llvm-for-llvmta/unittests/Transforms/Utils/LocalTest.cpp

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2022-04-25 10:02:23 +02:00
//===- Local.cpp - Unit tests for Local -----------------------------------===//
//
// 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/Local.h"
#include "llvm/Analysis/DomTreeUpdater.h"
#include "llvm/Analysis/PostDominators.h"
#include "llvm/Analysis/TargetTransformInfo.h"
#include "llvm/AsmParser/Parser.h"
#include "llvm/IR/BasicBlock.h"
#include "llvm/IR/DIBuilder.h"
#include "llvm/IR/IRBuilder.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/IntrinsicInst.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/IR/Verifier.h"
#include "llvm/Support/SourceMgr.h"
#include "gtest/gtest.h"
using namespace llvm;
TEST(Local, RecursivelyDeleteDeadPHINodes) {
LLVMContext C;
IRBuilder<> builder(C);
// Make blocks
BasicBlock *bb0 = BasicBlock::Create(C);
BasicBlock *bb1 = BasicBlock::Create(C);
builder.SetInsertPoint(bb0);
PHINode *phi = builder.CreatePHI(Type::getInt32Ty(C), 2);
BranchInst *br0 = builder.CreateCondBr(builder.getTrue(), bb0, bb1);
builder.SetInsertPoint(bb1);
BranchInst *br1 = builder.CreateBr(bb0);
phi->addIncoming(phi, bb0);
phi->addIncoming(phi, bb1);
// The PHI will be removed
EXPECT_TRUE(RecursivelyDeleteDeadPHINode(phi));
// Make sure the blocks only contain the branches
EXPECT_EQ(&bb0->front(), br0);
EXPECT_EQ(&bb1->front(), br1);
builder.SetInsertPoint(bb0);
phi = builder.CreatePHI(Type::getInt32Ty(C), 0);
EXPECT_TRUE(RecursivelyDeleteDeadPHINode(phi));
builder.SetInsertPoint(bb0);
phi = builder.CreatePHI(Type::getInt32Ty(C), 0);
builder.CreateAdd(phi, phi);
EXPECT_TRUE(RecursivelyDeleteDeadPHINode(phi));
bb0->dropAllReferences();
bb1->dropAllReferences();
delete bb0;
delete bb1;
}
TEST(Local, RemoveDuplicatePHINodes) {
LLVMContext C;
IRBuilder<> B(C);
std::unique_ptr<Function> F(
Function::Create(FunctionType::get(B.getVoidTy(), false),
GlobalValue::ExternalLinkage, "F"));
BasicBlock *Entry(BasicBlock::Create(C, "", F.get()));
BasicBlock *BB(BasicBlock::Create(C, "", F.get()));
BranchInst::Create(BB, Entry);
B.SetInsertPoint(BB);
AssertingVH<PHINode> P1 = B.CreatePHI(Type::getInt32Ty(C), 2);
P1->addIncoming(B.getInt32(42), Entry);
PHINode *P2 = B.CreatePHI(Type::getInt32Ty(C), 2);
P2->addIncoming(B.getInt32(42), Entry);
AssertingVH<PHINode> P3 = B.CreatePHI(Type::getInt32Ty(C), 2);
P3->addIncoming(B.getInt32(42), Entry);
P3->addIncoming(B.getInt32(23), BB);
PHINode *P4 = B.CreatePHI(Type::getInt32Ty(C), 2);
P4->addIncoming(B.getInt32(42), Entry);
P4->addIncoming(B.getInt32(23), BB);
P1->addIncoming(P3, BB);
P2->addIncoming(P4, BB);
BranchInst::Create(BB, BB);
// Verify that we can eliminate PHIs that become duplicates after chaning PHIs
// downstream.
EXPECT_TRUE(EliminateDuplicatePHINodes(BB));
EXPECT_EQ(3U, BB->size());
}
static std::unique_ptr<Module> parseIR(LLVMContext &C, const char *IR) {
SMDiagnostic Err;
std::unique_ptr<Module> Mod = parseAssemblyString(IR, Err, C);
if (!Mod)
Err.print("UtilsTests", errs());
return Mod;
}
TEST(Local, ReplaceDbgDeclare) {
LLVMContext C;
// Original C source to get debug info for a local variable:
// void f() { int x; }
std::unique_ptr<Module> M = parseIR(C,
R"(
define void @f() !dbg !8 {
entry:
%x = alloca i32, align 4
call void @llvm.dbg.declare(metadata i32* %x, metadata !11, metadata !DIExpression()), !dbg !13
call void @llvm.dbg.declare(metadata i32* %x, metadata !11, metadata !DIExpression()), !dbg !13
ret void, !dbg !14
}
declare void @llvm.dbg.declare(metadata, metadata, metadata)
!llvm.dbg.cu = !{!0}
!llvm.module.flags = !{!3, !4}
!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 6.0.0", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, enums: !2)
!1 = !DIFile(filename: "t2.c", directory: "foo")
!2 = !{}
!3 = !{i32 2, !"Dwarf Version", i32 4}
!4 = !{i32 2, !"Debug Info Version", i32 3}
!8 = distinct !DISubprogram(name: "f", scope: !1, file: !1, line: 1, type: !9, isLocal: false, isDefinition: true, scopeLine: 1, isOptimized: false, unit: !0, retainedNodes: !2)
!9 = !DISubroutineType(types: !10)
!10 = !{null}
!11 = !DILocalVariable(name: "x", scope: !8, file: !1, line: 2, type: !12)
!12 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
!13 = !DILocation(line: 2, column: 7, scope: !8)
!14 = !DILocation(line: 3, column: 1, scope: !8)
)");
auto *GV = M->getNamedValue("f");
ASSERT_TRUE(GV);
auto *F = dyn_cast<Function>(GV);
ASSERT_TRUE(F);
Instruction *Inst = &F->front().front();
auto *AI = dyn_cast<AllocaInst>(Inst);
ASSERT_TRUE(AI);
Inst = Inst->getNextNode()->getNextNode();
ASSERT_TRUE(Inst);
auto *DII = dyn_cast<DbgDeclareInst>(Inst);
ASSERT_TRUE(DII);
Value *NewBase = Constant::getNullValue(Type::getInt32PtrTy(C));
DIBuilder DIB(*M);
replaceDbgDeclare(AI, NewBase, DIB, DIExpression::ApplyOffset, 0);
// There should be exactly two dbg.declares.
int Declares = 0;
for (const Instruction &I : F->front())
if (isa<DbgDeclareInst>(I))
Declares++;
EXPECT_EQ(2, Declares);
}
/// Build the dominator tree for the function and run the Test.
static void runWithDomTree(
Module &M, StringRef FuncName,
function_ref<void(Function &F, DominatorTree *DT)> Test) {
auto *F = M.getFunction(FuncName);
ASSERT_NE(F, nullptr) << "Could not find " << FuncName;
// Compute the dominator tree for the function.
DominatorTree DT(*F);
Test(*F, &DT);
}
TEST(Local, MergeBasicBlockIntoOnlyPred) {
LLVMContext C;
std::unique_ptr<Module> M;
auto resetIR = [&]() {
M = parseIR(C,
R"(
define i32 @f(i8* %str) {
entry:
br label %bb2.i
bb2.i: ; preds = %bb4.i, %entry
br i1 false, label %bb4.i, label %base2flt.exit204
bb4.i: ; preds = %bb2.i
br i1 false, label %base2flt.exit204, label %bb2.i
bb10.i196.bb7.i197_crit_edge: ; No predecessors!
br label %bb7.i197
bb7.i197: ; preds = %bb10.i196.bb7.i197_crit_edge
%.reg2mem.0 = phi i32 [ %.reg2mem.0, %bb10.i196.bb7.i197_crit_edge ]
br i1 undef, label %base2flt.exit204, label %base2flt.exit204
base2flt.exit204: ; preds = %bb7.i197, %bb7.i197, %bb2.i, %bb4.i
ret i32 0
}
)");
};
auto resetIRReplaceEntry = [&]() {
M = parseIR(C,
R"(
define i32 @f() {
entry:
br label %bb2.i
bb2.i: ; preds = %entry
ret i32 0
}
)");
};
auto Test = [&](Function &F, DomTreeUpdater &DTU) {
for (Function::iterator I = F.begin(), E = F.end(); I != E;) {
BasicBlock *BB = &*I++;
BasicBlock *SinglePred = BB->getSinglePredecessor();
if (!SinglePred || SinglePred == BB || BB->hasAddressTaken())
continue;
BranchInst *Term = dyn_cast<BranchInst>(SinglePred->getTerminator());
if (Term && !Term->isConditional())
MergeBasicBlockIntoOnlyPred(BB, &DTU);
}
if (DTU.hasDomTree()) {
EXPECT_TRUE(DTU.getDomTree().verify());
}
if (DTU.hasPostDomTree()) {
EXPECT_TRUE(DTU.getPostDomTree().verify());
}
};
// Test MergeBasicBlockIntoOnlyPred working under Eager UpdateStrategy with
// both DT and PDT.
resetIR();
runWithDomTree(*M, "f", [&](Function &F, DominatorTree *DT) {
PostDominatorTree PDT = PostDominatorTree(F);
DomTreeUpdater DTU(*DT, PDT, DomTreeUpdater::UpdateStrategy::Eager);
Test(F, DTU);
});
// Test MergeBasicBlockIntoOnlyPred working under Eager UpdateStrategy with
// DT.
resetIR();
runWithDomTree(*M, "f", [&](Function &F, DominatorTree *DT) {
DomTreeUpdater DTU(*DT, DomTreeUpdater::UpdateStrategy::Eager);
Test(F, DTU);
});
// Test MergeBasicBlockIntoOnlyPred working under Eager UpdateStrategy with
// PDT.
resetIR();
runWithDomTree(*M, "f", [&](Function &F, DominatorTree *DT) {
PostDominatorTree PDT = PostDominatorTree(F);
DomTreeUpdater DTU(PDT, DomTreeUpdater::UpdateStrategy::Eager);
Test(F, DTU);
});
// Test MergeBasicBlockIntoOnlyPred working under Lazy UpdateStrategy with
// both DT and PDT.
resetIR();
runWithDomTree(*M, "f", [&](Function &F, DominatorTree *DT) {
PostDominatorTree PDT = PostDominatorTree(F);
DomTreeUpdater DTU(*DT, PDT, DomTreeUpdater::UpdateStrategy::Lazy);
Test(F, DTU);
});
// Test MergeBasicBlockIntoOnlyPred working under Lazy UpdateStrategy with
// PDT.
resetIR();
runWithDomTree(*M, "f", [&](Function &F, DominatorTree *DT) {
PostDominatorTree PDT = PostDominatorTree(F);
DomTreeUpdater DTU(PDT, DomTreeUpdater::UpdateStrategy::Lazy);
Test(F, DTU);
});
// Test MergeBasicBlockIntoOnlyPred working under Lazy UpdateStrategy with DT.
resetIR();
runWithDomTree(*M, "f", [&](Function &F, DominatorTree *DT) {
DomTreeUpdater DTU(*DT, DomTreeUpdater::UpdateStrategy::Lazy);
Test(F, DTU);
});
// Test MergeBasicBlockIntoOnlyPred working under Eager UpdateStrategy with
// both DT and PDT.
resetIRReplaceEntry();
runWithDomTree(*M, "f", [&](Function &F, DominatorTree *DT) {
PostDominatorTree PDT = PostDominatorTree(F);
DomTreeUpdater DTU(*DT, PDT, DomTreeUpdater::UpdateStrategy::Eager);
Test(F, DTU);
});
// Test MergeBasicBlockIntoOnlyPred working under Eager UpdateStrategy with
// DT.
resetIRReplaceEntry();
runWithDomTree(*M, "f", [&](Function &F, DominatorTree *DT) {
DomTreeUpdater DTU(*DT, DomTreeUpdater::UpdateStrategy::Eager);
Test(F, DTU);
});
// Test MergeBasicBlockIntoOnlyPred working under Eager UpdateStrategy with
// PDT.
resetIRReplaceEntry();
runWithDomTree(*M, "f", [&](Function &F, DominatorTree *DT) {
PostDominatorTree PDT = PostDominatorTree(F);
DomTreeUpdater DTU(PDT, DomTreeUpdater::UpdateStrategy::Eager);
Test(F, DTU);
});
// Test MergeBasicBlockIntoOnlyPred working under Lazy UpdateStrategy with
// both DT and PDT.
resetIRReplaceEntry();
runWithDomTree(*M, "f", [&](Function &F, DominatorTree *DT) {
PostDominatorTree PDT = PostDominatorTree(F);
DomTreeUpdater DTU(*DT, PDT, DomTreeUpdater::UpdateStrategy::Lazy);
Test(F, DTU);
});
// Test MergeBasicBlockIntoOnlyPred working under Lazy UpdateStrategy with
// PDT.
resetIRReplaceEntry();
runWithDomTree(*M, "f", [&](Function &F, DominatorTree *DT) {
PostDominatorTree PDT = PostDominatorTree(F);
DomTreeUpdater DTU(PDT, DomTreeUpdater::UpdateStrategy::Lazy);
Test(F, DTU);
});
// Test MergeBasicBlockIntoOnlyPred working under Lazy UpdateStrategy with DT.
resetIRReplaceEntry();
runWithDomTree(*M, "f", [&](Function &F, DominatorTree *DT) {
DomTreeUpdater DTU(*DT, DomTreeUpdater::UpdateStrategy::Lazy);
Test(F, DTU);
});
}
TEST(Local, ConstantFoldTerminator) {
LLVMContext C;
std::unique_ptr<Module> M = parseIR(C,
R"(
define void @br_same_dest() {
entry:
br i1 false, label %bb0, label %bb0
bb0:
ret void
}
define void @br_different_dest() {
entry:
br i1 true, label %bb0, label %bb1
bb0:
br label %exit
bb1:
br label %exit
exit:
ret void
}
define void @switch_2_different_dest() {
entry:
switch i32 0, label %default [ i32 0, label %bb0 ]
default:
ret void
bb0:
ret void
}
define void @switch_2_different_dest_default() {
entry:
switch i32 1, label %default [ i32 0, label %bb0 ]
default:
ret void
bb0:
ret void
}
define void @switch_3_different_dest() {
entry:
switch i32 0, label %default [ i32 0, label %bb0
i32 1, label %bb1 ]
default:
ret void
bb0:
ret void
bb1:
ret void
}
define void @switch_variable_2_default_dest(i32 %arg) {
entry:
switch i32 %arg, label %default [ i32 0, label %default ]
default:
ret void
}
define void @switch_constant_2_default_dest() {
entry:
switch i32 1, label %default [ i32 0, label %default ]
default:
ret void
}
define void @switch_constant_3_repeated_dest() {
entry:
switch i32 0, label %default [ i32 0, label %bb0
i32 1, label %bb0 ]
bb0:
ret void
default:
ret void
}
define void @indirectbr() {
entry:
indirectbr i8* blockaddress(@indirectbr, %bb0), [label %bb0, label %bb1]
bb0:
ret void
bb1:
ret void
}
define void @indirectbr_repeated() {
entry:
indirectbr i8* blockaddress(@indirectbr_repeated, %bb0), [label %bb0, label %bb0]
bb0:
ret void
}
define void @indirectbr_unreachable() {
entry:
indirectbr i8* blockaddress(@indirectbr_unreachable, %bb0), [label %bb1]
bb0:
ret void
bb1:
ret void
}
)");
auto CFAllTerminatorsEager = [&](Function &F, DominatorTree *DT) {
PostDominatorTree PDT = PostDominatorTree(F);
DomTreeUpdater DTU(*DT, PDT, DomTreeUpdater::UpdateStrategy::Eager);
for (Function::iterator I = F.begin(), E = F.end(); I != E;) {
BasicBlock *BB = &*I++;
ConstantFoldTerminator(BB, true, nullptr, &DTU);
}
EXPECT_TRUE(DTU.getDomTree().verify());
EXPECT_TRUE(DTU.getPostDomTree().verify());
};
auto CFAllTerminatorsLazy = [&](Function &F, DominatorTree *DT) {
PostDominatorTree PDT = PostDominatorTree(F);
DomTreeUpdater DTU(*DT, PDT, DomTreeUpdater::UpdateStrategy::Lazy);
for (Function::iterator I = F.begin(), E = F.end(); I != E;) {
BasicBlock *BB = &*I++;
ConstantFoldTerminator(BB, true, nullptr, &DTU);
}
EXPECT_TRUE(DTU.getDomTree().verify());
EXPECT_TRUE(DTU.getPostDomTree().verify());
};
// Test ConstantFoldTerminator under Eager UpdateStrategy.
runWithDomTree(*M, "br_same_dest", CFAllTerminatorsEager);
runWithDomTree(*M, "br_different_dest", CFAllTerminatorsEager);
runWithDomTree(*M, "switch_2_different_dest", CFAllTerminatorsEager);
runWithDomTree(*M, "switch_2_different_dest_default", CFAllTerminatorsEager);
runWithDomTree(*M, "switch_3_different_dest", CFAllTerminatorsEager);
runWithDomTree(*M, "switch_variable_2_default_dest", CFAllTerminatorsEager);
runWithDomTree(*M, "switch_constant_2_default_dest", CFAllTerminatorsEager);
runWithDomTree(*M, "switch_constant_3_repeated_dest", CFAllTerminatorsEager);
runWithDomTree(*M, "indirectbr", CFAllTerminatorsEager);
runWithDomTree(*M, "indirectbr_repeated", CFAllTerminatorsEager);
runWithDomTree(*M, "indirectbr_unreachable", CFAllTerminatorsEager);
// Test ConstantFoldTerminator under Lazy UpdateStrategy.
runWithDomTree(*M, "br_same_dest", CFAllTerminatorsLazy);
runWithDomTree(*M, "br_different_dest", CFAllTerminatorsLazy);
runWithDomTree(*M, "switch_2_different_dest", CFAllTerminatorsLazy);
runWithDomTree(*M, "switch_2_different_dest_default", CFAllTerminatorsLazy);
runWithDomTree(*M, "switch_3_different_dest", CFAllTerminatorsLazy);
runWithDomTree(*M, "switch_variable_2_default_dest", CFAllTerminatorsLazy);
runWithDomTree(*M, "switch_constant_2_default_dest", CFAllTerminatorsLazy);
runWithDomTree(*M, "switch_constant_3_repeated_dest", CFAllTerminatorsLazy);
runWithDomTree(*M, "indirectbr", CFAllTerminatorsLazy);
runWithDomTree(*M, "indirectbr_repeated", CFAllTerminatorsLazy);
runWithDomTree(*M, "indirectbr_unreachable", CFAllTerminatorsLazy);
}
struct SalvageDebugInfoTest : ::testing::Test {
LLVMContext C;
std::unique_ptr<Module> M;
Function *F = nullptr;
void SetUp() override {
M = parseIR(C,
R"(
define void @f() !dbg !8 {
entry:
%x = add i32 0, 1
%y = add i32 %x, 2
call void @llvm.dbg.value(metadata i32 %x, metadata !11, metadata !DIExpression()), !dbg !13
call void @llvm.dbg.value(metadata i32 %y, metadata !11, metadata !DIExpression()), !dbg !13
ret void, !dbg !14
}
declare void @llvm.dbg.value(metadata, metadata, metadata)
!llvm.dbg.cu = !{!0}
!llvm.module.flags = !{!3, !4}
!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 6.0.0", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, enums: !2)
!1 = !DIFile(filename: "t2.c", directory: "foo")
!2 = !{}
!3 = !{i32 2, !"Dwarf Version", i32 4}
!4 = !{i32 2, !"Debug Info Version", i32 3}
!8 = distinct !DISubprogram(name: "f", scope: !1, file: !1, line: 1, type: !9, isLocal: false, isDefinition: true, scopeLine: 1, isOptimized: false, unit: !0, retainedNodes: !2)
!9 = !DISubroutineType(types: !10)
!10 = !{null}
!11 = !DILocalVariable(name: "x", scope: !8, file: !1, line: 2, type: !12)
!12 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
!13 = !DILocation(line: 2, column: 7, scope: !8)
!14 = !DILocation(line: 3, column: 1, scope: !8)
)");
auto *GV = M->getNamedValue("f");
ASSERT_TRUE(GV);
F = dyn_cast<Function>(GV);
ASSERT_TRUE(F);
}
bool doesDebugValueDescribeX(const DbgValueInst &DI) {
const auto &CI = *cast<ConstantInt>(DI.getValue());
if (CI.isZero())
return DI.getExpression()->getElements().equals(
{dwarf::DW_OP_plus_uconst, 1, dwarf::DW_OP_stack_value});
else if (CI.isOneValue())
return DI.getExpression()->getElements().empty();
return false;
}
bool doesDebugValueDescribeY(const DbgValueInst &DI) {
const auto &CI = *cast<ConstantInt>(DI.getValue());
if (CI.isZero())
return DI.getExpression()->getElements().equals(
{dwarf::DW_OP_plus_uconst, 1, dwarf::DW_OP_plus_uconst, 2,
dwarf::DW_OP_stack_value});
else if (CI.isOneValue())
return DI.getExpression()->getElements().equals(
{dwarf::DW_OP_plus_uconst, 2, dwarf::DW_OP_stack_value});
return false;
}
void verifyDebugValuesAreSalvaged() {
// Check that the debug values for %x and %y are preserved.
bool FoundX = false;
bool FoundY = false;
for (const Instruction &I : F->front()) {
auto DI = dyn_cast<DbgValueInst>(&I);
if (!DI) {
// The function should only contain debug values and a terminator.
ASSERT_TRUE(I.isTerminator());
continue;
}
EXPECT_EQ(DI->getVariable()->getName(), "x");
FoundX |= doesDebugValueDescribeX(*DI);
FoundY |= doesDebugValueDescribeY(*DI);
}
ASSERT_TRUE(FoundX);
ASSERT_TRUE(FoundY);
}
};
TEST_F(SalvageDebugInfoTest, RecursiveInstDeletion) {
Instruction *Inst = &F->front().front();
Inst = Inst->getNextNode(); // Get %y = add ...
ASSERT_TRUE(Inst);
bool Deleted = RecursivelyDeleteTriviallyDeadInstructions(Inst);
ASSERT_TRUE(Deleted);
verifyDebugValuesAreSalvaged();
}
TEST_F(SalvageDebugInfoTest, RecursiveBlockSimplification) {
BasicBlock *BB = &F->front();
ASSERT_TRUE(BB);
bool Deleted = SimplifyInstructionsInBlock(BB);
ASSERT_TRUE(Deleted);
verifyDebugValuesAreSalvaged();
}
TEST(Local, ChangeToUnreachable) {
LLVMContext Ctx;
std::unique_ptr<Module> M = parseIR(Ctx,
R"(
define internal void @foo() !dbg !6 {
entry:
ret void, !dbg !8
}
!llvm.dbg.cu = !{!0}
!llvm.debugify = !{!3, !4}
!llvm.module.flags = !{!5}
!0 = distinct !DICompileUnit(language: DW_LANG_C, file: !1, producer: "debugify", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2)
!1 = !DIFile(filename: "test.ll", directory: "/")
!2 = !{}
!3 = !{i32 1}
!4 = !{i32 0}
!5 = !{i32 2, !"Debug Info Version", i32 3}
!6 = distinct !DISubprogram(name: "foo", linkageName: "foo", scope: null, file: !1, line: 1, type: !7, isLocal: true, isDefinition: true, scopeLine: 1, isOptimized: true, unit: !0, retainedNodes: !2)
!7 = !DISubroutineType(types: !2)
!8 = !DILocation(line: 1, column: 1, scope: !6)
)");
bool BrokenDebugInfo = true;
verifyModule(*M, &errs(), &BrokenDebugInfo);
ASSERT_FALSE(BrokenDebugInfo);
Function &F = *cast<Function>(M->getNamedValue("foo"));
BasicBlock &BB = F.front();
Instruction &A = BB.front();
DebugLoc DLA = A.getDebugLoc();
ASSERT_TRUE(isa<ReturnInst>(&A));
// One instruction should be affected.
EXPECT_EQ(changeToUnreachable(&A, /*UseLLVMTrap*/false), 1U);
Instruction &B = BB.front();
// There should be an uncreachable instruction.
ASSERT_TRUE(isa<UnreachableInst>(&B));
DebugLoc DLB = B.getDebugLoc();
EXPECT_EQ(DLA, DLB);
}
TEST(Local, ReplaceAllDbgUsesWith) {
using namespace llvm::dwarf;
LLVMContext Ctx;
// Note: The datalayout simulates Darwin/x86_64.
std::unique_ptr<Module> M = parseIR(Ctx,
R"(
target datalayout = "e-m:o-i63:64-f80:128-n8:16:32:64-S128"
declare i32 @escape(i32)
define void @f() !dbg !6 {
entry:
%a = add i32 0, 1, !dbg !15
call void @llvm.dbg.value(metadata i32 %a, metadata !9, metadata !DIExpression()), !dbg !15
%b = add i64 0, 1, !dbg !16
call void @llvm.dbg.value(metadata i64 %b, metadata !11, metadata !DIExpression()), !dbg !16
call void @llvm.dbg.value(metadata i64 %b, metadata !11, metadata !DIExpression(DW_OP_lit0, DW_OP_mul)), !dbg !16
call void @llvm.dbg.value(metadata i64 %b, metadata !11, metadata !DIExpression(DW_OP_lit0, DW_OP_mul, DW_OP_stack_value)), !dbg !16
call void @llvm.dbg.value(metadata i64 %b, metadata !11, metadata !DIExpression(DW_OP_LLVM_fragment, 0, 8)), !dbg !16
call void @llvm.dbg.value(metadata i64 %b, metadata !11, metadata !DIExpression(DW_OP_lit0, DW_OP_mul, DW_OP_LLVM_fragment, 0, 8)), !dbg !16
call void @llvm.dbg.value(metadata i64 %b, metadata !11, metadata !DIExpression(DW_OP_lit0, DW_OP_mul, DW_OP_stack_value, DW_OP_LLVM_fragment, 0, 8)), !dbg !16
%c = inttoptr i64 0 to i64*, !dbg !17
call void @llvm.dbg.declare(metadata i64* %c, metadata !13, metadata !DIExpression()), !dbg !17
%d = inttoptr i64 0 to i32*, !dbg !18
call void @llvm.dbg.addr(metadata i32* %d, metadata !20, metadata !DIExpression()), !dbg !18
%e = add <2 x i16> zeroinitializer, zeroinitializer
call void @llvm.dbg.value(metadata <2 x i16> %e, metadata !14, metadata !DIExpression()), !dbg !18
%f = call i32 @escape(i32 0)
call void @llvm.dbg.value(metadata i32 %f, metadata !9, metadata !DIExpression()), !dbg !15
%barrier = call i32 @escape(i32 0)
%g = call i32 @escape(i32 %f)
call void @llvm.dbg.value(metadata i32 %g, metadata !9, metadata !DIExpression()), !dbg !15
ret void, !dbg !19
}
declare void @llvm.dbg.addr(metadata, metadata, metadata)
declare void @llvm.dbg.declare(metadata, metadata, metadata)
declare void @llvm.dbg.value(metadata, metadata, metadata)
!llvm.dbg.cu = !{!0}
!llvm.module.flags = !{!5}
!0 = distinct !DICompileUnit(language: DW_LANG_C, file: !1, producer: "debugify", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2)
!1 = !DIFile(filename: "/Users/vsk/Desktop/foo.ll", directory: "/")
!2 = !{}
!5 = !{i32 2, !"Debug Info Version", i32 3}
!6 = distinct !DISubprogram(name: "f", linkageName: "f", scope: null, file: !1, line: 1, type: !7, isLocal: false, isDefinition: true, scopeLine: 1, isOptimized: true, unit: !0, retainedNodes: !8)
!7 = !DISubroutineType(types: !2)
!8 = !{!9, !11, !13, !14}
!9 = !DILocalVariable(name: "1", scope: !6, file: !1, line: 1, type: !10)
!10 = !DIBasicType(name: "ty32", size: 32, encoding: DW_ATE_signed)
!11 = !DILocalVariable(name: "2", scope: !6, file: !1, line: 2, type: !12)
!12 = !DIBasicType(name: "ty64", size: 64, encoding: DW_ATE_signed)
!13 = !DILocalVariable(name: "3", scope: !6, file: !1, line: 3, type: !12)
!14 = !DILocalVariable(name: "4", scope: !6, file: !1, line: 4, type: !10)
!15 = !DILocation(line: 1, column: 1, scope: !6)
!16 = !DILocation(line: 2, column: 1, scope: !6)
!17 = !DILocation(line: 3, column: 1, scope: !6)
!18 = !DILocation(line: 4, column: 1, scope: !6)
!19 = !DILocation(line: 5, column: 1, scope: !6)
!20 = !DILocalVariable(name: "5", scope: !6, file: !1, line: 5, type: !10)
)");
bool BrokenDebugInfo = true;
verifyModule(*M, &errs(), &BrokenDebugInfo);
ASSERT_FALSE(BrokenDebugInfo);
Function &F = *cast<Function>(M->getNamedValue("f"));
DominatorTree DT{F};
BasicBlock &BB = F.front();
Instruction &A = BB.front();
Instruction &B = *A.getNextNonDebugInstruction();
Instruction &C = *B.getNextNonDebugInstruction();
Instruction &D = *C.getNextNonDebugInstruction();
Instruction &E = *D.getNextNonDebugInstruction();
Instruction &F_ = *E.getNextNonDebugInstruction();
Instruction &Barrier = *F_.getNextNonDebugInstruction();
Instruction &G = *Barrier.getNextNonDebugInstruction();
// Simulate i32 <-> i64* conversion. Expect no updates: the datalayout says
// pointers are 64 bits, so the conversion would be lossy.
EXPECT_FALSE(replaceAllDbgUsesWith(A, C, C, DT));
EXPECT_FALSE(replaceAllDbgUsesWith(C, A, A, DT));
// Simulate i32 <-> <2 x i16> conversion. This is unsupported.
EXPECT_FALSE(replaceAllDbgUsesWith(E, A, A, DT));
EXPECT_FALSE(replaceAllDbgUsesWith(A, E, E, DT));
// Simulate i32* <-> i64* conversion.
EXPECT_TRUE(replaceAllDbgUsesWith(D, C, C, DT));
SmallVector<DbgVariableIntrinsic *, 2> CDbgVals;
findDbgUsers(CDbgVals, &C);
EXPECT_EQ(2U, CDbgVals.size());
EXPECT_TRUE(any_of(CDbgVals, [](DbgVariableIntrinsic *DII) {
return isa<DbgAddrIntrinsic>(DII);
}));
EXPECT_TRUE(any_of(CDbgVals, [](DbgVariableIntrinsic *DII) {
return isa<DbgDeclareInst>(DII);
}));
EXPECT_TRUE(replaceAllDbgUsesWith(C, D, D, DT));
SmallVector<DbgVariableIntrinsic *, 2> DDbgVals;
findDbgUsers(DDbgVals, &D);
EXPECT_EQ(2U, DDbgVals.size());
EXPECT_TRUE(any_of(DDbgVals, [](DbgVariableIntrinsic *DII) {
return isa<DbgAddrIntrinsic>(DII);
}));
EXPECT_TRUE(any_of(DDbgVals, [](DbgVariableIntrinsic *DII) {
return isa<DbgDeclareInst>(DII);
}));
// Introduce a use-before-def. Check that the dbg.value for %a is salvaged.
EXPECT_TRUE(replaceAllDbgUsesWith(A, F_, F_, DT));
auto *ADbgVal = cast<DbgValueInst>(A.getNextNode());
EXPECT_EQ(ConstantInt::get(A.getType(), 0), ADbgVal->getVariableLocation());
// Introduce a use-before-def. Check that the dbg.values for %f become undef.
EXPECT_TRUE(replaceAllDbgUsesWith(F_, G, G, DT));
auto *FDbgVal = cast<DbgValueInst>(F_.getNextNode());
EXPECT_TRUE(isa<UndefValue>(FDbgVal->getVariableLocation()));
SmallVector<DbgValueInst *, 1> FDbgVals;
findDbgValues(FDbgVals, &F_);
EXPECT_EQ(0U, FDbgVals.size());
// Simulate i32 -> i64 conversion to test sign-extension. Here are some
// interesting cases to handle:
// 1) debug user has empty DIExpression
// 2) debug user has non-empty, non-stack-value'd DIExpression
// 3) debug user has non-empty, stack-value'd DIExpression
// 4-6) like (1-3), but with a fragment
EXPECT_TRUE(replaceAllDbgUsesWith(B, A, A, DT));
SmallVector<DbgValueInst *, 8> ADbgVals;
findDbgValues(ADbgVals, &A);
EXPECT_EQ(6U, ADbgVals.size());
// Check that %a has a dbg.value with a DIExpression matching \p Ops.
auto hasADbgVal = [&](ArrayRef<uint64_t> Ops) {
return any_of(ADbgVals, [&](DbgValueInst *DVI) {
assert(DVI->getVariable()->getName() == "2");
return DVI->getExpression()->getElements() == Ops;
});
};
// Case 1: The original expr is empty, so no deref is needed.
EXPECT_TRUE(hasADbgVal({DW_OP_LLVM_convert, 32, DW_ATE_signed,
DW_OP_LLVM_convert, 64, DW_ATE_signed,
DW_OP_stack_value}));
// Case 2: Perform an address calculation with the original expr, deref it,
// then sign-extend the result.
EXPECT_TRUE(hasADbgVal({DW_OP_lit0, DW_OP_mul, DW_OP_deref,
DW_OP_LLVM_convert, 32, DW_ATE_signed,
DW_OP_LLVM_convert, 64, DW_ATE_signed,
DW_OP_stack_value}));
// Case 3: Insert the sign-extension logic before the DW_OP_stack_value.
EXPECT_TRUE(hasADbgVal({DW_OP_lit0, DW_OP_mul, DW_OP_LLVM_convert, 32,
DW_ATE_signed, DW_OP_LLVM_convert, 64, DW_ATE_signed,
DW_OP_stack_value}));
// Cases 4-6: Just like cases 1-3, but preserve the fragment at the end.
EXPECT_TRUE(hasADbgVal({DW_OP_LLVM_convert, 32, DW_ATE_signed,
DW_OP_LLVM_convert, 64, DW_ATE_signed,
DW_OP_stack_value, DW_OP_LLVM_fragment, 0, 8}));
EXPECT_TRUE(hasADbgVal({DW_OP_lit0, DW_OP_mul, DW_OP_deref,
DW_OP_LLVM_convert, 32, DW_ATE_signed,
DW_OP_LLVM_convert, 64, DW_ATE_signed,
DW_OP_stack_value, DW_OP_LLVM_fragment, 0, 8}));
EXPECT_TRUE(hasADbgVal({DW_OP_lit0, DW_OP_mul, DW_OP_LLVM_convert, 32,
DW_ATE_signed, DW_OP_LLVM_convert, 64, DW_ATE_signed,
DW_OP_stack_value, DW_OP_LLVM_fragment, 0, 8}));
verifyModule(*M, &errs(), &BrokenDebugInfo);
ASSERT_FALSE(BrokenDebugInfo);
}
TEST(Local, RemoveUnreachableBlocks) {
LLVMContext C;
std::unique_ptr<Module> M = parseIR(C,
R"(
define void @br_simple() {
entry:
br label %bb0
bb0:
ret void
bb1:
ret void
}
define void @br_self_loop() {
entry:
br label %bb0
bb0:
br i1 true, label %bb1, label %bb0
bb1:
br i1 true, label %bb0, label %bb2
bb2:
br label %bb2
}
define void @br_constant() {
entry:
br label %bb0
bb0:
br i1 true, label %bb1, label %bb2
bb1:
br i1 true, label %bb0, label %bb2
bb2:
br label %bb2
}
define void @br_loop() {
entry:
br label %bb0
bb0:
br label %bb0
bb1:
br label %bb2
bb2:
br label %bb1
}
declare i32 @__gxx_personality_v0(...)
define void @invoke_terminator() personality i8* bitcast (i32 (...)* @__gxx_personality_v0 to i8*) {
entry:
br i1 undef, label %invoke.block, label %exit
invoke.block:
%cond = invoke zeroext i1 @invokable()
to label %continue.block unwind label %lpad.block
continue.block:
br i1 %cond, label %if.then, label %if.end
if.then:
unreachable
if.end:
unreachable
lpad.block:
%lp = landingpad { i8*, i32 }
catch i8* null
br label %exit
exit:
ret void
}
declare i1 @invokable()
)");
auto runEager = [&](Function &F, DominatorTree *DT) {
PostDominatorTree PDT = PostDominatorTree(F);
DomTreeUpdater DTU(*DT, PDT, DomTreeUpdater::UpdateStrategy::Eager);
removeUnreachableBlocks(F, &DTU);
EXPECT_TRUE(DTU.getDomTree().verify());
EXPECT_TRUE(DTU.getPostDomTree().verify());
};
auto runLazy = [&](Function &F, DominatorTree *DT) {
PostDominatorTree PDT = PostDominatorTree(F);
DomTreeUpdater DTU(*DT, PDT, DomTreeUpdater::UpdateStrategy::Lazy);
removeUnreachableBlocks(F, &DTU);
EXPECT_TRUE(DTU.getDomTree().verify());
EXPECT_TRUE(DTU.getPostDomTree().verify());
};
// Test removeUnreachableBlocks under Eager UpdateStrategy.
runWithDomTree(*M, "br_simple", runEager);
runWithDomTree(*M, "br_self_loop", runEager);
runWithDomTree(*M, "br_constant", runEager);
runWithDomTree(*M, "br_loop", runEager);
runWithDomTree(*M, "invoke_terminator", runEager);
// Test removeUnreachableBlocks under Lazy UpdateStrategy.
runWithDomTree(*M, "br_simple", runLazy);
runWithDomTree(*M, "br_self_loop", runLazy);
runWithDomTree(*M, "br_constant", runLazy);
runWithDomTree(*M, "br_loop", runLazy);
runWithDomTree(*M, "invoke_terminator", runLazy);
M = parseIR(C,
R"(
define void @f() {
entry:
ret void
bb0:
ret void
}
)");
auto checkRUBlocksRetVal = [&](Function &F, DominatorTree *DT) {
DomTreeUpdater DTU(DT, DomTreeUpdater::UpdateStrategy::Lazy);
EXPECT_TRUE(removeUnreachableBlocks(F, &DTU));
EXPECT_FALSE(removeUnreachableBlocks(F, &DTU));
EXPECT_TRUE(DTU.getDomTree().verify());
};
runWithDomTree(*M, "f", checkRUBlocksRetVal);
}
TEST(Local, SimplifyCFGWithNullAC) {
LLVMContext Ctx;
std::unique_ptr<Module> M = parseIR(Ctx, R"(
declare void @true_path()
declare void @false_path()
declare void @llvm.assume(i1 %cond);
define i32 @foo(i1, i32) {
entry:
%cmp = icmp sgt i32 %1, 0
br i1 %cmp, label %if.bb1, label %then.bb1
if.bb1:
call void @true_path()
br label %test.bb
then.bb1:
call void @false_path()
br label %test.bb
test.bb:
%phi = phi i1 [1, %if.bb1], [%0, %then.bb1]
call void @llvm.assume(i1 %0)
br i1 %phi, label %if.bb2, label %then.bb2
if.bb2:
ret i32 %1
then.bb2:
ret i32 0
}
)");
Function &F = *cast<Function>(M->getNamedValue("foo"));
TargetTransformInfo TTI(M->getDataLayout());
SimplifyCFGOptions Options{};
Options.setAssumptionCache(nullptr);
// Obtain BasicBlock of interest to this test, %test.bb.
BasicBlock *TestBB = nullptr;
for (BasicBlock &BB : F) {
if (BB.getName().equals("test.bb")) {
TestBB = &BB;
break;
}
}
ASSERT_TRUE(TestBB);
DominatorTree DT(F);
DomTreeUpdater DTU(DT, DomTreeUpdater::UpdateStrategy::Eager);
// %test.bb is expected to be simplified by FoldCondBranchOnPHI.
EXPECT_TRUE(simplifyCFG(TestBB, TTI,
RequireAndPreserveDomTree ? &DTU : nullptr, Options));
}
TEST(Local, CanReplaceOperandWithVariable) {
LLVMContext Ctx;
Module M("test_module", Ctx);
IRBuilder<> B(Ctx);
FunctionType *FnType =
FunctionType::get(Type::getVoidTy(Ctx), {}, false);
FunctionType *VarArgFnType =
FunctionType::get(Type::getVoidTy(Ctx), {B.getInt32Ty()}, true);
Function *TestBody = Function::Create(FnType, GlobalValue::ExternalLinkage,
0, "", &M);
BasicBlock *BB0 = BasicBlock::Create(Ctx, "", TestBody);
B.SetInsertPoint(BB0);
FunctionCallee Intrin = M.getOrInsertFunction("llvm.foo", FnType);
FunctionCallee Func = M.getOrInsertFunction("foo", FnType);
FunctionCallee VarArgFunc
= M.getOrInsertFunction("foo.vararg", VarArgFnType);
FunctionCallee VarArgIntrin
= M.getOrInsertFunction("llvm.foo.vararg", VarArgFnType);
auto *CallToIntrin = B.CreateCall(Intrin);
auto *CallToFunc = B.CreateCall(Func);
// Test if it's valid to replace the callee operand.
EXPECT_FALSE(canReplaceOperandWithVariable(CallToIntrin, 0));
EXPECT_TRUE(canReplaceOperandWithVariable(CallToFunc, 0));
// That it's invalid to replace an argument in the variadic argument list for
// an intrinsic, but OK for a normal function.
auto *CallToVarArgFunc = B.CreateCall(
VarArgFunc, {B.getInt32(0), B.getInt32(1), B.getInt32(2)});
EXPECT_TRUE(canReplaceOperandWithVariable(CallToVarArgFunc, 0));
EXPECT_TRUE(canReplaceOperandWithVariable(CallToVarArgFunc, 1));
EXPECT_TRUE(canReplaceOperandWithVariable(CallToVarArgFunc, 2));
EXPECT_TRUE(canReplaceOperandWithVariable(CallToVarArgFunc, 3));
auto *CallToVarArgIntrin = B.CreateCall(
VarArgIntrin, {B.getInt32(0), B.getInt32(1), B.getInt32(2)});
EXPECT_TRUE(canReplaceOperandWithVariable(CallToVarArgIntrin, 0));
EXPECT_FALSE(canReplaceOperandWithVariable(CallToVarArgIntrin, 1));
EXPECT_FALSE(canReplaceOperandWithVariable(CallToVarArgIntrin, 2));
EXPECT_FALSE(canReplaceOperandWithVariable(CallToVarArgIntrin, 3));
// Test that it's invalid to replace gcroot operands, even though it can't use
// immarg.
Type *PtrPtr = B.getInt8Ty()->getPointerTo(0);
Value *Alloca = B.CreateAlloca(PtrPtr, (unsigned)0);
CallInst *GCRoot = B.CreateIntrinsic(Intrinsic::gcroot, {},
{Alloca, Constant::getNullValue(PtrPtr)});
EXPECT_TRUE(canReplaceOperandWithVariable(GCRoot, 0)); // Alloca
EXPECT_FALSE(canReplaceOperandWithVariable(GCRoot, 1));
EXPECT_FALSE(canReplaceOperandWithVariable(GCRoot, 2));
BB0->dropAllReferences();
}