diff options
Diffstat (limited to 'lib/CodeGen/SelectionDAG/DAGCombiner.cpp')
| -rw-r--r-- | lib/CodeGen/SelectionDAG/DAGCombiner.cpp | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp index 23821e6f60..a83203b663 100644 --- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp +++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp @@ -5729,6 +5729,18 @@ SDValue DAGCombiner::visitFADD(SDNode *N) { DAG.getNode(ISD::FADD, N->getDebugLoc(), VT, N0.getOperand(1), N1)); + // If allow, fold (fadd (fneg x), x) -> 0.0 + if (DAG.getTarget().Options.UnsafeFPMath && + N0.getOpcode() == ISD::FNEG && N0.getOperand(0) == N1) { + return DAG.getConstantFP(0.0, VT); + } + + // If allow, fold (fadd x, (fneg x)) -> 0.0 + if (DAG.getTarget().Options.UnsafeFPMath && + N1.getOpcode() == ISD::FNEG && N1.getOperand(0) == N0) { + return DAG.getConstantFP(0.0, VT); + } + // In unsafe math mode, we can fold chains of FADD's of the same value // into multiplications. This transform is not safe in general because // we are reducing the number of rounding steps. @@ -6038,6 +6050,12 @@ SDValue DAGCombiner::visitFMA(SDNode *N) { EVT VT = N->getValueType(0); DebugLoc dl = N->getDebugLoc(); + if (DAG.getTarget().Options.UnsafeFPMath) { + if (N0CFP && N0CFP->isZero()) + return N2; + if (N1CFP && N1CFP->isZero()) + return N2; + } if (N0CFP && N0CFP->isExactlyValue(1.0)) return DAG.getNode(ISD::FADD, N->getDebugLoc(), VT, N1, N2); if (N1CFP && N1CFP->isExactlyValue(1.0)) |