diff options
Diffstat (limited to 'lib/Target/ARM/ARMISelLowering.cpp')
| -rw-r--r-- | lib/Target/ARM/ARMISelLowering.cpp | 66 |
1 files changed, 66 insertions, 0 deletions
diff --git a/lib/Target/ARM/ARMISelLowering.cpp b/lib/Target/ARM/ARMISelLowering.cpp index 444e30e..34b662a 100644 --- a/lib/Target/ARM/ARMISelLowering.cpp +++ b/lib/Target/ARM/ARMISelLowering.cpp @@ -530,6 +530,9 @@ ARMTargetLowering::ARMTargetLowering(TargetMachine &TM) setTargetDAGCombine(ISD::SUB); setTargetDAGCombine(ISD::MUL); + if (Subtarget->hasV6T2Ops()) + setTargetDAGCombine(ISD::OR); + setStackPointerRegisterToSaveRestore(ARM::SP); if (UseSoftFloat || Subtarget->isThumb1Only() || !Subtarget->hasVFP2()) @@ -4232,6 +4235,53 @@ static SDValue PerformMULCombine(SDNode *N, return SDValue(); } +/// PerformORCombine - Target-specific dag combine xforms for ISD::OR +static SDValue PerformORCombine(SDNode *N, + TargetLowering::DAGCombinerInfo &DCI, + const ARMSubtarget *Subtarget) { + // BFI is only available on V6T2+ + if (Subtarget->isThumb1Only() || !Subtarget->hasV6T2Ops()) + return SDValue(); + + SelectionDAG &DAG = DCI.DAG; + SDValue N0 = N->getOperand(0), N1 = N->getOperand(1); + // or (and A, mask), val => ARMbfi A, val, mask + // iff (val & mask) == val + if (N0->getOpcode() != ISD::AND) + return SDValue(); + + EVT VT = N->getValueType(0); + if (VT != MVT::i32) + return SDValue(); + + // The value and the mask need to be constants so we can verify this is + // actually a bitfield set. If the mask is 0xffff, we can do better + // via a movt instruction, so don't use BFI in that case. + ConstantSDNode *C = dyn_cast<ConstantSDNode>(N0.getOperand(1)); + if (!C) + return SDValue(); + unsigned Mask = C->getZExtValue(); + if (Mask == 0xffff) + return SDValue(); + C = dyn_cast<ConstantSDNode>(N1); + if (!C) + return SDValue(); + unsigned Val = C->getZExtValue(); + if (ARM::isBitFieldInvertedMask(Mask) && (Val & ~Mask) != Val) + return SDValue(); + Val >>= CountTrailingZeros_32(~Mask); + + DebugLoc DL = N->getDebugLoc(); + SDValue Res = DAG.getNode(ARMISD::BFI, DL, VT, N0.getOperand(0), + DAG.getConstant(Val, MVT::i32), + DAG.getConstant(Mask, MVT::i32)); + + // Do not add new nodes to DAG combiner worklist. + DCI.CombineTo(N, Res, false); + + return SDValue(); +} + /// PerformVMOVRRDCombine - Target-specific dag combine xforms for /// ARMISD::VMOVRRD. static SDValue PerformVMOVRRDCombine(SDNode *N, @@ -4649,6 +4699,7 @@ SDValue ARMTargetLowering::PerformDAGCombine(SDNode *N, case ISD::ADD: return PerformADDCombine(N, DCI); case ISD::SUB: return PerformSUBCombine(N, DCI); case ISD::MUL: return PerformMULCombine(N, DCI, Subtarget); + case ISD::OR: return PerformORCombine(N, DCI, Subtarget); case ARMISD::VMOVRRD: return PerformVMOVRRDCombine(N, DCI); case ARMISD::VDUPLANE: return PerformVDUPLANECombine(N, DCI); case ISD::INTRINSIC_WO_CHAIN: return PerformIntrinsicCombine(N, DCI.DAG); @@ -5380,6 +5431,21 @@ int ARM::getVFPf64Imm(const APFloat &FPImm) { return ((int)Sign << 7) | (Exp << 4) | Mantissa; } +bool ARM::isBitFieldInvertedMask(unsigned v) { + if (v == 0xffffffff) + return 0; + // there can be 1's on either or both "outsides", all the "inside" + // bits must be 0's + unsigned int lsb = 0, msb = 31; + while (v & (1 << msb)) --msb; + while (v & (1 << lsb)) ++lsb; + for (unsigned int i = lsb; i <= msb; ++i) { + if (v & (1 << i)) + return 0; + } + return 1; +} + /// isFPImmLegal - Returns true if the target can instruction select the /// specified FP immediate natively. If false, the legalizer will /// materialize the FP immediate as a load from a constant pool. |