52bfa921dc3c19e4719b84d50917551bc7625d8f
[mesa.git] / src / mesa / drivers / dri / i965 / brw_fs_copy_propagation.cpp
1 /*
2 * Copyright © 2012 Intel Corporation
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice (including the next
12 * paragraph) shall be included in all copies or substantial portions of the
13 * Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
21 * IN THE SOFTWARE.
22 */
23
24 /** @file brw_fs_copy_propagation.cpp
25 *
26 * Support for global copy propagation in two passes: A local pass that does
27 * intra-block copy (and constant) propagation, and a global pass that uses
28 * dataflow analysis on the copies available at the end of each block to re-do
29 * local copy propagation with more copies available.
30 *
31 * See Muchnick's Advanced Compiler Design and Implementation, section
32 * 12.5 (p356).
33 */
34
35 #define ACP_HASH_SIZE 16
36
37 #include "util/bitset.h"
38 #include "brw_fs.h"
39 #include "brw_cfg.h"
40
41 namespace { /* avoid conflict with opt_copy_propagation_elements */
42 struct acp_entry : public exec_node {
43 fs_reg dst;
44 fs_reg src;
45 uint8_t regs_written;
46 enum opcode opcode;
47 bool saturate;
48 };
49
50 struct block_data {
51 /**
52 * Which entries in the fs_copy_prop_dataflow acp table are live at the
53 * start of this block. This is the useful output of the analysis, since
54 * it lets us plug those into the local copy propagation on the second
55 * pass.
56 */
57 BITSET_WORD *livein;
58
59 /**
60 * Which entries in the fs_copy_prop_dataflow acp table are live at the end
61 * of this block. This is done in initial setup from the per-block acps
62 * returned by the first local copy prop pass.
63 */
64 BITSET_WORD *liveout;
65
66 /**
67 * Which entries in the fs_copy_prop_dataflow acp table are generated by
68 * instructions in this block which reach the end of the block without
69 * being killed.
70 */
71 BITSET_WORD *copy;
72
73 /**
74 * Which entries in the fs_copy_prop_dataflow acp table are killed over the
75 * course of this block.
76 */
77 BITSET_WORD *kill;
78 };
79
80 class fs_copy_prop_dataflow
81 {
82 public:
83 fs_copy_prop_dataflow(void *mem_ctx, cfg_t *cfg,
84 exec_list *out_acp[ACP_HASH_SIZE]);
85
86 void setup_initial_values();
87 void run();
88
89 void dump_block_data() const;
90
91 void *mem_ctx;
92 cfg_t *cfg;
93
94 acp_entry **acp;
95 int num_acp;
96 int bitset_words;
97
98 struct block_data *bd;
99 };
100 } /* anonymous namespace */
101
102 fs_copy_prop_dataflow::fs_copy_prop_dataflow(void *mem_ctx, cfg_t *cfg,
103 exec_list *out_acp[ACP_HASH_SIZE])
104 : mem_ctx(mem_ctx), cfg(cfg)
105 {
106 bd = rzalloc_array(mem_ctx, struct block_data, cfg->num_blocks);
107
108 num_acp = 0;
109 foreach_block (block, cfg) {
110 for (int i = 0; i < ACP_HASH_SIZE; i++) {
111 num_acp += out_acp[block->num][i].length();
112 }
113 }
114
115 acp = rzalloc_array(mem_ctx, struct acp_entry *, num_acp);
116
117 bitset_words = BITSET_WORDS(num_acp);
118
119 int next_acp = 0;
120 foreach_block (block, cfg) {
121 bd[block->num].livein = rzalloc_array(bd, BITSET_WORD, bitset_words);
122 bd[block->num].liveout = rzalloc_array(bd, BITSET_WORD, bitset_words);
123 bd[block->num].copy = rzalloc_array(bd, BITSET_WORD, bitset_words);
124 bd[block->num].kill = rzalloc_array(bd, BITSET_WORD, bitset_words);
125
126 for (int i = 0; i < ACP_HASH_SIZE; i++) {
127 foreach_in_list(acp_entry, entry, &out_acp[block->num][i]) {
128 acp[next_acp] = entry;
129
130 /* opt_copy_propagate_local populates out_acp with copies created
131 * in a block which are still live at the end of the block. This
132 * is exactly what we want in the COPY set.
133 */
134 BITSET_SET(bd[block->num].copy, next_acp);
135
136 next_acp++;
137 }
138 }
139 }
140
141 assert(next_acp == num_acp);
142
143 setup_initial_values();
144 run();
145 }
146
147 /**
148 * Set up initial values for each of the data flow sets, prior to running
149 * the fixed-point algorithm.
150 */
151 void
152 fs_copy_prop_dataflow::setup_initial_values()
153 {
154 /* Initialize the COPY and KILL sets. */
155 foreach_block (block, cfg) {
156 foreach_inst_in_block(fs_inst, inst, block) {
157 if (inst->dst.file != GRF)
158 continue;
159
160 /* Mark ACP entries which are killed by this instruction. */
161 for (int i = 0; i < num_acp; i++) {
162 if (inst->overwrites_reg(acp[i]->dst) ||
163 inst->overwrites_reg(acp[i]->src)) {
164 BITSET_SET(bd[block->num].kill, i);
165 }
166 }
167 }
168 }
169
170 /* Populate the initial values for the livein and liveout sets. For the
171 * block at the start of the program, livein = 0 and liveout = copy.
172 * For the others, set liveout to 0 (the empty set) and livein to ~0
173 * (the universal set).
174 */
175 foreach_block (block, cfg) {
176 if (block->parents.is_empty()) {
177 for (int i = 0; i < bitset_words; i++) {
178 bd[block->num].livein[i] = 0u;
179 bd[block->num].liveout[i] = bd[block->num].copy[i];
180 }
181 } else {
182 for (int i = 0; i < bitset_words; i++) {
183 bd[block->num].liveout[i] = 0u;
184 bd[block->num].livein[i] = ~0u;
185 }
186 }
187 }
188 }
189
190 /**
191 * Walk the set of instructions in the block, marking which entries in the acp
192 * are killed by the block.
193 */
194 void
195 fs_copy_prop_dataflow::run()
196 {
197 bool progress;
198
199 do {
200 progress = false;
201
202 /* Update liveout for all blocks. */
203 foreach_block (block, cfg) {
204 if (block->parents.is_empty())
205 continue;
206
207 for (int i = 0; i < bitset_words; i++) {
208 const BITSET_WORD old_liveout = bd[block->num].liveout[i];
209
210 bd[block->num].liveout[i] =
211 bd[block->num].copy[i] | (bd[block->num].livein[i] &
212 ~bd[block->num].kill[i]);
213
214 if (old_liveout != bd[block->num].liveout[i])
215 progress = true;
216 }
217 }
218
219 /* Update livein for all blocks. If a copy is live out of all parent
220 * blocks, it's live coming in to this block.
221 */
222 foreach_block (block, cfg) {
223 if (block->parents.is_empty())
224 continue;
225
226 for (int i = 0; i < bitset_words; i++) {
227 const BITSET_WORD old_livein = bd[block->num].livein[i];
228
229 bd[block->num].livein[i] = ~0u;
230 foreach_list_typed(bblock_link, parent_link, link, &block->parents) {
231 bblock_t *parent = parent_link->block;
232 bd[block->num].livein[i] &= bd[parent->num].liveout[i];
233 }
234
235 if (old_livein != bd[block->num].livein[i])
236 progress = true;
237 }
238 }
239 } while (progress);
240 }
241
242 void
243 fs_copy_prop_dataflow::dump_block_data() const
244 {
245 foreach_block (block, cfg) {
246 fprintf(stderr, "Block %d [%d, %d] (parents ", block->num,
247 block->start_ip, block->end_ip);
248 foreach_list_typed(bblock_link, link, link, &block->parents) {
249 bblock_t *parent = link->block;
250 fprintf(stderr, "%d ", parent->num);
251 }
252 fprintf(stderr, "):\n");
253 fprintf(stderr, " livein = 0x");
254 for (int i = 0; i < bitset_words; i++)
255 fprintf(stderr, "%08x", bd[block->num].livein[i]);
256 fprintf(stderr, ", liveout = 0x");
257 for (int i = 0; i < bitset_words; i++)
258 fprintf(stderr, "%08x", bd[block->num].liveout[i]);
259 fprintf(stderr, ",\n copy = 0x");
260 for (int i = 0; i < bitset_words; i++)
261 fprintf(stderr, "%08x", bd[block->num].copy[i]);
262 fprintf(stderr, ", kill = 0x");
263 for (int i = 0; i < bitset_words; i++)
264 fprintf(stderr, "%08x", bd[block->num].kill[i]);
265 fprintf(stderr, "\n");
266 }
267 }
268
269 static bool
270 is_logic_op(enum opcode opcode)
271 {
272 return (opcode == BRW_OPCODE_AND ||
273 opcode == BRW_OPCODE_OR ||
274 opcode == BRW_OPCODE_XOR ||
275 opcode == BRW_OPCODE_NOT);
276 }
277
278 static bool
279 can_change_source_types(fs_inst *inst)
280 {
281 return !inst->src[0].abs && !inst->src[0].negate &&
282 (inst->opcode == BRW_OPCODE_MOV ||
283 (inst->opcode == BRW_OPCODE_SEL &&
284 inst->predicate != BRW_PREDICATE_NONE &&
285 !inst->src[1].abs && !inst->src[1].negate));
286 }
287
288 bool
289 fs_visitor::try_copy_propagate(fs_inst *inst, int arg, acp_entry *entry)
290 {
291 if (inst->src[arg].file != GRF)
292 return false;
293
294 if (entry->src.file == IMM)
295 return false;
296 assert(entry->src.file == GRF || entry->src.file == UNIFORM ||
297 entry->src.file == ATTR);
298
299 if (entry->opcode == SHADER_OPCODE_LOAD_PAYLOAD &&
300 inst->opcode == SHADER_OPCODE_LOAD_PAYLOAD)
301 return false;
302
303 assert(entry->dst.file == GRF);
304 if (inst->src[arg].reg != entry->dst.reg)
305 return false;
306
307 /* Bail if inst is reading a range that isn't contained in the range
308 * that entry is writing.
309 */
310 if (inst->src[arg].reg_offset < entry->dst.reg_offset ||
311 (inst->src[arg].reg_offset * 32 + inst->src[arg].subreg_offset +
312 inst->regs_read(arg) * inst->src[arg].stride * 32) >
313 (entry->dst.reg_offset + entry->regs_written) * 32)
314 return false;
315
316 /* we can't generally copy-propagate UD negations because we
317 * can end up accessing the resulting values as signed integers
318 * instead. See also resolve_ud_negate() and comment in
319 * fs_generator::generate_code.
320 */
321 if (entry->src.type == BRW_REGISTER_TYPE_UD &&
322 entry->src.negate)
323 return false;
324
325 bool has_source_modifiers = entry->src.abs || entry->src.negate;
326
327 if ((has_source_modifiers || entry->src.file == UNIFORM ||
328 !entry->src.is_contiguous()) &&
329 !inst->can_do_source_mods(devinfo))
330 return false;
331
332 if (has_source_modifiers &&
333 inst->opcode == SHADER_OPCODE_GEN4_SCRATCH_WRITE)
334 return false;
335
336 /* Bail if the result of composing both strides would exceed the
337 * hardware limit.
338 */
339 if (entry->src.stride * inst->src[arg].stride > 4)
340 return false;
341
342 /* Bail if the result of composing both strides cannot be expressed
343 * as another stride. This avoids, for example, trying to transform
344 * this:
345 *
346 * MOV (8) rX<1>UD rY<0;1,0>UD
347 * FOO (8) ... rX<8;8,1>UW
348 *
349 * into this:
350 *
351 * FOO (8) ... rY<0;1,0>UW
352 *
353 * Which would have different semantics.
354 */
355 if (entry->src.stride != 1 &&
356 (inst->src[arg].stride *
357 type_sz(inst->src[arg].type)) % type_sz(entry->src.type) != 0)
358 return false;
359
360 if (has_source_modifiers &&
361 entry->dst.type != inst->src[arg].type &&
362 !can_change_source_types(inst))
363 return false;
364
365 if (devinfo->gen >= 8 && (entry->src.negate || entry->src.abs) &&
366 is_logic_op(inst->opcode)) {
367 return false;
368 }
369
370 if (entry->saturate) {
371 switch(inst->opcode) {
372 case BRW_OPCODE_SEL:
373 if (inst->src[1].file != IMM ||
374 inst->src[1].fixed_hw_reg.dw1.f < 0.0 ||
375 inst->src[1].fixed_hw_reg.dw1.f > 1.0) {
376 return false;
377 }
378 break;
379 default:
380 return false;
381 }
382 }
383
384 inst->src[arg].file = entry->src.file;
385 inst->src[arg].reg = entry->src.reg;
386 inst->src[arg].stride *= entry->src.stride;
387 inst->saturate = inst->saturate || entry->saturate;
388
389 switch (entry->src.file) {
390 case UNIFORM:
391 assert(entry->src.width == 1);
392 case BAD_FILE:
393 case HW_REG:
394 inst->src[arg].width = entry->src.width;
395 inst->src[arg].reg_offset = entry->src.reg_offset;
396 inst->src[arg].subreg_offset = entry->src.subreg_offset;
397 break;
398 case ATTR:
399 case GRF:
400 {
401 assert(entry->src.width % inst->src[arg].width == 0);
402 /* In this case, we'll just leave the width alone. The source
403 * register could have different widths depending on how it is
404 * being used. For instance, if only half of the register was
405 * used then we want to preserve that and continue to only use
406 * half.
407 *
408 * Also, we have to deal with mapping parts of vgrfs to other
409 * parts of vgrfs so we have to do some reg_offset magic.
410 */
411
412 /* Compute the offset of inst->src[arg] relative to inst->dst */
413 assert(entry->dst.subreg_offset == 0);
414 int rel_offset = inst->src[arg].reg_offset - entry->dst.reg_offset;
415 int rel_suboffset = inst->src[arg].subreg_offset;
416
417 /* Compute the final register offset (in bytes) */
418 int offset = entry->src.reg_offset * 32 + entry->src.subreg_offset;
419 offset += rel_offset * 32 + rel_suboffset;
420 inst->src[arg].reg_offset = offset / 32;
421 inst->src[arg].subreg_offset = offset % 32;
422 }
423 break;
424 default:
425 unreachable("Invalid register file");
426 break;
427 }
428
429 if (has_source_modifiers) {
430 if (entry->dst.type != inst->src[arg].type) {
431 /* We are propagating source modifiers from a MOV with a different
432 * type. If we got here, then we can just change the source and
433 * destination types of the instruction and keep going.
434 */
435 assert(can_change_source_types(inst));
436 for (int i = 0; i < inst->sources; i++) {
437 inst->src[i].type = entry->dst.type;
438 }
439 inst->dst.type = entry->dst.type;
440 }
441
442 if (!inst->src[arg].abs) {
443 inst->src[arg].abs = entry->src.abs;
444 inst->src[arg].negate ^= entry->src.negate;
445 }
446 }
447
448 return true;
449 }
450
451
452 bool
453 fs_visitor::try_constant_propagate(fs_inst *inst, acp_entry *entry)
454 {
455 bool progress = false;
456
457 if (entry->src.file != IMM)
458 return false;
459 if (entry->saturate)
460 return false;
461
462 for (int i = inst->sources - 1; i >= 0; i--) {
463 if (inst->src[i].file != GRF)
464 continue;
465
466 assert(entry->dst.file == GRF);
467 if (inst->src[i].reg != entry->dst.reg)
468 continue;
469
470 /* Bail if inst is reading a range that isn't contained in the range
471 * that entry is writing.
472 */
473 if (inst->src[i].reg_offset < entry->dst.reg_offset ||
474 (inst->src[i].reg_offset * 32 + inst->src[i].subreg_offset +
475 inst->regs_read(i) * inst->src[i].stride * 32) >
476 (entry->dst.reg_offset + entry->regs_written) * 32)
477 continue;
478
479 fs_reg val = entry->src;
480 val.type = inst->src[i].type;
481
482 if (inst->src[i].abs) {
483 if ((devinfo->gen >= 8 && is_logic_op(inst->opcode)) ||
484 !brw_abs_immediate(val.type, &val.fixed_hw_reg)) {
485 continue;
486 }
487 }
488
489 if (inst->src[i].negate) {
490 if ((devinfo->gen >= 8 && is_logic_op(inst->opcode)) ||
491 !brw_negate_immediate(val.type, &val.fixed_hw_reg)) {
492 continue;
493 }
494 }
495
496 switch (inst->opcode) {
497 case BRW_OPCODE_MOV:
498 case SHADER_OPCODE_LOAD_PAYLOAD:
499 inst->src[i] = val;
500 progress = true;
501 break;
502
503 case SHADER_OPCODE_INT_QUOTIENT:
504 case SHADER_OPCODE_INT_REMAINDER:
505 /* FINISHME: Promote non-float constants and remove this. */
506 if (devinfo->gen < 8)
507 break;
508 /* fallthrough */
509 case SHADER_OPCODE_POW:
510 /* Allow constant propagation into src1 (except on Gen 6), and let
511 * constant combining promote the constant on Gen < 8.
512 *
513 * While Gen 6 MATH can take a scalar source, its source and
514 * destination offsets must be equal and we cannot ensure that.
515 */
516 if (devinfo->gen == 6)
517 break;
518 /* fallthrough */
519 case BRW_OPCODE_BFI1:
520 case BRW_OPCODE_ASR:
521 case BRW_OPCODE_SHL:
522 case BRW_OPCODE_SHR:
523 case BRW_OPCODE_SUBB:
524 if (i == 1) {
525 inst->src[i] = val;
526 progress = true;
527 }
528 break;
529
530 case BRW_OPCODE_MACH:
531 case BRW_OPCODE_MUL:
532 case BRW_OPCODE_ADD:
533 case BRW_OPCODE_OR:
534 case BRW_OPCODE_AND:
535 case BRW_OPCODE_XOR:
536 case BRW_OPCODE_ADDC:
537 if (i == 1) {
538 inst->src[i] = val;
539 progress = true;
540 } else if (i == 0 && inst->src[1].file != IMM) {
541 /* Fit this constant in by commuting the operands.
542 * Exception: we can't do this for 32-bit integer MUL/MACH
543 * because it's asymmetric.
544 */
545 if ((inst->opcode == BRW_OPCODE_MUL ||
546 inst->opcode == BRW_OPCODE_MACH) &&
547 (inst->src[1].type == BRW_REGISTER_TYPE_D ||
548 inst->src[1].type == BRW_REGISTER_TYPE_UD))
549 break;
550 inst->src[0] = inst->src[1];
551 inst->src[1] = val;
552 progress = true;
553 }
554 break;
555
556 case BRW_OPCODE_CMP:
557 case BRW_OPCODE_IF:
558 if (i == 1) {
559 inst->src[i] = val;
560 progress = true;
561 } else if (i == 0 && inst->src[1].file != IMM) {
562 enum brw_conditional_mod new_cmod;
563
564 new_cmod = brw_swap_cmod(inst->conditional_mod);
565 if (new_cmod != BRW_CONDITIONAL_NONE) {
566 /* Fit this constant in by swapping the operands and
567 * flipping the test
568 */
569 inst->src[0] = inst->src[1];
570 inst->src[1] = val;
571 inst->conditional_mod = new_cmod;
572 progress = true;
573 }
574 }
575 break;
576
577 case BRW_OPCODE_SEL:
578 if (i == 1) {
579 inst->src[i] = val;
580 progress = true;
581 } else if (i == 0 && inst->src[1].file != IMM) {
582 inst->src[0] = inst->src[1];
583 inst->src[1] = val;
584
585 /* If this was predicated, flipping operands means
586 * we also need to flip the predicate.
587 */
588 if (inst->conditional_mod == BRW_CONDITIONAL_NONE) {
589 inst->predicate_inverse =
590 !inst->predicate_inverse;
591 }
592 progress = true;
593 }
594 break;
595
596 case SHADER_OPCODE_RCP:
597 /* The hardware doesn't do math on immediate values
598 * (because why are you doing that, seriously?), but
599 * the correct answer is to just constant fold it
600 * anyway.
601 */
602 assert(i == 0);
603 if (inst->src[0].fixed_hw_reg.dw1.f != 0.0f) {
604 inst->opcode = BRW_OPCODE_MOV;
605 inst->src[0] = val;
606 inst->src[0].fixed_hw_reg.dw1.f = 1.0f / inst->src[0].fixed_hw_reg.dw1.f;
607 progress = true;
608 }
609 break;
610
611 case FS_OPCODE_UNIFORM_PULL_CONSTANT_LOAD:
612 case SHADER_OPCODE_BROADCAST:
613 inst->src[i] = val;
614 progress = true;
615 break;
616
617 case BRW_OPCODE_MAD:
618 case BRW_OPCODE_LRP:
619 inst->src[i] = val;
620 progress = true;
621 break;
622
623 default:
624 break;
625 }
626 }
627
628 return progress;
629 }
630
631 static bool
632 can_propagate_from(fs_inst *inst)
633 {
634 return (inst->opcode == BRW_OPCODE_MOV &&
635 inst->dst.file == GRF &&
636 ((inst->src[0].file == GRF &&
637 (inst->src[0].reg != inst->dst.reg ||
638 inst->src[0].reg_offset != inst->dst.reg_offset)) ||
639 inst->src[0].file == ATTR ||
640 inst->src[0].file == UNIFORM ||
641 inst->src[0].file == IMM) &&
642 inst->src[0].type == inst->dst.type &&
643 !inst->is_partial_write());
644 }
645
646 /* Walks a basic block and does copy propagation on it using the acp
647 * list.
648 */
649 bool
650 fs_visitor::opt_copy_propagate_local(void *copy_prop_ctx, bblock_t *block,
651 exec_list *acp)
652 {
653 bool progress = false;
654
655 foreach_inst_in_block(fs_inst, inst, block) {
656 /* Try propagating into this instruction. */
657 for (int i = 0; i < inst->sources; i++) {
658 if (inst->src[i].file != GRF)
659 continue;
660
661 foreach_in_list(acp_entry, entry, &acp[inst->src[i].reg % ACP_HASH_SIZE]) {
662 if (try_constant_propagate(inst, entry))
663 progress = true;
664
665 if (try_copy_propagate(inst, i, entry))
666 progress = true;
667 }
668 }
669
670 /* kill the destination from the ACP */
671 if (inst->dst.file == GRF) {
672 foreach_in_list_safe(acp_entry, entry, &acp[inst->dst.reg % ACP_HASH_SIZE]) {
673 if (inst->overwrites_reg(entry->dst)) {
674 entry->remove();
675 }
676 }
677
678 /* Oops, we only have the chaining hash based on the destination, not
679 * the source, so walk across the entire table.
680 */
681 for (int i = 0; i < ACP_HASH_SIZE; i++) {
682 foreach_in_list_safe(acp_entry, entry, &acp[i]) {
683 if (inst->overwrites_reg(entry->src))
684 entry->remove();
685 }
686 }
687 }
688
689 /* If this instruction's source could potentially be folded into the
690 * operand of another instruction, add it to the ACP.
691 */
692 if (can_propagate_from(inst)) {
693 acp_entry *entry = ralloc(copy_prop_ctx, acp_entry);
694 entry->dst = inst->dst;
695 entry->src = inst->src[0];
696 entry->regs_written = inst->regs_written;
697 entry->opcode = inst->opcode;
698 entry->saturate = inst->saturate;
699 acp[entry->dst.reg % ACP_HASH_SIZE].push_tail(entry);
700 } else if (inst->opcode == SHADER_OPCODE_LOAD_PAYLOAD &&
701 inst->dst.file == GRF) {
702 int offset = 0;
703 for (int i = 0; i < inst->sources; i++) {
704 int effective_width = i < inst->header_size ? 8 : inst->exec_size;
705 int regs_written = effective_width / 8;
706 if (inst->src[i].file == GRF) {
707 acp_entry *entry = ralloc(copy_prop_ctx, acp_entry);
708 entry->dst = inst->dst;
709 entry->dst.reg_offset = offset;
710 entry->dst.width = effective_width;
711 entry->src = inst->src[i];
712 entry->regs_written = regs_written;
713 entry->opcode = inst->opcode;
714 if (!entry->dst.equals(inst->src[i])) {
715 acp[entry->dst.reg % ACP_HASH_SIZE].push_tail(entry);
716 } else {
717 ralloc_free(entry);
718 }
719 }
720 offset += regs_written;
721 }
722 }
723 }
724
725 return progress;
726 }
727
728 bool
729 fs_visitor::opt_copy_propagate()
730 {
731 bool progress = false;
732 void *copy_prop_ctx = ralloc_context(NULL);
733 exec_list *out_acp[cfg->num_blocks];
734
735 for (int i = 0; i < cfg->num_blocks; i++)
736 out_acp[i] = new exec_list [ACP_HASH_SIZE];
737
738 /* First, walk through each block doing local copy propagation and getting
739 * the set of copies available at the end of the block.
740 */
741 foreach_block (block, cfg) {
742 progress = opt_copy_propagate_local(copy_prop_ctx, block,
743 out_acp[block->num]) || progress;
744 }
745
746 /* Do dataflow analysis for those available copies. */
747 fs_copy_prop_dataflow dataflow(copy_prop_ctx, cfg, out_acp);
748
749 /* Next, re-run local copy propagation, this time with the set of copies
750 * provided by the dataflow analysis available at the start of a block.
751 */
752 foreach_block (block, cfg) {
753 exec_list in_acp[ACP_HASH_SIZE];
754
755 for (int i = 0; i < dataflow.num_acp; i++) {
756 if (BITSET_TEST(dataflow.bd[block->num].livein, i)) {
757 struct acp_entry *entry = dataflow.acp[i];
758 in_acp[entry->dst.reg % ACP_HASH_SIZE].push_tail(entry);
759 }
760 }
761
762 progress = opt_copy_propagate_local(copy_prop_ctx, block, in_acp) || progress;
763 }
764
765 for (int i = 0; i < cfg->num_blocks; i++)
766 delete [] out_acp[i];
767 ralloc_free(copy_prop_ctx);
768
769 if (progress)
770 invalidate_live_intervals();
771
772 return progress;
773 }