+/// ExpandShiftWithKnownAmountBit - Try to determine whether we can simplify
+/// this shift based on knowledge of the high bit of the shift amount. If we
+/// can tell this, we know that it is >= 32 or < 32, without knowing the actual
+/// shift amount.
+bool DAGTypeLegalizer::
+ExpandShiftWithKnownAmountBit(SDNode *N, SDValue &Lo, SDValue &Hi) {
+ SDValue Amt = N->getOperand(1);
+ MVT NVT = TLI.getTypeToTransformTo(N->getValueType(0));
+ MVT ShTy = Amt.getValueType();
+ unsigned ShBits = ShTy.getSizeInBits();
+ unsigned NVTBits = NVT.getSizeInBits();
+ assert(isPowerOf2_32(NVTBits) &&
+ "Expanded integer type size not a power of two!");
+
+ APInt HighBitMask = APInt::getHighBitsSet(ShBits, ShBits - Log2_32(NVTBits));
+ APInt KnownZero, KnownOne;
+ DAG.ComputeMaskedBits(N->getOperand(1), HighBitMask, KnownZero, KnownOne);
+
+ // If we don't know anything about the high bits, exit.
+ if (((KnownZero|KnownOne) & HighBitMask) == 0)
+ return false;
+
+ // Get the incoming operand to be shifted.
+ SDValue InL, InH;
+ GetExpandedInteger(N->getOperand(0), InL, InH);
+
+ // If we know that any of the high bits of the shift amount are one, then we
+ // can do this as a couple of simple shifts.
+ if (KnownOne.intersects(HighBitMask)) {
+ // Mask out the high bit, which we know is set.
+ Amt = DAG.getNode(ISD::AND, ShTy, Amt,
+ DAG.getConstant(~HighBitMask, ShTy));
+
+ switch (N->getOpcode()) {
+ default: assert(0 && "Unknown shift");
+ case ISD::SHL:
+ Lo = DAG.getConstant(0, NVT); // Low part is zero.
+ Hi = DAG.getNode(ISD::SHL, NVT, InL, Amt); // High part from Lo part.
+ return true;
+ case ISD::SRL:
+ Hi = DAG.getConstant(0, NVT); // Hi part is zero.
+ Lo = DAG.getNode(ISD::SRL, NVT, InH, Amt); // Lo part from Hi part.
+ return true;
+ case ISD::SRA:
+ Hi = DAG.getNode(ISD::SRA, NVT, InH, // Sign extend high part.
+ DAG.getConstant(NVTBits-1, ShTy));
+ Lo = DAG.getNode(ISD::SRA, NVT, InH, Amt); // Lo part from Hi part.
+ return true;
+ }
+ }
+
+#if 0
+ // FIXME: This code is broken for shifts with a zero amount!
+ // If we know that all of the high bits of the shift amount are zero, then we
+ // can do this as a couple of simple shifts.
+ if ((KnownZero & HighBitMask) == HighBitMask) {
+ // Compute 32-amt.
+ SDValue Amt2 = DAG.getNode(ISD::SUB, ShTy,
+ DAG.getConstant(NVTBits, ShTy),
+ Amt);
+ unsigned Op1, Op2;
+ switch (N->getOpcode()) {
+ default: assert(0 && "Unknown shift");
+ case ISD::SHL: Op1 = ISD::SHL; Op2 = ISD::SRL; break;
+ case ISD::SRL:
+ case ISD::SRA: Op1 = ISD::SRL; Op2 = ISD::SHL; break;
+ }
+
+ Lo = DAG.getNode(N->getOpcode(), NVT, InL, Amt);
+ Hi = DAG.getNode(ISD::OR, NVT,
+ DAG.getNode(Op1, NVT, InH, Amt),
+ DAG.getNode(Op2, NVT, InL, Amt2));
+ return true;
+ }
+#endif
+
+ return false;
+}
+
+void DAGTypeLegalizer::ExpandIntRes_ADDSUB(SDNode *N,
+ SDValue &Lo, SDValue &Hi) {
+ // Expand the subcomponents.
+ SDValue LHSL, LHSH, RHSL, RHSH;
+ GetExpandedInteger(N->getOperand(0), LHSL, LHSH);
+ GetExpandedInteger(N->getOperand(1), RHSL, RHSH);
+
+ MVT NVT = LHSL.getValueType();
+ SDValue LoOps[2] = { LHSL, RHSL };
+ SDValue HiOps[3] = { LHSH, RHSH };
+
+ // Do not generate ADDC/ADDE or SUBC/SUBE if the target does not support
+ // them. TODO: Teach operation legalization how to expand unsupported
+ // ADDC/ADDE/SUBC/SUBE. The problem is that these operations generate
+ // a carry of type MVT::Flag, but there doesn't seem to be any way to
+ // generate a value of this type in the expanded code sequence.
+ bool hasCarry =
+ TLI.isOperationLegal(N->getOpcode() == ISD::ADD ? ISD::ADDC : ISD::SUBC,
+ TLI.getTypeToExpandTo(NVT));
+
+ if (hasCarry) {
+ SDVTList VTList = DAG.getVTList(NVT, MVT::Flag);
+ if (N->getOpcode() == ISD::ADD) {
+ Lo = DAG.getNode(ISD::ADDC, VTList, LoOps, 2);
+ HiOps[2] = Lo.getValue(1);
+ Hi = DAG.getNode(ISD::ADDE, VTList, HiOps, 3);
+ } else {
+ Lo = DAG.getNode(ISD::SUBC, VTList, LoOps, 2);
+ HiOps[2] = Lo.getValue(1);
+ Hi = DAG.getNode(ISD::SUBE, VTList, HiOps, 3);
+ }
+ } else {
+ if (N->getOpcode() == ISD::ADD) {
+ Lo = DAG.getNode(ISD::ADD, NVT, LoOps, 2);
+ Hi = DAG.getNode(ISD::ADD, NVT, HiOps, 2);
+ SDValue Cmp1 = DAG.getSetCC(TLI.getSetCCResultType(NVT), Lo, LoOps[0],
+ ISD::SETULT);
+ SDValue Carry1 = DAG.getNode(ISD::SELECT, NVT, Cmp1,
+ DAG.getConstant(1, NVT),
+ DAG.getConstant(0, NVT));
+ SDValue Cmp2 = DAG.getSetCC(TLI.getSetCCResultType(NVT), Lo, LoOps[1],
+ ISD::SETULT);
+ SDValue Carry2 = DAG.getNode(ISD::SELECT, NVT, Cmp2,
+ DAG.getConstant(1, NVT), Carry1);
+ Hi = DAG.getNode(ISD::ADD, NVT, Hi, Carry2);
+ } else {
+ Lo = DAG.getNode(ISD::SUB, NVT, LoOps, 2);
+ Hi = DAG.getNode(ISD::SUB, NVT, HiOps, 2);
+ SDValue Cmp =
+ DAG.getSetCC(TLI.getSetCCResultType(LoOps[0].getValueType()),
+ LoOps[0], LoOps[1], ISD::SETULT);
+ SDValue Borrow = DAG.getNode(ISD::SELECT, NVT, Cmp,
+ DAG.getConstant(1, NVT),
+ DAG.getConstant(0, NVT));
+ Hi = DAG.getNode(ISD::SUB, NVT, Hi, Borrow);
+ }
+ }
+}
+
+void DAGTypeLegalizer::ExpandIntRes_ADDSUBC(SDNode *N,
+ SDValue &Lo, SDValue &Hi) {
+ // Expand the subcomponents.
+ SDValue LHSL, LHSH, RHSL, RHSH;
+ GetExpandedInteger(N->getOperand(0), LHSL, LHSH);
+ GetExpandedInteger(N->getOperand(1), RHSL, RHSH);
+ SDVTList VTList = DAG.getVTList(LHSL.getValueType(), MVT::Flag);
+ SDValue LoOps[2] = { LHSL, RHSL };
+ SDValue HiOps[3] = { LHSH, RHSH };
+
+ if (N->getOpcode() == ISD::ADDC) {
+ Lo = DAG.getNode(ISD::ADDC, VTList, LoOps, 2);
+ HiOps[2] = Lo.getValue(1);
+ Hi = DAG.getNode(ISD::ADDE, VTList, HiOps, 3);
+ } else {
+ Lo = DAG.getNode(ISD::SUBC, VTList, LoOps, 2);
+ HiOps[2] = Lo.getValue(1);
+ Hi = DAG.getNode(ISD::SUBE, VTList, HiOps, 3);
+ }
+
+ // Legalized the flag result - switch anything that used the old flag to
+ // use the new one.
+ ReplaceValueWith(SDValue(N, 1), Hi.getValue(1));
+}
+
+void DAGTypeLegalizer::ExpandIntRes_ADDSUBE(SDNode *N,
+ SDValue &Lo, SDValue &Hi) {
+ // Expand the subcomponents.
+ SDValue LHSL, LHSH, RHSL, RHSH;
+ GetExpandedInteger(N->getOperand(0), LHSL, LHSH);
+ GetExpandedInteger(N->getOperand(1), RHSL, RHSH);
+ SDVTList VTList = DAG.getVTList(LHSL.getValueType(), MVT::Flag);
+ SDValue LoOps[3] = { LHSL, RHSL, N->getOperand(2) };
+ SDValue HiOps[3] = { LHSH, RHSH };
+
+ Lo = DAG.getNode(N->getOpcode(), VTList, LoOps, 3);
+ HiOps[2] = Lo.getValue(1);
+ Hi = DAG.getNode(N->getOpcode(), VTList, HiOps, 3);
+
+ // Legalized the flag result - switch anything that used the old flag to
+ // use the new one.
+ ReplaceValueWith(SDValue(N, 1), Hi.getValue(1));
+}
+
+void DAGTypeLegalizer::ExpandIntRes_ANY_EXTEND(SDNode *N,
+ SDValue &Lo, SDValue &Hi) {