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Extract recognition of patterns such as add(add(mul(x,y),a),b) 

into a seperate function.

llvm-svn: 98162
This commit is contained in:
Richard Osborne 2010-03-10 17:10:35 +00:00
parent 9e92d3f99d
commit 5a457de4b2
1 changed files with 66 additions and 48 deletions
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114
llvm/lib/Target/XCore/XCoreISelLowering.cpp
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@ -583,6 +583,64 @@ LowerUMUL_LOHI(SDValue Op, SelectionDAG &DAG)
return DAG.getMergeValues(Ops, 2, dl);
}
/// isADDADDMUL - Return whether Op is in a form that is equivalent to
/// add(add(mul(x,y),a),b). If requireIntermediatesHaveOneUse is true then
/// each intermediate result in the calculation must also have a single use.
/// If the Op is in the correct form the constituent parts are written to Mul0,
/// Mul1, Addend0 and Addend1.
static bool
isADDADDMUL(SDValue Op, SDValue &Mul0, SDValue &Mul1, SDValue &Addend0,
SDValue &Addend1, bool requireIntermediatesHaveOneUse)
{
if (Op.getOpcode() != ISD::ADD)
return false;
SDValue N0 = Op.getOperand(0);
SDValue N1 = Op.getOperand(1);
SDValue AddOp;
SDValue OtherOp;
if (N0.getOpcode() == ISD::ADD) {
AddOp = N0;
OtherOp = N1;
} else if (N1.getOpcode() == ISD::ADD) {
AddOp = N1;
OtherOp = N0;
} else {
return false;
}
if (OtherOp.getOpcode() == ISD::MUL) {
// add(add(a,b),mul(x,y))
if (requireIntermediatesHaveOneUse &&
(!OtherOp.hasOneUse() || !AddOp.hasOneUse()))
return false;
Mul0 = OtherOp.getOperand(0);
Mul1 = OtherOp.getOperand(1);
Addend0 = AddOp.getOperand(0);
Addend1 = AddOp.getOperand(1);
return true;
}
if (AddOp.getOperand(0).getOpcode() == ISD::MUL) {
// add(add(mul(x,y),a),b)
if (requireIntermediatesHaveOneUse && !AddOp.getOperand(0).hasOneUse())
return false;
Mul0 = AddOp.getOperand(0).getOperand(0);
Mul1 = AddOp.getOperand(0).getOperand(1);
Addend0 = AddOp.getOperand(1);
Addend1 = OtherOp;
return true;
}
if (AddOp.getOperand(1).getOpcode() == ISD::MUL) {
// add(add(a,mul(x,y)),b)
if (requireIntermediatesHaveOneUse && !AddOp.getOperand(1).hasOneUse())
return false;
Mul0 = AddOp.getOperand(1).getOperand(0);
Mul1 = AddOp.getOperand(1).getOperand(1);
Addend0 = AddOp.getOperand(0);
Addend1 = OtherOp;
return true;
}
return false;
}
SDValue XCoreTargetLowering::
TryExpandADDWithMul(SDNode *N, SelectionDAG &DAG)
{
@ -1286,55 +1344,15 @@ SDValue XCoreTargetLowering::PerformDAGCombine(SDNode *N,
// Fold expressions such as add(add(mul(x,y),a),b) -> lmul(x, y, a, b).
// This is only profitable if the intermediate results are unused
// elsewhere.
SDValue N0 = N->getOperand(0);
SDValue N1 = N->getOperand(1);
SDValue AddOp;
SDValue OtherOp;
if (N0.getOpcode() == ISD::ADD) {
AddOp = N0;
OtherOp = N1;
} else if (N1.getOpcode() == ISD::ADD) {
AddOp = N1;
OtherOp = N0;
} else {
break;
SDValue Mul0, Mul1, Addend0, Addend1;
if (isADDADDMUL(SDValue(N, 0), Mul0, Mul1, Addend0, Addend1, true)) {
SDValue Zero = DAG.getConstant(0, MVT::i32);
SDValue Ignored = DAG.getNode(XCoreISD::LMUL, dl,
DAG.getVTList(MVT::i32, MVT::i32), Mul0,
Mul1, Addend0, Addend1);
SDValue Result(Ignored.getNode(), 1);
return Result;
}
SDValue Addend0, Addend1;
SDValue Mul0;
SDValue Mul1;
if (OtherOp.getOpcode() == ISD::MUL) {
// add(add(a,b),mul(x,y))
if (!OtherOp.hasOneUse() || !AddOp.hasOneUse())
break;
Mul0 = OtherOp.getOperand(0);
Mul1 = OtherOp.getOperand(1);
Addend0 = AddOp.getOperand(0);
Addend1 = AddOp.getOperand(1);
} else if (AddOp.getOperand(0).getOpcode() == ISD::MUL) {
// add(add(mul(x,y),a),b)
if (!AddOp.getOperand(0).hasOneUse())
break;
Mul0 = AddOp.getOperand(0).getOperand(0);
Mul1 = AddOp.getOperand(0).getOperand(1);
Addend0 = AddOp.getOperand(1);
Addend1 = OtherOp;
} else if (AddOp.getOperand(1).getOpcode() == ISD::MUL) {
// add(add(a,mul(x,y)),b)
if (!AddOp.getOperand(1).hasOneUse())
break;
Mul0 = AddOp.getOperand(1).getOperand(0);
Mul1 = AddOp.getOperand(1).getOperand(1);
Addend0 = AddOp.getOperand(0);
Addend1 = OtherOp;
} else {
break;
}
SDValue Zero = DAG.getConstant(0, MVT::i32);
SDValue Ignored = DAG.getNode(XCoreISD::LMUL, dl,
DAG.getVTList(MVT::i32, MVT::i32), Mul0,
Mul1, Addend0, Addend1);
SDValue Result(Ignored.getNode(), 1);
return Result;
}
break;
case ISD::STORE: {