| //===- R600ExpandSpecialInstrs.cpp - Expand special instructions ----------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| /// \file |
| /// Vector, Reduction, and Cube instructions need to fill the entire instruction |
| /// group to work correctly. This pass expands these individual instructions |
| /// into several instructions that will completely fill the instruction group. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "AMDGPU.h" |
| #include "AMDGPUSubtarget.h" |
| #include "R600Defines.h" |
| #include "R600InstrInfo.h" |
| #include "R600RegisterInfo.h" |
| #include "llvm/CodeGen/MachineBasicBlock.h" |
| #include "llvm/CodeGen/MachineFunction.h" |
| #include "MCTargetDesc/AMDGPUMCTargetDesc.h" |
| #include "llvm/CodeGen/MachineFunctionPass.h" |
| #include "llvm/CodeGen/MachineInstr.h" |
| #include "llvm/CodeGen/MachineInstrBuilder.h" |
| #include "llvm/CodeGen/MachineOperand.h" |
| #include "llvm/Pass.h" |
| #include <cassert> |
| #include <cstdint> |
| #include <iterator> |
| |
| using namespace llvm; |
| |
| #define DEBUG_TYPE "r600-expand-special-instrs" |
| |
| namespace { |
| |
| class R600ExpandSpecialInstrsPass : public MachineFunctionPass { |
| private: |
| const R600InstrInfo *TII = nullptr; |
| |
| void SetFlagInNewMI(MachineInstr *NewMI, const MachineInstr *OldMI, |
| unsigned Op); |
| |
| public: |
| static char ID; |
| |
| R600ExpandSpecialInstrsPass() : MachineFunctionPass(ID) {} |
| |
| bool runOnMachineFunction(MachineFunction &MF) override; |
| |
| StringRef getPassName() const override { |
| return "R600 Expand special instructions pass"; |
| } |
| }; |
| |
| } // end anonymous namespace |
| |
| INITIALIZE_PASS_BEGIN(R600ExpandSpecialInstrsPass, DEBUG_TYPE, |
| "R600 Expand Special Instrs", false, false) |
| INITIALIZE_PASS_END(R600ExpandSpecialInstrsPass, DEBUG_TYPE, |
| "R600ExpandSpecialInstrs", false, false) |
| |
| char R600ExpandSpecialInstrsPass::ID = 0; |
| |
| char &llvm::R600ExpandSpecialInstrsPassID = R600ExpandSpecialInstrsPass::ID; |
| |
| FunctionPass *llvm::createR600ExpandSpecialInstrsPass() { |
| return new R600ExpandSpecialInstrsPass(); |
| } |
| |
| void R600ExpandSpecialInstrsPass::SetFlagInNewMI(MachineInstr *NewMI, |
| const MachineInstr *OldMI, unsigned Op) { |
| int OpIdx = TII->getOperandIdx(*OldMI, Op); |
| if (OpIdx > -1) { |
| uint64_t Val = OldMI->getOperand(OpIdx).getImm(); |
| TII->setImmOperand(*NewMI, Op, Val); |
| } |
| } |
| |
| bool R600ExpandSpecialInstrsPass::runOnMachineFunction(MachineFunction &MF) { |
| const R600Subtarget &ST = MF.getSubtarget<R600Subtarget>(); |
| TII = ST.getInstrInfo(); |
| |
| const R600RegisterInfo &TRI = TII->getRegisterInfo(); |
| |
| for (MachineFunction::iterator BB = MF.begin(), BB_E = MF.end(); |
| BB != BB_E; ++BB) { |
| MachineBasicBlock &MBB = *BB; |
| MachineBasicBlock::iterator I = MBB.begin(); |
| while (I != MBB.end()) { |
| MachineInstr &MI = *I; |
| I = std::next(I); |
| |
| // Expand LDS_*_RET instructions |
| if (TII->isLDSRetInstr(MI.getOpcode())) { |
| int DstIdx = TII->getOperandIdx(MI.getOpcode(), R600::OpName::dst); |
| assert(DstIdx != -1); |
| MachineOperand &DstOp = MI.getOperand(DstIdx); |
| MachineInstr *Mov = TII->buildMovInstr(&MBB, I, |
| DstOp.getReg(), R600::OQAP); |
| DstOp.setReg(R600::OQAP); |
| int LDSPredSelIdx = TII->getOperandIdx(MI.getOpcode(), |
| R600::OpName::pred_sel); |
| int MovPredSelIdx = TII->getOperandIdx(Mov->getOpcode(), |
| R600::OpName::pred_sel); |
| // Copy the pred_sel bit |
| Mov->getOperand(MovPredSelIdx).setReg( |
| MI.getOperand(LDSPredSelIdx).getReg()); |
| } |
| |
| switch (MI.getOpcode()) { |
| default: break; |
| // Expand PRED_X to one of the PRED_SET instructions. |
| case R600::PRED_X: { |
| uint64_t Flags = MI.getOperand(3).getImm(); |
| // The native opcode used by PRED_X is stored as an immediate in the |
| // third operand. |
| MachineInstr *PredSet = TII->buildDefaultInstruction(MBB, I, |
| MI.getOperand(2).getImm(), // opcode |
| MI.getOperand(0).getReg(), // dst |
| MI.getOperand(1).getReg(), // src0 |
| R600::ZERO); // src1 |
| TII->addFlag(*PredSet, 0, MO_FLAG_MASK); |
| if (Flags & MO_FLAG_PUSH) { |
| TII->setImmOperand(*PredSet, R600::OpName::update_exec_mask, 1); |
| } else { |
| TII->setImmOperand(*PredSet, R600::OpName::update_pred, 1); |
| } |
| MI.eraseFromParent(); |
| continue; |
| } |
| case R600::DOT_4: { |
| |
| const R600RegisterInfo &TRI = TII->getRegisterInfo(); |
| |
| Register DstReg = MI.getOperand(0).getReg(); |
| unsigned DstBase = TRI.getEncodingValue(DstReg) & HW_REG_MASK; |
| |
| for (unsigned Chan = 0; Chan < 4; ++Chan) { |
| bool Mask = (Chan != TRI.getHWRegChan(DstReg)); |
| unsigned SubDstReg = |
| R600::R600_TReg32RegClass.getRegister((DstBase * 4) + Chan); |
| MachineInstr *BMI = |
| TII->buildSlotOfVectorInstruction(MBB, &MI, Chan, SubDstReg); |
| if (Chan > 0) { |
| BMI->bundleWithPred(); |
| } |
| if (Mask) { |
| TII->addFlag(*BMI, 0, MO_FLAG_MASK); |
| } |
| if (Chan != 3) |
| TII->addFlag(*BMI, 0, MO_FLAG_NOT_LAST); |
| unsigned Opcode = BMI->getOpcode(); |
| // While not strictly necessary from hw point of view, we force |
| // all src operands of a dot4 inst to belong to the same slot. |
| Register Src0 = |
| BMI->getOperand(TII->getOperandIdx(Opcode, R600::OpName::src0)) |
| .getReg(); |
| Register Src1 = |
| BMI->getOperand(TII->getOperandIdx(Opcode, R600::OpName::src1)) |
| .getReg(); |
| (void) Src0; |
| (void) Src1; |
| if ((TRI.getEncodingValue(Src0) & 0xff) < 127 && |
| (TRI.getEncodingValue(Src1) & 0xff) < 127) |
| assert(TRI.getHWRegChan(Src0) == TRI.getHWRegChan(Src1)); |
| } |
| MI.eraseFromParent(); |
| continue; |
| } |
| } |
| |
| bool IsReduction = TII->isReductionOp(MI.getOpcode()); |
| bool IsVector = TII->isVector(MI); |
| bool IsCube = TII->isCubeOp(MI.getOpcode()); |
| if (!IsReduction && !IsVector && !IsCube) { |
| continue; |
| } |
| |
| // Expand the instruction |
| // |
| // Reduction instructions: |
| // T0_X = DP4 T1_XYZW, T2_XYZW |
| // becomes: |
| // TO_X = DP4 T1_X, T2_X |
| // TO_Y (write masked) = DP4 T1_Y, T2_Y |
| // TO_Z (write masked) = DP4 T1_Z, T2_Z |
| // TO_W (write masked) = DP4 T1_W, T2_W |
| // |
| // Vector instructions: |
| // T0_X = MULLO_INT T1_X, T2_X |
| // becomes: |
| // T0_X = MULLO_INT T1_X, T2_X |
| // T0_Y (write masked) = MULLO_INT T1_X, T2_X |
| // T0_Z (write masked) = MULLO_INT T1_X, T2_X |
| // T0_W (write masked) = MULLO_INT T1_X, T2_X |
| // |
| // Cube instructions: |
| // T0_XYZW = CUBE T1_XYZW |
| // becomes: |
| // TO_X = CUBE T1_Z, T1_Y |
| // T0_Y = CUBE T1_Z, T1_X |
| // T0_Z = CUBE T1_X, T1_Z |
| // T0_W = CUBE T1_Y, T1_Z |
| for (unsigned Chan = 0; Chan < 4; Chan++) { |
| Register DstReg = |
| MI.getOperand(TII->getOperandIdx(MI, R600::OpName::dst)).getReg(); |
| Register Src0 = |
| MI.getOperand(TII->getOperandIdx(MI, R600::OpName::src0)).getReg(); |
| unsigned Src1 = 0; |
| |
| // Determine the correct source registers |
| if (!IsCube) { |
| int Src1Idx = TII->getOperandIdx(MI, R600::OpName::src1); |
| if (Src1Idx != -1) { |
| Src1 = MI.getOperand(Src1Idx).getReg(); |
| } |
| } |
| if (IsReduction) { |
| unsigned SubRegIndex = AMDGPURegisterInfo::getSubRegFromChannel(Chan); |
| Src0 = TRI.getSubReg(Src0, SubRegIndex); |
| Src1 = TRI.getSubReg(Src1, SubRegIndex); |
| } else if (IsCube) { |
| static const int CubeSrcSwz[] = {2, 2, 0, 1}; |
| unsigned SubRegIndex0 = AMDGPURegisterInfo::getSubRegFromChannel(CubeSrcSwz[Chan]); |
| unsigned SubRegIndex1 = AMDGPURegisterInfo::getSubRegFromChannel(CubeSrcSwz[3 - Chan]); |
| Src1 = TRI.getSubReg(Src0, SubRegIndex1); |
| Src0 = TRI.getSubReg(Src0, SubRegIndex0); |
| } |
| |
| // Determine the correct destination registers; |
| bool Mask = false; |
| bool NotLast = true; |
| if (IsCube) { |
| unsigned SubRegIndex = AMDGPURegisterInfo::getSubRegFromChannel(Chan); |
| DstReg = TRI.getSubReg(DstReg, SubRegIndex); |
| } else { |
| // Mask the write if the original instruction does not write to |
| // the current Channel. |
| Mask = (Chan != TRI.getHWRegChan(DstReg)); |
| unsigned DstBase = TRI.getEncodingValue(DstReg) & HW_REG_MASK; |
| DstReg = R600::R600_TReg32RegClass.getRegister((DstBase * 4) + Chan); |
| } |
| |
| // Set the IsLast bit |
| NotLast = (Chan != 3 ); |
| |
| // Add the new instruction |
| unsigned Opcode = MI.getOpcode(); |
| switch (Opcode) { |
| case R600::CUBE_r600_pseudo: |
| Opcode = R600::CUBE_r600_real; |
| break; |
| case R600::CUBE_eg_pseudo: |
| Opcode = R600::CUBE_eg_real; |
| break; |
| default: |
| break; |
| } |
| |
| MachineInstr *NewMI = |
| TII->buildDefaultInstruction(MBB, I, Opcode, DstReg, Src0, Src1); |
| |
| if (Chan != 0) |
| NewMI->bundleWithPred(); |
| if (Mask) { |
| TII->addFlag(*NewMI, 0, MO_FLAG_MASK); |
| } |
| if (NotLast) { |
| TII->addFlag(*NewMI, 0, MO_FLAG_NOT_LAST); |
| } |
| SetFlagInNewMI(NewMI, &MI, R600::OpName::clamp); |
| SetFlagInNewMI(NewMI, &MI, R600::OpName::literal); |
| SetFlagInNewMI(NewMI, &MI, R600::OpName::src0_abs); |
| SetFlagInNewMI(NewMI, &MI, R600::OpName::src1_abs); |
| SetFlagInNewMI(NewMI, &MI, R600::OpName::src0_neg); |
| SetFlagInNewMI(NewMI, &MI, R600::OpName::src1_neg); |
| } |
| MI.eraseFromParent(); |
| } |
| } |
| return false; |
| } |
