SPIRV-Tools/test/reduce/simple_conditional_branch_to_branch_test.cpp
Paul Thomson 3335c61147
reduce: Add two branch reduction passes (#2507)
* Fix #2320. `conditional_branch_to_simple_conditional_branch` reduction pass changes conditional branches so both targets point to the same block id (creating a "simple" conditional branch).
* Fix #2501. `simple_conditional_branch_to_branch` reduction pass changes "simple" conditional branches to branches. 
* Fix #2503. `conditional_branch_to_simple_conditional_branch` proper handling of back-edges.
2019-04-15 19:54:36 +01:00

487 lines
14 KiB
C++

// Copyright (c) 2019 Google LLC
//
// 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 "source/reduce/simple_conditional_branch_to_branch_opportunity_finder.h"
#include "source/opt/build_module.h"
#include "source/reduce/reduction_opportunity.h"
#include "source/reduce/reduction_pass.h"
#include "test/reduce/reduce_test_util.h"
namespace spvtools {
namespace reduce {
namespace {
const spv_target_env kEnv = SPV_ENV_UNIVERSAL_1_3;
TEST(SimpleConditionalBranchToBranchTest, Diamond) {
// A test with the following structure.
//
// selection header
// OpBranchConditional
// ||
// b b
// | |
// selection merge
//
// The conditional branch cannot be simplified because selection headers
// cannot end with OpBranch.
std::string shader = R"(
OpCapability Shader
%1 = OpExtInstImport "GLSL.std.450"
OpMemoryModel Logical GLSL450
OpEntryPoint Fragment %2 "main"
OpExecutionMode %2 OriginUpperLeft
OpSource ESSL 310
OpName %2 "main"
%3 = OpTypeVoid
%4 = OpTypeFunction %3
%5 = OpTypeInt 32 1
%6 = OpTypePointer Function %5
%7 = OpTypeBool
%8 = OpConstantTrue %7
%2 = OpFunction %3 None %4
%9 = OpLabel
OpBranch %10
%10 = OpLabel
OpSelectionMerge %11 None
OpBranchConditional %8 %12 %12
%12 = OpLabel
OpBranch %11
%13 = OpLabel
OpBranch %11
%11 = OpLabel
OpReturn
OpFunctionEnd
)";
auto context = BuildModule(kEnv, nullptr, shader, kReduceAssembleOption);
CheckValid(kEnv, context.get());
auto ops = SimpleConditionalBranchToBranchOpportunityFinder()
.GetAvailableOpportunities(context.get());
ASSERT_EQ(0, ops.size());
}
TEST(SimpleConditionalBranchToBranchTest, DiamondNoSelection) {
// A test with the following structure.
//
// OpBranchConditional
// ||
// b b
// | /
// b
//
// The conditional branch can be simplified.
std::string shader = R"(
OpCapability Shader
%1 = OpExtInstImport "GLSL.std.450"
OpMemoryModel Logical GLSL450
OpEntryPoint Fragment %2 "main"
OpExecutionMode %2 OriginUpperLeft
OpSource ESSL 310
OpName %2 "main"
%3 = OpTypeVoid
%4 = OpTypeFunction %3
%5 = OpTypeInt 32 1
%6 = OpTypePointer Function %5
%7 = OpTypeBool
%8 = OpConstantTrue %7
%2 = OpFunction %3 None %4
%9 = OpLabel
OpBranch %10
%10 = OpLabel
OpBranchConditional %8 %12 %12
%12 = OpLabel
OpBranch %11
%13 = OpLabel
OpBranch %11
%11 = OpLabel
OpReturn
OpFunctionEnd
)";
auto context = BuildModule(kEnv, nullptr, shader, kReduceAssembleOption);
CheckValid(kEnv, context.get());
auto ops = SimpleConditionalBranchToBranchOpportunityFinder()
.GetAvailableOpportunities(context.get());
ASSERT_EQ(1, ops.size());
ASSERT_TRUE(ops[0]->PreconditionHolds());
ops[0]->TryToApply();
CheckValid(kEnv, context.get());
std::string after = R"(
OpCapability Shader
%1 = OpExtInstImport "GLSL.std.450"
OpMemoryModel Logical GLSL450
OpEntryPoint Fragment %2 "main"
OpExecutionMode %2 OriginUpperLeft
OpSource ESSL 310
OpName %2 "main"
%3 = OpTypeVoid
%4 = OpTypeFunction %3
%5 = OpTypeInt 32 1
%6 = OpTypePointer Function %5
%7 = OpTypeBool
%8 = OpConstantTrue %7
%2 = OpFunction %3 None %4
%9 = OpLabel
OpBranch %10
%10 = OpLabel
OpBranch %12
%12 = OpLabel
OpBranch %11
%13 = OpLabel
OpBranch %11
%11 = OpLabel
OpReturn
OpFunctionEnd
)";
CheckEqual(kEnv, after, context.get());
ops = SimpleConditionalBranchToBranchOpportunityFinder()
.GetAvailableOpportunities(context.get());
ASSERT_EQ(0, ops.size());
}
TEST(SimpleConditionalBranchToBranchTest, ConditionalBranchesButNotSimple) {
// A test with the following structure.
//
// selection header
// OpBranchConditional
// | |
// b OpBranchConditional
// | | |
// | b |
// | | |
// selection merge
//
// None of the conditional branches can be simplified; the first is not simple
// AND part of a selection header; the second is just not simple (where
// "simple" means it only has one target).
std::string shader = R"(
OpCapability Shader
%1 = OpExtInstImport "GLSL.std.450"
OpMemoryModel Logical GLSL450
OpEntryPoint Fragment %2 "main"
OpExecutionMode %2 OriginUpperLeft
OpSource ESSL 310
OpName %2 "main"
%3 = OpTypeVoid
%4 = OpTypeFunction %3
%5 = OpTypeInt 32 1
%6 = OpTypePointer Function %5
%7 = OpTypeBool
%8 = OpConstantTrue %7
%2 = OpFunction %3 None %4
%9 = OpLabel
OpBranch %10
%10 = OpLabel
OpSelectionMerge %11 None
OpBranchConditional %8 %12 %13
%12 = OpLabel
OpBranch %11
%13 = OpLabel
OpBranchConditional %8 %14 %11
%14 = OpLabel
OpBranch %11
%11 = OpLabel
OpReturn
OpFunctionEnd
)";
auto context = BuildModule(kEnv, nullptr, shader, kReduceAssembleOption);
CheckValid(kEnv, context.get());
auto ops = SimpleConditionalBranchToBranchOpportunityFinder()
.GetAvailableOpportunities(context.get());
ASSERT_EQ(0, ops.size());
}
TEST(SimpleConditionalBranchToBranchTest, SimplifyBackEdge) {
// A test with the following structure. The loop has a continue construct that
// ends with OpBranchConditional. The OpBranchConditional can be simplified.
//
// loop header
// |
// loop continue target and back-edge block
// OpBranchConditional
// ||
// loop merge (to loop header^)
std::string shader = R"(
OpCapability Shader
%1 = OpExtInstImport "GLSL.std.450"
OpMemoryModel Logical GLSL450
OpEntryPoint Fragment %2 "main"
OpExecutionMode %2 OriginUpperLeft
OpSource ESSL 310
OpName %2 "main"
%3 = OpTypeVoid
%4 = OpTypeFunction %3
%5 = OpTypeInt 32 1
%6 = OpTypePointer Function %5
%7 = OpTypeBool
%8 = OpConstantTrue %7
%2 = OpFunction %3 None %4
%9 = OpLabel
OpBranch %10
%10 = OpLabel
OpLoopMerge %11 %12 None
OpBranch %12
%12 = OpLabel
OpBranchConditional %8 %10 %10
%11 = OpLabel
OpReturn
OpFunctionEnd
)";
const auto context =
BuildModule(kEnv, nullptr, shader, kReduceAssembleOption);
CheckValid(kEnv, context.get());
auto ops = SimpleConditionalBranchToBranchOpportunityFinder()
.GetAvailableOpportunities(context.get());
ASSERT_EQ(1, ops.size());
ASSERT_TRUE(ops[0]->PreconditionHolds());
ops[0]->TryToApply();
CheckValid(kEnv, context.get());
std::string after = R"(
OpCapability Shader
%1 = OpExtInstImport "GLSL.std.450"
OpMemoryModel Logical GLSL450
OpEntryPoint Fragment %2 "main"
OpExecutionMode %2 OriginUpperLeft
OpSource ESSL 310
OpName %2 "main"
%3 = OpTypeVoid
%4 = OpTypeFunction %3
%5 = OpTypeInt 32 1
%6 = OpTypePointer Function %5
%7 = OpTypeBool
%8 = OpConstantTrue %7
%2 = OpFunction %3 None %4
%9 = OpLabel
OpBranch %10
%10 = OpLabel
OpLoopMerge %11 %12 None
OpBranch %12
%12 = OpLabel
OpBranch %10
%11 = OpLabel
OpReturn
OpFunctionEnd
)";
CheckEqual(kEnv, after, context.get());
ops = SimpleConditionalBranchToBranchOpportunityFinder()
.GetAvailableOpportunities(context.get());
ASSERT_EQ(0, ops.size());
}
TEST(SimpleConditionalBranchToBranchTest,
DontRemoveBackEdgeCombinedHeaderContinue) {
// A test with the following structure.
//
// loop header and continue target and back-edge block
// OpBranchConditional
// ||
// loop merge (to loop header^)
//
// The conditional branch can be simplified.
std::string shader = R"(
OpCapability Shader
%1 = OpExtInstImport "GLSL.std.450"
OpMemoryModel Logical GLSL450
OpEntryPoint Fragment %2 "main"
OpExecutionMode %2 OriginUpperLeft
OpSource ESSL 310
OpName %2 "main"
%3 = OpTypeVoid
%4 = OpTypeFunction %3
%5 = OpTypeInt 32 1
%6 = OpTypePointer Function %5
%7 = OpTypeBool
%8 = OpConstantTrue %7
%2 = OpFunction %3 None %4
%9 = OpLabel
OpBranch %10
%10 = OpLabel
OpLoopMerge %11 %10 None
OpBranchConditional %8 %10 %10
%11 = OpLabel
OpReturn
OpFunctionEnd
)";
const auto context =
BuildModule(kEnv, nullptr, shader, kReduceAssembleOption);
CheckValid(kEnv, context.get());
auto ops = SimpleConditionalBranchToBranchOpportunityFinder()
.GetAvailableOpportunities(context.get());
ASSERT_EQ(1, ops.size());
ASSERT_TRUE(ops[0]->PreconditionHolds());
ops[0]->TryToApply();
CheckValid(kEnv, context.get());
std::string after = R"(
OpCapability Shader
%1 = OpExtInstImport "GLSL.std.450"
OpMemoryModel Logical GLSL450
OpEntryPoint Fragment %2 "main"
OpExecutionMode %2 OriginUpperLeft
OpSource ESSL 310
OpName %2 "main"
%3 = OpTypeVoid
%4 = OpTypeFunction %3
%5 = OpTypeInt 32 1
%6 = OpTypePointer Function %5
%7 = OpTypeBool
%8 = OpConstantTrue %7
%2 = OpFunction %3 None %4
%9 = OpLabel
OpBranch %10
%10 = OpLabel
OpLoopMerge %11 %10 None
OpBranch %10
%11 = OpLabel
OpReturn
OpFunctionEnd
)";
CheckEqual(kEnv, after, context.get());
ops = SimpleConditionalBranchToBranchOpportunityFinder()
.GetAvailableOpportunities(context.get());
ASSERT_EQ(0, ops.size());
}
TEST(SimpleConditionalBranchToBranchTest, BackEdgeUnreachable) {
// A test with the following structure. I.e. a loop with an unreachable
// continue construct that ends with OpBranchConditional.
//
// loop header
// |
// | loop continue target (unreachable)
// | |
// | back-edge block (unreachable)
// | OpBranchConditional
// | ||
// loop merge (to loop header^)
//
// The conditional branch can be simplified.
std::string shader = R"(
OpCapability Shader
%1 = OpExtInstImport "GLSL.std.450"
OpMemoryModel Logical GLSL450
OpEntryPoint Fragment %2 "main"
OpExecutionMode %2 OriginUpperLeft
OpSource ESSL 310
OpName %2 "main"
%3 = OpTypeVoid
%4 = OpTypeFunction %3
%5 = OpTypeInt 32 1
%6 = OpTypePointer Function %5
%7 = OpTypeBool
%8 = OpConstantTrue %7
%2 = OpFunction %3 None %4
%9 = OpLabel
OpBranch %10
%10 = OpLabel
OpLoopMerge %11 %12 None
OpBranch %11
%12 = OpLabel
OpBranch %13
%13 = OpLabel
OpBranchConditional %8 %10 %10
%11 = OpLabel
OpReturn
OpFunctionEnd
)";
const auto context =
BuildModule(kEnv, nullptr, shader, kReduceAssembleOption);
CheckValid(kEnv, context.get());
auto ops = SimpleConditionalBranchToBranchOpportunityFinder()
.GetAvailableOpportunities(context.get());
ASSERT_EQ(1, ops.size());
ASSERT_TRUE(ops[0]->PreconditionHolds());
ops[0]->TryToApply();
CheckValid(kEnv, context.get());
std::string after = R"(
OpCapability Shader
%1 = OpExtInstImport "GLSL.std.450"
OpMemoryModel Logical GLSL450
OpEntryPoint Fragment %2 "main"
OpExecutionMode %2 OriginUpperLeft
OpSource ESSL 310
OpName %2 "main"
%3 = OpTypeVoid
%4 = OpTypeFunction %3
%5 = OpTypeInt 32 1
%6 = OpTypePointer Function %5
%7 = OpTypeBool
%8 = OpConstantTrue %7
%2 = OpFunction %3 None %4
%9 = OpLabel
OpBranch %10
%10 = OpLabel
OpLoopMerge %11 %12 None
OpBranch %11
%12 = OpLabel
OpBranch %13
%13 = OpLabel
OpBranch %10
%11 = OpLabel
OpReturn
OpFunctionEnd
)";
CheckEqual(kEnv, after, context.get());
ops = SimpleConditionalBranchToBranchOpportunityFinder()
.GetAvailableOpportunities(context.get());
ASSERT_EQ(0, ops.size());
}
} // namespace
} // namespace reduce
} // namespace spvtools