}
}
-SDValue AMDGPUTargetLowering::performFNegCombine(SDNode *N,
- DAGCombinerInfo &DCI) const {
- SelectionDAG &DAG = DCI.DAG;
- SDValue N0 = N->getOperand(0);
- EVT VT = N->getValueType(0);
-
+/// \return true if it's profitable to try to push an fneg into its source
+/// instruction.
+bool AMDGPUTargetLowering::shouldFoldFNegIntoSrc(SDNode *N, SDValue N0) {
unsigned Opc = N0.getOpcode();
// If the input has multiple uses and we can either fold the negate down, or
// This may be able to fold into the source, but at a code size cost. Don't
// fold if the fold into the user is free.
if (allUsesHaveSourceMods(N, 0))
- return SDValue();
+ return false;
} else {
if (fnegFoldsIntoOp(Opc) &&
(allUsesHaveSourceMods(N) || !allUsesHaveSourceMods(N0.getNode())))
- return SDValue();
+ return false;
}
+ return true;
+}
+
+SDValue AMDGPUTargetLowering::performFNegCombine(SDNode *N,
+ DAGCombinerInfo &DCI) const {
+ SelectionDAG &DAG = DCI.DAG;
+ SDValue N0 = N->getOperand(0);
+ EVT VT = N->getValueType(0);
+
+ unsigned Opc = N0.getOpcode();
+
+ if (!shouldFoldFNegIntoSrc(N, N0))
+ return SDValue();
+
SDLoc SL(N);
switch (Opc) {
case ISD::FADD: {
return Val.getOpcode() == ISD::BITCAST ? Val.getOperand(0) : Val;
}
+ static bool shouldFoldFNegIntoSrc(SDNode *FNeg, SDValue FNegSrc);
static bool allUsesHaveSourceMods(const SDNode *N,
unsigned CostThreshold = 4);
bool isFAbsFree(EVT VT) const override;