From 8b02910abc4a18fb4670e8bc678357d7f1f4998d Mon Sep 17 00:00:00 2001 From: Tom Stellard Date: Thu, 29 Aug 2013 11:43:01 -0700 Subject: [PATCH] XXX: WIP Register spilling v3 v2: - Fix encoding of Lane Mask - Use correct register flags, so we don't overwrite the low dword when restoring multi-dword registers. v3: - Register spilling seems to hang the GPU, so replace all shaders that need spilling with a dummy shader. --- lib/Target/R600/AMDGPUInstrInfo.h | 20 ++++----- lib/Target/R600/SIInstrInfo.cpp | 75 +++++++++++++++++++++++++++++++ lib/Target/R600/SIInstrInfo.h | 12 +++++ lib/Target/R600/SILowerControlFlow.cpp | 24 ++++++++++ lib/Target/R600/SIMachineFunctionInfo.cpp | 35 ++++++++++++++- lib/Target/R600/SIMachineFunctionInfo.h | 28 ++++++++++++ lib/Target/R600/SIRegisterInfo.cpp | 20 +++++++++ lib/Target/R600/SIRegisterInfo.h | 1 + 8 files changed, 204 insertions(+), 11 deletions(-) diff --git a/lib/Target/R600/AMDGPUInstrInfo.h b/lib/Target/R600/AMDGPUInstrInfo.h index ce5b58c..426910c 100644 --- a/lib/Target/R600/AMDGPUInstrInfo.h +++ b/lib/Target/R600/AMDGPUInstrInfo.h @@ -78,18 +78,18 @@ public: unsigned DestReg, unsigned SrcReg, bool KillSrc) const = 0; - void storeRegToStackSlot(MachineBasicBlock &MBB, - MachineBasicBlock::iterator MI, - unsigned SrcReg, bool isKill, int FrameIndex, - const TargetRegisterClass *RC, - const TargetRegisterInfo *TRI) const; - void loadRegFromStackSlot(MachineBasicBlock &MBB, - MachineBasicBlock::iterator MI, - unsigned DestReg, int FrameIndex, - const TargetRegisterClass *RC, - const TargetRegisterInfo *TRI) const; virtual bool expandPostRAPseudo(MachineBasicBlock::iterator MI) const; + virtual void storeRegToStackSlot(MachineBasicBlock &MBB, + MachineBasicBlock::iterator MI, + unsigned SrcReg, bool isKill, int FrameIndex, + const TargetRegisterClass *RC, + const TargetRegisterInfo *TRI) const; + virtual void loadRegFromStackSlot(MachineBasicBlock &MBB, + MachineBasicBlock::iterator MI, + unsigned DestReg, int FrameIndex, + const TargetRegisterClass *RC, + const TargetRegisterInfo *TRI) const; protected: MachineInstr *foldMemoryOperandImpl(MachineFunction &MF, diff --git a/lib/Target/R600/SIInstrInfo.cpp b/lib/Target/R600/SIInstrInfo.cpp index ab55c1b..61220ae 100644 --- a/lib/Target/R600/SIInstrInfo.cpp +++ b/lib/Target/R600/SIInstrInfo.cpp @@ -16,6 +16,7 @@ #include "SIInstrInfo.h" #include "AMDGPUTargetMachine.h" #include "SIDefines.h" +#include "SIMachineFunctionInfo.h" #include "llvm/CodeGen/MachineInstrBuilder.h" #include "llvm/CodeGen/MachineRegisterInfo.h" #include "llvm/MC/MCInstrDesc.h" @@ -185,6 +186,80 @@ unsigned SIInstrInfo::commuteOpcode(unsigned Opcode) const { return Opcode; } +void SIInstrInfo::storeRegToStackSlot(MachineBasicBlock &MBB, + MachineBasicBlock::iterator MI, + unsigned SrcReg, bool isKill, + int FrameIndex, + const TargetRegisterClass *RC, + const TargetRegisterInfo *TRI) const { + MachineRegisterInfo &MRI = MBB.getParent()->getRegInfo(); + SIMachineFunctionInfo *MFI = MBB.getParent()->getInfo(); + DebugLoc DL = MBB.findDebugLoc(MI); + unsigned KillFlag = isKill ? RegState::Kill : 0; + + if (RC == &AMDGPU::SReg_32RegClass) { + if (RI.allUsesCanBeCopiedToVGPR(MRI, MI->getOperand(0).getReg())) { + unsigned VReg = MRI.createVirtualRegister(&AMDGPU::VReg_32RegClass); + BuildMI(MBB, MI, DL, get(AMDGPU::COPY), VReg) + .addReg(SrcReg, KillFlag); + MFI->SpillTracker.addSpilledReg(FrameIndex, VReg); + } else { + unsigned Lane = MFI->SpillTracker.getNextLane(MRI); + BuildMI(MBB, MI, DL, get(AMDGPU::V_WRITELANE_B32_e32), + MFI->SpillTracker.LaneVGPR) + .addReg(SrcReg, KillFlag) + .addImm(Lane + 0x80); + MFI->SpillTracker.addSpilledReg(FrameIndex, MFI->SpillTracker.LaneVGPR, + Lane); + } + } else { + for (unsigned i = 0, e = RC->getSize() / 4; i != e; ++i) { + unsigned SubReg = MRI.createVirtualRegister(&AMDGPU::SReg_32RegClass); + BuildMI(MBB, MI, MBB.findDebugLoc(MI), get(AMDGPU::COPY), SubReg) + .addReg(SrcReg, 0, RI.getSubRegFromChannel(i)); + storeRegToStackSlot(MBB, MI, SubReg, isKill, FrameIndex + i, + &AMDGPU::SReg_32RegClass, TRI); + } + } +} + +void SIInstrInfo::loadRegFromStackSlot(MachineBasicBlock &MBB, + MachineBasicBlock::iterator MI, + unsigned DestReg, int FrameIndex, + const TargetRegisterClass *RC, + const TargetRegisterInfo *TRI) const { + MachineRegisterInfo &MRI = MBB.getParent()->getRegInfo(); + SIMachineFunctionInfo *MFI = MBB.getParent()->getInfo(); + DebugLoc DL = MBB.findDebugLoc(MI); + if (RC == &AMDGPU::SReg_32RegClass) { + SIMachineFunctionInfo::SpilledReg Spill = + MFI->SpillTracker.getSpilledReg(FrameIndex); + assert(Spill.VGPR); + if (!Spill.hasLane()) { + MRI.setRegClass(DestReg, MRI.getRegClass(Spill.VGPR)); + BuildMI(MBB, MI, DL, get(AMDGPU::COPY), DestReg) + .addReg(Spill.VGPR); + } else { + BuildMI(MBB, MI, DL, get(AMDGPU::V_READLANE_B32_e32), DestReg) + .addReg(Spill.VGPR) + .addImm(Spill.Lane + 0x80); + } + } else { + for (unsigned i = 0, e = RC->getSize() / 4; i != e; ++i) { + unsigned Flags = RegState::Define; + if (i == 0) { + Flags |= RegState::Undef; + } + unsigned SubReg = MRI.createVirtualRegister(&AMDGPU::SReg_32RegClass); + loadRegFromStackSlot(MBB, MI, SubReg, FrameIndex + i, + &AMDGPU::SReg_32RegClass, TRI); + BuildMI(MBB, MI, DL, get(AMDGPU::COPY)) + .addReg(DestReg, Flags, RI.getSubRegFromChannel(i)) + .addReg(SubReg); + } + } +} + MachineInstr *SIInstrInfo::commuteInstruction(MachineInstr *MI, bool NewMI) const { diff --git a/lib/Target/R600/SIInstrInfo.h b/lib/Target/R600/SIInstrInfo.h index 4af6348..618deaf 100644 --- a/lib/Target/R600/SIInstrInfo.h +++ b/lib/Target/R600/SIInstrInfo.h @@ -43,6 +43,18 @@ public: unsigned DestReg, unsigned SrcReg, bool KillSrc) const; + void storeRegToStackSlot(MachineBasicBlock &MBB, + MachineBasicBlock::iterator MI, + unsigned SrcReg, bool isKill, int FrameIndex, + const TargetRegisterClass *RC, + const TargetRegisterInfo *TRI) const; + + void loadRegFromStackSlot(MachineBasicBlock &MBB, + MachineBasicBlock::iterator MI, + unsigned DestReg, int FrameIndex, + const TargetRegisterClass *RC, + const TargetRegisterInfo *TRI) const; + unsigned commuteOpcode(unsigned Opcode) const; virtual MachineInstr *commuteInstruction(MachineInstr *MI, diff --git a/lib/Target/R600/SILowerControlFlow.cpp b/lib/Target/R600/SILowerControlFlow.cpp index 958763d..4cac988 100644 --- a/lib/Target/R600/SILowerControlFlow.cpp +++ b/lib/Target/R600/SILowerControlFlow.cpp @@ -431,6 +431,30 @@ bool SILowerControlFlowPass::runOnMachineFunction(MachineFunction &MF) { Next = llvm::next(I); MachineInstr &MI = *I; + +#if 1 + if (MFI->SpillTracker.programSpillsRegisters()) { + // XXX: Register spilling hangs the GPU, so replace the program with a + // dummy shader if we have done any spilling. + if (MI.getOpcode() != AMDGPU::S_ENDPGM) { + MI.eraseFromParent(); + continue; + } + DebugLoc DL = MBB.findDebugLoc(I); + BuildMI(MBB, I, DL, TII->get(AMDGPU::EXP)) + .addImm(0) + .addImm(0x09) // V_008DFC_SQ_EXP_NULL + .addImm(0) + .addImm(1) + .addImm(1) + .addReg(AMDGPU::VGPR0) + .addReg(AMDGPU::VGPR0) + .addReg(AMDGPU::VGPR0) + .addReg(AMDGPU::VGPR0); + continue; + } +#endif + switch (MI.getOpcode()) { default: break; case AMDGPU::SI_IF: diff --git a/lib/Target/R600/SIMachineFunctionInfo.cpp b/lib/Target/R600/SIMachineFunctionInfo.cpp index 071f9fa..525e792 100644 --- a/lib/Target/R600/SIMachineFunctionInfo.cpp +++ b/lib/Target/R600/SIMachineFunctionInfo.cpp @@ -10,6 +10,10 @@ #include "SIMachineFunctionInfo.h" +#include "SIRegisterInfo.h" +#include "llvm/CodeGen/MachineRegisterInfo.h" + +#define MAX_LANES 1 using namespace llvm; @@ -19,4 +23,33 @@ void SIMachineFunctionInfo::anchor() {} SIMachineFunctionInfo::SIMachineFunctionInfo(const MachineFunction &MF) : AMDGPUMachineFunction(MF), - PSInputAddr(0) { } + PSInputAddr(0), + SpillTracker() { } + +static unsigned createLaneVGPR(MachineRegisterInfo &MRI) { + return MRI.createVirtualRegister(&AMDGPU::VReg_32RegClass); +} + +unsigned SIMachineFunctionInfo::RegSpillTracker::getNextLane(MachineRegisterInfo &MRI) { + if (!LaneVGPR) { + LaneVGPR = createLaneVGPR(MRI); + } else { + CurrentLane++; + if (CurrentLane == MAX_LANES) { + CurrentLane = 0; + LaneVGPR = createLaneVGPR(MRI); + } + } + return CurrentLane; +} + +void SIMachineFunctionInfo::RegSpillTracker::addSpilledReg(unsigned FrameIndex, + unsigned Reg, + int Lane) { + SpilledRegisters[FrameIndex] = SpilledReg(Reg, Lane); +} + +const SIMachineFunctionInfo::SpilledReg& +SIMachineFunctionInfo::RegSpillTracker::getSpilledReg(unsigned FrameIndex) { + return SpilledRegisters[FrameIndex]; +} diff --git a/lib/Target/R600/SIMachineFunctionInfo.h b/lib/Target/R600/SIMachineFunctionInfo.h index 2f1961c..8dc82a0 100644 --- a/lib/Target/R600/SIMachineFunctionInfo.h +++ b/lib/Target/R600/SIMachineFunctionInfo.h @@ -16,16 +16,44 @@ #define SIMACHINEFUNCTIONINFO_H_ #include "AMDGPUMachineFunction.h" +#include namespace llvm { +class MachineRegisterInfo; + /// This class keeps track of the SPI_SP_INPUT_ADDR config register, which /// tells the hardware which interpolation parameters to load. class SIMachineFunctionInfo : public AMDGPUMachineFunction { virtual void anchor(); public: + + struct SpilledReg { + unsigned VGPR; + int Lane; + SpilledReg(unsigned R, int L) : VGPR (R), Lane (L) { } + SpilledReg() : VGPR(0), Lane(-1) { } + bool hasLane() { return Lane != -1;} + }; + + struct RegSpillTracker { + private: + unsigned CurrentLane; + std::map SpilledRegisters; + public: + unsigned LaneVGPR; + RegSpillTracker() : CurrentLane(0), SpilledRegisters(), LaneVGPR(0) { } + unsigned getNextLane(MachineRegisterInfo &MRI); + void addSpilledReg(unsigned FrameIndex, unsigned Reg, int Lane = -1); + const SpilledReg& getSpilledReg(unsigned FrameIndex); + bool programSpillsRegisters() { return !SpilledRegisters.empty(); } + }; + + // SIMachineFunctionInfo definition + SIMachineFunctionInfo(const MachineFunction &MF); unsigned PSInputAddr; + struct RegSpillTracker SpillTracker; }; } // End namespace llvm diff --git a/lib/Target/R600/SIRegisterInfo.cpp b/lib/Target/R600/SIRegisterInfo.cpp index ed0bbaf..41784ed 100644 --- a/lib/Target/R600/SIRegisterInfo.cpp +++ b/lib/Target/R600/SIRegisterInfo.cpp @@ -16,6 +16,7 @@ #include "SIRegisterInfo.h" #include "AMDGPUTargetMachine.h" #include "SIInstrInfo.h" +#include "llvm/CodeGen/MachineRegisterInfo.h" using namespace llvm; @@ -129,3 +130,22 @@ const TargetRegisterClass *SIRegisterInfo::getSubRegClass( return &AMDGPU::VGPR_32RegClass; } } + +bool SIRegisterInfo::allUsesCanBeCopiedToVGPR(const MachineRegisterInfo &MRI, + unsigned Reg) const { + if (MRI.use_empty(Reg)) { + return false; + } + const SIInstrInfo *TII = static_cast(TM.getInstrInfo()); + for (MachineRegisterInfo::use_iterator I = MRI.use_begin(Reg), + E = MachineRegisterInfo::use_end(); + I != E; ++I) { + MachineInstr &MI = *I; + if (!TII->canReadVGPR(MI, I.getOperandNo())) { + MI.dump(); + return false; + } + } + return true; +} + diff --git a/lib/Target/R600/SIRegisterInfo.h b/lib/Target/R600/SIRegisterInfo.h index 8148f7f..369c7a0 100644 --- a/lib/Target/R600/SIRegisterInfo.h +++ b/lib/Target/R600/SIRegisterInfo.h @@ -63,6 +63,7 @@ struct SIRegisterInfo : public AMDGPURegisterInfo { /// be returned. const TargetRegisterClass *getSubRegClass(const TargetRegisterClass *RC, unsigned SubIdx) const; + bool allUsesCanBeCopiedToVGPR(const MachineRegisterInfo &MRI, unsigned Reg) const; }; } // End namespace llvm -- 1.8.1.5