diff options
Diffstat (limited to 'llvm/lib/Transforms/InstCombine')
3 files changed, 30 insertions, 15 deletions
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCasts.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCasts.cpp index 9b9fe26..f939e7a 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineCasts.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineCasts.cpp @@ -1525,7 +1525,15 @@ Instruction *InstCombinerImpl::visitSExt(SExtInst &Sext) { } // Try to extend the entire expression tree to the wide destination type. - if (shouldChangeType(SrcTy, DestTy) && canEvaluateSExtd(Src, DestTy)) { + bool ShouldExtendExpression = true; + Value *TruncSrc = nullptr; + // It is not desirable to extend expression in the trunc + sext pattern when + // destination type is narrower than original (pre-trunc) type. + if (match(Src, m_Trunc(m_Value(TruncSrc)))) + if (TruncSrc->getType()->getScalarSizeInBits() > DestBitSize) + ShouldExtendExpression = false; + if (ShouldExtendExpression && shouldChangeType(SrcTy, DestTy) && + canEvaluateSExtd(Src, DestTy)) { // Okay, we can transform this! Insert the new expression now. LLVM_DEBUG( dbgs() << "ICE: EvaluateInDifferentType converting expression type" @@ -1545,13 +1553,18 @@ Instruction *InstCombinerImpl::visitSExt(SExtInst &Sext) { ShAmt); } - Value *X; - if (match(Src, m_Trunc(m_Value(X)))) { + Value *X = TruncSrc; + if (X) { // If the input has more sign bits than bits truncated, then convert // directly to final type. unsigned XBitSize = X->getType()->getScalarSizeInBits(); - if (ComputeNumSignBits(X, &Sext) > XBitSize - SrcBitSize) - return CastInst::CreateIntegerCast(X, DestTy, /* isSigned */ true); + bool HasNSW = cast<TruncInst>(Src)->hasNoSignedWrap(); + if (HasNSW || (ComputeNumSignBits(X, &Sext) > XBitSize - SrcBitSize)) { + auto *Res = CastInst::CreateIntegerCast(X, DestTy, /* isSigned */ true); + if (auto *ResTrunc = dyn_cast<TruncInst>(Res); ResTrunc && HasNSW) + ResTrunc->setHasNoSignedWrap(true); + return Res; + } // If input is a trunc from the destination type, then convert into shifts. if (Src->hasOneUse() && X->getType() == DestTy) { diff --git a/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp b/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp index 651e305..550dfc5 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp @@ -105,6 +105,8 @@ static Value *simplifyShiftSelectingPackedElement(Instruction *I, if (~KnownShrBits.Zero != ShlAmt) return nullptr; + IRBuilderBase::InsertPointGuard Guard(IC.Builder); + IC.Builder.SetInsertPoint(I); Value *ShrAmtZ = IC.Builder.CreateICmpEQ(ShrAmt, Constant::getNullValue(ShrAmt->getType()), ShrAmt->getName() + ".z"); diff --git a/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp b/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp index 9c8de45..67f837c 100644 --- a/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp +++ b/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp @@ -3358,21 +3358,21 @@ Instruction *InstCombinerImpl::visitGetElementPtrInst(GetElementPtrInst &GEP) { if (TyAllocSize == 1) { // Canonicalize (gep i8* X, (ptrtoint Y)-(ptrtoint X)) to (bitcast Y), - // but only if the result pointer is only used as if it were an integer, - // or both point to the same underlying object (otherwise provenance is - // not necessarily retained). + // but only if the result pointer is only used as if it were an integer. + // (The case where the underlying object is the same is handled by + // InstSimplify.) Value *X = GEP.getPointerOperand(); Value *Y; - if (match(GEP.getOperand(1), - m_Sub(m_PtrToInt(m_Value(Y)), m_PtrToInt(m_Specific(X)))) && + if (match(GEP.getOperand(1), m_Sub(m_PtrToIntOrAddr(m_Value(Y)), + m_PtrToIntOrAddr(m_Specific(X)))) && GEPType == Y->getType()) { - bool HasSameUnderlyingObject = - getUnderlyingObject(X) == getUnderlyingObject(Y); + bool HasNonAddressBits = + DL.getAddressSizeInBits(AS) != DL.getPointerSizeInBits(AS); bool Changed = false; GEP.replaceUsesWithIf(Y, [&](Use &U) { - bool ShouldReplace = HasSameUnderlyingObject || - isa<ICmpInst>(U.getUser()) || - isa<PtrToIntInst>(U.getUser()); + bool ShouldReplace = isa<PtrToAddrInst>(U.getUser()) || + (!HasNonAddressBits && + isa<ICmpInst, PtrToIntInst>(U.getUser())); Changed |= ShouldReplace; return ShouldReplace; }); |