2 files changed, 10 insertions, 12 deletions
diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 82c61faaa54..779a0b5c8bd 100644
--- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -14633,12 +14633,6 @@ SDValue DAGCombiner::visitVECTOR_SHUFFLE(SDNode *N) {
       return DAG.getVectorShuffle(VT, SDLoc(N), N0, N1, NewMask);
   }
 
-  // A shuffle of a splat is always the splat itself:
-  // shuffle (splat-shuffle), undef, M --> splat-shuffle
-  if (auto *N0Shuf = dyn_cast<ShuffleVectorSDNode>(N0))
-    if (N1.isUndef() && N0Shuf->isSplat())
-      return N0;
-
   // If it is a splat, check if the argument vector is another splat or a
   // build_vector.
   if (SVN->isSplat() && SVN->getSplatIndex() < (int)NumElts) {
diff --git a/llvm/test/CodeGen/X86/shuffle-of-splat-multiuses.ll b/llvm/test/CodeGen/X86/shuffle-of-splat-multiuses.ll
index e7011df8362..38d45ca99eb 100644
--- a/llvm/test/CodeGen/X86/shuffle-of-splat-multiuses.ll
+++ b/llvm/test/CodeGen/X86/shuffle-of-splat-multiuses.ll
@@ -5,8 +5,9 @@
 define <2 x double> @foo2(<2 x double> %v, <2 x double> *%p) nounwind {
 ; AVX2-LABEL: foo2:
 ; AVX2:       # BB#0:
-; AVX2-NEXT:    vpermilpd {{.*#+}} xmm0 = xmm0[1,1]
-; AVX2-NEXT:    vmovapd %xmm0, (%rdi)
+; AVX2-NEXT:    vpermilpd {{.*#+}} xmm1 = xmm0[1,1]
+; AVX2-NEXT:    vpermilpd {{.*#+}} xmm0 = xmm1[1,0]
+; AVX2-NEXT:    vmovapd %xmm1, (%rdi)
 ; AVX2-NEXT:    retq
   %res = shufflevector <2 x double> %v, <2 x double> undef, <2 x i32> <i32 1, i32 1>
   %res1 = shufflevector<2 x double> %res, <2 x double> undef, <2 x i32> <i32 1, i32 undef>
@@ -17,8 +18,9 @@ define <2 x double> @foo2(<2 x double> %v, <2 x double> *%p) nounwind {
 define <4 x double> @foo4(<4 x double> %v, <4 x double> *%p) nounwind {
 ; AVX2-LABEL: foo4:
 ; AVX2:       # BB#0:
-; AVX2-NEXT:    vpermpd {{.*#+}} ymm0 = ymm0[2,2,2,2]
-; AVX2-NEXT:    vmovapd %ymm0, (%rdi)
+; AVX2-NEXT:    vpermpd {{.*#+}} ymm1 = ymm0[2,2,2,2]
+; AVX2-NEXT:    vpermpd {{.*#+}} ymm0 = ymm1[2,0,2,3]
+; AVX2-NEXT:    vmovapd %ymm1, (%rdi)
 ; AVX2-NEXT:    retq
   %res = shufflevector <4 x double> %v, <4 x double> undef, <4 x i32> <i32 2, i32 2, i32 2, i32 2>
   %res1 = shufflevector<4 x double> %res, <4 x double> undef, <4 x i32> <i32 2, i32 0, i32 undef, i32 undef>
@@ -30,8 +32,10 @@ define <8 x float> @foo8(<8 x float> %v, <8 x float> *%p) nounwind {
 ; AVX2-LABEL: foo8:
 ; AVX2:       # BB#0:
 ; AVX2-NEXT:    vmovshdup {{.*#+}} ymm0 = ymm0[1,1,3,3,5,5,7,7]
-; AVX2-NEXT:    vpermpd {{.*#+}} ymm0 = ymm0[2,2,2,2]
-; AVX2-NEXT:    vmovapd %ymm0, (%rdi)
+; AVX2-NEXT:    vpermpd {{.*#+}} ymm1 = ymm0[2,2,2,2]
+; AVX2-NEXT:    vmovaps {{.*#+}} ymm0 = <2,0,u,u,5,1,3,7>
+; AVX2-NEXT:    vpermps %ymm1, %ymm0, %ymm0
+; AVX2-NEXT:    vmovapd %ymm1, (%rdi)
 ; AVX2-NEXT:    retq
   %res = shufflevector <8 x float> %v, <8 x float> undef, <8 x i32> <i32 5, i32 5, i32 5, i32 5, i32 5, i32 5, i32 5, i32 5>
   %res1 = shufflevector<8 x float> %res, <8 x float> undef, <8 x i32> <i32 2, i32 0, i32 undef, i32 undef, i32 5, i32 1, i32 3, i32 7>