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llvm / llvm-project / 4b30076f16fc55891da8952bda3f2d81dbeec5a5 / . / llvm / lib / Target / AMDGPU / SIRegisterInfo.cpp
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//===-- SIRegisterInfo.cpp - SI Register Information ---------------------===//
//
// 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
/// SI implementation of the TargetRegisterInfo class.
//
//===----------------------------------------------------------------------===//
#include "SIRegisterInfo.h"
#include "AMDGPU.h"
#include "AMDGPURegisterBankInfo.h"
#include "GCNSubtarget.h"
#include "MCTargetDesc/AMDGPUInstPrinter.h"
#include "MCTargetDesc/AMDGPUMCTargetDesc.h"
#include "SIMachineFunctionInfo.h"
#include "llvm/CodeGen/LiveIntervals.h"
#include "llvm/CodeGen/MachineDominators.h"
#include "llvm/CodeGen/RegisterScavenging.h"
using namespace llvm;
#define GET_REGINFO_TARGET_DESC
#include "AMDGPUGenRegisterInfo.inc"
static cl::opt<bool> EnableSpillSGPRToVGPR(
"amdgpu-spill-sgpr-to-vgpr",
cl::desc("Enable spilling VGPRs to SGPRs"),
cl::ReallyHidden,
cl::init(true));
std::array<std::vector<int16_t>, 16> SIRegisterInfo::RegSplitParts;
std::array<std::array<uint16_t, 32>, 9> SIRegisterInfo::SubRegFromChannelTable;
// Map numbers of DWORDs to indexes in SubRegFromChannelTable.
// Valid indexes are shifted 1, such that a 0 mapping means unsupported.
// e.g. for 8 DWORDs (256-bit), SubRegFromChannelTableWidthMap[8] = 8,
// meaning index 7 in SubRegFromChannelTable.
static const std::array<unsigned, 17> SubRegFromChannelTableWidthMap = {
0, 1, 2, 3, 4, 5, 6, 7, 8, 0, 0, 0, 0, 0, 0, 0, 9};
namespace llvm {
// A temporary struct to spill SGPRs.
// This is mostly to spill SGPRs to memory. Spilling SGPRs into VGPR lanes emits
// just v_writelane and v_readlane.
//
// When spilling to memory, the SGPRs are written into VGPR lanes and the VGPR
// is saved to scratch (or the other way around for loads).
// For this, a VGPR is required where the needed lanes can be clobbered. The
// RegScavenger can provide a VGPR where currently active lanes can be
// clobbered, but we still need to save inactive lanes.
// The high-level steps are:
// - Try to scavenge SGPR(s) to save exec
// - Try to scavenge VGPR
// - Save needed, all or inactive lanes of a TmpVGPR
// - Spill/Restore SGPRs using TmpVGPR
// - Restore TmpVGPR
//
// To save all lanes of TmpVGPR, exec needs to be saved and modified. If we
// cannot scavenge temporary SGPRs to save exec, we use the following code:
// buffer_store_dword TmpVGPR ; only if active lanes need to be saved
// s_not exec, exec
// buffer_store_dword TmpVGPR ; save inactive lanes
// s_not exec, exec
struct SGPRSpillBuilder {
struct PerVGPRData {
unsigned PerVGPR;
unsigned NumVGPRs;
int64_t VGPRLanes;
};
// The SGPR to save
Register SuperReg;
MachineBasicBlock::iterator MI;
ArrayRef<int16_t> SplitParts;
unsigned NumSubRegs;
bool IsKill;
const DebugLoc &DL;
/* When spilling to stack */
// The SGPRs are written into this VGPR, which is then written to scratch
// (or vice versa for loads).
Register TmpVGPR = AMDGPU::NoRegister;
// Temporary spill slot to save TmpVGPR to.
int TmpVGPRIndex = 0;
// If TmpVGPR is live before the spill or if it is scavenged.
bool TmpVGPRLive = false;
// Scavenged SGPR to save EXEC.
Register SavedExecReg = AMDGPU::NoRegister;
// Stack index to write the SGPRs to.
int Index;
unsigned EltSize = 4;
RegScavenger *RS;
MachineBasicBlock *MBB;
MachineFunction &MF;
SIMachineFunctionInfo &MFI;
const SIInstrInfo &TII;
const SIRegisterInfo &TRI;
bool IsWave32;
Register ExecReg;
unsigned MovOpc;
unsigned NotOpc;
SGPRSpillBuilder(const SIRegisterInfo &TRI, const SIInstrInfo &TII,
bool IsWave32, MachineBasicBlock::iterator MI, int Index,
RegScavenger *RS)
: SGPRSpillBuilder(TRI, TII, IsWave32, MI, MI->getOperand(0).getReg(),
MI->getOperand(0).isKill(), Index, RS) {}
SGPRSpillBuilder(const SIRegisterInfo &TRI, const SIInstrInfo &TII,
bool IsWave32, MachineBasicBlock::iterator MI, Register Reg,
bool IsKill, int Index, RegScavenger *RS)
: SuperReg(Reg), MI(MI), IsKill(IsKill), DL(MI->getDebugLoc()),
Index(Index), RS(RS), MBB(MI->getParent()), MF(*MBB->getParent()),
MFI(*MF.getInfo<SIMachineFunctionInfo>()), TII(TII), TRI(TRI),
IsWave32(IsWave32) {
const TargetRegisterClass *RC = TRI.getPhysRegClass(SuperReg);
SplitParts = TRI.getRegSplitParts(RC, EltSize);
NumSubRegs = SplitParts.empty() ? 1 : SplitParts.size();
if (IsWave32) {
ExecReg = AMDGPU::EXEC_LO;
MovOpc = AMDGPU::S_MOV_B32;
NotOpc = AMDGPU::S_NOT_B32;
} else {
ExecReg = AMDGPU::EXEC;
MovOpc = AMDGPU::S_MOV_B64;
NotOpc = AMDGPU::S_NOT_B64;
}
assert(SuperReg != AMDGPU::M0 && "m0 should never spill");
assert(SuperReg != AMDGPU::EXEC_LO && SuperReg != AMDGPU::EXEC_HI &&
SuperReg != AMDGPU::EXEC && "exec should never spill");
}
PerVGPRData getPerVGPRData() {
PerVGPRData Data;
Data.PerVGPR = IsWave32 ? 32 : 64;
Data.NumVGPRs = (NumSubRegs + (Data.PerVGPR - 1)) / Data.PerVGPR;
Data.VGPRLanes = (1LL << std::min(Data.PerVGPR, NumSubRegs)) - 1LL;
return Data;
}
// Tries to scavenge SGPRs to save EXEC and a VGPR. Uses v0 if no VGPR is
// free.
// Writes these instructions if an SGPR can be scavenged:
// s_mov_b64 s[6:7], exec ; Save exec
// s_mov_b64 exec, 3 ; Wanted lanemask
// buffer_store_dword v1 ; Write scavenged VGPR to emergency slot
//
// Writes these instructions if no SGPR can be scavenged:
// buffer_store_dword v0 ; Only if no free VGPR was found
// s_not_b64 exec, exec
// buffer_store_dword v0 ; Save inactive lanes
// ; exec stays inverted, it is flipped back in
// ; restore.
void prepare() {
// Scavenged temporary VGPR to use. It must be scavenged once for any number
// of spilled subregs.
// FIXME: The liveness analysis is limited and does not tell if a register
// is in use in lanes that are currently inactive. We can never be sure if
// a register as actually in use in another lane, so we need to save all
// used lanes of the chosen VGPR.
assert(RS && "Cannot spill SGPR to memory without RegScavenger");
TmpVGPR = RS->scavengeRegister(&AMDGPU::VGPR_32RegClass, MI, 0, false);
// Reserve temporary stack slot
TmpVGPRIndex = MFI.getScavengeFI(MF.getFrameInfo(), TRI);
if (TmpVGPR) {
// Found a register that is dead in the currently active lanes, we only
// need to spill inactive lanes.
TmpVGPRLive = false;
} else {
// Pick v0 because it doesn't make a difference.
TmpVGPR = AMDGPU::VGPR0;
TmpVGPRLive = true;
}
// Try to scavenge SGPRs to save exec
assert(!SavedExecReg && "Exec is already saved, refuse to save again");
const TargetRegisterClass &RC =
IsWave32 ? AMDGPU::SGPR_32RegClass : AMDGPU::SGPR_64RegClass;
RS->setRegUsed(SuperReg);
SavedExecReg = RS->scavengeRegister(&RC, MI, 0, false);
int64_t VGPRLanes = getPerVGPRData().VGPRLanes;
if (SavedExecReg) {
RS->setRegUsed(SavedExecReg);
// Set exec to needed lanes
BuildMI(*MBB, MI, DL, TII.get(MovOpc), SavedExecReg).addReg(ExecReg);
auto I =
BuildMI(*MBB, MI, DL, TII.get(MovOpc), ExecReg).addImm(VGPRLanes);
if (!TmpVGPRLive)
I.addReg(TmpVGPR, RegState::ImplicitDefine);
// Spill needed lanes
TRI.buildVGPRSpillLoadStore(*this, TmpVGPRIndex, 0, /*IsLoad*/ false);
} else {
// Spill active lanes
if (TmpVGPRLive)
TRI.buildVGPRSpillLoadStore(*this, TmpVGPRIndex, 0, /*IsLoad*/ false,
/*IsKill*/ false);
// Spill inactive lanes
auto I = BuildMI(*MBB, MI, DL, TII.get(NotOpc), ExecReg).addReg(ExecReg);
if (!TmpVGPRLive)
I.addReg(TmpVGPR, RegState::ImplicitDefine);
TRI.buildVGPRSpillLoadStore(*this, TmpVGPRIndex, 0, /*IsLoad*/ false);
}
}
// Writes these instructions if an SGPR can be scavenged:
// buffer_load_dword v1 ; Write scavenged VGPR to emergency slot
// s_waitcnt vmcnt(0) ; If a free VGPR was found
// s_mov_b64 exec, s[6:7] ; Save exec
//
// Writes these instructions if no SGPR can be scavenged:
// buffer_load_dword v0 ; Restore inactive lanes
// s_waitcnt vmcnt(0) ; If a free VGPR was found
// s_not_b64 exec, exec
// buffer_load_dword v0 ; Only if no free VGPR was found
void restore() {
if (SavedExecReg) {
// Restore used lanes
TRI.buildVGPRSpillLoadStore(*this, TmpVGPRIndex, 0, /*IsLoad*/ true,
/*IsKill*/ false);
// Restore exec
auto I = BuildMI(*MBB, MI, DL, TII.get(MovOpc), ExecReg)
.addReg(SavedExecReg, RegState::Kill);
// Add an implicit use of the load so it is not dead.
// FIXME This inserts an unnecessary waitcnt
if (!TmpVGPRLive) {
I.addReg(TmpVGPR, RegState::ImplicitKill);
}
} else {
// Restore inactive lanes
TRI.buildVGPRSpillLoadStore(*this, TmpVGPRIndex, 0, /*IsLoad*/ true,
/*IsKill*/ false);
auto I = BuildMI(*MBB, MI, DL, TII.get(NotOpc), ExecReg).addReg(ExecReg);
if (!TmpVGPRLive) {
I.addReg(TmpVGPR, RegState::ImplicitKill);
}
// Restore active lanes
if (TmpVGPRLive)
TRI.buildVGPRSpillLoadStore(*this, TmpVGPRIndex, 0, /*IsLoad*/ true);
}
}
// Write TmpVGPR to memory or read TmpVGPR from memory.
// Either using a single buffer_load/store if exec is set to the needed mask
// or using
// buffer_load
// s_not exec, exec
// buffer_load
// s_not exec, exec
void readWriteTmpVGPR(unsigned Offset, bool IsLoad) {
if (SavedExecReg) {
// Spill needed lanes
TRI.buildVGPRSpillLoadStore(*this, Index, Offset, IsLoad);
} else {
// Spill active lanes
TRI.buildVGPRSpillLoadStore(*this, Index, Offset, IsLoad,
/*IsKill*/ false);
// Spill inactive lanes
BuildMI(*MBB, MI, DL, TII.get(NotOpc), ExecReg).addReg(ExecReg);
TRI.buildVGPRSpillLoadStore(*this, Index, Offset, IsLoad);
BuildMI(*MBB, MI, DL, TII.get(NotOpc), ExecReg).addReg(ExecReg);
}
}
void setMI(MachineBasicBlock *NewMBB, MachineBasicBlock::iterator NewMI) {
assert(MBB->getParent() == &MF);
MI = NewMI;
MBB = NewMBB;
}
};
} // namespace llvm
SIRegisterInfo::SIRegisterInfo(const GCNSubtarget &ST)
: AMDGPUGenRegisterInfo(AMDGPU::PC_REG, ST.getAMDGPUDwarfFlavour()), ST(ST),
SpillSGPRToVGPR(EnableSpillSGPRToVGPR), isWave32(ST.isWave32()) {
assert(getSubRegIndexLaneMask(AMDGPU::sub0).getAsInteger() == 3 &&
getSubRegIndexLaneMask(AMDGPU::sub31).getAsInteger() == (3ULL << 62) &&
(getSubRegIndexLaneMask(AMDGPU::lo16) |
getSubRegIndexLaneMask(AMDGPU::hi16)).getAsInteger() ==
getSubRegIndexLaneMask(AMDGPU::sub0).getAsInteger() &&
"getNumCoveredRegs() will not work with generated subreg masks!");
RegPressureIgnoredUnits.resize(getNumRegUnits());
RegPressureIgnoredUnits.set(
*MCRegUnitIterator(MCRegister::from(AMDGPU::M0), this));
for (auto Reg : AMDGPU::VGPR_HI16RegClass)
RegPressureIgnoredUnits.set(*MCRegUnitIterator(Reg, this));
// HACK: Until this is fully tablegen'd.
static llvm::once_flag InitializeRegSplitPartsFlag;
static auto InitializeRegSplitPartsOnce = [this]() {
for (unsigned Idx = 1, E = getNumSubRegIndices() - 1; Idx < E; ++Idx) {
unsigned Size = getSubRegIdxSize(Idx);
if (Size & 31)
continue;
std::vector<int16_t> &Vec = RegSplitParts[Size / 32 - 1];
unsigned Pos = getSubRegIdxOffset(Idx);
if (Pos % Size)
continue;
Pos /= Size;
if (Vec.empty()) {
unsigned MaxNumParts = 1024 / Size; // Maximum register is 1024 bits.
Vec.resize(MaxNumParts);
}
Vec[Pos] = Idx;
}
};
static llvm::once_flag InitializeSubRegFromChannelTableFlag;
static auto InitializeSubRegFromChannelTableOnce = [this]() {
for (auto &Row : SubRegFromChannelTable)
Row.fill(AMDGPU::NoSubRegister);
for (uint16_t Idx = 1; Idx < getNumSubRegIndices(); ++Idx) {
unsigned Width = AMDGPUSubRegIdxRanges[Idx].Size / 32;
unsigned Offset = AMDGPUSubRegIdxRanges[Idx].Offset / 32;
assert(Width < SubRegFromChannelTableWidthMap.size());
Width = SubRegFromChannelTableWidthMap[Width];
if (Width == 0)
continue;
unsigned TableIdx = Width - 1;
assert(TableIdx < SubRegFromChannelTable.size());
assert(Offset < SubRegFromChannelTable[TableIdx].size());
SubRegFromChannelTable[TableIdx][Offset] = Idx;
}
};
llvm::call_once(InitializeRegSplitPartsFlag, InitializeRegSplitPartsOnce);
llvm::call_once(InitializeSubRegFromChannelTableFlag,
InitializeSubRegFromChannelTableOnce);
}
void SIRegisterInfo::reserveRegisterTuples(BitVector &Reserved,
MCRegister Reg) const {
MCRegAliasIterator R(Reg, this, true);
for (; R.isValid(); ++R)
Reserved.set(*R);
}
// Forced to be here by one .inc
const MCPhysReg *SIRegisterInfo::getCalleeSavedRegs(
const MachineFunction *MF) const {
CallingConv::ID CC = MF->getFunction().getCallingConv();
switch (CC) {
case CallingConv::C:
case CallingConv::Fast:
case CallingConv::Cold:
return MF->getSubtarget<GCNSubtarget>().hasGFX90AInsts()
? CSR_AMDGPU_HighRegs_With_AGPRs_SaveList
: CSR_AMDGPU_HighRegs_SaveList;
case CallingConv::AMDGPU_Gfx:
return MF->getSubtarget<GCNSubtarget>().hasGFX90AInsts()
? CSR_AMDGPU_SI_Gfx_With_AGPRs_SaveList
: CSR_AMDGPU_SI_Gfx_SaveList;
default: {
// Dummy to not crash RegisterClassInfo.
static const MCPhysReg NoCalleeSavedReg = AMDGPU::NoRegister;
return &NoCalleeSavedReg;
}
}
}
const MCPhysReg *
SIRegisterInfo::getCalleeSavedRegsViaCopy(const MachineFunction *MF) const {
return nullptr;
}
const uint32_t *SIRegisterInfo::getCallPreservedMask(const MachineFunction &MF,
CallingConv::ID CC) const {
switch (CC) {
case CallingConv::C:
case CallingConv::Fast:
case CallingConv::Cold:
return MF.getSubtarget<GCNSubtarget>().hasGFX90AInsts()
? CSR_AMDGPU_HighRegs_With_AGPRs_RegMask
: CSR_AMDGPU_HighRegs_RegMask;
case CallingConv::AMDGPU_Gfx:
return MF.getSubtarget<GCNSubtarget>().hasGFX90AInsts()
? CSR_AMDGPU_SI_Gfx_With_AGPRs_RegMask
: CSR_AMDGPU_SI_Gfx_RegMask;
default:
return nullptr;
}
}
const uint32_t *SIRegisterInfo::getNoPreservedMask() const {
return CSR_AMDGPU_NoRegs_RegMask;
}
const TargetRegisterClass *
SIRegisterInfo::getLargestLegalSuperClass(const TargetRegisterClass *RC,
const MachineFunction &MF) const {
// FIXME: Should have a helper function like getEquivalentVGPRClass to get the
// equivalent AV class. If used one, the verifier will crash after
// RegBankSelect in the GISel flow. The aligned regclasses are not fully given
// until Instruction selection.
if (MF.getSubtarget<GCNSubtarget>().hasMAIInsts() &&
(isVGPRClass(RC) || isAGPRClass(RC))) {
if (RC == &AMDGPU::VGPR_32RegClass || RC == &AMDGPU::AGPR_32RegClass)
return &AMDGPU::AV_32RegClass;
if (RC == &AMDGPU::VReg_64RegClass || RC == &AMDGPU::AReg_64RegClass)
return &AMDGPU::AV_64RegClass;
if (RC == &AMDGPU::VReg_64_Align2RegClass ||
RC == &AMDGPU::AReg_64_Align2RegClass)
return &AMDGPU::AV_64_Align2RegClass;
if (RC == &AMDGPU::VReg_96RegClass || RC == &AMDGPU::AReg_96RegClass)
return &AMDGPU::AV_96RegClass;
if (RC == &AMDGPU::VReg_96_Align2RegClass ||
RC == &AMDGPU::AReg_96_Align2RegClass)
return &AMDGPU::AV_96_Align2RegClass;
if (RC == &AMDGPU::VReg_128RegClass || RC == &AMDGPU::AReg_128RegClass)
return &AMDGPU::AV_128RegClass;
if (RC == &AMDGPU::VReg_128_Align2RegClass ||
RC == &AMDGPU::AReg_128_Align2RegClass)
return &AMDGPU::AV_128_Align2RegClass;
if (RC == &AMDGPU::VReg_160RegClass || RC == &AMDGPU::AReg_160RegClass)
return &AMDGPU::AV_160RegClass;
if (RC == &AMDGPU::VReg_160_Align2RegClass ||
RC == &AMDGPU::AReg_160_Align2RegClass)
return &AMDGPU::AV_160_Align2RegClass;
if (RC == &AMDGPU::VReg_192RegClass || RC == &AMDGPU::AReg_192RegClass)
return &AMDGPU::AV_192RegClass;
if (RC == &AMDGPU::VReg_192_Align2RegClass ||
RC == &AMDGPU::AReg_192_Align2RegClass)
return &AMDGPU::AV_192_Align2RegClass;
if (RC == &AMDGPU::VReg_256RegClass || RC == &AMDGPU::AReg_256RegClass)
return &AMDGPU::AV_256RegClass;
if (RC == &AMDGPU::VReg_256_Align2RegClass ||
RC == &AMDGPU::AReg_256_Align2RegClass)
return &AMDGPU::AV_256_Align2RegClass;
if (RC == &AMDGPU::VReg_512RegClass || RC == &AMDGPU::AReg_512RegClass)
return &AMDGPU::AV_512RegClass;
if (RC == &AMDGPU::VReg_512_Align2RegClass ||
RC == &AMDGPU::AReg_512_Align2RegClass)
return &AMDGPU::AV_512_Align2RegClass;
if (RC == &AMDGPU::VReg_1024RegClass || RC == &AMDGPU::AReg_1024RegClass)
return &AMDGPU::AV_1024RegClass;
if (RC == &AMDGPU::VReg_1024_Align2RegClass ||
RC == &AMDGPU::AReg_1024_Align2RegClass)
return &AMDGPU::AV_1024_Align2RegClass;
}
return TargetRegisterInfo::getLargestLegalSuperClass(RC, MF);
}
Register SIRegisterInfo::getFrameRegister(const MachineFunction &MF) const {
const SIFrameLowering *TFI =
MF.getSubtarget<GCNSubtarget>().getFrameLowering();
const SIMachineFunctionInfo *FuncInfo = MF.getInfo<SIMachineFunctionInfo>();
// During ISel lowering we always reserve the stack pointer in entry
// functions, but never actually want to reference it when accessing our own
// frame. If we need a frame pointer we use it, but otherwise we can just use
// an immediate "0" which we represent by returning NoRegister.
if (FuncInfo->isEntryFunction()) {
return TFI->hasFP(MF) ? FuncInfo->getFrameOffsetReg() : Register();
}
return TFI->hasFP(MF) ? FuncInfo->getFrameOffsetReg()
: FuncInfo->getStackPtrOffsetReg();
}
bool SIRegisterInfo::hasBasePointer(const MachineFunction &MF) const {
// When we need stack realignment, we can't reference off of the
// stack pointer, so we reserve a base pointer.
const MachineFrameInfo &MFI = MF.getFrameInfo();
return MFI.getNumFixedObjects() && shouldRealignStack(MF);
}
Register SIRegisterInfo::getBaseRegister() const { return AMDGPU::SGPR34; }
const uint32_t *SIRegisterInfo::getAllVGPRRegMask() const {
return CSR_AMDGPU_AllVGPRs_RegMask;
}
const uint32_t *SIRegisterInfo::getAllAGPRRegMask() const {
return CSR_AMDGPU_AllAGPRs_RegMask;
}
const uint32_t *SIRegisterInfo::getAllVectorRegMask() const {
return CSR_AMDGPU_AllVectorRegs_RegMask;
}
const uint32_t *SIRegisterInfo::getAllAllocatableSRegMask() const {
return CSR_AMDGPU_AllAllocatableSRegs_RegMask;
}
unsigned SIRegisterInfo::getSubRegFromChannel(unsigned Channel,
unsigned NumRegs) {
assert(NumRegs < SubRegFromChannelTableWidthMap.size());
unsigned NumRegIndex = SubRegFromChannelTableWidthMap[NumRegs];
assert(NumRegIndex && "Not implemented");
assert(Channel < SubRegFromChannelTable[NumRegIndex - 1].size());
return SubRegFromChannelTable[NumRegIndex - 1][Channel];
}
MCRegister SIRegisterInfo::reservedPrivateSegmentBufferReg(
const MachineFunction &MF) const {
unsigned BaseIdx = alignDown(ST.getMaxNumSGPRs(MF), 4) - 4;
MCRegister BaseReg(AMDGPU::SGPR_32RegClass.getRegister(BaseIdx));
return getMatchingSuperReg(BaseReg, AMDGPU::sub0, &AMDGPU::SGPR_128RegClass);
}
BitVector SIRegisterInfo::getReservedRegs(const MachineFunction &MF) const {
BitVector Reserved(getNumRegs());
Reserved.set(AMDGPU::MODE);
// 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 src_vccz, src_execz, src_scc.
reserveRegisterTuples(Reserved, AMDGPU::SRC_VCCZ);
reserveRegisterTuples(Reserved, AMDGPU::SRC_EXECZ);
reserveRegisterTuples(Reserved, AMDGPU::SRC_SCC);
// 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 src_pops_exiting_wave_id - support is not implemented in Codegen.
reserveRegisterTuples(Reserved, AMDGPU::SRC_POPS_EXITING_WAVE_ID);
// Reserve xnack_mask registers - support is not implemented in Codegen.
reserveRegisterTuples(Reserved, AMDGPU::XNACK_MASK);
// Reserve lds_direct register - support is not implemented in Codegen.
reserveRegisterTuples(Reserved, AMDGPU::LDS_DIRECT);
// 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);
// Reserve null register - it shall never be allocated
reserveRegisterTuples(Reserved, AMDGPU::SGPR_NULL);
// Disallow vcc_hi allocation in wave32. It may be allocated but most likely
// will result in bugs.
if (isWave32) {
Reserved.set(AMDGPU::VCC);
Reserved.set(AMDGPU::VCC_HI);
}
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);
}
const SIMachineFunctionInfo *MFI = MF.getInfo<SIMachineFunctionInfo>();
unsigned MaxNumVGPRs = ST.getMaxNumVGPRs(MF);
unsigned MaxNumAGPRs = MaxNumVGPRs;
unsigned TotalNumVGPRs = AMDGPU::VGPR_32RegClass.getNumRegs();
if (ST.hasGFX90AInsts()) {
// In an entry function without calls and AGPRs used it is possible to use
// the whole register budget for VGPRs.
// TODO: it shall be possible to estimate maximum AGPR/VGPR pressure and
// split register file accordingly.
if (MFI->usesAGPRs(MF)) {
MaxNumVGPRs /= 2;
MaxNumAGPRs = MaxNumVGPRs;
} else {
if (MaxNumVGPRs > TotalNumVGPRs) {
MaxNumAGPRs = MaxNumVGPRs - TotalNumVGPRs;
MaxNumVGPRs = TotalNumVGPRs;
} else
MaxNumAGPRs = 0;
}
}
for (unsigned i = MaxNumVGPRs; i < TotalNumVGPRs; ++i) {
unsigned Reg = AMDGPU::VGPR_32RegClass.getRegister(i);
reserveRegisterTuples(Reserved, Reg);
}
for (unsigned i = MaxNumAGPRs; i < TotalNumVGPRs; ++i) {
unsigned Reg = AMDGPU::AGPR_32RegClass.getRegister(i);
reserveRegisterTuples(Reserved, Reg);
}
for (auto Reg : AMDGPU::SReg_32RegClass) {
Reserved.set(getSubReg(Reg, AMDGPU::hi16));
Register Low = getSubReg(Reg, AMDGPU::lo16);
// This is to prevent BB vcc liveness errors.
if (!AMDGPU::SGPR_LO16RegClass.contains(Low))
Reserved.set(Low);
}
for (auto Reg : AMDGPU::AGPR_32RegClass) {
Reserved.set(getSubReg(Reg, AMDGPU::hi16));
}
// Reserve all the rest AGPRs if there are no instructions to use it.
if (!ST.hasMAIInsts()) {
for (unsigned i = 0; i < MaxNumVGPRs; ++i) {
unsigned Reg = AMDGPU::AGPR_32RegClass.getRegister(i);
reserveRegisterTuples(Reserved, Reg);
}
}
Register 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);
}
// 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.
MCRegister StackPtrReg = MFI->getStackPtrOffsetReg();
if (StackPtrReg) {
reserveRegisterTuples(Reserved, StackPtrReg);
assert(!isSubRegister(ScratchRSrcReg, StackPtrReg));
}
MCRegister FrameReg = MFI->getFrameOffsetReg();
if (FrameReg) {
reserveRegisterTuples(Reserved, FrameReg);
assert(!isSubRegister(ScratchRSrcReg, FrameReg));
}
if (hasBasePointer(MF)) {
MCRegister BasePtrReg = getBaseRegister();
reserveRegisterTuples(Reserved, BasePtrReg);
assert(!isSubRegister(ScratchRSrcReg, BasePtrReg));
}
for (auto Reg : MFI->WWMReservedRegs) {
reserveRegisterTuples(Reserved, Reg.first);
}
// Reserve VGPRs used for SGPR spilling.
// Note we treat freezeReservedRegs unusually because we run register
// allocation in two phases. It's OK to re-freeze with new registers for the
// second run.
#if 0
for (auto &SpilledFI : MFI->sgpr_spill_vgprs()) {
for (auto &SpilledVGPR : SpilledFI.second)
reserveRegisterTuples(Reserved, SpilledVGPR.VGPR);
}
#endif
// FIXME: Stop using reserved registers for this.
for (MCPhysReg Reg : MFI->getAGPRSpillVGPRs())
reserveRegisterTuples(Reserved, Reg);
for (MCPhysReg Reg : MFI->getVGPRSpillAGPRs())
reserveRegisterTuples(Reserved, Reg);
for (auto SSpill : MFI->getSGPRSpillVGPRs())
reserveRegisterTuples(Reserved, SSpill.VGPR);
return Reserved;
}
bool SIRegisterInfo::shouldRealignStack(const MachineFunction &MF) const {
const SIMachineFunctionInfo *Info = MF.getInfo<SIMachineFunctionInfo>();
// On entry, the base address is 0, so it can't possibly need any more
// alignment.
// FIXME: Should be able to specify the entry frame alignment per calling
// convention instead.
if (Info->isEntryFunction())
return false;
return TargetRegisterInfo::shouldRealignStack(MF);
}
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 {
// Do not use frame virtual registers. They used to be used for SGPRs, but
// once we reach PrologEpilogInserter, we can no longer spill SGPRs. If the
// scavenger fails, we can increment/decrement the necessary SGPRs to avoid a
// spill.
return false;
}
bool SIRegisterInfo::requiresFrameIndexReplacementScavenging(
const MachineFunction &MF) const {
const MachineFrameInfo &MFI = MF.getFrameInfo();
return MFI.hasStackObjects();
}
bool SIRegisterInfo::requiresVirtualBaseRegisters(
const MachineFunction &) const {
// There are no special dedicated stack or frame pointers.
return true;
}
int64_t SIRegisterInfo::getScratchInstrOffset(const MachineInstr *MI) const {
assert(SIInstrInfo::isMUBUF(*MI) || SIInstrInfo::isFLATScratch(*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) && !SIInstrInfo::isFLATScratch(*MI))
return 0;
assert((Idx == AMDGPU::getNamedOperandIdx(MI->getOpcode(),
AMDGPU::OpName::vaddr) ||
(Idx == AMDGPU::getNamedOperandIdx(MI->getOpcode(),
AMDGPU::OpName::saddr))) &&
"Should never see frame index on non-address operand");
return getScratchInstrOffset(MI);
}
bool SIRegisterInfo::needsFrameBaseReg(MachineInstr *MI, int64_t Offset) const {
if (!SIInstrInfo::isMUBUF(*MI) && !SIInstrInfo::isFLATScratch(*MI))
return false;
int64_t FullOffset = Offset + getScratchInstrOffset(MI);
if (SIInstrInfo::isMUBUF(*MI))
return !SIInstrInfo::isLegalMUBUFImmOffset(FullOffset);
const SIInstrInfo *TII = ST.getInstrInfo();
return !TII->isLegalFLATOffset(FullOffset, AMDGPUAS::PRIVATE_ADDRESS,
SIInstrFlags::FlatScratch);
}
Register SIRegisterInfo::materializeFrameBaseRegister(MachineBasicBlock *MBB,
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 SIInstrInfo *TII = ST.getInstrInfo();
MachineRegisterInfo &MRI = MF->getRegInfo();
unsigned MovOpc = ST.enableFlatScratch() ? AMDGPU::S_MOV_B32
: AMDGPU::V_MOV_B32_e32;
Register BaseReg = MRI.createVirtualRegister(
ST.enableFlatScratch() ? &AMDGPU::SReg_32_XEXEC_HIRegClass
: &AMDGPU::VGPR_32RegClass);
if (Offset == 0) {
BuildMI(*MBB, Ins, DL, TII->get(MovOpc), BaseReg)
.addFrameIndex(FrameIdx);
return BaseReg;
}
Register OffsetReg = MRI.createVirtualRegister(&AMDGPU::SReg_32_XM0RegClass);
Register FIReg = MRI.createVirtualRegister(
ST.enableFlatScratch() ? &AMDGPU::SReg_32_XM0RegClass
: &AMDGPU::VGPR_32RegClass);
BuildMI(*MBB, Ins, DL, TII->get(AMDGPU::S_MOV_B32), OffsetReg)
.addImm(Offset);
BuildMI(*MBB, Ins, DL, TII->get(MovOpc), FIReg)
.addFrameIndex(FrameIdx);
if (ST.enableFlatScratch() ) {
BuildMI(*MBB, Ins, DL, TII->get(AMDGPU::S_ADD_I32), BaseReg)
.addReg(OffsetReg, RegState::Kill)
.addReg(FIReg);
return BaseReg;
}
TII->getAddNoCarry(*MBB, Ins, DL, BaseReg)
.addReg(OffsetReg, RegState::Kill)
.addReg(FIReg)
.addImm(0); // clamp bit
return BaseReg;
}
void SIRegisterInfo::resolveFrameIndex(MachineInstr &MI, Register BaseReg,
int64_t Offset) const {
const SIInstrInfo *TII = ST.getInstrInfo();
bool IsFlat = TII->isFLATScratch(MI);
#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, IsFlat ? AMDGPU::OpName::saddr
: AMDGPU::OpName::vaddr);
MachineOperand *OffsetOp = TII->getNamedOperand(MI, AMDGPU::OpName::offset);
int64_t NewOffset = OffsetOp->getImm() + Offset;
assert(FIOp && FIOp->isFI() && "frame index must be address operand");
assert(TII->isMUBUF(MI) || TII->isFLATScratch(MI));
if (IsFlat) {
assert(TII->isLegalFLATOffset(NewOffset, AMDGPUAS::PRIVATE_ADDRESS,
SIInstrFlags::FlatScratch) &&
"offset should be legal");
FIOp->ChangeToRegister(BaseReg, false);
OffsetOp->setImm(NewOffset);
return;
}
#ifndef NDEBUG
MachineOperand *SOffset = TII->getNamedOperand(MI, AMDGPU::OpName::soffset);
assert(SOffset->isImm() && SOffset->getImm() == 0);
#endif
assert(SIInstrInfo::isLegalMUBUFImmOffset(NewOffset) &&
"offset should be legal");
FIOp->ChangeToRegister(BaseReg, false);
OffsetOp->setImm(NewOffset);
}
bool SIRegisterInfo::isFrameOffsetLegal(const MachineInstr *MI,
Register BaseReg,
int64_t Offset) const {
if (!SIInstrInfo::isMUBUF(*MI) && !SIInstrInfo::isFLATScratch(*MI))
return false;
int64_t NewOffset = Offset + getScratchInstrOffset(MI);
if (SIInstrInfo::isMUBUF(*MI))
return SIInstrInfo::isLegalMUBUFImmOffset(NewOffset);
const SIInstrInfo *TII = ST.getInstrInfo();
return TII->isLegalFLATOffset(NewOffset, AMDGPUAS::PRIVATE_ADDRESS,
SIInstrFlags::FlatScratch);
}
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;
}
const TargetRegisterClass *
SIRegisterInfo::getCrossCopyRegClass(const TargetRegisterClass *RC) const {
if (isAGPRClass(RC) && !ST.hasGFX90AInsts())
return getEquivalentVGPRClass(RC);
return RC;
}
static unsigned getNumSubRegsForSpillOp(unsigned Op) {
switch (Op) {
case AMDGPU::SI_SPILL_S1024_SAVE:
case AMDGPU::SI_SPILL_S1024_RESTORE:
case AMDGPU::SI_SPILL_V1024_SAVE:
case AMDGPU::SI_SPILL_V1024_RESTORE:
case AMDGPU::SI_SPILL_A1024_SAVE:
case AMDGPU::SI_SPILL_A1024_RESTORE:
return 32;
case AMDGPU::SI_SPILL_S512_SAVE:
case AMDGPU::SI_SPILL_S512_RESTORE:
case AMDGPU::SI_SPILL_V512_SAVE:
case AMDGPU::SI_SPILL_V512_RESTORE:
case AMDGPU::SI_SPILL_A512_SAVE:
case AMDGPU::SI_SPILL_A512_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:
case AMDGPU::SI_SPILL_A256_SAVE:
case AMDGPU::SI_SPILL_A256_RESTORE:
return 8;
case AMDGPU::SI_SPILL_S224_SAVE:
case AMDGPU::SI_SPILL_S224_RESTORE:
case AMDGPU::SI_SPILL_V224_SAVE:
case AMDGPU::SI_SPILL_V224_RESTORE:
case AMDGPU::SI_SPILL_A224_SAVE:
case AMDGPU::SI_SPILL_A224_RESTORE:
return 7;
case AMDGPU::SI_SPILL_S192_SAVE:
case AMDGPU::SI_SPILL_S192_RESTORE:
case AMDGPU::SI_SPILL_V192_SAVE:
case AMDGPU::SI_SPILL_V192_RESTORE:
case AMDGPU::SI_SPILL_A192_SAVE:
case AMDGPU::SI_SPILL_A192_RESTORE:
return 6;
case AMDGPU::SI_SPILL_S160_SAVE:
case AMDGPU::SI_SPILL_S160_RESTORE:
case AMDGPU::SI_SPILL_V160_SAVE:
case AMDGPU::SI_SPILL_V160_RESTORE:
case AMDGPU::SI_SPILL_A160_SAVE:
case AMDGPU::SI_SPILL_A160_RESTORE:
return 5;
case AMDGPU::SI_SPILL_S128_SAVE:
case AMDGPU::SI_SPILL_S128_RESTORE:
case AMDGPU::SI_SPILL_V128_SAVE:
case AMDGPU::SI_SPILL_V128_RESTORE:
case AMDGPU::SI_SPILL_A128_SAVE:
case AMDGPU::SI_SPILL_A128_RESTORE:
return 4;
case AMDGPU::SI_SPILL_S96_SAVE:
case AMDGPU::SI_SPILL_S96_RESTORE:
case AMDGPU::SI_SPILL_V96_SAVE:
case AMDGPU::SI_SPILL_V96_RESTORE:
case AMDGPU::SI_SPILL_A96_SAVE:
case AMDGPU::SI_SPILL_A96_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:
case AMDGPU::SI_SPILL_A64_SAVE:
case AMDGPU::SI_SPILL_A64_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:
case AMDGPU::SI_SPILL_A32_SAVE:
case AMDGPU::SI_SPILL_A32_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;
}
}
static MachineInstrBuilder spillVGPRtoAGPR(const GCNSubtarget &ST,
MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI,
int Index, unsigned Lane,
unsigned ValueReg, bool IsKill) {
MachineFunction *MF = MBB.getParent();
SIMachineFunctionInfo *MFI = MF->getInfo<SIMachineFunctionInfo>();
const SIInstrInfo *TII = ST.getInstrInfo();
MCPhysReg Reg = MFI->getVGPRToAGPRSpill(Index, Lane);
if (Reg == AMDGPU::NoRegister)
return MachineInstrBuilder();
bool IsStore = MI->mayStore();
MachineRegisterInfo &MRI = MF->getRegInfo();
auto *TRI = static_cast<const SIRegisterInfo*>(MRI.getTargetRegisterInfo());
unsigned Dst = IsStore ? Reg : ValueReg;
unsigned Src = IsStore ? ValueReg : Reg;
bool IsVGPR = TRI->isVGPR(MRI, Reg);
DebugLoc DL = MI->getDebugLoc();
if (IsVGPR == TRI->isVGPR(MRI, ValueReg)) {
// Spiller during regalloc may restore a spilled register to its superclass.
// It could result in AGPR spills restored to VGPRs or the other way around,
// making the src and dst with identical regclasses at this point. It just
// needs a copy in such cases.
auto CopyMIB = BuildMI(MBB, MI, DL, TII->get(AMDGPU::COPY), Dst)
.addReg(Src, getKillRegState(IsKill));
CopyMIB->setAsmPrinterFlag(MachineInstr::ReloadReuse);
return CopyMIB;
}
unsigned Opc = (IsStore ^ IsVGPR) ? AMDGPU::V_ACCVGPR_WRITE_B32_e64
: AMDGPU::V_ACCVGPR_READ_B32_e64;
auto MIB = BuildMI(MBB, MI, DL, TII->get(Opc), Dst)
.addReg(Src, getKillRegState(IsKill));
MIB->setAsmPrinterFlag(MachineInstr::ReloadReuse);
return MIB;
}
// 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 GCNSubtarget &ST,
MachineFrameInfo &MFI,
MachineBasicBlock::iterator MI,
int Index,
int64_t Offset) {
const SIInstrInfo *TII = ST.getInstrInfo();
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);
if (spillVGPRtoAGPR(ST, *MBB, MI, Index, 0, Reg->getReg(), false).getInstr())
return true;
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) // cpol
.addImm(0) // tfe
.addImm(0) // swz
.cloneMemRefs(*MI);
const MachineOperand *VDataIn = TII->getNamedOperand(*MI,
AMDGPU::OpName::vdata_in);
if (VDataIn)
NewMI.add(*VDataIn);
return true;
}
static unsigned getFlatScratchSpillOpcode(const SIInstrInfo *TII,
unsigned LoadStoreOp,
unsigned EltSize) {
bool IsStore = TII->get(LoadStoreOp).mayStore();
bool UseST =
AMDGPU::getNamedOperandIdx(LoadStoreOp, AMDGPU::OpName::vaddr) < 0 &&
AMDGPU::getNamedOperandIdx(LoadStoreOp, AMDGPU::OpName::saddr) < 0;
switch (EltSize) {
case 4:
LoadStoreOp = IsStore ? AMDGPU::SCRATCH_STORE_DWORD_SADDR
: AMDGPU::SCRATCH_LOAD_DWORD_SADDR;
break;
case 8:
LoadStoreOp = IsStore ? AMDGPU::SCRATCH_STORE_DWORDX2_SADDR
: AMDGPU::SCRATCH_LOAD_DWORDX2_SADDR;
break;
case 12:
LoadStoreOp = IsStore ? AMDGPU::SCRATCH_STORE_DWORDX3_SADDR
: AMDGPU::SCRATCH_LOAD_DWORDX3_SADDR;
break;
case 16:
LoadStoreOp = IsStore ? AMDGPU::SCRATCH_STORE_DWORDX4_SADDR
: AMDGPU::SCRATCH_LOAD_DWORDX4_SADDR;
break;
default:
llvm_unreachable("Unexpected spill load/store size!");
}
if (UseST)
LoadStoreOp = AMDGPU::getFlatScratchInstSTfromSS(LoadStoreOp);
return LoadStoreOp;
}
void SIRegisterInfo::buildSpillLoadStore(
MachineBasicBlock &MBB, MachineBasicBlock::iterator MI, const DebugLoc &DL,
unsigned LoadStoreOp, int Index, Register ValueReg, bool IsKill,
MCRegister ScratchOffsetReg, int64_t InstOffset, MachineMemOperand *MMO,
RegScavenger *RS, LivePhysRegs *LiveRegs) const {
assert((!RS || !LiveRegs) && "Only RS or LiveRegs can be set but not both");
MachineFunction *MF = MBB.getParent();
const SIInstrInfo *TII = ST.getInstrInfo();
const MachineFrameInfo &MFI = MF->getFrameInfo();
const SIMachineFunctionInfo *FuncInfo = MF->getInfo<SIMachineFunctionInfo>();
const MCInstrDesc *Desc = &TII->get(LoadStoreOp);
bool IsStore = Desc->mayStore();
bool IsFlat = TII->isFLATScratch(LoadStoreOp);
bool Scavenged = false;
MCRegister SOffset = ScratchOffsetReg;
const TargetRegisterClass *RC = getRegClassForReg(MF->getRegInfo(), ValueReg);
// On gfx90a+ AGPR is a regular VGPR acceptable for loads and stores.
const bool IsAGPR = !ST.hasGFX90AInsts() && isAGPRClass(RC);
const unsigned RegWidth = AMDGPU::getRegBitWidth(RC->getID()) / 8;
// Always use 4 byte operations for AGPRs because we need to scavenge
// a temporary VGPR.
unsigned EltSize = (IsFlat && !IsAGPR) ? std::min(RegWidth, 16u) : 4u;
unsigned NumSubRegs = RegWidth / EltSize;
unsigned Size = NumSubRegs * EltSize;
unsigned RemSize = RegWidth - Size;
unsigned NumRemSubRegs = RemSize ? 1 : 0;
int64_t Offset = InstOffset + MFI.getObjectOffset(Index);
int64_t MaxOffset = Offset + Size + RemSize - EltSize;
int64_t ScratchOffsetRegDelta = 0;
if (IsFlat && EltSize > 4) {
LoadStoreOp = getFlatScratchSpillOpcode(TII, LoadStoreOp, EltSize);
Desc = &TII->get(LoadStoreOp);
}
Align Alignment = MFI.getObjectAlign(Index);
const MachinePointerInfo &BasePtrInfo = MMO->getPointerInfo();
assert((IsFlat || ((Offset % EltSize) == 0)) &&
"unexpected VGPR spill offset");
bool IsOffsetLegal =
IsFlat ? TII->isLegalFLATOffset(MaxOffset, AMDGPUAS::PRIVATE_ADDRESS,
SIInstrFlags::FlatScratch)
: SIInstrInfo::isLegalMUBUFImmOffset(MaxOffset);
if (!IsOffsetLegal || (IsFlat && !SOffset && !ST.hasFlatScratchSTMode())) {
SOffset = MCRegister();
// We currently only support spilling VGPRs to EltSize boundaries, meaning
// we can simplify the adjustment of Offset here to just scale with
// WavefrontSize.
if (!IsFlat)
Offset *= ST.getWavefrontSize();
// We don't have access to the register scavenger if this function is called
// during PEI::scavengeFrameVirtualRegs() so use LiveRegs in this case.
if (RS) {
SOffset = RS->scavengeRegister(&AMDGPU::SGPR_32RegClass, MI, 0, false);
} else if (LiveRegs) {
for (MCRegister Reg : AMDGPU::SGPR_32RegClass) {
if (LiveRegs->available(MF->getRegInfo(), Reg)) {
SOffset = Reg;
break;
}
}
}
if (!SOffset) {
// 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 or StackPtrOffset
// register, and then subtract the offset after the spill to return the
// register to it's original value.
if (!ScratchOffsetReg)
ScratchOffsetReg = FuncInfo->getStackPtrOffsetReg();
SOffset = ScratchOffsetReg;
ScratchOffsetRegDelta = Offset;
} else {
Scavenged = true;
}
if (!SOffset)
report_fatal_error("could not scavenge SGPR to spill in entry function");
if (ScratchOffsetReg == AMDGPU::NoRegister) {
BuildMI(MBB, MI, DL, TII->get(AMDGPU::S_MOV_B32), SOffset).addImm(Offset);
} else {
BuildMI(MBB, MI, DL, TII->get(AMDGPU::S_ADD_I32), SOffset)
.addReg(ScratchOffsetReg)
.addImm(Offset);
}
Offset = 0;
}
if (IsFlat && SOffset == AMDGPU::NoRegister) {
assert(AMDGPU::getNamedOperandIdx(LoadStoreOp, AMDGPU::OpName::vaddr) < 0
&& "Unexpected vaddr for flat scratch with a FI operand");
assert(ST.hasFlatScratchSTMode());
LoadStoreOp = AMDGPU::getFlatScratchInstSTfromSS(LoadStoreOp);
Desc = &TII->get(LoadStoreOp);
}
Register TmpReg;
for (unsigned i = 0, e = NumSubRegs + NumRemSubRegs, RegOffset = 0; i != e;
++i, RegOffset += EltSize) {
if (i == NumSubRegs) {
EltSize = RemSize;
LoadStoreOp = getFlatScratchSpillOpcode(TII, LoadStoreOp, EltSize);
}
Desc = &TII->get(LoadStoreOp);
unsigned NumRegs = EltSize / 4;
Register SubReg = e == 1
? ValueReg
: Register(getSubReg(ValueReg,
getSubRegFromChannel(RegOffset / 4, NumRegs)));
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);
}
// Make sure the whole register is defined if there are undef components by
// adding an implicit def of the super-reg on the first instruction.
bool NeedSuperRegDef = e > 1 && IsStore && i == 0;
bool NeedSuperRegImpOperand = e > 1;
// Remaining element size to spill into memory after some parts of it
// spilled into either AGPRs or VGPRs.
unsigned RemEltSize = EltSize;
// AGPRs to spill VGPRs and vice versa are allocated in a reverse order,
// starting from the last lane. In case if a register cannot be completely
// spilled into another register that will ensure its alignment does not
// change. For targets with VGPR alignment requirement this is important
// in case of flat scratch usage as we might get a scratch_load or
// scratch_store of an unaligned register otherwise.
for (int LaneS = (RegOffset + EltSize) / 4 - 1, Lane = LaneS,
LaneE = RegOffset / 4;
Lane >= LaneE; --Lane) {
bool IsSubReg = e > 1 || EltSize > 4;
Register Sub = IsSubReg
? Register(getSubReg(ValueReg, getSubRegFromChannel(Lane)))
: ValueReg;
auto MIB = spillVGPRtoAGPR(ST, MBB, MI, Index, Lane, Sub, IsKill);
if (!MIB.getInstr())
break;
if (NeedSuperRegDef || (IsSubReg && IsStore && Lane == LaneS && !i)) {
MIB.addReg(ValueReg, RegState::ImplicitDefine);
NeedSuperRegDef = false;
}
if (IsSubReg || NeedSuperRegImpOperand) {
NeedSuperRegImpOperand = true;
unsigned State = SrcDstRegState;
if (Lane != LaneE)
State &= ~RegState::Kill;
MIB.addReg(ValueReg, RegState::Implicit | State);
}
RemEltSize -= 4;
}
if (!RemEltSize) // Fully spilled into AGPRs.
continue;
if (RemEltSize != EltSize) { // Partially spilled to AGPRs
assert(IsFlat && EltSize > 4);
unsigned NumRegs = RemEltSize / 4;
SubReg = Register(getSubReg(ValueReg,
getSubRegFromChannel(RegOffset / 4, NumRegs)));
unsigned Opc = getFlatScratchSpillOpcode(TII, LoadStoreOp, RemEltSize);
Desc = &TII->get(Opc);
}
unsigned FinalReg = SubReg;
if (IsAGPR) {
assert(EltSize == 4);
if (!TmpReg) {
assert(RS && "Needs to have RegScavenger to spill an AGPR!");
// FIXME: change to scavengeRegisterBackwards()
TmpReg = RS->scavengeRegister(&AMDGPU::VGPR_32RegClass, MI, 0);
RS->setRegUsed(TmpReg);
}
if (IsStore) {
auto AccRead = BuildMI(MBB, MI, DL,
TII->get(AMDGPU::V_ACCVGPR_READ_B32_e64), TmpReg)
.addReg(SubReg, getKillRegState(IsKill));
if (NeedSuperRegDef)
AccRead.addReg(ValueReg, RegState::ImplicitDefine);
AccRead->setAsmPrinterFlag(MachineInstr::ReloadReuse);
}
SubReg = TmpReg;
}
MachinePointerInfo PInfo = BasePtrInfo.getWithOffset(RegOffset);
MachineMemOperand *NewMMO =
MF->getMachineMemOperand(PInfo, MMO->getFlags(), RemEltSize,
commonAlignment(Alignment, RegOffset));
auto MIB =
BuildMI(MBB, MI, DL, *Desc)
.addReg(SubReg, getDefRegState(!IsStore) | getKillRegState(IsKill));
if (!IsFlat)
MIB.addReg(FuncInfo->getScratchRSrcReg());
if (SOffset == AMDGPU::NoRegister) {
if (!IsFlat)
MIB.addImm(0);
} else {
MIB.addReg(SOffset, SOffsetRegState);
}
MIB.addImm(Offset + RegOffset)
.addImm(0); // cpol
if (!IsFlat)
MIB.addImm(0) // tfe
.addImm(0); // swz
MIB.addMemOperand(NewMMO);
if (!IsAGPR && NeedSuperRegDef)
MIB.addReg(ValueReg, RegState::ImplicitDefine);
if (!IsStore && TmpReg != AMDGPU::NoRegister) {
MIB = BuildMI(MBB, MI, DL, TII->get(AMDGPU::V_ACCVGPR_WRITE_B32_e64),
FinalReg)
.addReg(TmpReg, RegState::Kill);
MIB->setAsmPrinterFlag(MachineInstr::ReloadReuse);
}
if (NeedSuperRegImpOperand)
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_ADD_I32), SOffset)
.addReg(SOffset)
.addImm(-ScratchOffsetRegDelta);
}
}
void SIRegisterInfo::buildVGPRSpillLoadStore(SGPRSpillBuilder &SB, int Index,
int Offset, bool IsLoad,
bool IsKill) const {
// Load/store VGPR
MachineFrameInfo &FrameInfo = SB.MF.getFrameInfo();
assert(FrameInfo.getStackID(Index) != TargetStackID::SGPRSpill);
Register FrameReg =
FrameInfo.isFixedObjectIndex(Index) && hasBasePointer(SB.MF)
? getBaseRegister()
: getFrameRegister(SB.MF);
Align Alignment = FrameInfo.getObjectAlign(Index);
MachinePointerInfo PtrInfo = MachinePointerInfo::getFixedStack(SB.MF, Index);
MachineMemOperand *MMO = SB.MF.getMachineMemOperand(
PtrInfo, IsLoad ? MachineMemOperand::MOLoad : MachineMemOperand::MOStore,
SB.EltSize, Alignment);
if (IsLoad) {
unsigned Opc = ST.enableFlatScratch() ? AMDGPU::SCRATCH_LOAD_DWORD_SADDR
: AMDGPU::BUFFER_LOAD_DWORD_OFFSET;
buildSpillLoadStore(*SB.MBB, SB.MI, SB.DL, Opc, Index, SB.TmpVGPR, false,
FrameReg, Offset * SB.EltSize, MMO, SB.RS);
} else {
unsigned Opc = ST.enableFlatScratch() ? AMDGPU::SCRATCH_STORE_DWORD_SADDR
: AMDGPU::BUFFER_STORE_DWORD_OFFSET;
buildSpillLoadStore(*SB.MBB, SB.MI, SB.DL, Opc, Index, SB.TmpVGPR, IsKill,
FrameReg, Offset * SB.EltSize, MMO, SB.RS);
// This only ever adds one VGPR spill
SB.MFI.addToSpilledVGPRs(1);
}
}
bool SIRegisterInfo::spillSGPR(MachineBasicBlock::iterator MI,
int Index,
RegScavenger *RS,
LiveIntervals *LIS,
bool OnlyToVGPR) const {
SGPRSpillBuilder SB(*this, *ST.getInstrInfo(), isWave32, MI, Index, RS);
ArrayRef<SIMachineFunctionInfo::SpilledReg> VGPRSpills =
SB.MFI.getSGPRToVGPRSpills(Index);
bool SpillToVGPR = !VGPRSpills.empty();
if (OnlyToVGPR && !SpillToVGPR)
return false;
assert(SpillToVGPR || (SB.SuperReg != SB.MFI.getStackPtrOffsetReg() &&
SB.SuperReg != SB.MFI.getFrameOffsetReg()));
if (SpillToVGPR) {
assert(SB.NumSubRegs == VGPRSpills.size() &&
"Num of VGPR lanes should be equal to num of SGPRs spilled");
for (unsigned i = 0, e = SB.NumSubRegs; i < e; ++i) {
Register SubReg =
SB.NumSubRegs == 1
? SB.SuperReg
: Register(getSubReg(SB.SuperReg, SB.SplitParts[i]));
SIMachineFunctionInfo::SpilledReg Spill = VGPRSpills[i];
bool UseKill = SB.IsKill && i == SB.NumSubRegs - 1;
// 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.
auto MIB = BuildMI(*SB.MBB, MI, SB.DL,
SB.TII.get(AMDGPU::V_WRITELANE_B32), Spill.VGPR)
.addReg(SubReg, getKillRegState(UseKill))
.addImm(Spill.Lane)
.addReg(Spill.VGPR);
if (LIS) {
if (i == 0)
LIS->ReplaceMachineInstrInMaps(*MI, *MIB);
else
LIS->InsertMachineInstrInMaps(*MIB);
}
if (i == 0 && SB.NumSubRegs > 1) {
// We may be spilling a super-register which is only partially defined,
// and need to ensure later spills think the value is defined.
MIB.addReg(SB.SuperReg, RegState::ImplicitDefine);
}
if (SB.NumSubRegs > 1)
MIB.addReg(SB.SuperReg, getKillRegState(UseKill) | RegState::Implicit);
// 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 {
SB.prepare();
// SubReg carries the "Kill" flag when SubReg == SB.SuperReg.
unsigned SubKillState = getKillRegState((SB.NumSubRegs == 1) && SB.IsKill);
// Per VGPR helper data
auto PVD = SB.getPerVGPRData();
for (unsigned Offset = 0; Offset < PVD.NumVGPRs; ++Offset) {
unsigned TmpVGPRFlags = RegState::Undef;
// Write sub registers into the VGPR
for (unsigned i = Offset * PVD.PerVGPR,
e = std::min((Offset + 1) * PVD.PerVGPR, SB.NumSubRegs);
i < e; ++i) {
Register SubReg =
SB.NumSubRegs == 1
? SB.SuperReg
: Register(getSubReg(SB.SuperReg, SB.SplitParts[i]));
MachineInstrBuilder WriteLane =
BuildMI(*SB.MBB, MI, SB.DL, SB.TII.get(AMDGPU::V_WRITELANE_B32),
SB.TmpVGPR)
.addReg(SubReg, SubKillState)
.addImm(i % PVD.PerVGPR)
.addReg(SB.TmpVGPR, TmpVGPRFlags);
TmpVGPRFlags = 0;
if (LIS) {
if (i == 0)
LIS->ReplaceMachineInstrInMaps(*MI, *WriteLane);
else
LIS->InsertMachineInstrInMaps(*WriteLane);
}
// There could be undef components of a spilled super register.
// TODO: Can we detect this and skip the spill?
if (SB.NumSubRegs > 1) {
// The last implicit use of the SB.SuperReg carries the "Kill" flag.
unsigned SuperKillState = 0;
if (i + 1 == SB.NumSubRegs)
SuperKillState |= getKillRegState(SB.IsKill);
WriteLane.addReg(SB.SuperReg, RegState::Implicit | SuperKillState);
}
}
// Write out VGPR
SB.readWriteTmpVGPR(Offset, /*IsLoad*/ false);
}
SB.restore();
}
MI->eraseFromParent();
SB.MFI.addToSpilledSGPRs(SB.NumSubRegs);
if (LIS)
LIS->removeAllRegUnitsForPhysReg(SB.SuperReg);
return true;
}
bool SIRegisterInfo::restoreSGPR(MachineBasicBlock::iterator MI,
int Index,
RegScavenger *RS,
LiveIntervals *LIS,
bool OnlyToVGPR) const {
SGPRSpillBuilder SB(*this, *ST.getInstrInfo(), isWave32, MI, Index, RS);
ArrayRef<SIMachineFunctionInfo::SpilledReg> VGPRSpills =
SB.MFI.getSGPRToVGPRSpills(Index);
bool SpillToVGPR = !VGPRSpills.empty();
if (OnlyToVGPR && !SpillToVGPR)
return false;
if (SpillToVGPR) {
for (unsigned i = 0, e = SB.NumSubRegs; i < e; ++i) {
Register SubReg =
SB.NumSubRegs == 1
? SB.SuperReg
: Register(getSubReg(SB.SuperReg, SB.SplitParts[i]));
SIMachineFunctionInfo::SpilledReg Spill = VGPRSpills[i];
auto MIB = BuildMI(*SB.MBB, MI, SB.DL, SB.TII.get(AMDGPU::V_READLANE_B32),
SubReg)
.addReg(Spill.VGPR)
.addImm(Spill.Lane);
if (SB.NumSubRegs > 1 && i == 0)
MIB.addReg(SB.SuperReg, RegState::ImplicitDefine);
if (LIS) {
if (i == e - 1)
LIS->ReplaceMachineInstrInMaps(*MI, *MIB);
else
LIS->InsertMachineInstrInMaps(*MIB);
}
}
} else {
SB.prepare();
// Per VGPR helper data
auto PVD = SB.getPerVGPRData();
for (unsigned Offset = 0; Offset < PVD.NumVGPRs; ++Offset) {
// Load in VGPR data
SB.readWriteTmpVGPR(Offset, /*IsLoad*/ true);
// Unpack lanes
for (unsigned i = Offset * PVD.PerVGPR,
e = std::min((Offset + 1) * PVD.PerVGPR, SB.NumSubRegs);
i < e; ++i) {
Register SubReg =
SB.NumSubRegs == 1
? SB.SuperReg
: Register(getSubReg(SB.SuperReg, SB.SplitParts[i]));
bool LastSubReg = (i + 1 == e);
auto MIB = BuildMI(*SB.MBB, MI, SB.DL,
SB.TII.get(AMDGPU::V_READLANE_B32), SubReg)
.addReg(SB.TmpVGPR, getKillRegState(LastSubReg))
.addImm(i);
if (SB.NumSubRegs > 1 && i == 0)
MIB.addReg(SB.SuperReg, RegState::ImplicitDefine);
if (LIS) {
if (i == e - 1)
LIS->ReplaceMachineInstrInMaps(*MI, *MIB);
else
LIS->InsertMachineInstrInMaps(*MIB);
}
}
}
SB.restore();
}
MI->eraseFromParent();
if (LIS)
LIS->removeAllRegUnitsForPhysReg(SB.SuperReg);
return true;
}
bool SIRegisterInfo::spillEmergencySGPR(MachineBasicBlock::iterator MI,
MachineBasicBlock &RestoreMBB,
Register SGPR, RegScavenger *RS) const {
SGPRSpillBuilder SB(*this, *ST.getInstrInfo(), isWave32, MI, SGPR, false, 0,
RS);
SB.prepare();
// Generate the spill of SGPR to SB.TmpVGPR.
unsigned SubKillState = getKillRegState((SB.NumSubRegs == 1) && SB.IsKill);
auto PVD = SB.getPerVGPRData();
for (unsigned Offset = 0; Offset < PVD.NumVGPRs; ++Offset) {
unsigned TmpVGPRFlags = RegState::Undef;
// Write sub registers into the VGPR
for (unsigned i = Offset * PVD.PerVGPR,
e = std::min((Offset + 1) * PVD.PerVGPR, SB.NumSubRegs);
i < e; ++i) {
Register SubReg =
SB.NumSubRegs == 1
? SB.SuperReg
: Register(getSubReg(SB.SuperReg, SB.SplitParts[i]));
MachineInstrBuilder WriteLane =
BuildMI(*SB.MBB, MI, SB.DL, SB.TII.get(AMDGPU::V_WRITELANE_B32),
SB.TmpVGPR)
.addReg(SubReg, SubKillState)
.addImm(i % PVD.PerVGPR)
.addReg(SB.TmpVGPR, TmpVGPRFlags);
TmpVGPRFlags = 0;
// There could be undef components of a spilled super register.
// TODO: Can we detect this and skip the spill?
if (SB.NumSubRegs > 1) {
// The last implicit use of the SB.SuperReg carries the "Kill" flag.
unsigned SuperKillState = 0;
if (i + 1 == SB.NumSubRegs)
SuperKillState |= getKillRegState(SB.IsKill);
WriteLane.addReg(SB.SuperReg, RegState::Implicit | SuperKillState);
}
}
// Don't need to write VGPR out.
}
// Restore clobbered registers in the specified restore block.
MI = RestoreMBB.end();
SB.setMI(&RestoreMBB, MI);
// Generate the restore of SGPR from SB.TmpVGPR.
for (unsigned Offset = 0; Offset < PVD.NumVGPRs; ++Offset) {
// Don't need to load VGPR in.
// Unpack lanes
for (unsigned i = Offset * PVD.PerVGPR,
e = std::min((Offset + 1) * PVD.PerVGPR, SB.NumSubRegs);
i < e; ++i) {
Register SubReg =
SB.NumSubRegs == 1
? SB.SuperReg
: Register(getSubReg(SB.SuperReg, SB.SplitParts[i]));
bool LastSubReg = (i + 1 == e);
auto MIB = BuildMI(*SB.MBB, MI, SB.DL, SB.TII.get(AMDGPU::V_READLANE_B32),
SubReg)
.addReg(SB.TmpVGPR, getKillRegState(LastSubReg))
.addImm(i);
if (SB.NumSubRegs > 1 && i == 0)
MIB.addReg(SB.SuperReg, RegState::ImplicitDefine);
}
}
SB.restore();
SB.MFI.addToSpilledSGPRs(SB.NumSubRegs);
return false;
}
/// 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,
LiveIntervals *LIS) const {
switch (MI->getOpcode()) {
case AMDGPU::SI_SPILL_S1024_SAVE:
case AMDGPU::SI_SPILL_S512_SAVE:
case AMDGPU::SI_SPILL_S256_SAVE:
case AMDGPU::SI_SPILL_S224_SAVE:
case AMDGPU::SI_SPILL_S192_SAVE:
case AMDGPU::SI_SPILL_S160_SAVE:
case AMDGPU::SI_SPILL_S128_SAVE:
case AMDGPU::SI_SPILL_S96_SAVE:
case AMDGPU::SI_SPILL_S64_SAVE:
case AMDGPU::SI_SPILL_S32_SAVE:
return spillSGPR(MI, FI, RS, LIS, true);
case AMDGPU::SI_SPILL_S1024_RESTORE:
case AMDGPU::SI_SPILL_S512_RESTORE:
case AMDGPU::SI_SPILL_S256_RESTORE:
case AMDGPU::SI_SPILL_S224_RESTORE:
case AMDGPU::SI_SPILL_S192_RESTORE:
case AMDGPU::SI_SPILL_S160_RESTORE:
case AMDGPU::SI_SPILL_S128_RESTORE:
case AMDGPU::SI_SPILL_S96_RESTORE:
case AMDGPU::SI_SPILL_S64_RESTORE:
case AMDGPU::SI_SPILL_S32_RESTORE:
return restoreSGPR(MI, FI, RS, LIS, 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();
MachineBasicBlock *MBB = MI->getParent();
SIMachineFunctionInfo *MFI = MF->getInfo<SIMachineFunctionInfo>();
MachineFrameInfo &FrameInfo = MF->getFrameInfo();
const SIInstrInfo *TII = ST.getInstrInfo();
DebugLoc DL = MI->getDebugLoc();
assert(SPAdj == 0 && "unhandled SP adjustment in call sequence?");
MachineOperand &FIOp = MI->getOperand(FIOperandNum);
int Index = MI->getOperand(FIOperandNum).getIndex();
Register FrameReg = FrameInfo.isFixedObjectIndex(Index) && hasBasePointer(*MF)
? getBaseRegister()
: getFrameRegister(*MF);
switch (MI->getOpcode()) {
// SGPR register spill
case AMDGPU::SI_SPILL_S1024_SAVE:
case AMDGPU::SI_SPILL_S512_SAVE:
case AMDGPU::SI_SPILL_S256_SAVE:
case AMDGPU::SI_SPILL_S224_SAVE:
case AMDGPU::SI_SPILL_S192_SAVE:
case AMDGPU::SI_SPILL_S160_SAVE:
case AMDGPU::SI_SPILL_S128_SAVE:
case AMDGPU::SI_SPILL_S96_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_S1024_RESTORE:
case AMDGPU::SI_SPILL_S512_RESTORE:
case AMDGPU::SI_SPILL_S256_RESTORE:
case AMDGPU::SI_SPILL_S224_RESTORE:
case AMDGPU::SI_SPILL_S192_RESTORE:
case AMDGPU::SI_SPILL_S160_RESTORE:
case AMDGPU::SI_SPILL_S128_RESTORE:
case AMDGPU::SI_SPILL_S96_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_V1024_SAVE:
case AMDGPU::SI_SPILL_V512_SAVE:
case AMDGPU::SI_SPILL_V256_SAVE:
case AMDGPU::SI_SPILL_V224_SAVE:
case AMDGPU::SI_SPILL_V192_SAVE:
case AMDGPU::SI_SPILL_V160_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:
case AMDGPU::SI_SPILL_A1024_SAVE:
case AMDGPU::SI_SPILL_A512_SAVE:
case AMDGPU::SI_SPILL_A256_SAVE:
case AMDGPU::SI_SPILL_A224_SAVE:
case AMDGPU::SI_SPILL_A192_SAVE:
case AMDGPU::SI_SPILL_A160_SAVE:
case AMDGPU::SI_SPILL_A128_SAVE:
case AMDGPU::SI_SPILL_A96_SAVE:
case AMDGPU::SI_SPILL_A64_SAVE:
case AMDGPU::SI_SPILL_A32_SAVE: {
const MachineOperand *VData = TII->getNamedOperand(*MI,
AMDGPU::OpName::vdata);
assert(TII->getNamedOperand(*MI, AMDGPU::OpName::soffset)->getReg() ==
MFI->getStackPtrOffsetReg());
unsigned Opc = ST.enableFlatScratch() ? AMDGPU::SCRATCH_STORE_DWORD_SADDR
: AMDGPU::BUFFER_STORE_DWORD_OFFSET;
auto *MBB = MI->getParent();
buildSpillLoadStore(
*MBB, MI, DL, Opc, Index, VData->getReg(), VData->isKill(), FrameReg,
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_V160_RESTORE:
case AMDGPU::SI_SPILL_V192_RESTORE:
case AMDGPU::SI_SPILL_V224_RESTORE:
case AMDGPU::SI_SPILL_V256_RESTORE:
case AMDGPU::SI_SPILL_V512_RESTORE:
case AMDGPU::SI_SPILL_V1024_RESTORE:
case AMDGPU::SI_SPILL_A32_RESTORE:
case AMDGPU::SI_SPILL_A64_RESTORE:
case AMDGPU::SI_SPILL_A96_RESTORE:
case AMDGPU::SI_SPILL_A128_RESTORE:
case AMDGPU::SI_SPILL_A160_RESTORE:
case AMDGPU::SI_SPILL_A192_RESTORE:
case AMDGPU::SI_SPILL_A224_RESTORE:
case AMDGPU::SI_SPILL_A256_RESTORE:
case AMDGPU::SI_SPILL_A512_RESTORE:
case AMDGPU::SI_SPILL_A1024_RESTORE: {
const MachineOperand *VData = TII->getNamedOperand(*MI,
AMDGPU::OpName::vdata);
assert(TII->getNamedOperand(*MI, AMDGPU::OpName::soffset)->getReg() ==
MFI->getStackPtrOffsetReg());
unsigned Opc = ST.enableFlatScratch() ? AMDGPU::SCRATCH_LOAD_DWORD_SADDR
: AMDGPU::BUFFER_LOAD_DWORD_OFFSET;
auto *MBB = MI->getParent();
buildSpillLoadStore(
*MBB, MI, DL, Opc, Index, VData->getReg(), VData->isKill(), FrameReg,
TII->getNamedOperand(*MI, AMDGPU::OpName::offset)->getImm(),
*MI->memoperands_begin(), RS);
MI->eraseFromParent();
break;
}
default: {
// Other access to frame index
const DebugLoc &DL = MI->getDebugLoc();
int64_t Offset = FrameInfo.getObjectOffset(Index);
if (ST.enableFlatScratch()) {
if (TII->isFLATScratch(*MI)) {
assert((int16_t)FIOperandNum ==
AMDGPU::getNamedOperandIdx(MI->getOpcode(),
AMDGPU::OpName::saddr));
// The offset is always swizzled, just replace it
if (FrameReg)
FIOp.ChangeToRegister(FrameReg, false);
if (!Offset)
return;
MachineOperand *OffsetOp =
TII->getNamedOperand(*MI, AMDGPU::OpName::offset);
int64_t NewOffset = Offset + OffsetOp->getImm();
if (TII->isLegalFLATOffset(NewOffset, AMDGPUAS::PRIVATE_ADDRESS,
SIInstrFlags::FlatScratch)) {
OffsetOp->setImm(NewOffset);
if (FrameReg)
return;
Offset = 0;
}
assert(!TII->getNamedOperand(*MI, AMDGPU::OpName::vaddr) &&
"Unexpected vaddr for flat scratch with a FI operand");
// On GFX10 we have ST mode to use no registers for an address.
// Otherwise we need to materialize 0 into an SGPR.
if (!Offset && ST.hasFlatScratchSTMode()) {
unsigned Opc = MI->getOpcode();
unsigned NewOpc = AMDGPU::getFlatScratchInstSTfromSS(Opc);
MI->RemoveOperand(
AMDGPU::getNamedOperandIdx(Opc, AMDGPU::OpName::saddr));
MI->setDesc(TII->get(NewOpc));
return;
}
}
if (!FrameReg) {
FIOp.ChangeToImmediate(Offset);
if (TII->isImmOperandLegal(*MI, FIOperandNum, FIOp))
return;
}
// We need to use register here. Check if we can use an SGPR or need
// a VGPR.
FIOp.ChangeToRegister(AMDGPU::M0, false);
bool UseSGPR = TII->isOperandLegal(*MI, FIOperandNum, &FIOp);
if (!Offset && FrameReg && UseSGPR) {
FIOp.setReg(FrameReg);
return;
}
const TargetRegisterClass *RC = UseSGPR ? &AMDGPU::SReg_32_XM0RegClass
: &AMDGPU::VGPR_32RegClass;
Register TmpReg = RS->scavengeRegister(RC, MI, 0, !UseSGPR);
FIOp.setReg(TmpReg);
FIOp.setIsKill(true);
if ((!FrameReg || !Offset) && TmpReg) {
unsigned Opc = UseSGPR ? AMDGPU::S_MOV_B32 : AMDGPU::V_MOV_B32_e32;
auto MIB = BuildMI(*MBB, MI, DL, TII->get(Opc), TmpReg);
if (FrameReg)
MIB.addReg(FrameReg);
else
MIB.addImm(Offset);
return;
}
Register TmpSReg =
UseSGPR ? TmpReg
: RS->scavengeRegister(&AMDGPU::SReg_32_XM0RegClass, MI, 0,
!UseSGPR);
// TODO: for flat scratch another attempt can be made with a VGPR index
// if no SGPRs can be scavenged.
if ((!TmpSReg && !FrameReg) || (!TmpReg && !UseSGPR))
report_fatal_error("Cannot scavenge register in FI elimination!");
if (!TmpSReg) {
// Use frame register and restore it after.
TmpSReg = FrameReg;
FIOp.setReg(FrameReg);
FIOp.setIsKill(false);
}
BuildMI(*MBB, MI, DL, TII->get(AMDGPU::S_ADD_I32), TmpSReg)
.addReg(FrameReg)
.addImm(Offset);
if (!UseSGPR)
BuildMI(*MBB, MI, DL, TII->get(AMDGPU::V_MOV_B32_e32), TmpReg)
.addReg(TmpSReg, RegState::Kill);
if (TmpSReg == FrameReg) {
// Undo frame register modification.
BuildMI(*MBB, std::next(MI), DL, TII->get(AMDGPU::S_ADD_I32),
FrameReg)
.addReg(FrameReg)
.addImm(-Offset);
}
return;
}
bool IsMUBUF = TII->isMUBUF(*MI);
if (!IsMUBUF && !MFI->isEntryFunction()) {
// Convert to a swizzled stack address by scaling by the wave size.
//
// In an entry function/kernel the offset is already swizzled.
bool IsCopy = MI->getOpcode() == AMDGPU::V_MOV_B32_e32;
Register ResultReg =
IsCopy ? MI->getOperand(0).getReg()
: RS->scavengeRegister(&AMDGPU::VGPR_32RegClass, MI, 0);
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(ST.getWavefrontSizeLog2())
.addReg(FrameReg);
} else {
if (auto MIB = TII->getAddNoCarry(*MBB, MI, DL, ResultReg, *RS)) {
// Reuse ResultReg in intermediate step.
Register ScaledReg = ResultReg;
BuildMI(*MBB, *MIB, DL, TII->get(AMDGPU::V_LSHRREV_B32_e64),
ScaledReg)
.addImm(ST.getWavefrontSizeLog2())
.addReg(FrameReg);
const bool IsVOP2 = MIB->getOpcode() == AMDGPU::V_ADD_U32_e32;
// TODO: Fold if use instruction is another add of a constant.
if (IsVOP2 || AMDGPU::isInlinableLiteral32(Offset, ST.hasInv2PiInlineImm())) {
// FIXME: This can fail
MIB.addImm(Offset);
MIB.addReg(ScaledReg, RegState::Kill);
if (!IsVOP2)
MIB.addImm(0); // clamp bit
} else {
assert(MIB->getOpcode() == AMDGPU::V_ADD_CO_U32_e64 &&
"Need to reuse carry out register");
// Use scavenged unused carry out as offset register.
Register ConstOffsetReg;
if (!isWave32)
ConstOffsetReg = getSubReg(MIB.getReg(1), AMDGPU::sub0);
else
ConstOffsetReg = MIB.getReg(1);
BuildMI(*MBB, *MIB, DL, TII->get(AMDGPU::S_MOV_B32), ConstOffsetReg)
.addImm(Offset);
MIB.addReg(ConstOffsetReg, RegState::Kill);
MIB.addReg(ScaledReg, RegState::Kill);
MIB.addImm(0); // clamp bit
}
} else {
// We have to produce a carry out, and there isn't a free SGPR pair
// for it. We can keep the whole computation on the SALU to avoid
// clobbering an additional register at the cost of an extra mov.
// We may have 1 free scratch SGPR even though a carry out is
// unavailable. Only one additional mov is needed.
Register TmpScaledReg =
RS->scavengeRegister(&AMDGPU::SReg_32_XM0RegClass, MI, 0, false);
Register ScaledReg = TmpScaledReg.isValid() ? TmpScaledReg : FrameReg;
BuildMI(*MBB, MI, DL, TII->get(AMDGPU::S_LSHR_B32), ScaledReg)
.addReg(FrameReg)
.addImm(ST.getWavefrontSizeLog2());
BuildMI(*MBB, MI, DL, TII->get(AMDGPU::S_ADD_I32), ScaledReg)
.addReg(ScaledReg, RegState::Kill)
.addImm(Offset);
BuildMI(*MBB, MI, DL, TII->get(AMDGPU::COPY), ResultReg)
.addReg(ScaledReg, RegState::Kill);
// If there were truly no free SGPRs, we need to undo everything.
if (!TmpScaledReg.isValid()) {
BuildMI(*MBB, MI, DL, TII->get(AMDGPU::S_ADD_I32), ScaledReg)
.addReg(ScaledReg, RegState::Kill)
.addImm(-Offset);
BuildMI(*MBB, MI, DL, TII->get(AMDGPU::S_LSHL_B32), ScaledReg)
.addReg(FrameReg)
.addImm(ST.getWavefrontSizeLog2());
}
}
}
// 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));
auto &SOffset = *TII->getNamedOperand(*MI, AMDGPU::OpName::soffset);
assert((SOffset.isImm() && SOffset.getImm() == 0));
if (FrameReg != AMDGPU::NoRegister)
SOffset.ChangeToRegister(FrameReg, false);
int64_t Offset = FrameInfo.getObjectOffset(Index);
int64_t OldImm
= TII->getNamedOperand(*MI, AMDGPU::OpName::offset)->getImm();
int64_t NewOffset = OldImm + Offset;
if (SIInstrInfo::isLegalMUBUFImmOffset(NewOffset) &&
buildMUBUFOffsetLoadStore(ST, FrameInfo, MI, Index, NewOffset)) {
MI->eraseFromParent();
return;
}
}
// If the offset is simply too big, don't convert to a scratch wave offset
// relative index.
FIOp.ChangeToImmediate(Offset);
if (!TII->isImmOperandLegal(*MI, FIOperandNum, FIOp)) {
Register TmpReg = RS->scavengeRegister(&AMDGPU::VGPR_32RegClass, MI, 0);
BuildMI(*MBB, MI, DL, TII->get(AMDGPU::V_MOV_B32_e32), TmpReg)
.addImm(Offset);
FIOp.ChangeToRegister(TmpReg, false, false, true);
}
}
}
}
StringRef SIRegisterInfo::getRegAsmName(MCRegister Reg) const {
return AMDGPUInstPrinter::getRegisterName(Reg);
}
static const TargetRegisterClass *
getAnyVGPRClassForBitWidth(unsigned BitWidth) {
if (BitWidth <= 64)
return &AMDGPU::VReg_64RegClass;
if (BitWidth <= 96)
return &AMDGPU::VReg_96RegClass;
if (BitWidth <= 128)
return &AMDGPU::VReg_128RegClass;
if (BitWidth <= 160)
return &AMDGPU::VReg_160RegClass;
if (BitWidth <= 192)
return &AMDGPU::VReg_192RegClass;
if (BitWidth <= 224)
return &AMDGPU::VReg_224RegClass;
if (BitWidth <= 256)
return &AMDGPU::VReg_256RegClass;
if (BitWidth <= 512)
return &AMDGPU::VReg_512RegClass;
if (BitWidth <= 1024)
return &AMDGPU::VReg_1024RegClass;
return nullptr;
}
static const TargetRegisterClass *
getAlignedVGPRClassForBitWidth(unsigned BitWidth) {
if (BitWidth <= 64)
return &AMDGPU::VReg_64_Align2RegClass;
if (BitWidth <= 96)
return &AMDGPU::VReg_96_Align2RegClass;
if (BitWidth <= 128)
return &AMDGPU::VReg_128_Align2RegClass;
if (BitWidth <= 160)
return &AMDGPU::VReg_160_Align2RegClass;
if (BitWidth <= 192)
return &AMDGPU::VReg_192_Align2RegClass;
if (BitWidth <= 224)
return &AMDGPU::VReg_224_Align2RegClass;
if (BitWidth <= 256)
return &AMDGPU::VReg_256_Align2RegClass;
if (BitWidth <= 512)
return &AMDGPU::VReg_512_Align2RegClass;
if (BitWidth <= 1024)
return &AMDGPU::VReg_1024_Align2RegClass;
return nullptr;
}
const TargetRegisterClass *
SIRegisterInfo::getVGPRClassForBitWidth(unsigned BitWidth) const {
if (BitWidth == 1)
return &AMDGPU::VReg_1RegClass;
if (BitWidth <= 16)
return &AMDGPU::VGPR_LO16RegClass;
if (BitWidth <= 32)
return &AMDGPU::VGPR_32RegClass;
return ST.needsAlignedVGPRs() ? getAlignedVGPRClassForBitWidth(BitWidth)
: getAnyVGPRClassForBitWidth(BitWidth);
}
static const TargetRegisterClass *
getAnyAGPRClassForBitWidth(unsigned BitWidth) {
if (BitWidth <= 64)
return &AMDGPU::AReg_64RegClass;
if (BitWidth <= 96)
return &AMDGPU::AReg_96RegClass;
if (BitWidth <= 128)
return &AMDGPU::AReg_128RegClass;
if (BitWidth <= 160)
return &AMDGPU::AReg_160RegClass;
if (BitWidth <= 192)
return &AMDGPU::AReg_192RegClass;
if (BitWidth <= 224)
return &AMDGPU::AReg_224RegClass;
if (BitWidth <= 256)
return &AMDGPU::AReg_256RegClass;
if (BitWidth <= 512)
return &AMDGPU::AReg_512RegClass;
if (BitWidth <= 1024)
return &AMDGPU::AReg_1024RegClass;
return nullptr;
}
static const TargetRegisterClass *
getAlignedAGPRClassForBitWidth(unsigned BitWidth) {
if (BitWidth <= 64)
return &AMDGPU::AReg_64_Align2RegClass;
if (BitWidth <= 96)
return &AMDGPU::AReg_96_Align2RegClass;
if (BitWidth <= 128)
return &AMDGPU::AReg_128_Align2RegClass;
if (BitWidth <= 160)
return &AMDGPU::AReg_160_Align2RegClass;
if (BitWidth <= 192)
return &AMDGPU::AReg_192_Align2RegClass;
if (BitWidth <= 224)
return &AMDGPU::AReg_224_Align2RegClass;
if (BitWidth <= 256)
return &AMDGPU::AReg_256_Align2RegClass;
if (BitWidth <= 512)
return &AMDGPU::AReg_512_Align2RegClass;
if (BitWidth <= 1024)
return &AMDGPU::AReg_1024_Align2RegClass;
return nullptr;
}
const TargetRegisterClass *
SIRegisterInfo::getAGPRClassForBitWidth(unsigned BitWidth) const {
if (BitWidth <= 16)
return &AMDGPU::AGPR_LO16RegClass;
if (BitWidth <= 32)
return &AMDGPU::AGPR_32RegClass;
return ST.needsAlignedVGPRs() ? getAlignedAGPRClassForBitWidth(BitWidth)
: getAnyAGPRClassForBitWidth(BitWidth);
}
static const TargetRegisterClass *
getAnyVectorSuperClassForBitWidth(unsigned BitWidth) {
if (BitWidth <= 64)
return &AMDGPU::AV_64RegClass;
if (BitWidth <= 96)
return &AMDGPU::AV_96RegClass;
if (BitWidth <= 128)
return &AMDGPU::AV_128RegClass;
if (BitWidth <= 160)
return &AMDGPU::AV_160RegClass;
if (BitWidth <= 192)
return &AMDGPU::AV_192RegClass;
if (BitWidth <= 224)
return &AMDGPU::AV_224RegClass;
if (BitWidth <= 256)
return &AMDGPU::AV_256RegClass;
if (BitWidth <= 512)
return &AMDGPU::AV_512RegClass;
if (BitWidth <= 1024)
return &AMDGPU::AV_1024RegClass;
return nullptr;
}
static const TargetRegisterClass *
getAlignedVectorSuperClassForBitWidth(unsigned BitWidth) {
if (BitWidth <= 64)
return &AMDGPU::AV_64_Align2RegClass;
if (BitWidth <= 96)
return &AMDGPU::AV_96_Align2RegClass;
if (BitWidth <= 128)
return &AMDGPU::AV_128_Align2RegClass;
if (BitWidth <= 160)
return &AMDGPU::AV_160_Align2RegClass;
if (BitWidth <= 192)
return &AMDGPU::AV_192_Align2RegClass;
if (BitWidth <= 224)
return &AMDGPU::AV_224_Align2RegClass;
if (BitWidth <= 256)
return &AMDGPU::AV_256_Align2RegClass;
if (BitWidth <= 512)
return &AMDGPU::AV_512_Align2RegClass;
if (BitWidth <= 1024)
return &AMDGPU::AV_1024_Align2RegClass;
return nullptr;
}
const TargetRegisterClass *
SIRegisterInfo::getVectorSuperClassForBitWidth(unsigned BitWidth) const {
if (BitWidth <= 16)
return &AMDGPU::VGPR_LO16RegClass;
if (BitWidth <= 32)
return &AMDGPU::AV_32RegClass;
return ST.needsAlignedVGPRs()
? getAlignedVectorSuperClassForBitWidth(BitWidth)
: getAnyVectorSuperClassForBitWidth(BitWidth);
}
const TargetRegisterClass *
SIRegisterInfo::getSGPRClassForBitWidth(unsigned BitWidth) {
if (BitWidth <= 16)
return &AMDGPU::SGPR_LO16RegClass;
if (BitWidth <= 32)
return &AMDGPU::SReg_32RegClass;
if (BitWidth <= 64)
return &AMDGPU::SReg_64RegClass;
if (BitWidth <= 96)
return &AMDGPU::SGPR_96RegClass;
if (BitWidth <= 128)
return &AMDGPU::SGPR_128RegClass;
if (BitWidth <= 160)
return &AMDGPU::SGPR_160RegClass;
if (BitWidth <= 192)
return &AMDGPU::SGPR_192RegClass;
if (BitWidth <= 224)
return &AMDGPU::SGPR_224RegClass;
if (BitWidth <= 256)
return &AMDGPU::SGPR_256RegClass;
if (BitWidth <= 512)
return &AMDGPU::SGPR_512RegClass;
if (BitWidth <= 1024)
return &AMDGPU::SGPR_1024RegClass;
return nullptr;
}
// FIXME: This is very slow. It might be worth creating a map from physreg to
// register class.
const TargetRegisterClass *
SIRegisterInfo::getPhysRegClass(MCRegister Reg) const {
static const TargetRegisterClass *const BaseClasses[] = {
&AMDGPU::VGPR_LO16RegClass,
&AMDGPU::VGPR_HI16RegClass,
&AMDGPU::SReg_LO16RegClass,
&AMDGPU::AGPR_LO16RegClass,
&AMDGPU::VGPR_32RegClass,
&AMDGPU::SReg_32RegClass,
&AMDGPU::AGPR_32RegClass,
&AMDGPU::AGPR_32RegClass,
&AMDGPU::VReg_64_Align2RegClass,
&AMDGPU::VReg_64RegClass,
&AMDGPU::SReg_64RegClass,
&AMDGPU::AReg_64_Align2RegClass,
&AMDGPU::AReg_64RegClass,
&AMDGPU::VReg_96_Align2RegClass,
&AMDGPU::VReg_96RegClass,
&AMDGPU::SReg_96RegClass,
&AMDGPU::AReg_96_Align2RegClass,
&AMDGPU::AReg_96RegClass,
&AMDGPU::VReg_128_Align2RegClass,
&AMDGPU::VReg_128RegClass,
&AMDGPU::SReg_128RegClass,
&AMDGPU::AReg_128_Align2RegClass,
&AMDGPU::AReg_128RegClass,
&AMDGPU::VReg_160_Align2RegClass,
&AMDGPU::VReg_160RegClass,
&AMDGPU::SReg_160RegClass,
&AMDGPU::AReg_160_Align2RegClass,
&AMDGPU::AReg_160RegClass,
&AMDGPU::VReg_192_Align2RegClass,
&AMDGPU::VReg_192RegClass,
&AMDGPU::SReg_192RegClass,
&AMDGPU::AReg_192_Align2RegClass,
&AMDGPU::AReg_192RegClass,
&AMDGPU::VReg_224_Align2RegClass,
&AMDGPU::VReg_224RegClass,
&AMDGPU::SReg_224RegClass,
&AMDGPU::AReg_224_Align2RegClass,
&AMDGPU::AReg_224RegClass,
&AMDGPU::VReg_256_Align2RegClass,
&AMDGPU::VReg_256RegClass,
&AMDGPU::SReg_256RegClass,
&AMDGPU::AReg_256_Align2RegClass,
&AMDGPU::AReg_256RegClass,
&AMDGPU::VReg_512_Align2RegClass,
&AMDGPU::VReg_512RegClass,
&AMDGPU::SReg_512RegClass,
&AMDGPU::AReg_512_Align2RegClass,
&AMDGPU::AReg_512RegClass,
&AMDGPU::SReg_1024RegClass,
&AMDGPU::VReg_1024_Align2RegClass,
&AMDGPU::VReg_1024RegClass,
&AMDGPU::AReg_1024_Align2RegClass,
&AMDGPU::AReg_1024RegClass,
&AMDGPU::SCC_CLASSRegClass,
&AMDGPU::Pseudo_SReg_32RegClass,
&AMDGPU::Pseudo_SReg_128RegClass,
};
for (const TargetRegisterClass *BaseClass : BaseClasses) {
if (BaseClass->contains(Reg)) {
return BaseClass;
}
}
return nullptr;
}
bool SIRegisterInfo::isSGPRReg(const MachineRegisterInfo &MRI,
Register Reg) const {
const TargetRegisterClass *RC;
if (Reg.isVirtual())
RC = MRI.getRegClass(Reg);
else
RC = getPhysRegClass(Reg);
return isSGPRClass(RC);
}
const TargetRegisterClass *
SIRegisterInfo::getEquivalentVGPRClass(const TargetRegisterClass *SRC) const {
unsigned Size = getRegSizeInBits(*SRC);
const TargetRegisterClass *VRC = getVGPRClassForBitWidth(Size);
assert(VRC && "Invalid register class size");
return VRC;
}
const TargetRegisterClass *
SIRegisterInfo::getEquivalentAGPRClass(const TargetRegisterClass *SRC) const {
unsigned Size = getRegSizeInBits(*SRC);
const TargetRegisterClass *ARC = getAGPRClassForBitWidth(Size);
assert(ARC && "Invalid register class size");
return ARC;
}
const TargetRegisterClass *
SIRegisterInfo::getEquivalentSGPRClass(const TargetRegisterClass *VRC) const {
unsigned Size = getRegSizeInBits(*VRC);
if (Size == 32)
return &AMDGPU::SGPR_32RegClass;
const TargetRegisterClass *SRC = getSGPRClassForBitWidth(Size);
assert(SRC && "Invalid register class size");
return SRC;
}
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 Size = getNumChannelsFromSubReg(SubIdx) * 32;
if (isAGPRClass(RC)) {
RC = getAGPRClassForBitWidth(Size);
} else if (isVGPRClass(RC)) {
RC = getVGPRClassForBitWidth(Size);
} else if (isVectorSuperClass(RC)) {
RC = getVectorSuperClassForBitWidth(Size);
} else {
RC = getSGPRClassForBitWidth(Size);
}
assert(RC && "Invalid sub-register class size");
return RC;
}
const TargetRegisterClass *
SIRegisterInfo::getCompatibleSubRegClass(const TargetRegisterClass *SuperRC,
const TargetRegisterClass *SubRC,
unsigned SubIdx) const {
// Ensure this subregister index is aligned in the super register.
const TargetRegisterClass *MatchRC =
getMatchingSuperRegClass(SuperRC, SubRC, SubIdx);
return MatchRC && MatchRC->hasSubClassEq(SuperRC) ? MatchRC : nullptr;
}
bool SIRegisterInfo::opCanUseInlineConstant(unsigned OpType) const {
if (OpType >= AMDGPU::OPERAND_REG_INLINE_AC_FIRST &&
OpType <= AMDGPU::OPERAND_REG_INLINE_AC_LAST)
return !ST.hasMFMAInlineLiteralBug();
return OpType >= AMDGPU::OPERAND_SRC_FIRST &&
OpType <= AMDGPU::OPERAND_SRC_LAST;
}
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;
}
bool SIRegisterInfo::opCanUseLiteralConstant(unsigned OpType) const {
// TODO: 64-bit operands have extending behavior from 32-bit literal.
return OpType >= AMDGPU::OPERAND_REG_IMM_FIRST &&
OpType <= AMDGPU::OPERAND_REG_IMM_LAST;
}
/// Returns a lowest register that is not used at any point in the function.
/// If all registers are used, then this function will return
/// AMDGPU::NoRegister. If \p ReserveHighestVGPR = true, then return
/// highest unused register.
MCRegister SIRegisterInfo::findUnusedRegister(const MachineRegisterInfo &MRI,
const TargetRegisterClass *RC,
const MachineFunction &MF,
bool ReserveHighestVGPR) const {
if (ReserveHighestVGPR) {
for (MCRegister Reg : reverse(*RC))
if (MRI.isAllocatable(Reg) && !MRI.isPhysRegUsed(Reg))
return Reg;
} else {
for (MCRegister Reg : *RC)
if (MRI.isAllocatable(Reg) && !MRI.isPhysRegUsed(Reg))
return Reg;
}
return MCRegister();
}
ArrayRef<int16_t> SIRegisterInfo::getRegSplitParts(const TargetRegisterClass *RC,
unsigned EltSize) const {
const unsigned RegBitWidth = AMDGPU::getRegBitWidth(*RC->MC);
assert(RegBitWidth >= 32 && RegBitWidth <= 1024);
const unsigned RegDWORDs = RegBitWidth / 32;
const unsigned EltDWORDs = EltSize / 4;
assert(RegSplitParts.size() + 1 >= EltDWORDs);
const std::vector<int16_t> &Parts = RegSplitParts[EltDWORDs - 1];
const unsigned NumParts = RegDWORDs / EltDWORDs;
return makeArrayRef(Parts.data(), NumParts);
}
const TargetRegisterClass*
SIRegisterInfo::getRegClassForReg(const MachineRegisterInfo &MRI,
Register Reg) const {
return Reg.isVirtual() ? MRI.getRegClass(Reg) : getPhysRegClass(Reg);
}
bool SIRegisterInfo::isVGPR(const MachineRegisterInfo &MRI,
Register Reg) const {
const TargetRegisterClass *RC = getRegClassForReg(MRI, Reg);
// Registers without classes are unaddressable, SGPR-like registers.
return RC && isVGPRClass(RC);
}
bool SIRegisterInfo::isAGPR(const MachineRegisterInfo &MRI,
Register Reg) const {
const TargetRegisterClass *RC = getRegClassForReg(MRI, Reg);
// Registers without classes are unaddressable, SGPR-like registers.
return RC && isAGPRClass(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 SIMachineFunctionInfo *MFI = MF.getInfo<SIMachineFunctionInfo>();
unsigned Occupancy = ST.getOccupancyWithLocalMemSize(MFI->getLDSSize(),
MF.getFunction());
switch (RC->getID()) {
default:
return AMDGPUGenRegisterInfo::getRegPressureLimit(RC, MF);
case AMDGPU::VGPR_32RegClassID:
case AMDGPU::VGPR_LO16RegClassID:
case AMDGPU::VGPR_HI16RegClassID:
return std::min(ST.getMaxNumVGPRs(Occupancy), ST.getMaxNumVGPRs(MF));
case AMDGPU::SGPR_32RegClassID:
case AMDGPU::SGPR_LO16RegClassID:
return std::min(ST.getMaxNumSGPRs(Occupancy, true), ST.getMaxNumSGPRs(MF));
}
}
unsigned SIRegisterInfo::getRegPressureSetLimit(const MachineFunction &MF,
unsigned Idx) const {
if (Idx == AMDGPU::RegisterPressureSets::VGPR_32 ||
Idx == AMDGPU::RegisterPressureSets::AGPR_32)
return getRegPressureLimit(&AMDGPU::VGPR_32RegClass,
const_cast<MachineFunction &>(MF));
if (Idx == AMDGPU::RegisterPressureSets::SReg_32)
return getRegPressureLimit(&AMDGPU::SGPR_32RegClass,
const_cast<MachineFunction &>(MF));
llvm_unreachable("Unexpected register pressure set!");
}
const int *SIRegisterInfo::getRegUnitPressureSets(unsigned RegUnit) const {
static const int Empty[] = { -1 };
if (RegPressureIgnoredUnits[RegUnit])
return Empty;
return AMDGPUGenRegisterInfo::getRegUnitPressureSets(RegUnit);
}
MCRegister SIRegisterInfo::getReturnAddressReg(const MachineFunction &MF) const {
// Not a callee saved register.
return AMDGPU::SGPR30_SGPR31;
}