1/*
2 * Copyright © 2020 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
21 * DEALINGS IN THE SOFTWARE.
22 */
23#include <gtest/gtest.h>
24#include "nir.h"
25#include "nir_builder.h"
26
27class nir_opt_if_test : public ::testing::Test {
28protected:
29   nir_opt_if_test();
30   ~nir_opt_if_test();
31
32   nir_builder bld;
33
34   nir_ssa_def *in_def;
35   nir_variable *out_var;
36};
37
38nir_opt_if_test::nir_opt_if_test()
39{
40   glsl_type_singleton_init_or_ref();
41
42   static const nir_shader_compiler_options options = { };
43   bld = nir_builder_init_simple_shader(MESA_SHADER_VERTEX, &options, "if test");
44
45   nir_variable *var = nir_variable_create(bld.shader, nir_var_shader_in, glsl_int_type(), "in");
46   in_def = nir_load_var(&bld, var);
47
48   out_var = nir_variable_create(bld.shader, nir_var_shader_out, glsl_int_type(), "out");
49}
50
51nir_opt_if_test::~nir_opt_if_test()
52{
53   ralloc_free(bld.shader);
54   glsl_type_singleton_decref();
55}
56
57TEST_F(nir_opt_if_test, opt_if_simplification)
58{
59   /* Tests that opt_if_simplification correctly optimizes a simple case:
60    *
61    * vec1 1 ssa_2 = ieq ssa_0, ssa_1
62    * if ssa_2 {
63    *    block block_2:
64    * } else {
65    *    block block_3:
66    *    do_work()
67    * }
68    */
69
70   nir_ssa_def *one = nir_imm_int(&bld, 1);
71
72   nir_ssa_def *cmp_result = nir_ieq(&bld, in_def, one);
73   nir_if *nif = nir_push_if(&bld, cmp_result);
74
75   nir_push_else(&bld, NULL);
76
77   // do_work
78   nir_store_var(&bld, out_var, one, 1);
79
80   nir_pop_if(&bld, NULL);
81
82   ASSERT_TRUE(nir_opt_if(bld.shader, nir_opt_if_optimize_phi_true_false));
83
84   nir_validate_shader(bld.shader, NULL);
85
86   ASSERT_TRUE(!exec_list_is_empty((&nir_if_first_then_block(nif)->instr_list)));
87   ASSERT_TRUE(exec_list_is_empty((&nir_if_first_else_block(nif)->instr_list)));
88}
89
90TEST_F(nir_opt_if_test, opt_if_simplification_single_source_phi_after_if)
91{
92   /* Tests that opt_if_simplification correctly handles single-source
93    * phis after the if.
94    *
95    * vec1 1 ssa_2 = ieq ssa_0, ssa_1
96    * if ssa_2 {
97    *    block block_2:
98    * } else {
99    *    block block_3:
100    *    do_work()
101    *    return
102    * }
103    * block block_4:
104    * vec1 32 ssa_3 = phi block_2: ssa_0
105    */
106
107   nir_ssa_def *one = nir_imm_int(&bld, 1);
108
109   nir_ssa_def *cmp_result = nir_ieq(&bld, in_def, one);
110   nir_if *nif = nir_push_if(&bld, cmp_result);
111
112   nir_push_else(&bld, NULL);
113
114   // do_work
115   nir_store_var(&bld, out_var, one, 1);
116
117   nir_jump_instr *jump = nir_jump_instr_create(bld.shader, nir_jump_return);
118   nir_builder_instr_insert(&bld, &jump->instr);
119
120   nir_pop_if(&bld, NULL);
121
122   nir_block *then_block = nir_if_last_then_block(nif);
123
124   nir_phi_instr *const phi = nir_phi_instr_create(bld.shader);
125
126   nir_phi_instr_add_src(phi, then_block, nir_src_for_ssa(one));
127
128   nir_ssa_dest_init(&phi->instr, &phi->dest,
129                     one->num_components, one->bit_size, NULL);
130
131   nir_builder_instr_insert(&bld, &phi->instr);
132
133   ASSERT_TRUE(nir_opt_if(bld.shader, nir_opt_if_optimize_phi_true_false));
134
135   nir_validate_shader(bld.shader, NULL);
136
137   ASSERT_TRUE(nir_block_ends_in_jump(nir_if_last_then_block(nif)));
138   ASSERT_TRUE(exec_list_is_empty((&nir_if_first_else_block(nif)->instr_list)));
139}
140
141TEST_F(nir_opt_if_test, opt_if_alu_of_phi_progress)
142{
143   nir_ssa_def *two = nir_imm_int(&bld, 2);
144   nir_ssa_def *x = nir_imm_int(&bld, 0);
145
146   nir_phi_instr *phi = nir_phi_instr_create(bld.shader);
147
148   nir_loop *loop = nir_push_loop(&bld);
149   {
150      nir_ssa_dest_init(&phi->instr, &phi->dest,
151                        x->num_components, x->bit_size, NULL);
152
153      nir_phi_instr_add_src(phi, x->parent_instr->block, nir_src_for_ssa(x));
154
155      nir_ssa_def *y = nir_iadd(&bld, &phi->dest.ssa, two);
156      nir_store_var(&bld, out_var,
157                    nir_imul(&bld, &phi->dest.ssa, two), 1);
158
159      nir_phi_instr_add_src(phi, nir_cursor_current_block(bld.cursor), nir_src_for_ssa(y));
160   }
161   nir_pop_loop(&bld, loop);
162
163   bld.cursor = nir_before_block(nir_loop_first_block(loop));
164   nir_builder_instr_insert(&bld, &phi->instr);
165
166   nir_validate_shader(bld.shader, "input");
167
168   bool progress;
169
170   int progress_count = 0;
171   for (int i = 0; i < 10; i++) {
172      progress = nir_opt_if(bld.shader, nir_opt_if_optimize_phi_true_false);
173      if (progress)
174         progress_count++;
175      else
176         break;
177      nir_opt_constant_folding(bld.shader);
178   }
179
180   EXPECT_LE(progress_count, 2);
181   ASSERT_FALSE(progress);
182}
183