Back out 76300; apparently the preference is to canonicalize the other

way (bitcast -> insert/extractelement).



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@76325 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 6 insertions, 16 deletions

diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp
index e9e5294407..21b51e4cda 100644
--- a/lib/Transforms/Scalar/InstructionCombining.cpp
+++ b/lib/Transforms/Scalar/InstructionCombining.cpp
@@ -12374,18 +12374,13 @@ Instruction *InstCombiner::visitExtractElementInst(ExtractElementInst &EI) {
     if (op0)
       return ReplaceInstUsesWith(EI, op0);
   }
-
-  unsigned VectorWidth = 
-     cast<VectorType>(EI.getOperand(0)->getType())->getNumElements();
-
-  // Canonicalize extractelement from a vector of width 1 to a bitcast
-  if (VectorWidth == 1)
-    return new BitCastInst(EI.getOperand(0), EI.getType());
-
+  
   // If extracting a specified index from the vector, see if we can recursively
   // find a previously computed scalar that was inserted into the vector.
   if (ConstantInt *IdxC = dyn_cast<ConstantInt>(EI.getOperand(1))) {
     unsigned IndexVal = IdxC->getZExtValue();
+    unsigned VectorWidth = 
+      cast<VectorType>(EI.getOperand(0)->getType())->getNumElements();
       
     // If this is extracting an invalid index, turn this into undef, to avoid
     // crashing the code below.
@@ -12395,7 +12390,7 @@ Instruction *InstCombiner::visitExtractElementInst(ExtractElementInst &EI) {
     // This instruction only demands the single element from the input vector.
     // If the input vector has a single use, simplify it based on this use
     // property.
-    if (EI.getOperand(0)->hasOneUse()) {
+    if (EI.getOperand(0)->hasOneUse() && VectorWidth != 1) {
       APInt UndefElts(VectorWidth, 0);
       APInt DemandedMask(VectorWidth, 1 << IndexVal);
       if (Value *V = SimplifyDemandedVectorElts(EI.getOperand(0),
@@ -12632,18 +12627,13 @@ Instruction *InstCombiner::visitInsertElementInst(InsertElementInst &IE) {
   // Inserting an undef or into an undefined place, remove this.
   if (isa<UndefValue>(ScalarOp) || isa<UndefValue>(IdxOp))
     ReplaceInstUsesWith(IE, VecOp);
-
-  unsigned NumVectorElts = IE.getType()->getNumElements();
-
-  // Canonicalize insertelement into vector of width 1 to a bitcast
-  if (NumVectorElts == 1)
-    return new BitCastInst(IE.getOperand(1), IE.getType());
-
+  
   // If the inserted element was extracted from some other vector, and if the 
   // indexes are constant, try to turn this into a shufflevector operation.
   if (ExtractElementInst *EI = dyn_cast<ExtractElementInst>(ScalarOp)) {
     if (isa<ConstantInt>(EI->getOperand(1)) && isa<ConstantInt>(IdxOp) &&
         EI->getOperand(0)->getType() == IE.getType()) {
+      unsigned NumVectorElts = IE.getType()->getNumElements();
       unsigned ExtractedIdx =
         cast<ConstantInt>(EI->getOperand(1))->getZExtValue();
       unsigned InsertedIdx = cast<ConstantInt>(IdxOp)->getZExtValue();