SPIRV-Tools/test/lint/divergence_analysis_test.cpp
dong-ja 937227c761
Add divergence analysis to linter (#4465)
Currently, handles promotion of divergence due to reconvergence rules, but doesn't handle "late merges" caused by a later-than-necessary declared merge block.

Co-authored-by: Jakub Kuderski <kubak@google.com>
2021-08-23 17:03:28 -04:00

701 lines
23 KiB
C++

// Copyright (c) 2021 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/lint/divergence_analysis.h"
#include <string>
#include "gtest/gtest.h"
#include "source/opt/build_module.h"
#include "source/opt/ir_context.h"
#include "source/opt/module.h"
#include "spirv-tools/libspirv.h"
namespace spvtools {
namespace lint {
namespace {
void CLIMessageConsumer(spv_message_level_t level, const char*,
const spv_position_t& position, const char* message) {
switch (level) {
case SPV_MSG_FATAL:
case SPV_MSG_INTERNAL_ERROR:
case SPV_MSG_ERROR:
std::cerr << "error: line " << position.index << ": " << message
<< std::endl;
break;
case SPV_MSG_WARNING:
std::cout << "warning: line " << position.index << ": " << message
<< std::endl;
break;
case SPV_MSG_INFO:
std::cout << "info: line " << position.index << ": " << message
<< std::endl;
break;
default:
break;
}
}
class DivergenceTest : public ::testing::Test {
protected:
std::unique_ptr<opt::IRContext> context_;
std::unique_ptr<DivergenceAnalysis> divergence_;
void Build(std::string text, uint32_t function_id = 1) {
context_ = BuildModule(SPV_ENV_UNIVERSAL_1_0, CLIMessageConsumer, text,
SPV_TEXT_TO_BINARY_OPTION_PRESERVE_NUMERIC_IDS);
ASSERT_NE(nullptr, context_.get());
opt::Module* module = context_->module();
ASSERT_NE(nullptr, module);
// First function should have the given ID.
ASSERT_NE(module->begin(), module->end());
opt::Function* function = &*module->begin();
ASSERT_EQ(function->result_id(), function_id);
divergence_.reset(new DivergenceAnalysis(*context_));
divergence_->Run(function);
}
};
// Makes assertions a bit shorter.
using Level = DivergenceAnalysis::DivergenceLevel;
namespace {
std::string Preamble() {
return R"(
OpCapability Shader
OpMemoryModel Logical GLSL450
OpEntryPoint Fragment %1 "main" %x %y
OpExecutionMode %1 OriginLowerLeft
OpDecorate %y Flat
%void = OpTypeVoid
%void_f = OpTypeFunction %void
%bool = OpTypeBool
%float = OpTypeFloat 32
%false = OpConstantFalse %bool
%true = OpConstantTrue %bool
%zero = OpConstant %float 0
%one = OpConstant %float 1
%x_t = OpTypePointer Input %float
%x = OpVariable %x_t Input
%y = OpVariable %x_t Input
%1 = OpFunction %void None %void_f
)";
}
} // namespace
TEST_F(DivergenceTest, SimpleTest) {
// pseudocode:
// %10:
// %11 = load x
// if (%12 = (%11 < 0)) {
// %13:
// // do nothing
// }
// %14:
// return
ASSERT_NO_FATAL_FAILURE(Build(Preamble() + R"(
%10 = OpLabel
%11 = OpLoad %float %x
%12 = OpFOrdLessThan %bool %11 %zero
OpSelectionMerge %14 None
OpBranchConditional %12 %13 %14
%13 = OpLabel
OpBranch %14
%14 = OpLabel
OpReturn
OpFunctionEnd
)"));
// Control flow divergence.
EXPECT_EQ(Level::kUniform, divergence_->GetDivergenceLevel(10));
EXPECT_EQ(Level::kDivergent, divergence_->GetDivergenceLevel(13));
EXPECT_EQ(12, divergence_->GetDivergenceSource(13));
EXPECT_EQ(Level::kUniform, divergence_->GetDivergenceLevel(14));
// Value divergence.
EXPECT_EQ(Level::kDivergent, divergence_->GetDivergenceLevel(11));
EXPECT_EQ(0, divergence_->GetDivergenceSource(11));
EXPECT_EQ(Level::kDivergent, divergence_->GetDivergenceLevel(12));
EXPECT_EQ(11, divergence_->GetDivergenceSource(12));
}
TEST_F(DivergenceTest, FlowTypesTest) {
// pseudocode:
// %10:
// %11 = load x
// %12 = x < 0 // data -> data
// if (%12) {
// %13: // data -> control
// if (true) {
// %14: // control -> control
// }
// %15:
// %16 = 1
// } else {
// %17:
// %18 = 2
// }
// %19:
// %19 = phi(%16 from %15, %18 from %17) // control -> data
// return
ASSERT_NO_FATAL_FAILURE(Build(Preamble() + R"(
%10 = OpLabel
%11 = OpLoad %float %x
%12 = OpFOrdLessThan %bool %11 %zero
OpSelectionMerge %19 None
OpBranchConditional %12 %13 %17
%13 = OpLabel
OpSelectionMerge %15 None
OpBranchConditional %true %14 %15
%14 = OpLabel
OpBranch %15
%15 = OpLabel
%16 = OpFAdd %float %zero %zero
OpBranch %19
%17 = OpLabel
%18 = OpFAdd %float %zero %one
OpBranch %19
%19 = OpLabel
%20 = OpPhi %float %16 %15 %18 %17
OpReturn
OpFunctionEnd
)"));
EXPECT_EQ(Level::kUniform, divergence_->GetDivergenceLevel(10));
EXPECT_EQ(Level::kDivergent, divergence_->GetDivergenceLevel(11));
EXPECT_EQ(0, divergence_->GetDivergenceSource(11));
EXPECT_EQ(Level::kDivergent, divergence_->GetDivergenceLevel(12));
EXPECT_EQ(11, divergence_->GetDivergenceSource(12));
EXPECT_EQ(Level::kDivergent, divergence_->GetDivergenceLevel(13));
EXPECT_EQ(12, divergence_->GetDivergenceSource(13));
EXPECT_EQ(10, divergence_->GetDivergenceDependenceSource(13));
EXPECT_EQ(Level::kDivergent, divergence_->GetDivergenceLevel(14));
EXPECT_EQ(13, divergence_->GetDivergenceSource(14));
EXPECT_EQ(Level::kDivergent, divergence_->GetDivergenceLevel(15));
EXPECT_EQ(12, divergence_->GetDivergenceSource(15));
EXPECT_EQ(10, divergence_->GetDivergenceDependenceSource(15));
EXPECT_EQ(Level::kUniform, divergence_->GetDivergenceLevel(16));
EXPECT_EQ(Level::kDivergent, divergence_->GetDivergenceLevel(17));
EXPECT_EQ(12, divergence_->GetDivergenceSource(17));
EXPECT_EQ(10, divergence_->GetDivergenceDependenceSource(17));
EXPECT_EQ(Level::kUniform, divergence_->GetDivergenceLevel(18));
EXPECT_EQ(Level::kUniform, divergence_->GetDivergenceLevel(19));
EXPECT_EQ(Level::kDivergent, divergence_->GetDivergenceLevel(20));
EXPECT_TRUE(divergence_->GetDivergenceSource(20) == 15 ||
divergence_->GetDivergenceDependenceSource(20) == 17)
<< "Got: " << divergence_->GetDivergenceDependenceSource(20);
}
TEST_F(DivergenceTest, ExitDependenceTest) {
// pseudocode:
// %10:
// %11 = load x
// %12 = %11 < 0
// %13:
// do {
// %14:
// if (%12) {
// %15:
// continue;
// }
// %16:
// %17:
// continue;
// } %18: while(false);
// %19:
// return
ASSERT_NO_FATAL_FAILURE(Build(Preamble() + R"(
%10 = OpLabel
%11 = OpLoad %float %x
%12 = OpFOrdLessThan %bool %11 %zero ; data -> data
OpBranch %13
%13 = OpLabel
OpLoopMerge %19 %18 None
OpBranch %14
%14 = OpLabel
OpSelectionMerge %16 None
OpBranchConditional %12 %15 %16
%15 = OpLabel
OpBranch %18 ; continue
%16 = OpLabel
OpBranch %17
%17 = OpLabel
OpBranch %18 ; continue
%18 = OpLabel
OpBranchConditional %false %13 %19
%19 = OpLabel
OpReturn
OpFunctionEnd
)"));
EXPECT_EQ(Level::kUniform, divergence_->GetDivergenceLevel(10));
EXPECT_EQ(Level::kDivergent, divergence_->GetDivergenceLevel(11));
EXPECT_EQ(0, divergence_->GetDivergenceSource(11));
EXPECT_EQ(Level::kDivergent, divergence_->GetDivergenceLevel(12));
EXPECT_EQ(11, divergence_->GetDivergenceSource(12));
// Since both branches continue, there's no divergent control dependence
// to 13.
EXPECT_EQ(Level::kUniform, divergence_->GetDivergenceLevel(13));
EXPECT_EQ(Level::kUniform, divergence_->GetDivergenceLevel(14));
EXPECT_EQ(Level::kDivergent, divergence_->GetDivergenceLevel(15));
EXPECT_EQ(12, divergence_->GetDivergenceSource(15));
EXPECT_EQ(14, divergence_->GetDivergenceDependenceSource(15));
// These two blocks are outside the if but are still control dependent.
EXPECT_EQ(Level::kDivergent, divergence_->GetDivergenceLevel(16));
EXPECT_EQ(12, divergence_->GetDivergenceSource(16));
EXPECT_EQ(14, divergence_->GetDivergenceDependenceSource(16));
EXPECT_EQ(Level::kDivergent, divergence_->GetDivergenceLevel(17));
EXPECT_EQ(12, divergence_->GetDivergenceSource(17));
EXPECT_EQ(14, divergence_->GetDivergenceDependenceSource(17));
EXPECT_EQ(Level::kUniform, divergence_->GetDivergenceLevel(18));
EXPECT_EQ(Level::kUniform, divergence_->GetDivergenceLevel(19));
}
TEST_F(DivergenceTest, ReconvergencePromotionTest) {
// pseudocode:
// %10:
// %11 = load y
// %12 = %11 < 0
// if (%12) {
// %13:
// %14:
// %15:
// if (true) {
// %16:
// }
// // Reconvergence *not* guaranteed as
// // control is not uniform on the IG level
// // at %15.
// %17:
// %18:
// %19:
// %20 = load x
// }
// %21:
// %22 = phi(%11, %20)
// return
ASSERT_NO_FATAL_FAILURE(Build(Preamble() + R"(
%10 = OpLabel
%11 = OpLoad %float %y
%12 = OpFOrdLessThan %bool %11 %zero
OpSelectionMerge %21 None
OpBranchConditional %12 %13 %21
%13 = OpLabel
OpBranch %14
%14 = OpLabel
OpBranch %15
%15 = OpLabel
OpSelectionMerge %17 None
OpBranchConditional %true %16 %17
%16 = OpLabel
OpBranch %17
%17 = OpLabel
OpBranch %18
%18 = OpLabel
OpBranch %19
%19 = OpLabel
%20 = OpLoad %float %y
OpBranch %21
%21 = OpLabel
%22 = OpPhi %float %11 %10 %20 %19
OpReturn
OpFunctionEnd
)"));
ASSERT_EQ(Level::kUniform, divergence_->GetDivergenceLevel(10));
ASSERT_EQ(Level::kUniform, divergence_->GetDivergenceLevel(21));
ASSERT_EQ(Level::kPartiallyUniform, divergence_->GetDivergenceLevel(11));
ASSERT_EQ(0, divergence_->GetDivergenceSource(11));
ASSERT_EQ(Level::kPartiallyUniform, divergence_->GetDivergenceLevel(12));
ASSERT_EQ(11, divergence_->GetDivergenceSource(12));
ASSERT_EQ(Level::kPartiallyUniform, divergence_->GetDivergenceLevel(13));
ASSERT_EQ(12, divergence_->GetDivergenceSource(13));
ASSERT_EQ(10, divergence_->GetDivergenceDependenceSource(13));
ASSERT_EQ(Level::kPartiallyUniform, divergence_->GetDivergenceLevel(14));
ASSERT_EQ(12, divergence_->GetDivergenceSource(14));
ASSERT_EQ(10, divergence_->GetDivergenceDependenceSource(14));
ASSERT_EQ(Level::kPartiallyUniform, divergence_->GetDivergenceLevel(15));
ASSERT_EQ(12, divergence_->GetDivergenceSource(15));
ASSERT_EQ(10, divergence_->GetDivergenceDependenceSource(15));
ASSERT_EQ(Level::kPartiallyUniform, divergence_->GetDivergenceLevel(16));
ASSERT_EQ(15, divergence_->GetDivergenceSource(16));
ASSERT_EQ(Level::kDivergent, divergence_->GetDivergenceLevel(17));
ASSERT_EQ(12, divergence_->GetDivergenceSource(17));
ASSERT_EQ(Level::kDivergent, divergence_->GetDivergenceLevel(18));
ASSERT_EQ(12, divergence_->GetDivergenceSource(18));
ASSERT_EQ(Level::kDivergent, divergence_->GetDivergenceLevel(19));
ASSERT_EQ(12, divergence_->GetDivergenceSource(19));
ASSERT_EQ(Level::kPartiallyUniform, divergence_->GetDivergenceLevel(20));
ASSERT_EQ(0, divergence_->GetDivergenceSource(20));
ASSERT_EQ(Level::kDivergent, divergence_->GetDivergenceLevel(22));
ASSERT_EQ(19, divergence_->GetDivergenceSource(22));
ASSERT_EQ(10, divergence_->GetDivergenceDependenceSource(15));
}
TEST_F(DivergenceTest, FunctionCallTest) {
// pseudocode:
// %2() {
// %20:
// %21 = load x
// %22 = %21 < 0
// if (%22) {
// %23:
// return
// }
// %24:
// return
// }
//
// main() {
// %10:
// %11 = %2();
// // Reconvergence *not* guaranteed.
// %12:
// return
// }
ASSERT_NO_FATAL_FAILURE(Build(Preamble() + R"(
%10 = OpLabel
%11 = OpFunctionCall %void %2
OpBranch %12
%12 = OpLabel
OpReturn
OpFunctionEnd
%2 = OpFunction %void None %void_f
%20 = OpLabel
%21 = OpLoad %float %x
%22 = OpFOrdLessThan %bool %21 %zero
OpSelectionMerge %24 None
OpBranchConditional %22 %23 %24
%23 = OpLabel
OpReturn
%24 = OpLabel
OpReturn
OpFunctionEnd
)"));
EXPECT_EQ(Level::kUniform, divergence_->GetDivergenceLevel(10));
// Conservatively assume function return value is uniform.
EXPECT_EQ(Level::kUniform, divergence_->GetDivergenceLevel(11));
// TODO(dongja): blocks reachable from diverging function calls should be
// divergent.
// EXPECT_EQ(Level::kDivergent, divergence_->GetDivergenceLevel(12));
EXPECT_EQ(Level::kUniform, divergence_->GetDivergenceLevel(12)); // Wrong!
}
TEST_F(DivergenceTest, LateMergeTest) {
// pseudocode:
// %10:
// %11 = load y
// %12 = %11 < 0
// [merge: %15]
// if (%12) {
// %13:
// }
// %14: // Reconvergence hasn't happened by here.
// %15:
// return
ASSERT_NO_FATAL_FAILURE(Build(Preamble() + R"(
%10 = OpLabel
%11 = OpLoad %float %x
%12 = OpFOrdLessThan %bool %11 %zero
OpSelectionMerge %15 None
OpBranchConditional %12 %13 %14
%13 = OpLabel
OpBranch %14
%14 = OpLabel
OpBranch %15
%15 = OpLabel
OpReturn
OpFunctionEnd
)"));
EXPECT_EQ(Level::kUniform, divergence_->GetDivergenceLevel(10));
EXPECT_EQ(Level::kDivergent, divergence_->GetDivergenceLevel(11));
EXPECT_EQ(Level::kDivergent, divergence_->GetDivergenceLevel(12));
EXPECT_EQ(Level::kDivergent, divergence_->GetDivergenceLevel(13));
// TODO(dongja):
// EXPECT_EQ(Level::kDivergent, divergence_->GetDivergenceLevel(14));
EXPECT_EQ(Level::kUniform, divergence_->GetDivergenceLevel(14)); // Wrong!
EXPECT_EQ(Level::kUniform, divergence_->GetDivergenceLevel(15));
}
// The following series of tests makes sure that we find the least fixpoint.
TEST_F(DivergenceTest, UniformFixpointTest) {
// pseudocode:
// %10:
// %20 = load x
// %21 = load y
// do {
// %11:
// %12:
// %13 = phi(%zero from %11, %14 from %16)
// %14 = %13 + 1
// %15 = %13 < 1
// } %16: while (%15)
// %17:
ASSERT_NO_FATAL_FAILURE(Build(Preamble() + R"(
%10 = OpLabel
%20 = OpLoad %float %x
%21 = OpLoad %float %y
OpBranch %11
%11 = OpLabel
%13 = OpPhi %float %zero %10 %14 %16
OpLoopMerge %17 %16 None
OpBranch %12
%12 = OpLabel
%14 = OpFAdd %float %13 %one
%15 = OpFOrdLessThan %bool %13 %one
OpBranch %16
%16 = OpLabel
OpBranchConditional %15 %11 %17
%17 = OpLabel
OpReturn
OpFunctionEnd
)"));
EXPECT_EQ(Level::kUniform, divergence_->GetDivergenceLevel(10));
EXPECT_EQ(Level::kUniform, divergence_->GetDivergenceLevel(11));
EXPECT_EQ(Level::kUniform, divergence_->GetDivergenceLevel(12));
EXPECT_EQ(Level::kUniform, divergence_->GetDivergenceLevel(13));
EXPECT_EQ(Level::kUniform, divergence_->GetDivergenceLevel(14));
EXPECT_EQ(Level::kUniform, divergence_->GetDivergenceLevel(15));
EXPECT_EQ(Level::kUniform, divergence_->GetDivergenceLevel(16));
EXPECT_EQ(Level::kUniform, divergence_->GetDivergenceLevel(17));
}
TEST_F(DivergenceTest, PartiallyUniformFixpointTest) {
// pseudocode:
// %10:
// %20 = load x
// %21 = load y
// do {
// %11:
// %12:
// %13 = phi(%zero from %11, %14 from %16)
// %14 = %13 + 1
// %15 = %13 < %21
// } %16: while (%15)
// %17:
ASSERT_NO_FATAL_FAILURE(Build(Preamble() + R"(
%10 = OpLabel
%20 = OpLoad %float %x
%21 = OpLoad %float %y
OpBranch %11
%11 = OpLabel
%13 = OpPhi %float %zero %10 %14 %16
OpLoopMerge %17 %16 None
OpBranch %12
%12 = OpLabel
%14 = OpFAdd %float %13 %one
%15 = OpFOrdLessThan %bool %13 %21
OpBranch %16
%16 = OpLabel
OpBranchConditional %15 %11 %17
%17 = OpLabel
OpReturn
OpFunctionEnd
)"));
EXPECT_EQ(Level::kUniform, divergence_->GetDivergenceLevel(10));
EXPECT_EQ(Level::kPartiallyUniform, divergence_->GetDivergenceLevel(11));
EXPECT_EQ(Level::kPartiallyUniform, divergence_->GetDivergenceLevel(12));
EXPECT_EQ(Level::kPartiallyUniform, divergence_->GetDivergenceLevel(13));
EXPECT_EQ(Level::kPartiallyUniform, divergence_->GetDivergenceLevel(14));
EXPECT_EQ(Level::kPartiallyUniform, divergence_->GetDivergenceLevel(15));
EXPECT_EQ(Level::kPartiallyUniform, divergence_->GetDivergenceLevel(16));
EXPECT_EQ(Level::kUniform, divergence_->GetDivergenceLevel(17));
}
TEST_F(DivergenceTest, DivergentFixpointTest) {
// pseudocode:
// %10:
// %20 = load x
// %21 = load y
// do {
// %11:
// %12:
// %13 = phi(%zero from %11, %14 from %16)
// %14 = %13 + 1
// %15 = %13 < %20
// } %16: while (%15)
// %17:
ASSERT_NO_FATAL_FAILURE(Build(Preamble() + R"(
%10 = OpLabel
%20 = OpLoad %float %x
%21 = OpLoad %float %y
OpBranch %11
%11 = OpLabel
%13 = OpPhi %float %zero %10 %14 %16
OpLoopMerge %17 %16 None
OpBranch %12
%12 = OpLabel
%14 = OpFAdd %float %13 %one
%15 = OpFOrdLessThan %bool %13 %20
OpBranch %16
%16 = OpLabel
OpBranchConditional %15 %11 %17
%17 = OpLabel
OpReturn
OpFunctionEnd
)"));
EXPECT_EQ(Level::kUniform, divergence_->GetDivergenceLevel(10));
EXPECT_EQ(Level::kDivergent, divergence_->GetDivergenceLevel(11));
EXPECT_EQ(Level::kDivergent, divergence_->GetDivergenceLevel(12));
EXPECT_EQ(Level::kDivergent, divergence_->GetDivergenceLevel(13));
EXPECT_EQ(Level::kDivergent, divergence_->GetDivergenceLevel(14));
EXPECT_EQ(Level::kDivergent, divergence_->GetDivergenceLevel(15));
EXPECT_EQ(Level::kDivergent, divergence_->GetDivergenceLevel(16));
EXPECT_EQ(Level::kUniform, divergence_->GetDivergenceLevel(17));
}
TEST_F(DivergenceTest, DivergentOverridesPartiallyUniformTest) {
// pseudocode:
// %10:
// %20 = load x
// %21 = load y
// %11:
// do {
// %12:
// %13 = phi(%21 from %11, %14 from %16)
// %14 = %13 + 1
// %15 = %13 < %20
// } %16: while (%15)
// %17:
ASSERT_NO_FATAL_FAILURE(Build(Preamble() + R"(
%10 = OpLabel
%20 = OpLoad %float %x
%21 = OpLoad %float %y
OpBranch %11
%11 = OpLabel
%13 = OpPhi %float %zero %10 %14 %16
OpLoopMerge %17 %16 None
OpBranch %12
%12 = OpLabel
%14 = OpFAdd %float %13 %one
%15 = OpFOrdLessThan %bool %13 %20
OpBranch %16
%16 = OpLabel
OpBranchConditional %15 %11 %17
%17 = OpLabel
OpReturn
OpFunctionEnd
)"));
EXPECT_EQ(Level::kUniform, divergence_->GetDivergenceLevel(10));
EXPECT_EQ(Level::kDivergent, divergence_->GetDivergenceLevel(11));
EXPECT_EQ(Level::kDivergent, divergence_->GetDivergenceLevel(12));
EXPECT_EQ(Level::kDivergent, divergence_->GetDivergenceLevel(13));
EXPECT_EQ(Level::kDivergent, divergence_->GetDivergenceLevel(14));
EXPECT_EQ(Level::kDivergent, divergence_->GetDivergenceLevel(15));
EXPECT_EQ(Level::kDivergent, divergence_->GetDivergenceLevel(16));
EXPECT_EQ(Level::kUniform, divergence_->GetDivergenceLevel(17));
}
TEST_F(DivergenceTest, NestedFixpointTest) {
// pseudocode:
// %10:
// %20 = load x
// %21 = load y
// do {
// %22:
// %23:
// %24 = phi(%zero from %22, %25 from %26)
// %11:
// do {
// %12:
// %13 = phi(%zero from %11, %14 from %16)
// %14 = %13 + 1
// %15 = %13 < %24
// } %16: while (%15)
// %17:
// %25 = load x
// } %26: while (false)
// %27:
// return
ASSERT_NO_FATAL_FAILURE(Build(Preamble() + R"(
%10 = OpLabel
%20 = OpLoad %float %x
%21 = OpLoad %float %y
OpBranch %22
%22 = OpLabel
%24 = OpPhi %float %zero %10 %25 %26
OpLoopMerge %27 %26 None
OpBranch %23
%23 = OpLabel
OpBranch %11
%11 = OpLabel
%13 = OpPhi %float %zero %23 %14 %16
OpLoopMerge %17 %16 None
OpBranch %12
%12 = OpLabel
%14 = OpFAdd %float %13 %one
%15 = OpFOrdLessThan %bool %13 %24
OpBranch %16
%16 = OpLabel
OpBranchConditional %15 %11 %17
%17 = OpLabel
%25 = OpLoad %float %x
OpBranch %26
%26 = OpLabel
OpBranchConditional %false %22 %27
%27 = OpLabel
OpReturn
OpFunctionEnd
)"));
// This test makes sure that divergent values flowing upward can influence the
// fixpoint of a loop.
EXPECT_EQ(Level::kUniform, divergence_->GetDivergenceLevel(10));
EXPECT_EQ(Level::kDivergent, divergence_->GetDivergenceLevel(11));
EXPECT_EQ(Level::kDivergent, divergence_->GetDivergenceLevel(12));
EXPECT_EQ(Level::kDivergent, divergence_->GetDivergenceLevel(13));
EXPECT_EQ(Level::kDivergent, divergence_->GetDivergenceLevel(14));
EXPECT_EQ(Level::kDivergent, divergence_->GetDivergenceLevel(15));
EXPECT_EQ(Level::kDivergent, divergence_->GetDivergenceLevel(16));
// Control of the outer loop is still uniform.
EXPECT_EQ(Level::kUniform, divergence_->GetDivergenceLevel(17));
EXPECT_EQ(Level::kUniform, divergence_->GetDivergenceLevel(22));
EXPECT_EQ(Level::kUniform, divergence_->GetDivergenceLevel(23));
// Seed divergent values.
EXPECT_EQ(Level::kDivergent, divergence_->GetDivergenceLevel(24));
EXPECT_EQ(Level::kDivergent, divergence_->GetDivergenceLevel(25));
// Outer loop control.
EXPECT_EQ(Level::kUniform, divergence_->GetDivergenceLevel(26));
// Merged.
EXPECT_EQ(Level::kUniform, divergence_->GetDivergenceLevel(27));
}
} // namespace
} // namespace lint
} // namespace spvtools