diff options
| -rw-r--r-- | lib/Transforms/Scalar/SROA.cpp | 42 |
1 files changed, 21 insertions, 21 deletions
diff --git a/lib/Transforms/Scalar/SROA.cpp b/lib/Transforms/Scalar/SROA.cpp index 85d2798268..9b81949909 100644 --- a/lib/Transforms/Scalar/SROA.cpp +++ b/lib/Transforms/Scalar/SROA.cpp @@ -2494,14 +2494,10 @@ private: assert((IsDest && II.getRawDest() == OldPtr) || (!IsDest && II.getRawSource() == OldPtr)); - // Compute the relative offset within the transfer. - unsigned IntPtrWidth = DL.getPointerSizeInBits(); - APInt RelOffset(IntPtrWidth, NewBeginOffset - BeginOffset); - - unsigned Align = II.getAlignment(); - if (Align > 1) - Align = MinAlign(RelOffset.zextOrTrunc(64).getZExtValue(), - MinAlign(II.getAlignment(), getSliceAlign())); + unsigned MinAlignment = II.getAlignment(); + if (MinAlignment == 0) + MinAlignment = 1; // Fix the '0' alignment used by memcpy and memmove. + MinAlignment = MinAlign(MinAlignment, getSliceAlign()); // For unsplit intrinsics, we simply modify the source and destination // pointers in place. This isn't just an optimization, it is a matter of @@ -2517,8 +2513,10 @@ private: else II.setSource(AdjustedPtr); - Type *CstTy = II.getAlignmentCst()->getType(); - II.setAlignment(ConstantInt::get(CstTy, Align)); + if (II.getAlignment() > MinAlignment) { + Type *CstTy = II.getAlignmentCst()->getType(); + II.setAlignment(ConstantInt::get(CstTy, MinAlignment)); + } DEBUG(dbgs() << " to: " << II << "\n"); deleteIfTriviallyDead(OldPtr); @@ -2563,12 +2561,20 @@ private: Pass.Worklist.insert(AI); } + // Compute the relative offset for the other pointer within the transfer. + unsigned IntPtrWidth = DL.getPointerSizeInBits(); + APInt OtherOffset(IntPtrWidth, NewBeginOffset - BeginOffset); + + // Factor the offset other pointer's alignment into the requinerd minimum. + MinAlignment = + MinAlign(MinAlignment, OtherOffset.zextOrTrunc(64).getZExtValue()); + if (EmitMemCpy) { Type *OtherPtrTy = OtherPtr->getType(); // Compute the other pointer, folding as much as possible to produce // a single, simple GEP in most cases. - OtherPtr = getAdjustedPtr(IRB, DL, OtherPtr, RelOffset, OtherPtrTy, + OtherPtr = getAdjustedPtr(IRB, DL, OtherPtr, OtherOffset, OtherPtrTy, OtherPtr->getName() + "."); Value *OurPtr = getNewAllocaSlicePtr(IRB, OldPtr->getType()); @@ -2577,18 +2583,12 @@ private: CallInst *New = IRB.CreateMemCpy(IsDest ? OurPtr : OtherPtr, IsDest ? OtherPtr : OurPtr, - Size, Align, II.isVolatile()); + Size, MinAlignment, II.isVolatile()); (void)New; DEBUG(dbgs() << " to: " << *New << "\n"); return false; } - // Note that we clamp the alignment to 1 here as a 0 alignment for a memcpy - // is equivalent to 1, but that isn't true if we end up rewriting this as - // a load or store. - if (!Align) - Align = 1; - bool IsWholeAlloca = NewBeginOffset == NewAllocaBeginOffset && NewEndOffset == NewAllocaEndOffset; uint64_t Size = NewEndOffset - NewBeginOffset; @@ -2610,7 +2610,7 @@ private: OtherPtrTy = SubIntTy->getPointerTo(); } - Value *SrcPtr = getAdjustedPtr(IRB, DL, OtherPtr, RelOffset, OtherPtrTy, + Value *SrcPtr = getAdjustedPtr(IRB, DL, OtherPtr, OtherOffset, OtherPtrTy, OtherPtr->getName() + "."); Value *DstPtr = &NewAI; if (!IsDest) @@ -2628,7 +2628,7 @@ private: uint64_t Offset = NewBeginOffset - NewAllocaBeginOffset; Src = extractInteger(DL, IRB, Src, SubIntTy, Offset, "extract"); } else { - Src = IRB.CreateAlignedLoad(SrcPtr, Align, II.isVolatile(), + Src = IRB.CreateAlignedLoad(SrcPtr, MinAlignment, II.isVolatile(), "copyload"); } @@ -2646,7 +2646,7 @@ private: } StoreInst *Store = cast<StoreInst>( - IRB.CreateAlignedStore(Src, DstPtr, Align, II.isVolatile())); + IRB.CreateAlignedStore(Src, DstPtr, MinAlignment, II.isVolatile())); (void)Store; DEBUG(dbgs() << " to: " << *Store << "\n"); return !II.isVolatile(); |