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[X86][SSE] Move combineTo call out of combineX86ShufflesConstants. NFCI. 

Move towards making it possible to use the shuffle combines for cases where we don't want to call DCI.CombineTo() with the result.

llvm-svn: 312886
This commit is contained in:
Simon Pilgrim 2017-09-10 18:10:49 +00:00
parent 5876189ff1
commit ff347d3ea4
1 changed files with 13 additions and 11 deletions
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24
llvm/lib/Target/X86/X86ISelLowering.cpp
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@ -28087,11 +28087,12 @@ static SDValue combineX86ShuffleChain(ArrayRef<SDValue> Inputs, SDValue Root,
// Attempt to constant fold all of the constant source ops.
// Returns true if the entire shuffle is folded to a constant.
// TODO: Extend this to merge multiple constant Ops and update the mask.
static bool combineX86ShufflesConstants(const SmallVectorImpl<SDValue> &Ops,
ArrayRef<int> Mask, SDValue Root,
bool HasVariableMask, SelectionDAG &DAG,
TargetLowering::DAGCombinerInfo &DCI,
const X86Subtarget &Subtarget) {
static SDValue combineX86ShufflesConstants(const SmallVectorImpl<SDValue> &Ops,
ArrayRef<int> Mask, SDValue Root,
bool HasVariableMask,
SelectionDAG &DAG,
TargetLowering::DAGCombinerInfo &DCI,
const X86Subtarget &Subtarget) {
MVT VT = Root.getSimpleValueType();
unsigned SizeInBits = VT.getSizeInBits();
@ -28108,14 +28109,14 @@ static bool combineX86ShufflesConstants(const SmallVectorImpl<SDValue> &Ops,
OneUseConstantOp |= SrcOp.hasOneUse();
if (!getTargetConstantBitsFromNode(SrcOp, MaskSizeInBits, UndefEltsOps[i],
RawBitsOps[i]))
return false;
return SDValue();
}
// Only fold if at least one of the constants is only used once or
// the combined shuffle has included a variable mask shuffle, this
// is to avoid constant pool bloat.
if (!OneUseConstantOp && !HasVariableMask)
return false;
return SDValue();
// Shuffle the constant bits according to the mask.
APInt UndefElts(NumMaskElts, 0);
@ -28167,8 +28168,7 @@ static bool combineX86ShufflesConstants(const SmallVectorImpl<SDValue> &Ops,
SDLoc DL(Root);
SDValue CstOp = getConstVector(ConstantBitData, UndefElts, MaskVT, DAG, DL);
DCI.AddToWorklist(CstOp.getNode());
DCI.CombineTo(Root.getNode(), DAG.getBitcast(VT, CstOp));
return true;
return DAG.getBitcast(VT, CstOp);
}
/// \brief Fully generic combining of x86 shuffle instructions.
@ -28375,9 +28375,11 @@ static bool combineX86ShufflesRecursively(ArrayRef<SDValue> SrcOps,
return true;
// Attempt to constant fold all of the constant source ops.
if (combineX86ShufflesConstants(Ops, Mask, Root, HasVariableMask, DAG, DCI,
Subtarget))
if (SDValue Cst = combineX86ShufflesConstants(
Ops, Mask, Root, HasVariableMask, DAG, DCI, Subtarget)) {
DCI.CombineTo(Root.getNode(), Cst);
return true;
}
// We can only combine unary and binary shuffle mask cases.
if (Ops.size() > 2)