Mercurial > hg > CbC > CbC_gcc
annotate gcc/init-regs.c @ 86:12b3180c7d07
modify calls.c.
| author | Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> |
|---|---|
| date | Thu, 15 Dec 2011 02:37:13 +0900 |
| parents | 77e2b8dfacca |
| children | 04ced10e8804 |
| rev | line source |
|---|---|
|
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77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
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1 /* Initialization of uninitialized regs. |
|
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
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2 Copyright (C) 2007, 2008, 2009 Free Software Foundation, Inc. |
| 0 | 3 |
| 4 This file is part of GCC. | |
| 5 | |
| 6 GCC is free software; you can redistribute it and/or modify it under | |
| 7 the terms of the GNU General Public License as published by the Free | |
| 8 Software Foundation; either version 3, or (at your option) any later | |
| 9 version. | |
| 10 | |
| 11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY | |
| 12 WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
| 13 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
| 14 for more details. | |
| 15 | |
| 16 You should have received a copy of the GNU General Public License | |
| 17 along with GCC; see the file COPYING3. If not see | |
| 18 <http://www.gnu.org/licenses/>. */ | |
| 19 | |
| 20 #include "config.h" | |
| 21 #include "system.h" | |
| 22 #include "coretypes.h" | |
| 23 #include "tm.h" | |
| 24 #include "tree.h" | |
| 25 #include "rtl.h" | |
| 26 #include "regs.h" | |
| 27 #include "expr.h" | |
| 28 #include "tree-pass.h" | |
| 29 #include "basic-block.h" | |
| 30 #include "flags.h" | |
| 31 #include "df.h" | |
| 32 | |
| 33 /* Check all of the uses of pseudo variables. If any use that is MUST | |
| 34 uninitialized, add a store of 0 immediately before it. For | |
| 35 subregs, this makes combine happy. For full word regs, this makes | |
| 36 other optimizations, like the register allocator and the reg-stack | |
| 37 happy as well as papers over some problems on the arm and other | |
| 38 processors where certain isa constraints cannot be handled by gcc. | |
| 39 These are of the form where two operands to an insn my not be the | |
| 40 same. The ra will only make them the same if they do not | |
| 41 interfere, and this can only happen if one is not initialized. | |
| 42 | |
| 43 There is also the unfortunate consequence that this may mask some | |
| 44 buggy programs where people forget to initialize stack variable. | |
| 45 Any programmer with half a brain would look at the uninitialized | |
| 46 variable warnings. */ | |
| 47 | |
| 48 static void | |
| 49 initialize_uninitialized_regs (void) | |
| 50 { | |
| 51 basic_block bb; | |
| 52 bitmap already_genned = BITMAP_ALLOC (NULL); | |
| 53 | |
| 54 if (optimize == 1) | |
| 55 { | |
| 56 df_live_add_problem (); | |
| 57 df_live_set_all_dirty (); | |
| 58 } | |
| 59 | |
| 60 df_analyze (); | |
| 61 | |
| 62 FOR_EACH_BB (bb) | |
| 63 { | |
| 64 rtx insn; | |
| 65 bitmap lr = DF_LR_IN (bb); | |
| 66 bitmap ur = DF_LIVE_IN (bb); | |
| 67 bitmap_clear (already_genned); | |
| 68 | |
| 69 FOR_BB_INSNS (bb, insn) | |
| 70 { | |
| 71 unsigned int uid = INSN_UID (insn); | |
| 72 df_ref *use_rec; | |
|
55
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
73 if (!NONDEBUG_INSN_P (insn)) |
| 0 | 74 continue; |
| 75 | |
| 76 for (use_rec = DF_INSN_UID_USES (uid); *use_rec; use_rec++) | |
| 77 { | |
| 78 df_ref use = *use_rec; | |
| 79 unsigned int regno = DF_REF_REGNO (use); | |
| 80 | |
| 81 /* Only do this for the pseudos. */ | |
| 82 if (regno < FIRST_PSEUDO_REGISTER) | |
| 83 continue; | |
| 84 | |
| 85 /* Do not generate multiple moves for the same regno. | |
| 86 This is common for sequences of subreg operations. | |
| 87 They would be deleted during combine but there is no | |
| 88 reason to churn the system. */ | |
| 89 if (bitmap_bit_p (already_genned, regno)) | |
| 90 continue; | |
| 91 | |
| 92 /* A use is MUST uninitialized if it reaches the top of | |
| 93 the block from the inside of the block (the lr test) | |
| 94 and no def for it reaches the top of the block from | |
| 95 outside of the block (the ur test). */ | |
| 96 if (bitmap_bit_p (lr, regno) | |
| 97 && (!bitmap_bit_p (ur, regno))) | |
| 98 { | |
| 99 rtx move_insn; | |
| 100 rtx reg = DF_REF_REAL_REG (use); | |
| 101 | |
|
55
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
102 bitmap_set_bit (already_genned, regno); |
| 0 | 103 |
| 104 start_sequence (); | |
| 105 emit_move_insn (reg, CONST0_RTX (GET_MODE (reg))); | |
| 106 move_insn = get_insns (); | |
| 107 end_sequence (); | |
| 108 emit_insn_before (move_insn, insn); | |
| 109 if (dump_file) | |
|
55
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
110 fprintf (dump_file, |
|
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
111 "adding initialization in %s of reg %d at in block %d for insn %d.\n", |
| 0 | 112 current_function_name (), regno, bb->index, uid); |
| 113 } | |
| 114 } | |
| 115 } | |
| 116 } | |
| 117 | |
| 118 if (optimize == 1) | |
| 119 { | |
|
55
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
120 if (dump_file) |
| 0 | 121 df_dump (dump_file); |
| 122 df_remove_problem (df_live); | |
| 123 } | |
| 124 | |
| 125 BITMAP_FREE (already_genned); | |
| 126 } | |
| 127 | |
| 128 static bool | |
| 129 gate_initialize_regs (void) | |
| 130 { | |
| 131 return optimize > 0; | |
| 132 } | |
| 133 | |
| 134 static unsigned int | |
| 135 rest_of_handle_initialize_regs (void) | |
| 136 { | |
| 137 initialize_uninitialized_regs (); | |
| 138 return 0; | |
| 139 } | |
| 140 | |
| 141 struct rtl_opt_pass pass_initialize_regs = | |
| 142 { | |
| 143 { | |
| 144 RTL_PASS, | |
| 145 "init-regs", /* name */ | |
| 146 gate_initialize_regs, /* gate */ | |
| 147 rest_of_handle_initialize_regs, /* execute */ | |
| 148 NULL, /* sub */ | |
| 149 NULL, /* next */ | |
| 150 0, /* static_pass_number */ | |
|
55
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
151 TV_NONE, /* tv_id */ |
| 0 | 152 0, /* properties_required */ |
| 153 0, /* properties_provided */ | |
| 154 0, /* properties_destroyed */ | |
| 155 0, /* todo_flags_start */ | |
| 156 TODO_dump_func | | |
| 157 TODO_df_finish /* todo_flags_finish */ | |
| 158 } | |
| 159 }; |