Fix a vectorshuffle instcombine bug introduced by r55995.
Patch by Nicolas Capens!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56129 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp
index 5a9d1de..f02a710 100644
--- a/lib/Transforms/Scalar/InstructionCombining.cpp
+++ b/lib/Transforms/Scalar/InstructionCombining.cpp
@@ -11311,8 +11311,11 @@
   unsigned VWidth = cast<VectorType>(SVI.getType())->getNumElements();
   uint64_t AllOnesEltMask = ~0ULL >> (64-VWidth);
   if (VWidth <= 64 &&
-      SimplifyDemandedVectorElts(&SVI, AllOnesEltMask, UndefElts))
+      SimplifyDemandedVectorElts(&SVI, AllOnesEltMask, UndefElts)) {
+    LHS = SVI.getOperand(0);
+    RHS = SVI.getOperand(1);
     MadeChange = true;
+  }
   
   // Canonicalize shuffle(x    ,x,mask) -> shuffle(x, undef,mask')
   // Canonicalize shuffle(undef,x,mask) -> shuffle(x, undef,mask').