CodeGen/SelectionDAG/TargetLowering.cpp

364 /// analyze the expression and return a mask of KnownOne and KnownZero bits for
370                                           APInt &KnownOne,
380   KnownZero = KnownOne = APInt(BitWidth, 0);
385       // If not at the root, Just compute the KnownZero/KnownOne bits to
387       TLO.DAG.ComputeMaskedBits(Op, KnownZero, KnownOne, Depth);
406     KnownOne = cast<ConstantSDNode>(Op)->getAPIntValue();
407     KnownZero = ~KnownOne;
428                              KnownOne, TLO, Depth+1))
430     assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
438     if ((NewMask & ~KnownZero2 & KnownOne) == (~KnownZero2 & NewMask))
453     KnownOne &= KnownOne2;
459                              KnownOne, TLO, Depth+1))
461     assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
462     if (SimplifyDemandedBits(Op.getOperand(0), ~KnownOne & NewMask,
471     if ((NewMask & ~KnownOne & KnownZero2) == (~KnownOne & NewMask))
477     if ((NewMask & ~KnownZero2 & KnownOne) == (~KnownZero2 & NewMask))
489     KnownOne |= KnownOne2;
493                              KnownOne, TLO, Depth+1))
495     assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
520     KnownZeroOut = (KnownZero & KnownZero2) | (KnownOne & KnownOne2);
522     KnownOneOut = (KnownZero & KnownOne2) | (KnownOne & KnownZero2);
529     if ((NewMask & (KnownZero|KnownOne)) == NewMask) { // all known on one side
530       if (KnownOne == KnownOne2) { // set bits are the same on both sides
532         SDValue ANDC = TLO.DAG.getConstant(~KnownOne & NewMask, VT);
559     KnownOne  = KnownOneOut;
563                              KnownOne, TLO, Depth+1))
568     assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
576     KnownOne &= KnownOne2;
581                              KnownOne, TLO, Depth+1))
586     assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
594     KnownOne &= KnownOne2;
629                                KnownZero, KnownOne, TLO, Depth+1))
679       KnownOne  <<= SA->getZExtValue();
718                                KnownZero, KnownOne, TLO, Depth+1))
720       assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
722       KnownOne  = KnownOne.lshr(ShAmt);
755                                KnownZero, KnownOne, TLO, Depth+1))
757       assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
759       KnownOne  = KnownOne.lshr(ShAmt);
781       if (KnownOne.intersects(SignBit))
783         KnownOne |= HighBits;
828                              KnownZero, KnownOne, TLO, Depth+1))
830     assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
840     if (KnownOne.intersects(InSignBit)) {    // Input sign bit known set
841       KnownOne |= NewBits;
845       KnownOne &= ~NewBits;
863                              KnownZero, KnownOne, TLO, Depth+1))
865     assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
867     KnownOne = KnownOne.zext(BitWidth);
891                              KnownOne, TLO, Depth+1))
894     KnownOne = KnownOne.zext(BitWidth);
903     if (KnownOne.intersects(InSignBit)) {
904       KnownOne |= NewBits;
907       assert((KnownOne & NewBits) == 0);
917                              KnownZero, KnownOne, TLO, Depth+1))
919     assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
921     KnownOne = KnownOne.zext(BitWidth);
931                              KnownZero, KnownOne, TLO, Depth+1))
934     KnownOne = KnownOne.trunc(BitWidth);
979     assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
989                              KnownZero, KnownOne, TLO, Depth+1))
991     assert((KnownZero & KnownOne) == 0 && "Bits known to be one AND zero?");
1042     TLO.DAG.ComputeMaskedBits(Op, KnownZero, KnownOne, Depth);
1048   if ((NewMask & (KnownZero|KnownOne)) == NewMask)
1049     return TLO.CombineTo(Op, TLO.DAG.getConstant(KnownOne, Op.getValueType()));
1056 /// KnownZero/KnownOne bitsets.
1059                                                     APInt &KnownOne,
1068   KnownZero = KnownOne = APInt(KnownOne.getBitWidth(), 0);
1112   APInt KnownZero, KnownOne;
1113   DAG.ComputeMaskedBits(Val, KnownZero, KnownOne);
1115          (KnownOne.countPopulation() == 1);