[llvm-commits] [llvm] r149221 - /llvm/trunk/lib/VMCore/ConstantFold.cpp

[Chris Lattner]

Author: lattner
Date: Sun Jan 29 23:34:13 2012
New Revision: 149221

URL: http://llvm.org/viewvc/llvm-project?rev=149221&view=rev
Log:
Fix ConstantFoldShuffleVectorInstruction to properly handle the case
when the result type has a different # elements than the input vectors.

Modified:
    llvm/trunk/lib/VMCore/ConstantFold.cpp

Modified: llvm/trunk/lib/VMCore/ConstantFold.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/VMCore/ConstantFold.cpp?rev=149221&r1=149220&r2=149221&view=diff
==============================================================================
--- llvm/trunk/lib/VMCore/ConstantFold.cpp (original)
+++ llvm/trunk/lib/VMCore/ConstantFold.cpp Sun Jan 29 23:34:13 2012
@@ -794,15 +794,17 @@
 Constant *llvm::ConstantFoldShuffleVectorInstruction(Constant *V1,
                                                      Constant *V2,
                                                      Constant *Mask) {
+  unsigned MaskNumElts = Mask->getType()->getVectorNumElements();
+  Type *EltTy = V1->getType()->getVectorElementType();
+
   // Undefined shuffle mask -> undefined value.
-  if (isa<UndefValue>(Mask)) return UndefValue::get(V1->getType());
+  if (isa<UndefValue>(Mask))
+    return UndefValue::get(VectorType::get(EltTy, MaskNumElts));
 
   // Don't break the bitcode reader hack.
   if (isa<ConstantExpr>(Mask)) return 0;
   
-  unsigned MaskNumElts = Mask->getType()->getVectorNumElements();
   unsigned SrcNumElts = V1->getType()->getVectorNumElements();
-  Type *EltTy = V1->getType()->getVectorElementType();
 
   // Loop over the shuffle mask, evaluating each element.
   SmallVector<Constant*, 32> Result;