[llvm] r225517 - Assumption that "VectorizedValue" will always be an Instruction is not correct.

[Suyog Sarda]

Author: suyog
Date: Fri Jan  9 04:23:48 2015
New Revision: 225517

URL: http://llvm.org/viewvc/llvm-project?rev=225517&view=rev
Log:
Assumption that "VectorizedValue" will always be an Instruction is not correct.
It can be a constant or a vector argument.

ex :

define i32 @hadd(<4 x i32> %a) #0 {
entry:
  %vecext = extractelement <4 x i32> %a, i32 0
  %vecext1 = extractelement <4 x i32> %a, i32 1
  %add = add i32 %vecext, %vecext1
  %vecext2 = extractelement <4 x i32> %a, i32 2
  %add3 = add i32 %add, %vecext2
  %vecext4 = extractelement <4 x i32> %a, i32 3
  %add5 = add i32 %add3, %vecext4
  ret i32 %add5
}


Modified:
    llvm/trunk/lib/Transforms/Vectorize/SLPVectorizer.cpp

Modified: llvm/trunk/lib/Transforms/Vectorize/SLPVectorizer.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Vectorize/SLPVectorizer.cpp?rev=225517&r1=225516&r2=225517&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Vectorize/SLPVectorizer.cpp (original)
+++ llvm/trunk/lib/Transforms/Vectorize/SLPVectorizer.cpp Fri Jan  9 04:23:48 2015
@@ -3502,11 +3502,10 @@ private:
   /// \brief Emit a horizontal reduction of the vectorized value.
   Value *emitReduction(Value *VectorizedValue, IRBuilder<> &Builder) {
     assert(VectorizedValue && "Need to have a vectorized tree node");
-    Instruction *ValToReduce = dyn_cast<Instruction>(VectorizedValue);
     assert(isPowerOf2_32(ReduxWidth) &&
            "We only handle power-of-two reductions for now");
 
-    Value *TmpVec = ValToReduce;
+    Value *TmpVec = VectorizedValue;
     for (unsigned i = ReduxWidth / 2; i != 0; i >>= 1) {
       if (IsPairwiseReduction) {
         Value *LeftMask =