Cross Reference: /external/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp

Lines Matching defs:Neg
311     SDNode *MatchRotatePosNeg(SDValue Shifted, SDValue Pos, SDValue Neg,
3460 // Return true if we can prove that, whenever Neg and Pos are both in the
3461 // range [0, OpSize), Neg == (Pos == 0 ? 0 : OpSize - Pos).  This means that
3464 //     (or (shift1 X, Neg), (shift2 X, Pos))
3467 // in direction shift1 by Neg.  The range [0, OpSize) means that we only need
3469 static bool matchRotateSub(SDValue Pos, SDValue Neg, unsigned OpSize) {
3473   //  (b) Neg == Neg & (OpSize - 1) whenever Neg is in [0, OpSize).
3475   // So if OpSize is a power of 2 and Neg is (and Neg', OpSize-1), we check
3478   //     Neg & (OpSize - 1) == (OpSize - Pos) & (OpSize - 1)    [A]
3480   // for all Neg and Pos.  Since Neg & (OpSize - 1) == Neg' & (OpSize - 1)
3481   // we can just replace Neg with Neg' for the rest of the function.
3485   //     Neg == OpSize - Pos                                    [B]
3487   // for all Neg and Pos.  Note that the (or ...) then invokes undefined
3488   // behavior if Pos == 0 (and consequently Neg == OpSize).
3492   // where Neg and Pos are never in range at the same time.  E.g. for
3493   // OpSize == 32, using [A] would allow a Neg of the form (sub 64, Pos)
3502   if (Neg.getOpcode() == ISD::AND &&
3504       Neg.getOperand(1).getOpcode() == ISD::Constant &&
3505       cast<ConstantSDNode>(Neg.getOperand(1))->getAPIntValue() == OpSize - 1) {
3506     Neg = Neg.getOperand(0);
3510   // Check whether Neg has the form (sub NegC, NegOp1) for some NegC and NegOp1.
3511   if (Neg.getOpcode() != ISD::SUB)
3513   ConstantSDNode *NegC = dyn_cast<ConstantSDNode>(Neg.getOperand(0));
3516   SDValue NegOp1 = Neg.getOperand(1);
3563 // shifts of Shifted.  If Neg == <operand size> - Pos then the OR reduces
3564 // to both (PosOpcode Shifted, Pos) and (NegOpcode Shifted, Neg), with the
3566 // Neg with outer conversions stripped away.
3568                                        SDValue Neg, SDValue InnerPos,
3582                        HasPos ? Pos : Neg).getNode();