src/intel/compiler/test_vec4_dead_code_eliminate.cpp

   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
  28 using namespace brw;
  29
  30 class dead_code_eliminate_test : public ::testing::Test {
  31    virtual void SetUp();
  32
  33 public:
  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
  42 class dead_code_eliminate_vec4_visitor : public vec4_visitor
  43 {
  44 public:
  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
  54 protected:
  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
  87 void 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
 103 static void
 104 dead_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
 122 TEST_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 }