test/opt/eliminate_dead_functions_test.cpp

// Copyright (c) 2017 Google Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#include <string>
#include <vector>

#include "gmock/gmock.h"
#include "test/opt/assembly_builder.h"
#include "test/opt/pass_fixture.h"
#include "test/opt/pass_utils.h"

namespace spvtools {
namespace opt {
namespace {

using ::testing::HasSubstr;
using EliminateDeadFunctionsBasicTest = PassTest<::testing::Test>;

TEST_F(EliminateDeadFunctionsBasicTest, BasicDeleteDeadFunction) {
  // The function Dead should be removed because it is never called.
  const std::vector<const char*> common_code = {
      // clang-format off
               "OpCapability Shader",
               "OpMemoryModel Logical GLSL450",
               "OpEntryPoint Fragment %main \"main\"",
               "OpName %main \"main\"",
               "OpName %Live \"Live\"",
       "%void = OpTypeVoid",
          "%7 = OpTypeFunction %void",
       "%main = OpFunction %void None %7",
         "%15 = OpLabel",
         "%16 = OpFunctionCall %void %Live",
         "%17 = OpFunctionCall %void %Live",
               "OpReturn",
               "OpFunctionEnd",
  "%Live = OpFunction %void None %7",
         "%20 = OpLabel",
               "OpReturn",
               "OpFunctionEnd"
      // clang-format on
  };

  const std::vector<const char*> dead_function = {
      // clang-format off
      "%Dead = OpFunction %void None %7",
         "%19 = OpLabel",
               "OpReturn",
               "OpFunctionEnd",
      // clang-format on
  };

  SetAssembleOptions(SPV_TEXT_TO_BINARY_OPTION_PRESERVE_NUMERIC_IDS);
  SinglePassRunAndCheck<EliminateDeadFunctionsPass>(
      JoinAllInsts(Concat(common_code, dead_function)),
      JoinAllInsts(common_code), /* skip_nop = */ true);
}

TEST_F(EliminateDeadFunctionsBasicTest, BasicKeepLiveFunction) {
  // Everything is reachable from an entry point, so no functions should be
  // deleted.
  const std::vector<const char*> text = {
      // clang-format off
               "OpCapability Shader",
               "OpMemoryModel Logical GLSL450",
               "OpEntryPoint Fragment %main \"main\"",
               "OpName %main \"main\"",
               "OpName %Live1 \"Live1\"",
               "OpName %Live2 \"Live2\"",
       "%void = OpTypeVoid",
          "%7 = OpTypeFunction %void",
       "%main = OpFunction %void None %7",
         "%15 = OpLabel",
         "%16 = OpFunctionCall %void %Live2",
         "%17 = OpFunctionCall %void %Live1",
               "OpReturn",
               "OpFunctionEnd",
      "%Live1 = OpFunction %void None %7",
         "%19 = OpLabel",
               "OpReturn",
               "OpFunctionEnd",
      "%Live2 = OpFunction %void None %7",
         "%20 = OpLabel",
               "OpReturn",
               "OpFunctionEnd"
      // clang-format on
  };

  SetAssembleOptions(SPV_TEXT_TO_BINARY_OPTION_PRESERVE_NUMERIC_IDS);
  std::string assembly = JoinAllInsts(text);
  auto result = SinglePassRunAndDisassemble<EliminateDeadFunctionsPass>(
      assembly, /* skip_nop = */ true, /* do_validation = */ false);
  EXPECT_EQ(Pass::Status::SuccessWithoutChange, std::get<1>(result));
  EXPECT_EQ(assembly, std::get<0>(result));
}

TEST_F(EliminateDeadFunctionsBasicTest, BasicKeepExportFunctions) {
  // All functions are reachable.  In particular, ExportedFunc and Constant are
  // reachable because ExportedFunc is exported.  Nothing should be removed.
  const std::vector<const char*> text = {
      // clang-format off
               "OpCapability Shader",
               "OpCapability Linkage",
               "OpMemoryModel Logical GLSL450",
               "OpEntryPoint Fragment %main \"main\"",
               "OpName %main \"main\"",
               "OpName %ExportedFunc \"ExportedFunc\"",
               "OpName %Live \"Live\"",
               "OpDecorate %ExportedFunc LinkageAttributes \"ExportedFunc\" Export",
       "%void = OpTypeVoid",
          "%7 = OpTypeFunction %void",
       "%main = OpFunction %void None %7",
         "%15 = OpLabel",
               "OpReturn",
               "OpFunctionEnd",
"%ExportedFunc = OpFunction %void None %7",
         "%19 = OpLabel",
         "%16 = OpFunctionCall %void %Live",
               "OpReturn",
               "OpFunctionEnd",
  "%Live = OpFunction %void None %7",
         "%20 = OpLabel",
               "OpReturn",
               "OpFunctionEnd"
      // clang-format on
  };

  SetAssembleOptions(SPV_TEXT_TO_BINARY_OPTION_PRESERVE_NUMERIC_IDS);
  std::string assembly = JoinAllInsts(text);
  auto result = SinglePassRunAndDisassemble<EliminateDeadFunctionsPass>(
      assembly, /* skip_nop = */ true, /* do_validation = */ false);
  EXPECT_EQ(Pass::Status::SuccessWithoutChange, std::get<1>(result));
  EXPECT_EQ(assembly, std::get<0>(result));
}

TEST_F(EliminateDeadFunctionsBasicTest, BasicRemoveDecorationsAndNames) {
  // We want to remove the names and decorations associated with results that
  // are removed.  This test will check for that.
  const std::string text = R"(
               OpCapability Shader
               OpMemoryModel Logical GLSL450
               OpEntryPoint Vertex %main "main"
               OpName %main "main"
               OpName %Dead "Dead"
               OpName %x "x"
               OpName %y "y"
               OpName %z "z"
               OpDecorate %x RelaxedPrecision
               OpDecorate %y RelaxedPrecision
               OpDecorate %z RelaxedPrecision
               OpDecorate %6 RelaxedPrecision
               OpDecorate %7 RelaxedPrecision
               OpDecorate %8 RelaxedPrecision
       %void = OpTypeVoid
         %10 = OpTypeFunction %void
      %float = OpTypeFloat 32
%_ptr_Function_float = OpTypePointer Function %float
    %float_1 = OpConstant %float 1
       %main = OpFunction %void None %10
         %14 = OpLabel
               OpReturn
               OpFunctionEnd
       %Dead = OpFunction %void None %10
         %15 = OpLabel
          %x = OpVariable %_ptr_Function_float Function
          %y = OpVariable %_ptr_Function_float Function
          %z = OpVariable %_ptr_Function_float Function
               OpStore %x %float_1
               OpStore %y %float_1
          %6 = OpLoad %float %x
          %7 = OpLoad %float %y
          %8 = OpFAdd %float %6 %7
               OpStore %z %8
               OpReturn
               OpFunctionEnd)";

  const std::string expected_output = R"(OpCapability Shader
OpMemoryModel Logical GLSL450
OpEntryPoint Vertex %main "main"
OpName %main "main"
%void = OpTypeVoid
%10 = OpTypeFunction %void
%float = OpTypeFloat 32
%_ptr_Function_float = OpTypePointer Function %float
%float_1 = OpConstant %float 1
%main = OpFunction %void None %10
%14 = OpLabel
OpReturn
OpFunctionEnd
)";

  SetAssembleOptions(SPV_TEXT_TO_BINARY_OPTION_PRESERVE_NUMERIC_IDS);
  SinglePassRunAndCheck<EliminateDeadFunctionsPass>(text, expected_output,
                                                    /* skip_nop = */ true);
}

}  // namespace
}  // namespace opt
}  // namespace spvtools