2 * Copyright © 2018 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"
30 #include "util/u_math.h"
33 get_complex_used_vars(nir_shader
*shader
, void *mem_ctx
)
35 struct set
*complex_vars
= _mesa_pointer_set_create(mem_ctx
);
37 nir_foreach_function(function
, shader
) {
41 nir_foreach_block(block
, function
->impl
) {
42 nir_foreach_instr(instr
, block
) {
43 if (instr
->type
!= nir_instr_type_deref
)
46 nir_deref_instr
*deref
= nir_instr_as_deref(instr
);
48 /* We only need to consider var derefs because
49 * nir_deref_instr_has_complex_use is recursive.
51 if (deref
->deref_type
== nir_deref_type_var
&&
52 nir_deref_instr_has_complex_use(deref
))
53 _mesa_set_add(complex_vars
, deref
->var
);
61 struct split_var_state
{
65 nir_function_impl
*impl
;
67 nir_variable
*base_var
;
73 const struct glsl_type
*type
;
81 static const struct glsl_type
*
82 wrap_type_in_array(const struct glsl_type
*type
,
83 const struct glsl_type
*array_type
)
85 if (!glsl_type_is_array(array_type
))
88 const struct glsl_type
*elem_type
=
89 wrap_type_in_array(type
, glsl_get_array_element(array_type
));
90 assert(glsl_get_explicit_stride(array_type
) == 0);
91 return glsl_array_type(elem_type
, glsl_get_length(array_type
), 0);
95 num_array_levels_in_array_of_vector_type(const struct glsl_type
*type
)
99 if (glsl_type_is_array_or_matrix(type
)) {
101 type
= glsl_get_array_element(type
);
102 } else if (glsl_type_is_vector_or_scalar(type
)) {
105 /* Not an array of vectors */
112 init_field_for_type(struct field
*field
, struct field
*parent
,
113 const struct glsl_type
*type
,
115 struct split_var_state
*state
)
117 *field
= (struct field
) {
122 const struct glsl_type
*struct_type
= glsl_without_array(type
);
123 if (glsl_type_is_struct_or_ifc(struct_type
)) {
124 field
->num_fields
= glsl_get_length(struct_type
),
125 field
->fields
= ralloc_array(state
->mem_ctx
, struct field
,
127 for (unsigned i
= 0; i
< field
->num_fields
; i
++) {
128 char *field_name
= NULL
;
130 field_name
= ralloc_asprintf(state
->mem_ctx
, "%s_%s", name
,
131 glsl_get_struct_elem_name(struct_type
, i
));
133 field_name
= ralloc_asprintf(state
->mem_ctx
, "{unnamed %s}_%s",
134 glsl_get_type_name(struct_type
),
135 glsl_get_struct_elem_name(struct_type
, i
));
137 init_field_for_type(&field
->fields
[i
], field
,
138 glsl_get_struct_field(struct_type
, i
),
142 const struct glsl_type
*var_type
= type
;
143 for (struct field
*f
= field
->parent
; f
; f
= f
->parent
)
144 var_type
= wrap_type_in_array(var_type
, f
->type
);
146 nir_variable_mode mode
= state
->base_var
->data
.mode
;
147 if (mode
== nir_var_function_temp
) {
148 field
->var
= nir_local_variable_create(state
->impl
, var_type
, name
);
150 field
->var
= nir_variable_create(state
->shader
, mode
, var_type
, name
);
156 split_var_list_structs(nir_shader
*shader
,
157 nir_function_impl
*impl
,
158 struct exec_list
*vars
,
159 struct hash_table
*var_field_map
,
160 struct set
**complex_vars
,
163 struct split_var_state state
= {
169 struct exec_list split_vars
;
170 exec_list_make_empty(&split_vars
);
172 /* To avoid list confusion (we'll be adding things as we split variables),
173 * pull all of the variables we plan to split off of the list
175 nir_foreach_variable_safe(var
, vars
) {
176 if (!glsl_type_is_struct_or_ifc(glsl_without_array(var
->type
)))
179 if (*complex_vars
== NULL
)
180 *complex_vars
= get_complex_used_vars(shader
, mem_ctx
);
182 /* We can't split a variable that's referenced with deref that has any
183 * sort of complex usage.
185 if (_mesa_set_search(*complex_vars
, var
))
188 exec_node_remove(&var
->node
);
189 exec_list_push_tail(&split_vars
, &var
->node
);
192 nir_foreach_variable(var
, &split_vars
) {
193 state
.base_var
= var
;
195 struct field
*root_field
= ralloc(mem_ctx
, struct field
);
196 init_field_for_type(root_field
, NULL
, var
->type
, var
->name
, &state
);
197 _mesa_hash_table_insert(var_field_map
, var
, root_field
);
200 return !exec_list_is_empty(&split_vars
);
204 split_struct_derefs_impl(nir_function_impl
*impl
,
205 struct hash_table
*var_field_map
,
206 nir_variable_mode modes
,
210 nir_builder_init(&b
, impl
);
212 nir_foreach_block(block
, impl
) {
213 nir_foreach_instr_safe(instr
, block
) {
214 if (instr
->type
!= nir_instr_type_deref
)
217 nir_deref_instr
*deref
= nir_instr_as_deref(instr
);
218 if (!(deref
->mode
& modes
))
221 /* Clean up any dead derefs we find lying around. They may refer to
222 * variables we're planning to split.
224 if (nir_deref_instr_remove_if_unused(deref
))
227 if (!glsl_type_is_vector_or_scalar(deref
->type
))
230 nir_variable
*base_var
= nir_deref_instr_get_variable(deref
);
231 struct hash_entry
*entry
=
232 _mesa_hash_table_search(var_field_map
, base_var
);
236 struct field
*root_field
= entry
->data
;
239 nir_deref_path_init(&path
, deref
, mem_ctx
);
241 struct field
*tail_field
= root_field
;
242 for (unsigned i
= 0; path
.path
[i
]; i
++) {
243 if (path
.path
[i
]->deref_type
!= nir_deref_type_struct
)
247 assert(glsl_type_is_struct_or_ifc(path
.path
[i
- 1]->type
));
248 assert(path
.path
[i
- 1]->type
==
249 glsl_without_array(tail_field
->type
));
251 tail_field
= &tail_field
->fields
[path
.path
[i
]->strct
.index
];
253 nir_variable
*split_var
= tail_field
->var
;
255 nir_deref_instr
*new_deref
= NULL
;
256 for (unsigned i
= 0; path
.path
[i
]; i
++) {
257 nir_deref_instr
*p
= path
.path
[i
];
258 b
.cursor
= nir_after_instr(&p
->instr
);
260 switch (p
->deref_type
) {
261 case nir_deref_type_var
:
262 assert(new_deref
== NULL
);
263 new_deref
= nir_build_deref_var(&b
, split_var
);
266 case nir_deref_type_array
:
267 case nir_deref_type_array_wildcard
:
268 new_deref
= nir_build_deref_follower(&b
, new_deref
, p
);
271 case nir_deref_type_struct
:
272 /* Nothing to do; we're splitting structs */
276 unreachable("Invalid deref type in path");
280 assert(new_deref
->type
== deref
->type
);
281 nir_ssa_def_rewrite_uses(&deref
->dest
.ssa
,
282 nir_src_for_ssa(&new_deref
->dest
.ssa
));
283 nir_deref_instr_remove_if_unused(deref
);
288 /** A pass for splitting structs into multiple variables
290 * This pass splits arrays of structs into multiple variables, one for each
291 * (possibly nested) structure member. After this pass completes, no
292 * variables of the given mode will contain a struct type.
295 nir_split_struct_vars(nir_shader
*shader
, nir_variable_mode modes
)
297 void *mem_ctx
= ralloc_context(NULL
);
298 struct hash_table
*var_field_map
=
299 _mesa_pointer_hash_table_create(mem_ctx
);
300 struct set
*complex_vars
= NULL
;
302 assert((modes
& (nir_var_shader_temp
| nir_var_function_temp
)) == modes
);
304 bool has_global_splits
= false;
305 if (modes
& nir_var_shader_temp
) {
306 has_global_splits
= split_var_list_structs(shader
, NULL
,
313 bool progress
= false;
314 nir_foreach_function(function
, shader
) {
318 bool has_local_splits
= false;
319 if (modes
& nir_var_function_temp
) {
320 has_local_splits
= split_var_list_structs(shader
, function
->impl
,
321 &function
->impl
->locals
,
327 if (has_global_splits
|| has_local_splits
) {
328 split_struct_derefs_impl(function
->impl
, var_field_map
,
331 nir_metadata_preserve(function
->impl
, nir_metadata_block_index
|
332 nir_metadata_dominance
);
335 nir_metadata_preserve(function
->impl
, nir_metadata_all
);
339 ralloc_free(mem_ctx
);
344 struct array_level_info
{
350 /* Only set if this is the tail end of the splitting */
354 struct array_split
*splits
;
357 struct array_var_info
{
358 nir_variable
*base_var
;
360 const struct glsl_type
*split_var_type
;
363 struct array_split root_split
;
366 struct array_level_info levels
[0];
370 init_var_list_array_infos(nir_shader
*shader
,
371 struct exec_list
*vars
,
372 struct hash_table
*var_info_map
,
373 struct set
**complex_vars
,
376 bool has_array
= false;
378 nir_foreach_variable(var
, vars
) {
379 int num_levels
= num_array_levels_in_array_of_vector_type(var
->type
);
383 if (*complex_vars
== NULL
)
384 *complex_vars
= get_complex_used_vars(shader
, mem_ctx
);
386 /* We can't split a variable that's referenced with deref that has any
387 * sort of complex usage.
389 if (_mesa_set_search(*complex_vars
, var
))
392 struct array_var_info
*info
=
393 rzalloc_size(mem_ctx
, sizeof(*info
) +
394 num_levels
* sizeof(info
->levels
[0]));
396 info
->base_var
= var
;
397 info
->num_levels
= num_levels
;
399 const struct glsl_type
*type
= var
->type
;
400 for (int i
= 0; i
< num_levels
; i
++) {
401 info
->levels
[i
].array_len
= glsl_get_length(type
);
402 type
= glsl_get_array_element(type
);
404 /* All levels start out initially as split */
405 info
->levels
[i
].split
= true;
408 _mesa_hash_table_insert(var_info_map
, var
, info
);
415 static struct array_var_info
*
416 get_array_var_info(nir_variable
*var
,
417 struct hash_table
*var_info_map
)
419 struct hash_entry
*entry
=
420 _mesa_hash_table_search(var_info_map
, var
);
421 return entry
? entry
->data
: NULL
;
424 static struct array_var_info
*
425 get_array_deref_info(nir_deref_instr
*deref
,
426 struct hash_table
*var_info_map
,
427 nir_variable_mode modes
)
429 if (!(deref
->mode
& modes
))
432 nir_variable
*var
= nir_deref_instr_get_variable(deref
);
436 return get_array_var_info(var
, var_info_map
);
440 mark_array_deref_used(nir_deref_instr
*deref
,
441 struct hash_table
*var_info_map
,
442 nir_variable_mode modes
,
445 struct array_var_info
*info
=
446 get_array_deref_info(deref
, var_info_map
, modes
);
451 nir_deref_path_init(&path
, deref
, mem_ctx
);
453 /* Walk the path and look for indirects. If we have an array deref with an
454 * indirect, mark the given level as not being split.
456 for (unsigned i
= 0; i
< info
->num_levels
; i
++) {
457 nir_deref_instr
*p
= path
.path
[i
+ 1];
458 if (p
->deref_type
== nir_deref_type_array
&&
459 !nir_src_is_const(p
->arr
.index
))
460 info
->levels
[i
].split
= false;
465 mark_array_usage_impl(nir_function_impl
*impl
,
466 struct hash_table
*var_info_map
,
467 nir_variable_mode modes
,
470 nir_foreach_block(block
, impl
) {
471 nir_foreach_instr(instr
, block
) {
472 if (instr
->type
!= nir_instr_type_intrinsic
)
475 nir_intrinsic_instr
*intrin
= nir_instr_as_intrinsic(instr
);
476 switch (intrin
->intrinsic
) {
477 case nir_intrinsic_copy_deref
:
478 mark_array_deref_used(nir_src_as_deref(intrin
->src
[1]),
479 var_info_map
, modes
, mem_ctx
);
482 case nir_intrinsic_load_deref
:
483 case nir_intrinsic_store_deref
:
484 mark_array_deref_used(nir_src_as_deref(intrin
->src
[0]),
485 var_info_map
, modes
, mem_ctx
);
496 create_split_array_vars(struct array_var_info
*var_info
,
498 struct array_split
*split
,
501 nir_function_impl
*impl
,
504 while (level
< var_info
->num_levels
&& !var_info
->levels
[level
].split
) {
505 name
= ralloc_asprintf(mem_ctx
, "%s[*]", name
);
509 if (level
== var_info
->num_levels
) {
510 /* We add parens to the variable name so it looks like "(foo[2][*])" so
511 * that further derefs will look like "(foo[2][*])[ssa_6]"
513 name
= ralloc_asprintf(mem_ctx
, "(%s)", name
);
515 nir_variable_mode mode
= var_info
->base_var
->data
.mode
;
516 if (mode
== nir_var_function_temp
) {
517 split
->var
= nir_local_variable_create(impl
,
518 var_info
->split_var_type
, name
);
520 split
->var
= nir_variable_create(shader
, mode
,
521 var_info
->split_var_type
, name
);
524 assert(var_info
->levels
[level
].split
);
525 split
->num_splits
= var_info
->levels
[level
].array_len
;
526 split
->splits
= rzalloc_array(mem_ctx
, struct array_split
,
528 for (unsigned i
= 0; i
< split
->num_splits
; i
++) {
529 create_split_array_vars(var_info
, level
+ 1, &split
->splits
[i
],
530 ralloc_asprintf(mem_ctx
, "%s[%d]", name
, i
),
531 shader
, impl
, mem_ctx
);
537 split_var_list_arrays(nir_shader
*shader
,
538 nir_function_impl
*impl
,
539 struct exec_list
*vars
,
540 struct hash_table
*var_info_map
,
543 struct exec_list split_vars
;
544 exec_list_make_empty(&split_vars
);
546 nir_foreach_variable_safe(var
, vars
) {
547 struct array_var_info
*info
= get_array_var_info(var
, var_info_map
);
551 bool has_split
= false;
552 const struct glsl_type
*split_type
=
553 glsl_without_array_or_matrix(var
->type
);
554 for (int i
= info
->num_levels
- 1; i
>= 0; i
--) {
555 if (info
->levels
[i
].split
) {
560 /* If the original type was a matrix type, we'd like to keep that so
561 * we don't convert matrices into arrays.
563 if (i
== info
->num_levels
- 1 &&
564 glsl_type_is_matrix(glsl_without_array(var
->type
))) {
565 split_type
= glsl_matrix_type(glsl_get_base_type(split_type
),
566 glsl_get_components(split_type
),
567 info
->levels
[i
].array_len
);
569 split_type
= glsl_array_type(split_type
, info
->levels
[i
].array_len
, 0);
574 info
->split_var_type
= split_type
;
575 /* To avoid list confusion (we'll be adding things as we split
576 * variables), pull all of the variables we plan to split off of the
577 * main variable list.
579 exec_node_remove(&var
->node
);
580 exec_list_push_tail(&split_vars
, &var
->node
);
582 assert(split_type
== glsl_get_bare_type(var
->type
));
583 /* If we're not modifying this variable, delete the info so we skip
584 * it faster in later passes.
586 _mesa_hash_table_remove_key(var_info_map
, var
);
590 nir_foreach_variable(var
, &split_vars
) {
591 struct array_var_info
*info
= get_array_var_info(var
, var_info_map
);
592 create_split_array_vars(info
, 0, &info
->root_split
, var
->name
,
593 shader
, impl
, mem_ctx
);
596 return !exec_list_is_empty(&split_vars
);
600 deref_has_split_wildcard(nir_deref_path
*path
,
601 struct array_var_info
*info
)
606 assert(path
->path
[0]->var
== info
->base_var
);
607 for (unsigned i
= 0; i
< info
->num_levels
; i
++) {
608 if (path
->path
[i
+ 1]->deref_type
== nir_deref_type_array_wildcard
&&
609 info
->levels
[i
].split
)
617 array_path_is_out_of_bounds(nir_deref_path
*path
,
618 struct array_var_info
*info
)
623 assert(path
->path
[0]->var
== info
->base_var
);
624 for (unsigned i
= 0; i
< info
->num_levels
; i
++) {
625 nir_deref_instr
*p
= path
->path
[i
+ 1];
626 if (p
->deref_type
== nir_deref_type_array_wildcard
)
629 if (nir_src_is_const(p
->arr
.index
) &&
630 nir_src_as_uint(p
->arr
.index
) >= info
->levels
[i
].array_len
)
638 emit_split_copies(nir_builder
*b
,
639 struct array_var_info
*dst_info
, nir_deref_path
*dst_path
,
640 unsigned dst_level
, nir_deref_instr
*dst
,
641 struct array_var_info
*src_info
, nir_deref_path
*src_path
,
642 unsigned src_level
, nir_deref_instr
*src
)
644 nir_deref_instr
*dst_p
, *src_p
;
646 while ((dst_p
= dst_path
->path
[dst_level
+ 1])) {
647 if (dst_p
->deref_type
== nir_deref_type_array_wildcard
)
650 dst
= nir_build_deref_follower(b
, dst
, dst_p
);
654 while ((src_p
= src_path
->path
[src_level
+ 1])) {
655 if (src_p
->deref_type
== nir_deref_type_array_wildcard
)
658 src
= nir_build_deref_follower(b
, src
, src_p
);
662 if (src_p
== NULL
|| dst_p
== NULL
) {
663 assert(src_p
== NULL
&& dst_p
== NULL
);
664 nir_copy_deref(b
, dst
, src
);
666 assert(dst_p
->deref_type
== nir_deref_type_array_wildcard
&&
667 src_p
->deref_type
== nir_deref_type_array_wildcard
);
669 if ((dst_info
&& dst_info
->levels
[dst_level
].split
) ||
670 (src_info
&& src_info
->levels
[src_level
].split
)) {
671 /* There are no indirects at this level on one of the source or the
672 * destination so we are lowering it.
674 assert(glsl_get_length(dst_path
->path
[dst_level
]->type
) ==
675 glsl_get_length(src_path
->path
[src_level
]->type
));
676 unsigned len
= glsl_get_length(dst_path
->path
[dst_level
]->type
);
677 for (unsigned i
= 0; i
< len
; i
++) {
678 emit_split_copies(b
, dst_info
, dst_path
, dst_level
+ 1,
679 nir_build_deref_array_imm(b
, dst
, i
),
680 src_info
, src_path
, src_level
+ 1,
681 nir_build_deref_array_imm(b
, src
, i
));
684 /* Neither side is being split so we just keep going */
685 emit_split_copies(b
, dst_info
, dst_path
, dst_level
+ 1,
686 nir_build_deref_array_wildcard(b
, dst
),
687 src_info
, src_path
, src_level
+ 1,
688 nir_build_deref_array_wildcard(b
, src
));
694 split_array_copies_impl(nir_function_impl
*impl
,
695 struct hash_table
*var_info_map
,
696 nir_variable_mode modes
,
700 nir_builder_init(&b
, impl
);
702 nir_foreach_block(block
, impl
) {
703 nir_foreach_instr_safe(instr
, block
) {
704 if (instr
->type
!= nir_instr_type_intrinsic
)
707 nir_intrinsic_instr
*copy
= nir_instr_as_intrinsic(instr
);
708 if (copy
->intrinsic
!= nir_intrinsic_copy_deref
)
711 nir_deref_instr
*dst_deref
= nir_src_as_deref(copy
->src
[0]);
712 nir_deref_instr
*src_deref
= nir_src_as_deref(copy
->src
[1]);
714 struct array_var_info
*dst_info
=
715 get_array_deref_info(dst_deref
, var_info_map
, modes
);
716 struct array_var_info
*src_info
=
717 get_array_deref_info(src_deref
, var_info_map
, modes
);
719 if (!src_info
&& !dst_info
)
722 nir_deref_path dst_path
, src_path
;
723 nir_deref_path_init(&dst_path
, dst_deref
, mem_ctx
);
724 nir_deref_path_init(&src_path
, src_deref
, mem_ctx
);
726 if (!deref_has_split_wildcard(&dst_path
, dst_info
) &&
727 !deref_has_split_wildcard(&src_path
, src_info
))
730 b
.cursor
= nir_instr_remove(©
->instr
);
732 emit_split_copies(&b
, dst_info
, &dst_path
, 0, dst_path
.path
[0],
733 src_info
, &src_path
, 0, src_path
.path
[0]);
739 split_array_access_impl(nir_function_impl
*impl
,
740 struct hash_table
*var_info_map
,
741 nir_variable_mode modes
,
745 nir_builder_init(&b
, impl
);
747 nir_foreach_block(block
, impl
) {
748 nir_foreach_instr_safe(instr
, block
) {
749 if (instr
->type
== nir_instr_type_deref
) {
750 /* Clean up any dead derefs we find lying around. They may refer
751 * to variables we're planning to split.
753 nir_deref_instr
*deref
= nir_instr_as_deref(instr
);
754 if (deref
->mode
& modes
)
755 nir_deref_instr_remove_if_unused(deref
);
759 if (instr
->type
!= nir_instr_type_intrinsic
)
762 nir_intrinsic_instr
*intrin
= nir_instr_as_intrinsic(instr
);
763 if (intrin
->intrinsic
!= nir_intrinsic_load_deref
&&
764 intrin
->intrinsic
!= nir_intrinsic_store_deref
&&
765 intrin
->intrinsic
!= nir_intrinsic_copy_deref
)
768 const unsigned num_derefs
=
769 intrin
->intrinsic
== nir_intrinsic_copy_deref
? 2 : 1;
771 for (unsigned d
= 0; d
< num_derefs
; d
++) {
772 nir_deref_instr
*deref
= nir_src_as_deref(intrin
->src
[d
]);
774 struct array_var_info
*info
=
775 get_array_deref_info(deref
, var_info_map
, modes
);
780 nir_deref_path_init(&path
, deref
, mem_ctx
);
782 b
.cursor
= nir_before_instr(&intrin
->instr
);
784 if (array_path_is_out_of_bounds(&path
, info
)) {
785 /* If one of the derefs is out-of-bounds, we just delete the
786 * instruction. If a destination is out of bounds, then it may
787 * have been in-bounds prior to shrinking so we don't want to
788 * accidentally stomp something. However, we've already proven
789 * that it will never be read so it's safe to delete. If a
790 * source is out of bounds then it is loading random garbage.
791 * For loads, we replace their uses with an undef instruction
792 * and for copies we just delete the copy since it was writing
793 * undefined garbage anyway and we may as well leave the random
794 * garbage in the destination alone.
796 if (intrin
->intrinsic
== nir_intrinsic_load_deref
) {
798 nir_ssa_undef(&b
, intrin
->dest
.ssa
.num_components
,
799 intrin
->dest
.ssa
.bit_size
);
800 nir_ssa_def_rewrite_uses(&intrin
->dest
.ssa
,
803 nir_instr_remove(&intrin
->instr
);
804 for (unsigned i
= 0; i
< num_derefs
; i
++)
805 nir_deref_instr_remove_if_unused(nir_src_as_deref(intrin
->src
[i
]));
809 struct array_split
*split
= &info
->root_split
;
810 for (unsigned i
= 0; i
< info
->num_levels
; i
++) {
811 if (info
->levels
[i
].split
) {
812 nir_deref_instr
*p
= path
.path
[i
+ 1];
813 unsigned index
= nir_src_as_uint(p
->arr
.index
);
814 assert(index
< info
->levels
[i
].array_len
);
815 split
= &split
->splits
[index
];
818 assert(!split
->splits
&& split
->var
);
820 nir_deref_instr
*new_deref
= nir_build_deref_var(&b
, split
->var
);
821 for (unsigned i
= 0; i
< info
->num_levels
; i
++) {
822 if (!info
->levels
[i
].split
) {
823 new_deref
= nir_build_deref_follower(&b
, new_deref
,
827 assert(new_deref
->type
== deref
->type
);
829 /* Rewrite the deref source to point to the split one */
830 nir_instr_rewrite_src(&intrin
->instr
, &intrin
->src
[d
],
831 nir_src_for_ssa(&new_deref
->dest
.ssa
));
832 nir_deref_instr_remove_if_unused(deref
);
838 /** A pass for splitting arrays of vectors into multiple variables
840 * This pass looks at arrays (possibly multiple levels) of vectors (not
841 * structures or other types) and tries to split them into piles of variables,
842 * one for each array element. The heuristic used is simple: If a given array
843 * level is never used with an indirect, that array level will get split.
845 * This pass probably could handles structures easily enough but making a pass
846 * that could see through an array of structures of arrays would be difficult
847 * so it's best to just run nir_split_struct_vars first.
850 nir_split_array_vars(nir_shader
*shader
, nir_variable_mode modes
)
852 void *mem_ctx
= ralloc_context(NULL
);
853 struct hash_table
*var_info_map
= _mesa_pointer_hash_table_create(mem_ctx
);
854 struct set
*complex_vars
= NULL
;
856 assert((modes
& (nir_var_shader_temp
| nir_var_function_temp
)) == modes
);
858 bool has_global_array
= false;
859 if (modes
& nir_var_shader_temp
) {
860 has_global_array
= init_var_list_array_infos(shader
,
867 bool has_any_array
= false;
868 nir_foreach_function(function
, shader
) {
872 bool has_local_array
= false;
873 if (modes
& nir_var_function_temp
) {
874 has_local_array
= init_var_list_array_infos(shader
,
875 &function
->impl
->locals
,
881 if (has_global_array
|| has_local_array
) {
882 has_any_array
= true;
883 mark_array_usage_impl(function
->impl
, var_info_map
, modes
, mem_ctx
);
887 /* If we failed to find any arrays of arrays, bail early. */
888 if (!has_any_array
) {
889 ralloc_free(mem_ctx
);
893 bool has_global_splits
= false;
894 if (modes
& nir_var_shader_temp
) {
895 has_global_splits
= split_var_list_arrays(shader
, NULL
,
897 var_info_map
, mem_ctx
);
900 bool progress
= false;
901 nir_foreach_function(function
, shader
) {
905 bool has_local_splits
= false;
906 if (modes
& nir_var_function_temp
) {
907 has_local_splits
= split_var_list_arrays(shader
, function
->impl
,
908 &function
->impl
->locals
,
909 var_info_map
, mem_ctx
);
912 if (has_global_splits
|| has_local_splits
) {
913 split_array_copies_impl(function
->impl
, var_info_map
, modes
, mem_ctx
);
914 split_array_access_impl(function
->impl
, var_info_map
, modes
, mem_ctx
);
916 nir_metadata_preserve(function
->impl
, nir_metadata_block_index
|
917 nir_metadata_dominance
);
920 nir_metadata_preserve(function
->impl
, nir_metadata_all
);
924 ralloc_free(mem_ctx
);
929 struct array_level_usage
{
932 /* The value UINT_MAX will be used to indicate an indirect */
934 unsigned max_written
;
936 /* True if there is a copy that isn't to/from a shrinkable array */
937 bool has_external_copy
;
938 struct set
*levels_copied
;
941 struct vec_var_usage
{
942 /* Convenience set of all components this variable has */
943 nir_component_mask_t all_comps
;
945 nir_component_mask_t comps_read
;
946 nir_component_mask_t comps_written
;
948 nir_component_mask_t comps_kept
;
950 /* True if there is a copy that isn't to/from a shrinkable vector */
951 bool has_external_copy
;
952 bool has_complex_use
;
953 struct set
*vars_copied
;
956 struct array_level_usage levels
[0];
959 static struct vec_var_usage
*
960 get_vec_var_usage(nir_variable
*var
,
961 struct hash_table
*var_usage_map
,
962 bool add_usage_entry
, void *mem_ctx
)
964 struct hash_entry
*entry
= _mesa_hash_table_search(var_usage_map
, var
);
968 if (!add_usage_entry
)
971 /* Check to make sure that we are working with an array of vectors. We
972 * don't bother to shrink single vectors because we figure that we can
973 * clean it up better with SSA than by inserting piles of vecN instructions
974 * to compact results.
976 int num_levels
= num_array_levels_in_array_of_vector_type(var
->type
);
978 return NULL
; /* Not an array of vectors */
980 struct vec_var_usage
*usage
=
981 rzalloc_size(mem_ctx
, sizeof(*usage
) +
982 num_levels
* sizeof(usage
->levels
[0]));
984 usage
->num_levels
= num_levels
;
985 const struct glsl_type
*type
= var
->type
;
986 for (unsigned i
= 0; i
< num_levels
; i
++) {
987 usage
->levels
[i
].array_len
= glsl_get_length(type
);
988 type
= glsl_get_array_element(type
);
990 assert(glsl_type_is_vector_or_scalar(type
));
992 usage
->all_comps
= (1 << glsl_get_components(type
)) - 1;
994 _mesa_hash_table_insert(var_usage_map
, var
, usage
);
999 static struct vec_var_usage
*
1000 get_vec_deref_usage(nir_deref_instr
*deref
,
1001 struct hash_table
*var_usage_map
,
1002 nir_variable_mode modes
,
1003 bool add_usage_entry
, void *mem_ctx
)
1005 if (!(deref
->mode
& modes
))
1008 return get_vec_var_usage(nir_deref_instr_get_variable(deref
),
1009 var_usage_map
, add_usage_entry
, mem_ctx
);
1013 mark_deref_if_complex(nir_deref_instr
*deref
,
1014 struct hash_table
*var_usage_map
,
1015 nir_variable_mode modes
,
1018 if (!(deref
->mode
& modes
))
1021 /* Only bother with var derefs because nir_deref_instr_has_complex_use is
1024 if (deref
->deref_type
!= nir_deref_type_var
)
1027 if (!nir_deref_instr_has_complex_use(deref
))
1030 struct vec_var_usage
*usage
=
1031 get_vec_var_usage(deref
->var
, var_usage_map
, true, mem_ctx
);
1035 usage
->has_complex_use
= true;
1039 mark_deref_used(nir_deref_instr
*deref
,
1040 nir_component_mask_t comps_read
,
1041 nir_component_mask_t comps_written
,
1042 nir_deref_instr
*copy_deref
,
1043 struct hash_table
*var_usage_map
,
1044 nir_variable_mode modes
,
1047 if (!(deref
->mode
& modes
))
1050 nir_variable
*var
= nir_deref_instr_get_variable(deref
);
1054 struct vec_var_usage
*usage
=
1055 get_vec_var_usage(var
, var_usage_map
, true, mem_ctx
);
1059 usage
->comps_read
|= comps_read
& usage
->all_comps
;
1060 usage
->comps_written
|= comps_written
& usage
->all_comps
;
1062 struct vec_var_usage
*copy_usage
= NULL
;
1064 copy_usage
= get_vec_deref_usage(copy_deref
, var_usage_map
, modes
,
1067 if (usage
->vars_copied
== NULL
) {
1068 usage
->vars_copied
= _mesa_pointer_set_create(mem_ctx
);
1070 _mesa_set_add(usage
->vars_copied
, copy_usage
);
1072 usage
->has_external_copy
= true;
1076 nir_deref_path path
;
1077 nir_deref_path_init(&path
, deref
, mem_ctx
);
1079 nir_deref_path copy_path
;
1081 nir_deref_path_init(©_path
, copy_deref
, mem_ctx
);
1083 unsigned copy_i
= 0;
1084 for (unsigned i
= 0; i
< usage
->num_levels
; i
++) {
1085 struct array_level_usage
*level
= &usage
->levels
[i
];
1086 nir_deref_instr
*deref
= path
.path
[i
+ 1];
1087 assert(deref
->deref_type
== nir_deref_type_array
||
1088 deref
->deref_type
== nir_deref_type_array_wildcard
);
1091 if (deref
->deref_type
== nir_deref_type_array
) {
1092 max_used
= nir_src_is_const(deref
->arr
.index
) ?
1093 nir_src_as_uint(deref
->arr
.index
) : UINT_MAX
;
1095 /* For wildcards, we read or wrote the whole thing. */
1096 assert(deref
->deref_type
== nir_deref_type_array_wildcard
);
1097 max_used
= level
->array_len
- 1;
1100 /* Match each wildcard level with the level on copy_usage */
1101 for (; copy_path
.path
[copy_i
+ 1]; copy_i
++) {
1102 if (copy_path
.path
[copy_i
+ 1]->deref_type
==
1103 nir_deref_type_array_wildcard
)
1106 struct array_level_usage
*copy_level
=
1107 ©_usage
->levels
[copy_i
++];
1109 if (level
->levels_copied
== NULL
) {
1110 level
->levels_copied
= _mesa_pointer_set_create(mem_ctx
);
1112 _mesa_set_add(level
->levels_copied
, copy_level
);
1114 /* We have a wildcard and it comes from a variable we aren't
1115 * tracking; flag it and we'll know to not shorten this array.
1117 level
->has_external_copy
= true;
1122 level
->max_written
= MAX2(level
->max_written
, max_used
);
1124 level
->max_read
= MAX2(level
->max_read
, max_used
);
1129 src_is_load_deref(nir_src src
, nir_src deref_src
)
1131 nir_intrinsic_instr
*load
= nir_src_as_intrinsic(src
);
1132 if (load
== NULL
|| load
->intrinsic
!= nir_intrinsic_load_deref
)
1135 assert(load
->src
[0].is_ssa
);
1137 return load
->src
[0].ssa
== deref_src
.ssa
;
1140 /* Returns all non-self-referential components of a store instruction. A
1141 * component is self-referential if it comes from the same component of a load
1142 * instruction on the same deref. If the only data in a particular component
1143 * of a variable came directly from that component then it's undefined. The
1144 * only way to get defined data into a component of a variable is for it to
1145 * get written there by something outside or from a different component.
1147 * This is a fairly common pattern in shaders that come from either GLSL IR or
1148 * GLSLang because both glsl_to_nir and GLSLang implement write-masking with
1151 static nir_component_mask_t
1152 get_non_self_referential_store_comps(nir_intrinsic_instr
*store
)
1154 nir_component_mask_t comps
= nir_intrinsic_write_mask(store
);
1156 assert(store
->src
[1].is_ssa
);
1157 nir_instr
*src_instr
= store
->src
[1].ssa
->parent_instr
;
1158 if (src_instr
->type
!= nir_instr_type_alu
)
1161 nir_alu_instr
*src_alu
= nir_instr_as_alu(src_instr
);
1163 if (src_alu
->op
== nir_op_mov
) {
1164 /* If it's just a swizzle of a load from the same deref, discount any
1165 * channels that don't move in the swizzle.
1167 if (src_is_load_deref(src_alu
->src
[0].src
, store
->src
[0])) {
1168 for (unsigned i
= 0; i
< NIR_MAX_VEC_COMPONENTS
; i
++) {
1169 if (src_alu
->src
[0].swizzle
[i
] == i
)
1170 comps
&= ~(1u << i
);
1173 } else if (nir_op_is_vec(src_alu
->op
)) {
1174 /* If it's a vec, discount any channels that are just loads from the
1175 * same deref put in the same spot.
1177 for (unsigned i
= 0; i
< nir_op_infos
[src_alu
->op
].num_inputs
; i
++) {
1178 if (src_is_load_deref(src_alu
->src
[i
].src
, store
->src
[0]) &&
1179 src_alu
->src
[i
].swizzle
[0] == i
)
1180 comps
&= ~(1u << i
);
1188 find_used_components_impl(nir_function_impl
*impl
,
1189 struct hash_table
*var_usage_map
,
1190 nir_variable_mode modes
,
1193 nir_foreach_block(block
, impl
) {
1194 nir_foreach_instr(instr
, block
) {
1195 if (instr
->type
== nir_instr_type_deref
) {
1196 mark_deref_if_complex(nir_instr_as_deref(instr
),
1197 var_usage_map
, modes
, mem_ctx
);
1200 if (instr
->type
!= nir_instr_type_intrinsic
)
1203 nir_intrinsic_instr
*intrin
= nir_instr_as_intrinsic(instr
);
1204 switch (intrin
->intrinsic
) {
1205 case nir_intrinsic_load_deref
:
1206 mark_deref_used(nir_src_as_deref(intrin
->src
[0]),
1207 nir_ssa_def_components_read(&intrin
->dest
.ssa
), 0,
1208 NULL
, var_usage_map
, modes
, mem_ctx
);
1211 case nir_intrinsic_store_deref
:
1212 mark_deref_used(nir_src_as_deref(intrin
->src
[0]),
1213 0, get_non_self_referential_store_comps(intrin
),
1214 NULL
, var_usage_map
, modes
, mem_ctx
);
1217 case nir_intrinsic_copy_deref
: {
1218 /* Just mark everything used for copies. */
1219 nir_deref_instr
*dst
= nir_src_as_deref(intrin
->src
[0]);
1220 nir_deref_instr
*src
= nir_src_as_deref(intrin
->src
[1]);
1221 mark_deref_used(dst
, 0, ~0, src
, var_usage_map
, modes
, mem_ctx
);
1222 mark_deref_used(src
, ~0, 0, dst
, var_usage_map
, modes
, mem_ctx
);
1234 shrink_vec_var_list(struct exec_list
*vars
,
1235 struct hash_table
*var_usage_map
)
1237 /* Initialize the components kept field of each variable. This is the
1238 * AND of the components written and components read. If a component is
1239 * written but never read, it's dead. If it is read but never written,
1240 * then all values read are undefined garbage and we may as well not read
1243 * The same logic applies to the array length. We make the array length
1244 * the minimum needed required length between read and write and plan to
1245 * discard any OOB access. The one exception here is indirect writes
1246 * because we don't know where they will land and we can't shrink an array
1247 * with indirect writes because previously in-bounds writes may become
1248 * out-of-bounds and have undefined behavior.
1250 * Also, if we have a copy that to/from something we can't shrink, we need
1251 * to leave components and array_len of any wildcards alone.
1253 nir_foreach_variable(var
, vars
) {
1254 struct vec_var_usage
*usage
=
1255 get_vec_var_usage(var
, var_usage_map
, false, NULL
);
1259 assert(usage
->comps_kept
== 0);
1260 if (usage
->has_external_copy
|| usage
->has_complex_use
)
1261 usage
->comps_kept
= usage
->all_comps
;
1263 usage
->comps_kept
= usage
->comps_read
& usage
->comps_written
;
1265 for (unsigned i
= 0; i
< usage
->num_levels
; i
++) {
1266 struct array_level_usage
*level
= &usage
->levels
[i
];
1267 assert(level
->array_len
> 0);
1269 if (level
->max_written
== UINT_MAX
|| level
->has_external_copy
||
1270 usage
->has_complex_use
)
1271 continue; /* Can't shrink */
1273 unsigned max_used
= MIN2(level
->max_read
, level
->max_written
);
1274 level
->array_len
= MIN2(max_used
, level
->array_len
- 1) + 1;
1278 /* In order for variable copies to work, we have to have the same data type
1279 * on the source and the destination. In order to satisfy this, we run a
1280 * little fixed-point algorithm to transitively ensure that we get enough
1281 * components and array elements for this to hold for all copies.
1285 fp_progress
= false;
1286 nir_foreach_variable(var
, vars
) {
1287 struct vec_var_usage
*var_usage
=
1288 get_vec_var_usage(var
, var_usage_map
, false, NULL
);
1289 if (!var_usage
|| !var_usage
->vars_copied
)
1292 set_foreach(var_usage
->vars_copied
, copy_entry
) {
1293 struct vec_var_usage
*copy_usage
= (void *)copy_entry
->key
;
1294 if (copy_usage
->comps_kept
!= var_usage
->comps_kept
) {
1295 nir_component_mask_t comps_kept
=
1296 (var_usage
->comps_kept
| copy_usage
->comps_kept
);
1297 var_usage
->comps_kept
= comps_kept
;
1298 copy_usage
->comps_kept
= comps_kept
;
1303 for (unsigned i
= 0; i
< var_usage
->num_levels
; i
++) {
1304 struct array_level_usage
*var_level
= &var_usage
->levels
[i
];
1305 if (!var_level
->levels_copied
)
1308 set_foreach(var_level
->levels_copied
, copy_entry
) {
1309 struct array_level_usage
*copy_level
= (void *)copy_entry
->key
;
1310 if (var_level
->array_len
!= copy_level
->array_len
) {
1311 unsigned array_len
=
1312 MAX2(var_level
->array_len
, copy_level
->array_len
);
1313 var_level
->array_len
= array_len
;
1314 copy_level
->array_len
= array_len
;
1320 } while (fp_progress
);
1322 bool vars_shrunk
= false;
1323 nir_foreach_variable_safe(var
, vars
) {
1324 struct vec_var_usage
*usage
=
1325 get_vec_var_usage(var
, var_usage_map
, false, NULL
);
1329 bool shrunk
= false;
1330 const struct glsl_type
*vec_type
= var
->type
;
1331 for (unsigned i
= 0; i
< usage
->num_levels
; i
++) {
1332 /* If we've reduced the array to zero elements at some level, just
1333 * set comps_kept to 0 and delete the variable.
1335 if (usage
->levels
[i
].array_len
== 0) {
1336 usage
->comps_kept
= 0;
1340 assert(usage
->levels
[i
].array_len
<= glsl_get_length(vec_type
));
1341 if (usage
->levels
[i
].array_len
< glsl_get_length(vec_type
))
1343 vec_type
= glsl_get_array_element(vec_type
);
1345 assert(glsl_type_is_vector_or_scalar(vec_type
));
1347 assert(usage
->comps_kept
== (usage
->comps_kept
& usage
->all_comps
));
1348 if (usage
->comps_kept
!= usage
->all_comps
)
1351 if (usage
->comps_kept
== 0) {
1352 /* This variable is dead, remove it */
1354 exec_node_remove(&var
->node
);
1359 /* This variable doesn't need to be shrunk. Remove it from the
1360 * hash table so later steps will ignore it.
1362 _mesa_hash_table_remove_key(var_usage_map
, var
);
1366 /* Build the new var type */
1367 unsigned new_num_comps
= util_bitcount(usage
->comps_kept
);
1368 const struct glsl_type
*new_type
=
1369 glsl_vector_type(glsl_get_base_type(vec_type
), new_num_comps
);
1370 for (int i
= usage
->num_levels
- 1; i
>= 0; i
--) {
1371 assert(usage
->levels
[i
].array_len
> 0);
1372 /* If the original type was a matrix type, we'd like to keep that so
1373 * we don't convert matrices into arrays.
1375 if (i
== usage
->num_levels
- 1 &&
1376 glsl_type_is_matrix(glsl_without_array(var
->type
)) &&
1377 new_num_comps
> 1 && usage
->levels
[i
].array_len
> 1) {
1378 new_type
= glsl_matrix_type(glsl_get_base_type(new_type
),
1380 usage
->levels
[i
].array_len
);
1382 new_type
= glsl_array_type(new_type
, usage
->levels
[i
].array_len
, 0);
1385 var
->type
= new_type
;
1394 vec_deref_is_oob(nir_deref_instr
*deref
,
1395 struct vec_var_usage
*usage
)
1397 nir_deref_path path
;
1398 nir_deref_path_init(&path
, deref
, NULL
);
1401 for (unsigned i
= 0; i
< usage
->num_levels
; i
++) {
1402 nir_deref_instr
*p
= path
.path
[i
+ 1];
1403 if (p
->deref_type
== nir_deref_type_array_wildcard
)
1406 if (nir_src_is_const(p
->arr
.index
) &&
1407 nir_src_as_uint(p
->arr
.index
) >= usage
->levels
[i
].array_len
) {
1413 nir_deref_path_finish(&path
);
1419 vec_deref_is_dead_or_oob(nir_deref_instr
*deref
,
1420 struct hash_table
*var_usage_map
,
1421 nir_variable_mode modes
)
1423 struct vec_var_usage
*usage
=
1424 get_vec_deref_usage(deref
, var_usage_map
, modes
, false, NULL
);
1428 return usage
->comps_kept
== 0 || vec_deref_is_oob(deref
, usage
);
1432 shrink_vec_var_access_impl(nir_function_impl
*impl
,
1433 struct hash_table
*var_usage_map
,
1434 nir_variable_mode modes
)
1437 nir_builder_init(&b
, impl
);
1439 nir_foreach_block(block
, impl
) {
1440 nir_foreach_instr_safe(instr
, block
) {
1441 switch (instr
->type
) {
1442 case nir_instr_type_deref
: {
1443 nir_deref_instr
*deref
= nir_instr_as_deref(instr
);
1444 if (!(deref
->mode
& modes
))
1447 /* Clean up any dead derefs we find lying around. They may refer
1448 * to variables we've deleted.
1450 if (nir_deref_instr_remove_if_unused(deref
))
1453 /* Update the type in the deref to keep the types consistent as
1454 * you walk down the chain. We don't need to check if this is one
1455 * of the derefs we're shrinking because this is a no-op if it
1456 * isn't. The worst that could happen is that we accidentally fix
1459 if (deref
->deref_type
== nir_deref_type_var
) {
1460 deref
->type
= deref
->var
->type
;
1461 } else if (deref
->deref_type
== nir_deref_type_array
||
1462 deref
->deref_type
== nir_deref_type_array_wildcard
) {
1463 nir_deref_instr
*parent
= nir_deref_instr_parent(deref
);
1464 assert(glsl_type_is_array(parent
->type
) ||
1465 glsl_type_is_matrix(parent
->type
));
1466 deref
->type
= glsl_get_array_element(parent
->type
);
1471 case nir_instr_type_intrinsic
: {
1472 nir_intrinsic_instr
*intrin
= nir_instr_as_intrinsic(instr
);
1474 /* If we have a copy whose source or destination has been deleted
1475 * because we determined the variable was dead, then we just
1476 * delete the copy instruction. If the source variable was dead
1477 * then it was writing undefined garbage anyway and if it's the
1478 * destination variable that's dead then the write isn't needed.
1480 if (intrin
->intrinsic
== nir_intrinsic_copy_deref
) {
1481 nir_deref_instr
*dst
= nir_src_as_deref(intrin
->src
[0]);
1482 nir_deref_instr
*src
= nir_src_as_deref(intrin
->src
[1]);
1483 if (vec_deref_is_dead_or_oob(dst
, var_usage_map
, modes
) ||
1484 vec_deref_is_dead_or_oob(src
, var_usage_map
, modes
)) {
1485 nir_instr_remove(&intrin
->instr
);
1486 nir_deref_instr_remove_if_unused(dst
);
1487 nir_deref_instr_remove_if_unused(src
);
1492 if (intrin
->intrinsic
!= nir_intrinsic_load_deref
&&
1493 intrin
->intrinsic
!= nir_intrinsic_store_deref
)
1496 nir_deref_instr
*deref
= nir_src_as_deref(intrin
->src
[0]);
1497 if (!(deref
->mode
& modes
))
1500 struct vec_var_usage
*usage
=
1501 get_vec_deref_usage(deref
, var_usage_map
, modes
, false, NULL
);
1505 if (usage
->comps_kept
== 0 || vec_deref_is_oob(deref
, usage
)) {
1506 if (intrin
->intrinsic
== nir_intrinsic_load_deref
) {
1508 nir_ssa_undef(&b
, intrin
->dest
.ssa
.num_components
,
1509 intrin
->dest
.ssa
.bit_size
);
1510 nir_ssa_def_rewrite_uses(&intrin
->dest
.ssa
,
1511 nir_src_for_ssa(u
));
1513 nir_instr_remove(&intrin
->instr
);
1514 nir_deref_instr_remove_if_unused(deref
);
1518 /* If we're not dropping any components, there's no need to
1521 if (usage
->comps_kept
== usage
->all_comps
)
1524 if (intrin
->intrinsic
== nir_intrinsic_load_deref
) {
1525 b
.cursor
= nir_after_instr(&intrin
->instr
);
1527 nir_ssa_def
*undef
=
1528 nir_ssa_undef(&b
, 1, intrin
->dest
.ssa
.bit_size
);
1529 nir_ssa_def
*vec_srcs
[NIR_MAX_VEC_COMPONENTS
];
1531 for (unsigned i
= 0; i
< intrin
->num_components
; i
++) {
1532 if (usage
->comps_kept
& (1u << i
))
1533 vec_srcs
[i
] = nir_channel(&b
, &intrin
->dest
.ssa
, c
++);
1535 vec_srcs
[i
] = undef
;
1537 nir_ssa_def
*vec
= nir_vec(&b
, vec_srcs
, intrin
->num_components
);
1539 nir_ssa_def_rewrite_uses_after(&intrin
->dest
.ssa
,
1540 nir_src_for_ssa(vec
),
1543 /* The SSA def is now only used by the swizzle. It's safe to
1544 * shrink the number of components.
1546 assert(list_length(&intrin
->dest
.ssa
.uses
) == c
);
1547 intrin
->num_components
= c
;
1548 intrin
->dest
.ssa
.num_components
= c
;
1550 nir_component_mask_t write_mask
=
1551 nir_intrinsic_write_mask(intrin
);
1553 unsigned swizzle
[NIR_MAX_VEC_COMPONENTS
];
1554 nir_component_mask_t new_write_mask
= 0;
1556 for (unsigned i
= 0; i
< intrin
->num_components
; i
++) {
1557 if (usage
->comps_kept
& (1u << i
)) {
1559 if (write_mask
& (1u << i
))
1560 new_write_mask
|= 1u << c
;
1565 b
.cursor
= nir_before_instr(&intrin
->instr
);
1567 nir_ssa_def
*swizzled
=
1568 nir_swizzle(&b
, intrin
->src
[1].ssa
, swizzle
, c
);
1570 /* Rewrite to use the compacted source */
1571 nir_instr_rewrite_src(&intrin
->instr
, &intrin
->src
[1],
1572 nir_src_for_ssa(swizzled
));
1573 nir_intrinsic_set_write_mask(intrin
, new_write_mask
);
1574 intrin
->num_components
= c
;
1587 function_impl_has_vars_with_modes(nir_function_impl
*impl
,
1588 nir_variable_mode modes
)
1590 nir_shader
*shader
= impl
->function
->shader
;
1592 if ((modes
& nir_var_shader_temp
) && !exec_list_is_empty(&shader
->globals
))
1595 if ((modes
& nir_var_function_temp
) && !exec_list_is_empty(&impl
->locals
))
1601 /** Attempt to shrink arrays of vectors
1603 * This pass looks at variables which contain a vector or an array (possibly
1604 * multiple dimensions) of vectors and attempts to lower to a smaller vector
1605 * or array. If the pass can prove that a component of a vector (or array of
1606 * vectors) is never really used, then that component will be removed.
1607 * Similarly, the pass attempts to shorten arrays based on what elements it
1608 * can prove are never read or never contain valid data.
1611 nir_shrink_vec_array_vars(nir_shader
*shader
, nir_variable_mode modes
)
1613 assert((modes
& (nir_var_shader_temp
| nir_var_function_temp
)) == modes
);
1615 void *mem_ctx
= ralloc_context(NULL
);
1617 struct hash_table
*var_usage_map
=
1618 _mesa_pointer_hash_table_create(mem_ctx
);
1620 bool has_vars_to_shrink
= false;
1621 nir_foreach_function(function
, shader
) {
1622 if (!function
->impl
)
1625 /* Don't even bother crawling the IR if we don't have any variables.
1626 * Given that this pass deletes any unused variables, it's likely that
1627 * we will be in this scenario eventually.
1629 if (function_impl_has_vars_with_modes(function
->impl
, modes
)) {
1630 has_vars_to_shrink
= true;
1631 find_used_components_impl(function
->impl
, var_usage_map
,
1635 if (!has_vars_to_shrink
) {
1636 ralloc_free(mem_ctx
);
1640 bool globals_shrunk
= false;
1641 if (modes
& nir_var_shader_temp
)
1642 globals_shrunk
= shrink_vec_var_list(&shader
->globals
, var_usage_map
);
1644 bool progress
= false;
1645 nir_foreach_function(function
, shader
) {
1646 if (!function
->impl
)
1649 bool locals_shrunk
= false;
1650 if (modes
& nir_var_function_temp
) {
1651 locals_shrunk
= shrink_vec_var_list(&function
->impl
->locals
,
1655 if (globals_shrunk
|| locals_shrunk
) {
1656 shrink_vec_var_access_impl(function
->impl
, var_usage_map
, modes
);
1658 nir_metadata_preserve(function
->impl
, nir_metadata_block_index
|
1659 nir_metadata_dominance
);
1662 nir_metadata_preserve(function
->impl
, nir_metadata_all
);
1666 ralloc_free(mem_ctx
);