llvm/llvm/lib/CodeGen/StackMaps.cpp

//===- StackMaps.cpp ------------------------------------------------------===//
//
// 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
//
//===----------------------------------------------------------------------===//

#include "llvm/CodeGen/StackMaps.h"
#include "llvm/ADT/DenseMapInfo.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/Twine.h"
#include "llvm/CodeGen/AsmPrinter.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineInstr.h"
#include "llvm/CodeGen/MachineOperand.h"
#include "llvm/CodeGen/TargetOpcodes.h"
#include "llvm/CodeGen/TargetRegisterInfo.h"
#include "llvm/CodeGen/TargetSubtargetInfo.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCObjectFileInfo.h"
#include "llvm/MC/MCRegisterInfo.h"
#include "llvm/MC/MCStreamer.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/Support/raw_ostream.h"
#include <algorithm>
#include <cassert>
#include <cstdint>
#include <iterator>
#include <utility>

usingnamespacellvm;

#define DEBUG_TYPE …

static cl::opt<int> StackMapVersion(
    "stackmap-version", cl::init(3), cl::Hidden,
    cl::desc("Specify the stackmap encoding version (default = 3)"));

const char *StackMaps::WSMP = …;

static uint64_t getConstMetaVal(const MachineInstr &MI, unsigned Idx) { … }

StackMapOpers::StackMapOpers(const MachineInstr *MI)
  : … { … }

PatchPointOpers::PatchPointOpers(const MachineInstr *MI)
    : … { … }

unsigned PatchPointOpers::getNextScratchIdx(unsigned StartIdx) const { … }

unsigned StatepointOpers::getNumGcMapEntriesIdx() { … }

unsigned StatepointOpers::getNumAllocaIdx() { … }

unsigned StatepointOpers::getNumGCPtrIdx() { … }

int StatepointOpers::getFirstGCPtrIdx() { … }

unsigned StatepointOpers::getGCPointerMap(
    SmallVectorImpl<std::pair<unsigned, unsigned>> &GCMap) { … }

bool StatepointOpers::isFoldableReg(Register Reg) const { … }

bool StatepointOpers::isFoldableReg(const MachineInstr *MI, Register Reg) { … }

StackMaps::StackMaps(AsmPrinter &AP) : … { … }

unsigned StackMaps::getNextMetaArgIdx(const MachineInstr *MI, unsigned CurIdx) { … }

/// Go up the super-register chain until we hit a valid dwarf register number.
static unsigned getDwarfRegNum(unsigned Reg, const TargetRegisterInfo *TRI) { … }

MachineInstr::const_mop_iterator
StackMaps::parseOperand(MachineInstr::const_mop_iterator MOI,
                        MachineInstr::const_mop_iterator MOE, LocationVec &Locs,
                        LiveOutVec &LiveOuts) { … }

void StackMaps::print(raw_ostream &OS) { … }

/// Create a live-out register record for the given register Reg.
StackMaps::LiveOutReg
StackMaps::createLiveOutReg(unsigned Reg, const TargetRegisterInfo *TRI) const { … }

/// Parse the register live-out mask and return a vector of live-out registers
/// that need to be recorded in the stackmap.
StackMaps::LiveOutVec
StackMaps::parseRegisterLiveOutMask(const uint32_t *Mask) const { … }

// See statepoint MI format description in StatepointOpers' class comment
// in include/llvm/CodeGen/StackMaps.h
void StackMaps::parseStatepointOpers(const MachineInstr &MI,
                                     MachineInstr::const_mop_iterator MOI,
                                     MachineInstr::const_mop_iterator MOE,
                                     LocationVec &Locations,
                                     LiveOutVec &LiveOuts) { … }

void StackMaps::recordStackMapOpers(const MCSymbol &MILabel,
                                    const MachineInstr &MI, uint64_t ID,
                                    MachineInstr::const_mop_iterator MOI,
                                    MachineInstr::const_mop_iterator MOE,
                                    bool recordResult) { … }

void StackMaps::recordStackMap(const MCSymbol &L, const MachineInstr &MI) { … }

void StackMaps::recordPatchPoint(const MCSymbol &L, const MachineInstr &MI) { … }

void StackMaps::recordStatepoint(const MCSymbol &L, const MachineInstr &MI) { … }

/// Emit the stackmap header.
///
/// Header {
///   uint8  : Stack Map Version (currently 3)
///   uint8  : Reserved (expected to be 0)
///   uint16 : Reserved (expected to be 0)
/// }
/// uint32 : NumFunctions
/// uint32 : NumConstants
/// uint32 : NumRecords
void StackMaps::emitStackmapHeader(MCStreamer &OS) { … }

/// Emit the function frame record for each function.
///
/// StkSizeRecord[NumFunctions] {
///   uint64 : Function Address
///   uint64 : Stack Size
///   uint64 : Record Count
/// }
void StackMaps::emitFunctionFrameRecords(MCStreamer &OS) { … }

/// Emit the constant pool.
///
/// int64  : Constants[NumConstants]
void StackMaps::emitConstantPoolEntries(MCStreamer &OS) { … }

/// Emit the callsite info for each callsite.
///
/// StkMapRecord[NumRecords] {
///   uint64 : PatchPoint ID
///   uint32 : Instruction Offset
///   uint16 : Reserved (record flags)
///   uint16 : NumLocations
///   Location[NumLocations] {
///     uint8  : Register | Direct | Indirect | Constant | ConstantIndex
///     uint8  : Size in Bytes
///     uint16 : Dwarf RegNum
///     int32  : Offset
///   }
///   uint16 : Padding
///   uint16 : NumLiveOuts
///   LiveOuts[NumLiveOuts] {
///     uint16 : Dwarf RegNum
///     uint8  : Reserved
///     uint8  : Size in Bytes
///   }
///   uint32 : Padding (only if required to align to 8 byte)
/// }
///
/// Location Encoding, Type, Value:
///   0x1, Register, Reg                 (value in register)
///   0x2, Direct, Reg + Offset          (frame index)
///   0x3, Indirect, [Reg + Offset]      (spilled value)
///   0x4, Constant, Offset              (small constant)
///   0x5, ConstIndex, Constants[Offset] (large constant)
void StackMaps::emitCallsiteEntries(MCStreamer &OS) { … }

/// Serialize the stackmap data.
void StackMaps::serializeToStackMapSection() { … }