1 /*
2 * Copyright © 2017 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 /**
28 * \file nir_opt_intrinsics.c
29 */
30
31 static bool
src_is_single_use_shuffle(nir_src src,nir_ssa_def ** data,nir_ssa_def ** index)32 src_is_single_use_shuffle(nir_src src, nir_ssa_def **data, nir_ssa_def **index)
33 {
34 nir_intrinsic_instr *shuffle = nir_src_as_intrinsic(src);
35 if (shuffle == NULL || shuffle->intrinsic != nir_intrinsic_shuffle)
36 return false;
37
38 /* This is only called when src is part of an ALU op so requiring no if
39 * uses is reasonable. If we ever want to use this from an if statement,
40 * we can change it then.
41 */
42 if (!list_is_empty(&shuffle->dest.ssa.if_uses) ||
43 !list_is_singular(&shuffle->dest.ssa.uses))
44 return false;
45
46 assert(shuffle->src[0].is_ssa);
47 assert(shuffle->src[1].is_ssa);
48
49 *data = shuffle->src[0].ssa;
50 *index = shuffle->src[1].ssa;
51
52 return true;
53 }
54
55 static nir_ssa_def *
try_opt_bcsel_of_shuffle(nir_builder * b,nir_alu_instr * alu)56 try_opt_bcsel_of_shuffle(nir_builder *b, nir_alu_instr *alu)
57 {
58 assert(alu->op == nir_op_bcsel);
59
60 if (!nir_alu_src_is_trivial_ssa(alu, 0))
61 return NULL;
62
63 nir_ssa_def *data1, *index1;
64 if (!nir_alu_src_is_trivial_ssa(alu, 1) ||
65 !src_is_single_use_shuffle(alu->src[1].src, &data1, &index1))
66 return NULL;
67
68 nir_ssa_def *data2, *index2;
69 if (!nir_alu_src_is_trivial_ssa(alu, 2) ||
70 !src_is_single_use_shuffle(alu->src[2].src, &data2, &index2))
71 return NULL;
72
73 if (data1 != data2)
74 return NULL;
75
76 nir_ssa_def *index = nir_bcsel(b, alu->src[0].src.ssa, index1, index2);
77 nir_intrinsic_instr *shuffle =
78 nir_intrinsic_instr_create(b->shader, nir_intrinsic_shuffle);
79 shuffle->src[0] = nir_src_for_ssa(index);
80 shuffle->src[1] = nir_src_for_ssa(data1);
81 shuffle->num_components = alu->dest.dest.ssa.num_components;
82 nir_ssa_dest_init(&shuffle->instr, &shuffle->dest,
83 alu->dest.dest.ssa.num_components,
84 alu->dest.dest.ssa.bit_size, NULL);
85 nir_builder_instr_insert(b, &shuffle->instr);
86
87 return &shuffle->dest.ssa;
88 }
89
90 static bool
opt_intrinsics_alu(nir_builder * b,nir_alu_instr * alu)91 opt_intrinsics_alu(nir_builder *b, nir_alu_instr *alu)
92 {
93 nir_ssa_def *replacement = NULL;
94
95 switch (alu->op) {
96 case nir_op_bcsel:
97 replacement = try_opt_bcsel_of_shuffle(b, alu);
98 break;
99
100 default:
101 break;
102 }
103
104 if (replacement) {
105 nir_ssa_def_rewrite_uses(&alu->dest.dest.ssa,
106 nir_src_for_ssa(replacement));
107 nir_instr_remove(&alu->instr);
108 return true;
109 } else {
110 return false;
111 }
112 }
113
114 static bool
opt_intrinsics_intrin(nir_builder * b,nir_intrinsic_instr * intrin,const struct nir_shader_compiler_options * options)115 opt_intrinsics_intrin(nir_builder *b, nir_intrinsic_instr *intrin,
116 const struct nir_shader_compiler_options *options)
117 {
118 switch (intrin->intrinsic) {
119 case nir_intrinsic_load_sample_mask_in: {
120 /* Transform:
121 * gl_SampleMaskIn == 0 ---> gl_HelperInvocation
122 * gl_SampleMaskIn != 0 ---> !gl_HelperInvocation
123 */
124 if (!options->optimize_sample_mask_in)
125 return false;
126
127 bool progress = false;
128 nir_foreach_use_safe(use_src, &intrin->dest.ssa) {
129 if (use_src->parent_instr->type == nir_instr_type_alu) {
130 nir_alu_instr *alu = nir_instr_as_alu(use_src->parent_instr);
131
132 if (alu->op == nir_op_ieq ||
133 alu->op == nir_op_ine) {
134 /* Check for 0 in either operand. */
135 nir_const_value *const_val =
136 nir_src_as_const_value(alu->src[0].src);
137 if (!const_val)
138 const_val = nir_src_as_const_value(alu->src[1].src);
139 if (!const_val || const_val->i32 != 0)
140 continue;
141
142 nir_ssa_def *new_expr = nir_load_helper_invocation(b, 1);
143
144 if (alu->op == nir_op_ine)
145 new_expr = nir_inot(b, new_expr);
146
147 nir_ssa_def_rewrite_uses(&alu->dest.dest.ssa,
148 nir_src_for_ssa(new_expr));
149 nir_instr_remove(&alu->instr);
150 progress = true;
151 }
152 }
153 }
154 return progress;
155 }
156
157 default:
158 return false;
159 }
160 }
161
162 static bool
opt_intrinsics_impl(nir_function_impl * impl,const struct nir_shader_compiler_options * options)163 opt_intrinsics_impl(nir_function_impl *impl,
164 const struct nir_shader_compiler_options *options)
165 {
166 nir_builder b;
167 nir_builder_init(&b, impl);
168 bool progress = false;
169
170 nir_foreach_block(block, impl) {
171 nir_foreach_instr_safe(instr, block) {
172 b.cursor = nir_before_instr(instr);
173
174 switch (instr->type) {
175 case nir_instr_type_alu:
176 if (opt_intrinsics_alu(&b, nir_instr_as_alu(instr)))
177 progress = true;
178 break;
179
180 case nir_instr_type_intrinsic:
181 if (opt_intrinsics_intrin(&b, nir_instr_as_intrinsic(instr),
182 options))
183 progress = true;
184 break;
185
186 default:
187 break;
188 }
189 }
190 }
191
192 return progress;
193 }
194
195 bool
nir_opt_intrinsics(nir_shader * shader)196 nir_opt_intrinsics(nir_shader *shader)
197 {
198 bool progress = false;
199
200 nir_foreach_function(function, shader) {
201 if (!function->impl)
202 continue;
203
204 if (opt_intrinsics_impl(function->impl, shader->options)) {
205 progress = true;
206 nir_metadata_preserve(function->impl, nir_metadata_block_index |
207 nir_metadata_dominance);
208 } else {
209 nir_metadata_preserve(function->impl, nir_metadata_all);
210 }
211 }
212
213 return progress;
214 }
215