1/*
2 * Copyright © 2018 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 <gtest/gtest.h>
25#include "brw_vec4.h"
26#include "program/program.h"
27
28using namespace brw;
29
30class dead_code_eliminate_test : public ::testing::Test {
31   virtual void SetUp();
32
33public:
34   struct brw_compiler *compiler;
35   struct gen_device_info *devinfo;
36   struct gl_context *ctx;
37   struct gl_shader_program *shader_prog;
38   struct brw_vue_prog_data *prog_data;
39   vec4_visitor *v;
40};
41
42class dead_code_eliminate_vec4_visitor : public vec4_visitor
43{
44public:
45   dead_code_eliminate_vec4_visitor(struct brw_compiler *compiler,
46                                 nir_shader *shader,
47                                 struct brw_vue_prog_data *prog_data)
48      : vec4_visitor(compiler, NULL, NULL, prog_data, shader, NULL,
49                     false /* no_spills */, -1)
50   {
51      prog_data->dispatch_mode = DISPATCH_MODE_4X2_DUAL_OBJECT;
52   }
53
54protected:
55   virtual dst_reg *make_reg_for_system_value(int /* location */)
56   {
57      unreachable("Not reached");
58   }
59
60   virtual void setup_payload()
61   {
62      unreachable("Not reached");
63   }
64
65   virtual void emit_prolog()
66   {
67      unreachable("Not reached");
68   }
69
70   virtual void emit_thread_end()
71   {
72      unreachable("Not reached");
73   }
74
75   virtual void emit_urb_write_header(int /* mrf */)
76   {
77      unreachable("Not reached");
78   }
79
80   virtual vec4_instruction *emit_urb_write_opcode(bool /* complete */)
81   {
82      unreachable("Not reached");
83   }
84};
85
86
87void dead_code_eliminate_test::SetUp()
88{
89   ctx = (struct gl_context *)calloc(1, sizeof(*ctx));
90   compiler = (struct brw_compiler *)calloc(1, sizeof(*compiler));
91   devinfo = (struct gen_device_info *)calloc(1, sizeof(*devinfo));
92   prog_data = (struct brw_vue_prog_data *)calloc(1, sizeof(*prog_data));
93   compiler->devinfo = devinfo;
94
95   nir_shader *shader =
96      nir_shader_create(NULL, MESA_SHADER_VERTEX, NULL, NULL);
97
98   v = new dead_code_eliminate_vec4_visitor(compiler, shader, prog_data);
99
100   devinfo->gen = 4;
101}
102
103static void
104dead_code_eliminate(vec4_visitor *v)
105{
106   bool print = false;
107
108   if (print) {
109      fprintf(stderr, "instructions before:\n");
110      v->dump_instructions();
111   }
112
113   v->calculate_cfg();
114   v->dead_code_eliminate();
115
116   if (print) {
117      fprintf(stderr, "instructions after:\n");
118      v->dump_instructions();
119   }
120}
121
122TEST_F(dead_code_eliminate_test, some_dead_channels_all_flags_used)
123{
124   const vec4_builder bld = vec4_builder(v).at_end();
125   src_reg r1 = src_reg(v, glsl_type::vec4_type);
126   src_reg r2 = src_reg(v, glsl_type::vec4_type);
127   src_reg r3 = src_reg(v, glsl_type::vec4_type);
128   src_reg r4 = src_reg(v, glsl_type::vec4_type);
129   src_reg r5 = src_reg(v, glsl_type::vec4_type);
130   src_reg r6 = src_reg(v, glsl_type::vec4_type);
131
132   /* Sequence like the following should not be modified by DCE.
133    *
134    *     cmp.l.f0(8)     g4<1>F         g2<4,4,1>.wF   g1<4,4,1>.xF
135    *     mov(8)          g5<1>.xF       g4<4,4,1>.xF
136    *     (+f0.x) sel(8)  g6<1>UD        g3<4>UD        g6<4>UD
137    */
138   vec4_instruction *test_cmp =
139      bld.CMP(dst_reg(r4), r2, r1, BRW_CONDITIONAL_L);
140
141   test_cmp->src[0].swizzle = BRW_SWIZZLE_WWWW;
142   test_cmp->src[1].swizzle = BRW_SWIZZLE_XXXX;
143
144   vec4_instruction *test_mov =
145      bld.MOV(dst_reg(r5), r4);
146
147   test_mov->dst.writemask = WRITEMASK_X;
148   test_mov->src[0].swizzle = BRW_SWIZZLE_XXXX;
149
150   vec4_instruction *test_sel =
151      bld.SEL(dst_reg(r6), r3, r6);
152
153   set_predicate(BRW_PREDICATE_NORMAL, test_sel);
154
155   /* The scratch write is here just to make r5 and r6 be live so that the
156    * whole program doesn't get eliminated by DCE.
157    */
158   v->emit(v->SCRATCH_WRITE(dst_reg(r4), r6, r5));
159
160   dead_code_eliminate(v);
161
162   EXPECT_EQ(test_cmp->dst.writemask, WRITEMASK_XYZW);
163}
164