Commit 847aabf1 authored by Sanjay Patel's avatar Sanjay Patel
Browse files

[InstCombine] remove dead code from shuffle mask canonicalization; NFC

parent 20684092

llvm/lib/Transforms/InstCombine/InstCombineVectorOps.cpp

+2 −2
Original line number Diff line number Diff line
@@ -1891,6 +1891,7 @@ Instruction *InstCombiner::visitShuffleVectorInst(ShuffleVectorInst &SVI) { 
  SmallVector<int, 16> Mask = SVI.getShuffleMask();

  Type *Int32Ty = Type::getInt32Ty(SVI.getContext());

  if (LHS == RHS || isa<UndefValue>(LHS)) {

    assert(!isa<UndefValue>(RHS) && "Shuffle with 2 undef ops not simplified?");

    // Remap any references to RHS to use LHS.

    SmallVector<Constant*, 16> Elts;

    for (unsigned i = 0; i != VWidth; ++i) {
@@ -1899,8 +1900,7 @@ Instruction *InstCombiner::visitShuffleVectorInst(ShuffleVectorInst &SVI) { 
        continue;

      }



      if ((Mask[i] >= (int)LHSWidth && isa<UndefValue>(RHS)) ||

          (Mask[i] <  (int)LHSWidth && isa<UndefValue>(LHS))) {

      if (Mask[i] < (int)LHSWidth && isa<UndefValue>(LHS)) {

        Mask[i] = -1;     // Turn into undef.

        Elts.push_back(UndefValue::get(Int32Ty));

      } else {