2 * Copyright © 2014 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
24 * Connor Abbott (cwabbott0@gmail.com)
31 deref_used_for_not_store(nir_deref_instr
*deref
)
33 nir_foreach_use(src
, &deref
->dest
.ssa
) {
34 switch (src
->parent_instr
->type
) {
35 case nir_instr_type_deref
:
36 if (deref_used_for_not_store(nir_instr_as_deref(src
->parent_instr
)))
40 case nir_instr_type_intrinsic
: {
41 nir_intrinsic_instr
*intrin
=
42 nir_instr_as_intrinsic(src
->parent_instr
);
43 /* The first source of copy and store intrinsics is the deref to
44 * write. Don't record those.
46 if ((intrin
->intrinsic
!= nir_intrinsic_store_deref
&&
47 intrin
->intrinsic
!= nir_intrinsic_copy_deref
) ||
48 src
!= &intrin
->src
[0])
54 /* If it's used by any other instruction type (most likely a texture
55 * or call instruction), consider it used.
65 add_var_use_deref(nir_deref_instr
*deref
, struct set
*live
)
67 if (deref
->deref_type
!= nir_deref_type_var
)
70 /* If it's not a local that never escapes the shader, then any access at
71 * all means we need to keep it alive.
73 assert(deref
->mode
== deref
->var
->data
.mode
);
74 if (!(deref
->mode
& (nir_var_local
| nir_var_global
| nir_var_shared
)) ||
75 deref_used_for_not_store(deref
))
76 _mesa_set_add(live
, deref
->var
);
80 add_var_use_shader(nir_shader
*shader
, struct set
*live
, nir_variable_mode modes
)
82 nir_foreach_function(function
, shader
) {
84 nir_foreach_block(block
, function
->impl
) {
85 nir_foreach_instr(instr
, block
) {
86 if (instr
->type
== nir_instr_type_deref
)
87 add_var_use_deref(nir_instr_as_deref(instr
), live
);
95 remove_dead_var_writes(nir_shader
*shader
, struct set
*live
)
97 nir_foreach_function(function
, shader
) {
101 nir_foreach_block(block
, function
->impl
) {
102 nir_foreach_instr_safe(instr
, block
) {
103 switch (instr
->type
) {
104 case nir_instr_type_deref
: {
105 nir_deref_instr
*deref
= nir_instr_as_deref(instr
);
107 nir_variable_mode parent_mode
;
108 if (deref
->deref_type
== nir_deref_type_var
)
109 parent_mode
= deref
->var
->data
.mode
;
111 parent_mode
= nir_deref_instr_parent(deref
)->mode
;
113 /* If the parent mode is 0, then it references a dead variable.
114 * Flag this deref as dead and remove it.
116 if (parent_mode
== 0) {
118 nir_instr_remove(&deref
->instr
);
123 case nir_instr_type_intrinsic
: {
124 nir_intrinsic_instr
*intrin
= nir_instr_as_intrinsic(instr
);
125 if (intrin
->intrinsic
!= nir_intrinsic_copy_deref
&&
126 intrin
->intrinsic
!= nir_intrinsic_store_deref
)
129 if (nir_src_as_deref(intrin
->src
[0])->mode
== 0)
130 nir_instr_remove(instr
);
135 break; /* Nothing to do */
143 remove_dead_vars(struct exec_list
*var_list
, struct set
*live
)
145 bool progress
= false;
147 foreach_list_typed_safe(nir_variable
, var
, node
, var_list
) {
148 struct set_entry
*entry
= _mesa_set_search(live
, var
);
150 /* Mark this variable as used by setting the mode to 0 */
152 exec_node_remove(&var
->node
);
161 nir_remove_dead_variables(nir_shader
*shader
, nir_variable_mode modes
)
163 bool progress
= false;
165 _mesa_set_create(NULL
, _mesa_hash_pointer
, _mesa_key_pointer_equal
);
167 add_var_use_shader(shader
, live
, modes
);
169 if (modes
& nir_var_uniform
)
170 progress
= remove_dead_vars(&shader
->uniforms
, live
) || progress
;
172 if (modes
& nir_var_shader_in
)
173 progress
= remove_dead_vars(&shader
->inputs
, live
) || progress
;
175 if (modes
& nir_var_shader_out
)
176 progress
= remove_dead_vars(&shader
->outputs
, live
) || progress
;
178 if (modes
& nir_var_global
)
179 progress
= remove_dead_vars(&shader
->globals
, live
) || progress
;
181 if (modes
& nir_var_system_value
)
182 progress
= remove_dead_vars(&shader
->system_values
, live
) || progress
;
184 if (modes
& nir_var_shared
)
185 progress
= remove_dead_vars(&shader
->shared
, live
) || progress
;
187 if (modes
& nir_var_local
) {
188 nir_foreach_function(function
, shader
) {
189 if (function
->impl
) {
190 if (remove_dead_vars(&function
->impl
->locals
, live
))
197 remove_dead_var_writes(shader
, live
);
199 nir_foreach_function(function
, shader
) {
200 if (function
->impl
) {
201 nir_metadata_preserve(function
->impl
, nir_metadata_block_index
|
202 nir_metadata_dominance
);
207 _mesa_set_destroy(live
, NULL
);