[llvm-exegesis] Generate snippet setup code.
Summary:
This ensures that the snippet always sees the same values for registers,
making measurements reproducible.
This will also allow exploring different values.
Reviewers: gchatelet
Subscribers: tschuett, llvm-commits
Differential Revision: https://reviews.llvm.org/D48542
llvm-svn: 335465
diff --git a/llvm/unittests/tools/llvm-exegesis/Common/AssemblerUtils.h b/llvm/unittests/tools/llvm-exegesis/Common/AssemblerUtils.h
index 217ecc2..52133b4 100644
--- a/llvm/unittests/tools/llvm-exegesis/Common/AssemblerUtils.h
+++ b/llvm/unittests/tools/llvm-exegesis/Common/AssemblerUtils.h
@@ -36,9 +36,16 @@
}
template <class... Bs> inline void Check(llvm::MCInst MCInst, Bs... Bytes) {
- ExecutableFunction Function = (MCInst.getOpcode() == 0)
- ? assembleToFunction({})
- : assembleToFunction({MCInst});
+ CheckWithSetup(nullptr, {}, MCInst, Bytes...);
+ }
+
+ template <class... Bs>
+ inline void CheckWithSetup(const ExegesisTarget *ET,
+ llvm::ArrayRef<unsigned> RegsToDef,
+ llvm::MCInst MCInst, Bs... Bytes) {
+ ExecutableFunction Function =
+ (MCInst.getOpcode() == 0) ? assembleToFunction(ET, RegsToDef, {})
+ : assembleToFunction(ET, RegsToDef, {MCInst});
ASSERT_THAT(Function.getFunctionBytes().str(),
testing::ElementsAre(Bytes...));
if (CanExecute)
@@ -60,10 +67,13 @@
}
ExecutableFunction
- assembleToFunction(llvm::ArrayRef<llvm::MCInst> Instructions) {
+ assembleToFunction(const ExegesisTarget *ET,
+ llvm::ArrayRef<unsigned> RegsToDef,
+ llvm::ArrayRef<llvm::MCInst> Instructions) {
llvm::SmallString<256> Buffer;
llvm::raw_svector_ostream AsmStream(Buffer);
- assembleToStream(createTargetMachine(), Instructions, AsmStream);
+ assembleToStream(ET, createTargetMachine(), RegsToDef, Instructions,
+ AsmStream);
return ExecutableFunction(createTargetMachine(),
getObjectFromBuffer(AsmStream.str()));
}
diff --git a/llvm/unittests/tools/llvm-exegesis/X86/SnippetGeneratorTest.cpp b/llvm/unittests/tools/llvm-exegesis/X86/SnippetGeneratorTest.cpp
index d746bfc..f8a7ccd 100644
--- a/llvm/unittests/tools/llvm-exegesis/X86/SnippetGeneratorTest.cpp
+++ b/llvm/unittests/tools/llvm-exegesis/X86/SnippetGeneratorTest.cpp
@@ -25,6 +25,7 @@
using testing::HasSubstr;
using testing::Not;
using testing::SizeIs;
+using testing::UnorderedElementsAre;
MATCHER(IsInvalid, "") { return !arg.isValid(); }
MATCHER(IsReg, "") { return arg.isReg(); }
@@ -214,5 +215,74 @@
EXPECT_THAT(II.VariableValues[3], IsInvalid());
}
+class FakeBenchmarkRunner : public BenchmarkRunner {
+public:
+ using BenchmarkRunner::BenchmarkRunner;
+
+ Instruction createInstruction(unsigned Opcode) {
+ return Instruction(MCInstrInfo.get(Opcode), RATC);
+ }
+
+private:
+ InstructionBenchmark::ModeE getMode() const override {
+ return InstructionBenchmark::Unknown;
+ }
+
+ llvm::Expected<SnippetPrototype>
+ generatePrototype(unsigned Opcode) const override {
+ return llvm::make_error<llvm::StringError>("not implemented",
+ llvm::inconvertibleErrorCode());
+ }
+
+ std::vector<BenchmarkMeasure>
+ runMeasurements(const ExecutableFunction &EF,
+ const unsigned NumRepetitions) const override {
+ return {};
+ }
+};
+
+using FakeSnippetGeneratorTest = SnippetGeneratorTest<FakeBenchmarkRunner>;
+
+TEST_F(FakeSnippetGeneratorTest, ComputeRegsToDefAdd16ri) {
+ // ADD16ri:
+ // explicit def 0 : reg RegClass=GR16
+ // explicit use 1 : reg RegClass=GR16 | TIED_TO:0
+ // explicit use 2 : imm
+ // implicit def : EFLAGS
+ InstructionInstance II(Runner.createInstruction(llvm::X86::ADD16ri));
+ II.getValueFor(II.Instr.Variables[0]) =
+ llvm::MCOperand::createReg(llvm::X86::AX);
+ std::vector<InstructionInstance> Snippet;
+ Snippet.push_back(std::move(II));
+ const auto RegsToDef = Runner.computeRegsToDef(Snippet);
+ EXPECT_THAT(RegsToDef, UnorderedElementsAre(llvm::X86::AX));
+}
+
+TEST_F(FakeSnippetGeneratorTest, ComputeRegsToDefAdd64rr) {
+ // ADD64rr:
+ // mov64ri rax, 42
+ // add64rr rax, rax, rbx
+ // -> only rbx needs defining.
+ std::vector<InstructionInstance> Snippet;
+ {
+ InstructionInstance Mov(Runner.createInstruction(llvm::X86::MOV64ri));
+ Mov.getValueFor(Mov.Instr.Variables[0]) =
+ llvm::MCOperand::createReg(llvm::X86::RAX);
+ Mov.getValueFor(Mov.Instr.Variables[1]) = llvm::MCOperand::createImm(42);
+ Snippet.push_back(std::move(Mov));
+ }
+ {
+ InstructionInstance Add(Runner.createInstruction(llvm::X86::ADD64rr));
+ Add.getValueFor(Add.Instr.Variables[0]) =
+ llvm::MCOperand::createReg(llvm::X86::RAX);
+ Add.getValueFor(Add.Instr.Variables[1]) =
+ llvm::MCOperand::createReg(llvm::X86::RBX);
+ Snippet.push_back(std::move(Add));
+ }
+
+ const auto RegsToDef = Runner.computeRegsToDef(Snippet);
+ EXPECT_THAT(RegsToDef, UnorderedElementsAre(llvm::X86::RBX));
+}
+
} // namespace
} // namespace exegesis
diff --git a/llvm/unittests/tools/llvm-exegesis/X86/TargetTest.cpp b/llvm/unittests/tools/llvm-exegesis/X86/TargetTest.cpp
index f13e40c..547a78b 100644
--- a/llvm/unittests/tools/llvm-exegesis/X86/TargetTest.cpp
+++ b/llvm/unittests/tools/llvm-exegesis/X86/TargetTest.cpp
@@ -3,6 +3,7 @@
#include <cassert>
#include <memory>
+#include "MCTargetDesc/X86MCTargetDesc.h"
#include "gmock/gmock.h"
#include "gtest/gtest.h"
@@ -12,16 +13,31 @@
namespace {
+using testing::Gt;
using testing::NotNull;
+using testing::SizeIs;
class X86TargetTest : public ::testing::Test {
protected:
+ X86TargetTest()
+ : Target_(ExegesisTarget::lookup(llvm::Triple("x86_64-unknown-linux"))) {
+ EXPECT_THAT(Target_, NotNull());
+ }
static void SetUpTestCase() { InitializeX86ExegesisTarget(); }
+
+ const ExegesisTarget *const Target_;
};
-TEST_F(X86TargetTest, Lookup) {
- EXPECT_THAT(ExegesisTarget::lookup(llvm::Triple("x86_64-unknown-linux")),
- NotNull());
+TEST_F(X86TargetTest, SetRegToConstantGPR) {
+ const auto Insts = Target_->setRegToConstant(llvm::X86::EAX);
+ EXPECT_THAT(Insts, SizeIs(1));
+ EXPECT_EQ(Insts[0].getOpcode(), llvm::X86::MOV32ri);
+ EXPECT_EQ(Insts[0].getOperand(0).getReg(), llvm::X86::EAX);
+}
+
+TEST_F(X86TargetTest, SetRegToConstantXMM) {
+ const auto Insts = Target_->setRegToConstant(llvm::X86::XMM1);
+ EXPECT_THAT(Insts, SizeIs(Gt(0)));
}
} // namespace