diff options
Diffstat (limited to 'llvm/lib')
| -rw-r--r-- | llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp | 23 |
1 files changed, 14 insertions, 9 deletions
diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp index 4f898bc9d7a..c1ff817fc35 100644 --- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp +++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp @@ -7321,22 +7321,27 @@ SDValue DAGCombiner::visitFNEG(SDNode *N) { &DAG.getTarget().Options)) return GetNegatedExpression(N0, DAG, LegalOperations); - // Transform fneg(bitconvert(x)) -> bitconvert(x^sign) to avoid loading + // Transform fneg(bitconvert(x)) -> bitconvert(x ^ sign) to avoid loading // constant pool values. - // TODO: We can also optimize for vectors here, but we need to make sure - // that the sign mask is created properly for each vector element. if (!TLI.isFNegFree(VT) && N0.getOpcode() == ISD::BITCAST && - !VT.isVector() && - N0.getNode()->hasOneUse() && - N0.getOperand(0).getValueType().isInteger()) { + N0.getNode()->hasOneUse()) { SDValue Int = N0.getOperand(0); EVT IntVT = Int.getValueType(); if (IntVT.isInteger() && !IntVT.isVector()) { + APInt SignMask; + if (N0.getValueType().isVector()) { + // For a vector, get a mask such as 0x80... per scalar element + // and splat it. + SignMask = APInt::getSignBit(N0.getValueType().getScalarSizeInBits()); + SignMask = APInt::getSplat(IntVT.getSizeInBits(), SignMask); + } else { + // For a scalar, just generate 0x80... + SignMask = APInt::getSignBit(IntVT.getSizeInBits()); + } Int = DAG.getNode(ISD::XOR, SDLoc(N0), IntVT, Int, - DAG.getConstant(APInt::getSignBit(IntVT.getSizeInBits()), IntVT)); + DAG.getConstant(SignMask, IntVT)); AddToWorklist(Int.getNode()); - return DAG.getNode(ISD::BITCAST, SDLoc(N), - VT, Int); + return DAG.getNode(ISD::BITCAST, SDLoc(N), VT, Int); } } |
