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//===- Local.cpp - Unit tests for Local -----------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "llvm/Transforms/Utils/Local.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/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());
}
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,
"define void @f() !dbg !8 {\n"
"entry:\n"
" %x = alloca i32, align 4\n"
" call void @llvm.dbg.declare(metadata i32* %x, metadata !11, metadata "
"!DIExpression()), !dbg !13\n"
" call void @llvm.dbg.declare(metadata i32* %x, metadata !11, metadata "
"!DIExpression()), !dbg !13\n"
" ret void, !dbg !14\n"
"}\n"
"declare void @llvm.dbg.declare(metadata, metadata, metadata)\n"
"!llvm.dbg.cu = !{!0}\n"
"!llvm.module.flags = !{!3, !4}\n"
"!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "
"\"clang version 6.0.0 \", isOptimized: false, runtimeVersion: 0, "
"emissionKind: FullDebug, enums: !2)\n"
"!1 = !DIFile(filename: \"t2.c\", directory: \"foo\")\n"
"!2 = !{}\n"
"!3 = !{i32 2, !\"Dwarf Version\", i32 4}\n"
"!4 = !{i32 2, !\"Debug Info Version\", i32 3}\n"
"!8 = distinct !DISubprogram(name: \"f\", scope: !1, file: !1, line: 1, "
"type: !9, isLocal: false, isDefinition: true, scopeLine: 1, "
"isOptimized: false, unit: !0, variables: !2)\n"
"!9 = !DISubroutineType(types: !10)\n"
"!10 = !{null}\n"
"!11 = !DILocalVariable(name: \"x\", scope: !8, file: !1, line: 2, type: "
"!12)\n"
"!12 = !DIBasicType(name: \"int\", size: 32, encoding: DW_ATE_signed)\n"
"!13 = !DILocation(line: 2, column: 7, scope: !8)\n"
"!14 = !DILocation(line: 3, column: 1, scope: !8)\n");
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, DII, DIB, /*Deref=*/false, /*Offset=*/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 = parseIR(
C,
"define i32 @f(i8* %str) {\n"
"entry:\n"
" br label %bb2.i\n"
"bb2.i: ; preds = %bb4.i, %entry\n"
" br i1 false, label %bb4.i, label %base2flt.exit204\n"
"bb4.i: ; preds = %bb2.i\n"
" br i1 false, label %base2flt.exit204, label %bb2.i\n"
"bb10.i196.bb7.i197_crit_edge: ; No predecessors!\n"
" br label %bb7.i197\n"
"bb7.i197: ; preds = %bb10.i196.bb7.i197_crit_edge\n"
" %.reg2mem.0 = phi i32 [ %.reg2mem.0, %bb10.i196.bb7.i197_crit_edge ]\n"
" br i1 undef, label %base2flt.exit204, label %base2flt.exit204\n"
"base2flt.exit204: ; preds = %bb7.i197, %bb7.i197, %bb2.i, %bb4.i\n"
" ret i32 0\n"
"}\n");
runWithDomTree(
*M, "f", [&](Function &F, DominatorTree *DT) {
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, DT);
}
EXPECT_TRUE(DT->verify());
});
}
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