[DAGCombiner] Remove shuffle support from simplifyShuffleMask

rL310372 enabled simplifyShuffleMask to support undef shuffle mask inputs, but its causing hangs.

Removing support until I can triage the problem

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@310699 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 7515a7a..a247f26 100644 (file)
--- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -15161,8 +15161,6 @@ static SDValue simplifyShuffleMask(ShuffleVectorSDNode *SVN, SDValue N0,
     // TODO - handle more cases as required.
     if (V.getOpcode() == ISD::BUILD_VECTOR)
       return V.getOperand(Idx).isUndef();
-    if (auto *SVN = dyn_cast<ShuffleVectorSDNode>(V))
-      return SVN->getMaskElt(Idx) < 0;
     return false;
   };
 

diff --git a/test/CodeGen/X86/oddshuffles.ll b/test/CodeGen/X86/oddshuffles.ll
index 5dba96a..0bda41a 100644 (file)
--- a/test/CodeGen/X86/oddshuffles.ll
+++ b/test/CodeGen/X86/oddshuffles.ll
@@ -258,7 +258,7 @@ define void @v7i8(<4 x i8> %a, <4 x i8> %b, <7 x i8>* %p) nounwind {
 ; SSE42-NEXT:    pextrb $0, %xmm1, 6(%rdi)
 ; SSE42-NEXT:    pshufb {{.*#+}} xmm1 = xmm1[8,9,8,9,4,5,8,9,0,1,12,13,0,1,14,15]
 ; SSE42-NEXT:    pblendw {{.*#+}} xmm1 = xmm0[0],xmm1[1],xmm0[2],xmm1[3],xmm0[4],xmm1[5,6,7]
-; SSE42-NEXT:    pshufb {{.*#+}} xmm1 = xmm1[0,2,4,6,8,10,12,u,u,u,u,u,u,u,u,u]
+; SSE42-NEXT:    pshufb {{.*#+}} xmm1 = xmm1[0,2,4,6,8,10,12,14,u,u,u,u,u,u,u,u]
 ; SSE42-NEXT:    pextrw $2, %xmm1, 4(%rdi)
 ; SSE42-NEXT:    movd %xmm1, (%rdi)
 ; SSE42-NEXT:    retq
@@ -268,7 +268,7 @@ define void @v7i8(<4 x i8> %a, <4 x i8> %b, <7 x i8>* %p) nounwind {
 ; AVX-NEXT:    vpshufd {{.*#+}} xmm0 = xmm0[0,3,1,3]
 ; AVX-NEXT:    vpshufb {{.*#+}} xmm2 = xmm1[8,9,8,9,4,5,8,9,0,1,12,13,0,1,14,15]
 ; AVX-NEXT:    vpblendw {{.*#+}} xmm0 = xmm0[0],xmm2[1],xmm0[2],xmm2[3],xmm0[4],xmm2[5,6,7]
-; AVX-NEXT:    vpshufb {{.*#+}} xmm0 = xmm0[0,2,4,6,8,10,12,u,u,u,u,u,u,u,u,u]
+; AVX-NEXT:    vpshufb {{.*#+}} xmm0 = xmm0[0,2,4,6,8,10,12,14,u,u,u,u,u,u,u,u]
 ; AVX-NEXT:    vpextrb $0, %xmm1, 6(%rdi)
 ; AVX-NEXT:    vpextrw $2, %xmm0, 4(%rdi)
 ; AVX-NEXT:    vmovd %xmm0, (%rdi)