diff options
Diffstat (limited to 'llvm/lib/IR/Instructions.cpp')
| -rw-r--r-- | llvm/lib/IR/Instructions.cpp | 16 |
1 files changed, 10 insertions, 6 deletions
diff --git a/llvm/lib/IR/Instructions.cpp b/llvm/lib/IR/Instructions.cpp index 88e7c44..9060a89 100644 --- a/llvm/lib/IR/Instructions.cpp +++ b/llvm/lib/IR/Instructions.cpp @@ -2965,8 +2965,7 @@ unsigned CastInst::isEliminableCastPair(Instruction::CastOps firstOp, // zext, sext -> zext, because sext can't sign extend after zext return Instruction::ZExt; case 11: { - // inttoptr, ptrtoint/ptrtoaddr -> bitcast if SrcSize<=PtrSize/AddrSize - // and SrcSize==DstSize + // inttoptr, ptrtoint/ptrtoaddr -> integer cast if (!DL) return 0; unsigned MidSize = secondOp == Instruction::PtrToAddr @@ -2974,10 +2973,15 @@ unsigned CastInst::isEliminableCastPair(Instruction::CastOps firstOp, : DL->getPointerTypeSizeInBits(MidTy); unsigned SrcSize = SrcTy->getScalarSizeInBits(); unsigned DstSize = DstTy->getScalarSizeInBits(); - // TODO: Could also produce zext or trunc here. - if (SrcSize <= MidSize && SrcSize == DstSize) - return Instruction::BitCast; - return 0; + // If the middle size is smaller than both source and destination, + // an additional masking operation would be required. + if (MidSize < SrcSize && MidSize < DstSize) + return 0; + if (DstSize < SrcSize) + return Instruction::Trunc; + if (DstSize > SrcSize) + return Instruction::ZExt; + return Instruction::BitCast; } case 12: // addrspacecast, addrspacecast -> bitcast, if SrcAS == DstAS |