2 * Copyright © 2016 Intel Corporation
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:
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
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
25 #include "nir_builder.h"
26 #include "nir_deref.h"
28 #include "util/bitscan.h"
29 #include "util/u_dynarray.h"
32 * Variable-based copy propagation
34 * Normally, NIR trusts in SSA form for most of its copy-propagation needs.
35 * However, there are cases, especially when dealing with indirects, where SSA
36 * won't help you. This pass is for those times. Specifically, it handles
37 * the following things that the rest of NIR can't:
39 * 1) Copy-propagation on variables that have indirect access. This includes
40 * propagating from indirect stores into indirect loads.
42 * 2) Removal of redundant load_deref intrinsics. We can't trust regular CSE
43 * to do this because it isn't aware of variable writes that may alias the
44 * value and make the former load invalid.
46 * This pass uses an intermediate solution between being local / "per-block"
47 * and a complete data-flow analysis. It follows the control flow graph, and
48 * propagate the available copy information forward, invalidating data at each
51 * Removal of dead writes to variables is handled by another pass.
55 nir_variable_mode modes
;
57 /* Key is deref and value is the uintptr_t with the write mask. */
58 struct hash_table
*derefs
;
65 nir_deref_instr
*deref
;
75 struct copy_prop_var_state
{
76 nir_function_impl
*impl
;
81 /* Maps nodes to vars_written. Used to invalidate copy entries when
84 struct hash_table
*vars_written_map
;
90 value_equals_store_src(struct value
*value
, nir_intrinsic_instr
*intrin
)
92 assert(intrin
->intrinsic
== nir_intrinsic_store_deref
);
93 uintptr_t write_mask
= nir_intrinsic_write_mask(intrin
);
95 for (unsigned i
= 0; i
< intrin
->num_components
; i
++) {
96 if ((write_mask
& (1 << i
)) &&
97 value
->ssa
[i
] != intrin
->src
[1].ssa
)
104 static struct vars_written
*
105 create_vars_written(struct copy_prop_var_state
*state
)
107 struct vars_written
*written
=
108 linear_zalloc_child(state
->lin_ctx
, sizeof(struct vars_written
));
109 written
->derefs
= _mesa_hash_table_create(state
->mem_ctx
, _mesa_hash_pointer
,
110 _mesa_key_pointer_equal
);
115 gather_vars_written(struct copy_prop_var_state
*state
,
116 struct vars_written
*written
,
117 nir_cf_node
*cf_node
)
119 struct vars_written
*new_written
= NULL
;
121 switch (cf_node
->type
) {
122 case nir_cf_node_function
: {
123 nir_function_impl
*impl
= nir_cf_node_as_function(cf_node
);
124 foreach_list_typed_safe(nir_cf_node
, cf_node
, node
, &impl
->body
)
125 gather_vars_written(state
, NULL
, cf_node
);
129 case nir_cf_node_block
: {
133 nir_block
*block
= nir_cf_node_as_block(cf_node
);
134 nir_foreach_instr(instr
, block
) {
135 if (instr
->type
== nir_instr_type_call
) {
136 written
->modes
|= nir_var_shader_out
|
144 if (instr
->type
!= nir_instr_type_intrinsic
)
147 nir_intrinsic_instr
*intrin
= nir_instr_as_intrinsic(instr
);
148 switch (intrin
->intrinsic
) {
149 case nir_intrinsic_barrier
:
150 case nir_intrinsic_memory_barrier
:
151 written
->modes
|= nir_var_shader_out
|
156 case nir_intrinsic_emit_vertex
:
157 case nir_intrinsic_emit_vertex_with_counter
:
158 written
->modes
= nir_var_shader_out
;
161 case nir_intrinsic_store_deref
:
162 case nir_intrinsic_copy_deref
: {
163 /* Destination in _both_ store_deref and copy_deref is src[0]. */
164 nir_deref_instr
*dst
= nir_src_as_deref(intrin
->src
[0]);
166 uintptr_t mask
= intrin
->intrinsic
== nir_intrinsic_store_deref
?
167 nir_intrinsic_write_mask(intrin
) : (1 << glsl_get_vector_elements(dst
->type
)) - 1;
169 struct hash_entry
*ht_entry
= _mesa_hash_table_search(written
->derefs
, dst
);
171 ht_entry
->data
= (void *)(mask
| (uintptr_t)ht_entry
->data
);
173 _mesa_hash_table_insert(written
->derefs
, dst
, (void *)mask
);
186 case nir_cf_node_if
: {
187 nir_if
*if_stmt
= nir_cf_node_as_if(cf_node
);
189 new_written
= create_vars_written(state
);
191 foreach_list_typed_safe(nir_cf_node
, cf_node
, node
, &if_stmt
->then_list
)
192 gather_vars_written(state
, new_written
, cf_node
);
194 foreach_list_typed_safe(nir_cf_node
, cf_node
, node
, &if_stmt
->else_list
)
195 gather_vars_written(state
, new_written
, cf_node
);
200 case nir_cf_node_loop
: {
201 nir_loop
*loop
= nir_cf_node_as_loop(cf_node
);
203 new_written
= create_vars_written(state
);
205 foreach_list_typed_safe(nir_cf_node
, cf_node
, node
, &loop
->body
)
206 gather_vars_written(state
, new_written
, cf_node
);
212 unreachable("Invalid CF node type");
216 /* Merge new information to the parent control flow node. */
218 written
->modes
|= new_written
->modes
;
219 hash_table_foreach(new_written
->derefs
, new_entry
) {
220 struct hash_entry
*old_entry
=
221 _mesa_hash_table_search_pre_hashed(written
->derefs
, new_entry
->hash
,
224 nir_component_mask_t merged
= (uintptr_t) new_entry
->data
|
225 (uintptr_t) old_entry
->data
;
226 old_entry
->data
= (void *) ((uintptr_t) merged
);
228 _mesa_hash_table_insert_pre_hashed(written
->derefs
, new_entry
->hash
,
229 new_entry
->key
, new_entry
->data
);
233 _mesa_hash_table_insert(state
->vars_written_map
, cf_node
, new_written
);
237 static struct copy_entry
*
238 copy_entry_create(struct util_dynarray
*copies
,
239 nir_deref_instr
*dst_deref
)
241 struct copy_entry new_entry
= {
244 util_dynarray_append(copies
, struct copy_entry
, new_entry
);
245 return util_dynarray_top_ptr(copies
, struct copy_entry
);
248 /* Remove copy entry by swapping it with the last element and reducing the
249 * size. If used inside an iteration on copies, it must be a reverse
250 * (backwards) iteration. It is safe to use in those cases because the swap
251 * will not affect the rest of the iteration.
254 copy_entry_remove(struct util_dynarray
*copies
,
255 struct copy_entry
*entry
)
257 /* This also works when removing the last element since pop don't shrink
258 * the memory used by the array, so the swap is useless but not invalid.
260 *entry
= util_dynarray_pop(copies
, struct copy_entry
);
263 static struct copy_entry
*
264 lookup_entry_for_deref(struct util_dynarray
*copies
,
265 nir_deref_instr
*deref
,
266 nir_deref_compare_result allowed_comparisons
)
268 util_dynarray_foreach(copies
, struct copy_entry
, iter
) {
269 if (nir_compare_derefs(iter
->dst
, deref
) & allowed_comparisons
)
276 static struct copy_entry
*
277 lookup_entry_and_kill_aliases(struct util_dynarray
*copies
,
278 nir_deref_instr
*deref
,
281 /* TODO: Take into account the write_mask. */
283 nir_deref_instr
*dst_match
= NULL
;
284 util_dynarray_foreach_reverse(copies
, struct copy_entry
, iter
) {
285 if (!iter
->src
.is_ssa
) {
286 /* If this write aliases the source of some entry, get rid of it */
287 if (nir_compare_derefs(iter
->src
.deref
, deref
) & nir_derefs_may_alias_bit
) {
288 copy_entry_remove(copies
, iter
);
293 nir_deref_compare_result comp
= nir_compare_derefs(iter
->dst
, deref
);
295 if (comp
& nir_derefs_equal_bit
) {
296 /* Removing entries invalidate previous iter pointers, so we'll
297 * collect the matching entry later. Just make sure it is unique.
300 dst_match
= iter
->dst
;
301 } else if (comp
& nir_derefs_may_alias_bit
) {
302 copy_entry_remove(copies
, iter
);
306 struct copy_entry
*entry
= NULL
;
308 util_dynarray_foreach(copies
, struct copy_entry
, iter
) {
309 if (iter
->dst
== dst_match
) {
320 kill_aliases(struct util_dynarray
*copies
,
321 nir_deref_instr
*deref
,
324 /* TODO: Take into account the write_mask. */
326 struct copy_entry
*entry
=
327 lookup_entry_and_kill_aliases(copies
, deref
, write_mask
);
329 copy_entry_remove(copies
, entry
);
332 static struct copy_entry
*
333 get_entry_and_kill_aliases(struct util_dynarray
*copies
,
334 nir_deref_instr
*deref
,
337 /* TODO: Take into account the write_mask. */
339 struct copy_entry
*entry
=
340 lookup_entry_and_kill_aliases(copies
, deref
, write_mask
);
343 entry
= copy_entry_create(copies
, deref
);
349 apply_barrier_for_modes(struct util_dynarray
*copies
,
350 nir_variable_mode modes
)
352 util_dynarray_foreach_reverse(copies
, struct copy_entry
, iter
) {
353 if ((iter
->dst
->mode
& modes
) ||
354 (!iter
->src
.is_ssa
&& (iter
->src
.deref
->mode
& modes
)))
355 copy_entry_remove(copies
, iter
);
360 store_to_entry(struct copy_prop_var_state
*state
, struct copy_entry
*entry
,
361 const struct value
*value
, unsigned write_mask
)
364 /* Clear src if it was being used as non-SSA. */
365 if (!entry
->src
.is_ssa
)
366 memset(entry
->src
.ssa
, 0, sizeof(entry
->src
.ssa
));
367 entry
->src
.is_ssa
= true;
368 /* Only overwrite the written components */
369 for (unsigned i
= 0; i
< 4; i
++) {
370 if (write_mask
& (1 << i
))
371 entry
->src
.ssa
[i
] = value
->ssa
[i
];
374 /* Non-ssa stores always write everything */
375 entry
->src
.is_ssa
= false;
376 entry
->src
.deref
= value
->deref
;
380 /* Do a "load" from an SSA-based entry return it in "value" as a value with a
381 * single SSA def. Because an entry could reference up to 4 different SSA
382 * defs, a vecN operation may be inserted to combine them into a single SSA
383 * def before handing it back to the caller. If the load instruction is no
384 * longer needed, it is removed and nir_instr::block is set to NULL. (It is
385 * possible, in some cases, for the load to be used in the vecN operation in
386 * which case it isn't deleted.)
389 load_from_ssa_entry_value(struct copy_prop_var_state
*state
,
390 struct copy_entry
*entry
,
391 nir_builder
*b
, nir_intrinsic_instr
*intrin
,
395 assert(value
->is_ssa
);
397 const struct glsl_type
*type
= entry
->dst
->type
;
398 unsigned num_components
= glsl_get_vector_elements(type
);
400 nir_component_mask_t available
= 0;
401 bool all_same
= true;
402 for (unsigned i
= 0; i
< num_components
; i
++) {
404 available
|= (1 << i
);
406 if (value
->ssa
[i
] != value
->ssa
[0])
411 /* Our work here is done */
412 b
->cursor
= nir_instr_remove(&intrin
->instr
);
413 intrin
->instr
.block
= NULL
;
417 if (available
!= (1 << num_components
) - 1 &&
418 intrin
->intrinsic
== nir_intrinsic_load_deref
&&
419 (available
& nir_ssa_def_components_read(&intrin
->dest
.ssa
)) == 0) {
420 /* If none of the components read are available as SSA values, then we
421 * should just bail. Otherwise, we would end up replacing the uses of
422 * the load_deref a vecN() that just gathers up its components.
427 b
->cursor
= nir_after_instr(&intrin
->instr
);
429 nir_ssa_def
*load_def
=
430 intrin
->intrinsic
== nir_intrinsic_load_deref
? &intrin
->dest
.ssa
: NULL
;
432 bool keep_intrin
= false;
433 nir_ssa_def
*comps
[NIR_MAX_VEC_COMPONENTS
];
434 for (unsigned i
= 0; i
< num_components
; i
++) {
436 comps
[i
] = nir_channel(b
, value
->ssa
[i
], i
);
438 /* We don't have anything for this component in our
439 * list. Just re-use a channel from the load.
441 if (load_def
== NULL
)
442 load_def
= nir_load_deref(b
, entry
->dst
);
444 if (load_def
->parent_instr
== &intrin
->instr
)
447 comps
[i
] = nir_channel(b
, load_def
, i
);
451 nir_ssa_def
*vec
= nir_vec(b
, comps
, num_components
);
452 for (unsigned i
= 0; i
< num_components
; i
++)
456 /* Removing this instruction should not touch the cursor because we
457 * created the cursor after the intrinsic and have added at least one
458 * instruction (the vec) since then.
460 assert(b
->cursor
.instr
!= &intrin
->instr
);
461 nir_instr_remove(&intrin
->instr
);
462 intrin
->instr
.block
= NULL
;
469 * Specialize the wildcards in a deref chain
471 * This function returns a deref chain identical to \param deref except that
472 * some of its wildcards are replaced with indices from \param specific. The
473 * process is guided by \param guide which references the same type as \param
474 * specific but has the same wildcard array lengths as \param deref.
476 static nir_deref_instr
*
477 specialize_wildcards(nir_builder
*b
,
478 nir_deref_path
*deref
,
479 nir_deref_path
*guide
,
480 nir_deref_path
*specific
)
482 nir_deref_instr
**deref_p
= &deref
->path
[1];
483 nir_deref_instr
**guide_p
= &guide
->path
[1];
484 nir_deref_instr
**spec_p
= &specific
->path
[1];
485 nir_deref_instr
*ret_tail
= deref
->path
[0];
486 for (; *deref_p
; deref_p
++) {
487 if ((*deref_p
)->deref_type
== nir_deref_type_array_wildcard
) {
488 /* This is where things get tricky. We have to search through
489 * the entry deref to find its corresponding wildcard and fill
490 * this slot in with the value from the src.
493 (*guide_p
)->deref_type
!= nir_deref_type_array_wildcard
) {
497 assert(*guide_p
&& *spec_p
);
499 ret_tail
= nir_build_deref_follower(b
, ret_tail
, *spec_p
);
504 ret_tail
= nir_build_deref_follower(b
, ret_tail
, *deref_p
);
511 /* Do a "load" from an deref-based entry return it in "value" as a value. The
512 * deref returned in "value" will always be a fresh copy so the caller can
513 * steal it and assign it to the instruction directly without copying it
517 load_from_deref_entry_value(struct copy_prop_var_state
*state
,
518 struct copy_entry
*entry
,
519 nir_builder
*b
, nir_intrinsic_instr
*intrin
,
520 nir_deref_instr
*src
, struct value
*value
)
524 b
->cursor
= nir_instr_remove(&intrin
->instr
);
526 nir_deref_path entry_dst_path
, src_path
;
527 nir_deref_path_init(&entry_dst_path
, entry
->dst
, state
->mem_ctx
);
528 nir_deref_path_init(&src_path
, src
, state
->mem_ctx
);
530 bool need_to_specialize_wildcards
= false;
531 nir_deref_instr
**entry_p
= &entry_dst_path
.path
[1];
532 nir_deref_instr
**src_p
= &src_path
.path
[1];
533 while (*entry_p
&& *src_p
) {
534 nir_deref_instr
*entry_tail
= *entry_p
++;
535 nir_deref_instr
*src_tail
= *src_p
++;
537 if (src_tail
->deref_type
== nir_deref_type_array
&&
538 entry_tail
->deref_type
== nir_deref_type_array_wildcard
)
539 need_to_specialize_wildcards
= true;
542 /* If the entry deref is longer than the source deref then it refers to a
543 * smaller type and we can't source from it.
545 assert(*entry_p
== NULL
);
547 if (need_to_specialize_wildcards
) {
548 /* The entry has some wildcards that are not in src. This means we need
549 * to construct a new deref based on the entry but using the wildcards
550 * from the source and guided by the entry dst. Oof.
552 nir_deref_path entry_src_path
;
553 nir_deref_path_init(&entry_src_path
, entry
->src
.deref
, state
->mem_ctx
);
554 value
->deref
= specialize_wildcards(b
, &entry_src_path
,
555 &entry_dst_path
, &src_path
);
556 nir_deref_path_finish(&entry_src_path
);
559 /* If our source deref is longer than the entry deref, that's ok because
560 * it just means the entry deref needs to be extended a bit.
563 nir_deref_instr
*src_tail
= *src_p
++;
564 value
->deref
= nir_build_deref_follower(b
, value
->deref
, src_tail
);
567 nir_deref_path_finish(&entry_dst_path
);
568 nir_deref_path_finish(&src_path
);
574 try_load_from_entry(struct copy_prop_var_state
*state
, struct copy_entry
*entry
,
575 nir_builder
*b
, nir_intrinsic_instr
*intrin
,
576 nir_deref_instr
*src
, struct value
*value
)
581 if (entry
->src
.is_ssa
) {
582 return load_from_ssa_entry_value(state
, entry
, b
, intrin
, value
);
584 return load_from_deref_entry_value(state
, entry
, b
, intrin
, src
, value
);
589 invalidate_copies_for_cf_node(struct copy_prop_var_state
*state
,
590 struct util_dynarray
*copies
,
591 nir_cf_node
*cf_node
)
593 struct hash_entry
*ht_entry
= _mesa_hash_table_search(state
->vars_written_map
, cf_node
);
596 struct vars_written
*written
= ht_entry
->data
;
597 if (written
->modes
) {
598 util_dynarray_foreach_reverse(copies
, struct copy_entry
, entry
) {
599 if (entry
->dst
->mode
& written
->modes
)
600 copy_entry_remove(copies
, entry
);
604 hash_table_foreach (written
->derefs
, entry
) {
605 nir_deref_instr
*deref_written
= (nir_deref_instr
*)entry
->key
;
606 kill_aliases(copies
, deref_written
, (uintptr_t)entry
->data
);
611 copy_prop_vars_block(struct copy_prop_var_state
*state
,
612 nir_builder
*b
, nir_block
*block
,
613 struct util_dynarray
*copies
)
615 nir_foreach_instr_safe(instr
, block
) {
616 if (instr
->type
== nir_instr_type_call
) {
617 apply_barrier_for_modes(copies
, nir_var_shader_out
|
625 if (instr
->type
!= nir_instr_type_intrinsic
)
628 nir_intrinsic_instr
*intrin
= nir_instr_as_intrinsic(instr
);
629 switch (intrin
->intrinsic
) {
630 case nir_intrinsic_barrier
:
631 case nir_intrinsic_memory_barrier
:
632 apply_barrier_for_modes(copies
, nir_var_shader_out
|
637 case nir_intrinsic_emit_vertex
:
638 case nir_intrinsic_emit_vertex_with_counter
:
639 apply_barrier_for_modes(copies
, nir_var_shader_out
);
642 case nir_intrinsic_load_deref
: {
643 nir_deref_instr
*src
= nir_src_as_deref(intrin
->src
[0]);
645 struct copy_entry
*src_entry
=
646 lookup_entry_for_deref(copies
, src
, nir_derefs_a_contains_b_bit
);
648 if (try_load_from_entry(state
, src_entry
, b
, intrin
, src
, &value
)) {
650 /* lookup_load has already ensured that we get a single SSA
651 * value that has all of the channels. We just have to do the
654 if (intrin
->instr
.block
) {
655 /* The lookup left our instruction in-place. This means it
656 * must have used it to vec up a bunch of different sources.
657 * We need to be careful when rewriting uses so we don't
658 * rewrite the vecN itself.
660 nir_ssa_def_rewrite_uses_after(&intrin
->dest
.ssa
,
661 nir_src_for_ssa(value
.ssa
[0]),
662 value
.ssa
[0]->parent_instr
);
664 nir_ssa_def_rewrite_uses(&intrin
->dest
.ssa
,
665 nir_src_for_ssa(value
.ssa
[0]));
668 /* We're turning it into a load of a different variable */
669 intrin
->src
[0] = nir_src_for_ssa(&value
.deref
->dest
.ssa
);
671 /* Put it back in again. */
672 nir_builder_instr_insert(b
, instr
);
675 for (unsigned i
= 0; i
< intrin
->num_components
; i
++)
676 value
.ssa
[i
] = &intrin
->dest
.ssa
;
678 state
->progress
= true;
681 for (unsigned i
= 0; i
< intrin
->num_components
; i
++)
682 value
.ssa
[i
] = &intrin
->dest
.ssa
;
685 /* Now that we have a value, we're going to store it back so that we
686 * have the right value next time we come looking for it. In order
687 * to do this, we need an exact match, not just something that
688 * contains what we're looking for.
690 struct copy_entry
*store_entry
=
691 lookup_entry_for_deref(copies
, src
, nir_derefs_equal_bit
);
693 store_entry
= copy_entry_create(copies
, src
);
695 /* Set up a store to this entry with the value of the load. This way
696 * we can potentially remove subsequent loads. However, we use a
697 * NULL instruction so we don't try and delete the load on a
700 store_to_entry(state
, store_entry
, &value
,
701 ((1 << intrin
->num_components
) - 1));
705 case nir_intrinsic_store_deref
: {
706 nir_deref_instr
*dst
= nir_src_as_deref(intrin
->src
[0]);
707 struct copy_entry
*entry
=
708 lookup_entry_for_deref(copies
, dst
, nir_derefs_equal_bit
);
709 if (entry
&& value_equals_store_src(&entry
->src
, intrin
)) {
710 /* If we are storing the value from a load of the same var the
711 * store is redundant so remove it.
713 nir_instr_remove(instr
);
715 struct value value
= {
719 for (unsigned i
= 0; i
< intrin
->num_components
; i
++)
720 value
.ssa
[i
] = intrin
->src
[1].ssa
;
722 unsigned wrmask
= nir_intrinsic_write_mask(intrin
);
723 struct copy_entry
*entry
=
724 get_entry_and_kill_aliases(copies
, dst
, wrmask
);
725 store_to_entry(state
, entry
, &value
, wrmask
);
731 case nir_intrinsic_copy_deref
: {
732 nir_deref_instr
*dst
= nir_src_as_deref(intrin
->src
[0]);
733 nir_deref_instr
*src
= nir_src_as_deref(intrin
->src
[1]);
735 if (nir_compare_derefs(src
, dst
) & nir_derefs_equal_bit
) {
736 /* This is a no-op self-copy. Get rid of it */
737 nir_instr_remove(instr
);
741 struct copy_entry
*src_entry
=
742 lookup_entry_for_deref(copies
, src
, nir_derefs_a_contains_b_bit
);
744 if (try_load_from_entry(state
, src_entry
, b
, intrin
, src
, &value
)) {
745 /* If load works, intrin (the copy_deref) is removed. */
747 nir_store_deref(b
, dst
, value
.ssa
[0], 0xf);
749 /* If this would be a no-op self-copy, don't bother. */
750 if (nir_compare_derefs(value
.deref
, dst
) & nir_derefs_equal_bit
)
753 /* Just turn it into a copy of a different deref */
754 intrin
->src
[1] = nir_src_for_ssa(&value
.deref
->dest
.ssa
);
756 /* Put it back in again. */
757 nir_builder_instr_insert(b
, instr
);
760 state
->progress
= true;
762 value
= (struct value
) {
768 struct copy_entry
*dst_entry
=
769 get_entry_and_kill_aliases(copies
, dst
, 0xf);
770 store_to_entry(state
, dst_entry
, &value
, 0xf);
781 copy_prop_vars_cf_node(struct copy_prop_var_state
*state
,
782 struct util_dynarray
*copies
,
783 nir_cf_node
*cf_node
)
785 switch (cf_node
->type
) {
786 case nir_cf_node_function
: {
787 nir_function_impl
*impl
= nir_cf_node_as_function(cf_node
);
789 struct util_dynarray impl_copies
;
790 util_dynarray_init(&impl_copies
, state
->mem_ctx
);
792 foreach_list_typed_safe(nir_cf_node
, cf_node
, node
, &impl
->body
)
793 copy_prop_vars_cf_node(state
, &impl_copies
, cf_node
);
798 case nir_cf_node_block
: {
799 nir_block
*block
= nir_cf_node_as_block(cf_node
);
801 nir_builder_init(&b
, state
->impl
);
802 copy_prop_vars_block(state
, &b
, block
, copies
);
806 case nir_cf_node_if
: {
807 nir_if
*if_stmt
= nir_cf_node_as_if(cf_node
);
809 /* Clone the copies for each branch of the if statement. The idea is
810 * that they both see the same state of available copies, but do not
811 * interfere to each other.
814 struct util_dynarray then_copies
;
815 util_dynarray_clone(&then_copies
, state
->mem_ctx
, copies
);
817 struct util_dynarray else_copies
;
818 util_dynarray_clone(&else_copies
, state
->mem_ctx
, copies
);
820 foreach_list_typed_safe(nir_cf_node
, cf_node
, node
, &if_stmt
->then_list
)
821 copy_prop_vars_cf_node(state
, &then_copies
, cf_node
);
823 foreach_list_typed_safe(nir_cf_node
, cf_node
, node
, &if_stmt
->else_list
)
824 copy_prop_vars_cf_node(state
, &else_copies
, cf_node
);
826 /* Both branches copies can be ignored, since the effect of running both
827 * branches was captured in the first pass that collects vars_written.
830 invalidate_copies_for_cf_node(state
, copies
, cf_node
);
835 case nir_cf_node_loop
: {
836 nir_loop
*loop
= nir_cf_node_as_loop(cf_node
);
838 /* Invalidate before cloning the copies for the loop, since the loop
839 * body can be executed more than once.
842 invalidate_copies_for_cf_node(state
, copies
, cf_node
);
844 struct util_dynarray loop_copies
;
845 util_dynarray_clone(&loop_copies
, state
->mem_ctx
, copies
);
847 foreach_list_typed_safe(nir_cf_node
, cf_node
, node
, &loop
->body
)
848 copy_prop_vars_cf_node(state
, &loop_copies
, cf_node
);
854 unreachable("Invalid CF node type");
859 nir_copy_prop_vars_impl(nir_function_impl
*impl
)
861 void *mem_ctx
= ralloc_context(NULL
);
863 struct copy_prop_var_state state
= {
866 .lin_ctx
= linear_zalloc_parent(mem_ctx
, 0),
868 .vars_written_map
= _mesa_hash_table_create(mem_ctx
, _mesa_hash_pointer
,
869 _mesa_key_pointer_equal
),
872 gather_vars_written(&state
, NULL
, &impl
->cf_node
);
874 copy_prop_vars_cf_node(&state
, NULL
, &impl
->cf_node
);
876 if (state
.progress
) {
877 nir_metadata_preserve(impl
, nir_metadata_block_index
|
878 nir_metadata_dominance
);
881 impl
->valid_metadata
&= ~nir_metadata_not_properly_reset
;
885 ralloc_free(mem_ctx
);
886 return state
.progress
;
890 nir_opt_copy_prop_vars(nir_shader
*shader
)
892 bool progress
= false;
894 nir_foreach_function(function
, shader
) {
897 progress
|= nir_copy_prop_vars_impl(function
->impl
);