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swiftshader/SwiftShader.git/0cd9a67ce/./third_party/llvm-7.0/llvm/lib/Target/AMDGPU/SIRegisterInfo.cpp
blob: 624607f6ea542b412c40fc280a4df730d72d31b3 [file]
//===-- SIRegisterInfo.cpp - SI Register Information ---------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
/// \file
/// SI implementation of the TargetRegisterInfo class.
//
//===----------------------------------------------------------------------===//
#include "SIRegisterInfo.h"
#include "AMDGPURegisterBankInfo.h"
#include "AMDGPUSubtarget.h"
#include "SIInstrInfo.h"
#include "SIMachineFunctionInfo.h"
#include "MCTargetDesc/AMDGPUMCTargetDesc.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/RegisterScavenging.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/LLVMContext.h"
using namespace llvm;
static bool hasPressureSet(const int *PSets, unsigned PSetID) {
for (unsigned i = 0; PSets[i] != -1; ++i) {
if (PSets[i] == (int)PSetID)
return true;
}
return false;
}
void SIRegisterInfo::classifyPressureSet(unsigned PSetID, unsigned Reg,
BitVector &PressureSets) const {
for (MCRegUnitIterator U(Reg, this); U.isValid(); ++U) {
const int *PSets = getRegUnitPressureSets(*U);
if (hasPressureSet(PSets, PSetID)) {
PressureSets.set(PSetID);
break;
}
}
}
static cl::opt<bool> EnableSpillSGPRToSMEM(
"amdgpu-spill-sgpr-to-smem",
cl::desc("Use scalar stores to spill SGPRs if supported by subtarget"),
cl::init(false));
static cl::opt<bool> EnableSpillSGPRToVGPR(
"amdgpu-spill-sgpr-to-vgpr",
cl::desc("Enable spilling VGPRs to SGPRs"),
cl::ReallyHidden,
cl::init(true));
SIRegisterInfo::SIRegisterInfo(const GCNSubtarget &ST) :
AMDGPURegisterInfo(),
SGPRPressureSets(getNumRegPressureSets()),
VGPRPressureSets(getNumRegPressureSets()),
SpillSGPRToVGPR(false),
SpillSGPRToSMEM(false) {
if (EnableSpillSGPRToSMEM && ST.hasScalarStores())
SpillSGPRToSMEM = true;
else if (EnableSpillSGPRToVGPR)
SpillSGPRToVGPR = true;
unsigned NumRegPressureSets = getNumRegPressureSets();
SGPRSetID = NumRegPressureSets;
VGPRSetID = NumRegPressureSets;
for (unsigned i = 0; i < NumRegPressureSets; ++i) {
classifyPressureSet(i, AMDGPU::SGPR0, SGPRPressureSets);
classifyPressureSet(i, AMDGPU::VGPR0, VGPRPressureSets);
}
// Determine the number of reg units for each pressure set.
std::vector<unsigned> PressureSetRegUnits(NumRegPressureSets, 0);
for (unsigned i = 0, e = getNumRegUnits(); i != e; ++i) {
const int *PSets = getRegUnitPressureSets(i);
for (unsigned j = 0; PSets[j] != -1; ++j) {
++PressureSetRegUnits[PSets[j]];
}
}
unsigned VGPRMax = 0, SGPRMax = 0;
for (unsigned i = 0; i < NumRegPressureSets; ++i) {
if (isVGPRPressureSet(i) && PressureSetRegUnits[i] > VGPRMax) {
VGPRSetID = i;
VGPRMax = PressureSetRegUnits[i];
continue;
}
if (isSGPRPressureSet(i) && PressureSetRegUnits[i] > SGPRMax) {
SGPRSetID = i;
SGPRMax = PressureSetRegUnits[i];
}
}
assert(SGPRSetID < NumRegPressureSets &&
VGPRSetID < NumRegPressureSets);
}
unsigned SIRegisterInfo::reservedPrivateSegmentBufferReg(
const MachineFunction &MF) const {
const GCNSubtarget &ST = MF.getSubtarget<GCNSubtarget>();
unsigned BaseIdx = alignDown(ST.getMaxNumSGPRs(MF), 4) - 4;
unsigned BaseReg(AMDGPU::SGPR_32RegClass.getRegister(BaseIdx));
return getMatchingSuperReg(BaseReg, AMDGPU::sub0, &AMDGPU::SReg_128RegClass);
}
static unsigned findPrivateSegmentWaveByteOffsetRegIndex(unsigned RegCount) {
unsigned Reg;
// Try to place it in a hole after PrivateSegmentBufferReg.
if (RegCount & 3) {
// We cannot put the segment buffer in (Idx - 4) ... (Idx - 1) due to
// alignment constraints, so we have a hole where can put the wave offset.
Reg = RegCount - 1;
} else {
// We can put the segment buffer in (Idx - 4) ... (Idx - 1) and put the
// wave offset before it.
Reg = RegCount - 5;
}
return Reg;
}
unsigned SIRegisterInfo::reservedPrivateSegmentWaveByteOffsetReg(
const MachineFunction &MF) const {
const GCNSubtarget &ST = MF.getSubtarget<GCNSubtarget>();
unsigned Reg = findPrivateSegmentWaveByteOffsetRegIndex(ST.getMaxNumSGPRs(MF));
return AMDGPU::SGPR_32RegClass.getRegister(Reg);
}
unsigned SIRegisterInfo::reservedStackPtrOffsetReg(
const MachineFunction &MF) const {
return AMDGPU::SGPR32;
}
BitVector SIRegisterInfo::getReservedRegs(const MachineFunction &MF) const {
BitVector Reserved(getNumRegs());
// EXEC_LO and EXEC_HI could be allocated and used as regular register, but
// this seems likely to result in bugs, so I'm marking them as reserved.
reserveRegisterTuples(Reserved, AMDGPU::EXEC);
reserveRegisterTuples(Reserved, AMDGPU::FLAT_SCR);
// M0 has to be reserved so that llvm accepts it as a live-in into a block.
reserveRegisterTuples(Reserved, AMDGPU::M0);
// Reserve the memory aperture registers.
reserveRegisterTuples(Reserved, AMDGPU::SRC_SHARED_BASE);
reserveRegisterTuples(Reserved, AMDGPU::SRC_SHARED_LIMIT);
reserveRegisterTuples(Reserved, AMDGPU::SRC_PRIVATE_BASE);
reserveRegisterTuples(Reserved, AMDGPU::SRC_PRIVATE_LIMIT);
// Reserve xnack_mask registers - support is not implemented in Codegen.
reserveRegisterTuples(Reserved, AMDGPU::XNACK_MASK);
// Reserve Trap Handler registers - support is not implemented in Codegen.
reserveRegisterTuples(Reserved, AMDGPU::TBA);
reserveRegisterTuples(Reserved, AMDGPU::TMA);
reserveRegisterTuples(Reserved, AMDGPU::TTMP0_TTMP1);
reserveRegisterTuples(Reserved, AMDGPU::TTMP2_TTMP3);
reserveRegisterTuples(Reserved, AMDGPU::TTMP4_TTMP5);
reserveRegisterTuples(Reserved, AMDGPU::TTMP6_TTMP7);
reserveRegisterTuples(Reserved, AMDGPU::TTMP8_TTMP9);
reserveRegisterTuples(Reserved, AMDGPU::TTMP10_TTMP11);
reserveRegisterTuples(Reserved, AMDGPU::TTMP12_TTMP13);
reserveRegisterTuples(Reserved, AMDGPU::TTMP14_TTMP15);
const GCNSubtarget &ST = MF.getSubtarget<GCNSubtarget>();
unsigned MaxNumSGPRs = ST.getMaxNumSGPRs(MF);
unsigned TotalNumSGPRs = AMDGPU::SGPR_32RegClass.getNumRegs();
for (unsigned i = MaxNumSGPRs; i < TotalNumSGPRs; ++i) {
unsigned Reg = AMDGPU::SGPR_32RegClass.getRegister(i);
reserveRegisterTuples(Reserved, Reg);
}
unsigned MaxNumVGPRs = ST.getMaxNumVGPRs(MF);
unsigned TotalNumVGPRs = AMDGPU::VGPR_32RegClass.getNumRegs();
for (unsigned i = MaxNumVGPRs; i < TotalNumVGPRs; ++i) {
unsigned Reg = AMDGPU::VGPR_32RegClass.getRegister(i);
reserveRegisterTuples(Reserved, Reg);
}
const SIMachineFunctionInfo *MFI = MF.getInfo<SIMachineFunctionInfo>();
unsigned ScratchWaveOffsetReg = MFI->getScratchWaveOffsetReg();
if (ScratchWaveOffsetReg != AMDGPU::NoRegister) {
// Reserve 1 SGPR for scratch wave offset in case we need to spill.
reserveRegisterTuples(Reserved, ScratchWaveOffsetReg);
}
unsigned ScratchRSrcReg = MFI->getScratchRSrcReg();
if (ScratchRSrcReg != AMDGPU::NoRegister) {
// Reserve 4 SGPRs for the scratch buffer resource descriptor in case we need
// to spill.
// TODO: May need to reserve a VGPR if doing LDS spilling.
reserveRegisterTuples(Reserved, ScratchRSrcReg);
assert(!isSubRegister(ScratchRSrcReg, ScratchWaveOffsetReg));
}
// We have to assume the SP is needed in case there are calls in the function,
// which is detected after the function is lowered. If we aren't really going
// to need SP, don't bother reserving it.
unsigned StackPtrReg = MFI->getStackPtrOffsetReg();
if (StackPtrReg != AMDGPU::NoRegister) {
reserveRegisterTuples(Reserved, StackPtrReg);
assert(!isSubRegister(ScratchRSrcReg, StackPtrReg));
}
unsigned FrameReg = MFI->getFrameOffsetReg();
if (FrameReg != AMDGPU::NoRegister) {
reserveRegisterTuples(Reserved, FrameReg);
assert(!isSubRegister(ScratchRSrcReg, FrameReg));
}
return Reserved;
}
bool SIRegisterInfo::requiresRegisterScavenging(const MachineFunction &Fn) const {
const SIMachineFunctionInfo *Info = Fn.getInfo<SIMachineFunctionInfo>();
if (Info->isEntryFunction()) {
const MachineFrameInfo &MFI = Fn.getFrameInfo();
return MFI.hasStackObjects() || MFI.hasCalls();
}
// May need scavenger for dealing with callee saved registers.
return true;
}
bool SIRegisterInfo::requiresFrameIndexScavenging(
const MachineFunction &MF) const {
const MachineFrameInfo &MFI = MF.getFrameInfo();
if (MFI.hasStackObjects())
return true;
// May need to deal with callee saved registers.
const SIMachineFunctionInfo *Info = MF.getInfo<SIMachineFunctionInfo>();
return !Info->isEntryFunction();
}
bool SIRegisterInfo::requiresFrameIndexReplacementScavenging(
const MachineFunction &MF) const {
// m0 is needed for the scalar store offset. m0 is unallocatable, so we can't
// create a virtual register for it during frame index elimination, so the
// scavenger is directly needed.
return MF.getFrameInfo().hasStackObjects() &&
MF.getSubtarget<GCNSubtarget>().hasScalarStores() &&
MF.getInfo<SIMachineFunctionInfo>()->hasSpilledSGPRs();
}
bool SIRegisterInfo::requiresVirtualBaseRegisters(
const MachineFunction &) const {
// There are no special dedicated stack or frame pointers.
return true;
}
bool SIRegisterInfo::trackLivenessAfterRegAlloc(const MachineFunction &MF) const {
// This helps catch bugs as verifier errors.
return true;
}
int64_t SIRegisterInfo::getMUBUFInstrOffset(const MachineInstr *MI) const {
assert(SIInstrInfo::isMUBUF(*MI));
int OffIdx = AMDGPU::getNamedOperandIdx(MI->getOpcode(),
AMDGPU::OpName::offset);
return MI->getOperand(OffIdx).getImm();
}
int64_t SIRegisterInfo::getFrameIndexInstrOffset(const MachineInstr *MI,
int Idx) const {
if (!SIInstrInfo::isMUBUF(*MI))
return 0;
assert(Idx == AMDGPU::getNamedOperandIdx(MI->getOpcode(),
AMDGPU::OpName::vaddr) &&
"Should never see frame index on non-address operand");
return getMUBUFInstrOffset(MI);
}
bool SIRegisterInfo::needsFrameBaseReg(MachineInstr *MI, int64_t Offset) const {
if (!MI->mayLoadOrStore())
return false;
int64_t FullOffset = Offset + getMUBUFInstrOffset(MI);
return !isUInt<12>(FullOffset);
}
void SIRegisterInfo::materializeFrameBaseRegister(MachineBasicBlock *MBB,
unsigned BaseReg,
int FrameIdx,
int64_t Offset) const {
MachineBasicBlock::iterator Ins = MBB->begin();
DebugLoc DL; // Defaults to "unknown"
if (Ins != MBB->end())
DL = Ins->getDebugLoc();
MachineFunction *MF = MBB->getParent();
const GCNSubtarget &Subtarget = MF->getSubtarget<GCNSubtarget>();
const SIInstrInfo *TII = Subtarget.getInstrInfo();
if (Offset == 0) {
BuildMI(*MBB, Ins, DL, TII->get(AMDGPU::V_MOV_B32_e32), BaseReg)
.addFrameIndex(FrameIdx);
return;
}
MachineRegisterInfo &MRI = MF->getRegInfo();
unsigned OffsetReg = MRI.createVirtualRegister(&AMDGPU::SReg_32_XM0RegClass);
unsigned FIReg = MRI.createVirtualRegister(&AMDGPU::VGPR_32RegClass);
BuildMI(*MBB, Ins, DL, TII->get(AMDGPU::S_MOV_B32), OffsetReg)
.addImm(Offset);
BuildMI(*MBB, Ins, DL, TII->get(AMDGPU::V_MOV_B32_e32), FIReg)
.addFrameIndex(FrameIdx);
TII->getAddNoCarry(*MBB, Ins, DL, BaseReg)
.addReg(OffsetReg, RegState::Kill)
.addReg(FIReg);
}
void SIRegisterInfo::resolveFrameIndex(MachineInstr &MI, unsigned BaseReg,
int64_t Offset) const {
MachineBasicBlock *MBB = MI.getParent();
MachineFunction *MF = MBB->getParent();
const GCNSubtarget &Subtarget = MF->getSubtarget<GCNSubtarget>();
const SIInstrInfo *TII = Subtarget.getInstrInfo();
#ifndef NDEBUG
// FIXME: Is it possible to be storing a frame index to itself?
bool SeenFI = false;
for (const MachineOperand &MO: MI.operands()) {
if (MO.isFI()) {
if (SeenFI)
llvm_unreachable("should not see multiple frame indices");
SeenFI = true;
}
}
#endif
MachineOperand *FIOp = TII->getNamedOperand(MI, AMDGPU::OpName::vaddr);
assert(FIOp && FIOp->isFI() && "frame index must be address operand");
assert(TII->isMUBUF(MI));
assert(TII->getNamedOperand(MI, AMDGPU::OpName::soffset)->getReg() ==
MF->getInfo<SIMachineFunctionInfo>()->getFrameOffsetReg() &&
"should only be seeing frame offset relative FrameIndex");
MachineOperand *OffsetOp = TII->getNamedOperand(MI, AMDGPU::OpName::offset);
int64_t NewOffset = OffsetOp->getImm() + Offset;
assert(isUInt<12>(NewOffset) && "offset should be legal");
FIOp->ChangeToRegister(BaseReg, false);
OffsetOp->setImm(NewOffset);
}
bool SIRegisterInfo::isFrameOffsetLegal(const MachineInstr *MI,
unsigned BaseReg,
int64_t Offset) const {
if (!SIInstrInfo::isMUBUF(*MI))
return false;
int64_t NewOffset = Offset + getMUBUFInstrOffset(MI);
return isUInt<12>(NewOffset);
}
const TargetRegisterClass *SIRegisterInfo::getPointerRegClass(
const MachineFunction &MF, unsigned Kind) const {
// This is inaccurate. It depends on the instruction and address space. The
// only place where we should hit this is for dealing with frame indexes /
// private accesses, so this is correct in that case.
return &AMDGPU::VGPR_32RegClass;
}
static unsigned getNumSubRegsForSpillOp(unsigned Op) {
switch (Op) {
case AMDGPU::SI_SPILL_S512_SAVE:
case AMDGPU::SI_SPILL_S512_RESTORE:
case AMDGPU::SI_SPILL_V512_SAVE:
case AMDGPU::SI_SPILL_V512_RESTORE:
return 16;
case AMDGPU::SI_SPILL_S256_SAVE:
case AMDGPU::SI_SPILL_S256_RESTORE:
case AMDGPU::SI_SPILL_V256_SAVE:
case AMDGPU::SI_SPILL_V256_RESTORE:
return 8;
case AMDGPU::SI_SPILL_S128_SAVE:
case AMDGPU::SI_SPILL_S128_RESTORE:
case AMDGPU::SI_SPILL_V128_SAVE:
case AMDGPU::SI_SPILL_V128_RESTORE:
return 4;
case AMDGPU::SI_SPILL_V96_SAVE:
case AMDGPU::SI_SPILL_V96_RESTORE:
return 3;
case AMDGPU::SI_SPILL_S64_SAVE:
case AMDGPU::SI_SPILL_S64_RESTORE:
case AMDGPU::SI_SPILL_V64_SAVE:
case AMDGPU::SI_SPILL_V64_RESTORE:
return 2;
case AMDGPU::SI_SPILL_S32_SAVE:
case AMDGPU::SI_SPILL_S32_RESTORE:
case AMDGPU::SI_SPILL_V32_SAVE:
case AMDGPU::SI_SPILL_V32_RESTORE:
return 1;
default: llvm_unreachable("Invalid spill opcode");
}
}
static int getOffsetMUBUFStore(unsigned Opc) {
switch (Opc) {
case AMDGPU::BUFFER_STORE_DWORD_OFFEN:
return AMDGPU::BUFFER_STORE_DWORD_OFFSET;
case AMDGPU::BUFFER_STORE_BYTE_OFFEN:
return AMDGPU::BUFFER_STORE_BYTE_OFFSET;
case AMDGPU::BUFFER_STORE_SHORT_OFFEN:
return AMDGPU::BUFFER_STORE_SHORT_OFFSET;
case AMDGPU::BUFFER_STORE_DWORDX2_OFFEN:
return AMDGPU::BUFFER_STORE_DWORDX2_OFFSET;
case AMDGPU::BUFFER_STORE_DWORDX4_OFFEN:
return AMDGPU::BUFFER_STORE_DWORDX4_OFFSET;
case AMDGPU::BUFFER_STORE_SHORT_D16_HI_OFFEN:
return AMDGPU::BUFFER_STORE_SHORT_D16_HI_OFFSET;
case AMDGPU::BUFFER_STORE_BYTE_D16_HI_OFFEN:
return AMDGPU::BUFFER_STORE_BYTE_D16_HI_OFFSET;
default:
return -1;
}
}
static int getOffsetMUBUFLoad(unsigned Opc) {
switch (Opc) {
case AMDGPU::BUFFER_LOAD_DWORD_OFFEN:
return AMDGPU::BUFFER_LOAD_DWORD_OFFSET;
case AMDGPU::BUFFER_LOAD_UBYTE_OFFEN:
return AMDGPU::BUFFER_LOAD_UBYTE_OFFSET;
case AMDGPU::BUFFER_LOAD_SBYTE_OFFEN:
return AMDGPU::BUFFER_LOAD_SBYTE_OFFSET;
case AMDGPU::BUFFER_LOAD_USHORT_OFFEN:
return AMDGPU::BUFFER_LOAD_USHORT_OFFSET;
case AMDGPU::BUFFER_LOAD_SSHORT_OFFEN:
return AMDGPU::BUFFER_LOAD_SSHORT_OFFSET;
case AMDGPU::BUFFER_LOAD_DWORDX2_OFFEN:
return AMDGPU::BUFFER_LOAD_DWORDX2_OFFSET;
case AMDGPU::BUFFER_LOAD_DWORDX4_OFFEN:
return AMDGPU::BUFFER_LOAD_DWORDX4_OFFSET;
case AMDGPU::BUFFER_LOAD_UBYTE_D16_OFFEN:
return AMDGPU::BUFFER_LOAD_UBYTE_D16_OFFSET;
case AMDGPU::BUFFER_LOAD_UBYTE_D16_HI_OFFEN:
return AMDGPU::BUFFER_LOAD_UBYTE_D16_HI_OFFSET;
case AMDGPU::BUFFER_LOAD_SBYTE_D16_OFFEN:
return AMDGPU::BUFFER_LOAD_SBYTE_D16_OFFSET;
case AMDGPU::BUFFER_LOAD_SBYTE_D16_HI_OFFEN:
return AMDGPU::BUFFER_LOAD_SBYTE_D16_HI_OFFSET;
case AMDGPU::BUFFER_LOAD_SHORT_D16_OFFEN:
return AMDGPU::BUFFER_LOAD_SHORT_D16_OFFSET;
case AMDGPU::BUFFER_LOAD_SHORT_D16_HI_OFFEN:
return AMDGPU::BUFFER_LOAD_SHORT_D16_HI_OFFSET;
default:
return -1;
}
}
// This differs from buildSpillLoadStore by only scavenging a VGPR. It does not
// need to handle the case where an SGPR may need to be spilled while spilling.
static bool buildMUBUFOffsetLoadStore(const SIInstrInfo *TII,
MachineFrameInfo &MFI,
MachineBasicBlock::iterator MI,
int Index,
int64_t Offset) {
MachineBasicBlock *MBB = MI->getParent();
const DebugLoc &DL = MI->getDebugLoc();
bool IsStore = MI->mayStore();
unsigned Opc = MI->getOpcode();
int LoadStoreOp = IsStore ?
getOffsetMUBUFStore(Opc) : getOffsetMUBUFLoad(Opc);
if (LoadStoreOp == -1)
return false;
const MachineOperand *Reg = TII->getNamedOperand(*MI, AMDGPU::OpName::vdata);
MachineInstrBuilder NewMI = BuildMI(*MBB, MI, DL, TII->get(LoadStoreOp))
.add(*Reg)
.add(*TII->getNamedOperand(*MI, AMDGPU::OpName::srsrc))
.add(*TII->getNamedOperand(*MI, AMDGPU::OpName::soffset))
.addImm(Offset)
.addImm(0) // glc
.addImm(0) // slc
.addImm(0) // tfe
.setMemRefs(MI->memoperands_begin(), MI->memoperands_end());
const MachineOperand *VDataIn = TII->getNamedOperand(*MI,
AMDGPU::OpName::vdata_in);
if (VDataIn)
NewMI.add(*VDataIn);
return true;
}
void SIRegisterInfo::buildSpillLoadStore(MachineBasicBlock::iterator MI,
unsigned LoadStoreOp,
int Index,
unsigned ValueReg,
bool IsKill,
unsigned ScratchRsrcReg,
unsigned ScratchOffsetReg,
int64_t InstOffset,
MachineMemOperand *MMO,
RegScavenger *RS) const {
MachineBasicBlock *MBB = MI->getParent();
MachineFunction *MF = MI->getParent()->getParent();
const GCNSubtarget &ST = MF->getSubtarget<GCNSubtarget>();
const SIInstrInfo *TII = ST.getInstrInfo();
const MachineFrameInfo &MFI = MF->getFrameInfo();
const MCInstrDesc &Desc = TII->get(LoadStoreOp);
const DebugLoc &DL = MI->getDebugLoc();
bool IsStore = Desc.mayStore();
bool Scavenged = false;
unsigned SOffset = ScratchOffsetReg;
const unsigned EltSize = 4;
const TargetRegisterClass *RC = getRegClassForReg(MF->getRegInfo(), ValueReg);
unsigned NumSubRegs = AMDGPU::getRegBitWidth(RC->getID()) / (EltSize * CHAR_BIT);
unsigned Size = NumSubRegs * EltSize;
int64_t Offset = InstOffset + MFI.getObjectOffset(Index);
int64_t ScratchOffsetRegDelta = 0;
unsigned Align = MFI.getObjectAlignment(Index);
const MachinePointerInfo &BasePtrInfo = MMO->getPointerInfo();
assert((Offset % EltSize) == 0 && "unexpected VGPR spill offset");
if (!isUInt<12>(Offset + Size - EltSize)) {
SOffset = AMDGPU::NoRegister;
// We currently only support spilling VGPRs to EltSize boundaries, meaning
// we can simplify the adjustment of Offset here to just scale with
// WavefrontSize.
Offset *= ST.getWavefrontSize();
// We don't have access to the register scavenger if this function is called
// during PEI::scavengeFrameVirtualRegs().
if (RS)
SOffset = RS->FindUnusedReg(&AMDGPU::SGPR_32RegClass);
if (SOffset == AMDGPU::NoRegister) {
// There are no free SGPRs, and since we are in the process of spilling
// VGPRs too. Since we need a VGPR in order to spill SGPRs (this is true
// on SI/CI and on VI it is true until we implement spilling using scalar
// stores), we have no way to free up an SGPR. Our solution here is to
// add the offset directly to the ScratchOffset register, and then
// subtract the offset after the spill to return ScratchOffset to it's
// original value.
SOffset = ScratchOffsetReg;
ScratchOffsetRegDelta = Offset;
} else {
Scavenged = true;
}
BuildMI(*MBB, MI, DL, TII->get(AMDGPU::S_ADD_U32), SOffset)
.addReg(ScratchOffsetReg)
.addImm(Offset);
Offset = 0;
}
for (unsigned i = 0, e = NumSubRegs; i != e; ++i, Offset += EltSize) {
unsigned SubReg = NumSubRegs == 1 ?
ValueReg : getSubReg(ValueReg, getSubRegFromChannel(i));
unsigned SOffsetRegState = 0;
unsigned SrcDstRegState = getDefRegState(!IsStore);
if (i + 1 == e) {
SOffsetRegState |= getKillRegState(Scavenged);
// The last implicit use carries the "Kill" flag.
SrcDstRegState |= getKillRegState(IsKill);
}
MachinePointerInfo PInfo = BasePtrInfo.getWithOffset(EltSize * i);
MachineMemOperand *NewMMO
= MF->getMachineMemOperand(PInfo, MMO->getFlags(),
EltSize, MinAlign(Align, EltSize * i));
auto MIB = BuildMI(*MBB, MI, DL, Desc)
.addReg(SubReg, getDefRegState(!IsStore) | getKillRegState(IsKill))
.addReg(ScratchRsrcReg)
.addReg(SOffset, SOffsetRegState)
.addImm(Offset)
.addImm(0) // glc
.addImm(0) // slc
.addImm(0) // tfe
.addMemOperand(NewMMO);
if (NumSubRegs > 1)
MIB.addReg(ValueReg, RegState::Implicit | SrcDstRegState);
}
if (ScratchOffsetRegDelta != 0) {
// Subtract the offset we added to the ScratchOffset register.
BuildMI(*MBB, MI, DL, TII->get(AMDGPU::S_SUB_U32), ScratchOffsetReg)
.addReg(ScratchOffsetReg)
.addImm(ScratchOffsetRegDelta);
}
}
static std::pair<unsigned, unsigned> getSpillEltSize(unsigned SuperRegSize,
bool Store) {
if (SuperRegSize % 16 == 0) {
return { 16, Store ? AMDGPU::S_BUFFER_STORE_DWORDX4_SGPR :
AMDGPU::S_BUFFER_LOAD_DWORDX4_SGPR };
}
if (SuperRegSize % 8 == 0) {
return { 8, Store ? AMDGPU::S_BUFFER_STORE_DWORDX2_SGPR :
AMDGPU::S_BUFFER_LOAD_DWORDX2_SGPR };
}
return { 4, Store ? AMDGPU::S_BUFFER_STORE_DWORD_SGPR :
AMDGPU::S_BUFFER_LOAD_DWORD_SGPR};
}
bool SIRegisterInfo::spillSGPR(MachineBasicBlock::iterator MI,
int Index,
RegScavenger *RS,
bool OnlyToVGPR) const {
MachineBasicBlock *MBB = MI->getParent();
MachineFunction *MF = MBB->getParent();
SIMachineFunctionInfo *MFI = MF->getInfo<SIMachineFunctionInfo>();
DenseSet<unsigned> SGPRSpillVGPRDefinedSet;
ArrayRef<SIMachineFunctionInfo::SpilledReg> VGPRSpills
= MFI->getSGPRToVGPRSpills(Index);
bool SpillToVGPR = !VGPRSpills.empty();
if (OnlyToVGPR && !SpillToVGPR)
return false;
MachineRegisterInfo &MRI = MF->getRegInfo();
const GCNSubtarget &ST = MF->getSubtarget<GCNSubtarget>();
const SIInstrInfo *TII = ST.getInstrInfo();
unsigned SuperReg = MI->getOperand(0).getReg();
bool IsKill = MI->getOperand(0).isKill();
const DebugLoc &DL = MI->getDebugLoc();
MachineFrameInfo &FrameInfo = MF->getFrameInfo();
bool SpillToSMEM = spillSGPRToSMEM();
if (SpillToSMEM && OnlyToVGPR)
return false;
assert(SpillToVGPR || (SuperReg != MFI->getStackPtrOffsetReg() &&
SuperReg != MFI->getFrameOffsetReg() &&
SuperReg != MFI->getScratchWaveOffsetReg()));
assert(SuperReg != AMDGPU::M0 && "m0 should never spill");
unsigned OffsetReg = AMDGPU::M0;
unsigned M0CopyReg = AMDGPU::NoRegister;
if (SpillToSMEM) {
if (RS->isRegUsed(AMDGPU::M0)) {
M0CopyReg = MRI.createVirtualRegister(&AMDGPU::SReg_32_XM0RegClass);
BuildMI(*MBB, MI, DL, TII->get(AMDGPU::COPY), M0CopyReg)
.addReg(AMDGPU::M0);
}
}
unsigned ScalarStoreOp;
unsigned EltSize = 4;
const TargetRegisterClass *RC = getPhysRegClass(SuperReg);
if (SpillToSMEM && isSGPRClass(RC)) {
// XXX - if private_element_size is larger than 4 it might be useful to be
// able to spill wider vmem spills.
std::tie(EltSize, ScalarStoreOp) =
getSpillEltSize(getRegSizeInBits(*RC) / 8, true);
}
ArrayRef<int16_t> SplitParts = getRegSplitParts(RC, EltSize);
unsigned NumSubRegs = SplitParts.empty() ? 1 : SplitParts.size();
// SubReg carries the "Kill" flag when SubReg == SuperReg.
unsigned SubKillState = getKillRegState((NumSubRegs == 1) && IsKill);
for (unsigned i = 0, e = NumSubRegs; i < e; ++i) {
unsigned SubReg = NumSubRegs == 1 ?
SuperReg : getSubReg(SuperReg, SplitParts[i]);
if (SpillToSMEM) {
int64_t FrOffset = FrameInfo.getObjectOffset(Index);
// The allocated memory size is really the wavefront size * the frame
// index size. The widest register class is 64 bytes, so a 4-byte scratch
// allocation is enough to spill this in a single stack object.
//
// FIXME: Frame size/offsets are computed earlier than this, so the extra
// space is still unnecessarily allocated.
unsigned Align = FrameInfo.getObjectAlignment(Index);
MachinePointerInfo PtrInfo
= MachinePointerInfo::getFixedStack(*MF, Index, EltSize * i);
MachineMemOperand *MMO
= MF->getMachineMemOperand(PtrInfo, MachineMemOperand::MOStore,
EltSize, MinAlign(Align, EltSize * i));
// SMEM instructions only support a single offset, so increment the wave
// offset.
int64_t Offset = (ST.getWavefrontSize() * FrOffset) + (EltSize * i);
if (Offset != 0) {
BuildMI(*MBB, MI, DL, TII->get(AMDGPU::S_ADD_U32), OffsetReg)
.addReg(MFI->getFrameOffsetReg())
.addImm(Offset);
} else {
BuildMI(*MBB, MI, DL, TII->get(AMDGPU::S_MOV_B32), OffsetReg)
.addReg(MFI->getFrameOffsetReg());
}
BuildMI(*MBB, MI, DL, TII->get(ScalarStoreOp))
.addReg(SubReg, getKillRegState(IsKill)) // sdata
.addReg(MFI->getScratchRSrcReg()) // sbase
.addReg(OffsetReg, RegState::Kill) // soff
.addImm(0) // glc
.addMemOperand(MMO);
continue;
}
if (SpillToVGPR) {
SIMachineFunctionInfo::SpilledReg Spill = VGPRSpills[i];
// During SGPR spilling to VGPR, determine if the VGPR is defined. The
// only circumstance in which we say it is undefined is when it is the
// first spill to this VGPR in the first basic block.
bool VGPRDefined = true;
if (MBB == &MF->front())
VGPRDefined = !SGPRSpillVGPRDefinedSet.insert(Spill.VGPR).second;
// Mark the "old value of vgpr" input undef only if this is the first sgpr
// spill to this specific vgpr in the first basic block.
BuildMI(*MBB, MI, DL,
TII->getMCOpcodeFromPseudo(AMDGPU::V_WRITELANE_B32),
Spill.VGPR)
.addReg(SubReg, getKillRegState(IsKill))
.addImm(Spill.Lane)
.addReg(Spill.VGPR, VGPRDefined ? 0 : RegState::Undef);
// FIXME: Since this spills to another register instead of an actual
// frame index, we should delete the frame index when all references to
// it are fixed.
} else {
// XXX - Can to VGPR spill fail for some subregisters but not others?
if (OnlyToVGPR)
return false;
// Spill SGPR to a frame index.
// TODO: Should VI try to spill to VGPR and then spill to SMEM?
unsigned TmpReg = MRI.createVirtualRegister(&AMDGPU::VGPR_32RegClass);
// TODO: Should VI try to spill to VGPR and then spill to SMEM?
MachineInstrBuilder Mov
= BuildMI(*MBB, MI, DL, TII->get(AMDGPU::V_MOV_B32_e32), TmpReg)
.addReg(SubReg, SubKillState);
// There could be undef components of a spilled super register.
// TODO: Can we detect this and skip the spill?
if (NumSubRegs > 1) {
// The last implicit use of the SuperReg carries the "Kill" flag.
unsigned SuperKillState = 0;
if (i + 1 == e)
SuperKillState |= getKillRegState(IsKill);
Mov.addReg(SuperReg, RegState::Implicit | SuperKillState);
}
unsigned Align = FrameInfo.getObjectAlignment(Index);
MachinePointerInfo PtrInfo
= MachinePointerInfo::getFixedStack(*MF, Index, EltSize * i);
MachineMemOperand *MMO
= MF->getMachineMemOperand(PtrInfo, MachineMemOperand::MOStore,
EltSize, MinAlign(Align, EltSize * i));
BuildMI(*MBB, MI, DL, TII->get(AMDGPU::SI_SPILL_V32_SAVE))
.addReg(TmpReg, RegState::Kill) // src
.addFrameIndex(Index) // vaddr
.addReg(MFI->getScratchRSrcReg()) // srrsrc
.addReg(MFI->getFrameOffsetReg()) // soffset
.addImm(i * 4) // offset
.addMemOperand(MMO);
}
}
if (M0CopyReg != AMDGPU::NoRegister) {
BuildMI(*MBB, MI, DL, TII->get(AMDGPU::COPY), AMDGPU::M0)
.addReg(M0CopyReg, RegState::Kill);
}
MI->eraseFromParent();
MFI->addToSpilledSGPRs(NumSubRegs);
return true;
}
bool SIRegisterInfo::restoreSGPR(MachineBasicBlock::iterator MI,
int Index,
RegScavenger *RS,
bool OnlyToVGPR) const {
MachineFunction *MF = MI->getParent()->getParent();
MachineRegisterInfo &MRI = MF->getRegInfo();
MachineBasicBlock *MBB = MI->getParent();
SIMachineFunctionInfo *MFI = MF->getInfo<SIMachineFunctionInfo>();
ArrayRef<SIMachineFunctionInfo::SpilledReg> VGPRSpills
= MFI->getSGPRToVGPRSpills(Index);
bool SpillToVGPR = !VGPRSpills.empty();
if (OnlyToVGPR && !SpillToVGPR)
return false;
MachineFrameInfo &FrameInfo = MF->getFrameInfo();
const GCNSubtarget &ST = MF->getSubtarget<GCNSubtarget>();
const SIInstrInfo *TII = ST.getInstrInfo();
const DebugLoc &DL = MI->getDebugLoc();
unsigned SuperReg = MI->getOperand(0).getReg();
bool SpillToSMEM = spillSGPRToSMEM();
if (SpillToSMEM && OnlyToVGPR)
return false;
assert(SuperReg != AMDGPU::M0 && "m0 should never spill");
unsigned OffsetReg = AMDGPU::M0;
unsigned M0CopyReg = AMDGPU::NoRegister;
if (SpillToSMEM) {
if (RS->isRegUsed(AMDGPU::M0)) {
M0CopyReg = MRI.createVirtualRegister(&AMDGPU::SReg_32_XM0RegClass);
BuildMI(*MBB, MI, DL, TII->get(AMDGPU::COPY), M0CopyReg)
.addReg(AMDGPU::M0);
}
}
unsigned EltSize = 4;
unsigned ScalarLoadOp;
const TargetRegisterClass *RC = getPhysRegClass(SuperReg);
if (SpillToSMEM && isSGPRClass(RC)) {
// XXX - if private_element_size is larger than 4 it might be useful to be
// able to spill wider vmem spills.
std::tie(EltSize, ScalarLoadOp) =
getSpillEltSize(getRegSizeInBits(*RC) / 8, false);
}
ArrayRef<int16_t> SplitParts = getRegSplitParts(RC, EltSize);
unsigned NumSubRegs = SplitParts.empty() ? 1 : SplitParts.size();
// SubReg carries the "Kill" flag when SubReg == SuperReg.
int64_t FrOffset = FrameInfo.getObjectOffset(Index);
for (unsigned i = 0, e = NumSubRegs; i < e; ++i) {
unsigned SubReg = NumSubRegs == 1 ?
SuperReg : getSubReg(SuperReg, SplitParts[i]);
if (SpillToSMEM) {
// FIXME: Size may be > 4 but extra bytes wasted.
unsigned Align = FrameInfo.getObjectAlignment(Index);
MachinePointerInfo PtrInfo
= MachinePointerInfo::getFixedStack(*MF, Index, EltSize * i);
MachineMemOperand *MMO
= MF->getMachineMemOperand(PtrInfo, MachineMemOperand::MOLoad,
EltSize, MinAlign(Align, EltSize * i));
// Add i * 4 offset
int64_t Offset = (ST.getWavefrontSize() * FrOffset) + (EltSize * i);
if (Offset != 0) {
BuildMI(*MBB, MI, DL, TII->get(AMDGPU::S_ADD_U32), OffsetReg)
.addReg(MFI->getFrameOffsetReg())
.addImm(Offset);
} else {
BuildMI(*MBB, MI, DL, TII->get(AMDGPU::S_MOV_B32), OffsetReg)
.addReg(MFI->getFrameOffsetReg());
}
auto MIB =
BuildMI(*MBB, MI, DL, TII->get(ScalarLoadOp), SubReg)
.addReg(MFI->getScratchRSrcReg()) // sbase
.addReg(OffsetReg, RegState::Kill) // soff
.addImm(0) // glc
.addMemOperand(MMO);
if (NumSubRegs > 1)
MIB.addReg(SuperReg, RegState::ImplicitDefine);
continue;
}
if (SpillToVGPR) {
SIMachineFunctionInfo::SpilledReg Spill = VGPRSpills[i];
auto MIB =
BuildMI(*MBB, MI, DL, TII->getMCOpcodeFromPseudo(AMDGPU::V_READLANE_B32),
SubReg)
.addReg(Spill.VGPR)
.addImm(Spill.Lane);
if (NumSubRegs > 1)
MIB.addReg(SuperReg, RegState::ImplicitDefine);
} else {
if (OnlyToVGPR)
return false;
// Restore SGPR from a stack slot.
// FIXME: We should use S_LOAD_DWORD here for VI.
unsigned TmpReg = MRI.createVirtualRegister(&AMDGPU::VGPR_32RegClass);
unsigned Align = FrameInfo.getObjectAlignment(Index);
MachinePointerInfo PtrInfo
= MachinePointerInfo::getFixedStack(*MF, Index, EltSize * i);
MachineMemOperand *MMO = MF->getMachineMemOperand(PtrInfo,
MachineMemOperand::MOLoad, EltSize,
MinAlign(Align, EltSize * i));
BuildMI(*MBB, MI, DL, TII->get(AMDGPU::SI_SPILL_V32_RESTORE), TmpReg)
.addFrameIndex(Index) // vaddr
.addReg(MFI->getScratchRSrcReg()) // srsrc
.addReg(MFI->getFrameOffsetReg()) // soffset
.addImm(i * 4) // offset
.addMemOperand(MMO);
auto MIB =
BuildMI(*MBB, MI, DL, TII->get(AMDGPU::V_READFIRSTLANE_B32), SubReg)
.addReg(TmpReg, RegState::Kill);
if (NumSubRegs > 1)
MIB.addReg(MI->getOperand(0).getReg(), RegState::ImplicitDefine);
}
}
if (M0CopyReg != AMDGPU::NoRegister) {
BuildMI(*MBB, MI, DL, TII->get(AMDGPU::COPY), AMDGPU::M0)
.addReg(M0CopyReg, RegState::Kill);
}
MI->eraseFromParent();
return true;
}
/// Special case of eliminateFrameIndex. Returns true if the SGPR was spilled to
/// a VGPR and the stack slot can be safely eliminated when all other users are
/// handled.
bool SIRegisterInfo::eliminateSGPRToVGPRSpillFrameIndex(
MachineBasicBlock::iterator MI,
int FI,
RegScavenger *RS) const {
switch (MI->getOpcode()) {
case AMDGPU::SI_SPILL_S512_SAVE:
case AMDGPU::SI_SPILL_S256_SAVE:
case AMDGPU::SI_SPILL_S128_SAVE:
case AMDGPU::SI_SPILL_S64_SAVE:
case AMDGPU::SI_SPILL_S32_SAVE:
return spillSGPR(MI, FI, RS, true);
case AMDGPU::SI_SPILL_S512_RESTORE:
case AMDGPU::SI_SPILL_S256_RESTORE:
case AMDGPU::SI_SPILL_S128_RESTORE:
case AMDGPU::SI_SPILL_S64_RESTORE:
case AMDGPU::SI_SPILL_S32_RESTORE:
return restoreSGPR(MI, FI, RS, true);
default:
llvm_unreachable("not an SGPR spill instruction");
}
}
void SIRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator MI,
int SPAdj, unsigned FIOperandNum,
RegScavenger *RS) const {
MachineFunction *MF = MI->getParent()->getParent();
MachineRegisterInfo &MRI = MF->getRegInfo();
MachineBasicBlock *MBB = MI->getParent();
SIMachineFunctionInfo *MFI = MF->getInfo<SIMachineFunctionInfo>();
MachineFrameInfo &FrameInfo = MF->getFrameInfo();
const GCNSubtarget &ST = MF->getSubtarget<GCNSubtarget>();
const SIInstrInfo *TII = ST.getInstrInfo();
DebugLoc DL = MI->getDebugLoc();
MachineOperand &FIOp = MI->getOperand(FIOperandNum);
int Index = MI->getOperand(FIOperandNum).getIndex();
switch (MI->getOpcode()) {
// SGPR register spill
case AMDGPU::SI_SPILL_S512_SAVE:
case AMDGPU::SI_SPILL_S256_SAVE:
case AMDGPU::SI_SPILL_S128_SAVE:
case AMDGPU::SI_SPILL_S64_SAVE:
case AMDGPU::SI_SPILL_S32_SAVE: {
spillSGPR(MI, Index, RS);
break;
}
// SGPR register restore
case AMDGPU::SI_SPILL_S512_RESTORE:
case AMDGPU::SI_SPILL_S256_RESTORE:
case AMDGPU::SI_SPILL_S128_RESTORE:
case AMDGPU::SI_SPILL_S64_RESTORE:
case AMDGPU::SI_SPILL_S32_RESTORE: {
restoreSGPR(MI, Index, RS);
break;
}
// VGPR register spill
case AMDGPU::SI_SPILL_V512_SAVE:
case AMDGPU::SI_SPILL_V256_SAVE:
case AMDGPU::SI_SPILL_V128_SAVE:
case AMDGPU::SI_SPILL_V96_SAVE:
case AMDGPU::SI_SPILL_V64_SAVE:
case AMDGPU::SI_SPILL_V32_SAVE: {
const MachineOperand *VData = TII->getNamedOperand(*MI,
AMDGPU::OpName::vdata);
buildSpillLoadStore(MI, AMDGPU::BUFFER_STORE_DWORD_OFFSET,
Index,
VData->getReg(), VData->isKill(),
TII->getNamedOperand(*MI, AMDGPU::OpName::srsrc)->getReg(),
TII->getNamedOperand(*MI, AMDGPU::OpName::soffset)->getReg(),
TII->getNamedOperand(*MI, AMDGPU::OpName::offset)->getImm(),
*MI->memoperands_begin(),
RS);
MFI->addToSpilledVGPRs(getNumSubRegsForSpillOp(MI->getOpcode()));
MI->eraseFromParent();
break;
}
case AMDGPU::SI_SPILL_V32_RESTORE:
case AMDGPU::SI_SPILL_V64_RESTORE:
case AMDGPU::SI_SPILL_V96_RESTORE:
case AMDGPU::SI_SPILL_V128_RESTORE:
case AMDGPU::SI_SPILL_V256_RESTORE:
case AMDGPU::SI_SPILL_V512_RESTORE: {
const MachineOperand *VData = TII->getNamedOperand(*MI,
AMDGPU::OpName::vdata);
buildSpillLoadStore(MI, AMDGPU::BUFFER_LOAD_DWORD_OFFSET,
Index,
VData->getReg(), VData->isKill(),
TII->getNamedOperand(*MI, AMDGPU::OpName::srsrc)->getReg(),
TII->getNamedOperand(*MI, AMDGPU::OpName::soffset)->getReg(),
TII->getNamedOperand(*MI, AMDGPU::OpName::offset)->getImm(),
*MI->memoperands_begin(),
RS);
MI->eraseFromParent();
break;
}
default: {
const DebugLoc &DL = MI->getDebugLoc();
bool IsMUBUF = TII->isMUBUF(*MI);
if (!IsMUBUF &&
MFI->getFrameOffsetReg() != MFI->getScratchWaveOffsetReg()) {
// Convert to an absolute stack address by finding the offset from the
// scratch wave base and scaling by the wave size.
//
// In an entry function/kernel the stack address is already the
// absolute address relative to the scratch wave offset.
unsigned DiffReg
= MRI.createVirtualRegister(&AMDGPU::SReg_32_XM0RegClass);
bool IsCopy = MI->getOpcode() == AMDGPU::V_MOV_B32_e32;
unsigned ResultReg = IsCopy ?
MI->getOperand(0).getReg() :
MRI.createVirtualRegister(&AMDGPU::VGPR_32RegClass);
BuildMI(*MBB, MI, DL, TII->get(AMDGPU::S_SUB_U32), DiffReg)
.addReg(MFI->getFrameOffsetReg())
.addReg(MFI->getScratchWaveOffsetReg());
int64_t Offset = FrameInfo.getObjectOffset(Index);
if (Offset == 0) {
// XXX - This never happens because of emergency scavenging slot at 0?
BuildMI(*MBB, MI, DL, TII->get(AMDGPU::V_LSHRREV_B32_e64), ResultReg)
.addImm(Log2_32(ST.getWavefrontSize()))
.addReg(DiffReg);
} else {
unsigned ScaledReg
= MRI.createVirtualRegister(&AMDGPU::VGPR_32RegClass);
BuildMI(*MBB, MI, DL, TII->get(AMDGPU::V_LSHRREV_B32_e64), ScaledReg)
.addImm(Log2_32(ST.getWavefrontSize()))
.addReg(DiffReg, RegState::Kill);
// TODO: Fold if use instruction is another add of a constant.
if (AMDGPU::isInlinableLiteral32(Offset, ST.hasInv2PiInlineImm())) {
TII->getAddNoCarry(*MBB, MI, DL, ResultReg)
.addImm(Offset)
.addReg(ScaledReg, RegState::Kill);
} else {
unsigned ConstOffsetReg
= MRI.createVirtualRegister(&AMDGPU::SReg_32_XM0RegClass);
BuildMI(*MBB, MI, DL, TII->get(AMDGPU::S_MOV_B32), ConstOffsetReg)
.addImm(Offset);
TII->getAddNoCarry(*MBB, MI, DL, ResultReg)
.addReg(ConstOffsetReg, RegState::Kill)
.addReg(ScaledReg, RegState::Kill);
}
}
// Don't introduce an extra copy if we're just materializing in a mov.
if (IsCopy)
MI->eraseFromParent();
else
FIOp.ChangeToRegister(ResultReg, false, false, true);
return;
}
if (IsMUBUF) {
// Disable offen so we don't need a 0 vgpr base.
assert(static_cast<int>(FIOperandNum) ==
AMDGPU::getNamedOperandIdx(MI->getOpcode(),
AMDGPU::OpName::vaddr));
assert(TII->getNamedOperand(*MI, AMDGPU::OpName::soffset)->getReg()
== MFI->getFrameOffsetReg());
int64_t Offset = FrameInfo.getObjectOffset(Index);
int64_t OldImm
= TII->getNamedOperand(*MI, AMDGPU::OpName::offset)->getImm();
int64_t NewOffset = OldImm + Offset;
if (isUInt<12>(NewOffset) &&
buildMUBUFOffsetLoadStore(TII, FrameInfo, MI, Index, NewOffset)) {
MI->eraseFromParent();
return;
}
}
// If the offset is simply too big, don't convert to a scratch wave offset
// relative index.
int64_t Offset = FrameInfo.getObjectOffset(Index);
FIOp.ChangeToImmediate(Offset);
if (!TII->isImmOperandLegal(*MI, FIOperandNum, FIOp)) {
unsigned TmpReg = MRI.createVirtualRegister(&AMDGPU::VGPR_32RegClass);
BuildMI(*MBB, MI, DL, TII->get(AMDGPU::V_MOV_B32_e32), TmpReg)
.addImm(Offset);
FIOp.ChangeToRegister(TmpReg, false, false, true);
}
}
}
}
StringRef SIRegisterInfo::getRegAsmName(unsigned Reg) const {
#define AMDGPU_REG_ASM_NAMES
#include "AMDGPURegAsmNames.inc.cpp"
#define REG_RANGE(BeginReg, EndReg, RegTable) \
if (Reg >= BeginReg && Reg <= EndReg) { \
unsigned Index = Reg - BeginReg; \
assert(Index < array_lengthof(RegTable)); \
return RegTable[Index]; \
}
REG_RANGE(AMDGPU::VGPR0, AMDGPU::VGPR255, VGPR32RegNames);
REG_RANGE(AMDGPU::SGPR0, AMDGPU::SGPR103, SGPR32RegNames);
REG_RANGE(AMDGPU::VGPR0_VGPR1, AMDGPU::VGPR254_VGPR255, VGPR64RegNames);
REG_RANGE(AMDGPU::SGPR0_SGPR1, AMDGPU::SGPR102_SGPR103, SGPR64RegNames);
REG_RANGE(AMDGPU::VGPR0_VGPR1_VGPR2, AMDGPU::VGPR253_VGPR254_VGPR255,
VGPR96RegNames);
REG_RANGE(AMDGPU::VGPR0_VGPR1_VGPR2_VGPR3,
AMDGPU::VGPR252_VGPR253_VGPR254_VGPR255,
VGPR128RegNames);
REG_RANGE(AMDGPU::SGPR0_SGPR1_SGPR2_SGPR3,
AMDGPU::SGPR100_SGPR101_SGPR102_SGPR103,
SGPR128RegNames);
REG_RANGE(AMDGPU::VGPR0_VGPR1_VGPR2_VGPR3_VGPR4_VGPR5_VGPR6_VGPR7,
AMDGPU::VGPR248_VGPR249_VGPR250_VGPR251_VGPR252_VGPR253_VGPR254_VGPR255,
VGPR256RegNames);
REG_RANGE(
AMDGPU::VGPR0_VGPR1_VGPR2_VGPR3_VGPR4_VGPR5_VGPR6_VGPR7_VGPR8_VGPR9_VGPR10_VGPR11_VGPR12_VGPR13_VGPR14_VGPR15,
AMDGPU::VGPR240_VGPR241_VGPR242_VGPR243_VGPR244_VGPR245_VGPR246_VGPR247_VGPR248_VGPR249_VGPR250_VGPR251_VGPR252_VGPR253_VGPR254_VGPR255,
VGPR512RegNames);
REG_RANGE(AMDGPU::SGPR0_SGPR1_SGPR2_SGPR3_SGPR4_SGPR5_SGPR6_SGPR7,
AMDGPU::SGPR96_SGPR97_SGPR98_SGPR99_SGPR100_SGPR101_SGPR102_SGPR103,
SGPR256RegNames);
REG_RANGE(
AMDGPU::SGPR0_SGPR1_SGPR2_SGPR3_SGPR4_SGPR5_SGPR6_SGPR7_SGPR8_SGPR9_SGPR10_SGPR11_SGPR12_SGPR13_SGPR14_SGPR15,
AMDGPU::SGPR88_SGPR89_SGPR90_SGPR91_SGPR92_SGPR93_SGPR94_SGPR95_SGPR96_SGPR97_SGPR98_SGPR99_SGPR100_SGPR101_SGPR102_SGPR103,
SGPR512RegNames
);
#undef REG_RANGE
// FIXME: Rename flat_scr so we don't need to special case this.
switch (Reg) {
case AMDGPU::FLAT_SCR:
return "flat_scratch";
case AMDGPU::FLAT_SCR_LO:
return "flat_scratch_lo";
case AMDGPU::FLAT_SCR_HI:
return "flat_scratch_hi";
default:
// For the special named registers the default is fine.
return TargetRegisterInfo::getRegAsmName(Reg);
}
}
// FIXME: This is very slow. It might be worth creating a map from physreg to
// register class.
const TargetRegisterClass *SIRegisterInfo::getPhysRegClass(unsigned Reg) const {
assert(!TargetRegisterInfo::isVirtualRegister(Reg));
static const TargetRegisterClass *const BaseClasses[] = {
&AMDGPU::VGPR_32RegClass,
&AMDGPU::SReg_32RegClass,
&AMDGPU::VReg_64RegClass,
&AMDGPU::SReg_64RegClass,
&AMDGPU::VReg_96RegClass,
&AMDGPU::VReg_128RegClass,
&AMDGPU::SReg_128RegClass,
&AMDGPU::VReg_256RegClass,
&AMDGPU::SReg_256RegClass,
&AMDGPU::VReg_512RegClass,
&AMDGPU::SReg_512RegClass,
&AMDGPU::SCC_CLASSRegClass,
&AMDGPU::Pseudo_SReg_32RegClass,
&AMDGPU::Pseudo_SReg_128RegClass,
};
for (const TargetRegisterClass *BaseClass : BaseClasses) {
if (BaseClass->contains(Reg)) {
return BaseClass;
}
}
return nullptr;
}
// TODO: It might be helpful to have some target specific flags in
// TargetRegisterClass to mark which classes are VGPRs to make this trivial.
bool SIRegisterInfo::hasVGPRs(const TargetRegisterClass *RC) const {
unsigned Size = getRegSizeInBits(*RC);
if (Size < 32)
return false;
switch (Size) {
case 32:
return getCommonSubClass(&AMDGPU::VGPR_32RegClass, RC) != nullptr;
case 64:
return getCommonSubClass(&AMDGPU::VReg_64RegClass, RC) != nullptr;
case 96:
return getCommonSubClass(&AMDGPU::VReg_96RegClass, RC) != nullptr;
case 128:
return getCommonSubClass(&AMDGPU::VReg_128RegClass, RC) != nullptr;
case 256:
return getCommonSubClass(&AMDGPU::VReg_256RegClass, RC) != nullptr;
case 512:
return getCommonSubClass(&AMDGPU::VReg_512RegClass, RC) != nullptr;
default:
llvm_unreachable("Invalid register class size");
}
}
const TargetRegisterClass *SIRegisterInfo::getEquivalentVGPRClass(
const TargetRegisterClass *SRC) const {
switch (getRegSizeInBits(*SRC)) {
case 32:
return &AMDGPU::VGPR_32RegClass;
case 64:
return &AMDGPU::VReg_64RegClass;
case 96:
return &AMDGPU::VReg_96RegClass;
case 128:
return &AMDGPU::VReg_128RegClass;
case 256:
return &AMDGPU::VReg_256RegClass;
case 512:
return &AMDGPU::VReg_512RegClass;
default:
llvm_unreachable("Invalid register class size");
}
}
const TargetRegisterClass *SIRegisterInfo::getEquivalentSGPRClass(
const TargetRegisterClass *VRC) const {
switch (getRegSizeInBits(*VRC)) {
case 32:
return &AMDGPU::SGPR_32RegClass;
case 64:
return &AMDGPU::SReg_64RegClass;
case 128:
return &AMDGPU::SReg_128RegClass;
case 256:
return &AMDGPU::SReg_256RegClass;
case 512:
return &AMDGPU::SReg_512RegClass;
default:
llvm_unreachable("Invalid register class size");
}
}
const TargetRegisterClass *SIRegisterInfo::getSubRegClass(
const TargetRegisterClass *RC, unsigned SubIdx) const {
if (SubIdx == AMDGPU::NoSubRegister)
return RC;
// We can assume that each lane corresponds to one 32-bit register.
unsigned Count = getSubRegIndexLaneMask(SubIdx).getNumLanes();
if (isSGPRClass(RC)) {
switch (Count) {
case 1:
return &AMDGPU::SGPR_32RegClass;
case 2:
return &AMDGPU::SReg_64RegClass;
case 4:
return &AMDGPU::SReg_128RegClass;
case 8:
return &AMDGPU::SReg_256RegClass;
case 16: /* fall-through */
default:
llvm_unreachable("Invalid sub-register class size");
}
} else {
switch (Count) {
case 1:
return &AMDGPU::VGPR_32RegClass;
case 2:
return &AMDGPU::VReg_64RegClass;
case 3:
return &AMDGPU::VReg_96RegClass;
case 4:
return &AMDGPU::VReg_128RegClass;
case 8:
return &AMDGPU::VReg_256RegClass;
case 16: /* fall-through */
default:
llvm_unreachable("Invalid sub-register class size");
}
}
}
bool SIRegisterInfo::shouldRewriteCopySrc(
const TargetRegisterClass *DefRC,
unsigned DefSubReg,
const TargetRegisterClass *SrcRC,
unsigned SrcSubReg) const {
// We want to prefer the smallest register class possible, so we don't want to
// stop and rewrite on anything that looks like a subregister
// extract. Operations mostly don't care about the super register class, so we
// only want to stop on the most basic of copies between the same register
// class.
//
// e.g. if we have something like
// %0 = ...
// %1 = ...
// %2 = REG_SEQUENCE %0, sub0, %1, sub1, %2, sub2
// %3 = COPY %2, sub0
//
// We want to look through the COPY to find:
// => %3 = COPY %0
// Plain copy.
return getCommonSubClass(DefRC, SrcRC) != nullptr;
}
/// Returns a register that is not used at any point in the function.
/// If all registers are used, then this function will return
// AMDGPU::NoRegister.
unsigned
SIRegisterInfo::findUnusedRegister(const MachineRegisterInfo &MRI,
const TargetRegisterClass *RC,
const MachineFunction &MF) const {
for (unsigned Reg : *RC)
if (MRI.isAllocatable(Reg) && !MRI.isPhysRegUsed(Reg))
return Reg;
return AMDGPU::NoRegister;
}
ArrayRef<int16_t> SIRegisterInfo::getRegSplitParts(const TargetRegisterClass *RC,
unsigned EltSize) const {
if (EltSize == 4) {
static const int16_t Sub0_15[] = {
AMDGPU::sub0, AMDGPU::sub1, AMDGPU::sub2, AMDGPU::sub3,
AMDGPU::sub4, AMDGPU::sub5, AMDGPU::sub6, AMDGPU::sub7,
AMDGPU::sub8, AMDGPU::sub9, AMDGPU::sub10, AMDGPU::sub11,
AMDGPU::sub12, AMDGPU::sub13, AMDGPU::sub14, AMDGPU::sub15,
};
static const int16_t Sub0_7[] = {
AMDGPU::sub0, AMDGPU::sub1, AMDGPU::sub2, AMDGPU::sub3,
AMDGPU::sub4, AMDGPU::sub5, AMDGPU::sub6, AMDGPU::sub7,
};
static const int16_t Sub0_3[] = {
AMDGPU::sub0, AMDGPU::sub1, AMDGPU::sub2, AMDGPU::sub3,
};
static const int16_t Sub0_2[] = {
AMDGPU::sub0, AMDGPU::sub1, AMDGPU::sub2,
};
static const int16_t Sub0_1[] = {
AMDGPU::sub0, AMDGPU::sub1,
};
switch (AMDGPU::getRegBitWidth(*RC->MC)) {
case 32:
return {};
case 64:
return makeArrayRef(Sub0_1);
case 96:
return makeArrayRef(Sub0_2);
case 128:
return makeArrayRef(Sub0_3);
case 256:
return makeArrayRef(Sub0_7);
case 512:
return makeArrayRef(Sub0_15);
default:
llvm_unreachable("unhandled register size");
}
}
if (EltSize == 8) {
static const int16_t Sub0_15_64[] = {
AMDGPU::sub0_sub1, AMDGPU::sub2_sub3,
AMDGPU::sub4_sub5, AMDGPU::sub6_sub7,
AMDGPU::sub8_sub9, AMDGPU::sub10_sub11,
AMDGPU::sub12_sub13, AMDGPU::sub14_sub15
};
static const int16_t Sub0_7_64[] = {
AMDGPU::sub0_sub1, AMDGPU::sub2_sub3,
AMDGPU::sub4_sub5, AMDGPU::sub6_sub7
};
static const int16_t Sub0_3_64[] = {
AMDGPU::sub0_sub1, AMDGPU::sub2_sub3
};
switch (AMDGPU::getRegBitWidth(*RC->MC)) {
case 64:
return {};
case 128:
return makeArrayRef(Sub0_3_64);
case 256:
return makeArrayRef(Sub0_7_64);
case 512:
return makeArrayRef(Sub0_15_64);
default:
llvm_unreachable("unhandled register size");
}
}
assert(EltSize == 16 && "unhandled register spill split size");
static const int16_t Sub0_15_128[] = {
AMDGPU::sub0_sub1_sub2_sub3,
AMDGPU::sub4_sub5_sub6_sub7,
AMDGPU::sub8_sub9_sub10_sub11,
AMDGPU::sub12_sub13_sub14_sub15
};
static const int16_t Sub0_7_128[] = {
AMDGPU::sub0_sub1_sub2_sub3,
AMDGPU::sub4_sub5_sub6_sub7
};
switch (AMDGPU::getRegBitWidth(*RC->MC)) {
case 128:
return {};
case 256:
return makeArrayRef(Sub0_7_128);
case 512:
return makeArrayRef(Sub0_15_128);
default:
llvm_unreachable("unhandled register size");
}
}
const TargetRegisterClass*
SIRegisterInfo::getRegClassForReg(const MachineRegisterInfo &MRI,
unsigned Reg) const {
if (TargetRegisterInfo::isVirtualRegister(Reg))
return MRI.getRegClass(Reg);
return getPhysRegClass(Reg);
}
bool SIRegisterInfo::isVGPR(const MachineRegisterInfo &MRI,
unsigned Reg) const {
const TargetRegisterClass * RC = getRegClassForReg(MRI, Reg);
assert(RC && "Register class for the reg not found");
return hasVGPRs(RC);
}
bool SIRegisterInfo::shouldCoalesce(MachineInstr *MI,
const TargetRegisterClass *SrcRC,
unsigned SubReg,
const TargetRegisterClass *DstRC,
unsigned DstSubReg,
const TargetRegisterClass *NewRC,
LiveIntervals &LIS) const {
unsigned SrcSize = getRegSizeInBits(*SrcRC);
unsigned DstSize = getRegSizeInBits(*DstRC);
unsigned NewSize = getRegSizeInBits(*NewRC);
// Do not increase size of registers beyond dword, we would need to allocate
// adjacent registers and constraint regalloc more than needed.
// Always allow dword coalescing.
if (SrcSize <= 32 || DstSize <= 32)
return true;
return NewSize <= DstSize || NewSize <= SrcSize;
}
unsigned SIRegisterInfo::getRegPressureLimit(const TargetRegisterClass *RC,
MachineFunction &MF) const {
const GCNSubtarget &ST = MF.getSubtarget<GCNSubtarget>();
const SIMachineFunctionInfo *MFI = MF.getInfo<SIMachineFunctionInfo>();
unsigned Occupancy = ST.getOccupancyWithLocalMemSize(MFI->getLDSSize(),
MF.getFunction());
switch (RC->getID()) {
default:
return AMDGPURegisterInfo::getRegPressureLimit(RC, MF);
case AMDGPU::VGPR_32RegClassID:
return std::min(ST.getMaxNumVGPRs(Occupancy), ST.getMaxNumVGPRs(MF));
case AMDGPU::SGPR_32RegClassID:
return std::min(ST.getMaxNumSGPRs(Occupancy, true), ST.getMaxNumSGPRs(MF));
}
}
unsigned SIRegisterInfo::getRegPressureSetLimit(const MachineFunction &MF,
unsigned Idx) const {
if (Idx == getVGPRPressureSet())
return getRegPressureLimit(&AMDGPU::VGPR_32RegClass,
const_cast<MachineFunction &>(MF));
if (Idx == getSGPRPressureSet())
return getRegPressureLimit(&AMDGPU::SGPR_32RegClass,
const_cast<MachineFunction &>(MF));
return AMDGPURegisterInfo::getRegPressureSetLimit(MF, Idx);
}
const int *SIRegisterInfo::getRegUnitPressureSets(unsigned RegUnit) const {
static const int Empty[] = { -1 };
if (hasRegUnit(AMDGPU::M0, RegUnit))
return Empty;
return AMDGPURegisterInfo::getRegUnitPressureSets(RegUnit);
}
unsigned SIRegisterInfo::getReturnAddressReg(const MachineFunction &MF) const {
// Not a callee saved register.
return AMDGPU::SGPR30_SGPR31;
}
const TargetRegisterClass *
SIRegisterInfo::getConstrainedRegClassForOperand(const MachineOperand &MO,
const MachineRegisterInfo &MRI) const {
unsigned Size = getRegSizeInBits(MO.getReg(), MRI);
const RegisterBank *RB = MRI.getRegBankOrNull(MO.getReg());
if (!RB)
return nullptr;
switch (Size) {
case 32:
return RB->getID() == AMDGPU::VGPRRegBankID ? &AMDGPU::VGPR_32RegClass :
&AMDGPU::SReg_32_XM0RegClass;
case 64:
return RB->getID() == AMDGPU::VGPRRegBankID ? &AMDGPU::VReg_64RegClass :
&AMDGPU::SReg_64_XEXECRegClass;
case 96:
return RB->getID() == AMDGPU::VGPRRegBankID ? &AMDGPU::VReg_96RegClass :
nullptr;
case 128:
return RB->getID() == AMDGPU::VGPRRegBankID ? &AMDGPU::VReg_128RegClass :
&AMDGPU::SReg_128RegClass;
default:
llvm_unreachable("not implemented");
}
}