Commit 3b99dc62 authored by Nadav Rotem's avatar Nadav Rotem
Browse files

Use the isTruncFree and isZExtFree API to figure out of these operations are free. Thanks Andy! 

llvm-svn: 167685
parent 12930749

llvm/lib/Target/TargetTransformImpl.cpp

+10 −2
Original line number Diff line number Diff line
@@ -214,8 +214,16 @@ unsigned VectorTargetTransformImpl::getCastInstrCost(unsigned Opcode, Type *Dst, 
  // Handle scalar conversions.

  if (!Src->isVectorTy() && !Dst->isVectorTy()) {



    // Scalar bitcasts and truncs are usually free.

    if (Opcode == Instruction::BitCast || Opcode == Instruction::Trunc)

    // Scalar bitcasts are usually free.

    if (Opcode == Instruction::BitCast)

      return 0;



    if (Opcode == Instruction::Trunc &&

        TLI->isTruncateFree(SrcLT.second, DstLT.second))

      return 0;



    if (Opcode == Instruction::ZExt &&

        TLI->isZExtFree(SrcLT.second, DstLT.second))

      return 0;



    // Just check the op cost. If the operation is legal then assume it costs 1.