diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp --- a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp @@ -4986,7 +4986,7 @@ return foldICmpWithZextOrSext(ICmp); } -static bool isNeutralValue(Instruction::BinaryOps BinaryOp, Value *RHS) { +static bool isNeutralValue(Instruction::BinaryOps BinaryOp, Value *RHS, bool IsSigned) { switch (BinaryOp) { default: llvm_unreachable("Unsupported binary op"); @@ -4994,7 +4994,8 @@ case Instruction::Sub: return match(RHS, m_Zero()); case Instruction::Mul: - return match(RHS, m_One()); + return !(RHS->getType()->isIntOrIntVectorTy(1) && IsSigned) && + match(RHS, m_One()); } } @@ -5041,7 +5042,7 @@ if (auto *LHSTy = dyn_cast(LHS->getType())) OverflowTy = VectorType::get(OverflowTy, LHSTy->getElementCount()); - if (isNeutralValue(BinaryOp, RHS)) { + if (isNeutralValue(BinaryOp, RHS, IsSigned)) { Result = LHS; Overflow = ConstantInt::getFalse(OverflowTy); return true; diff --git a/llvm/test/Transforms/InstCombine/smulo.ll b/llvm/test/Transforms/InstCombine/smulo.ll --- a/llvm/test/Transforms/InstCombine/smulo.ll +++ b/llvm/test/Transforms/InstCombine/smulo.ll @@ -160,7 +160,7 @@ define i1 @i1_ov_by_one(i1 %x) { ; CHECK-LABEL: @i1_ov_by_one( -; CHECK-NEXT: ret i1 false +; CHECK-NEXT: ret i1 [[X:%.*]] ; %m = call {i1, i1} @llvm.smul.with.overflow.i1(i1 %x, i1 1) %ov = extractvalue {i1, i1} %m, 1 @@ -169,7 +169,7 @@ define <2 x i1> @v2i1_ov_by_one(<2 x i1> %x) { ; CHECK-LABEL: @v2i1_ov_by_one( -; CHECK-NEXT: ret <2 x i1> zeroinitializer +; CHECK-NEXT: ret <2 x i1> [[X:%.*]] ; %m = call {<2 x i1>, <2 x i1>} @llvm.smul.with.overflow.v2i1(<2 x i1> %x, <2 x i1> ) %ov = extractvalue {<2 x i1>, <2 x i1>} %m, 1