diff options
Diffstat (limited to 'llvm/lib')
-rw-r--r-- | llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp | 35 |
1 files changed, 19 insertions, 16 deletions
diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp index 93d5bce9abf..70b9afabfe3 100644 --- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp +++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp @@ -18665,23 +18665,26 @@ SDValue DAGCombiner::SimplifyVBinOp(SDNode *N) { Opcode, SDLoc(LHS), LHS.getValueType(), Ops, N->getFlags())) return Fold; - // Type legalization might introduce new shuffles in the DAG. - // Fold (VBinOp (shuffle (A, Undef, Mask)), (shuffle (B, Undef, Mask))) - // -> (shuffle (VBinOp (A, B)), Undef, Mask). - if (LegalTypes && isa<ShuffleVectorSDNode>(LHS) && - isa<ShuffleVectorSDNode>(RHS) && LHS.hasOneUse() && RHS.hasOneUse() && - LHS.getOperand(1).isUndef() && - RHS.getOperand(1).isUndef()) { - ShuffleVectorSDNode *SVN0 = cast<ShuffleVectorSDNode>(LHS); - ShuffleVectorSDNode *SVN1 = cast<ShuffleVectorSDNode>(RHS); - - if (SVN0->getMask().equals(SVN1->getMask())) { - SDValue UndefVector = LHS.getOperand(1); - SDValue NewBinOp = DAG.getNode(Opcode, SDLoc(N), VT, LHS.getOperand(0), + // Move unary shuffles with identical masks after a vector binop: + // VBinOp (shuffle A, Undef, Mask), (shuffle B, Undef, Mask)) + // --> shuffle (VBinOp A, B), Undef, Mask + // This does not require type legality checks because we are creating the + // same types of operations that are in the original sequence. We do have to + // restrict ops like integer div that have immediate UB (eg, div-by-zero) + // though. This code is adapted from the identical transform in instcombine. + if (Opcode != ISD::UDIV && Opcode != ISD::SDIV && + Opcode != ISD::UREM && Opcode != ISD::SREM && + Opcode != ISD::UDIVREM && Opcode != ISD::SDIVREM) { + auto *Shuf0 = dyn_cast<ShuffleVectorSDNode>(LHS); + auto *Shuf1 = dyn_cast<ShuffleVectorSDNode>(RHS); + if (Shuf0 && Shuf1 && Shuf0->getMask().equals(Shuf1->getMask()) && + LHS.getOperand(1).isUndef() && RHS.getOperand(1).isUndef() && + (LHS.hasOneUse() || RHS.hasOneUse() || LHS == RHS)) { + SDLoc DL(N); + SDValue NewBinOp = DAG.getNode(Opcode, DL, VT, LHS.getOperand(0), RHS.getOperand(0), N->getFlags()); - AddUsersToWorklist(N); - return DAG.getVectorShuffle(VT, SDLoc(N), NewBinOp, UndefVector, - SVN0->getMask()); + SDValue UndefV = LHS.getOperand(1); + return DAG.getVectorShuffle(VT, DL, NewBinOp, UndefV, Shuf0->getMask()); } } |