Mercurial > hg > CbC > CbC_gcc
annotate gcc/convert.c @ 22:0eb6cac880f0
add cbc example of quicksort.
author | kent <kent@cr.ie.u-ryukyu.ac.jp> |
---|---|
date | Tue, 13 Oct 2009 17:15:58 +0900 |
parents | 58ad6c70ea60 |
children | 77e2b8dfacca |
rev | line source |
---|---|
0 | 1 /* Utility routines for data type conversion for GCC. |
2 Copyright (C) 1987, 1988, 1991, 1992, 1993, 1994, 1995, 1997, 1998, | |
3 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 | |
23 /* These routines are somewhat language-independent utility function | |
24 intended to be called by the language-specific convert () functions. */ | |
25 | |
26 #include "config.h" | |
27 #include "system.h" | |
28 #include "coretypes.h" | |
29 #include "tm.h" | |
30 #include "tree.h" | |
31 #include "flags.h" | |
32 #include "convert.h" | |
33 #include "toplev.h" | |
34 #include "langhooks.h" | |
35 #include "real.h" | |
36 #include "fixed-value.h" | |
37 | |
38 /* Convert EXPR to some pointer or reference type TYPE. | |
39 EXPR must be pointer, reference, integer, enumeral, or literal zero; | |
40 in other cases error is called. */ | |
41 | |
42 tree | |
43 convert_to_pointer (tree type, tree expr) | |
44 { | |
45 if (TREE_TYPE (expr) == type) | |
46 return expr; | |
47 | |
48 /* Propagate overflow to the NULL pointer. */ | |
49 if (integer_zerop (expr)) | |
50 return force_fit_type_double (type, 0, 0, 0, TREE_OVERFLOW (expr)); | |
51 | |
52 switch (TREE_CODE (TREE_TYPE (expr))) | |
53 { | |
54 case POINTER_TYPE: | |
55 case REFERENCE_TYPE: | |
56 return fold_build1 (NOP_EXPR, type, expr); | |
57 | |
58 case INTEGER_TYPE: | |
59 case ENUMERAL_TYPE: | |
60 case BOOLEAN_TYPE: | |
61 if (TYPE_PRECISION (TREE_TYPE (expr)) != POINTER_SIZE) | |
62 expr = fold_build1 (NOP_EXPR, | |
63 lang_hooks.types.type_for_size (POINTER_SIZE, 0), | |
64 expr); | |
65 return fold_build1 (CONVERT_EXPR, type, expr); | |
66 | |
67 | |
68 default: | |
69 error ("cannot convert to a pointer type"); | |
70 return convert_to_pointer (type, integer_zero_node); | |
71 } | |
72 } | |
73 | |
74 /* Avoid any floating point extensions from EXP. */ | |
75 tree | |
76 strip_float_extensions (tree exp) | |
77 { | |
78 tree sub, expt, subt; | |
79 | |
80 /* For floating point constant look up the narrowest type that can hold | |
81 it properly and handle it like (type)(narrowest_type)constant. | |
82 This way we can optimize for instance a=a*2.0 where "a" is float | |
83 but 2.0 is double constant. */ | |
84 if (TREE_CODE (exp) == REAL_CST && !DECIMAL_FLOAT_TYPE_P (TREE_TYPE (exp))) | |
85 { | |
86 REAL_VALUE_TYPE orig; | |
87 tree type = NULL; | |
88 | |
89 orig = TREE_REAL_CST (exp); | |
90 if (TYPE_PRECISION (TREE_TYPE (exp)) > TYPE_PRECISION (float_type_node) | |
91 && exact_real_truncate (TYPE_MODE (float_type_node), &orig)) | |
92 type = float_type_node; | |
93 else if (TYPE_PRECISION (TREE_TYPE (exp)) | |
94 > TYPE_PRECISION (double_type_node) | |
95 && exact_real_truncate (TYPE_MODE (double_type_node), &orig)) | |
96 type = double_type_node; | |
97 if (type) | |
98 return build_real (type, real_value_truncate (TYPE_MODE (type), orig)); | |
99 } | |
100 | |
101 if (!CONVERT_EXPR_P (exp)) | |
102 return exp; | |
103 | |
104 sub = TREE_OPERAND (exp, 0); | |
105 subt = TREE_TYPE (sub); | |
106 expt = TREE_TYPE (exp); | |
107 | |
108 if (!FLOAT_TYPE_P (subt)) | |
109 return exp; | |
110 | |
111 if (DECIMAL_FLOAT_TYPE_P (expt) != DECIMAL_FLOAT_TYPE_P (subt)) | |
112 return exp; | |
113 | |
114 if (TYPE_PRECISION (subt) > TYPE_PRECISION (expt)) | |
115 return exp; | |
116 | |
117 return strip_float_extensions (sub); | |
118 } | |
119 | |
120 | |
121 /* Convert EXPR to some floating-point type TYPE. | |
122 | |
123 EXPR must be float, fixed-point, integer, or enumeral; | |
124 in other cases error is called. */ | |
125 | |
126 tree | |
127 convert_to_real (tree type, tree expr) | |
128 { | |
129 enum built_in_function fcode = builtin_mathfn_code (expr); | |
130 tree itype = TREE_TYPE (expr); | |
131 | |
132 /* Disable until we figure out how to decide whether the functions are | |
133 present in runtime. */ | |
134 /* Convert (float)sqrt((double)x) where x is float into sqrtf(x) */ | |
135 if (optimize | |
136 && (TYPE_MODE (type) == TYPE_MODE (double_type_node) | |
137 || TYPE_MODE (type) == TYPE_MODE (float_type_node))) | |
138 { | |
139 switch (fcode) | |
140 { | |
141 #define CASE_MATHFN(FN) case BUILT_IN_##FN: case BUILT_IN_##FN##L: | |
142 CASE_MATHFN (COSH) | |
143 CASE_MATHFN (EXP) | |
144 CASE_MATHFN (EXP10) | |
145 CASE_MATHFN (EXP2) | |
146 CASE_MATHFN (EXPM1) | |
147 CASE_MATHFN (GAMMA) | |
148 CASE_MATHFN (J0) | |
149 CASE_MATHFN (J1) | |
150 CASE_MATHFN (LGAMMA) | |
151 CASE_MATHFN (POW10) | |
152 CASE_MATHFN (SINH) | |
153 CASE_MATHFN (TGAMMA) | |
154 CASE_MATHFN (Y0) | |
155 CASE_MATHFN (Y1) | |
156 /* The above functions may set errno differently with float | |
157 input or output so this transformation is not safe with | |
158 -fmath-errno. */ | |
159 if (flag_errno_math) | |
160 break; | |
161 CASE_MATHFN (ACOS) | |
162 CASE_MATHFN (ACOSH) | |
163 CASE_MATHFN (ASIN) | |
164 CASE_MATHFN (ASINH) | |
165 CASE_MATHFN (ATAN) | |
166 CASE_MATHFN (ATANH) | |
167 CASE_MATHFN (CBRT) | |
168 CASE_MATHFN (COS) | |
169 CASE_MATHFN (ERF) | |
170 CASE_MATHFN (ERFC) | |
171 CASE_MATHFN (FABS) | |
172 CASE_MATHFN (LOG) | |
173 CASE_MATHFN (LOG10) | |
174 CASE_MATHFN (LOG2) | |
175 CASE_MATHFN (LOG1P) | |
176 CASE_MATHFN (LOGB) | |
177 CASE_MATHFN (SIN) | |
178 CASE_MATHFN (SQRT) | |
179 CASE_MATHFN (TAN) | |
180 CASE_MATHFN (TANH) | |
181 #undef CASE_MATHFN | |
182 { | |
183 tree arg0 = strip_float_extensions (CALL_EXPR_ARG (expr, 0)); | |
184 tree newtype = type; | |
185 | |
186 /* We have (outertype)sqrt((innertype)x). Choose the wider mode from | |
187 the both as the safe type for operation. */ | |
188 if (TYPE_PRECISION (TREE_TYPE (arg0)) > TYPE_PRECISION (type)) | |
189 newtype = TREE_TYPE (arg0); | |
190 | |
191 /* Be careful about integer to fp conversions. | |
192 These may overflow still. */ | |
193 if (FLOAT_TYPE_P (TREE_TYPE (arg0)) | |
194 && TYPE_PRECISION (newtype) < TYPE_PRECISION (itype) | |
195 && (TYPE_MODE (newtype) == TYPE_MODE (double_type_node) | |
196 || TYPE_MODE (newtype) == TYPE_MODE (float_type_node))) | |
197 { | |
198 tree fn = mathfn_built_in (newtype, fcode); | |
199 | |
200 if (fn) | |
201 { | |
202 tree arg = fold (convert_to_real (newtype, arg0)); | |
203 expr = build_call_expr (fn, 1, arg); | |
204 if (newtype == type) | |
205 return expr; | |
206 } | |
207 } | |
208 } | |
209 default: | |
210 break; | |
211 } | |
212 } | |
213 if (optimize | |
214 && (((fcode == BUILT_IN_FLOORL | |
215 || fcode == BUILT_IN_CEILL | |
216 || fcode == BUILT_IN_ROUNDL | |
217 || fcode == BUILT_IN_RINTL | |
218 || fcode == BUILT_IN_TRUNCL | |
219 || fcode == BUILT_IN_NEARBYINTL) | |
220 && (TYPE_MODE (type) == TYPE_MODE (double_type_node) | |
221 || TYPE_MODE (type) == TYPE_MODE (float_type_node))) | |
222 || ((fcode == BUILT_IN_FLOOR | |
223 || fcode == BUILT_IN_CEIL | |
224 || fcode == BUILT_IN_ROUND | |
225 || fcode == BUILT_IN_RINT | |
226 || fcode == BUILT_IN_TRUNC | |
227 || fcode == BUILT_IN_NEARBYINT) | |
228 && (TYPE_MODE (type) == TYPE_MODE (float_type_node))))) | |
229 { | |
230 tree fn = mathfn_built_in (type, fcode); | |
231 | |
232 if (fn) | |
233 { | |
234 tree arg = strip_float_extensions (CALL_EXPR_ARG (expr, 0)); | |
235 | |
236 /* Make sure (type)arg0 is an extension, otherwise we could end up | |
237 changing (float)floor(double d) into floorf((float)d), which is | |
238 incorrect because (float)d uses round-to-nearest and can round | |
239 up to the next integer. */ | |
240 if (TYPE_PRECISION (type) >= TYPE_PRECISION (TREE_TYPE (arg))) | |
241 return build_call_expr (fn, 1, fold (convert_to_real (type, arg))); | |
242 } | |
243 } | |
244 | |
245 /* Propagate the cast into the operation. */ | |
246 if (itype != type && FLOAT_TYPE_P (type)) | |
247 switch (TREE_CODE (expr)) | |
248 { | |
249 /* Convert (float)-x into -(float)x. This is safe for | |
250 round-to-nearest rounding mode. */ | |
251 case ABS_EXPR: | |
252 case NEGATE_EXPR: | |
253 if (!flag_rounding_math | |
254 && TYPE_PRECISION (type) < TYPE_PRECISION (TREE_TYPE (expr))) | |
255 return build1 (TREE_CODE (expr), type, | |
256 fold (convert_to_real (type, | |
257 TREE_OPERAND (expr, 0)))); | |
258 break; | |
259 /* Convert (outertype)((innertype0)a+(innertype1)b) | |
260 into ((newtype)a+(newtype)b) where newtype | |
261 is the widest mode from all of these. */ | |
262 case PLUS_EXPR: | |
263 case MINUS_EXPR: | |
264 case MULT_EXPR: | |
265 case RDIV_EXPR: | |
266 { | |
267 tree arg0 = strip_float_extensions (TREE_OPERAND (expr, 0)); | |
268 tree arg1 = strip_float_extensions (TREE_OPERAND (expr, 1)); | |
269 | |
270 if (FLOAT_TYPE_P (TREE_TYPE (arg0)) | |
271 && FLOAT_TYPE_P (TREE_TYPE (arg1)) | |
272 && DECIMAL_FLOAT_TYPE_P (itype) == DECIMAL_FLOAT_TYPE_P (type)) | |
273 { | |
274 tree newtype = type; | |
275 | |
276 if (TYPE_MODE (TREE_TYPE (arg0)) == SDmode | |
277 || TYPE_MODE (TREE_TYPE (arg1)) == SDmode | |
278 || TYPE_MODE (type) == SDmode) | |
279 newtype = dfloat32_type_node; | |
280 if (TYPE_MODE (TREE_TYPE (arg0)) == DDmode | |
281 || TYPE_MODE (TREE_TYPE (arg1)) == DDmode | |
282 || TYPE_MODE (type) == DDmode) | |
283 newtype = dfloat64_type_node; | |
284 if (TYPE_MODE (TREE_TYPE (arg0)) == TDmode | |
285 || TYPE_MODE (TREE_TYPE (arg1)) == TDmode | |
286 || TYPE_MODE (type) == TDmode) | |
287 newtype = dfloat128_type_node; | |
288 if (newtype == dfloat32_type_node | |
289 || newtype == dfloat64_type_node | |
290 || newtype == dfloat128_type_node) | |
291 { | |
292 expr = build2 (TREE_CODE (expr), newtype, | |
293 fold (convert_to_real (newtype, arg0)), | |
294 fold (convert_to_real (newtype, arg1))); | |
295 if (newtype == type) | |
296 return expr; | |
297 break; | |
298 } | |
299 | |
300 if (TYPE_PRECISION (TREE_TYPE (arg0)) > TYPE_PRECISION (newtype)) | |
301 newtype = TREE_TYPE (arg0); | |
302 if (TYPE_PRECISION (TREE_TYPE (arg1)) > TYPE_PRECISION (newtype)) | |
303 newtype = TREE_TYPE (arg1); | |
304 /* Sometimes this transformation is safe (cannot | |
305 change results through affecting double rounding | |
306 cases) and sometimes it is not. If NEWTYPE is | |
307 wider than TYPE, e.g. (float)((long double)double | |
308 + (long double)double) converted to | |
309 (float)(double + double), the transformation is | |
310 unsafe regardless of the details of the types | |
311 involved; double rounding can arise if the result | |
312 of NEWTYPE arithmetic is a NEWTYPE value half way | |
313 between two representable TYPE values but the | |
314 exact value is sufficiently different (in the | |
315 right direction) for this difference to be | |
316 visible in ITYPE arithmetic. If NEWTYPE is the | |
317 same as TYPE, however, the transformation may be | |
318 safe depending on the types involved: it is safe | |
319 if the ITYPE has strictly more than twice as many | |
320 mantissa bits as TYPE, can represent infinities | |
321 and NaNs if the TYPE can, and has sufficient | |
322 exponent range for the product or ratio of two | |
323 values representable in the TYPE to be within the | |
324 range of normal values of ITYPE. */ | |
325 if (TYPE_PRECISION (newtype) < TYPE_PRECISION (itype) | |
326 && (flag_unsafe_math_optimizations | |
327 || (TYPE_PRECISION (newtype) == TYPE_PRECISION (type) | |
328 && real_can_shorten_arithmetic (TYPE_MODE (itype), | |
329 TYPE_MODE (type))))) | |
330 { | |
331 expr = build2 (TREE_CODE (expr), newtype, | |
332 fold (convert_to_real (newtype, arg0)), | |
333 fold (convert_to_real (newtype, arg1))); | |
334 if (newtype == type) | |
335 return expr; | |
336 } | |
337 } | |
338 } | |
339 break; | |
340 default: | |
341 break; | |
342 } | |
343 | |
344 switch (TREE_CODE (TREE_TYPE (expr))) | |
345 { | |
346 case REAL_TYPE: | |
347 /* Ignore the conversion if we don't need to store intermediate | |
348 results and neither type is a decimal float. */ | |
349 return build1 ((flag_float_store | |
350 || DECIMAL_FLOAT_TYPE_P (type) | |
351 || DECIMAL_FLOAT_TYPE_P (itype)) | |
352 ? CONVERT_EXPR : NOP_EXPR, type, expr); | |
353 | |
354 case INTEGER_TYPE: | |
355 case ENUMERAL_TYPE: | |
356 case BOOLEAN_TYPE: | |
357 return build1 (FLOAT_EXPR, type, expr); | |
358 | |
359 case FIXED_POINT_TYPE: | |
360 return build1 (FIXED_CONVERT_EXPR, type, expr); | |
361 | |
362 case COMPLEX_TYPE: | |
363 return convert (type, | |
364 fold_build1 (REALPART_EXPR, | |
365 TREE_TYPE (TREE_TYPE (expr)), expr)); | |
366 | |
367 case POINTER_TYPE: | |
368 case REFERENCE_TYPE: | |
369 error ("pointer value used where a floating point value was expected"); | |
370 return convert_to_real (type, integer_zero_node); | |
371 | |
372 default: | |
373 error ("aggregate value used where a float was expected"); | |
374 return convert_to_real (type, integer_zero_node); | |
375 } | |
376 } | |
377 | |
378 /* Convert EXPR to some integer (or enum) type TYPE. | |
379 | |
380 EXPR must be pointer, integer, discrete (enum, char, or bool), float, | |
381 fixed-point or vector; in other cases error is called. | |
382 | |
383 The result of this is always supposed to be a newly created tree node | |
384 not in use in any existing structure. */ | |
385 | |
386 tree | |
387 convert_to_integer (tree type, tree expr) | |
388 { | |
389 enum tree_code ex_form = TREE_CODE (expr); | |
390 tree intype = TREE_TYPE (expr); | |
391 unsigned int inprec = TYPE_PRECISION (intype); | |
392 unsigned int outprec = TYPE_PRECISION (type); | |
393 | |
394 /* An INTEGER_TYPE cannot be incomplete, but an ENUMERAL_TYPE can | |
395 be. Consider `enum E = { a, b = (enum E) 3 };'. */ | |
396 if (!COMPLETE_TYPE_P (type)) | |
397 { | |
398 error ("conversion to incomplete type"); | |
399 return error_mark_node; | |
400 } | |
401 | |
402 /* Convert e.g. (long)round(d) -> lround(d). */ | |
403 /* If we're converting to char, we may encounter differing behavior | |
404 between converting from double->char vs double->long->char. | |
405 We're in "undefined" territory but we prefer to be conservative, | |
406 so only proceed in "unsafe" math mode. */ | |
407 if (optimize | |
408 && (flag_unsafe_math_optimizations | |
409 || (long_integer_type_node | |
410 && outprec >= TYPE_PRECISION (long_integer_type_node)))) | |
411 { | |
412 tree s_expr = strip_float_extensions (expr); | |
413 tree s_intype = TREE_TYPE (s_expr); | |
414 const enum built_in_function fcode = builtin_mathfn_code (s_expr); | |
415 tree fn = 0; | |
416 | |
417 switch (fcode) | |
418 { | |
419 CASE_FLT_FN (BUILT_IN_CEIL): | |
420 /* Only convert in ISO C99 mode. */ | |
421 if (!TARGET_C99_FUNCTIONS) | |
422 break; | |
423 if (outprec < TYPE_PRECISION (long_integer_type_node) | |
424 || (outprec == TYPE_PRECISION (long_integer_type_node) | |
425 && !TYPE_UNSIGNED (type))) | |
426 fn = mathfn_built_in (s_intype, BUILT_IN_LCEIL); | |
427 else if (outprec == TYPE_PRECISION (long_long_integer_type_node) | |
428 && !TYPE_UNSIGNED (type)) | |
429 fn = mathfn_built_in (s_intype, BUILT_IN_LLCEIL); | |
430 break; | |
431 | |
432 CASE_FLT_FN (BUILT_IN_FLOOR): | |
433 /* Only convert in ISO C99 mode. */ | |
434 if (!TARGET_C99_FUNCTIONS) | |
435 break; | |
436 if (outprec < TYPE_PRECISION (long_integer_type_node) | |
437 || (outprec == TYPE_PRECISION (long_integer_type_node) | |
438 && !TYPE_UNSIGNED (type))) | |
439 fn = mathfn_built_in (s_intype, BUILT_IN_LFLOOR); | |
440 else if (outprec == TYPE_PRECISION (long_long_integer_type_node) | |
441 && !TYPE_UNSIGNED (type)) | |
442 fn = mathfn_built_in (s_intype, BUILT_IN_LLFLOOR); | |
443 break; | |
444 | |
445 CASE_FLT_FN (BUILT_IN_ROUND): | |
446 if (outprec < TYPE_PRECISION (long_integer_type_node) | |
447 || (outprec == TYPE_PRECISION (long_integer_type_node) | |
448 && !TYPE_UNSIGNED (type))) | |
449 fn = mathfn_built_in (s_intype, BUILT_IN_LROUND); | |
450 else if (outprec == TYPE_PRECISION (long_long_integer_type_node) | |
451 && !TYPE_UNSIGNED (type)) | |
452 fn = mathfn_built_in (s_intype, BUILT_IN_LLROUND); | |
453 break; | |
454 | |
455 CASE_FLT_FN (BUILT_IN_NEARBYINT): | |
456 /* Only convert nearbyint* if we can ignore math exceptions. */ | |
457 if (flag_trapping_math) | |
458 break; | |
459 /* ... Fall through ... */ | |
460 CASE_FLT_FN (BUILT_IN_RINT): | |
461 if (outprec < TYPE_PRECISION (long_integer_type_node) | |
462 || (outprec == TYPE_PRECISION (long_integer_type_node) | |
463 && !TYPE_UNSIGNED (type))) | |
464 fn = mathfn_built_in (s_intype, BUILT_IN_LRINT); | |
465 else if (outprec == TYPE_PRECISION (long_long_integer_type_node) | |
466 && !TYPE_UNSIGNED (type)) | |
467 fn = mathfn_built_in (s_intype, BUILT_IN_LLRINT); | |
468 break; | |
469 | |
470 CASE_FLT_FN (BUILT_IN_TRUNC): | |
471 return convert_to_integer (type, CALL_EXPR_ARG (s_expr, 0)); | |
472 | |
473 default: | |
474 break; | |
475 } | |
476 | |
477 if (fn) | |
478 { | |
479 tree newexpr = build_call_expr (fn, 1, CALL_EXPR_ARG (s_expr, 0)); | |
480 return convert_to_integer (type, newexpr); | |
481 } | |
482 } | |
483 | |
484 switch (TREE_CODE (intype)) | |
485 { | |
486 case POINTER_TYPE: | |
487 case REFERENCE_TYPE: | |
488 if (integer_zerop (expr)) | |
489 return build_int_cst (type, 0); | |
490 | |
491 /* Convert to an unsigned integer of the correct width first, | |
492 and from there widen/truncate to the required type. */ | |
493 expr = fold_build1 (CONVERT_EXPR, | |
494 lang_hooks.types.type_for_size (POINTER_SIZE, 0), | |
495 expr); | |
496 return fold_convert (type, expr); | |
497 | |
498 case INTEGER_TYPE: | |
499 case ENUMERAL_TYPE: | |
500 case BOOLEAN_TYPE: | |
501 case OFFSET_TYPE: | |
502 /* If this is a logical operation, which just returns 0 or 1, we can | |
503 change the type of the expression. */ | |
504 | |
505 if (TREE_CODE_CLASS (ex_form) == tcc_comparison) | |
506 { | |
507 expr = copy_node (expr); | |
508 TREE_TYPE (expr) = type; | |
509 return expr; | |
510 } | |
511 | |
512 /* If we are widening the type, put in an explicit conversion. | |
513 Similarly if we are not changing the width. After this, we know | |
514 we are truncating EXPR. */ | |
515 | |
516 else if (outprec >= inprec) | |
517 { | |
518 enum tree_code code; | |
519 tree tem; | |
520 | |
521 /* If the precision of the EXPR's type is K bits and the | |
522 destination mode has more bits, and the sign is changing, | |
523 it is not safe to use a NOP_EXPR. For example, suppose | |
524 that EXPR's type is a 3-bit unsigned integer type, the | |
525 TYPE is a 3-bit signed integer type, and the machine mode | |
526 for the types is 8-bit QImode. In that case, the | |
527 conversion necessitates an explicit sign-extension. In | |
528 the signed-to-unsigned case the high-order bits have to | |
529 be cleared. */ | |
530 if (TYPE_UNSIGNED (type) != TYPE_UNSIGNED (TREE_TYPE (expr)) | |
531 && (TYPE_PRECISION (TREE_TYPE (expr)) | |
532 != GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (expr))))) | |
533 code = CONVERT_EXPR; | |
534 else | |
535 code = NOP_EXPR; | |
536 | |
537 tem = fold_unary (code, type, expr); | |
538 if (tem) | |
539 return tem; | |
540 | |
541 tem = build1 (code, type, expr); | |
542 TREE_NO_WARNING (tem) = 1; | |
543 return tem; | |
544 } | |
545 | |
546 /* If TYPE is an enumeral type or a type with a precision less | |
547 than the number of bits in its mode, do the conversion to the | |
548 type corresponding to its mode, then do a nop conversion | |
549 to TYPE. */ | |
550 else if (TREE_CODE (type) == ENUMERAL_TYPE | |
551 || outprec != GET_MODE_BITSIZE (TYPE_MODE (type))) | |
552 return build1 (NOP_EXPR, type, | |
553 convert (lang_hooks.types.type_for_mode | |
554 (TYPE_MODE (type), TYPE_UNSIGNED (type)), | |
555 expr)); | |
556 | |
557 /* Here detect when we can distribute the truncation down past some | |
558 arithmetic. For example, if adding two longs and converting to an | |
559 int, we can equally well convert both to ints and then add. | |
560 For the operations handled here, such truncation distribution | |
561 is always safe. | |
562 It is desirable in these cases: | |
563 1) when truncating down to full-word from a larger size | |
564 2) when truncating takes no work. | |
565 3) when at least one operand of the arithmetic has been extended | |
566 (as by C's default conversions). In this case we need two conversions | |
567 if we do the arithmetic as already requested, so we might as well | |
568 truncate both and then combine. Perhaps that way we need only one. | |
569 | |
570 Note that in general we cannot do the arithmetic in a type | |
571 shorter than the desired result of conversion, even if the operands | |
572 are both extended from a shorter type, because they might overflow | |
573 if combined in that type. The exceptions to this--the times when | |
574 two narrow values can be combined in their narrow type even to | |
575 make a wider result--are handled by "shorten" in build_binary_op. */ | |
576 | |
577 switch (ex_form) | |
578 { | |
579 case RSHIFT_EXPR: | |
580 /* We can pass truncation down through right shifting | |
581 when the shift count is a nonpositive constant. */ | |
582 if (TREE_CODE (TREE_OPERAND (expr, 1)) == INTEGER_CST | |
583 && tree_int_cst_sgn (TREE_OPERAND (expr, 1)) <= 0) | |
584 goto trunc1; | |
585 break; | |
586 | |
587 case LSHIFT_EXPR: | |
588 /* We can pass truncation down through left shifting | |
589 when the shift count is a nonnegative constant and | |
590 the target type is unsigned. */ | |
591 if (TREE_CODE (TREE_OPERAND (expr, 1)) == INTEGER_CST | |
592 && tree_int_cst_sgn (TREE_OPERAND (expr, 1)) >= 0 | |
593 && TYPE_UNSIGNED (type) | |
594 && TREE_CODE (TYPE_SIZE (type)) == INTEGER_CST) | |
595 { | |
596 /* If shift count is less than the width of the truncated type, | |
597 really shift. */ | |
598 if (tree_int_cst_lt (TREE_OPERAND (expr, 1), TYPE_SIZE (type))) | |
599 /* In this case, shifting is like multiplication. */ | |
600 goto trunc1; | |
601 else | |
602 { | |
603 /* If it is >= that width, result is zero. | |
604 Handling this with trunc1 would give the wrong result: | |
605 (int) ((long long) a << 32) is well defined (as 0) | |
606 but (int) a << 32 is undefined and would get a | |
607 warning. */ | |
608 | |
609 tree t = build_int_cst (type, 0); | |
610 | |
611 /* If the original expression had side-effects, we must | |
612 preserve it. */ | |
613 if (TREE_SIDE_EFFECTS (expr)) | |
614 return build2 (COMPOUND_EXPR, type, expr, t); | |
615 else | |
616 return t; | |
617 } | |
618 } | |
619 break; | |
620 | |
621 case MAX_EXPR: | |
622 case MIN_EXPR: | |
623 case MULT_EXPR: | |
624 { | |
625 tree arg0 = get_unwidened (TREE_OPERAND (expr, 0), type); | |
626 tree arg1 = get_unwidened (TREE_OPERAND (expr, 1), type); | |
627 | |
628 /* Don't distribute unless the output precision is at least as big | |
629 as the actual inputs. Otherwise, the comparison of the | |
630 truncated values will be wrong. */ | |
631 if (outprec >= TYPE_PRECISION (TREE_TYPE (arg0)) | |
632 && outprec >= TYPE_PRECISION (TREE_TYPE (arg1)) | |
633 /* If signedness of arg0 and arg1 don't match, | |
634 we can't necessarily find a type to compare them in. */ | |
635 && (TYPE_UNSIGNED (TREE_TYPE (arg0)) | |
636 == TYPE_UNSIGNED (TREE_TYPE (arg1)))) | |
637 goto trunc1; | |
638 break; | |
639 } | |
640 | |
641 case PLUS_EXPR: | |
642 case MINUS_EXPR: | |
643 case BIT_AND_EXPR: | |
644 case BIT_IOR_EXPR: | |
645 case BIT_XOR_EXPR: | |
646 trunc1: | |
647 { | |
648 tree arg0 = get_unwidened (TREE_OPERAND (expr, 0), type); | |
649 tree arg1 = get_unwidened (TREE_OPERAND (expr, 1), type); | |
650 | |
651 if (outprec >= BITS_PER_WORD | |
652 || TRULY_NOOP_TRUNCATION (outprec, inprec) | |
653 || inprec > TYPE_PRECISION (TREE_TYPE (arg0)) | |
654 || inprec > TYPE_PRECISION (TREE_TYPE (arg1))) | |
655 { | |
656 /* Do the arithmetic in type TYPEX, | |
657 then convert result to TYPE. */ | |
658 tree typex = type; | |
659 | |
660 /* Can't do arithmetic in enumeral types | |
661 so use an integer type that will hold the values. */ | |
662 if (TREE_CODE (typex) == ENUMERAL_TYPE) | |
663 typex = lang_hooks.types.type_for_size | |
664 (TYPE_PRECISION (typex), TYPE_UNSIGNED (typex)); | |
665 | |
666 /* But now perhaps TYPEX is as wide as INPREC. | |
667 In that case, do nothing special here. | |
668 (Otherwise would recurse infinitely in convert. */ | |
669 if (TYPE_PRECISION (typex) != inprec) | |
670 { | |
671 /* Don't do unsigned arithmetic where signed was wanted, | |
672 or vice versa. | |
673 Exception: if both of the original operands were | |
674 unsigned then we can safely do the work as unsigned. | |
675 Exception: shift operations take their type solely | |
676 from the first argument. | |
677 Exception: the LSHIFT_EXPR case above requires that | |
678 we perform this operation unsigned lest we produce | |
679 signed-overflow undefinedness. | |
680 And we may need to do it as unsigned | |
681 if we truncate to the original size. */ | |
682 if (TYPE_UNSIGNED (TREE_TYPE (expr)) | |
683 || (TYPE_UNSIGNED (TREE_TYPE (arg0)) | |
684 && (TYPE_UNSIGNED (TREE_TYPE (arg1)) | |
685 || ex_form == LSHIFT_EXPR | |
686 || ex_form == RSHIFT_EXPR | |
687 || ex_form == LROTATE_EXPR | |
688 || ex_form == RROTATE_EXPR)) | |
689 || ex_form == LSHIFT_EXPR | |
690 /* If we have !flag_wrapv, and either ARG0 or | |
691 ARG1 is of a signed type, we have to do | |
692 PLUS_EXPR or MINUS_EXPR in an unsigned | |
693 type. Otherwise, we would introduce | |
694 signed-overflow undefinedness. */ | |
695 || ((!TYPE_OVERFLOW_WRAPS (TREE_TYPE (arg0)) | |
696 || !TYPE_OVERFLOW_WRAPS (TREE_TYPE (arg1))) | |
697 && (ex_form == PLUS_EXPR | |
698 || ex_form == MINUS_EXPR))) | |
699 typex = unsigned_type_for (typex); | |
700 else | |
701 typex = signed_type_for (typex); | |
702 return convert (type, | |
703 fold_build2 (ex_form, typex, | |
704 convert (typex, arg0), | |
705 convert (typex, arg1))); | |
706 } | |
707 } | |
708 } | |
709 break; | |
710 | |
711 case NEGATE_EXPR: | |
712 case BIT_NOT_EXPR: | |
713 /* This is not correct for ABS_EXPR, | |
714 since we must test the sign before truncation. */ | |
715 { | |
716 tree typex; | |
717 | |
718 /* Don't do unsigned arithmetic where signed was wanted, | |
719 or vice versa. */ | |
720 if (TYPE_UNSIGNED (TREE_TYPE (expr))) | |
721 typex = unsigned_type_for (type); | |
722 else | |
723 typex = signed_type_for (type); | |
724 return convert (type, | |
725 fold_build1 (ex_form, typex, | |
726 convert (typex, | |
727 TREE_OPERAND (expr, 0)))); | |
728 } | |
729 | |
730 case NOP_EXPR: | |
731 /* Don't introduce a | |
732 "can't convert between vector values of different size" error. */ | |
733 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (expr, 0))) == VECTOR_TYPE | |
734 && (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (TREE_OPERAND (expr, 0)))) | |
735 != GET_MODE_SIZE (TYPE_MODE (type)))) | |
736 break; | |
737 /* If truncating after truncating, might as well do all at once. | |
738 If truncating after extending, we may get rid of wasted work. */ | |
739 return convert (type, get_unwidened (TREE_OPERAND (expr, 0), type)); | |
740 | |
741 case COND_EXPR: | |
742 /* It is sometimes worthwhile to push the narrowing down through | |
19
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743 the conditional and never loses. A COND_EXPR may have a throw |
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744 as one operand, which then has void type. Just leave void |
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745 operands as they are. */ |
0 | 746 return fold_build3 (COND_EXPR, type, TREE_OPERAND (expr, 0), |
19
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747 VOID_TYPE_P (TREE_TYPE (TREE_OPERAND (expr, 1))) |
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748 ? TREE_OPERAND (expr, 1) |
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749 : convert (type, TREE_OPERAND (expr, 1)), |
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750 VOID_TYPE_P (TREE_TYPE (TREE_OPERAND (expr, 2))) |
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751 ? TREE_OPERAND (expr, 2) |
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752 : convert (type, TREE_OPERAND (expr, 2))); |
0 | 753 |
754 default: | |
755 break; | |
756 } | |
757 | |
758 return build1 (CONVERT_EXPR, type, expr); | |
759 | |
760 case REAL_TYPE: | |
761 return build1 (FIX_TRUNC_EXPR, type, expr); | |
762 | |
763 case FIXED_POINT_TYPE: | |
764 return build1 (FIXED_CONVERT_EXPR, type, expr); | |
765 | |
766 case COMPLEX_TYPE: | |
767 return convert (type, | |
768 fold_build1 (REALPART_EXPR, | |
769 TREE_TYPE (TREE_TYPE (expr)), expr)); | |
770 | |
771 case VECTOR_TYPE: | |
772 if (!tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (TREE_TYPE (expr)))) | |
773 { | |
774 error ("can't convert between vector values of different size"); | |
775 return error_mark_node; | |
776 } | |
777 return build1 (VIEW_CONVERT_EXPR, type, expr); | |
778 | |
779 default: | |
780 error ("aggregate value used where an integer was expected"); | |
781 return convert (type, integer_zero_node); | |
782 } | |
783 } | |
784 | |
785 /* Convert EXPR to the complex type TYPE in the usual ways. */ | |
786 | |
787 tree | |
788 convert_to_complex (tree type, tree expr) | |
789 { | |
790 tree subtype = TREE_TYPE (type); | |
791 | |
792 switch (TREE_CODE (TREE_TYPE (expr))) | |
793 { | |
794 case REAL_TYPE: | |
795 case FIXED_POINT_TYPE: | |
796 case INTEGER_TYPE: | |
797 case ENUMERAL_TYPE: | |
798 case BOOLEAN_TYPE: | |
799 return build2 (COMPLEX_EXPR, type, convert (subtype, expr), | |
800 convert (subtype, integer_zero_node)); | |
801 | |
802 case COMPLEX_TYPE: | |
803 { | |
804 tree elt_type = TREE_TYPE (TREE_TYPE (expr)); | |
805 | |
806 if (TYPE_MAIN_VARIANT (elt_type) == TYPE_MAIN_VARIANT (subtype)) | |
807 return expr; | |
808 else if (TREE_CODE (expr) == COMPLEX_EXPR) | |
809 return fold_build2 (COMPLEX_EXPR, type, | |
810 convert (subtype, TREE_OPERAND (expr, 0)), | |
811 convert (subtype, TREE_OPERAND (expr, 1))); | |
812 else | |
813 { | |
814 expr = save_expr (expr); | |
815 return | |
816 fold_build2 (COMPLEX_EXPR, type, | |
817 convert (subtype, | |
818 fold_build1 (REALPART_EXPR, | |
819 TREE_TYPE (TREE_TYPE (expr)), | |
820 expr)), | |
821 convert (subtype, | |
822 fold_build1 (IMAGPART_EXPR, | |
823 TREE_TYPE (TREE_TYPE (expr)), | |
824 expr))); | |
825 } | |
826 } | |
827 | |
828 case POINTER_TYPE: | |
829 case REFERENCE_TYPE: | |
830 error ("pointer value used where a complex was expected"); | |
831 return convert_to_complex (type, integer_zero_node); | |
832 | |
833 default: | |
834 error ("aggregate value used where a complex was expected"); | |
835 return convert_to_complex (type, integer_zero_node); | |
836 } | |
837 } | |
838 | |
839 /* Convert EXPR to the vector type TYPE in the usual ways. */ | |
840 | |
841 tree | |
842 convert_to_vector (tree type, tree expr) | |
843 { | |
844 switch (TREE_CODE (TREE_TYPE (expr))) | |
845 { | |
846 case INTEGER_TYPE: | |
847 case VECTOR_TYPE: | |
848 if (!tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (TREE_TYPE (expr)))) | |
849 { | |
850 error ("can't convert between vector values of different size"); | |
851 return error_mark_node; | |
852 } | |
853 return build1 (VIEW_CONVERT_EXPR, type, expr); | |
854 | |
855 default: | |
856 error ("can't convert value to a vector"); | |
857 return error_mark_node; | |
858 } | |
859 } | |
860 | |
861 /* Convert EXPR to some fixed-point type TYPE. | |
862 | |
863 EXPR must be fixed-point, float, integer, or enumeral; | |
864 in other cases error is called. */ | |
865 | |
866 tree | |
867 convert_to_fixed (tree type, tree expr) | |
868 { | |
869 if (integer_zerop (expr)) | |
870 { | |
871 tree fixed_zero_node = build_fixed (type, FCONST0 (TYPE_MODE (type))); | |
872 return fixed_zero_node; | |
873 } | |
874 else if (integer_onep (expr) && ALL_SCALAR_ACCUM_MODE_P (TYPE_MODE (type))) | |
875 { | |
876 tree fixed_one_node = build_fixed (type, FCONST1 (TYPE_MODE (type))); | |
877 return fixed_one_node; | |
878 } | |
879 | |
880 switch (TREE_CODE (TREE_TYPE (expr))) | |
881 { | |
882 case FIXED_POINT_TYPE: | |
883 case INTEGER_TYPE: | |
884 case ENUMERAL_TYPE: | |
885 case BOOLEAN_TYPE: | |
886 case REAL_TYPE: | |
887 return build1 (FIXED_CONVERT_EXPR, type, expr); | |
888 | |
889 case COMPLEX_TYPE: | |
890 return convert (type, | |
891 fold_build1 (REALPART_EXPR, | |
892 TREE_TYPE (TREE_TYPE (expr)), expr)); | |
893 | |
894 default: | |
895 error ("aggregate value used where a fixed-point was expected"); | |
896 return error_mark_node; | |
897 } | |
898 } |