Handle vector move / load which zero the destination register top bits (i.e. movd, movq, movss (addr), movsd (addr)) with X86 specific dag combine.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50838 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/X86ISelDAGToDAG.cpp b/lib/Target/X86/X86ISelDAGToDAG.cpp
index 8286cd0..1e9a0da 100644
--- a/lib/Target/X86/X86ISelDAGToDAG.cpp
+++ b/lib/Target/X86/X86ISelDAGToDAG.cpp
@@ -975,38 +975,19 @@
// Also handle the case where we explicitly require zeros in the top
// elements. This is a vector shuffle from the zero vector.
- if (N.getOpcode() == ISD::VECTOR_SHUFFLE && N.Val->hasOneUse() &&
+ if (N.getOpcode() == X86ISD::ZEXT_VMOVL && N.Val->hasOneUse() &&
// Check to see if the top elements are all zeros (or bitcast of zeros).
- ISD::isBuildVectorAllZeros(N.getOperand(0).Val) &&
- N.getOperand(1).getOpcode() == ISD::SCALAR_TO_VECTOR &&
- N.getOperand(1).Val->hasOneUse() &&
- ISD::isNON_EXTLoad(N.getOperand(1).getOperand(0).Val) &&
- N.getOperand(1).getOperand(0).hasOneUse()) {
- // Check to see if the shuffle mask is 4/L/L/L or 2/L, where L is something
- // from the LHS.
- unsigned VecWidth=MVT::getVectorNumElements(N.getOperand(0).getValueType());
- SDOperand ShufMask = N.getOperand(2);
- assert(ShufMask.getOpcode() == ISD::BUILD_VECTOR && "Invalid shuf mask!");
- if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(ShufMask.getOperand(0))) {
- if (C->getValue() == VecWidth) {
- for (unsigned i = 1; i != VecWidth; ++i) {
- if (ShufMask.getOperand(i).getOpcode() == ISD::UNDEF) {
- // ok.
- } else {
- ConstantSDNode *C = cast<ConstantSDNode>(ShufMask.getOperand(i));
- if (C->getValue() >= VecWidth) return false;
- }
- }
- }
-
- // Okay, this is a zero extending load. Fold it.
- LoadSDNode *LD = cast<LoadSDNode>(N.getOperand(1).getOperand(0));
- if (!SelectAddr(Op, LD->getBasePtr(), Base, Scale, Index, Disp))
- return false;
- OutChain = LD->getChain();
- InChain = SDOperand(LD, 1);
- return true;
- }
+ N.getOperand(0).getOpcode() == ISD::SCALAR_TO_VECTOR &&
+ N.getOperand(0).Val->hasOneUse() &&
+ ISD::isNON_EXTLoad(N.getOperand(0).getOperand(0).Val) &&
+ N.getOperand(0).getOperand(0).hasOneUse()) {
+ // Okay, this is a zero extending load. Fold it.
+ LoadSDNode *LD = cast<LoadSDNode>(N.getOperand(0).getOperand(0));
+ if (!SelectAddr(Op, LD->getBasePtr(), Base, Scale, Index, Disp))
+ return false;
+ OutChain = LD->getChain();
+ InChain = SDOperand(LD, 1);
+ return true;
}
return false;
}