[llvm-commits] [llvm] r76300 - in /llvm/trunk: lib/Transforms/Scalar/InstructionCombining.cpp test/Transforms/InstCombine/vec-single-elt.ll
Eli Friedman
eli.friedman at gmail.com
Sat Jul 18 02:07:51 PDT 2009
Author: efriedma
Date: Sat Jul 18 04:07:47 2009
New Revision: 76300
URL: http://llvm.org/viewvc/llvm-project?rev=76300&view=rev
Log:
Canonicalize insert/extractelement from single-element vectors into
bitcasts.
It would also be possible to canonicalize the other way; does anyone
have a preference?
Added:
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=76300&r1=76299&r2=76300&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp Sat Jul 18 04:07:47 2009
@@ -12366,13 +12366,18 @@
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.
@@ -12382,7 +12387,7 @@
// 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() && VectorWidth != 1) {
+ if (EI.getOperand(0)->hasOneUse()) {
APInt UndefElts(VectorWidth, 0);
APInt DemandedMask(VectorWidth, 1 << IndexVal);
if (Value *V = SimplifyDemandedVectorElts(EI.getOperand(0),
@@ -12619,13 +12624,18 @@
// 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();
Added: 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=76300&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/vec-single-elt.ll (added)
+++ llvm/trunk/test/Transforms/InstCombine/vec-single-elt.ll Sat Jul 18 04:07:47 2009
@@ -0,0 +1,12 @@
+; 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
+}
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