diff options
Diffstat (limited to 'lib/CodeGen/SelectionDAG/DAGCombiner.cpp')
| -rw-r--r-- | lib/CodeGen/SelectionDAG/DAGCombiner.cpp | 23 |
1 files changed, 17 insertions, 6 deletions
diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp index f7c1d061c6..e494da3644 100644 --- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp +++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp @@ -3814,6 +3814,9 @@ SDValue DAGCombiner::visitFADD(SDNode *N) { // canonicalize constant to RHS if (N0CFP && !N1CFP) return DAG.getNode(ISD::FADD, VT, N1, N0); + // fold (A + 0) -> A + if (UnsafeFPMath && N1CFP && N1CFP->getValueAPF().isZero()) + return N0; // fold (A + (-B)) -> A-B if (isNegatibleForFree(N1, LegalOperations) == 2) return DAG.getNode(ISD::FSUB, VT, N0, @@ -3852,7 +3855,8 @@ SDValue DAGCombiner::visitFSUB(SDNode *N) { if (UnsafeFPMath && N0CFP && N0CFP->getValueAPF().isZero()) { if (isNegatibleForFree(N1, LegalOperations)) return GetNegatedExpression(N1, DAG, LegalOperations); - return DAG.getNode(ISD::FNEG, VT, N1); + if (!LegalOperations || TLI.isOperationLegal(ISD::FNEG, VT)) + return DAG.getNode(ISD::FNEG, VT, N1); } // fold (A-(-B)) -> A+B if (isNegatibleForFree(N1, LegalOperations)) @@ -3881,12 +3885,16 @@ SDValue DAGCombiner::visitFMUL(SDNode *N) { // canonicalize constant to RHS if (N0CFP && !N1CFP) return DAG.getNode(ISD::FMUL, VT, N1, N0); + // fold (A * 0) -> 0 + if (UnsafeFPMath && N1CFP && N1CFP->getValueAPF().isZero()) + return N1; // fold (fmul X, 2.0) -> (fadd X, X) if (N1CFP && N1CFP->isExactlyValue(+2.0)) return DAG.getNode(ISD::FADD, VT, N0, N0); // fold (fmul X, -1.0) -> (fneg X) if (N1CFP && N1CFP->isExactlyValue(-1.0)) - return DAG.getNode(ISD::FNEG, VT, N0); + if (!LegalOperations || TLI.isOperationLegal(ISD::FNEG, VT)) + return DAG.getNode(ISD::FNEG, VT, N0); // -X * -Y -> X*Y if (char LHSNeg = isNegatibleForFree(N0, LegalOperations)) { @@ -3970,10 +3978,13 @@ SDValue DAGCombiner::visitFCOPYSIGN(SDNode *N) { const APFloat& V = N1CFP->getValueAPF(); // copysign(x, c1) -> fabs(x) iff ispos(c1) // copysign(x, c1) -> fneg(fabs(x)) iff isneg(c1) - if (!V.isNegative()) - return DAG.getNode(ISD::FABS, VT, N0); - else - return DAG.getNode(ISD::FNEG, VT, DAG.getNode(ISD::FABS, VT, N0)); + if (!V.isNegative()) { + if (!LegalOperations || TLI.isOperationLegal(ISD::FABS, VT)) + return DAG.getNode(ISD::FABS, VT, N0); + } else { + if (!LegalOperations || TLI.isOperationLegal(ISD::FNEG, VT)) + return DAG.getNode(ISD::FNEG, VT, DAG.getNode(ISD::FABS, VT, N0)); + } } // copysign(fabs(x), y) -> copysign(x, y) |