 { | |
8100 rtx last = get_last_insn (); | |
8101 int code; | |
8102 | |
8103 insn = emit_insn (insn); | |
8104 code = recog_memoized (insn); | |
8105 | |
8106 if (code >= 0) | |
8107 { | |
8108 extract_insn (insn); | |
8109 /* We want constrain operands to treat this insn strictly in its | |
8110 validity determination, i.e., the way it would after reload has | |
8111 completed. */ | |
8112 if (constrain_operands (1)) | |
8113 return insn; | |
8114 } | |
8115 | |
8116 delete_insns_since (last); | |
8117 return NULL; | |
8118 } | |
8119 | |
8120 /* Emit code to perform a reload from IN (which may be a reload register) to | |
8121 OUT (which may also be a reload register). IN or OUT is from operand | |
8122 OPNUM with reload type TYPE. | |
8123 | |
8124 Returns first insn emitted. */ | |
8125 | |
8126 static rtx | |
8127 gen_reload (rtx out, rtx in, int opnum, enum reload_type type) | |
8128 { | |
8129 rtx last = get_last_insn (); | |
8130 rtx tem; | |
8131 | |
8132 /* If IN is a paradoxical SUBREG, remove it and try to put the | |
8133 opposite SUBREG on OUT. Likewise for a paradoxical SUBREG on OUT. */ | |
8134 if (GET_CODE (in) == SUBREG | |
8135 && (GET_MODE_SIZE (GET_MODE (in)) | |
8136 > GET_MODE_SIZE (GET_MODE (SUBREG_REG (in)))) | |
8137 && (tem = gen_lowpart_common (GET_MODE (SUBREG_REG (in)), out)) != 0) | |
8138 in = SUBREG_REG (in), out = tem; | |
8139 else if (GET_CODE (out) == SUBREG | |
8140 && (GET_MODE_SIZE (GET_MODE (out)) | |
8141 > GET_MODE_SIZE (GET_MODE (SUBREG_REG (out)))) | |
8142 && (tem = gen_lowpart_common (GET_MODE (SUBREG_REG (out)), in)) != 0) | |
8143 out = SUBREG_REG (out), in = tem; | |
8144 | |
8145 /* How to do this reload can get quite tricky. Normally, we are being | |
8146 asked to reload a simple operand, such as a MEM, a constant, or a pseudo | |
8147 register that didn't get a hard register. In that case we can just | |
8148 call emit_move_insn. | |
8149 | |
8150 We can also be asked to reload a PLUS that adds a register or a MEM to | |
8151 another register, constant or MEM. This can occur during frame pointer | |
8152 elimination and while reloading addresses. This case is handled by | |
8153 trying to emit a single insn to perform the add. If it is not valid, | |
8154 we use a two insn sequence. | |
8155 | |
8156 Or we can be asked to reload an unary operand that was a fragment of | |
8157 an addressing mode, into a register. If it isn't recognized as-is, | |
8158 we try making the unop operand and the reload-register the same: | |
8159 (set reg:X (unop:X expr:Y)) | |
8160 -> (set reg:Y expr:Y) (set reg:X (unop:X reg:Y)). | |
8161 | |
8162 Finally, we could be called to handle an 'o' constraint by putting | |
8163 an address into a register. In that case, we first try to do this | |
8164 with a named pattern of "reload_load_address". If no such pattern | |
8165 exists, we just emit a SET insn and hope for the best (it will normally | |
8166 be valid on machines that use 'o'). | |
8167 | |
8168 This entire process is made complex because reload will never | |
8169 process the insns we generate here and so we must ensure that | |
8170 they will fit their constraints and also by the fact that parts of | |
8171 IN might be being reloaded separately and replaced with spill registers. | |
8172 Because of this, we are, in some sense, just guessing the right approach | |
8173 here. The one listed above seems to work. | |
8174 | |
8175 ??? At some point, this whole thing needs to be rethought. */ | |
8176 | |
8177 if (GET_CODE (in) == PLUS | |
8178 && (REG_P (XEXP (in, 0)) | |
8179 || GET_CODE (XEXP (in, 0)) == SUBREG | |
8180 || MEM_P (XEXP (in, 0))) | |
8181 && (REG_P (XEXP (in, 1)) | |
8182 || GET_CODE (XEXP (in, 1)) == SUBREG | |
8183 || CONSTANT_P (XEXP (in, 1)) | |
8184 || MEM_P (XEXP (in, 1)))) | |
8185 { | |
8186 /* We need to compute the sum of a register or a MEM and another | |
8187 register, constant, or MEM, and put it into the reload | |
8188 register. The best possible way of doing this is if the machine | |
8189 has a three-operand ADD insn that accepts the required operands. | |
8190 | |
8191 The simplest approach is to try to generate such an insn and see if it | |
8192 is recognized and matches its constraints. If so, it can be used. | |
8193 | |
8194 It might be better not to actually emit the insn unless it is valid, | |
8195 but we need to pass the insn as an operand to `recog' and | |
8196 `extract_insn' and it is simpler to emit and then delete the insn if | |
8197 not valid than to dummy things up. */ | |
8198 | |
8199 rtx op0, op1, tem, insn; | |
8200 int code; | |
8201 | |
8202 op0 = find_replacement (&XEXP (in, 0)); | |
8203 op1 = find_replacement (&XEXP (in, 1)); | |
8204 | |
8205 /* Since constraint checking is strict, commutativity won't be | |
8206 checked, so we need to do that here to avoid spurious failure | |
8207 if the add instruction is two-address and the second operand | |
8208 of the add is the same as the reload reg, which is frequently | |
8209 the case. If the insn would be A = B + A, rearrange it so | |
8210 it will be A = A + B as constrain_operands expects. */ | |
8211 | |
8212 if (REG_P (XEXP (in, 1)) | |
8213 && REGNO (out) == REGNO (XEXP (in, 1))) | |
8214 tem = op0, op0 = op1, op1 = tem; | |
8215 | |
8216 if (op0 != XEXP (in, 0) || op1 != XEXP (in, 1)) | |
8217 in = gen_rtx_PLUS (GET_MODE (in), op0, op1); | |
8218 | |
8219 insn = emit_insn_if_valid_for_reload (gen_rtx_SET (VOIDmode, out, in)); | |
8220 if (insn) | |
8221 return insn; | |
8222 | |
8223 /* If that failed, we must use a conservative two-insn sequence. | |
8224 | |
8225 Use a move to copy one operand into the reload register. Prefer | |
8226 to reload a constant, MEM or pseudo since the move patterns can | |
8227 handle an arbitrary operand. If OP1 is not a constant, MEM or | |
8228 pseudo and OP1 is not a valid operand for an add instruction, then | |
8229 reload OP1. | |
8230 | |
8231 After reloading one of the operands into the reload register, add | |
8232 the reload register to the output register. | |
8233 | |
8234 If there is another way to do this for a specific machine, a | |
8235 DEFINE_PEEPHOLE should be specified that recognizes the sequence | |
8236 we emit below. */ | |
8237 | |
8238 code = (int) optab_handler (add_optab, GET_MODE (out))->insn_code; | |
8239 | |
8240 if (CONSTANT_P (op1) || MEM_P (op1) || GET_CODE (op1) == SUBREG | |
8241 || (REG_P (op1) | |
8242 && REGNO (op1) >= FIRST_PSEUDO_REGISTER) | |
8243 || (code != CODE_FOR_nothing | |
8244 && ! ((*insn_data[code].operand[2].predicate) | |
8245 (op1, insn_data[code].operand[2].mode)))) | |
8246 tem = op0, op0 = op1, op1 = tem; | |
8247 | |
8248 gen_reload (out, op0, opnum, type); | |
8249 | |
8250 /* If OP0 and OP1 are the same, we can use OUT for OP1. | |
8251 This fixes a problem on the 32K where the stack pointer cannot | |
8252 be used as an operand of an add insn. */ | |
8253 | |
8254 if (rtx_equal_p (op0, op1)) | |
8255 op1 = out; | |
8256 | |
8257 insn = emit_insn_if_valid_for_reload (gen_add2_insn (out, op1)); | |
8258 if (insn) | |
8259 { | |
8260 /* Add a REG_EQUIV note so that find_equiv_reg can find it. */ | |
8261 set_unique_reg_note (insn, REG_EQUIV, in); | |
8262 return insn; | |
8263 } | |
8264 | |
8265 /* If that failed, copy the address register to the reload register. | |
8266 Then add the constant to the reload register. */ | |
8267 | |
8268 gcc_assert (!reg_overlap_mentioned_p (out, op0)); | |
8269 gen_reload (out, op1, opnum, type); | |
8270 insn = emit_insn (gen_add2_insn (out, op0)); | |
8271 set_unique_reg_note (insn, REG_EQUIV, in); | |
8272 } | |
8273 | |
8274 #ifdef SECONDARY_MEMORY_NEEDED | |
8275 /* If we need a memory location to do the move, do it that way. */ | |
8276 else if ((REG_P (in) | |
8277 || (GET_CODE (in) == SUBREG && REG_P (SUBREG_REG (in)))) | |
8278 && reg_or_subregno (in) < FIRST_PSEUDO_REGISTER | |
8279 && (REG_P (out) | |
8280 || (GET_CODE (out) == SUBREG && REG_P (SUBREG_REG (out)))) | |
8281 && reg_or_subregno (out) < FIRST_PSEUDO_REGISTER | |
8282 && SECONDARY_MEMORY_NEEDED (REGNO_REG_CLASS (reg_or_subregno (in)), | |
8283 REGNO_REG_CLASS (reg_or_subregno (out)), | |
8284 GET_MODE (out))) | |
8285 { | |
8286 /* Get the memory to use and rewrite both registers to its mode. */ | |
8287 rtx loc = get_secondary_mem (in, GET_MODE (out), opnum, type); | |
8288 | |
8289 if (GET_MODE (loc) != GET_MODE (out)) | |
8290 out = gen_rtx_REG (GET_MODE (loc), REGNO (out)); | |
8291 | |
8292 if (GET_MODE (loc) != GET_MODE (in)) | |
8293 in = gen_rtx_REG (GET_MODE (loc), REGNO (in)); | |
8294 | |
8295 gen_reload (loc, in, opnum, type); | |
8296 gen_reload (out, loc, opnum, type); | |
8297 } | |
8298 #endif | |
8299 else if (REG_P (out) && UNARY_P (in)) | |
8300 { | |
8301 rtx insn; | |
8302 rtx op1; | |
8303 rtx out_moded; | |
8304 rtx set; | |
8305 | |
8306 op1 = find_replacement (&XEXP (in, 0)); | |
8307 if (op1 != XEXP (in, 0)) | |
8308 in = gen_rtx_fmt_e (GET_CODE (in), GET_MODE (in), op1); | |
8309 | |
8310 /* First, try a plain SET. */ | |
8311 set = emit_insn_if_valid_for_reload (gen_rtx_SET (VOIDmode, out, in)); | |
8312 if (set) | |
8313 return set; | |
8314 | |
8315 /* If that failed, move the inner operand to the reload | |
8316 register, and try the same unop with the inner expression | |
8317 replaced with the reload register. */ | |
8318 | |
8319 if (GET_MODE (op1) != GET_MODE (out)) | |
8320 out_moded = gen_rtx_REG (GET_MODE (op1), REGNO (out)); | |
8321 else | |
8322 out_moded = out; | |
8323 | |
8324 gen_reload (out_moded, op1, opnum, type); | |
8325 | |
8326 insn | |
8327 = gen_rtx_SET (VOIDmode, out, | |
8328 gen_rtx_fmt_e (GET_CODE (in), GET_MODE (in), | |
8329 out_moded)); | |
8330 insn = emit_insn_if_valid_for_reload (insn); | |
8331 if (insn) | |
8332 { | |
8333 set_unique_reg_note (insn, REG_EQUIV, in); | |
8334 return insn; | |
8335 } | |
8336 | |
8337 fatal_insn ("Failure trying to reload:", set); | |
8338 } | |
8339 /* If IN is a simple operand, use gen_move_insn. */ | |
8340 else if (OBJECT_P (in) || GET_CODE (in) == SUBREG) | |
8341 { | |
8342 tem = emit_insn (gen_move_insn (out, in)); | |
8343 /* IN may contain a LABEL_REF, if so add a REG_LABEL_OPERAND note. */ | |
8344 mark_jump_label (in, tem, 0); | |
8345 } | |
8346 | |
8347 #ifdef HAVE_reload_load_address | |
8348 else if (HAVE_reload_load_address) | |
8349 emit_insn (gen_reload_load_address (out, in)); | |
8350 #endif | |
8351 | |
8352 /* Otherwise, just write (set OUT IN) and hope for the best. */ | |
8353 else | |
8354 emit_insn (gen_rtx_SET (VOIDmode, out, in)); | |
8355 | |
8356 /* Return the first insn emitted. | |
8357 We can not just return get_last_insn, because there may have | |
8358 been multiple instructions emitted. Also note that gen_move_insn may | |
8359 emit more than one insn itself, so we can not assume that there is one | |
8360 insn emitted per emit_insn_before call. */ | |
8361 | |
8362 return last ? NEXT_INSN (last) : get_insns (); | |
8363 } | |
8364 | |
8365 /* Delete a previously made output-reload whose result we now believe | |
8366 is not needed. First we double-check. | |
8367 | |
8368 INSN is the insn now being processed. | |
8369 LAST_RELOAD_REG is the hard register number for which we want to delete | |
8370 the last output reload. | |
8371 J is the reload-number that originally used REG. The caller has made | |
8372 certain that reload J doesn't use REG any longer for input. | |
8373 NEW_RELOAD_REG is reload register that reload J is using for REG. */ | |
8374 | |
8375 static void | |
8376 delete_output_reload (rtx insn, int j, int last_reload_reg, rtx new_reload_reg) | |
8377 { | |
8378 rtx output_reload_insn = spill_reg_store[last_reload_reg]; | |
8379 rtx reg = spill_reg_stored_to[last_reload_reg]; | |
8380 int k; | |
8381 int n_occurrences; | |
8382 int n_inherited = 0; | |
8383 rtx i1; | |
8384 rtx substed; | |
8385 | |
8386 /* It is possible that this reload has been only used to set another reload | |
8387 we eliminated earlier and thus deleted this instruction too. */ | |
8388 if (INSN_DELETED_P (output_reload_insn)) | |
8389 return; | |
8390 | |
8391 /* Get the raw pseudo-register referred to. */ | |
8392 | |
8393 while (GET_CODE (reg) == SUBREG) | |
8394 reg = SUBREG_REG (reg); | |
8395 substed = reg_equiv_memory_loc[REGNO (reg)]; | |
8396 | |
8397 /* This is unsafe if the operand occurs more often in the current | |
8398 insn than it is inherited. */ | |
8399 for (k = n_reloads - 1; k >= 0; k--) | |
8400 { | |
8401 rtx reg2 = rld[k].in; | |
8402 if (! reg2) | |
8403 continue; | |
8404 if (MEM_P (reg2) || reload_override_in[k]) | |
8405 reg2 = rld[k].in_reg; | |
8406 #ifdef AUTO_INC_DEC | |
8407 if (rld[k].out && ! rld[k].out_reg) | |
8408 reg2 = XEXP (rld[k].in_reg, 0); | |
8409 #endif | |
8410 while (GET_CODE (reg2) == SUBREG) | |
8411 reg2 = SUBREG_REG (reg2); | |
8412 if (rtx_equal_p (reg2, reg)) | |
8413 { | |
8414 if (reload_inherited[k] || reload_override_in[k] || k == j) | |
8415 n_inherited++; | |
8416 else | |
8417 return; | |
8418 } | |
8419 } | |
8420 n_occurrences = count_occurrences (PATTERN (insn), reg, 0); | |
8421 if (CALL_P (insn) && CALL_INSN_FUNCTION_USAGE (insn)) | |
8422 n_occurrences += count_occurrences (CALL_INSN_FUNCTION_USAGE (insn), | |
8423 reg, 0); | |
8424 if (substed) | |
8425 n_occurrences += count_occurrences (PATTERN (insn), | |
8426 eliminate_regs (substed, 0, | |
8427 NULL_RTX), 0); | |
8428 for (i1 = reg_equiv_alt_mem_list[REGNO (reg)]; i1; i1 = XEXP (i1, 1)) | |
8429 { | |
8430 gcc_assert (!rtx_equal_p (XEXP (i1, 0), substed)); | |
8431 n_occurrences += count_occurrences (PATTERN (insn), XEXP (i1, 0), 0); | |
8432 } | |
8433 if (n_occurrences > n_inherited) | |
8434 return; | |
8435 | |
8436 /* If the pseudo-reg we are reloading is no longer referenced | |
8437 anywhere between the store into it and here, | |
8438 and we're within the same basic block, then the value can only | |
8439 pass through the reload reg and end up here. | |
8440 Otherwise, give up--return. */ | |
8441 for (i1 = NEXT_INSN (output_reload_insn); | |
8442 i1 != insn; i1 = NEXT_INSN (i1)) | |
8443 { | |
8444 if (NOTE_INSN_BASIC_BLOCK_P (i1)) | |
8445 return; | |
8446 if ((NONJUMP_INSN_P (i1) || CALL_P (i1)) | |
8447 && reg_mentioned_p (reg, PATTERN (i1))) | |
8448 { | |
8449 /* If this is USE in front of INSN, we only have to check that | |
8450 there are no more references than accounted for by inheritance. */ | |
8451 while (NONJUMP_INSN_P (i1) && GET_CODE (PATTERN (i1)) == USE) | |
8452 { | |
8453 n_occurrences += rtx_equal_p (reg, XEXP (PATTERN (i1), 0)) != 0; | |
8454 i1 = NEXT_INSN (i1); | |
8455 } | |
8456 if (n_occurrences <= n_inherited && i1 == insn) | |
8457 break; | |
8458 return; | |
8459 } | |
8460 } | |
8461 | |
8462 /* We will be deleting the insn. Remove the spill reg information. */ | |
8463 for (k = hard_regno_nregs[last_reload_reg][GET_MODE (reg)]; k-- > 0; ) | |
8464 { | |
8465 spill_reg_store[last_reload_reg + k] = 0; | |
8466 spill_reg_stored_to[last_reload_reg + k] = 0; | |
8467 } | |
8468 | |
8469 /* The caller has already checked that REG dies or is set in INSN. | |
8470 It has also checked that we are optimizing, and thus some | |
8471 inaccuracies in the debugging information are acceptable. | |
8472 So we could just delete output_reload_insn. But in some cases | |
8473 we can improve the debugging information without sacrificing | |
8474 optimization - maybe even improving the code: See if the pseudo | |
8475 reg has been completely replaced with reload regs. If so, delete | |
8476 the store insn and forget we had a stack slot for the pseudo. */ | |
8477 if (rld[j].out != rld[j].in | |
8478 && REG_N_DEATHS (REGNO (reg)) == 1 | |
8479 && REG_N_SETS (REGNO (reg)) == 1 | |
8480 && REG_BASIC_BLOCK (REGNO (reg)) >= NUM_FIXED_BLOCKS | |
8481 && find_regno_note (insn, REG_DEAD, REGNO (reg))) | |
8482 { | |
8483 rtx i2; | |
8484 | |
8485 /* We know that it was used only between here and the beginning of | |
8486 the current basic block. (We also know that the last use before | |
8487 INSN was the output reload we are thinking of deleting, but never | |
8488 mind that.) Search that range; see if any ref remains. */ | |
8489 for (i2 = PREV_INSN (insn); i2; i2 = PREV_INSN (i2)) | |
8490 { | |
8491 rtx set = single_set (i2); | |
8492 | |
8493 /* Uses which just store in the pseudo don't count, | |
8494 since if they are the only uses, they are dead. */ | |
8495 if (set != 0 && SET_DEST (set) == reg) | |
8496 continue; | |
8497 if (LABEL_P (i2) | |
8498 || JUMP_P (i2)) | |
8499 break; | |
8500 if ((NONJUMP_INSN_P (i2) || CALL_P (i2)) | |
8501 && reg_mentioned_p (reg, PATTERN (i2))) | |
8502 { | |
8503 /* Some other ref remains; just delete the output reload we | |
8504 know to be dead. */ | |
8505 delete_address_reloads (output_reload_insn, insn); | |
8506 delete_insn (output_reload_insn); | |
8507 return; | |
8508 } | |
8509 } | |
8510 | |
8511 /* Delete the now-dead stores into this pseudo. Note that this | |
8512 loop also takes care of deleting output_reload_insn. */ | |
8513 for (i2 = PREV_INSN (insn); i2; i2 = PREV_INSN (i2)) | |
8514 { | |
8515 rtx set = single_set (i2); | |
8516 | |
8517 if (set != 0 && SET_DEST (set) == reg) | |
8518 { | |
8519 delete_address_reloads (i2, insn); | |
8520 delete_insn (i2); | |
8521 } | |
8522 if (LABEL_P (i2) | |
8523 || JUMP_P (i2)) | |
8524 break; | |
8525 } | |
8526 | |
8527 /* For the debugging info, say the pseudo lives in this reload reg. */ | |
8528 reg_renumber[REGNO (reg)] = REGNO (new_reload_reg); | |
8529 if (ira_conflicts_p) | |
8530 /* Inform IRA about the change. */ | |
8531 ira_mark_allocation_change (REGNO (reg)); | |
8532 alter_reg (REGNO (reg), -1, false); | |
8533 } | |
8534 else | |
8535 { | |
8536 delete_address_reloads (output_reload_insn, insn); | |
8537 delete_insn (output_reload_insn); | |
8538 } | |
8539 } | |
8540 | |
8541 /* We are going to delete DEAD_INSN. Recursively delete loads of | |
8542 reload registers used in DEAD_INSN that are not used till CURRENT_INSN. | |
8543 CURRENT_INSN is being reloaded, so we have to check its reloads too. */ | |
8544 static void | |
8545 delete_address_reloads (rtx dead_insn, rtx current_insn) | |
8546 { | |
8547 rtx set = single_set (dead_insn); | |
8548 rtx set2, dst, prev, next; | |
8549 if (set) | |
8550 { | |
8551 rtx dst = SET_DEST (set); | |
8552 if (MEM_P (dst)) | |
8553 delete_address_reloads_1 (dead_insn, XEXP (dst, 0), current_insn); | |
8554 } | |
8555 /* If we deleted the store from a reloaded post_{in,de}c expression, | |
8556 we can delete the matching adds. */ | |
8557 prev = PREV_INSN (dead_insn); | |
8558 next = NEXT_INSN (dead_insn); | |
8559 if (! prev || ! next) | |
8560 return; | |
8561 set = single_set (next); | |
8562 set2 = single_set (prev); | |
8563 if (! set || ! set2 | |
8564 || GET_CODE (SET_SRC (set)) != PLUS || GET_CODE (SET_SRC (set2)) != PLUS | |
8565 || GET_CODE (XEXP (SET_SRC (set), 1)) != CONST_INT | |
8566 || GET_CODE (XEXP (SET_SRC (set2), 1)) != CONST_INT) | |
8567 return; | |
8568 dst = SET_DEST (set); | |
8569 if (! rtx_equal_p (dst, SET_DEST (set2)) | |
8570 || ! rtx_equal_p (dst, XEXP (SET_SRC (set), 0)) | |
8571 || ! rtx_equal_p (dst, XEXP (SET_SRC (set2), 0)) | |
8572 || (INTVAL (XEXP (SET_SRC (set), 1)) | |
8573 != -INTVAL (XEXP (SET_SRC (set2), 1)))) | |
8574 return; | |
8575 delete_related_insns (prev); | |
8576 delete_related_insns (next); | |
8577 } | |
8578 | |
8579 /* Subfunction of delete_address_reloads: process registers found in X. */ | |
8580 static void | |
8581 delete_address_reloads_1 (rtx dead_insn, rtx x, rtx current_insn) | |
8582 { | |
8583 rtx prev, set, dst, i2; | |
8584 int i, j; | |
8585 enum rtx_code code = GET_CODE (x); | |
8586 | |
8587 if (code != REG) | |
8588 { | |
8589 const char *fmt = GET_RTX_FORMAT (code); | |
8590 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
8591 { | |
8592 if (fmt[i] == 'e') | |
8593 delete_address_reloads_1 (dead_insn, XEXP (x, i), current_insn); | |
8594 else if (fmt[i] == 'E') | |
8595 { | |
8596 for (j = XVECLEN (x, i) - 1; j >= 0; j--) | |
8597 delete_address_reloads_1 (dead_insn, XVECEXP (x, i, j), | |
8598 current_insn); | |
8599 } | |
8600 } | |
8601 return; | |
8602 } | |
8603 | |
8604 if (spill_reg_order[REGNO (x)] < 0) | |
8605 return; | |
8606 | |
8607 /* Scan backwards for the insn that sets x. This might be a way back due | |
8608 to inheritance. */ | |
8609 for (prev = PREV_INSN (dead_insn); prev; prev = PREV_INSN (prev)) | |
8610 { | |
8611 code = GET_CODE (prev); | |
8612 if (code == CODE_LABEL || code == JUMP_INSN) | |
8613 return; | |
8614 if (!INSN_P (prev)) | |
8615 continue; | |
8616 if (reg_set_p (x, PATTERN (prev))) | |
8617 break; | |
8618 if (reg_referenced_p (x, PATTERN (prev))) | |
8619 return; | |
8620 } | |
8621 if (! prev || INSN_UID (prev) < reload_first_uid) | |
8622 return; | |
8623 /* Check that PREV only sets the reload register. */ | |
8624 set = single_set (prev); | |
8625 if (! set) | |
8626 return; | |
8627 dst = SET_DEST (set); | |
8628 if (!REG_P (dst) | |
8629 || ! rtx_equal_p (dst, x)) | |
8630 return; | |
8631 if (! reg_set_p (dst, PATTERN (dead_insn))) | |
8632 { | |
8633 /* Check if DST was used in a later insn - | |
8634 it might have been inherited. */ | |
8635 for (i2 = NEXT_INSN (dead_insn); i2; i2 = NEXT_INSN (i2)) | |
8636 { | |
8637 if (LABEL_P (i2)) | |
8638 break; | |
8639 if (! INSN_P (i2)) | |
8640 continue; | |
8641 if (reg_referenced_p (dst, PATTERN (i2))) | |
8642 { | |
8643 /* If there is a reference to the register in the current insn, | |
8644 it might be loaded in a non-inherited reload. If no other | |
8645 reload uses it, that means the register is set before | |
8646 referenced. */ | |
8647 if (i2 == current_insn) | |
8648 { | |
8649 for (j = n_reloads - 1; j >= 0; j--) | |
8650 if ((rld[j].reg_rtx == dst && reload_inherited[j]) | |
8651 || reload_override_in[j] == dst) | |
8652 return; | |
8653 for (j = n_reloads - 1; j >= 0; j--) | |
8654 if (rld[j].in && rld[j].reg_rtx == dst) | |
8655 break; | |
8656 if (j >= 0) | |
8657 break; | |
8658 } | |
8659 return; | |
8660 } | |
8661 if (JUMP_P (i2)) | |
8662 break; | |
8663 /* If DST is still live at CURRENT_INSN, check if it is used for | |
8664 any reload. Note that even if CURRENT_INSN sets DST, we still | |
8665 have to check the reloads. */ | |
8666 if (i2 == current_insn) | |
8667 { | |
8668 for (j = n_reloads - 1; j >= 0; j--) | |
8669 if ((rld[j].reg_rtx == dst && reload_inherited[j]) | |
8670 || reload_override_in[j] == dst) | |
8671 return; | |
8672 /* ??? We can't finish the loop here, because dst might be | |
8673 allocated to a pseudo in this block if no reload in this | |
8674 block needs any of the classes containing DST - see | |
8675 spill_hard_reg. There is no easy way to tell this, so we | |
8676 have to scan till the end of the basic block. */ | |
8677 } | |
8678 if (reg_set_p (dst, PATTERN (i2))) | |
8679 break; | |
8680 } | |
8681 } | |
8682 delete_address_reloads_1 (prev, SET_SRC (set), current_insn); | |
8683 reg_reloaded_contents[REGNO (dst)] = -1; | |
8684 delete_insn (prev); | |
8685 } | |
8686 | |
8687 /* Output reload-insns to reload VALUE into RELOADREG. | |
8688 VALUE is an autoincrement or autodecrement RTX whose operand | |
8689 is a register or memory location; | |
8690 so reloading involves incrementing that location. | |
8691 IN is either identical to VALUE, or some cheaper place to reload from. | |
8692 | |
8693 INC_AMOUNT is the number to increment or decrement by (always positive). | |
8694 This cannot be deduced from VALUE. | |
8695 | |
8696 Return the instruction that stores into RELOADREG. */ | |
8697 | |
8698 static rtx | |
8699 inc_for_reload (rtx reloadreg, rtx in, rtx value, int inc_amount) | |
8700 { | |
8701 /* REG or MEM to be copied and incremented. */ | |
8702 rtx incloc = find_replacement (&XEXP (value, 0)); | |
8703 /* Nonzero if increment after copying. */ | |
8704 int post = (GET_CODE (value) == POST_DEC || GET_CODE (value) == POST_INC | |
8705 || GET_CODE (value) == POST_MODIFY); | |
8706 rtx last; | |
8707 rtx inc; | |
8708 rtx add_insn; | |
8709 int code; | |
8710 rtx store; | |
8711 rtx real_in = in == value ? incloc : in; | |
8712 | |
8713 /* No hard register is equivalent to this register after | |
8714 inc/dec operation. If REG_LAST_RELOAD_REG were nonzero, | |
8715 we could inc/dec that register as well (maybe even using it for | |
8716 the source), but I'm not sure it's worth worrying about. */ | |
8717 if (REG_P (incloc)) | |
8718 reg_last_reload_reg[REGNO (incloc)] = 0; | |
8719 | |
8720 if (GET_CODE (value) == PRE_MODIFY || GET_CODE (value) == POST_MODIFY) | |
8721 { | |
8722 gcc_assert (GET_CODE (XEXP (value, 1)) == PLUS); | |
8723 inc = find_replacement (&XEXP (XEXP (value, 1), 1)); | |
8724 } | |
8725 else | |
8726 { | |
8727 if (GET_CODE (value) == PRE_DEC || GET_CODE (value) == POST_DEC) | |
8728 inc_amount = -inc_amount; | |
8729 | |
8730 inc = GEN_INT (inc_amount); | |
8731 } | |
8732 | |
8733 /* If this is post-increment, first copy the location to the reload reg. */ | |
8734 if (post && real_in != reloadreg) | |
8735 emit_insn (gen_move_insn (reloadreg, real_in)); | |
8736 | |
8737 if (in == value) | |
8738 { | |
8739 /* See if we can directly increment INCLOC. Use a method similar to | |
8740 that in gen_reload. */ | |
8741 | |
8742 last = get_last_insn (); | |
8743 add_insn = emit_insn (gen_rtx_SET (VOIDmode, incloc, | |
8744 gen_rtx_PLUS (GET_MODE (incloc), | |
8745 incloc, inc))); | |
8746 | |
8747 code = recog_memoized (add_insn); | |
8748 if (code >= 0) | |
8749 { | |
8750 extract_insn (add_insn); | |
8751 if (constrain_operands (1)) | |
8752 { | |
8753 /* If this is a pre-increment and we have incremented the value | |
8754 where it lives, copy the incremented value to RELOADREG to | |
8755 be used as an address. */ | |
8756 | |
8757 if (! post) | |
8758 emit_insn (gen_move_insn (reloadreg, incloc)); | |
8759 | |
8760 return add_insn; | |
8761 } | |
8762 } | |
8763 delete_insns_since (last); | |
8764 } | |
8765 | |
8766 /* If couldn't do the increment directly, must increment in RELOADREG. | |
8767 The way we do this depends on whether this is pre- or post-increment. | |
8768 For pre-increment, copy INCLOC to the reload register, increment it | |
8769 there, then save back. */ | |
8770 | |
8771 if (! post) | |
8772 { | |
8773 if (in != reloadreg) | |
8774 emit_insn (gen_move_insn (reloadreg, real_in)); | |
8775 emit_insn (gen_add2_insn (reloadreg, inc)); | |
8776 store = emit_insn (gen_move_insn (incloc, reloadreg)); | |
8777 } | |
8778 else | |
8779 { | |
8780 /* Postincrement. | |
8781 Because this might be a jump insn or a compare, and because RELOADREG | |
8782 may not be available after the insn in an input reload, we must do | |
8783 the incrementation before the insn being reloaded for. | |
8784 | |
8785 We have already copied IN to RELOADREG. Increment the copy in | |
8786 RELOADREG, save that back, then decrement RELOADREG so it has | |
8787 the original value. */ | |
8788 | |
8789 emit_insn (gen_add2_insn (reloadreg, inc)); | |
8790 store = emit_insn (gen_move_insn (incloc, reloadreg)); | |
8791 if (GET_CODE (inc) == CONST_INT) | |
8792 emit_insn (gen_add2_insn (reloadreg, GEN_INT (-INTVAL (inc)))); | |
8793 else | |
8794 emit_insn (gen_sub2_insn (reloadreg, inc)); | |
8795 } | |
8796 | |
8797 return store; | |
8798 } | |
8799 | |
8800 #ifdef AUTO_INC_DEC | |
8801 static void | |
8802 add_auto_inc_notes (rtx insn, rtx x) | |
8803 { | |
8804 enum rtx_code code = GET_CODE (x); | |
8805 const char *fmt; | |
8806 int i, j; | |
8807 | |
8808 if (code == MEM && auto_inc_p (XEXP (x, 0))) | |
8809 { | |
8810 add_reg_note (insn, REG_INC, XEXP (XEXP (x, 0), 0)); | |
8811 return; | |
8812 } | |
8813 | |
8814 /* Scan all the operand sub-expressions. */ | |
8815 fmt = GET_RTX_FORMAT (code); | |
8816 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--) | |
8817 { | |
8818 if (fmt[i] == 'e') | |
8819 add_auto_inc_notes (insn, XEXP (x, i)); | |
8820 else if (fmt[i] == 'E') | |
8821 for (j = XVECLEN (x, i) - 1; j >= 0; j--) | |
8822 add_auto_inc_notes (insn, XVECEXP (x, i, j)); | |
8823 } | |
8824 } | |
8825 #endif | |
8826 | |
8827 /* Copy EH notes from an insn to its reloads. */ | |
8828 static void | |
8829 copy_eh_notes (rtx insn, rtx x) | |
8830 { | |
8831 rtx eh_note = find_reg_note (insn, REG_EH_REGION, NULL_RTX); | |
8832 if (eh_note) | |
8833 { | |
8834 for (; x != 0; x = NEXT_INSN (x)) | |
8835 { | |
8836 if (may_trap_p (PATTERN (x))) | |
8837 add_reg_note (x, REG_EH_REGION, XEXP (eh_note, 0)); | |
8838 } | |
8839 } | |
8840 } | |
8841 | |
8842 /* This is used by reload pass, that does emit some instructions after | |
8843 abnormal calls moving basic block end, but in fact it wants to emit | |
8844 them on the edge. Looks for abnormal call edges, find backward the | |
8845 proper call and fix the damage. | |
8846 | |
8847 Similar handle instructions throwing exceptions internally. */ | |
8848 void | |
8849 fixup_abnormal_edges (void) | |
8850 { | |
8851 bool inserted = false; | |
8852 basic_block bb; | |
8853 | |
8854 FOR_EACH_BB (bb) | |
8855 { | |
8856 edge e; | |
8857 edge_iterator ei; | |
8858 | |
8859 /* Look for cases we are interested in - calls or instructions causing | |
8860 exceptions. */ | |
8861 FOR_EACH_EDGE (e, ei, bb->succs) | |
8862 { | |
8863 if (e->flags & EDGE_ABNORMAL_CALL) | |
8864 break; | |
8865 if ((e->flags & (EDGE_ABNORMAL | EDGE_EH)) | |
8866 == (EDGE_ABNORMAL | EDGE_EH)) | |
8867 break; | |
8868 } | |
8869 if (e && !CALL_P (BB_END (bb)) | |
8870 && !can_throw_internal (BB_END (bb))) | |
8871 { | |
8872 rtx insn; | |
8873 | |
8874 /* Get past the new insns generated. Allow notes, as the insns | |
8875 may be already deleted. */ | |
8876 insn = BB_END (bb); | |
8877 while ((NONJUMP_INSN_P (insn) || NOTE_P (insn)) | |
8878 && !can_throw_internal (insn) | |
8879 && insn != BB_HEAD (bb)) | |
8880 insn = PREV_INSN (insn); | |
8881 | |
8882 if (CALL_P (insn) || can_throw_internal (insn)) | |
8883 { | |
8884 rtx stop, next; | |
8885 | |
8886 stop = NEXT_INSN (BB_END (bb)); | |
8887 BB_END (bb) = insn; | |
8888 insn = NEXT_INSN (insn); | |
8889 | |
8890 FOR_EACH_EDGE (e, ei, bb->succs) | |
8891 if (e->flags & EDGE_FALLTHRU) | |
8892 break; | |
8893 | |
8894 while (insn && insn != stop) | |
8895 { | |
8896 next = NEXT_INSN (insn); | |
8897 if (INSN_P (insn)) | |
8898 { | |
8899 delete_insn (insn); | |
8900 | |
8901 /* Sometimes there's still the return value USE. | |
8902 If it's placed after a trapping call (i.e. that | |
8903 call is the last insn anyway), we have no fallthru | |
8904 edge. Simply delete this use and don't try to insert | |
8905 on the non-existent edge. */ | |
8906 if (GET_CODE (PATTERN (insn)) != USE) | |
8907 { | |
8908 /* We're not deleting it, we're moving it. */ | |
8909 INSN_DELETED_P (insn) = 0; | |
8910 PREV_INSN (insn) = NULL_RTX; | |
8911 NEXT_INSN (insn) = NULL_RTX; | |
8912 | |
8913 insert_insn_on_edge (insn, e); | |
8914 inserted = true; | |
8915 } | |
8916 } | |
8917 else if (!BARRIER_P (insn)) | |
8918 set_block_for_insn (insn, NULL); | |
8919 insn = next; | |
8920 } | |
8921 } | |
8922 | |
8923 /* It may be that we don't find any such trapping insn. In this | |
8924 case we discovered quite late that the insn that had been | |
8925 marked as can_throw_internal in fact couldn't trap at all. | |
8926 So we should in fact delete the EH edges out of the block. */ | |
8927 else | |
8928 purge_dead_edges (bb); | |
8929 } | |
8930 } | |
8931 | |
8932 /* We've possibly turned single trapping insn into multiple ones. */ | |
8933 if (flag_non_call_exceptions) | |
8934 { | |
8935 sbitmap blocks; | |
8936 blocks = sbitmap_alloc (last_basic_block); | |
8937 sbitmap_ones (blocks); | |
8938 find_many_sub_basic_blocks (blocks); | |
8939 sbitmap_free (blocks); | |
8940 } | |
8941 | |
8942 if (inserted) | |
8943 commit_edge_insertions (); | |
8944 | |
8945 #ifdef ENABLE_CHECKING | |
8946 /* Verify that we didn't turn one trapping insn into many, and that | |
8947 we found and corrected all of the problems wrt fixups on the | |
8948 fallthru edge. */ | |
8949 verify_flow_info (); | |
8950 #endif | |
8951 } |