llvm-project/llvm/unittests/Transforms/Utils/CodeExtractorTest.cpp
Andrew Litteken 144cd22bae [CodeExtractor] Creating exit stubs based off original order branch instructions.
Previously the CodeExtractor created exit stubs, and the subsequent return value of the outlined function based on the order of out-of-region blocks after splitting any phi nodes, and collecting the blocks to be outlined. This could cause differences in order if there was a difference of exit block phi nodes between the two regions. This patch moves the collection of the output target blocks to be before this occurs, so that the assignment of target block to output value will be the same, regardless of the contents of the output block.

Reviewers: paquette, roelofs

Differential Revision: https://reviews.llvm.org/D108657
2021-09-08 15:15:15 -07:00

508 lines
16 KiB
C++

//===- CodeExtractor.cpp - Unit tests for CodeExtractor -------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "llvm/Transforms/Utils/CodeExtractor.h"
#include "llvm/AsmParser/Parser.h"
#include "llvm/Analysis/AssumptionCache.h"
#include "llvm/IR/BasicBlock.h"
#include "llvm/IR/Dominators.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/Verifier.h"
#include "llvm/IRReader/IRReader.h"
#include "llvm/Support/SourceMgr.h"
#include "gtest/gtest.h"
using namespace llvm;
namespace {
BasicBlock *getBlockByName(Function *F, StringRef name) {
for (auto &BB : *F)
if (BB.getName() == name)
return &BB;
return nullptr;
}
TEST(CodeExtractor, ExitStub) {
LLVMContext Ctx;
SMDiagnostic Err;
std::unique_ptr<Module> M(parseAssemblyString(R"invalid(
define i32 @foo(i32 %x, i32 %y, i32 %z) {
header:
%0 = icmp ugt i32 %x, %y
br i1 %0, label %body1, label %body2
body1:
%1 = add i32 %z, 2
br label %notExtracted
body2:
%2 = mul i32 %z, 7
br label %notExtracted
notExtracted:
%3 = phi i32 [ %1, %body1 ], [ %2, %body2 ]
%4 = add i32 %3, %x
ret i32 %4
}
)invalid",
Err, Ctx));
Function *Func = M->getFunction("foo");
SmallVector<BasicBlock *, 3> Candidates{ getBlockByName(Func, "header"),
getBlockByName(Func, "body1"),
getBlockByName(Func, "body2") };
CodeExtractor CE(Candidates);
EXPECT_TRUE(CE.isEligible());
CodeExtractorAnalysisCache CEAC(*Func);
Function *Outlined = CE.extractCodeRegion(CEAC);
EXPECT_TRUE(Outlined);
BasicBlock *Exit = getBlockByName(Func, "notExtracted");
BasicBlock *ExitSplit = getBlockByName(Outlined, "notExtracted.split");
// Ensure that PHI in exit block has only one incoming value (from code
// replacer block).
EXPECT_TRUE(Exit && cast<PHINode>(Exit->front()).getNumIncomingValues() == 1);
// Ensure that there is a PHI in outlined function with 2 incoming values.
EXPECT_TRUE(ExitSplit &&
cast<PHINode>(ExitSplit->front()).getNumIncomingValues() == 2);
EXPECT_FALSE(verifyFunction(*Outlined));
EXPECT_FALSE(verifyFunction(*Func));
}
TEST(CodeExtractor, InputOutputMonitoring) {
LLVMContext Ctx;
SMDiagnostic Err;
std::unique_ptr<Module> M(parseAssemblyString(R"invalid(
define i32 @foo(i32 %x, i32 %y, i32 %z) {
header:
%0 = icmp ugt i32 %x, %y
br i1 %0, label %body1, label %body2
body1:
%1 = add i32 %z, 2
br label %notExtracted
body2:
%2 = mul i32 %z, 7
br label %notExtracted
notExtracted:
%3 = phi i32 [ %1, %body1 ], [ %2, %body2 ]
%4 = add i32 %3, %x
ret i32 %4
}
)invalid",
Err, Ctx));
Function *Func = M->getFunction("foo");
SmallVector<BasicBlock *, 3> Candidates{getBlockByName(Func, "header"),
getBlockByName(Func, "body1"),
getBlockByName(Func, "body2")};
CodeExtractor CE(Candidates);
EXPECT_TRUE(CE.isEligible());
CodeExtractorAnalysisCache CEAC(*Func);
SetVector<Value *> Inputs, Outputs;
Function *Outlined = CE.extractCodeRegion(CEAC, Inputs, Outputs);
EXPECT_TRUE(Outlined);
EXPECT_EQ(Inputs.size(), 3u);
EXPECT_EQ(Inputs[0], Func->getArg(2));
EXPECT_EQ(Inputs[1], Func->getArg(0));
EXPECT_EQ(Inputs[2], Func->getArg(1));
EXPECT_EQ(Outputs.size(), 1u);
StoreInst *SI = cast<StoreInst>(Outlined->getArg(3)->user_back());
Value *OutputVal = SI->getValueOperand();
EXPECT_EQ(Outputs[0], OutputVal);
BasicBlock *Exit = getBlockByName(Func, "notExtracted");
BasicBlock *ExitSplit = getBlockByName(Outlined, "notExtracted.split");
// Ensure that PHI in exit block has only one incoming value (from code
// replacer block).
EXPECT_TRUE(Exit && cast<PHINode>(Exit->front()).getNumIncomingValues() == 1);
// Ensure that there is a PHI in outlined function with 2 incoming values.
EXPECT_TRUE(ExitSplit &&
cast<PHINode>(ExitSplit->front()).getNumIncomingValues() == 2);
EXPECT_FALSE(verifyFunction(*Outlined));
EXPECT_FALSE(verifyFunction(*Func));
}
TEST(CodeExtractor, ExitBlockOrderingPhis) {
LLVMContext Ctx;
SMDiagnostic Err;
std::unique_ptr<Module> M(parseAssemblyString(R"invalid(
define void @foo(i32 %a, i32 %b) {
entry:
%0 = alloca i32, align 4
br label %test0
test0:
%c = load i32, i32* %0, align 4
br label %test1
test1:
%e = load i32, i32* %0, align 4
br i1 true, label %first, label %test
test:
%d = load i32, i32* %0, align 4
br i1 true, label %first, label %next
first:
%1 = phi i32 [ %c, %test ], [ %e, %test1 ]
ret void
next:
%2 = add i32 %d, 1
%3 = add i32 %e, 1
ret void
}
)invalid",
Err, Ctx));
Function *Func = M->getFunction("foo");
SmallVector<BasicBlock *, 3> Candidates{ getBlockByName(Func, "test0"),
getBlockByName(Func, "test1"),
getBlockByName(Func, "test") };
CodeExtractor CE(Candidates);
EXPECT_TRUE(CE.isEligible());
CodeExtractorAnalysisCache CEAC(*Func);
Function *Outlined = CE.extractCodeRegion(CEAC);
EXPECT_TRUE(Outlined);
BasicBlock *FirstExitStub = getBlockByName(Outlined, "first.exitStub");
BasicBlock *NextExitStub = getBlockByName(Outlined, "next.exitStub");
Instruction *FirstTerm = FirstExitStub->getTerminator();
ReturnInst *FirstReturn = dyn_cast<ReturnInst>(FirstTerm);
EXPECT_TRUE(FirstReturn);
ConstantInt *CIFirst = dyn_cast<ConstantInt>(FirstReturn->getReturnValue());
EXPECT_TRUE(CIFirst->getLimitedValue() == 1u);
Instruction *NextTerm = NextExitStub->getTerminator();
ReturnInst *NextReturn = dyn_cast<ReturnInst>(NextTerm);
EXPECT_TRUE(NextReturn);
ConstantInt *CINext = dyn_cast<ConstantInt>(NextReturn->getReturnValue());
EXPECT_TRUE(CINext->getLimitedValue() == 0u);
EXPECT_FALSE(verifyFunction(*Outlined));
EXPECT_FALSE(verifyFunction(*Func));
}
TEST(CodeExtractor, ExitBlockOrdering) {
LLVMContext Ctx;
SMDiagnostic Err;
std::unique_ptr<Module> M(parseAssemblyString(R"invalid(
define void @foo(i32 %a, i32 %b) {
entry:
%0 = alloca i32, align 4
br label %test0
test0:
%c = load i32, i32* %0, align 4
br label %test1
test1:
%e = load i32, i32* %0, align 4
br i1 true, label %first, label %test
test:
%d = load i32, i32* %0, align 4
br i1 true, label %first, label %next
first:
ret void
next:
%1 = add i32 %d, 1
%2 = add i32 %e, 1
ret void
}
)invalid",
Err, Ctx));
Function *Func = M->getFunction("foo");
SmallVector<BasicBlock *, 3> Candidates{ getBlockByName(Func, "test0"),
getBlockByName(Func, "test1"),
getBlockByName(Func, "test") };
CodeExtractor CE(Candidates);
EXPECT_TRUE(CE.isEligible());
CodeExtractorAnalysisCache CEAC(*Func);
Function *Outlined = CE.extractCodeRegion(CEAC);
EXPECT_TRUE(Outlined);
BasicBlock *FirstExitStub = getBlockByName(Outlined, "first.exitStub");
BasicBlock *NextExitStub = getBlockByName(Outlined, "next.exitStub");
Instruction *FirstTerm = FirstExitStub->getTerminator();
ReturnInst *FirstReturn = dyn_cast<ReturnInst>(FirstTerm);
EXPECT_TRUE(FirstReturn);
ConstantInt *CIFirst = dyn_cast<ConstantInt>(FirstReturn->getReturnValue());
EXPECT_TRUE(CIFirst->getLimitedValue() == 1u);
Instruction *NextTerm = NextExitStub->getTerminator();
ReturnInst *NextReturn = dyn_cast<ReturnInst>(NextTerm);
EXPECT_TRUE(NextReturn);
ConstantInt *CINext = dyn_cast<ConstantInt>(NextReturn->getReturnValue());
EXPECT_TRUE(CINext->getLimitedValue() == 0u);
EXPECT_FALSE(verifyFunction(*Outlined));
EXPECT_FALSE(verifyFunction(*Func));
}
TEST(CodeExtractor, ExitPHIOnePredFromRegion) {
LLVMContext Ctx;
SMDiagnostic Err;
std::unique_ptr<Module> M(parseAssemblyString(R"invalid(
define i32 @foo() {
header:
br i1 undef, label %extracted1, label %pred
pred:
br i1 undef, label %exit1, label %exit2
extracted1:
br i1 undef, label %extracted2, label %exit1
extracted2:
br label %exit2
exit1:
%0 = phi i32 [ 1, %extracted1 ], [ 2, %pred ]
ret i32 %0
exit2:
%1 = phi i32 [ 3, %extracted2 ], [ 4, %pred ]
ret i32 %1
}
)invalid", Err, Ctx));
Function *Func = M->getFunction("foo");
SmallVector<BasicBlock *, 2> ExtractedBlocks{
getBlockByName(Func, "extracted1"),
getBlockByName(Func, "extracted2")
};
CodeExtractor CE(ExtractedBlocks);
EXPECT_TRUE(CE.isEligible());
CodeExtractorAnalysisCache CEAC(*Func);
Function *Outlined = CE.extractCodeRegion(CEAC);
EXPECT_TRUE(Outlined);
BasicBlock *Exit1 = getBlockByName(Func, "exit1");
BasicBlock *Exit2 = getBlockByName(Func, "exit2");
// Ensure that PHIs in exits are not splitted (since that they have only one
// incoming value from extracted region).
EXPECT_TRUE(Exit1 &&
cast<PHINode>(Exit1->front()).getNumIncomingValues() == 2);
EXPECT_TRUE(Exit2 &&
cast<PHINode>(Exit2->front()).getNumIncomingValues() == 2);
EXPECT_FALSE(verifyFunction(*Outlined));
EXPECT_FALSE(verifyFunction(*Func));
}
TEST(CodeExtractor, StoreOutputInvokeResultAfterEHPad) {
LLVMContext Ctx;
SMDiagnostic Err;
std::unique_ptr<Module> M(parseAssemblyString(R"invalid(
declare i8 @hoge()
define i32 @foo() personality i8* null {
entry:
%call = invoke i8 @hoge()
to label %invoke.cont unwind label %lpad
invoke.cont: ; preds = %entry
unreachable
lpad: ; preds = %entry
%0 = landingpad { i8*, i32 }
catch i8* null
br i1 undef, label %catch, label %finally.catchall
catch: ; preds = %lpad
%call2 = invoke i8 @hoge()
to label %invoke.cont2 unwind label %lpad2
invoke.cont2: ; preds = %catch
%call3 = invoke i8 @hoge()
to label %invoke.cont3 unwind label %lpad2
invoke.cont3: ; preds = %invoke.cont2
unreachable
lpad2: ; preds = %invoke.cont2, %catch
%ex.1 = phi i8* [ undef, %invoke.cont2 ], [ null, %catch ]
%1 = landingpad { i8*, i32 }
catch i8* null
br label %finally.catchall
finally.catchall: ; preds = %lpad33, %lpad
%ex.2 = phi i8* [ %ex.1, %lpad2 ], [ null, %lpad ]
unreachable
}
)invalid", Err, Ctx));
if (!M) {
Err.print("unit", errs());
exit(1);
}
Function *Func = M->getFunction("foo");
EXPECT_FALSE(verifyFunction(*Func, &errs()));
SmallVector<BasicBlock *, 2> ExtractedBlocks{
getBlockByName(Func, "catch"),
getBlockByName(Func, "invoke.cont2"),
getBlockByName(Func, "invoke.cont3"),
getBlockByName(Func, "lpad2")
};
CodeExtractor CE(ExtractedBlocks);
EXPECT_TRUE(CE.isEligible());
CodeExtractorAnalysisCache CEAC(*Func);
Function *Outlined = CE.extractCodeRegion(CEAC);
EXPECT_TRUE(Outlined);
EXPECT_FALSE(verifyFunction(*Outlined, &errs()));
EXPECT_FALSE(verifyFunction(*Func, &errs()));
}
TEST(CodeExtractor, StoreOutputInvokeResultInExitStub) {
LLVMContext Ctx;
SMDiagnostic Err;
std::unique_ptr<Module> M(parseAssemblyString(R"invalid(
declare i32 @bar()
define i32 @foo() personality i8* null {
entry:
%0 = invoke i32 @bar() to label %exit unwind label %lpad
exit:
ret i32 %0
lpad:
%1 = landingpad { i8*, i32 }
cleanup
resume { i8*, i32 } %1
}
)invalid",
Err, Ctx));
Function *Func = M->getFunction("foo");
SmallVector<BasicBlock *, 1> Blocks{ getBlockByName(Func, "entry"),
getBlockByName(Func, "lpad") };
CodeExtractor CE(Blocks);
EXPECT_TRUE(CE.isEligible());
CodeExtractorAnalysisCache CEAC(*Func);
Function *Outlined = CE.extractCodeRegion(CEAC);
EXPECT_TRUE(Outlined);
EXPECT_FALSE(verifyFunction(*Outlined));
EXPECT_FALSE(verifyFunction(*Func));
}
TEST(CodeExtractor, ExtractAndInvalidateAssumptionCache) {
LLVMContext Ctx;
SMDiagnostic Err;
std::unique_ptr<Module> M(parseAssemblyString(R"ir(
target datalayout = "e-m:e-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128"
target triple = "aarch64"
%b = type { i64 }
declare void @g(i8*)
declare void @llvm.assume(i1) #0
define void @test() {
entry:
br label %label
label:
%0 = load %b*, %b** inttoptr (i64 8 to %b**), align 8
%1 = getelementptr inbounds %b, %b* %0, i64 undef, i32 0
%2 = load i64, i64* %1, align 8
%3 = icmp ugt i64 %2, 1
br i1 %3, label %if.then, label %if.else
if.then:
unreachable
if.else:
call void @g(i8* undef)
store i64 undef, i64* null, align 536870912
%4 = icmp eq i64 %2, 0
call void @llvm.assume(i1 %4)
unreachable
}
attributes #0 = { nounwind willreturn }
)ir",
Err, Ctx));
assert(M && "Could not parse module?");
Function *Func = M->getFunction("test");
SmallVector<BasicBlock *, 1> Blocks{ getBlockByName(Func, "if.else") };
AssumptionCache AC(*Func);
CodeExtractor CE(Blocks, nullptr, false, nullptr, nullptr, &AC);
EXPECT_TRUE(CE.isEligible());
CodeExtractorAnalysisCache CEAC(*Func);
Function *Outlined = CE.extractCodeRegion(CEAC);
EXPECT_TRUE(Outlined);
EXPECT_FALSE(verifyFunction(*Outlined));
EXPECT_FALSE(verifyFunction(*Func));
EXPECT_FALSE(CE.verifyAssumptionCache(*Func, *Outlined, &AC));
}
TEST(CodeExtractor, RemoveBitcastUsesFromOuterLifetimeMarkers) {
LLVMContext Ctx;
SMDiagnostic Err;
std::unique_ptr<Module> M(parseAssemblyString(R"ir(
target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"
declare void @use(i32*)
declare void @llvm.lifetime.start.p0i8(i64, i8*)
declare void @llvm.lifetime.end.p0i8(i64, i8*)
define void @foo() {
entry:
%0 = alloca i32
br label %extract
extract:
%1 = bitcast i32* %0 to i8*
call void @llvm.lifetime.start.p0i8(i64 4, i8* %1)
call void @use(i32* %0)
br label %exit
exit:
call void @use(i32* %0)
call void @llvm.lifetime.end.p0i8(i64 4, i8* %1)
ret void
}
)ir",
Err, Ctx));
Function *Func = M->getFunction("foo");
SmallVector<BasicBlock *, 1> Blocks{getBlockByName(Func, "extract")};
CodeExtractor CE(Blocks);
EXPECT_TRUE(CE.isEligible());
CodeExtractorAnalysisCache CEAC(*Func);
SetVector<Value *> Inputs, Outputs, SinkingCands, HoistingCands;
BasicBlock *CommonExit = nullptr;
CE.findAllocas(CEAC, SinkingCands, HoistingCands, CommonExit);
CE.findInputsOutputs(Inputs, Outputs, SinkingCands);
EXPECT_EQ(Outputs.size(), 0U);
Function *Outlined = CE.extractCodeRegion(CEAC);
EXPECT_TRUE(Outlined);
EXPECT_FALSE(verifyFunction(*Outlined));
EXPECT_FALSE(verifyFunction(*Func));
}
} // end anonymous namespace