1 | /* Convert tree expression to rtl instructions, for GNU compiler. |
2 | Copyright (C) 1988-2023 Free Software Foundation, Inc. |
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 "backend.h" |
24 | #include "target.h" |
25 | #include "rtl.h" |
26 | #include "tree.h" |
27 | #include "predict.h" |
28 | #include "memmodel.h" |
29 | #include "tm_p.h" |
30 | #include "optabs.h" |
31 | #include "emit-rtl.h" |
32 | #include "fold-const.h" |
33 | #include "stor-layout.h" |
34 | /* Include expr.h after insn-config.h so we get HAVE_conditional_move. */ |
35 | #include "dojump.h" |
36 | #include "explow.h" |
37 | #include "expr.h" |
38 | #include "langhooks.h" |
39 | |
40 | static bool prefer_and_bit_test (scalar_int_mode, int); |
41 | static void do_jump (tree, rtx_code_label *, rtx_code_label *, |
42 | profile_probability); |
43 | static void do_jump_by_parts_greater (scalar_int_mode, tree, tree, int, |
44 | rtx_code_label *, rtx_code_label *, |
45 | profile_probability); |
46 | static void do_jump_by_parts_equality (scalar_int_mode, tree, tree, |
47 | rtx_code_label *, rtx_code_label *, |
48 | profile_probability); |
49 | static void do_compare_and_jump (tree, tree, enum rtx_code, enum rtx_code, |
50 | rtx_code_label *, rtx_code_label *, |
51 | profile_probability); |
52 | |
53 | /* At the start of a function, record that we have no previously-pushed |
54 | arguments waiting to be popped. */ |
55 | |
56 | void |
57 | init_pending_stack_adjust (void) |
58 | { |
59 | pending_stack_adjust = 0; |
60 | } |
61 | |
62 | /* Discard any pending stack adjustment. This avoid relying on the |
63 | RTL optimizers to remove useless adjustments when we know the |
64 | stack pointer value is dead. */ |
65 | void |
66 | discard_pending_stack_adjust (void) |
67 | { |
68 | stack_pointer_delta -= pending_stack_adjust; |
69 | pending_stack_adjust = 0; |
70 | } |
71 | |
72 | /* When exiting from function, if safe, clear out any pending stack adjust |
73 | so the adjustment won't get done. |
74 | |
75 | Note, if the current function calls alloca, then it must have a |
76 | frame pointer regardless of the value of flag_omit_frame_pointer. */ |
77 | |
78 | void |
79 | clear_pending_stack_adjust (void) |
80 | { |
81 | if (optimize > 0 |
82 | && (! flag_omit_frame_pointer || cfun->calls_alloca) |
83 | && EXIT_IGNORE_STACK) |
84 | discard_pending_stack_adjust (); |
85 | } |
86 | |
87 | /* Pop any previously-pushed arguments that have not been popped yet. */ |
88 | |
89 | void |
90 | do_pending_stack_adjust (void) |
91 | { |
92 | if (inhibit_defer_pop == 0) |
93 | { |
94 | if (maybe_ne (pending_stack_adjust, b: 0)) |
95 | adjust_stack (gen_int_mode (pending_stack_adjust, Pmode)); |
96 | pending_stack_adjust = 0; |
97 | } |
98 | } |
99 | |
100 | /* Remember pending_stack_adjust/stack_pointer_delta. |
101 | To be used around code that may call do_pending_stack_adjust (), |
102 | but the generated code could be discarded e.g. using delete_insns_since. */ |
103 | |
104 | void |
105 | save_pending_stack_adjust (saved_pending_stack_adjust *save) |
106 | { |
107 | save->x_pending_stack_adjust = pending_stack_adjust; |
108 | save->x_stack_pointer_delta = stack_pointer_delta; |
109 | } |
110 | |
111 | /* Restore the saved pending_stack_adjust/stack_pointer_delta. */ |
112 | |
113 | void |
114 | restore_pending_stack_adjust (saved_pending_stack_adjust *save) |
115 | { |
116 | if (inhibit_defer_pop == 0) |
117 | { |
118 | pending_stack_adjust = save->x_pending_stack_adjust; |
119 | stack_pointer_delta = save->x_stack_pointer_delta; |
120 | } |
121 | } |
122 | |
123 | /* Used internally by prefer_and_bit_test. */ |
124 | |
125 | static GTY(()) rtx and_reg; |
126 | static GTY(()) rtx and_test; |
127 | static GTY(()) rtx shift_test; |
128 | |
129 | /* Compare the relative costs of "(X & (1 << BITNUM))" and "(X >> BITNUM) & 1", |
130 | where X is an arbitrary register of mode MODE. Return true if the former |
131 | is preferred. */ |
132 | |
133 | static bool |
134 | prefer_and_bit_test (scalar_int_mode mode, int bitnum) |
135 | { |
136 | bool speed_p; |
137 | wide_int mask = wi::set_bit_in_zero (bit: bitnum, precision: GET_MODE_PRECISION (mode)); |
138 | |
139 | if (and_test == 0) |
140 | { |
141 | /* Set up rtxes for the two variations. Use NULL as a placeholder |
142 | for the BITNUM-based constants. */ |
143 | and_reg = gen_rtx_REG (mode, LAST_VIRTUAL_REGISTER + 1); |
144 | and_test = gen_rtx_AND (mode, and_reg, NULL); |
145 | shift_test = gen_rtx_AND (mode, gen_rtx_ASHIFTRT (mode, and_reg, NULL), |
146 | const1_rtx); |
147 | } |
148 | else |
149 | { |
150 | /* Change the mode of the previously-created rtxes. */ |
151 | PUT_MODE (x: and_reg, mode); |
152 | PUT_MODE (x: and_test, mode); |
153 | PUT_MODE (x: shift_test, mode); |
154 | PUT_MODE (XEXP (shift_test, 0), mode); |
155 | } |
156 | |
157 | /* Fill in the integers. */ |
158 | XEXP (and_test, 1) = immed_wide_int_const (mask, mode); |
159 | XEXP (XEXP (shift_test, 0), 1) = GEN_INT (bitnum); |
160 | |
161 | speed_p = optimize_insn_for_speed_p (); |
162 | return (rtx_cost (and_test, mode, IF_THEN_ELSE, 0, speed_p) |
163 | <= rtx_cost (shift_test, mode, IF_THEN_ELSE, 0, speed_p)); |
164 | } |
165 | |
166 | /* Subroutine of do_jump, dealing with exploded comparisons of the type |
167 | OP0 CODE OP1 . IF_FALSE_LABEL and IF_TRUE_LABEL like in do_jump. |
168 | PROB is probability of jump to if_true_label. */ |
169 | |
170 | static void |
171 | do_jump_1 (enum tree_code code, tree op0, tree op1, |
172 | rtx_code_label *if_false_label, rtx_code_label *if_true_label, |
173 | profile_probability prob) |
174 | { |
175 | machine_mode mode; |
176 | rtx_code_label *drop_through_label = 0; |
177 | scalar_int_mode int_mode; |
178 | |
179 | switch (code) |
180 | { |
181 | case EQ_EXPR: |
182 | { |
183 | tree inner_type = TREE_TYPE (op0); |
184 | |
185 | gcc_assert (GET_MODE_CLASS (TYPE_MODE (inner_type)) |
186 | != MODE_COMPLEX_FLOAT); |
187 | gcc_assert (GET_MODE_CLASS (TYPE_MODE (inner_type)) |
188 | != MODE_COMPLEX_INT); |
189 | |
190 | if (integer_zerop (op1)) |
191 | do_jump (op0, if_true_label, if_false_label, |
192 | prob.invert ()); |
193 | else if (is_int_mode (TYPE_MODE (inner_type), int_mode: &int_mode) |
194 | && !can_compare_p (EQ, int_mode, ccp_jump)) |
195 | do_jump_by_parts_equality (int_mode, op0, op1, if_false_label, |
196 | if_true_label, prob); |
197 | else |
198 | do_compare_and_jump (op0, op1, EQ, EQ, if_false_label, if_true_label, |
199 | prob); |
200 | break; |
201 | } |
202 | |
203 | case NE_EXPR: |
204 | { |
205 | tree inner_type = TREE_TYPE (op0); |
206 | |
207 | gcc_assert (GET_MODE_CLASS (TYPE_MODE (inner_type)) |
208 | != MODE_COMPLEX_FLOAT); |
209 | gcc_assert (GET_MODE_CLASS (TYPE_MODE (inner_type)) |
210 | != MODE_COMPLEX_INT); |
211 | |
212 | if (integer_zerop (op1)) |
213 | do_jump (op0, if_false_label, if_true_label, prob); |
214 | else if (is_int_mode (TYPE_MODE (inner_type), int_mode: &int_mode) |
215 | && !can_compare_p (NE, int_mode, ccp_jump)) |
216 | do_jump_by_parts_equality (int_mode, op0, op1, if_true_label, |
217 | if_false_label, prob.invert ()); |
218 | else |
219 | do_compare_and_jump (op0, op1, NE, NE, if_false_label, if_true_label, |
220 | prob); |
221 | break; |
222 | } |
223 | |
224 | case LT_EXPR: |
225 | mode = TYPE_MODE (TREE_TYPE (op0)); |
226 | if (is_int_mode (mode, int_mode: &int_mode) |
227 | && ! can_compare_p (LT, int_mode, ccp_jump)) |
228 | do_jump_by_parts_greater (int_mode, op0, op1, 1, if_false_label, |
229 | if_true_label, prob); |
230 | else |
231 | do_compare_and_jump (op0, op1, LT, LTU, if_false_label, if_true_label, |
232 | prob); |
233 | break; |
234 | |
235 | case LE_EXPR: |
236 | mode = TYPE_MODE (TREE_TYPE (op0)); |
237 | if (is_int_mode (mode, int_mode: &int_mode) |
238 | && ! can_compare_p (LE, int_mode, ccp_jump)) |
239 | do_jump_by_parts_greater (int_mode, op0, op1, 0, if_true_label, |
240 | if_false_label, prob.invert ()); |
241 | else |
242 | do_compare_and_jump (op0, op1, LE, LEU, if_false_label, if_true_label, |
243 | prob); |
244 | break; |
245 | |
246 | case GT_EXPR: |
247 | mode = TYPE_MODE (TREE_TYPE (op0)); |
248 | if (is_int_mode (mode, int_mode: &int_mode) |
249 | && ! can_compare_p (GT, int_mode, ccp_jump)) |
250 | do_jump_by_parts_greater (int_mode, op0, op1, 0, if_false_label, |
251 | if_true_label, prob); |
252 | else |
253 | do_compare_and_jump (op0, op1, GT, GTU, if_false_label, if_true_label, |
254 | prob); |
255 | break; |
256 | |
257 | case GE_EXPR: |
258 | mode = TYPE_MODE (TREE_TYPE (op0)); |
259 | if (is_int_mode (mode, int_mode: &int_mode) |
260 | && ! can_compare_p (GE, int_mode, ccp_jump)) |
261 | do_jump_by_parts_greater (int_mode, op0, op1, 1, if_true_label, |
262 | if_false_label, prob.invert ()); |
263 | else |
264 | do_compare_and_jump (op0, op1, GE, GEU, if_false_label, if_true_label, |
265 | prob); |
266 | break; |
267 | |
268 | case ORDERED_EXPR: |
269 | do_compare_and_jump (op0, op1, ORDERED, ORDERED, |
270 | if_false_label, if_true_label, prob); |
271 | break; |
272 | |
273 | case UNORDERED_EXPR: |
274 | do_compare_and_jump (op0, op1, UNORDERED, UNORDERED, |
275 | if_false_label, if_true_label, prob); |
276 | break; |
277 | |
278 | case UNLT_EXPR: |
279 | do_compare_and_jump (op0, op1, UNLT, UNLT, if_false_label, if_true_label, |
280 | prob); |
281 | break; |
282 | |
283 | case UNLE_EXPR: |
284 | do_compare_and_jump (op0, op1, UNLE, UNLE, if_false_label, if_true_label, |
285 | prob); |
286 | break; |
287 | |
288 | case UNGT_EXPR: |
289 | do_compare_and_jump (op0, op1, UNGT, UNGT, if_false_label, if_true_label, |
290 | prob); |
291 | break; |
292 | |
293 | case UNGE_EXPR: |
294 | do_compare_and_jump (op0, op1, UNGE, UNGE, if_false_label, if_true_label, |
295 | prob); |
296 | break; |
297 | |
298 | case UNEQ_EXPR: |
299 | do_compare_and_jump (op0, op1, UNEQ, UNEQ, if_false_label, if_true_label, |
300 | prob); |
301 | break; |
302 | |
303 | case LTGT_EXPR: |
304 | do_compare_and_jump (op0, op1, LTGT, LTGT, if_false_label, if_true_label, |
305 | prob); |
306 | break; |
307 | |
308 | case TRUTH_ANDIF_EXPR: |
309 | { |
310 | /* Spread the probability that the expression is false evenly between |
311 | the two conditions. So the first condition is false half the total |
312 | probability of being false. The second condition is false the other |
313 | half of the total probability of being false, so its jump has a false |
314 | probability of half the total, relative to the probability we |
315 | reached it (i.e. the first condition was true). */ |
316 | profile_probability op0_prob = profile_probability::uninitialized (); |
317 | profile_probability op1_prob = profile_probability::uninitialized (); |
318 | if (prob.initialized_p ()) |
319 | { |
320 | op1_prob = prob.invert (); |
321 | op0_prob = op1_prob.split (cprob: profile_probability::even ()); |
322 | /* Get the probability that each jump below is true. */ |
323 | op0_prob = op0_prob.invert (); |
324 | op1_prob = op1_prob.invert (); |
325 | } |
326 | if (if_false_label == NULL) |
327 | { |
328 | drop_through_label = gen_label_rtx (); |
329 | do_jump (op0, drop_through_label, NULL, op0_prob); |
330 | do_jump (op1, NULL, if_true_label, op1_prob); |
331 | } |
332 | else |
333 | { |
334 | do_jump (op0, if_false_label, NULL, op0_prob); |
335 | do_jump (op1, if_false_label, if_true_label, op1_prob); |
336 | } |
337 | break; |
338 | } |
339 | |
340 | case TRUTH_ORIF_EXPR: |
341 | { |
342 | /* Spread the probability evenly between the two conditions. So |
343 | the first condition has half the total probability of being true. |
344 | The second condition has the other half of the total probability, |
345 | so its jump has a probability of half the total, relative to |
346 | the probability we reached it (i.e. the first condition was false). */ |
347 | profile_probability op0_prob = profile_probability::uninitialized (); |
348 | profile_probability op1_prob = profile_probability::uninitialized (); |
349 | if (prob.initialized_p ()) |
350 | { |
351 | op1_prob = prob; |
352 | op0_prob = op1_prob.split (cprob: profile_probability::even ()); |
353 | } |
354 | if (if_true_label == NULL) |
355 | { |
356 | drop_through_label = gen_label_rtx (); |
357 | do_jump (op0, NULL, drop_through_label, op0_prob); |
358 | do_jump (op1, if_false_label, NULL, op1_prob); |
359 | } |
360 | else |
361 | { |
362 | do_jump (op0, NULL, if_true_label, op0_prob); |
363 | do_jump (op1, if_false_label, if_true_label, op1_prob); |
364 | } |
365 | break; |
366 | } |
367 | |
368 | default: |
369 | gcc_unreachable (); |
370 | } |
371 | |
372 | if (drop_through_label) |
373 | { |
374 | do_pending_stack_adjust (); |
375 | emit_label (drop_through_label); |
376 | } |
377 | } |
378 | |
379 | /* Generate code to evaluate EXP and jump to IF_FALSE_LABEL if |
380 | the result is zero, or IF_TRUE_LABEL if the result is one. |
381 | Either of IF_FALSE_LABEL and IF_TRUE_LABEL may be zero, |
382 | meaning fall through in that case. |
383 | |
384 | do_jump always does any pending stack adjust except when it does not |
385 | actually perform a jump. An example where there is no jump |
386 | is when EXP is `(foo (), 0)' and IF_FALSE_LABEL is null. |
387 | |
388 | PROB is probability of jump to if_true_label. */ |
389 | |
390 | static void |
391 | do_jump (tree exp, rtx_code_label *if_false_label, |
392 | rtx_code_label *if_true_label, profile_probability prob) |
393 | { |
394 | enum tree_code code = TREE_CODE (exp); |
395 | rtx temp; |
396 | int i; |
397 | tree type; |
398 | scalar_int_mode mode; |
399 | rtx_code_label *drop_through_label = NULL; |
400 | |
401 | switch (code) |
402 | { |
403 | case ERROR_MARK: |
404 | break; |
405 | |
406 | case INTEGER_CST: |
407 | { |
408 | rtx_code_label *lab = integer_zerop (exp) ? if_false_label |
409 | : if_true_label; |
410 | if (lab) |
411 | emit_jump (lab); |
412 | break; |
413 | } |
414 | |
415 | #if 0 |
416 | /* This is not true with #pragma weak */ |
417 | case ADDR_EXPR: |
418 | /* The address of something can never be zero. */ |
419 | if (if_true_label) |
420 | emit_jump (if_true_label); |
421 | break; |
422 | #endif |
423 | |
424 | CASE_CONVERT: |
425 | if (TREE_CODE (TREE_OPERAND (exp, 0)) == COMPONENT_REF |
426 | || TREE_CODE (TREE_OPERAND (exp, 0)) == BIT_FIELD_REF |
427 | || TREE_CODE (TREE_OPERAND (exp, 0)) == ARRAY_REF |
428 | || TREE_CODE (TREE_OPERAND (exp, 0)) == ARRAY_RANGE_REF) |
429 | goto normal; |
430 | /* If we are narrowing the operand, we have to do the compare in the |
431 | narrower mode. */ |
432 | if ((TYPE_PRECISION (TREE_TYPE (exp)) |
433 | < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (exp, 0))))) |
434 | goto normal; |
435 | /* FALLTHRU */ |
436 | case NON_LVALUE_EXPR: |
437 | case ABS_EXPR: |
438 | case ABSU_EXPR: |
439 | case NEGATE_EXPR: |
440 | case LROTATE_EXPR: |
441 | case RROTATE_EXPR: |
442 | /* These cannot change zero->nonzero or vice versa. */ |
443 | do_jump (TREE_OPERAND (exp, 0), if_false_label, if_true_label, prob); |
444 | break; |
445 | |
446 | case TRUTH_NOT_EXPR: |
447 | do_jump (TREE_OPERAND (exp, 0), if_false_label: if_true_label, if_true_label: if_false_label, |
448 | prob: prob.invert ()); |
449 | break; |
450 | |
451 | case COND_EXPR: |
452 | { |
453 | rtx_code_label *label1 = gen_label_rtx (); |
454 | if (!if_true_label || !if_false_label) |
455 | { |
456 | drop_through_label = gen_label_rtx (); |
457 | if (!if_true_label) |
458 | if_true_label = drop_through_label; |
459 | if (!if_false_label) |
460 | if_false_label = drop_through_label; |
461 | } |
462 | |
463 | do_pending_stack_adjust (); |
464 | do_jump (TREE_OPERAND (exp, 0), if_false_label: label1, NULL, |
465 | prob: profile_probability::uninitialized ()); |
466 | do_jump (TREE_OPERAND (exp, 1), if_false_label, if_true_label, prob); |
467 | emit_label (label1); |
468 | do_jump (TREE_OPERAND (exp, 2), if_false_label, if_true_label, prob); |
469 | break; |
470 | } |
471 | |
472 | case COMPOUND_EXPR: |
473 | /* Lowered by gimplify.cc. */ |
474 | gcc_unreachable (); |
475 | |
476 | case MINUS_EXPR: |
477 | /* Nonzero iff operands of minus differ. */ |
478 | code = NE_EXPR; |
479 | |
480 | /* FALLTHRU */ |
481 | case EQ_EXPR: |
482 | case NE_EXPR: |
483 | case LT_EXPR: |
484 | case LE_EXPR: |
485 | case GT_EXPR: |
486 | case GE_EXPR: |
487 | case ORDERED_EXPR: |
488 | case UNORDERED_EXPR: |
489 | case UNLT_EXPR: |
490 | case UNLE_EXPR: |
491 | case UNGT_EXPR: |
492 | case UNGE_EXPR: |
493 | case UNEQ_EXPR: |
494 | case LTGT_EXPR: |
495 | case TRUTH_ANDIF_EXPR: |
496 | case TRUTH_ORIF_EXPR: |
497 | other_code: |
498 | do_jump_1 (code, TREE_OPERAND (exp, 0), TREE_OPERAND (exp, 1), |
499 | if_false_label, if_true_label, prob); |
500 | break; |
501 | |
502 | case BIT_AND_EXPR: |
503 | /* fold_single_bit_test() converts (X & (1 << C)) into (X >> C) & 1. |
504 | See if the former is preferred for jump tests and restore it |
505 | if so. */ |
506 | if (integer_onep (TREE_OPERAND (exp, 1))) |
507 | { |
508 | tree exp0 = TREE_OPERAND (exp, 0); |
509 | rtx_code_label *set_label, *clr_label; |
510 | profile_probability setclr_prob = prob; |
511 | |
512 | /* Strip narrowing integral type conversions. */ |
513 | while (CONVERT_EXPR_P (exp0) |
514 | && TREE_OPERAND (exp0, 0) != error_mark_node |
515 | && TYPE_PRECISION (TREE_TYPE (exp0)) |
516 | <= TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (exp0, 0)))) |
517 | exp0 = TREE_OPERAND (exp0, 0); |
518 | |
519 | /* "exp0 ^ 1" inverts the sense of the single bit test. */ |
520 | if (TREE_CODE (exp0) == BIT_XOR_EXPR |
521 | && integer_onep (TREE_OPERAND (exp0, 1))) |
522 | { |
523 | exp0 = TREE_OPERAND (exp0, 0); |
524 | clr_label = if_true_label; |
525 | set_label = if_false_label; |
526 | setclr_prob = prob.invert (); |
527 | } |
528 | else |
529 | { |
530 | clr_label = if_false_label; |
531 | set_label = if_true_label; |
532 | } |
533 | |
534 | if (TREE_CODE (exp0) == RSHIFT_EXPR) |
535 | { |
536 | tree arg = TREE_OPERAND (exp0, 0); |
537 | tree shift = TREE_OPERAND (exp0, 1); |
538 | tree argtype = TREE_TYPE (arg); |
539 | if (TREE_CODE (shift) == INTEGER_CST |
540 | && compare_tree_int (shift, 0) >= 0 |
541 | && compare_tree_int (shift, HOST_BITS_PER_WIDE_INT) < 0 |
542 | && prefer_and_bit_test (SCALAR_INT_TYPE_MODE (argtype), |
543 | TREE_INT_CST_LOW (shift))) |
544 | { |
545 | unsigned HOST_WIDE_INT mask |
546 | = HOST_WIDE_INT_1U << TREE_INT_CST_LOW (shift); |
547 | do_jump (exp: build2 (BIT_AND_EXPR, argtype, arg, |
548 | build_int_cstu (type: argtype, mask)), |
549 | if_false_label: clr_label, if_true_label: set_label, prob: setclr_prob); |
550 | break; |
551 | } |
552 | } |
553 | } |
554 | |
555 | /* If we are AND'ing with a small constant, do this comparison in the |
556 | smallest type that fits. If the machine doesn't have comparisons |
557 | that small, it will be converted back to the wider comparison. |
558 | This helps if we are testing the sign bit of a narrower object. |
559 | combine can't do this for us because it can't know whether a |
560 | ZERO_EXTRACT or a compare in a smaller mode exists, but we do. */ |
561 | |
562 | if (! SLOW_BYTE_ACCESS |
563 | && TREE_CODE (TREE_OPERAND (exp, 1)) == INTEGER_CST |
564 | && TYPE_PRECISION (TREE_TYPE (exp)) <= HOST_BITS_PER_WIDE_INT |
565 | && (i = tree_floor_log2 (TREE_OPERAND (exp, 1))) >= 0 |
566 | && int_mode_for_size (size: i + 1, limit: 0).exists (mode: &mode) |
567 | && (type = lang_hooks.types.type_for_mode (mode, 1)) != 0 |
568 | && TYPE_PRECISION (type) < TYPE_PRECISION (TREE_TYPE (exp)) |
569 | && have_insn_for (COMPARE, TYPE_MODE (type))) |
570 | { |
571 | do_jump (fold_convert (type, exp), if_false_label, if_true_label, |
572 | prob); |
573 | break; |
574 | } |
575 | |
576 | if (TYPE_PRECISION (TREE_TYPE (exp)) > 1 |
577 | || TREE_CODE (TREE_OPERAND (exp, 1)) == INTEGER_CST) |
578 | goto normal; |
579 | |
580 | /* Boolean comparisons can be compiled as TRUTH_AND_EXPR. */ |
581 | /* FALLTHRU */ |
582 | |
583 | case TRUTH_AND_EXPR: |
584 | /* High branch cost, expand as the bitwise AND of the conditions. |
585 | Do the same if the RHS has side effects, because we're effectively |
586 | turning a TRUTH_AND_EXPR into a TRUTH_ANDIF_EXPR. */ |
587 | if (BRANCH_COST (optimize_insn_for_speed_p (), |
588 | false) >= 4 |
589 | || TREE_SIDE_EFFECTS (TREE_OPERAND (exp, 1))) |
590 | goto normal; |
591 | code = TRUTH_ANDIF_EXPR; |
592 | goto other_code; |
593 | |
594 | case BIT_IOR_EXPR: |
595 | case TRUTH_OR_EXPR: |
596 | /* High branch cost, expand as the bitwise OR of the conditions. |
597 | Do the same if the RHS has side effects, because we're effectively |
598 | turning a TRUTH_OR_EXPR into a TRUTH_ORIF_EXPR. */ |
599 | if (BRANCH_COST (optimize_insn_for_speed_p (), false) >= 4 |
600 | || TREE_SIDE_EFFECTS (TREE_OPERAND (exp, 1))) |
601 | goto normal; |
602 | code = TRUTH_ORIF_EXPR; |
603 | goto other_code; |
604 | |
605 | /* Fall through and generate the normal code. */ |
606 | default: |
607 | normal: |
608 | temp = expand_normal (exp); |
609 | do_pending_stack_adjust (); |
610 | /* The RTL optimizers prefer comparisons against pseudos. */ |
611 | if (GET_CODE (temp) == SUBREG) |
612 | { |
613 | /* Compare promoted variables in their promoted mode. */ |
614 | if (SUBREG_PROMOTED_VAR_P (temp) |
615 | && REG_P (XEXP (temp, 0))) |
616 | temp = XEXP (temp, 0); |
617 | else |
618 | temp = copy_to_reg (temp); |
619 | } |
620 | do_compare_rtx_and_jump (temp, CONST0_RTX (GET_MODE (temp)), |
621 | NE, TYPE_UNSIGNED (TREE_TYPE (exp)), |
622 | exp, GET_MODE (temp), NULL_RTX, |
623 | if_false_label, if_true_label, prob); |
624 | } |
625 | |
626 | if (drop_through_label) |
627 | { |
628 | do_pending_stack_adjust (); |
629 | emit_label (drop_through_label); |
630 | } |
631 | } |
632 | |
633 | /* Compare OP0 with OP1, word at a time, in mode MODE. |
634 | UNSIGNEDP says to do unsigned comparison. |
635 | Jump to IF_TRUE_LABEL if OP0 is greater, IF_FALSE_LABEL otherwise. */ |
636 | |
637 | static void |
638 | do_jump_by_parts_greater_rtx (scalar_int_mode mode, int unsignedp, rtx op0, |
639 | rtx op1, rtx_code_label *if_false_label, |
640 | rtx_code_label *if_true_label, |
641 | profile_probability prob) |
642 | { |
643 | int nwords = (GET_MODE_SIZE (mode) / UNITS_PER_WORD); |
644 | rtx_code_label *drop_through_label = 0; |
645 | bool drop_through_if_true = false, drop_through_if_false = false; |
646 | enum rtx_code code = GT; |
647 | int i; |
648 | |
649 | if (! if_true_label || ! if_false_label) |
650 | drop_through_label = gen_label_rtx (); |
651 | if (! if_true_label) |
652 | { |
653 | if_true_label = drop_through_label; |
654 | drop_through_if_true = true; |
655 | } |
656 | if (! if_false_label) |
657 | { |
658 | if_false_label = drop_through_label; |
659 | drop_through_if_false = true; |
660 | } |
661 | |
662 | /* Deal with the special case 0 > x: only one comparison is necessary and |
663 | we reverse it to avoid jumping to the drop-through label. */ |
664 | if (op0 == const0_rtx && drop_through_if_true && !drop_through_if_false) |
665 | { |
666 | code = LE; |
667 | if_true_label = if_false_label; |
668 | if_false_label = drop_through_label; |
669 | prob = prob.invert (); |
670 | } |
671 | |
672 | /* Compare a word at a time, high order first. */ |
673 | for (i = 0; i < nwords; i++) |
674 | { |
675 | rtx op0_word, op1_word; |
676 | |
677 | if (WORDS_BIG_ENDIAN) |
678 | { |
679 | op0_word = operand_subword_force (op0, i, mode); |
680 | op1_word = operand_subword_force (op1, i, mode); |
681 | } |
682 | else |
683 | { |
684 | op0_word = operand_subword_force (op0, nwords - 1 - i, mode); |
685 | op1_word = operand_subword_force (op1, nwords - 1 - i, mode); |
686 | } |
687 | |
688 | /* All but high-order word must be compared as unsigned. */ |
689 | do_compare_rtx_and_jump (op0_word, op1_word, code, (unsignedp || i > 0), |
690 | NULL, word_mode, NULL_RTX, NULL, if_true_label, |
691 | prob); |
692 | |
693 | /* Emit only one comparison for 0. Do not emit the last cond jump. */ |
694 | if (op0 == const0_rtx || i == nwords - 1) |
695 | break; |
696 | |
697 | /* Consider lower words only if these are equal. */ |
698 | do_compare_rtx_and_jump (op0_word, op1_word, NE, unsignedp, NULL, |
699 | word_mode, NULL_RTX, NULL, if_false_label, |
700 | prob.invert ()); |
701 | } |
702 | |
703 | if (!drop_through_if_false) |
704 | emit_jump (if_false_label); |
705 | if (drop_through_label) |
706 | emit_label (drop_through_label); |
707 | } |
708 | |
709 | /* Given a comparison expression EXP for values too wide to be compared |
710 | with one insn, test the comparison and jump to the appropriate label. |
711 | The code of EXP is ignored; we always test GT if SWAP is 0, |
712 | and LT if SWAP is 1. MODE is the mode of the two operands. */ |
713 | |
714 | static void |
715 | do_jump_by_parts_greater (scalar_int_mode mode, tree treeop0, tree treeop1, |
716 | int swap, rtx_code_label *if_false_label, |
717 | rtx_code_label *if_true_label, |
718 | profile_probability prob) |
719 | { |
720 | rtx op0 = expand_normal (exp: swap ? treeop1 : treeop0); |
721 | rtx op1 = expand_normal (exp: swap ? treeop0 : treeop1); |
722 | int unsignedp = TYPE_UNSIGNED (TREE_TYPE (treeop0)); |
723 | |
724 | do_jump_by_parts_greater_rtx (mode, unsignedp, op0, op1, if_false_label, |
725 | if_true_label, prob); |
726 | } |
727 | |
728 | /* Jump according to whether OP0 is 0. We assume that OP0 has an integer |
729 | mode, MODE, that is too wide for the available compare insns. Either |
730 | Either (but not both) of IF_TRUE_LABEL and IF_FALSE_LABEL may be NULL |
731 | to indicate drop through. */ |
732 | |
733 | static void |
734 | do_jump_by_parts_zero_rtx (scalar_int_mode mode, rtx op0, |
735 | rtx_code_label *if_false_label, |
736 | rtx_code_label *if_true_label, |
737 | profile_probability prob) |
738 | { |
739 | int nwords = GET_MODE_SIZE (mode) / UNITS_PER_WORD; |
740 | rtx part; |
741 | int i; |
742 | rtx_code_label *drop_through_label = NULL; |
743 | |
744 | /* The fastest way of doing this comparison on almost any machine is to |
745 | "or" all the words and compare the result. If all have to be loaded |
746 | from memory and this is a very wide item, it's possible this may |
747 | be slower, but that's highly unlikely. */ |
748 | |
749 | part = gen_reg_rtx (word_mode); |
750 | emit_move_insn (part, operand_subword_force (op0, 0, mode)); |
751 | for (i = 1; i < nwords && part != 0; i++) |
752 | part = expand_binop (word_mode, ior_optab, part, |
753 | operand_subword_force (op0, i, mode), |
754 | part, 1, OPTAB_WIDEN); |
755 | |
756 | if (part != 0) |
757 | { |
758 | do_compare_rtx_and_jump (part, const0_rtx, EQ, 1, NULL, word_mode, |
759 | NULL_RTX, if_false_label, if_true_label, prob); |
760 | return; |
761 | } |
762 | |
763 | /* If we couldn't do the "or" simply, do this with a series of compares. */ |
764 | if (! if_false_label) |
765 | if_false_label = drop_through_label = gen_label_rtx (); |
766 | |
767 | for (i = 0; i < nwords; i++) |
768 | do_compare_rtx_and_jump (operand_subword_force (op0, i, mode), |
769 | const0_rtx, EQ, 1, NULL, word_mode, NULL_RTX, |
770 | if_false_label, NULL, prob); |
771 | |
772 | if (if_true_label) |
773 | emit_jump (if_true_label); |
774 | |
775 | if (drop_through_label) |
776 | emit_label (drop_through_label); |
777 | } |
778 | |
779 | /* Test for the equality of two RTX expressions OP0 and OP1 in mode MODE, |
780 | where MODE is an integer mode too wide to be compared with one insn. |
781 | Either (but not both) of IF_TRUE_LABEL and IF_FALSE_LABEL may be NULL_RTX |
782 | to indicate drop through. */ |
783 | |
784 | static void |
785 | do_jump_by_parts_equality_rtx (scalar_int_mode mode, rtx op0, rtx op1, |
786 | rtx_code_label *if_false_label, |
787 | rtx_code_label *if_true_label, |
788 | profile_probability prob) |
789 | { |
790 | int nwords = (GET_MODE_SIZE (mode) / UNITS_PER_WORD); |
791 | rtx_code_label *drop_through_label = NULL; |
792 | int i; |
793 | |
794 | if (op1 == const0_rtx) |
795 | { |
796 | do_jump_by_parts_zero_rtx (mode, op0, if_false_label, if_true_label, |
797 | prob); |
798 | return; |
799 | } |
800 | else if (op0 == const0_rtx) |
801 | { |
802 | do_jump_by_parts_zero_rtx (mode, op0: op1, if_false_label, if_true_label, |
803 | prob); |
804 | return; |
805 | } |
806 | |
807 | if (! if_false_label) |
808 | drop_through_label = if_false_label = gen_label_rtx (); |
809 | |
810 | for (i = 0; i < nwords; i++) |
811 | do_compare_rtx_and_jump (operand_subword_force (op0, i, mode), |
812 | operand_subword_force (op1, i, mode), |
813 | EQ, 0, NULL, word_mode, NULL_RTX, |
814 | if_false_label, NULL, prob); |
815 | |
816 | if (if_true_label) |
817 | emit_jump (if_true_label); |
818 | if (drop_through_label) |
819 | emit_label (drop_through_label); |
820 | } |
821 | |
822 | /* Given an EQ_EXPR expression EXP for values too wide to be compared |
823 | with one insn, test the comparison and jump to the appropriate label. |
824 | MODE is the mode of the two operands. */ |
825 | |
826 | static void |
827 | do_jump_by_parts_equality (scalar_int_mode mode, tree treeop0, tree treeop1, |
828 | rtx_code_label *if_false_label, |
829 | rtx_code_label *if_true_label, |
830 | profile_probability prob) |
831 | { |
832 | rtx op0 = expand_normal (exp: treeop0); |
833 | rtx op1 = expand_normal (exp: treeop1); |
834 | do_jump_by_parts_equality_rtx (mode, op0, op1, if_false_label, |
835 | if_true_label, prob); |
836 | } |
837 | |
838 | /* Split a comparison into two others, the second of which has the other |
839 | "orderedness". The first is always ORDERED or UNORDERED if MODE |
840 | does not honor NaNs (which means that it can be skipped in that case; |
841 | see do_compare_rtx_and_jump). |
842 | |
843 | The two conditions are written in *CODE1 and *CODE2. Return true if |
844 | the conditions must be ANDed, false if they must be ORed. */ |
845 | |
846 | bool |
847 | split_comparison (enum rtx_code code, machine_mode mode, |
848 | enum rtx_code *code1, enum rtx_code *code2) |
849 | { |
850 | switch (code) |
851 | { |
852 | case LT: |
853 | *code1 = ORDERED; |
854 | *code2 = UNLT; |
855 | return true; |
856 | case LE: |
857 | *code1 = ORDERED; |
858 | *code2 = UNLE; |
859 | return true; |
860 | case GT: |
861 | *code1 = ORDERED; |
862 | *code2 = UNGT; |
863 | return true; |
864 | case GE: |
865 | *code1 = ORDERED; |
866 | *code2 = UNGE; |
867 | return true; |
868 | case EQ: |
869 | *code1 = ORDERED; |
870 | *code2 = UNEQ; |
871 | return true; |
872 | case NE: |
873 | *code1 = UNORDERED; |
874 | *code2 = LTGT; |
875 | return false; |
876 | case UNLT: |
877 | *code1 = UNORDERED; |
878 | *code2 = LT; |
879 | return false; |
880 | case UNLE: |
881 | *code1 = UNORDERED; |
882 | *code2 = LE; |
883 | return false; |
884 | case UNGT: |
885 | *code1 = UNORDERED; |
886 | *code2 = GT; |
887 | return false; |
888 | case UNGE: |
889 | *code1 = UNORDERED; |
890 | *code2 = GE; |
891 | return false; |
892 | case UNEQ: |
893 | *code1 = UNORDERED; |
894 | *code2 = EQ; |
895 | return false; |
896 | case LTGT: |
897 | /* Do not turn a trapping comparison into a non-trapping one. */ |
898 | if (HONOR_NANS (mode)) |
899 | { |
900 | *code1 = LT; |
901 | *code2 = GT; |
902 | return false; |
903 | } |
904 | else |
905 | { |
906 | *code1 = ORDERED; |
907 | *code2 = NE; |
908 | return true; |
909 | } |
910 | default: |
911 | gcc_unreachable (); |
912 | } |
913 | } |
914 | |
915 | /* Generate code to evaluate EXP and jump to LABEL if the value is nonzero. |
916 | PROB is probability of jump to LABEL. */ |
917 | |
918 | void |
919 | jumpif (tree exp, rtx_code_label *label, profile_probability prob) |
920 | { |
921 | do_jump (exp, NULL, if_true_label: label, prob); |
922 | } |
923 | |
924 | /* Similar to jumpif but dealing with exploded comparisons of the type |
925 | OP0 CODE OP1 . LABEL and PROB are like in jumpif. */ |
926 | |
927 | void |
928 | jumpif_1 (enum tree_code code, tree op0, tree op1, rtx_code_label *label, |
929 | profile_probability prob) |
930 | { |
931 | do_jump_1 (code, op0, op1, NULL, if_true_label: label, prob); |
932 | } |
933 | |
934 | /* Generate code to evaluate EXP and jump to LABEL if the value is zero. |
935 | PROB is probability of jump to LABEL. */ |
936 | |
937 | void |
938 | jumpifnot (tree exp, rtx_code_label *label, profile_probability prob) |
939 | { |
940 | do_jump (exp, if_false_label: label, NULL, prob: prob.invert ()); |
941 | } |
942 | |
943 | /* Similar to jumpifnot but dealing with exploded comparisons of the type |
944 | OP0 CODE OP1 . LABEL and PROB are like in jumpifnot. */ |
945 | |
946 | void |
947 | jumpifnot_1 (enum tree_code code, tree op0, tree op1, rtx_code_label *label, |
948 | profile_probability prob) |
949 | { |
950 | do_jump_1 (code, op0, op1, if_false_label: label, NULL, prob: prob.invert ()); |
951 | } |
952 | |
953 | /* Like do_compare_and_jump but expects the values to compare as two rtx's. |
954 | The decision as to signed or unsigned comparison must be made by the caller. |
955 | |
956 | If MODE is BLKmode, SIZE is an RTX giving the size of the objects being |
957 | compared. */ |
958 | |
959 | void |
960 | do_compare_rtx_and_jump (rtx op0, rtx op1, enum rtx_code code, int unsignedp, |
961 | machine_mode mode, rtx size, |
962 | rtx_code_label *if_false_label, |
963 | rtx_code_label *if_true_label, |
964 | profile_probability prob) |
965 | { |
966 | do_compare_rtx_and_jump (op0, op1, code, unsignedp, NULL, mode, size, |
967 | if_false_label, if_true_label, prob); |
968 | } |
969 | |
970 | /* Like do_compare_and_jump but expects the values to compare as two rtx's. |
971 | The decision as to signed or unsigned comparison must be made by the caller. |
972 | |
973 | If MODE is BLKmode, SIZE is an RTX giving the size of the objects being |
974 | compared. */ |
975 | |
976 | void |
977 | do_compare_rtx_and_jump (rtx op0, rtx op1, enum rtx_code code, int unsignedp, |
978 | tree val, machine_mode mode, rtx size, |
979 | rtx_code_label *if_false_label, |
980 | rtx_code_label *if_true_label, |
981 | profile_probability prob) |
982 | { |
983 | rtx tem; |
984 | rtx_code_label *dummy_label = NULL; |
985 | |
986 | /* Reverse the comparison if that is safe and we want to jump if it is |
987 | false. Also convert to the reverse comparison if the target can |
988 | implement it. */ |
989 | if ((! if_true_label |
990 | || ! can_compare_p (code, mode, ccp_jump)) |
991 | && (! FLOAT_MODE_P (mode) |
992 | || code == ORDERED || code == UNORDERED |
993 | || (! HONOR_NANS (mode) && (code == LTGT || code == UNEQ)) |
994 | || (! HONOR_SNANS (mode) && (code == EQ || code == NE)))) |
995 | { |
996 | enum rtx_code rcode; |
997 | if (FLOAT_MODE_P (mode)) |
998 | rcode = reverse_condition_maybe_unordered (code); |
999 | else |
1000 | rcode = reverse_condition (code); |
1001 | |
1002 | /* Canonicalize to UNORDERED for the libcall. */ |
1003 | if (can_compare_p (rcode, mode, ccp_jump) |
1004 | || (code == ORDERED && ! can_compare_p (ORDERED, mode, ccp_jump))) |
1005 | { |
1006 | std::swap (a&: if_true_label, b&: if_false_label); |
1007 | code = rcode; |
1008 | prob = prob.invert (); |
1009 | } |
1010 | } |
1011 | |
1012 | /* If one operand is constant, make it the second one. Only do this |
1013 | if the other operand is not constant as well. */ |
1014 | |
1015 | if (swap_commutative_operands_p (op0, op1)) |
1016 | { |
1017 | std::swap (a&: op0, b&: op1); |
1018 | code = swap_condition (code); |
1019 | } |
1020 | |
1021 | do_pending_stack_adjust (); |
1022 | |
1023 | code = unsignedp ? unsigned_condition (code) : code; |
1024 | if ((tem = simplify_relational_operation (code, mode, VOIDmode, |
1025 | op0, op1)) != 0) |
1026 | { |
1027 | if (CONSTANT_P (tem)) |
1028 | { |
1029 | rtx_code_label *label = (tem == const0_rtx |
1030 | || tem == CONST0_RTX (mode)) |
1031 | ? if_false_label : if_true_label; |
1032 | if (label) |
1033 | emit_jump (label); |
1034 | return; |
1035 | } |
1036 | |
1037 | code = GET_CODE (tem); |
1038 | mode = GET_MODE (tem); |
1039 | op0 = XEXP (tem, 0); |
1040 | op1 = XEXP (tem, 1); |
1041 | unsignedp = (code == GTU || code == LTU || code == GEU || code == LEU); |
1042 | } |
1043 | |
1044 | if (! if_true_label) |
1045 | dummy_label = if_true_label = gen_label_rtx (); |
1046 | |
1047 | scalar_int_mode int_mode; |
1048 | if (is_int_mode (mode, int_mode: &int_mode) |
1049 | && ! can_compare_p (code, int_mode, ccp_jump)) |
1050 | { |
1051 | switch (code) |
1052 | { |
1053 | case LTU: |
1054 | do_jump_by_parts_greater_rtx (mode: int_mode, unsignedp: 1, op0: op1, op1: op0, |
1055 | if_false_label, if_true_label, prob); |
1056 | break; |
1057 | |
1058 | case LEU: |
1059 | do_jump_by_parts_greater_rtx (mode: int_mode, unsignedp: 1, op0, op1, |
1060 | if_false_label: if_true_label, if_true_label: if_false_label, |
1061 | prob: prob.invert ()); |
1062 | break; |
1063 | |
1064 | case GTU: |
1065 | do_jump_by_parts_greater_rtx (mode: int_mode, unsignedp: 1, op0, op1, |
1066 | if_false_label, if_true_label, prob); |
1067 | break; |
1068 | |
1069 | case GEU: |
1070 | do_jump_by_parts_greater_rtx (mode: int_mode, unsignedp: 1, op0: op1, op1: op0, |
1071 | if_false_label: if_true_label, if_true_label: if_false_label, |
1072 | prob: prob.invert ()); |
1073 | break; |
1074 | |
1075 | case LT: |
1076 | do_jump_by_parts_greater_rtx (mode: int_mode, unsignedp: 0, op0: op1, op1: op0, |
1077 | if_false_label, if_true_label, prob); |
1078 | break; |
1079 | |
1080 | case LE: |
1081 | do_jump_by_parts_greater_rtx (mode: int_mode, unsignedp: 0, op0, op1, |
1082 | if_false_label: if_true_label, if_true_label: if_false_label, |
1083 | prob: prob.invert ()); |
1084 | break; |
1085 | |
1086 | case GT: |
1087 | do_jump_by_parts_greater_rtx (mode: int_mode, unsignedp: 0, op0, op1, |
1088 | if_false_label, if_true_label, prob); |
1089 | break; |
1090 | |
1091 | case GE: |
1092 | do_jump_by_parts_greater_rtx (mode: int_mode, unsignedp: 0, op0: op1, op1: op0, |
1093 | if_false_label: if_true_label, if_true_label: if_false_label, |
1094 | prob: prob.invert ()); |
1095 | break; |
1096 | |
1097 | case EQ: |
1098 | do_jump_by_parts_equality_rtx (mode: int_mode, op0, op1, if_false_label, |
1099 | if_true_label, prob); |
1100 | break; |
1101 | |
1102 | case NE: |
1103 | do_jump_by_parts_equality_rtx (mode: int_mode, op0, op1, if_false_label: if_true_label, |
1104 | if_true_label: if_false_label, |
1105 | prob: prob.invert ()); |
1106 | break; |
1107 | |
1108 | default: |
1109 | gcc_unreachable (); |
1110 | } |
1111 | } |
1112 | else |
1113 | { |
1114 | if (SCALAR_FLOAT_MODE_P (mode) |
1115 | && ! can_compare_p (code, mode, ccp_jump) |
1116 | && can_compare_p (swap_condition (code), mode, ccp_jump)) |
1117 | { |
1118 | code = swap_condition (code); |
1119 | std::swap (a&: op0, b&: op1); |
1120 | } |
1121 | else if (SCALAR_FLOAT_MODE_P (mode) |
1122 | && ! can_compare_p (code, mode, ccp_jump) |
1123 | /* Never split ORDERED and UNORDERED. |
1124 | These must be implemented. */ |
1125 | && (code != ORDERED && code != UNORDERED) |
1126 | /* Split a floating-point comparison if |
1127 | we can jump on other conditions... */ |
1128 | && (have_insn_for (COMPARE, mode) |
1129 | /* ... or if there is no libcall for it. */ |
1130 | || code_to_optab (code) == unknown_optab)) |
1131 | { |
1132 | enum rtx_code first_code, orig_code = code; |
1133 | bool and_them = split_comparison (code, mode, code1: &first_code, code2: &code); |
1134 | |
1135 | /* If there are no NaNs, the first comparison should always fall |
1136 | through. */ |
1137 | if (!HONOR_NANS (mode)) |
1138 | gcc_assert (first_code == (and_them ? ORDERED : UNORDERED)); |
1139 | |
1140 | else if ((orig_code == EQ || orig_code == NE) |
1141 | && rtx_equal_p (op0, op1)) |
1142 | /* Self-comparisons x == x or x != x can be optimized into |
1143 | just x ord x or x nord x. */ |
1144 | code = orig_code == EQ ? ORDERED : UNORDERED; |
1145 | |
1146 | else |
1147 | { |
1148 | profile_probability cprob |
1149 | = profile_probability::guessed_always (); |
1150 | if (first_code == UNORDERED) |
1151 | cprob /= 100; |
1152 | else if (first_code == ORDERED) |
1153 | cprob = cprob.apply_scale (num: 99, den: 100); |
1154 | else |
1155 | cprob = profile_probability::even (); |
1156 | /* For and_them we want to split: |
1157 | if (x) goto t; // prob; |
1158 | goto f; |
1159 | into |
1160 | if (a) ; else goto f; // first_prob for ; |
1161 | // 1 - first_prob for goto f; |
1162 | if (b) goto t; // adjusted prob; |
1163 | goto f; |
1164 | such that the overall probability of jumping to t |
1165 | remains the same. The and_them case should be |
1166 | probability-wise equivalent to the !and_them case with |
1167 | f and t swapped and also the conditions inverted, i.e. |
1168 | if (!a) goto f; |
1169 | if (!b) goto f; |
1170 | goto t; |
1171 | where the overall probability of jumping to f is |
1172 | 1 - prob (thus the first prob.invert () below). |
1173 | cprob.invert () is because the a condition is inverted, |
1174 | so if it was originally ORDERED, !a is UNORDERED and |
1175 | thus should be relative 1% rather than 99%. |
1176 | The invert () on assignment to first_prob is because |
1177 | first_prob represents the probability of fallthru, |
1178 | rather than goto f. And the last prob.invert () is |
1179 | because the adjusted prob represents the probability of |
1180 | jumping to t rather than to f. */ |
1181 | if (and_them) |
1182 | { |
1183 | rtx_code_label *dest_label; |
1184 | prob = prob.invert (); |
1185 | profile_probability first_prob |
1186 | = prob.split (cprob: cprob.invert ()).invert (); |
1187 | prob = prob.invert (); |
1188 | /* If we only jump if true, just bypass the second jump. */ |
1189 | if (! if_false_label) |
1190 | { |
1191 | if (! dummy_label) |
1192 | dummy_label = gen_label_rtx (); |
1193 | dest_label = dummy_label; |
1194 | } |
1195 | else |
1196 | dest_label = if_false_label; |
1197 | |
1198 | do_compare_rtx_and_jump (op0, op1, code: first_code, unsignedp, |
1199 | val, mode, size, if_false_label: dest_label, NULL, |
1200 | prob: first_prob); |
1201 | } |
1202 | /* For !and_them we want to split: |
1203 | if (x) goto t; // prob; |
1204 | goto f; |
1205 | into |
1206 | if (a) goto t; // first_prob; |
1207 | if (b) goto t; // adjusted prob; |
1208 | goto f; |
1209 | such that the overall probability of jumping to t |
1210 | remains the same and first_prob is prob * cprob. */ |
1211 | else |
1212 | { |
1213 | profile_probability first_prob = prob.split (cprob); |
1214 | do_compare_rtx_and_jump (op0, op1, code: first_code, unsignedp, |
1215 | val, mode, size, NULL, |
1216 | if_true_label, prob: first_prob); |
1217 | if (orig_code == NE && can_compare_p (UNEQ, mode, ccp_jump)) |
1218 | { |
1219 | /* x != y can be split into x unord y || x ltgt y |
1220 | or x unord y || !(x uneq y). The latter has the |
1221 | advantage that both comparisons are non-signalling and |
1222 | so there is a higher chance that the RTL optimizations |
1223 | merge the two comparisons into just one. */ |
1224 | code = UNEQ; |
1225 | prob = prob.invert (); |
1226 | if (! if_false_label) |
1227 | { |
1228 | if (! dummy_label) |
1229 | dummy_label = gen_label_rtx (); |
1230 | if_false_label = dummy_label; |
1231 | } |
1232 | std::swap (a&: if_false_label, b&: if_true_label); |
1233 | } |
1234 | } |
1235 | } |
1236 | } |
1237 | |
1238 | emit_cmp_and_jump_insns (op0, op1, code, size, mode, unsignedp, val, |
1239 | if_true_label, prob); |
1240 | } |
1241 | |
1242 | if (if_false_label) |
1243 | emit_jump (if_false_label); |
1244 | if (dummy_label) |
1245 | emit_label (dummy_label); |
1246 | } |
1247 | |
1248 | /* Generate code for a comparison expression EXP (including code to compute |
1249 | the values to be compared) and a conditional jump to IF_FALSE_LABEL and/or |
1250 | IF_TRUE_LABEL. One of the labels can be NULL_RTX, in which case the |
1251 | generated code will drop through. |
1252 | SIGNED_CODE should be the rtx operation for this comparison for |
1253 | signed data; UNSIGNED_CODE, likewise for use if data is unsigned. |
1254 | |
1255 | We force a stack adjustment unless there are currently |
1256 | things pushed on the stack that aren't yet used. */ |
1257 | |
1258 | static void |
1259 | do_compare_and_jump (tree treeop0, tree treeop1, enum rtx_code signed_code, |
1260 | enum rtx_code unsigned_code, |
1261 | rtx_code_label *if_false_label, |
1262 | rtx_code_label *if_true_label, profile_probability prob) |
1263 | { |
1264 | rtx op0, op1; |
1265 | tree type; |
1266 | machine_mode mode; |
1267 | int unsignedp; |
1268 | enum rtx_code code; |
1269 | |
1270 | /* Don't crash if the comparison was erroneous. */ |
1271 | op0 = expand_normal (exp: treeop0); |
1272 | if (TREE_CODE (treeop0) == ERROR_MARK) |
1273 | return; |
1274 | |
1275 | op1 = expand_normal (exp: treeop1); |
1276 | if (TREE_CODE (treeop1) == ERROR_MARK) |
1277 | return; |
1278 | |
1279 | type = TREE_TYPE (treeop0); |
1280 | if (TREE_CODE (treeop0) == INTEGER_CST |
1281 | && (TREE_CODE (treeop1) != INTEGER_CST |
1282 | || (GET_MODE_BITSIZE (SCALAR_INT_TYPE_MODE (type)) |
1283 | > GET_MODE_BITSIZE (SCALAR_INT_TYPE_MODE (TREE_TYPE (treeop1)))))) |
1284 | /* op0 might have been replaced by promoted constant, in which |
1285 | case the type of second argument should be used. */ |
1286 | type = TREE_TYPE (treeop1); |
1287 | mode = TYPE_MODE (type); |
1288 | unsignedp = TYPE_UNSIGNED (type); |
1289 | code = unsignedp ? unsigned_code : signed_code; |
1290 | |
1291 | /* If function pointers need to be "canonicalized" before they can |
1292 | be reliably compared, then canonicalize them. Canonicalize the |
1293 | expression when one of the operands is a function pointer. This |
1294 | handles the case where the other operand is a void pointer. See |
1295 | PR middle-end/17564. */ |
1296 | if (targetm.have_canonicalize_funcptr_for_compare () |
1297 | && ((POINTER_TYPE_P (TREE_TYPE (treeop0)) |
1298 | && FUNC_OR_METHOD_TYPE_P (TREE_TYPE (TREE_TYPE (treeop0)))) |
1299 | || (POINTER_TYPE_P (TREE_TYPE (treeop1)) |
1300 | && FUNC_OR_METHOD_TYPE_P (TREE_TYPE (TREE_TYPE (treeop1)))))) |
1301 | { |
1302 | rtx new_op0 = gen_reg_rtx (mode); |
1303 | rtx new_op1 = gen_reg_rtx (mode); |
1304 | |
1305 | emit_insn (targetm.gen_canonicalize_funcptr_for_compare (new_op0, op0)); |
1306 | op0 = new_op0; |
1307 | |
1308 | emit_insn (targetm.gen_canonicalize_funcptr_for_compare (new_op1, op1)); |
1309 | op1 = new_op1; |
1310 | } |
1311 | |
1312 | do_compare_rtx_and_jump (op0, op1, code, unsignedp, val: treeop0, mode, |
1313 | size: ((mode == BLKmode) |
1314 | ? expr_size (treeop0) : NULL_RTX), |
1315 | if_false_label, if_true_label, prob); |
1316 | } |
1317 | |
1318 | #include "gt-dojump.h" |
1319 | |