[llvm-commits] [llvm] r76325 - in /llvm/trunk: lib/Transforms/Scalar/InstructionCombining.cpp test/Transforms/InstCombine/vec-single-elt.ll

[Eli Friedman]

Author: efriedma
Date: Sat Jul 18 14:04:16 2009
New Revision: 76325

URL: http://llvm.org/viewvc/llvm-project?rev=76325&view=rev
Log:
Back out 76300; apparently the preference is to canonicalize the other 
way (bitcast -> insert/extractelement).


Removed:
    llvm/trunk/test/Transforms/InstCombine/vec-single-elt.ll
Modified:
    llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp

Modified: llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp?rev=76325&r1=76324&r2=76325&view=diff

==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp Sat Jul 18 14:04:16 2009
@@ -12374,18 +12374,13 @@
     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 @@
     // 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 @@
   // 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();

Removed: llvm/trunk/test/Transforms/InstCombine/vec-single-elt.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/vec-single-elt.ll?rev=76324&view=auto

==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/vec-single-elt.ll (original)
+++ llvm/trunk/test/Transforms/InstCombine/vec-single-elt.ll (removed)
@@ -1,12 +0,0 @@
-; RUN: llvm-as < %s | opt -instcombine | llvm-dis | not grep element
-; insert/extractelement should canonicalize to bitcast
-
-define i64 @a(<1 x i64> %x) {
-  %r = extractelement <1 x i64> %x, i32 0
-  ret i64 %r
-}
-
-define <1 x i64> @b(i64 %x) {
-  %r = insertelement <1 x i64> undef, i64 %x, i32 0
-  ret <1 x i64> %r
-}