From 3076cc398d663d7b17ef848c58282d794a7f27c6 Mon Sep 17 00:00:00 2001 From: Wei Mi Date: Thu, 15 Sep 2016 04:06:44 +0000 Subject: [PATCH] Add a C++ unittest to test the fix for PR30213. The test exercises the branch in scev expansion when the value in ValueOffsetPair is a ptr and the offset is not divisible by the elem type size of value. Differential Revision: https://reviews.llvm.org/D24088 llvm-svn: 281575 --- llvm/unittests/Analysis/ScalarEvolutionTest.cpp | 65 +++++++++++++++++++++++++ 1 file changed, 65 insertions(+) diff --git a/llvm/unittests/Analysis/ScalarEvolutionTest.cpp b/llvm/unittests/Analysis/ScalarEvolutionTest.cpp index c4cd74f..0bc99a3 100644 --- a/llvm/unittests/Analysis/ScalarEvolutionTest.cpp +++ b/llvm/unittests/Analysis/ScalarEvolutionTest.cpp @@ -7,6 +7,7 @@ // //===----------------------------------------------------------------------===// +#include "llvm/Analysis/ScalarEvolutionExpander.h" #include "llvm/Analysis/ScalarEvolutionExpressions.h" #include "llvm/Analysis/AssumptionCache.h" #include "llvm/Analysis/LoopInfo.h" @@ -264,5 +265,69 @@ TEST_F(ScalarEvolutionsTest, SimplifiedPHI) { EXPECT_EQ(S1, S2); } +TEST_F(ScalarEvolutionsTest, ExpandPtrTypeSCEV) { + // It is to test the fix for PR30213. It exercises the branch in scev + // expansion when the value in ValueOffsetPair is a ptr and the offset + // is not divisible by the elem type size of value. + auto *I8Ty = Type::getInt8Ty(Context); + auto *I8PtrTy = Type::getInt8PtrTy(Context); + auto *I32Ty = Type::getInt32Ty(Context); + auto *I32PtrTy = Type::getInt32PtrTy(Context); + FunctionType *FTy = + FunctionType::get(Type::getVoidTy(Context), std::vector(), false); + Function *F = cast(M.getOrInsertFunction("f", FTy)); + BasicBlock *EntryBB = BasicBlock::Create(Context, "entry", F); + BasicBlock *LoopBB = BasicBlock::Create(Context, "loop", F); + BasicBlock *ExitBB = BasicBlock::Create(Context, "exit", F); + BranchInst::Create(LoopBB, EntryBB); + ReturnInst::Create(Context, nullptr, ExitBB); + + // loop: ; preds = %loop, %entry + // %alloca = alloca i32 + // %gep0 = getelementptr i32, i32* %alloca, i32 1 + // %bitcast1 = bitcast i32* %gep0 to i8* + // %gep1 = getelementptr i8, i8* %bitcast1, i32 1 + // %gep2 = getelementptr i8, i8* undef, i32 1 + // %cmp = icmp ult i8* undef, %bitcast1 + // %select = select i1 %cmp, i8* %gep1, i8* %gep2 + // %bitcast2 = bitcast i8* %select to i32* + // br i1 undef, label %loop, label %exit + + BranchInst *Br = BranchInst::Create( + LoopBB, ExitBB, UndefValue::get(Type::getInt1Ty(Context)), LoopBB); + AllocaInst *Alloca = new AllocaInst(I32Ty, "alloca", Br); + ConstantInt *Ci32 = ConstantInt::get(Context, APInt(32, 1)); + GetElementPtrInst *Gep0 = + GetElementPtrInst::Create(I32Ty, Alloca, Ci32, "gep0", Br); + CastInst *CastA = + CastInst::CreateBitOrPointerCast(Gep0, I8PtrTy, "bitcast1", Br); + GetElementPtrInst *Gep1 = + GetElementPtrInst::Create(I8Ty, CastA, Ci32, "gep1", Br); + GetElementPtrInst *Gep2 = GetElementPtrInst::Create( + I8Ty, UndefValue::get(I8PtrTy), Ci32, "gep2", Br); + CmpInst *Cmp = CmpInst::Create(Instruction::ICmp, CmpInst::ICMP_ULT, + UndefValue::get(I8PtrTy), CastA, "cmp", Br); + SelectInst *Sel = SelectInst::Create(Cmp, Gep1, Gep2, "select", Br); + CastInst *CastB = + CastInst::CreateBitOrPointerCast(Sel, I32PtrTy, "bitcast2", Br); + + ScalarEvolution SE = buildSE(*F); + auto *S = SE.getSCEV(CastB); + SCEVExpander Exp(SE, M.getDataLayout(), "expander"); + Value *V = + Exp.expandCodeFor(cast(S)->getOperand(1), nullptr, Br); + + // Expect the expansion code contains: + // %0 = bitcast i32* %bitcast2 to i8* + // %uglygep = getelementptr i8, i8* %0, i64 -1 + // %1 = bitcast i8* %uglygep to i32* + EXPECT_TRUE(isa(V)); + Instruction *Gep = cast(V)->getPrevNode(); + EXPECT_TRUE(isa(Gep)); + EXPECT_TRUE(isa(Gep->getOperand(1))); + EXPECT_EQ(cast(Gep->getOperand(1))->getSExtValue(), -1); + EXPECT_TRUE(isa(Gep->getPrevNode())); +} + } // end anonymous namespace } // end namespace llvm -- 2.7.4