746 lines · cpp
1//===- StackMaps.cpp ------------------------------------------------------===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8 9#include "llvm/CodeGen/StackMaps.h"10#include "llvm/ADT/DenseMapInfo.h"11#include "llvm/ADT/STLExtras.h"12#include "llvm/ADT/Twine.h"13#include "llvm/CodeGen/AsmPrinter.h"14#include "llvm/CodeGen/MachineFrameInfo.h"15#include "llvm/CodeGen/MachineFunction.h"16#include "llvm/CodeGen/MachineInstr.h"17#include "llvm/CodeGen/MachineOperand.h"18#include "llvm/CodeGen/TargetOpcodes.h"19#include "llvm/CodeGen/TargetRegisterInfo.h"20#include "llvm/CodeGen/TargetSubtargetInfo.h"21#include "llvm/IR/DataLayout.h"22#include "llvm/MC/MCContext.h"23#include "llvm/MC/MCExpr.h"24#include "llvm/MC/MCObjectFileInfo.h"25#include "llvm/MC/MCStreamer.h"26#include "llvm/Support/CommandLine.h"27#include "llvm/Support/Debug.h"28#include "llvm/Support/ErrorHandling.h"29#include "llvm/Support/MathExtras.h"30#include "llvm/Support/raw_ostream.h"31#include <algorithm>32#include <cassert>33#include <cstdint>34#include <iterator>35#include <utility>36 37using namespace llvm;38 39#define DEBUG_TYPE "stackmaps"40 41static cl::opt<int> StackMapVersion(42 "stackmap-version", cl::init(3), cl::Hidden,43 cl::desc("Specify the stackmap encoding version (default = 3)"));44 45const char *StackMaps::WSMP = "Stack Maps: ";46 47static uint64_t getConstMetaVal(const MachineInstr &MI, unsigned Idx) {48 assert(MI.getOperand(Idx).isImm() &&49 MI.getOperand(Idx).getImm() == StackMaps::ConstantOp);50 const auto &MO = MI.getOperand(Idx + 1);51 assert(MO.isImm());52 return MO.getImm();53}54 55StackMapOpers::StackMapOpers(const MachineInstr *MI)56 : MI(MI) {57 assert(getVarIdx() <= MI->getNumOperands() &&58 "invalid stackmap definition");59}60 61PatchPointOpers::PatchPointOpers(const MachineInstr *MI)62 : MI(MI), HasDef(MI->getOperand(0).isReg() && MI->getOperand(0).isDef() &&63 !MI->getOperand(0).isImplicit()) {64#ifndef NDEBUG65 unsigned CheckStartIdx = 0, e = MI->getNumOperands();66 while (CheckStartIdx < e && MI->getOperand(CheckStartIdx).isReg() &&67 MI->getOperand(CheckStartIdx).isDef() &&68 !MI->getOperand(CheckStartIdx).isImplicit())69 ++CheckStartIdx;70 71 assert(getMetaIdx() == CheckStartIdx &&72 "Unexpected additional definition in Patchpoint intrinsic.");73#endif74}75 76unsigned PatchPointOpers::getNextScratchIdx(unsigned StartIdx) const {77 if (!StartIdx)78 StartIdx = getVarIdx();79 80 // Find the next scratch register (implicit def and early clobber)81 unsigned ScratchIdx = StartIdx, e = MI->getNumOperands();82 while (ScratchIdx < e &&83 !(MI->getOperand(ScratchIdx).isReg() &&84 MI->getOperand(ScratchIdx).isDef() &&85 MI->getOperand(ScratchIdx).isImplicit() &&86 MI->getOperand(ScratchIdx).isEarlyClobber()))87 ++ScratchIdx;88 89 assert(ScratchIdx != e && "No scratch register available");90 return ScratchIdx;91}92 93unsigned StatepointOpers::getNumGcMapEntriesIdx() {94 // Take index of num of allocas and skip all allocas records.95 unsigned CurIdx = getNumAllocaIdx();96 unsigned NumAllocas = getConstMetaVal(*MI, CurIdx - 1);97 CurIdx++;98 while (NumAllocas--)99 CurIdx = StackMaps::getNextMetaArgIdx(MI, CurIdx);100 return CurIdx + 1; // skip <StackMaps::ConstantOp>101}102 103unsigned StatepointOpers::getNumAllocaIdx() {104 // Take index of num of gc ptrs and skip all gc ptr records.105 unsigned CurIdx = getNumGCPtrIdx();106 unsigned NumGCPtrs = getConstMetaVal(*MI, CurIdx - 1);107 CurIdx++;108 while (NumGCPtrs--)109 CurIdx = StackMaps::getNextMetaArgIdx(MI, CurIdx);110 return CurIdx + 1; // skip <StackMaps::ConstantOp>111}112 113unsigned StatepointOpers::getNumGCPtrIdx() {114 // Take index of num of deopt args and skip all deopt records.115 unsigned CurIdx = getNumDeoptArgsIdx();116 unsigned NumDeoptArgs = getConstMetaVal(*MI, CurIdx - 1);117 CurIdx++;118 while (NumDeoptArgs--) {119 CurIdx = StackMaps::getNextMetaArgIdx(MI, CurIdx);120 }121 return CurIdx + 1; // skip <StackMaps::ConstantOp>122}123 124int StatepointOpers::getFirstGCPtrIdx() {125 unsigned NumGCPtrsIdx = getNumGCPtrIdx();126 unsigned NumGCPtrs = getConstMetaVal(*MI, NumGCPtrsIdx - 1);127 if (NumGCPtrs == 0)128 return -1;129 ++NumGCPtrsIdx; // skip <num gc ptrs>130 assert(NumGCPtrsIdx < MI->getNumOperands());131 return (int)NumGCPtrsIdx;132}133 134unsigned StatepointOpers::getGCPointerMap(135 SmallVectorImpl<std::pair<unsigned, unsigned>> &GCMap) {136 unsigned CurIdx = getNumGcMapEntriesIdx();137 unsigned GCMapSize = getConstMetaVal(*MI, CurIdx - 1);138 CurIdx++;139 for (unsigned N = 0; N < GCMapSize; ++N) {140 unsigned B = MI->getOperand(CurIdx++).getImm();141 unsigned D = MI->getOperand(CurIdx++).getImm();142 GCMap.push_back(std::make_pair(B, D));143 }144 145 return GCMapSize;146}147 148bool StatepointOpers::isFoldableReg(Register Reg) const {149 unsigned FoldableAreaStart = getVarIdx();150 for (const MachineOperand &MO : MI->uses()) {151 if (MO.getOperandNo() >= FoldableAreaStart)152 break;153 if (MO.isReg() && MO.getReg() == Reg)154 return false;155 }156 return true;157}158 159bool StatepointOpers::isFoldableReg(const MachineInstr *MI, Register Reg) {160 if (MI->getOpcode() != TargetOpcode::STATEPOINT)161 return false;162 return StatepointOpers(MI).isFoldableReg(Reg);163}164 165StackMaps::StackMaps(AsmPrinter &AP) : AP(AP) {166 if (StackMapVersion != 3)167 llvm_unreachable("Unsupported stackmap version!");168}169 170unsigned StackMaps::getNextMetaArgIdx(const MachineInstr *MI, unsigned CurIdx) {171 assert(CurIdx < MI->getNumOperands() && "Bad meta arg index");172 const auto &MO = MI->getOperand(CurIdx);173 if (MO.isImm()) {174 switch (MO.getImm()) {175 default:176 llvm_unreachable("Unrecognized operand type.");177 case StackMaps::DirectMemRefOp:178 CurIdx += 2;179 break;180 case StackMaps::IndirectMemRefOp:181 CurIdx += 3;182 break;183 case StackMaps::ConstantOp:184 ++CurIdx;185 break;186 }187 }188 ++CurIdx;189 assert(CurIdx < MI->getNumOperands() && "points past operand list");190 return CurIdx;191}192 193/// Go up the super-register chain until we hit a valid dwarf register number.194static unsigned getDwarfRegNum(MCRegister Reg, const TargetRegisterInfo *TRI) {195 int RegNum;196 for (MCPhysReg SR : TRI->superregs_inclusive(Reg)) {197 RegNum = TRI->getDwarfRegNum(SR, false);198 if (RegNum >= 0)199 break;200 }201 202 assert(RegNum >= 0 && isUInt<16>(RegNum) && "Invalid Dwarf register number.");203 return (unsigned)RegNum;204}205 206MachineInstr::const_mop_iterator207StackMaps::parseOperand(MachineInstr::const_mop_iterator MOI,208 MachineInstr::const_mop_iterator MOE, LocationVec &Locs,209 LiveOutVec &LiveOuts) {210 const TargetRegisterInfo *TRI = AP.MF->getSubtarget().getRegisterInfo();211 if (MOI->isImm()) {212 switch (MOI->getImm()) {213 default:214 llvm_unreachable("Unrecognized operand type.");215 case StackMaps::DirectMemRefOp: {216 auto &DL = AP.MF->getDataLayout();217 218 unsigned Size = DL.getPointerSizeInBits();219 assert((Size % 8) == 0 && "Need pointer size in bytes.");220 Size /= 8;221 Register Reg = (++MOI)->getReg();222 int64_t Imm = (++MOI)->getImm();223 Locs.emplace_back(StackMaps::Location::Direct, Size,224 getDwarfRegNum(Reg, TRI), Imm);225 break;226 }227 case StackMaps::IndirectMemRefOp: {228 int64_t Size = (++MOI)->getImm();229 assert(Size > 0 && "Need a valid size for indirect memory locations.");230 Register Reg = (++MOI)->getReg();231 int64_t Imm = (++MOI)->getImm();232 Locs.emplace_back(StackMaps::Location::Indirect, Size,233 getDwarfRegNum(Reg, TRI), Imm);234 break;235 }236 case StackMaps::ConstantOp: {237 ++MOI;238 assert(MOI->isImm() && "Expected constant operand.");239 int64_t Imm = MOI->getImm();240 if (isInt<32>(Imm)) {241 Locs.emplace_back(Location::Constant, sizeof(int64_t), 0, Imm);242 } else {243 // ConstPool is intentionally a MapVector of 'uint64_t's (as244 // opposed to 'int64_t's). We should never be in a situation245 // where we have to insert either the tombstone or the empty246 // keys into a map, and for a DenseMap<uint64_t, T> these are247 // (uint64_t)0 and (uint64_t)-1. They can be and are248 // represented using 32 bit integers.249 assert((uint64_t)Imm != DenseMapInfo<uint64_t>::getEmptyKey() &&250 (uint64_t)Imm != DenseMapInfo<uint64_t>::getTombstoneKey() &&251 "empty and tombstone keys should fit in 32 bits!");252 auto Result = ConstPool.insert(std::make_pair(Imm, Imm));253 Locs.emplace_back(Location::ConstantIndex, sizeof(int64_t), 0,254 Result.first - ConstPool.begin());255 }256 break;257 }258 }259 return ++MOI;260 }261 262 // The physical register number will ultimately be encoded as a DWARF regno.263 // The stack map also records the size of a spill slot that can hold the264 // register content. (The runtime can track the actual size of the data type265 // if it needs to.)266 if (MOI->isReg()) {267 // Skip implicit registers (this includes our scratch registers)268 if (MOI->isImplicit())269 return ++MOI;270 271 assert(MOI->getReg().isPhysical() &&272 "Virtreg operands should have been rewritten before now.");273 const TargetRegisterClass *RC = TRI->getMinimalPhysRegClass(MOI->getReg());274 assert(!MOI->getSubReg() && "Physical subreg still around.");275 276 unsigned Offset = 0;277 unsigned DwarfRegNum = getDwarfRegNum(MOI->getReg(), TRI);278 MCRegister LLVMRegNum = *TRI->getLLVMRegNum(DwarfRegNum, false);279 unsigned SubRegIdx = TRI->getSubRegIndex(LLVMRegNum, MOI->getReg());280 if (SubRegIdx)281 Offset = TRI->getSubRegIdxOffset(SubRegIdx);282 283 Locs.emplace_back(Location::Register, TRI->getSpillSize(*RC),284 DwarfRegNum, Offset);285 return ++MOI;286 }287 288 if (MOI->isRegLiveOut())289 LiveOuts = parseRegisterLiveOutMask(MOI->getRegLiveOut());290 291 return ++MOI;292}293 294void StackMaps::print(raw_ostream &OS) {295 const TargetRegisterInfo *TRI =296 AP.MF ? AP.MF->getSubtarget().getRegisterInfo() : nullptr;297 OS << WSMP << "callsites:\n";298 for (const auto &CSI : CSInfos) {299 const LocationVec &CSLocs = CSI.Locations;300 const LiveOutVec &LiveOuts = CSI.LiveOuts;301 302 OS << WSMP << "callsite " << CSI.ID << "\n";303 OS << WSMP << " has " << CSLocs.size() << " locations\n";304 305 unsigned Idx = 0;306 for (const auto &Loc : CSLocs) {307 OS << WSMP << "\t\tLoc " << Idx << ": ";308 switch (Loc.Type) {309 case Location::Unprocessed:310 OS << "<Unprocessed operand>";311 break;312 case Location::Register:313 OS << "Register ";314 if (TRI)315 OS << printReg(Loc.Reg, TRI);316 else317 OS << Loc.Reg;318 break;319 case Location::Direct:320 OS << "Direct ";321 if (TRI)322 OS << printReg(Loc.Reg, TRI);323 else324 OS << Loc.Reg;325 if (Loc.Offset)326 OS << " + " << Loc.Offset;327 break;328 case Location::Indirect:329 OS << "Indirect ";330 if (TRI)331 OS << printReg(Loc.Reg, TRI);332 else333 OS << Loc.Reg;334 OS << "+" << Loc.Offset;335 break;336 case Location::Constant:337 OS << "Constant " << Loc.Offset;338 break;339 case Location::ConstantIndex:340 OS << "Constant Index " << Loc.Offset;341 break;342 }343 OS << "\t[encoding: .byte " << Loc.Type << ", .byte 0"344 << ", .short " << Loc.Size << ", .short " << Loc.Reg << ", .short 0"345 << ", .int " << Loc.Offset << "]\n";346 Idx++;347 }348 349 OS << WSMP << "\thas " << LiveOuts.size() << " live-out registers\n";350 351 Idx = 0;352 for (const auto &LO : LiveOuts) {353 OS << WSMP << "\t\tLO " << Idx << ": ";354 if (TRI)355 OS << printReg(LO.Reg, TRI);356 else357 OS << LO.Reg;358 OS << "\t[encoding: .short " << LO.DwarfRegNum << ", .byte 0, .byte "359 << LO.Size << "]\n";360 Idx++;361 }362 }363}364 365/// Create a live-out register record for the given register Reg.366StackMaps::LiveOutReg367StackMaps::createLiveOutReg(unsigned Reg, const TargetRegisterInfo *TRI) const {368 unsigned DwarfRegNum = getDwarfRegNum(Reg, TRI);369 unsigned Size = TRI->getSpillSize(*TRI->getMinimalPhysRegClass(Reg));370 return LiveOutReg(Reg, DwarfRegNum, Size);371}372 373/// Parse the register live-out mask and return a vector of live-out registers374/// that need to be recorded in the stackmap.375StackMaps::LiveOutVec376StackMaps::parseRegisterLiveOutMask(const uint32_t *Mask) const {377 assert(Mask && "No register mask specified");378 const TargetRegisterInfo *TRI = AP.MF->getSubtarget().getRegisterInfo();379 LiveOutVec LiveOuts;380 381 // Create a LiveOutReg for each bit that is set in the register mask.382 for (unsigned Reg = 0, NumRegs = TRI->getNumRegs(); Reg != NumRegs; ++Reg)383 if ((Mask[Reg / 32] >> (Reg % 32)) & 1)384 LiveOuts.push_back(createLiveOutReg(Reg, TRI));385 386 // We don't need to keep track of a register if its super-register is already387 // in the list. Merge entries that refer to the same dwarf register and use388 // the maximum size that needs to be spilled.389 390 llvm::sort(LiveOuts, [](const LiveOutReg &LHS, const LiveOutReg &RHS) {391 // Only sort by the dwarf register number.392 return LHS.DwarfRegNum < RHS.DwarfRegNum;393 });394 395 for (auto I = LiveOuts.begin(), E = LiveOuts.end(); I != E; ++I) {396 for (auto *II = std::next(I); II != E; ++II) {397 if (I->DwarfRegNum != II->DwarfRegNum) {398 // Skip all the now invalid entries.399 I = --II;400 break;401 }402 I->Size = std::max(I->Size, II->Size);403 if (I->Reg && TRI->isSuperRegister(I->Reg, II->Reg))404 I->Reg = II->Reg;405 II->Reg = 0; // mark for deletion.406 }407 }408 409 llvm::erase_if(LiveOuts, [](const LiveOutReg &LO) { return LO.Reg == 0; });410 411 return LiveOuts;412}413 414// See statepoint MI format description in StatepointOpers' class comment415// in include/llvm/CodeGen/StackMaps.h416void StackMaps::parseStatepointOpers(const MachineInstr &MI,417 MachineInstr::const_mop_iterator MOI,418 MachineInstr::const_mop_iterator MOE,419 LocationVec &Locations,420 LiveOutVec &LiveOuts) {421 LLVM_DEBUG(dbgs() << "record statepoint : " << MI << "\n");422 StatepointOpers SO(&MI);423 MOI = parseOperand(MOI, MOE, Locations, LiveOuts); // CC424 MOI = parseOperand(MOI, MOE, Locations, LiveOuts); // Flags425 MOI = parseOperand(MOI, MOE, Locations, LiveOuts); // Num Deopts426 427 // Record Deopt Args.428 unsigned NumDeoptArgs = Locations.back().Offset;429 assert(Locations.back().Type == Location::Constant);430 assert(NumDeoptArgs == SO.getNumDeoptArgs());431 432 while (NumDeoptArgs--)433 MOI = parseOperand(MOI, MOE, Locations, LiveOuts);434 435 // Record gc base/derived pairs436 assert(MOI->isImm() && MOI->getImm() == StackMaps::ConstantOp);437 ++MOI;438 assert(MOI->isImm());439 unsigned NumGCPointers = MOI->getImm();440 ++MOI;441 if (NumGCPointers) {442 // Map logical index of GC ptr to MI operand index.443 SmallVector<unsigned, 8> GCPtrIndices;444 unsigned GCPtrIdx = (unsigned)SO.getFirstGCPtrIdx();445 assert((int)GCPtrIdx != -1);446 assert(MOI - MI.operands_begin() == GCPtrIdx + 0LL);447 while (NumGCPointers--) {448 GCPtrIndices.push_back(GCPtrIdx);449 GCPtrIdx = StackMaps::getNextMetaArgIdx(&MI, GCPtrIdx);450 }451 452 SmallVector<std::pair<unsigned, unsigned>, 8> GCPairs;453 unsigned NumGCPairs = SO.getGCPointerMap(GCPairs);454 (void)NumGCPairs;455 LLVM_DEBUG(dbgs() << "NumGCPairs = " << NumGCPairs << "\n");456 457 auto MOB = MI.operands_begin();458 for (auto &P : GCPairs) {459 assert(P.first < GCPtrIndices.size() && "base pointer index not found");460 assert(P.second < GCPtrIndices.size() &&461 "derived pointer index not found");462 unsigned BaseIdx = GCPtrIndices[P.first];463 unsigned DerivedIdx = GCPtrIndices[P.second];464 LLVM_DEBUG(dbgs() << "Base : " << BaseIdx << " Derived : " << DerivedIdx465 << "\n");466 (void)parseOperand(MOB + BaseIdx, MOE, Locations, LiveOuts);467 (void)parseOperand(MOB + DerivedIdx, MOE, Locations, LiveOuts);468 }469 470 MOI = MOB + GCPtrIdx;471 }472 473 // Record gc allocas474 assert(MOI < MOE);475 assert(MOI->isImm() && MOI->getImm() == StackMaps::ConstantOp);476 ++MOI;477 unsigned NumAllocas = MOI->getImm();478 ++MOI;479 while (NumAllocas--) {480 MOI = parseOperand(MOI, MOE, Locations, LiveOuts);481 assert(MOI < MOE);482 }483}484 485void StackMaps::recordStackMapOpers(const MCSymbol &MILabel,486 const MachineInstr &MI, uint64_t ID,487 MachineInstr::const_mop_iterator MOI,488 MachineInstr::const_mop_iterator MOE,489 bool recordResult) {490 MCContext &OutContext = AP.OutStreamer->getContext();491 492 LocationVec Locations;493 LiveOutVec LiveOuts;494 495 if (recordResult) {496 assert(PatchPointOpers(&MI).hasDef() && "Stackmap has no return value.");497 parseOperand(MI.operands_begin(), std::next(MI.operands_begin()), Locations,498 LiveOuts);499 }500 501 // Parse operands.502 if (MI.getOpcode() == TargetOpcode::STATEPOINT)503 parseStatepointOpers(MI, MOI, MOE, Locations, LiveOuts);504 else505 while (MOI != MOE)506 MOI = parseOperand(MOI, MOE, Locations, LiveOuts);507 508 // Create an expression to calculate the offset of the callsite from function509 // entry.510 const MCExpr *CSOffsetExpr = MCBinaryExpr::createSub(511 MCSymbolRefExpr::create(&MILabel, OutContext),512 MCSymbolRefExpr::create(AP.CurrentFnSymForSize, OutContext), OutContext);513 514 CSInfos.emplace_back(CSOffsetExpr, ID, std::move(Locations),515 std::move(LiveOuts));516 517 // Record the stack size of the current function and update callsite count.518 const MachineFrameInfo &MFI = AP.MF->getFrameInfo();519 const TargetRegisterInfo *RegInfo = AP.MF->getSubtarget().getRegisterInfo();520 bool HasDynamicFrameSize =521 MFI.hasVarSizedObjects() || RegInfo->hasStackRealignment(*(AP.MF));522 uint64_t FrameSize = HasDynamicFrameSize ? UINT64_MAX : MFI.getStackSize();523 524 auto [CurrentIt, Inserted] = FnInfos.try_emplace(AP.CurrentFnSym, FrameSize);525 if (!Inserted)526 CurrentIt->second.RecordCount++;527}528 529void StackMaps::recordStackMap(const MCSymbol &L, const MachineInstr &MI) {530 assert(MI.getOpcode() == TargetOpcode::STACKMAP && "expected stackmap");531 532 StackMapOpers opers(&MI);533 const int64_t ID = MI.getOperand(PatchPointOpers::IDPos).getImm();534 recordStackMapOpers(L, MI, ID, std::next(MI.operands_begin(),535 opers.getVarIdx()),536 MI.operands_end());537}538 539void StackMaps::recordPatchPoint(const MCSymbol &L, const MachineInstr &MI) {540 assert(MI.getOpcode() == TargetOpcode::PATCHPOINT && "expected patchpoint");541 542 PatchPointOpers opers(&MI);543 const int64_t ID = opers.getID();544 auto MOI = std::next(MI.operands_begin(), opers.getStackMapStartIdx());545 recordStackMapOpers(L, MI, ID, MOI, MI.operands_end(),546 opers.isAnyReg() && opers.hasDef());547 548#ifndef NDEBUG549 // verify anyregcc550 auto &Locations = CSInfos.back().Locations;551 if (opers.isAnyReg()) {552 unsigned NArgs = opers.getNumCallArgs();553 for (unsigned i = 0, e = (opers.hasDef() ? NArgs + 1 : NArgs); i != e; ++i)554 assert(Locations[i].Type == Location::Register &&555 "anyreg arg must be in reg.");556 }557#endif558}559 560void StackMaps::recordStatepoint(const MCSymbol &L, const MachineInstr &MI) {561 assert(MI.getOpcode() == TargetOpcode::STATEPOINT && "expected statepoint");562 563 StatepointOpers opers(&MI);564 const unsigned StartIdx = opers.getVarIdx();565 recordStackMapOpers(L, MI, opers.getID(), MI.operands_begin() + StartIdx,566 MI.operands_end(), false);567}568 569/// Emit the stackmap header.570///571/// Header {572/// uint8 : Stack Map Version (currently 3)573/// uint8 : Reserved (expected to be 0)574/// uint16 : Reserved (expected to be 0)575/// }576/// uint32 : NumFunctions577/// uint32 : NumConstants578/// uint32 : NumRecords579void StackMaps::emitStackmapHeader(MCStreamer &OS) {580 // Header.581 OS.emitIntValue(StackMapVersion, 1); // Version.582 OS.emitIntValue(0, 1); // Reserved.583 OS.emitInt16(0); // Reserved.584 585 // Num functions.586 LLVM_DEBUG(dbgs() << WSMP << "#functions = " << FnInfos.size() << '\n');587 OS.emitInt32(FnInfos.size());588 // Num constants.589 LLVM_DEBUG(dbgs() << WSMP << "#constants = " << ConstPool.size() << '\n');590 OS.emitInt32(ConstPool.size());591 // Num callsites.592 LLVM_DEBUG(dbgs() << WSMP << "#callsites = " << CSInfos.size() << '\n');593 OS.emitInt32(CSInfos.size());594}595 596/// Emit the function frame record for each function.597///598/// StkSizeRecord[NumFunctions] {599/// uint64 : Function Address600/// uint64 : Stack Size601/// uint64 : Record Count602/// }603void StackMaps::emitFunctionFrameRecords(MCStreamer &OS) {604 // Function Frame records.605 LLVM_DEBUG(dbgs() << WSMP << "functions:\n");606 for (auto const &FR : FnInfos) {607 LLVM_DEBUG(dbgs() << WSMP << "function addr: " << FR.first608 << " frame size: " << FR.second.StackSize609 << " callsite count: " << FR.second.RecordCount << '\n');610 OS.emitSymbolValue(FR.first, 8);611 OS.emitIntValue(FR.second.StackSize, 8);612 OS.emitIntValue(FR.second.RecordCount, 8);613 }614}615 616/// Emit the constant pool.617///618/// int64 : Constants[NumConstants]619void StackMaps::emitConstantPoolEntries(MCStreamer &OS) {620 // Constant pool entries.621 LLVM_DEBUG(dbgs() << WSMP << "constants:\n");622 for (const auto &ConstEntry : ConstPool) {623 LLVM_DEBUG(dbgs() << WSMP << ConstEntry.second << '\n');624 OS.emitIntValue(ConstEntry.second, 8);625 }626}627 628/// Emit the callsite info for each callsite.629///630/// StkMapRecord[NumRecords] {631/// uint64 : PatchPoint ID632/// uint32 : Instruction Offset633/// uint16 : Reserved (record flags)634/// uint16 : NumLocations635/// Location[NumLocations] {636/// uint8 : Register | Direct | Indirect | Constant | ConstantIndex637/// uint8 : Size in Bytes638/// uint16 : Dwarf RegNum639/// int32 : Offset640/// }641/// uint16 : Padding642/// uint16 : NumLiveOuts643/// LiveOuts[NumLiveOuts] {644/// uint16 : Dwarf RegNum645/// uint8 : Reserved646/// uint8 : Size in Bytes647/// }648/// uint32 : Padding (only if required to align to 8 byte)649/// }650///651/// Location Encoding, Type, Value:652/// 0x1, Register, Reg (value in register)653/// 0x2, Direct, Reg + Offset (frame index)654/// 0x3, Indirect, [Reg + Offset] (spilled value)655/// 0x4, Constant, Offset (small constant)656/// 0x5, ConstIndex, Constants[Offset] (large constant)657void StackMaps::emitCallsiteEntries(MCStreamer &OS) {658 LLVM_DEBUG(print(dbgs()));659 // Callsite entries.660 for (const auto &CSI : CSInfos) {661 const LocationVec &CSLocs = CSI.Locations;662 const LiveOutVec &LiveOuts = CSI.LiveOuts;663 664 // Verify stack map entry. It's better to communicate a problem to the665 // runtime than crash in case of in-process compilation. Currently, we do666 // simple overflow checks, but we may eventually communicate other667 // compilation errors this way.668 if (CSLocs.size() > UINT16_MAX || LiveOuts.size() > UINT16_MAX) {669 OS.emitIntValue(UINT64_MAX, 8); // Invalid ID.670 OS.emitValue(CSI.CSOffsetExpr, 4);671 OS.emitInt16(0); // Reserved.672 OS.emitInt16(0); // 0 locations.673 OS.emitInt16(0); // padding.674 OS.emitInt16(0); // 0 live-out registers.675 OS.emitInt32(0); // padding.676 continue;677 }678 679 OS.emitIntValue(CSI.ID, 8);680 OS.emitValue(CSI.CSOffsetExpr, 4);681 682 // Reserved for flags.683 OS.emitInt16(0);684 OS.emitInt16(CSLocs.size());685 686 for (const auto &Loc : CSLocs) {687 OS.emitIntValue(Loc.Type, 1);688 OS.emitIntValue(0, 1); // Reserved689 OS.emitInt16(Loc.Size);690 OS.emitInt16(Loc.Reg);691 OS.emitInt16(0); // Reserved692 OS.emitInt32(Loc.Offset);693 }694 695 // Emit alignment to 8 byte.696 OS.emitValueToAlignment(Align(8));697 698 // Num live-out registers and padding to align to 4 byte.699 OS.emitInt16(0);700 OS.emitInt16(LiveOuts.size());701 702 for (const auto &LO : LiveOuts) {703 OS.emitInt16(LO.DwarfRegNum);704 OS.emitIntValue(0, 1);705 OS.emitIntValue(LO.Size, 1);706 }707 // Emit alignment to 8 byte.708 OS.emitValueToAlignment(Align(8));709 }710}711 712/// Serialize the stackmap data.713void StackMaps::serializeToStackMapSection() {714 (void)WSMP;715 // Bail out if there's no stack map data.716 assert((!CSInfos.empty() || ConstPool.empty()) &&717 "Expected empty constant pool too!");718 assert((!CSInfos.empty() || FnInfos.empty()) &&719 "Expected empty function record too!");720 if (CSInfos.empty())721 return;722 723 MCContext &OutContext = AP.OutStreamer->getContext();724 MCStreamer &OS = *AP.OutStreamer;725 726 // Create the section.727 MCSection *StackMapSection =728 OutContext.getObjectFileInfo()->getStackMapSection();729 OS.switchSection(StackMapSection);730 731 // Emit a dummy symbol to force section inclusion.732 OS.emitLabel(OutContext.getOrCreateSymbol(Twine("__LLVM_StackMaps")));733 734 // Serialize data.735 LLVM_DEBUG(dbgs() << "********** Stack Map Output **********\n");736 emitStackmapHeader(OS);737 emitFunctionFrameRecords(OS);738 emitConstantPoolEntries(OS);739 emitCallsiteEntries(OS);740 OS.addBlankLine();741 742 // Clean up.743 CSInfos.clear();744 ConstPool.clear();745}746