//===-- AMDGPUISelLowering.cpp - AMDGPU Common DAG lowering functions -----===// // // The LLVM Compiler Infrastructure // // This file is distributed under the University of Illinois Open Source // License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// // // This is the parent TargetLowering class for hardware code gen targets. // //===----------------------------------------------------------------------===// #include "AMDGPUISelLowering.h" #include "AMDILIntrinsicInfo.h" #include "AMDGPUUtil.h" #include "llvm/CodeGen/MachineRegisterInfo.h" using namespace llvm; AMDGPUTargetLowering::AMDGPUTargetLowering(TargetMachine &TM) : AMDILTargetLowering(TM) { // We need to custom lower some of the intrinsics setOperationAction(ISD::INTRINSIC_WO_CHAIN, MVT::Other, Custom); // Library functions. These default to Expand, but we have instructions // for them. setOperationAction(ISD::FCEIL, MVT::f32, Legal); setOperationAction(ISD::FEXP2, MVT::f32, Legal); setOperationAction(ISD::FRINT, MVT::f32, Legal); setOperationAction(ISD::UDIV, MVT::i32, Expand); setOperationAction(ISD::UDIVREM, MVT::i32, Custom); setOperationAction(ISD::UREM, MVT::i32, Expand); } //===---------------------------------------------------------------------===// // TargetLowering Callbacks //===---------------------------------------------------------------------===// SDValue AMDGPUTargetLowering::LowerFormalArguments( SDValue Chain, CallingConv::ID CallConv, bool isVarArg, const SmallVectorImpl &Ins, DebugLoc DL, SelectionDAG &DAG, SmallVectorImpl &InVals) const { // Lowering of arguments happens in R600LowerKernelParameters, so we can // ignore the arguments here. for (unsigned i = 0, e = Ins.size(); i < e; ++i) { InVals.push_back(SDValue()); } return Chain; } SDValue AMDGPUTargetLowering::LowerReturn( SDValue Chain, CallingConv::ID CallConv, bool isVarArg, const SmallVectorImpl &Outs, const SmallVectorImpl &OutVals, DebugLoc DL, SelectionDAG &DAG) const { return DAG.getNode(AMDILISD::RET_FLAG, DL, MVT::Other, Chain); } //===---------------------------------------------------------------------===// // Target specific lowering //===---------------------------------------------------------------------===// SDValue AMDGPUTargetLowering::LowerOperation(SDValue Op, SelectionDAG &DAG) const { switch (Op.getOpcode()) { default: return AMDILTargetLowering::LowerOperation(Op, DAG); case ISD::INTRINSIC_WO_CHAIN: return LowerINTRINSIC_WO_CHAIN(Op, DAG); case ISD::UDIVREM: return LowerUDIVREM(Op, DAG); } } SDValue AMDGPUTargetLowering::LowerINTRINSIC_WO_CHAIN(SDValue Op, SelectionDAG &DAG) const { unsigned IntrinsicID = cast(Op.getOperand(0))->getZExtValue(); DebugLoc DL = Op.getDebugLoc(); EVT VT = Op.getValueType(); switch (IntrinsicID) { default: return Op; case AMDGPUIntrinsic::AMDIL_abs: return LowerIntrinsicIABS(Op, DAG); case AMDGPUIntrinsic::AMDIL_exp: return DAG.getNode(ISD::FEXP2, DL, VT, Op.getOperand(1)); case AMDGPUIntrinsic::AMDIL_fabs: return DAG.getNode(ISD::FABS, DL, VT, Op.getOperand(1)); case AMDGPUIntrinsic::AMDGPU_lrp: return LowerIntrinsicLRP(Op, DAG); case AMDGPUIntrinsic::AMDIL_fraction: return DAG.getNode(AMDGPUISD::FRACT, DL, VT, Op.getOperand(1)); case AMDGPUIntrinsic::AMDIL_mad: return DAG.getNode(AMDILISD::MAD, DL, VT, Op.getOperand(1), Op.getOperand(2), Op.getOperand(3)); case AMDGPUIntrinsic::AMDIL_max: return DAG.getNode(AMDGPUISD::FMAX, DL, VT, Op.getOperand(1), Op.getOperand(2)); case AMDGPUIntrinsic::AMDGPU_imax: return DAG.getNode(AMDGPUISD::SMAX, DL, VT, Op.getOperand(1), Op.getOperand(2)); case AMDGPUIntrinsic::AMDGPU_umax: return DAG.getNode(AMDGPUISD::UMAX, DL, VT, Op.getOperand(1), Op.getOperand(2)); case AMDGPUIntrinsic::AMDIL_min: return DAG.getNode(AMDGPUISD::FMIN, DL, VT, Op.getOperand(1), Op.getOperand(2)); case AMDGPUIntrinsic::AMDGPU_imin: return DAG.getNode(AMDGPUISD::SMIN, DL, VT, Op.getOperand(1), Op.getOperand(2)); case AMDGPUIntrinsic::AMDGPU_umin: return DAG.getNode(AMDGPUISD::UMIN, DL, VT, Op.getOperand(1), Op.getOperand(2)); case AMDGPUIntrinsic::AMDIL_round_nearest: return DAG.getNode(ISD::FRINT, DL, VT, Op.getOperand(1)); case AMDGPUIntrinsic::AMDIL_round_posinf: return DAG.getNode(ISD::FCEIL, DL, VT, Op.getOperand(1)); } } ///IABS(a) = SMAX(sub(0, a), a) SDValue AMDGPUTargetLowering::LowerIntrinsicIABS(SDValue Op, SelectionDAG &DAG) const { DebugLoc DL = Op.getDebugLoc(); EVT VT = Op.getValueType(); SDValue Neg = DAG.getNode(ISD::SUB, DL, VT, DAG.getConstant(0, VT), Op.getOperand(1)); return DAG.getNode(AMDGPUISD::SMAX, DL, VT, Neg, Op.getOperand(1)); } /// Linear Interpolation /// LRP(a, b, c) = muladd(a, b, (1 - a) * c) SDValue AMDGPUTargetLowering::LowerIntrinsicLRP(SDValue Op, SelectionDAG &DAG) const { DebugLoc DL = Op.getDebugLoc(); EVT VT = Op.getValueType(); SDValue OneSubA = DAG.getNode(ISD::FSUB, DL, VT, DAG.getConstantFP(1.0f, MVT::f32), Op.getOperand(1)); SDValue OneSubAC = DAG.getNode(ISD::FMUL, DL, VT, OneSubA, Op.getOperand(3)); return DAG.getNode(AMDILISD::MAD, DL, VT, Op.getOperand(1), Op.getOperand(2), OneSubAC); } SDValue AMDGPUTargetLowering::LowerUDIVREM(SDValue Op, SelectionDAG &DAG) const { DebugLoc DL = Op.getDebugLoc(); EVT VT = Op.getValueType(); SDValue Num = Op.getOperand(0); SDValue Den = Op.getOperand(1); SmallVector Results; // RCP = URECIP(Den) = 2^32 / Den + e // e is rounding error. SDValue RCP = DAG.getNode(AMDGPUISD::URECIP, DL, VT, Den); // RCP_LO = umulo(RCP, Den) */ SDValue RCP_LO = DAG.getNode(ISD::UMULO, DL, VT, RCP, Den); // RCP_HI = mulhu (RCP, Den) */ SDValue RCP_HI = DAG.getNode(ISD::MULHU, DL, VT, RCP, Den); // NEG_RCP_LO = -RCP_LO SDValue NEG_RCP_LO = DAG.getNode(ISD::SUB, DL, VT, DAG.getConstant(0, VT), RCP_LO); // ABS_RCP_LO = (RCP_HI == 0 ? NEG_RCP_LO : RCP_LO) SDValue ABS_RCP_LO = DAG.getSelectCC(DL, RCP_HI, DAG.getConstant(0, VT), NEG_RCP_LO, RCP_LO, ISD::SETEQ); // Calculate the rounding error from the URECIP instruction // E = mulhu(ABS_RCP_LO, RCP) SDValue E = DAG.getNode(ISD::MULHU, DL, VT, ABS_RCP_LO, RCP); // RCP_A_E = RCP + E SDValue RCP_A_E = DAG.getNode(ISD::ADD, DL, VT, RCP, E); // RCP_S_E = RCP - E SDValue RCP_S_E = DAG.getNode(ISD::SUB, DL, VT, RCP, E); // Tmp0 = (RCP_HI == 0 ? RCP_A_E : RCP_SUB_E) SDValue Tmp0 = DAG.getSelectCC(DL, RCP_HI, DAG.getConstant(0, VT), RCP_A_E, RCP_S_E, ISD::SETEQ); // Quotient = mulhu(Tmp0, Num) SDValue Quotient = DAG.getNode(ISD::MULHU, DL, VT, Tmp0, Num); // Num_S_Remainder = Quotient * Den SDValue Num_S_Remainder = DAG.getNode(ISD::UMULO, DL, VT, Quotient, Den); // Remainder = Num - Num_S_Remainder SDValue Remainder = DAG.getNode(ISD::SUB, DL, VT, Num, Num_S_Remainder); // Remainder_GE_Den = (Remainder >= Den ? -1 : 0) SDValue Remainder_GE_Den = DAG.getSelectCC(DL, Remainder, Den, DAG.getConstant(-1, VT), DAG.getConstant(0, VT), ISD::SETGE); // Remainder_GE_Zero = (Remainder >= 0 ? -1 : 0) SDValue Remainder_GE_Zero = DAG.getSelectCC(DL, Remainder, DAG.getConstant(0, VT), DAG.getConstant(-1, VT), DAG.getConstant(0, VT), ISD::SETGE); // Tmp1 = Remainder_GE_Den & Remainder_GE_Zero SDValue Tmp1 = DAG.getNode(ISD::AND, DL, VT, Remainder_GE_Den, Remainder_GE_Zero); // Calculate Division result: // Quotient_A_One = Quotient + 1 SDValue Quotient_A_One = DAG.getNode(ISD::ADD, DL, VT, Quotient, DAG.getConstant(1, VT)); // Quotient_S_One = Quotient - 1 SDValue Quotient_S_One = DAG.getNode(ISD::SUB, DL, VT, Quotient, DAG.getConstant(1, VT)); // Div = (Tmp1 == 0 ? Quotient : Quotient_A_One) SDValue Div = DAG.getSelectCC(DL, Tmp1, DAG.getConstant(0, VT), Quotient, Quotient_A_One, ISD::SETEQ); // Div = (Remainder_GE_Zero == 0 ? Quotient_S_One : Div) Div = DAG.getSelectCC(DL, Remainder_GE_Zero, DAG.getConstant(0, VT), Quotient_S_One, Div, ISD::SETEQ); // Calculate Rem result: // Remainder_S_Den = Remainder - Den SDValue Remainder_S_Den = DAG.getNode(ISD::SUB, DL, VT, Remainder, Den); // Remainder_A_Den = Remainder + Den SDValue Remainder_A_Den = DAG.getNode(ISD::ADD, DL, VT, Remainder, Den); // Rem = (Tmp1 == 0 ? Remainder : Remainder_S_Den) SDValue Rem = DAG.getSelectCC(DL, Tmp1, DAG.getConstant(0, VT), Remainder, Remainder_S_Den, ISD::SETEQ); // Rem = (Remainder_GE_Zero == 0 ? Remainder_A_Den : Rem) Rem = DAG.getSelectCC(DL, Remainder_GE_Zero, DAG.getConstant(0, VT), Remainder_A_Den, Rem, ISD::SETEQ); DAG.ReplaceAllUsesWith(Op.getValue(0).getNode(), &Div); DAG.ReplaceAllUsesWith(Op.getValue(1).getNode(), &Rem); return Op; } //===----------------------------------------------------------------------===// // Helper functions //===----------------------------------------------------------------------===// bool AMDGPUTargetLowering::isHWTrueValue(SDValue Op) const { if (ConstantFPSDNode * CFP = dyn_cast(Op)) { return CFP->isExactlyValue(1.0); } if (ConstantSDNode *C = dyn_cast(Op)) { return C->isAllOnesValue(); } return false; } bool AMDGPUTargetLowering::isHWFalseValue(SDValue Op) const { if (ConstantFPSDNode * CFP = dyn_cast(Op)) { return CFP->getValueAPF().isZero(); } if (ConstantSDNode *C = dyn_cast(Op)) { return C->isNullValue(); } return false; } void AMDGPUTargetLowering::addLiveIn(MachineInstr * MI, MachineFunction * MF, MachineRegisterInfo & MRI, const TargetInstrInfo * TII, unsigned reg) const { AMDGPU::utilAddLiveIn(MF, MRI, TII, reg, MI->getOperand(0).getReg()); } #define NODE_NAME_CASE(node) case AMDGPUISD::node: return #node; const char* AMDGPUTargetLowering::getTargetNodeName(unsigned Opcode) const { switch (Opcode) { default: return AMDILTargetLowering::getTargetNodeName(Opcode); NODE_NAME_CASE(FRACT) NODE_NAME_CASE(FMAX) NODE_NAME_CASE(SMAX) NODE_NAME_CASE(UMAX) NODE_NAME_CASE(FMIN) NODE_NAME_CASE(SMIN) NODE_NAME_CASE(UMIN) NODE_NAME_CASE(URECIP) } }