1 /*
2 * Copyright © 2021 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 #include "nir.h"
25 #include "nir_builder.h"
26
27 #include "util/set.h"
28 #include "util/macros.h"
29
30 /** @file nir_opt_ray_queries.c
31 *
32 * Remove ray queries that the shader is not using the result of.
33 */
34
35 static void
mark_query_read(struct set * queries,nir_intrinsic_instr * intrin)36 mark_query_read(struct set *queries,
37 nir_intrinsic_instr *intrin)
38 {
39 nir_ssa_def *rq_def = intrin->src[0].ssa;
40
41 nir_variable *query;
42 if (rq_def->parent_instr->type == nir_instr_type_intrinsic) {
43 nir_intrinsic_instr *load_deref =
44 nir_instr_as_intrinsic(rq_def->parent_instr);
45 assert(load_deref->intrinsic == nir_intrinsic_load_deref);
46
47 query = nir_intrinsic_get_var(load_deref, 0);
48 } else if (rq_def->parent_instr->type == nir_instr_type_deref) {
49 query = nir_deref_instr_get_variable(
50 nir_instr_as_deref(rq_def->parent_instr));
51 } else {
52 return;
53 }
54 assert(query);
55
56 _mesa_set_add(queries, query);
57 }
58
59 static void
nir_find_ray_queries_read(struct set * queries,nir_shader * shader)60 nir_find_ray_queries_read(struct set *queries,
61 nir_shader *shader)
62 {
63 nir_foreach_function(function, shader) {
64 nir_function_impl *impl = function->impl;
65
66 if (!impl)
67 continue;
68
69 nir_foreach_block(block, impl) {
70 nir_foreach_instr(instr, block) {
71 if (instr->type != nir_instr_type_intrinsic)
72 continue;
73
74 nir_intrinsic_instr *intrin = nir_instr_as_intrinsic(instr);
75 switch (intrin->intrinsic) {
76 case nir_intrinsic_rq_proceed:
77 if (list_length(&intrin->dest.ssa.uses) > 0 ||
78 list_length(&intrin->dest.ssa.if_uses) > 0)
79 mark_query_read(queries, intrin);
80 break;
81 case nir_intrinsic_rq_load:
82 mark_query_read(queries, intrin);
83 break;
84 default:
85 break;
86 }
87 }
88 }
89 }
90 }
91
92 static bool
nir_replace_unread_queries_instr(nir_builder * b,nir_instr * instr,void * data)93 nir_replace_unread_queries_instr(nir_builder *b, nir_instr *instr, void *data)
94 {
95 struct set *queries = data;
96
97 if (instr->type != nir_instr_type_intrinsic)
98 return false;
99
100 nir_intrinsic_instr *intrin = nir_instr_as_intrinsic(instr);
101 switch (intrin->intrinsic) {
102 case nir_intrinsic_rq_initialize:
103 case nir_intrinsic_rq_terminate:
104 case nir_intrinsic_rq_generate_intersection:
105 case nir_intrinsic_rq_confirm_intersection:
106 break;
107 case nir_intrinsic_rq_proceed:
108 break;
109 default:
110 return false;
111 }
112
113 nir_variable *query = nir_intrinsic_get_var(intrin, 0);
114 assert(query);
115
116 struct set_entry *entry = _mesa_set_search(queries, query);
117 if (entry)
118 return false;
119
120 if (intrin->intrinsic == nir_intrinsic_rq_load) {
121 assert(list_is_empty(&intrin->dest.ssa.uses));
122 assert(list_is_empty(&intrin->dest.ssa.if_uses));
123 }
124
125 nir_instr_remove(instr);
126
127 return true;
128 }
129
130 bool
nir_opt_ray_queries(nir_shader * shader)131 nir_opt_ray_queries(nir_shader *shader)
132 {
133 struct set *read_queries = _mesa_pointer_set_create(NULL);
134 nir_find_ray_queries_read(read_queries, shader);
135
136 bool progress =
137 nir_shader_instructions_pass(shader,
138 nir_replace_unread_queries_instr,
139 nir_metadata_block_index |
140 nir_metadata_dominance,
141 read_queries);
142
143 /* Update the number of queries if some have been removed. */
144 if (progress) {
145 nir_remove_dead_derefs(shader);
146 nir_remove_dead_variables(shader,
147 nir_var_shader_temp | nir_var_function_temp,
148 NULL);
149 nir_shader_gather_info(shader, nir_shader_get_entrypoint(shader));
150 }
151
152 _mesa_set_destroy(read_queries, NULL);
153
154 return progress;
155 }
156