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Diffstat (limited to 'contrib/llvm/lib/Target/R600/AMDGPUIndirectAddressing.cpp')
| -rw-r--r-- | contrib/llvm/lib/Target/R600/AMDGPUIndirectAddressing.cpp | 343 |
1 files changed, 343 insertions, 0 deletions
diff --git a/contrib/llvm/lib/Target/R600/AMDGPUIndirectAddressing.cpp b/contrib/llvm/lib/Target/R600/AMDGPUIndirectAddressing.cpp new file mode 100644 index 000000000000..ed6c8ec55dd2 --- /dev/null +++ b/contrib/llvm/lib/Target/R600/AMDGPUIndirectAddressing.cpp @@ -0,0 +1,343 @@ +//===-- AMDGPUIndirectAddressing.cpp - Indirect Adressing Support ---------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +/// \file +/// +/// Instructions can use indirect addressing to index the register file as if it +/// were memory. This pass lowers RegisterLoad and RegisterStore instructions +/// to either a COPY or a MOV that uses indirect addressing. +// +//===----------------------------------------------------------------------===// + +#include "AMDGPU.h" +#include "R600InstrInfo.h" +#include "R600MachineFunctionInfo.h" +#include "llvm/CodeGen/MachineFunction.h" +#include "llvm/CodeGen/MachineFunctionPass.h" +#include "llvm/CodeGen/MachineInstrBuilder.h" +#include "llvm/CodeGen/MachineRegisterInfo.h" +#include "llvm/Support/Debug.h" + +using namespace llvm; + +namespace { + +class AMDGPUIndirectAddressingPass : public MachineFunctionPass { + +private: + static char ID; + const AMDGPUInstrInfo *TII; + + bool regHasExplicitDef(MachineRegisterInfo &MRI, unsigned Reg) const; + +public: + AMDGPUIndirectAddressingPass(TargetMachine &tm) : + MachineFunctionPass(ID), + TII(static_cast<const AMDGPUInstrInfo*>(tm.getInstrInfo())) + { } + + virtual bool runOnMachineFunction(MachineFunction &MF); + + const char *getPassName() const { return "R600 Handle indirect addressing"; } + +}; + +} // End anonymous namespace + +char AMDGPUIndirectAddressingPass::ID = 0; + +FunctionPass *llvm::createAMDGPUIndirectAddressingPass(TargetMachine &tm) { + return new AMDGPUIndirectAddressingPass(tm); +} + +bool AMDGPUIndirectAddressingPass::runOnMachineFunction(MachineFunction &MF) { + MachineRegisterInfo &MRI = MF.getRegInfo(); + + int IndirectBegin = TII->getIndirectIndexBegin(MF); + int IndirectEnd = TII->getIndirectIndexEnd(MF); + + if (IndirectBegin == -1) { + // No indirect addressing, we can skip this pass + assert(IndirectEnd == -1); + return false; + } + + // The map keeps track of the indirect address that is represented by + // each virtual register. The key is the register and the value is the + // indirect address it uses. + std::map<unsigned, unsigned> RegisterAddressMap; + + // First pass - Lower all of the RegisterStore instructions and track which + // registers are live. + for (MachineFunction::iterator BB = MF.begin(), BB_E = MF.end(); + BB != BB_E; ++BB) { + // This map keeps track of the current live indirect registers. + // The key is the address and the value is the register + std::map<unsigned, unsigned> LiveAddressRegisterMap; + MachineBasicBlock &MBB = *BB; + + for (MachineBasicBlock::iterator I = MBB.begin(), Next = llvm::next(I); + I != MBB.end(); I = Next) { + Next = llvm::next(I); + MachineInstr &MI = *I; + + if (!TII->isRegisterStore(MI)) { + continue; + } + + // Lower RegisterStore + + unsigned RegIndex = MI.getOperand(2).getImm(); + unsigned Channel = MI.getOperand(3).getImm(); + unsigned Address = TII->calculateIndirectAddress(RegIndex, Channel); + const TargetRegisterClass *IndirectStoreRegClass = + TII->getIndirectAddrStoreRegClass(MI.getOperand(0).getReg()); + + if (MI.getOperand(1).getReg() == AMDGPU::INDIRECT_BASE_ADDR) { + // Direct register access. + unsigned DstReg = MRI.createVirtualRegister(IndirectStoreRegClass); + + BuildMI(MBB, I, MBB.findDebugLoc(I), TII->get(AMDGPU::COPY), DstReg) + .addOperand(MI.getOperand(0)); + + RegisterAddressMap[DstReg] = Address; + LiveAddressRegisterMap[Address] = DstReg; + } else { + // Indirect register access. + MachineInstrBuilder MOV = TII->buildIndirectWrite(BB, I, + MI.getOperand(0).getReg(), // Value + Address, + MI.getOperand(1).getReg()); // Offset + for (int i = IndirectBegin; i <= IndirectEnd; ++i) { + unsigned Addr = TII->calculateIndirectAddress(i, Channel); + unsigned DstReg = MRI.createVirtualRegister(IndirectStoreRegClass); + MOV.addReg(DstReg, RegState::Define | RegState::Implicit); + RegisterAddressMap[DstReg] = Addr; + LiveAddressRegisterMap[Addr] = DstReg; + } + } + MI.eraseFromParent(); + } + + // Update the live-ins of the succesor blocks + for (MachineBasicBlock::succ_iterator Succ = MBB.succ_begin(), + SuccEnd = MBB.succ_end(); + SuccEnd != Succ; ++Succ) { + std::map<unsigned, unsigned>::const_iterator Key, KeyEnd; + for (Key = LiveAddressRegisterMap.begin(), + KeyEnd = LiveAddressRegisterMap.end(); KeyEnd != Key; ++Key) { + (*Succ)->addLiveIn(Key->second); + } + } + } + + // Second pass - Lower the RegisterLoad instructions + for (MachineFunction::iterator BB = MF.begin(), BB_E = MF.end(); + BB != BB_E; ++BB) { + // Key is the address and the value is the register + std::map<unsigned, unsigned> LiveAddressRegisterMap; + MachineBasicBlock &MBB = *BB; + + MachineBasicBlock::livein_iterator LI = MBB.livein_begin(); + while (LI != MBB.livein_end()) { + std::vector<unsigned> PhiRegisters; + + // Make sure this live in is used for indirect addressing + if (RegisterAddressMap.find(*LI) == RegisterAddressMap.end()) { + ++LI; + continue; + } + + unsigned Address = RegisterAddressMap[*LI]; + LiveAddressRegisterMap[Address] = *LI; + PhiRegisters.push_back(*LI); + + // Check if there are other live in registers which map to the same + // indirect address. + for (MachineBasicBlock::livein_iterator LJ = llvm::next(LI), + LE = MBB.livein_end(); + LJ != LE; ++LJ) { + unsigned Reg = *LJ; + if (RegisterAddressMap.find(Reg) == RegisterAddressMap.end()) { + continue; + } + + if (RegisterAddressMap[Reg] == Address) { + PhiRegisters.push_back(Reg); + } + } + + if (PhiRegisters.size() == 1) { + // We don't need to insert a Phi instruction, so we can just add the + // registers to the live list for the block. + LiveAddressRegisterMap[Address] = *LI; + MBB.removeLiveIn(*LI); + } else { + // We need to insert a PHI, because we have the same address being + // written in multiple predecessor blocks. + const TargetRegisterClass *PhiDstClass = + TII->getIndirectAddrStoreRegClass(*(PhiRegisters.begin())); + unsigned PhiDstReg = MRI.createVirtualRegister(PhiDstClass); + MachineInstrBuilder Phi = BuildMI(MBB, MBB.begin(), + MBB.findDebugLoc(MBB.begin()), + TII->get(AMDGPU::PHI), PhiDstReg); + + for (std::vector<unsigned>::const_iterator RI = PhiRegisters.begin(), + RE = PhiRegisters.end(); + RI != RE; ++RI) { + unsigned Reg = *RI; + MachineInstr *DefInst = MRI.getVRegDef(Reg); + assert(DefInst); + MachineBasicBlock *RegBlock = DefInst->getParent(); + Phi.addReg(Reg); + Phi.addMBB(RegBlock); + MBB.removeLiveIn(Reg); + } + RegisterAddressMap[PhiDstReg] = Address; + LiveAddressRegisterMap[Address] = PhiDstReg; + } + LI = MBB.livein_begin(); + } + + for (MachineBasicBlock::iterator I = MBB.begin(), Next = llvm::next(I); + I != MBB.end(); I = Next) { + Next = llvm::next(I); + MachineInstr &MI = *I; + + if (!TII->isRegisterLoad(MI)) { + if (MI.getOpcode() == AMDGPU::PHI) { + continue; + } + // Check for indirect register defs + for (unsigned OpIdx = 0, NumOperands = MI.getNumOperands(); + OpIdx < NumOperands; ++OpIdx) { + MachineOperand &MO = MI.getOperand(OpIdx); + if (MO.isReg() && MO.isDef() && + RegisterAddressMap.find(MO.getReg()) != RegisterAddressMap.end()) { + unsigned Reg = MO.getReg(); + unsigned LiveAddress = RegisterAddressMap[Reg]; + // Chain the live-ins + if (LiveAddressRegisterMap.find(LiveAddress) != + RegisterAddressMap.end()) { + MI.addOperand(MachineOperand::CreateReg( + LiveAddressRegisterMap[LiveAddress], + false, // isDef + true, // isImp + true)); // isKill + } + LiveAddressRegisterMap[LiveAddress] = Reg; + } + } + continue; + } + + const TargetRegisterClass *SuperIndirectRegClass = + TII->getSuperIndirectRegClass(); + const TargetRegisterClass *IndirectLoadRegClass = + TII->getIndirectAddrLoadRegClass(); + unsigned IndirectReg = MRI.createVirtualRegister(SuperIndirectRegClass); + + unsigned RegIndex = MI.getOperand(2).getImm(); + unsigned Channel = MI.getOperand(3).getImm(); + unsigned Address = TII->calculateIndirectAddress(RegIndex, Channel); + + if (MI.getOperand(1).getReg() == AMDGPU::INDIRECT_BASE_ADDR) { + // Direct register access + unsigned Reg = LiveAddressRegisterMap[Address]; + unsigned AddrReg = IndirectLoadRegClass->getRegister(Address); + + if (regHasExplicitDef(MRI, Reg)) { + // If the register we are reading from has an explicit def, then that + // means it was written via a direct register access (i.e. COPY + // or other instruction that doesn't use indirect addressing). In + // this case we know where the value has been stored, so we can just + // issue a copy. + BuildMI(MBB, I, MBB.findDebugLoc(I), TII->get(AMDGPU::COPY), + MI.getOperand(0).getReg()) + .addReg(Reg); + } else { + // If the register we are reading has an implicit def, then that + // means it was written by an indirect register access (i.e. An + // instruction that uses indirect addressing. + BuildMI(MBB, I, MBB.findDebugLoc(I), TII->get(AMDGPU::COPY), + MI.getOperand(0).getReg()) + .addReg(AddrReg) + .addReg(Reg, RegState::Implicit); + } + } else { + // Indirect register access + + // Note on REQ_SEQUENCE instructons: You can't actually use the register + // it defines unless you have an instruction that takes the defined + // register class as an operand. + + MachineInstrBuilder Sequence = BuildMI(MBB, I, MBB.findDebugLoc(I), + TII->get(AMDGPU::REG_SEQUENCE), + IndirectReg); + for (int i = IndirectBegin; i <= IndirectEnd; ++i) { + unsigned Addr = TII->calculateIndirectAddress(i, Channel); + if (LiveAddressRegisterMap.find(Addr) == LiveAddressRegisterMap.end()) { + continue; + } + unsigned Reg = LiveAddressRegisterMap[Addr]; + + // We only need to use REG_SEQUENCE for explicit defs, since the + // register coalescer won't do anything with the implicit defs. + if (!regHasExplicitDef(MRI, Reg)) { + continue; + } + + // Insert a REQ_SEQUENCE instruction to force the register allocator + // to allocate the virtual register to the correct physical register. + Sequence.addReg(LiveAddressRegisterMap[Addr]); + Sequence.addImm(TII->getRegisterInfo().getIndirectSubReg(Addr)); + } + MachineInstrBuilder Mov = TII->buildIndirectRead(BB, I, + MI.getOperand(0).getReg(), // Value + Address, + MI.getOperand(1).getReg()); // Offset + + + + Mov.addReg(IndirectReg, RegState::Implicit | RegState::Kill); + Mov.addReg(LiveAddressRegisterMap[Address], RegState::Implicit); + + } + MI.eraseFromParent(); + } + } + return false; +} + +bool AMDGPUIndirectAddressingPass::regHasExplicitDef(MachineRegisterInfo &MRI, + unsigned Reg) const { + MachineInstr *DefInstr = MRI.getVRegDef(Reg); + + if (!DefInstr) { + return false; + } + + if (DefInstr->getOpcode() == AMDGPU::PHI) { + bool Explicit = false; + for (MachineInstr::const_mop_iterator I = DefInstr->operands_begin(), + E = DefInstr->operands_end(); + I != E; ++I) { + const MachineOperand &MO = *I; + if (!MO.isReg() || MO.isDef()) { + continue; + } + + Explicit = Explicit || regHasExplicitDef(MRI, MO.getReg()); + } + return Explicit; + } + + return DefInstr->getOperand(0).isReg() && + DefInstr->getOperand(0).getReg() == Reg; +} |