diff options
| -rw-r--r-- | lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp | 3 | ||||
| -rw-r--r-- | test/Transforms/InstCombine/vec_demanded_elts.ll | 11 |
2 files changed, 14 insertions, 0 deletions
diff --git a/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp b/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp index 66f39be17b..81929bc623 100644 --- a/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp +++ b/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp @@ -962,6 +962,9 @@ Value *InstCombiner::SimplifyDemandedVectorElts(Value *V, APInt DemandedElts, unsigned MaskVal = Shuffle->getMaskValue(i); if (MaskVal == -1u) { UndefElts.setBit(i); + } else if (!DemandedElts[i]) { + NewUndefElts = true; + UndefElts.setBit(i); } else if (MaskVal < LHSVWidth) { if (UndefElts4[MaskVal]) { NewUndefElts = true; diff --git a/test/Transforms/InstCombine/vec_demanded_elts.ll b/test/Transforms/InstCombine/vec_demanded_elts.ll index e0188fe91a..cc63371ede 100644 --- a/test/Transforms/InstCombine/vec_demanded_elts.ll +++ b/test/Transforms/InstCombine/vec_demanded_elts.ll @@ -152,3 +152,14 @@ entry: ret <4 x i32> %0 } declare <4 x i32> @llvm.x86.sse41.pmovzxwd(<8 x i16>) nounwind readnone + +define <4 x float> @dead_shuffle_elt(<4 x float> %x, <2 x float> %y) nounwind { +entry: +; CHECK: define <4 x float> @dead_shuffle_elt +; CHECK: shufflevector <2 x float> %y, <2 x float> undef, <4 x i32> <i32 0, i32 1, i32 undef, i32 undef> + %shuffle.i = shufflevector <2 x float> %y, <2 x float> %y, <4 x i32> <i32 0, i32 1, i32 0, i32 1> + %shuffle9.i = shufflevector <4 x float> %x, <4 x float> %shuffle.i, <4 x i32> <i32 4, i32 5, i32 2, i32 3> + ret <4 x float> %shuffle9.i +} + + |