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llvm-project/llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp

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//===- AArch64AsmPrinter.cpp - AArch64 LLVM assembly writer ---------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
//
// This file contains a printer that converts from our internal representation
// of machine-dependent LLVM code to the AArch64 assembly language.
//
//===----------------------------------------------------------------------===//
#include "AArch64.h"
#include "AArch64MCInstLower.h"
#include "AArch64MachineFunctionInfo.h"
#include "AArch64RegisterInfo.h"
#include "AArch64Subtarget.h"
#include "AArch64TargetObjectFile.h"
#include "MCTargetDesc/AArch64AddressingModes.h"
#include "MCTargetDesc/AArch64InstPrinter.h"
#include "MCTargetDesc/AArch64MCExpr.h"
#include "MCTargetDesc/AArch64MCTargetDesc.h"
#include "MCTargetDesc/AArch64TargetStreamer.h"
#include "TargetInfo/AArch64TargetInfo.h"
#include "Utils/AArch64BaseInfo.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/Triple.h"
#include "llvm/ADT/Twine.h"
#include "llvm/BinaryFormat/COFF.h"
#include "llvm/BinaryFormat/ELF.h"
#include "llvm/CodeGen/AsmPrinter.h"
#include "llvm/CodeGen/MachineBasicBlock.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineInstr.h"
#include "llvm/CodeGen/MachineJumpTableInfo.h"
#include "llvm/CodeGen/MachineModuleInfoImpls.h"
#include "llvm/CodeGen/MachineOperand.h"
#include "llvm/CodeGen/StackMaps.h"
#include "llvm/CodeGen/TargetRegisterInfo.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/DebugInfoMetadata.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCInst.h"
#include "llvm/MC/MCInstBuilder.h"
#include "llvm/MC/MCSectionELF.h"
#include "llvm/MC/MCStreamer.h"
#include "llvm/MC/MCSymbol.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/TargetRegistry.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Target/TargetMachine.h"
#include <algorithm>
#include <cassert>
#include <cstdint>
#include <map>
#include <memory>
using namespace llvm;
#define DEBUG_TYPE "asm-printer"
namespace {
class AArch64AsmPrinter : public AsmPrinter {
AArch64MCInstLower MCInstLowering;
StackMaps SM;
const AArch64Subtarget *STI;
public:
AArch64AsmPrinter(TargetMachine &TM, std::unique_ptr<MCStreamer> Streamer)
: AsmPrinter(TM, std::move(Streamer)), MCInstLowering(OutContext, *this),
SM(*this) {}
StringRef getPassName() const override { return "AArch64 Assembly Printer"; }
/// Wrapper for MCInstLowering.lowerOperand() for the
/// tblgen'erated pseudo lowering.
bool lowerOperand(const MachineOperand &MO, MCOperand &MCOp) const {
return MCInstLowering.lowerOperand(MO, MCOp);
}
void EmitJumpTableInfo() override;
void emitJumpTableEntry(const MachineJumpTableInfo *MJTI,
const MachineBasicBlock *MBB, unsigned JTI);
void LowerJumpTableDestSmall(MCStreamer &OutStreamer, const MachineInstr &MI);
void LowerSTACKMAP(MCStreamer &OutStreamer, StackMaps &SM,
const MachineInstr &MI);
void LowerPATCHPOINT(MCStreamer &OutStreamer, StackMaps &SM,
const MachineInstr &MI);
void LowerPATCHABLE_FUNCTION_ENTER(const MachineInstr &MI);
void LowerPATCHABLE_FUNCTION_EXIT(const MachineInstr &MI);
void LowerPATCHABLE_TAIL_CALL(const MachineInstr &MI);
std::map<std::pair<unsigned, uint32_t>, MCSymbol *> HwasanMemaccessSymbols;
void LowerHWASAN_CHECK_MEMACCESS(const MachineInstr &MI);
void EmitHwasanMemaccessSymbols(Module &M);
void EmitSled(const MachineInstr &MI, SledKind Kind);
/// tblgen'erated driver function for lowering simple MI->MC
/// pseudo instructions.
bool emitPseudoExpansionLowering(MCStreamer &OutStreamer,
const MachineInstr *MI);
void EmitInstruction(const MachineInstr *MI) override;
void getAnalysisUsage(AnalysisUsage &AU) const override {
AsmPrinter::getAnalysisUsage(AU);
AU.setPreservesAll();
}
bool runOnMachineFunction(MachineFunction &MF) override {
AArch64FI = MF.getInfo<AArch64FunctionInfo>();
STI = static_cast<const AArch64Subtarget*>(&MF.getSubtarget());
SetupMachineFunction(MF);
if (STI->isTargetCOFF()) {
bool Internal = MF.getFunction().hasInternalLinkage();
COFF::SymbolStorageClass Scl = Internal ? COFF::IMAGE_SYM_CLASS_STATIC
: COFF::IMAGE_SYM_CLASS_EXTERNAL;
int Type =
COFF::IMAGE_SYM_DTYPE_FUNCTION << COFF::SCT_COMPLEX_TYPE_SHIFT;
OutStreamer->BeginCOFFSymbolDef(CurrentFnSym);
OutStreamer->EmitCOFFSymbolStorageClass(Scl);
OutStreamer->EmitCOFFSymbolType(Type);
OutStreamer->EndCOFFSymbolDef();
}
// Emit the rest of the function body.
EmitFunctionBody();
// Emit the XRay table for this function.
emitXRayTable();
// We didn't modify anything.
return false;
}
private:
void printOperand(const MachineInstr *MI, unsigned OpNum, raw_ostream &O);
bool printAsmMRegister(const MachineOperand &MO, char Mode, raw_ostream &O);
bool printAsmRegInClass(const MachineOperand &MO,
const TargetRegisterClass *RC, bool isVector,
raw_ostream &O);
bool PrintAsmOperand(const MachineInstr *MI, unsigned OpNum,
const char *ExtraCode, raw_ostream &O) override;
bool PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNum,
const char *ExtraCode, raw_ostream &O) override;
void PrintDebugValueComment(const MachineInstr *MI, raw_ostream &OS);
void EmitFunctionBodyEnd() override;
MCSymbol *GetCPISymbol(unsigned CPID) const override;
void EmitEndOfAsmFile(Module &M) override;
AArch64FunctionInfo *AArch64FI = nullptr;
/// Emit the LOHs contained in AArch64FI.
void EmitLOHs();
/// Emit instruction to set float register to zero.
void EmitFMov0(const MachineInstr &MI);
using MInstToMCSymbol = std::map<const MachineInstr *, MCSymbol *>;
MInstToMCSymbol LOHInstToLabel;
};
} // end anonymous namespace
void AArch64AsmPrinter::LowerPATCHABLE_FUNCTION_ENTER(const MachineInstr &MI)
{
EmitSled(MI, SledKind::FUNCTION_ENTER);
}
void AArch64AsmPrinter::LowerPATCHABLE_FUNCTION_EXIT(const MachineInstr &MI)
{
EmitSled(MI, SledKind::FUNCTION_EXIT);
}
void AArch64AsmPrinter::LowerPATCHABLE_TAIL_CALL(const MachineInstr &MI)
{
EmitSled(MI, SledKind::TAIL_CALL);
}
void AArch64AsmPrinter::EmitSled(const MachineInstr &MI, SledKind Kind)
{
static const int8_t NoopsInSledCount = 7;
// We want to emit the following pattern:
//
// .Lxray_sled_N:
// ALIGN
// B #32
// ; 7 NOP instructions (28 bytes)
// .tmpN
//
// We need the 28 bytes (7 instructions) because at runtime, we'd be patching
// over the full 32 bytes (8 instructions) with the following pattern:
//
// STP X0, X30, [SP, #-16]! ; push X0 and the link register to the stack
// LDR W0, #12 ; W0 := function ID
// LDR X16,#12 ; X16 := addr of __xray_FunctionEntry or __xray_FunctionExit
// BLR X16 ; call the tracing trampoline
// ;DATA: 32 bits of function ID
// ;DATA: lower 32 bits of the address of the trampoline
// ;DATA: higher 32 bits of the address of the trampoline
// LDP X0, X30, [SP], #16 ; pop X0 and the link register from the stack
//
OutStreamer->EmitCodeAlignment(4);
auto CurSled = OutContext.createTempSymbol("xray_sled_", true);
OutStreamer->EmitLabel(CurSled);
auto Target = OutContext.createTempSymbol();
// Emit "B #32" instruction, which jumps over the next 28 bytes.
// The operand has to be the number of 4-byte instructions to jump over,
// including the current instruction.
EmitToStreamer(*OutStreamer, MCInstBuilder(AArch64::B).addImm(8));
for (int8_t I = 0; I < NoopsInSledCount; I++)
EmitToStreamer(*OutStreamer, MCInstBuilder(AArch64::HINT).addImm(0));
OutStreamer->EmitLabel(Target);
recordSled(CurSled, MI, Kind);
}
void AArch64AsmPrinter::LowerHWASAN_CHECK_MEMACCESS(const MachineInstr &MI) {
unsigned Reg = MI.getOperand(0).getReg();
uint32_t AccessInfo = MI.getOperand(1).getImm();
MCSymbol *&Sym = HwasanMemaccessSymbols[{Reg, AccessInfo}];
if (!Sym) {
// FIXME: Make this work on non-ELF.
if (!TM.getTargetTriple().isOSBinFormatELF())
report_fatal_error("llvm.hwasan.check.memaccess only supported on ELF");
std::string SymName = "__hwasan_check_x" + utostr(Reg - AArch64::X0) + "_" +
utostr(AccessInfo);
Sym = OutContext.getOrCreateSymbol(SymName);
}
EmitToStreamer(*OutStreamer,
MCInstBuilder(AArch64::BL)
.addExpr(MCSymbolRefExpr::create(Sym, OutContext)));
}
void AArch64AsmPrinter::EmitHwasanMemaccessSymbols(Module &M) {
if (HwasanMemaccessSymbols.empty())
return;
const Triple &TT = TM.getTargetTriple();
assert(TT.isOSBinFormatELF());
std::unique_ptr<MCSubtargetInfo> STI(
TM.getTarget().createMCSubtargetInfo(TT.str(), "", ""));
MCSymbol *HwasanTagMismatchSym =
OutContext.getOrCreateSymbol("__hwasan_tag_mismatch");
const MCSymbolRefExpr *HwasanTagMismatchRef =
MCSymbolRefExpr::create(HwasanTagMismatchSym, OutContext);
for (auto &P : HwasanMemaccessSymbols) {
unsigned Reg = P.first.first;
uint32_t AccessInfo = P.first.second;
MCSymbol *Sym = P.second;
OutStreamer->SwitchSection(OutContext.getELFSection(
".text.hot", ELF::SHT_PROGBITS,
ELF::SHF_EXECINSTR | ELF::SHF_ALLOC | ELF::SHF_GROUP, 0,
Sym->getName()));
OutStreamer->EmitSymbolAttribute(Sym, MCSA_ELF_TypeFunction);
OutStreamer->EmitSymbolAttribute(Sym, MCSA_Weak);
OutStreamer->EmitSymbolAttribute(Sym, MCSA_Hidden);
OutStreamer->EmitLabel(Sym);
OutStreamer->EmitInstruction(MCInstBuilder(AArch64::UBFMXri)
.addReg(AArch64::X16)
.addReg(Reg)
.addImm(4)
.addImm(55),
*STI);
OutStreamer->EmitInstruction(MCInstBuilder(AArch64::LDRBBroX)
.addReg(AArch64::W16)
.addReg(AArch64::X9)
.addReg(AArch64::X16)
.addImm(0)
.addImm(0),
*STI);
OutStreamer->EmitInstruction(
MCInstBuilder(AArch64::SUBSXrs)
.addReg(AArch64::XZR)
.addReg(AArch64::X16)
.addReg(Reg)
.addImm(AArch64_AM::getShifterImm(AArch64_AM::LSR, 56)),
*STI);
MCSymbol *HandlePartialSym = OutContext.createTempSymbol();
OutStreamer->EmitInstruction(
MCInstBuilder(AArch64::Bcc)
.addImm(AArch64CC::NE)
.addExpr(MCSymbolRefExpr::create(HandlePartialSym, OutContext)),
*STI);
MCSymbol *ReturnSym = OutContext.createTempSymbol();
OutStreamer->EmitLabel(ReturnSym);
OutStreamer->EmitInstruction(
MCInstBuilder(AArch64::RET).addReg(AArch64::LR), *STI);
OutStreamer->EmitLabel(HandlePartialSym);
OutStreamer->EmitInstruction(MCInstBuilder(AArch64::SUBSWri)
.addReg(AArch64::WZR)
.addReg(AArch64::W16)
.addImm(15)
.addImm(0),
*STI);
MCSymbol *HandleMismatchSym = OutContext.createTempSymbol();
OutStreamer->EmitInstruction(
MCInstBuilder(AArch64::Bcc)
.addImm(AArch64CC::HI)
.addExpr(MCSymbolRefExpr::create(HandleMismatchSym, OutContext)),
*STI);
OutStreamer->EmitInstruction(
MCInstBuilder(AArch64::ANDXri)
.addReg(AArch64::X17)
.addReg(Reg)
.addImm(AArch64_AM::encodeLogicalImmediate(0xf, 64)),
*STI);
unsigned Size = 1 << (AccessInfo & 0xf);
if (Size != 1)
OutStreamer->EmitInstruction(MCInstBuilder(AArch64::ADDXri)
.addReg(AArch64::X17)
.addReg(AArch64::X17)
.addImm(Size - 1)
.addImm(0),
*STI);
OutStreamer->EmitInstruction(MCInstBuilder(AArch64::SUBSWrs)
.addReg(AArch64::WZR)
.addReg(AArch64::W16)
.addReg(AArch64::W17)
.addImm(0),
*STI);
OutStreamer->EmitInstruction(
MCInstBuilder(AArch64::Bcc)
.addImm(AArch64CC::LS)
.addExpr(MCSymbolRefExpr::create(HandleMismatchSym, OutContext)),
*STI);
OutStreamer->EmitInstruction(
MCInstBuilder(AArch64::ORRXri)
.addReg(AArch64::X16)
.addReg(Reg)
.addImm(AArch64_AM::encodeLogicalImmediate(0xf, 64)),
*STI);
OutStreamer->EmitInstruction(MCInstBuilder(AArch64::LDRBBui)
.addReg(AArch64::W16)
.addReg(AArch64::X16)
.addImm(0),
*STI);
OutStreamer->EmitInstruction(
MCInstBuilder(AArch64::SUBSXrs)
.addReg(AArch64::XZR)
.addReg(AArch64::X16)
.addReg(Reg)
.addImm(AArch64_AM::getShifterImm(AArch64_AM::LSR, 56)),
*STI);
OutStreamer->EmitInstruction(
MCInstBuilder(AArch64::Bcc)
.addImm(AArch64CC::EQ)
.addExpr(MCSymbolRefExpr::create(ReturnSym, OutContext)),
*STI);
OutStreamer->EmitLabel(HandleMismatchSym);
OutStreamer->EmitInstruction(MCInstBuilder(AArch64::STPXpre)
.addReg(AArch64::SP)
.addReg(AArch64::X0)
.addReg(AArch64::X1)
.addReg(AArch64::SP)
.addImm(-32),
*STI);
OutStreamer->EmitInstruction(MCInstBuilder(AArch64::STPXi)
.addReg(AArch64::FP)
.addReg(AArch64::LR)
.addReg(AArch64::SP)
.addImm(29),
*STI);
if (Reg != AArch64::X0)
OutStreamer->EmitInstruction(MCInstBuilder(AArch64::ORRXrs)
.addReg(AArch64::X0)
.addReg(AArch64::XZR)
.addReg(Reg)
.addImm(0),
*STI);
OutStreamer->EmitInstruction(MCInstBuilder(AArch64::MOVZXi)
.addReg(AArch64::X1)
.addImm(AccessInfo)
.addImm(0),
*STI);
// Intentionally load the GOT entry and branch to it, rather than possibly
// late binding the function, which may clobber the registers before we have
// a chance to save them.
OutStreamer->EmitInstruction(
MCInstBuilder(AArch64::ADRP)
.addReg(AArch64::X16)
.addExpr(AArch64MCExpr::create(
HwasanTagMismatchRef,
AArch64MCExpr::VariantKind::VK_GOT_PAGE, OutContext)),
*STI);
OutStreamer->EmitInstruction(
MCInstBuilder(AArch64::LDRXui)
.addReg(AArch64::X16)
.addReg(AArch64::X16)
.addExpr(AArch64MCExpr::create(
HwasanTagMismatchRef,
AArch64MCExpr::VariantKind::VK_GOT_LO12, OutContext)),
*STI);
OutStreamer->EmitInstruction(
MCInstBuilder(AArch64::BR).addReg(AArch64::X16), *STI);
}
}
void AArch64AsmPrinter::EmitEndOfAsmFile(Module &M) {
EmitHwasanMemaccessSymbols(M);
const Triple &TT = TM.getTargetTriple();
if (TT.isOSBinFormatMachO()) {
// Funny Darwin hack: This flag tells the linker that no global symbols
// contain code that falls through to other global symbols (e.g. the obvious
// implementation of multiple entry points). If this doesn't occur, the
// linker can safely perform dead code stripping. Since LLVM never
// generates code that does this, it is always safe to set.
OutStreamer->EmitAssemblerFlag(MCAF_SubsectionsViaSymbols);
emitStackMaps(SM);
}
}
void AArch64AsmPrinter::EmitLOHs() {
SmallVector<MCSymbol *, 3> MCArgs;
for (const auto &D : AArch64FI->getLOHContainer()) {
for (const MachineInstr *MI : D.getArgs()) {
MInstToMCSymbol::iterator LabelIt = LOHInstToLabel.find(MI);
assert(LabelIt != LOHInstToLabel.end() &&
"Label hasn't been inserted for LOH related instruction");
MCArgs.push_back(LabelIt->second);
}
OutStreamer->EmitLOHDirective(D.getKind(), MCArgs);
MCArgs.clear();
}
}
void AArch64AsmPrinter::EmitFunctionBodyEnd() {
if (!AArch64FI->getLOHRelated().empty())
EmitLOHs();
}
/// GetCPISymbol - Return the symbol for the specified constant pool entry.
MCSymbol *AArch64AsmPrinter::GetCPISymbol(unsigned CPID) const {
// Darwin uses a linker-private symbol name for constant-pools (to
// avoid addends on the relocation?), ELF has no such concept and
// uses a normal private symbol.
if (!getDataLayout().getLinkerPrivateGlobalPrefix().empty())
return OutContext.getOrCreateSymbol(
Twine(getDataLayout().getLinkerPrivateGlobalPrefix()) + "CPI" +
Twine(getFunctionNumber()) + "_" + Twine(CPID));
return AsmPrinter::GetCPISymbol(CPID);
}
void AArch64AsmPrinter::printOperand(const MachineInstr *MI, unsigned OpNum,
raw_ostream &O) {
const MachineOperand &MO = MI->getOperand(OpNum);
switch (MO.getType()) {
default:
llvm_unreachable("<unknown operand type>");
case MachineOperand::MO_Register: {
unsigned Reg = MO.getReg();
assert(Register::isPhysicalRegister(Reg));
assert(!MO.getSubReg() && "Subregs should be eliminated!");
O << AArch64InstPrinter::getRegisterName(Reg);
break;
}
case MachineOperand::MO_Immediate: {
int64_t Imm = MO.getImm();
O << '#' << Imm;
break;
}
case MachineOperand::MO_GlobalAddress: {
PrintSymbolOperand(MO, O);
break;
}
case MachineOperand::MO_BlockAddress: {
MCSymbol *Sym = GetBlockAddressSymbol(MO.getBlockAddress());
Sym->print(O, MAI);
break;
}
}
}
bool AArch64AsmPrinter::printAsmMRegister(const MachineOperand &MO, char Mode,
raw_ostream &O) {
unsigned Reg = MO.getReg();
switch (Mode) {
default:
return true; // Unknown mode.
case 'w':
Reg = getWRegFromXReg(Reg);
break;
case 'x':
Reg = getXRegFromWReg(Reg);
break;
}
O << AArch64InstPrinter::getRegisterName(Reg);
return false;
}
// Prints the register in MO using class RC using the offset in the
// new register class. This should not be used for cross class
// printing.
bool AArch64AsmPrinter::printAsmRegInClass(const MachineOperand &MO,
const TargetRegisterClass *RC,
bool isVector, raw_ostream &O) {
assert(MO.isReg() && "Should only get here with a register!");
const TargetRegisterInfo *RI = STI->getRegisterInfo();
unsigned Reg = MO.getReg();
unsigned RegToPrint = RC->getRegister(RI->getEncodingValue(Reg));
assert(RI->regsOverlap(RegToPrint, Reg));
O << AArch64InstPrinter::getRegisterName(
RegToPrint, isVector ? AArch64::vreg : AArch64::NoRegAltName);
return false;
}
bool AArch64AsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNum,
const char *ExtraCode, raw_ostream &O) {
const MachineOperand &MO = MI->getOperand(OpNum);
// First try the generic code, which knows about modifiers like 'c' and 'n'.
if (!AsmPrinter::PrintAsmOperand(MI, OpNum, ExtraCode, O))
return false;
// Does this asm operand have a single letter operand modifier?
if (ExtraCode && ExtraCode[0]) {
if (ExtraCode[1] != 0)
return true; // Unknown modifier.
switch (ExtraCode[0]) {
default:
return true; // Unknown modifier.
case 'w': // Print W register
case 'x': // Print X register
if (MO.isReg())
return printAsmMRegister(MO, ExtraCode[0], O);
if (MO.isImm() && MO.getImm() == 0) {
unsigned Reg = ExtraCode[0] == 'w' ? AArch64::WZR : AArch64::XZR;
O << AArch64InstPrinter::getRegisterName(Reg);
return false;
}
printOperand(MI, OpNum, O);
return false;
case 'b': // Print B register.
case 'h': // Print H register.
case 's': // Print S register.
case 'd': // Print D register.
case 'q': // Print Q register.
if (MO.isReg()) {
const TargetRegisterClass *RC;
switch (ExtraCode[0]) {
case 'b':
RC = &AArch64::FPR8RegClass;
break;
case 'h':
RC = &AArch64::FPR16RegClass;
break;
case 's':
RC = &AArch64::FPR32RegClass;
break;
case 'd':
RC = &AArch64::FPR64RegClass;
break;
case 'q':
RC = &AArch64::FPR128RegClass;
break;
default:
return true;
}
return printAsmRegInClass(MO, RC, false /* vector */, O);
}
printOperand(MI, OpNum, O);
return false;
}
}
// According to ARM, we should emit x and v registers unless we have a
// modifier.
if (MO.isReg()) {
unsigned Reg = MO.getReg();
// If this is a w or x register, print an x register.
if (AArch64::GPR32allRegClass.contains(Reg) ||
AArch64::GPR64allRegClass.contains(Reg))
return printAsmMRegister(MO, 'x', O);
// If this is a b, h, s, d, or q register, print it as a v register.
return printAsmRegInClass(MO, &AArch64::FPR128RegClass, true /* vector */,
O);
}
printOperand(MI, OpNum, O);
return false;
}
bool AArch64AsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI,
unsigned OpNum,
const char *ExtraCode,
raw_ostream &O) {
if (ExtraCode && ExtraCode[0] && ExtraCode[0] != 'a')
return true; // Unknown modifier.
const MachineOperand &MO = MI->getOperand(OpNum);
assert(MO.isReg() && "unexpected inline asm memory operand");
O << "[" << AArch64InstPrinter::getRegisterName(MO.getReg()) << "]";
return false;
}
void AArch64AsmPrinter::PrintDebugValueComment(const MachineInstr *MI,
raw_ostream &OS) {
unsigned NOps = MI->getNumOperands();
assert(NOps == 4);
OS << '\t' << MAI->getCommentString() << "DEBUG_VALUE: ";
// cast away const; DIetc do not take const operands for some reason.
OS << cast<DILocalVariable>(MI->getOperand(NOps - 2).getMetadata())
->getName();
OS << " <- ";
// Frame address. Currently handles register +- offset only.
assert(MI->getOperand(0).isReg() && MI->getOperand(1).isImm());
OS << '[';
printOperand(MI, 0, OS);
OS << '+';
printOperand(MI, 1, OS);
OS << ']';
OS << "+";
printOperand(MI, NOps - 2, OS);
}
void AArch64AsmPrinter::EmitJumpTableInfo() {
const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
if (!MJTI) return;
const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
if (JT.empty()) return;
const Function &F = MF->getFunction();
const TargetLoweringObjectFile &TLOF = getObjFileLowering();
bool JTInDiffSection =
!STI->isTargetCOFF() ||
!TLOF.shouldPutJumpTableInFunctionSection(
MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32,
F);
if (JTInDiffSection) {
// Drop it in the readonly section.
MCSection *ReadOnlySec = TLOF.getSectionForJumpTable(F, TM);
OutStreamer->SwitchSection(ReadOnlySec);
}
auto AFI = MF->getInfo<AArch64FunctionInfo>();
for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) {
const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs;
// If this jump table was deleted, ignore it.
if (JTBBs.empty()) continue;
unsigned Size = AFI->getJumpTableEntrySize(JTI);
EmitAlignment(Log2_32(Size));
OutStreamer->EmitLabel(GetJTISymbol(JTI));
for (auto *JTBB : JTBBs)
emitJumpTableEntry(MJTI, JTBB, JTI);
}
}
void AArch64AsmPrinter::emitJumpTableEntry(const MachineJumpTableInfo *MJTI,
const MachineBasicBlock *MBB,
unsigned JTI) {
const MCExpr *Value = MCSymbolRefExpr::create(MBB->getSymbol(), OutContext);
auto AFI = MF->getInfo<AArch64FunctionInfo>();
unsigned Size = AFI->getJumpTableEntrySize(JTI);
if (Size == 4) {
// .word LBB - LJTI
const TargetLowering *TLI = MF->getSubtarget().getTargetLowering();
const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF, JTI, OutContext);
Value = MCBinaryExpr::createSub(Value, Base, OutContext);
} else {
// .byte (LBB - LBB) >> 2 (or .hword)
const MCSymbol *BaseSym = AFI->getJumpTableEntryPCRelSymbol(JTI);
const MCExpr *Base = MCSymbolRefExpr::create(BaseSym, OutContext);
Value = MCBinaryExpr::createSub(Value, Base, OutContext);
Value = MCBinaryExpr::createLShr(
Value, MCConstantExpr::create(2, OutContext), OutContext);
}
OutStreamer->EmitValue(Value, Size);
}
/// Small jump tables contain an unsigned byte or half, representing the offset
/// from the lowest-addressed possible destination to the desired basic
/// block. Since all instructions are 4-byte aligned, this is further compressed
/// by counting in instructions rather than bytes (i.e. divided by 4). So, to
/// materialize the correct destination we need:
///
/// adr xDest, .LBB0_0
/// ldrb wScratch, [xTable, xEntry] (with "lsl #1" for ldrh).
/// add xDest, xDest, xScratch, lsl #2
void AArch64AsmPrinter::LowerJumpTableDestSmall(llvm::MCStreamer &OutStreamer,
const llvm::MachineInstr &MI) {
unsigned DestReg = MI.getOperand(0).getReg();
unsigned ScratchReg = MI.getOperand(1).getReg();
unsigned ScratchRegW =
STI->getRegisterInfo()->getSubReg(ScratchReg, AArch64::sub_32);
unsigned TableReg = MI.getOperand(2).getReg();
unsigned EntryReg = MI.getOperand(3).getReg();
int JTIdx = MI.getOperand(4).getIndex();
bool IsByteEntry = MI.getOpcode() == AArch64::JumpTableDest8;
// This has to be first because the compression pass based its reachability
// calculations on the start of the JumpTableDest instruction.
auto Label =
MF->getInfo<AArch64FunctionInfo>()->getJumpTableEntryPCRelSymbol(JTIdx);
EmitToStreamer(OutStreamer, MCInstBuilder(AArch64::ADR)
.addReg(DestReg)
.addExpr(MCSymbolRefExpr::create(
Label, MF->getContext())));
// Load the number of instruction-steps to offset from the label.
unsigned LdrOpcode = IsByteEntry ? AArch64::LDRBBroX : AArch64::LDRHHroX;
EmitToStreamer(OutStreamer, MCInstBuilder(LdrOpcode)
.addReg(ScratchRegW)
.addReg(TableReg)
.addReg(EntryReg)
.addImm(0)
.addImm(IsByteEntry ? 0 : 1));
// Multiply the steps by 4 and add to the already materialized base label
// address.
EmitToStreamer(OutStreamer, MCInstBuilder(AArch64::ADDXrs)
.addReg(DestReg)
.addReg(DestReg)
.addReg(ScratchReg)
.addImm(2));
}
void AArch64AsmPrinter::LowerSTACKMAP(MCStreamer &OutStreamer, StackMaps &SM,
const MachineInstr &MI) {
unsigned NumNOPBytes = StackMapOpers(&MI).getNumPatchBytes();
SM.recordStackMap(MI);
assert(NumNOPBytes % 4 == 0 && "Invalid number of NOP bytes requested!");
// Scan ahead to trim the shadow.
const MachineBasicBlock &MBB = *MI.getParent();
MachineBasicBlock::const_iterator MII(MI);
++MII;
while (NumNOPBytes > 0) {
if (MII == MBB.end() || MII->isCall() ||
MII->getOpcode() == AArch64::DBG_VALUE ||
MII->getOpcode() == TargetOpcode::PATCHPOINT ||
MII->getOpcode() == TargetOpcode::STACKMAP)
break;
++MII;
NumNOPBytes -= 4;
}
// Emit nops.
for (unsigned i = 0; i < NumNOPBytes; i += 4)
EmitToStreamer(OutStreamer, MCInstBuilder(AArch64::HINT).addImm(0));
}
// Lower a patchpoint of the form:
// [<def>], <id>, <numBytes>, <target>, <numArgs>
void AArch64AsmPrinter::LowerPATCHPOINT(MCStreamer &OutStreamer, StackMaps &SM,
const MachineInstr &MI) {
SM.recordPatchPoint(MI);
PatchPointOpers Opers(&MI);
int64_t CallTarget = Opers.getCallTarget().getImm();
unsigned EncodedBytes = 0;
if (CallTarget) {
assert((CallTarget & 0xFFFFFFFFFFFF) == CallTarget &&
"High 16 bits of call target should be zero.");
unsigned ScratchReg = MI.getOperand(Opers.getNextScratchIdx()).getReg();
EncodedBytes = 16;
// Materialize the jump address:
EmitToStreamer(OutStreamer, MCInstBuilder(AArch64::MOVZXi)
.addReg(ScratchReg)
.addImm((CallTarget >> 32) & 0xFFFF)
.addImm(32));
EmitToStreamer(OutStreamer, MCInstBuilder(AArch64::MOVKXi)
.addReg(ScratchReg)
.addReg(ScratchReg)
.addImm((CallTarget >> 16) & 0xFFFF)
.addImm(16));
EmitToStreamer(OutStreamer, MCInstBuilder(AArch64::MOVKXi)
.addReg(ScratchReg)
.addReg(ScratchReg)
.addImm(CallTarget & 0xFFFF)
.addImm(0));
EmitToStreamer(OutStreamer, MCInstBuilder(AArch64::BLR).addReg(ScratchReg));
}
// Emit padding.
unsigned NumBytes = Opers.getNumPatchBytes();
assert(NumBytes >= EncodedBytes &&
"Patchpoint can't request size less than the length of a call.");
assert((NumBytes - EncodedBytes) % 4 == 0 &&
"Invalid number of NOP bytes requested!");
for (unsigned i = EncodedBytes; i < NumBytes; i += 4)
EmitToStreamer(OutStreamer, MCInstBuilder(AArch64::HINT).addImm(0));
}
void AArch64AsmPrinter::EmitFMov0(const MachineInstr &MI) {
unsigned DestReg = MI.getOperand(0).getReg();
if (STI->hasZeroCycleZeroingFP() && !STI->hasZeroCycleZeroingFPWorkaround()) {
// Convert H/S/D register to corresponding Q register
if (AArch64::H0 <= DestReg && DestReg <= AArch64::H31)
DestReg = AArch64::Q0 + (DestReg - AArch64::H0);
else if (AArch64::S0 <= DestReg && DestReg <= AArch64::S31)
DestReg = AArch64::Q0 + (DestReg - AArch64::S0);
else {
assert(AArch64::D0 <= DestReg && DestReg <= AArch64::D31);
DestReg = AArch64::Q0 + (DestReg - AArch64::D0);
}
MCInst MOVI;
MOVI.setOpcode(AArch64::MOVIv2d_ns);
MOVI.addOperand(MCOperand::createReg(DestReg));
MOVI.addOperand(MCOperand::createImm(0));
EmitToStreamer(*OutStreamer, MOVI);
} else {
MCInst FMov;
switch (MI.getOpcode()) {
default: llvm_unreachable("Unexpected opcode");
case AArch64::FMOVH0:
FMov.setOpcode(AArch64::FMOVWHr);
FMov.addOperand(MCOperand::createReg(DestReg));
FMov.addOperand(MCOperand::createReg(AArch64::WZR));
break;
case AArch64::FMOVS0:
FMov.setOpcode(AArch64::FMOVWSr);
FMov.addOperand(MCOperand::createReg(DestReg));
FMov.addOperand(MCOperand::createReg(AArch64::WZR));
break;
case AArch64::FMOVD0:
FMov.setOpcode(AArch64::FMOVXDr);
FMov.addOperand(MCOperand::createReg(DestReg));
FMov.addOperand(MCOperand::createReg(AArch64::XZR));
break;
}
EmitToStreamer(*OutStreamer, FMov);
}
}
// Simple pseudo-instructions have their lowering (with expansion to real
// instructions) auto-generated.
#include "AArch64GenMCPseudoLowering.inc"
void AArch64AsmPrinter::EmitInstruction(const MachineInstr *MI) {
// Do any auto-generated pseudo lowerings.
if (emitPseudoExpansionLowering(*OutStreamer, MI))
return;
if (AArch64FI->getLOHRelated().count(MI)) {
// Generate a label for LOH related instruction
MCSymbol *LOHLabel = createTempSymbol("loh");
// Associate the instruction with the label
LOHInstToLabel[MI] = LOHLabel;
OutStreamer->EmitLabel(LOHLabel);
}
AArch64TargetStreamer *TS =
static_cast<AArch64TargetStreamer *>(OutStreamer->getTargetStreamer());
// Do any manual lowerings.
switch (MI->getOpcode()) {
default:
break;
case AArch64::MOVMCSym: {
unsigned DestReg = MI->getOperand(0).getReg();
const MachineOperand &MO_Sym = MI->getOperand(1);
MachineOperand Hi_MOSym(MO_Sym), Lo_MOSym(MO_Sym);
MCOperand Hi_MCSym, Lo_MCSym;
Hi_MOSym.setTargetFlags(AArch64II::MO_G1 | AArch64II::MO_S);
Lo_MOSym.setTargetFlags(AArch64II::MO_G0 | AArch64II::MO_NC);
MCInstLowering.lowerOperand(Hi_MOSym, Hi_MCSym);
MCInstLowering.lowerOperand(Lo_MOSym, Lo_MCSym);
MCInst MovZ;
MovZ.setOpcode(AArch64::MOVZXi);
MovZ.addOperand(MCOperand::createReg(DestReg));
MovZ.addOperand(Hi_MCSym);
MovZ.addOperand(MCOperand::createImm(16));
EmitToStreamer(*OutStreamer, MovZ);
MCInst MovK;
MovK.setOpcode(AArch64::MOVKXi);
MovK.addOperand(MCOperand::createReg(DestReg));
MovK.addOperand(MCOperand::createReg(DestReg));
MovK.addOperand(Lo_MCSym);
MovK.addOperand(MCOperand::createImm(0));
EmitToStreamer(*OutStreamer, MovK);
return;
}
case AArch64::MOVIv2d_ns:
// If the target has <rdar://problem/16473581>, lower this
// instruction to movi.16b instead.
if (STI->hasZeroCycleZeroingFPWorkaround() &&
MI->getOperand(1).getImm() == 0) {
MCInst TmpInst;
TmpInst.setOpcode(AArch64::MOVIv16b_ns);
TmpInst.addOperand(MCOperand::createReg(MI->getOperand(0).getReg()));
TmpInst.addOperand(MCOperand::createImm(MI->getOperand(1).getImm()));
EmitToStreamer(*OutStreamer, TmpInst);
return;
}
break;
case AArch64::DBG_VALUE: {
if (isVerbose() && OutStreamer->hasRawTextSupport()) {
SmallString<128> TmpStr;
raw_svector_ostream OS(TmpStr);
PrintDebugValueComment(MI, OS);
OutStreamer->EmitRawText(StringRef(OS.str()));
}
return;
case AArch64::EMITBKEY: {
ExceptionHandling ExceptionHandlingType = MAI->getExceptionHandlingType();
if (ExceptionHandlingType != ExceptionHandling::DwarfCFI &&
ExceptionHandlingType != ExceptionHandling::ARM)
return;
if (needsCFIMoves() == CFI_M_None)
return;
OutStreamer->EmitCFIBKeyFrame();
return;
}
}
// Tail calls use pseudo instructions so they have the proper code-gen
// attributes (isCall, isReturn, etc.). We lower them to the real
// instruction here.
case AArch64::TCRETURNri:
case AArch64::TCRETURNriBTI:
case AArch64::TCRETURNriALL: {
MCInst TmpInst;
TmpInst.setOpcode(AArch64::BR);
TmpInst.addOperand(MCOperand::createReg(MI->getOperand(0).getReg()));
EmitToStreamer(*OutStreamer, TmpInst);
return;
}
case AArch64::TCRETURNdi: {
MCOperand Dest;
MCInstLowering.lowerOperand(MI->getOperand(0), Dest);
MCInst TmpInst;
TmpInst.setOpcode(AArch64::B);
TmpInst.addOperand(Dest);
EmitToStreamer(*OutStreamer, TmpInst);
return;
}
case AArch64::TLSDESC_CALLSEQ: {
/// lower this to:
/// adrp x0, :tlsdesc:var
/// ldr x1, [x0, #:tlsdesc_lo12:var]
/// add x0, x0, #:tlsdesc_lo12:var
/// .tlsdesccall var
/// blr x1
/// (TPIDR_EL0 offset now in x0)
const MachineOperand &MO_Sym = MI->getOperand(0);
MachineOperand MO_TLSDESC_LO12(MO_Sym), MO_TLSDESC(MO_Sym);
MCOperand Sym, SymTLSDescLo12, SymTLSDesc;
MO_TLSDESC_LO12.setTargetFlags(AArch64II::MO_TLS | AArch64II::MO_PAGEOFF);
MO_TLSDESC.setTargetFlags(AArch64II::MO_TLS | AArch64II::MO_PAGE);
MCInstLowering.lowerOperand(MO_Sym, Sym);
MCInstLowering.lowerOperand(MO_TLSDESC_LO12, SymTLSDescLo12);
MCInstLowering.lowerOperand(MO_TLSDESC, SymTLSDesc);
MCInst Adrp;
Adrp.setOpcode(AArch64::ADRP);
Adrp.addOperand(MCOperand::createReg(AArch64::X0));
Adrp.addOperand(SymTLSDesc);
EmitToStreamer(*OutStreamer, Adrp);
MCInst Ldr;
Ldr.setOpcode(AArch64::LDRXui);
Ldr.addOperand(MCOperand::createReg(AArch64::X1));
Ldr.addOperand(MCOperand::createReg(AArch64::X0));
Ldr.addOperand(SymTLSDescLo12);
Ldr.addOperand(MCOperand::createImm(0));
EmitToStreamer(*OutStreamer, Ldr);
MCInst Add;
Add.setOpcode(AArch64::ADDXri);
Add.addOperand(MCOperand::createReg(AArch64::X0));
Add.addOperand(MCOperand::createReg(AArch64::X0));
Add.addOperand(SymTLSDescLo12);
Add.addOperand(MCOperand::createImm(AArch64_AM::getShiftValue(0)));
EmitToStreamer(*OutStreamer, Add);
// Emit a relocation-annotation. This expands to no code, but requests
// the following instruction gets an R_AARCH64_TLSDESC_CALL.
MCInst TLSDescCall;
TLSDescCall.setOpcode(AArch64::TLSDESCCALL);
TLSDescCall.addOperand(Sym);
EmitToStreamer(*OutStreamer, TLSDescCall);
MCInst Blr;
Blr.setOpcode(AArch64::BLR);
Blr.addOperand(MCOperand::createReg(AArch64::X1));
EmitToStreamer(*OutStreamer, Blr);
return;
}
case AArch64::JumpTableDest32: {
// We want:
// ldrsw xScratch, [xTable, xEntry, lsl #2]
// add xDest, xTable, xScratch
unsigned DestReg = MI->getOperand(0).getReg(),
ScratchReg = MI->getOperand(1).getReg(),
TableReg = MI->getOperand(2).getReg(),
EntryReg = MI->getOperand(3).getReg();
EmitToStreamer(*OutStreamer, MCInstBuilder(AArch64::LDRSWroX)
.addReg(ScratchReg)
.addReg(TableReg)
.addReg(EntryReg)
.addImm(0)
.addImm(1));
EmitToStreamer(*OutStreamer, MCInstBuilder(AArch64::ADDXrs)
.addReg(DestReg)
.addReg(TableReg)
.addReg(ScratchReg)
.addImm(0));
return;
}
case AArch64::JumpTableDest16:
case AArch64::JumpTableDest8:
LowerJumpTableDestSmall(*OutStreamer, *MI);
return;
case AArch64::FMOVH0:
case AArch64::FMOVS0:
case AArch64::FMOVD0:
EmitFMov0(*MI);
return;
case TargetOpcode::STACKMAP:
return LowerSTACKMAP(*OutStreamer, SM, *MI);
case TargetOpcode::PATCHPOINT:
return LowerPATCHPOINT(*OutStreamer, SM, *MI);
case TargetOpcode::PATCHABLE_FUNCTION_ENTER:
LowerPATCHABLE_FUNCTION_ENTER(*MI);
return;
case TargetOpcode::PATCHABLE_FUNCTION_EXIT:
LowerPATCHABLE_FUNCTION_EXIT(*MI);
return;
case TargetOpcode::PATCHABLE_TAIL_CALL:
LowerPATCHABLE_TAIL_CALL(*MI);
return;
case AArch64::HWASAN_CHECK_MEMACCESS:
LowerHWASAN_CHECK_MEMACCESS(*MI);
return;
case AArch64::SEH_StackAlloc:
TS->EmitARM64WinCFIAllocStack(MI->getOperand(0).getImm());
return;
case AArch64::SEH_SaveFPLR:
TS->EmitARM64WinCFISaveFPLR(MI->getOperand(0).getImm());
return;
case AArch64::SEH_SaveFPLR_X:
assert(MI->getOperand(0).getImm() < 0 &&
"Pre increment SEH opcode must have a negative offset");
TS->EmitARM64WinCFISaveFPLRX(-MI->getOperand(0).getImm());
return;
case AArch64::SEH_SaveReg:
TS->EmitARM64WinCFISaveReg(MI->getOperand(0).getImm(),
MI->getOperand(1).getImm());
return;
case AArch64::SEH_SaveReg_X:
assert(MI->getOperand(1).getImm() < 0 &&
"Pre increment SEH opcode must have a negative offset");
TS->EmitARM64WinCFISaveRegX(MI->getOperand(0).getImm(),
-MI->getOperand(1).getImm());
return;
case AArch64::SEH_SaveRegP:
assert((MI->getOperand(1).getImm() - MI->getOperand(0).getImm() == 1) &&
"Non-consecutive registers not allowed for save_regp");
TS->EmitARM64WinCFISaveRegP(MI->getOperand(0).getImm(),
MI->getOperand(2).getImm());
return;
case AArch64::SEH_SaveRegP_X:
assert((MI->getOperand(1).getImm() - MI->getOperand(0).getImm() == 1) &&
"Non-consecutive registers not allowed for save_regp_x");
assert(MI->getOperand(2).getImm() < 0 &&
"Pre increment SEH opcode must have a negative offset");
TS->EmitARM64WinCFISaveRegPX(MI->getOperand(0).getImm(),
-MI->getOperand(2).getImm());
return;
case AArch64::SEH_SaveFReg:
TS->EmitARM64WinCFISaveFReg(MI->getOperand(0).getImm(),
MI->getOperand(1).getImm());
return;
case AArch64::SEH_SaveFReg_X:
assert(MI->getOperand(1).getImm() < 0 &&
"Pre increment SEH opcode must have a negative offset");
TS->EmitARM64WinCFISaveFRegX(MI->getOperand(0).getImm(),
-MI->getOperand(1).getImm());
return;
case AArch64::SEH_SaveFRegP:
assert((MI->getOperand(1).getImm() - MI->getOperand(0).getImm() == 1) &&
"Non-consecutive registers not allowed for save_regp");
TS->EmitARM64WinCFISaveFRegP(MI->getOperand(0).getImm(),
MI->getOperand(2).getImm());
return;
case AArch64::SEH_SaveFRegP_X:
assert((MI->getOperand(1).getImm() - MI->getOperand(0).getImm() == 1) &&
"Non-consecutive registers not allowed for save_regp_x");
assert(MI->getOperand(2).getImm() < 0 &&
"Pre increment SEH opcode must have a negative offset");
TS->EmitARM64WinCFISaveFRegPX(MI->getOperand(0).getImm(),
-MI->getOperand(2).getImm());
return;
case AArch64::SEH_SetFP:
TS->EmitARM64WinCFISetFP();
return;
case AArch64::SEH_AddFP:
TS->EmitARM64WinCFIAddFP(MI->getOperand(0).getImm());
return;
case AArch64::SEH_Nop:
TS->EmitARM64WinCFINop();
return;
case AArch64::SEH_PrologEnd:
TS->EmitARM64WinCFIPrologEnd();
return;
case AArch64::SEH_EpilogStart:
TS->EmitARM64WinCFIEpilogStart();
return;
case AArch64::SEH_EpilogEnd:
TS->EmitARM64WinCFIEpilogEnd();
return;
}
// Finally, do the automated lowerings for everything else.
MCInst TmpInst;
MCInstLowering.Lower(MI, TmpInst);
EmitToStreamer(*OutStreamer, TmpInst);
}
// Force static initialization.
extern "C" void LLVMInitializeAArch64AsmPrinter() {
RegisterAsmPrinter<AArch64AsmPrinter> X(getTheAArch64leTarget());
RegisterAsmPrinter<AArch64AsmPrinter> Y(getTheAArch64beTarget());
RegisterAsmPrinter<AArch64AsmPrinter> Z(getTheARM64Target());
}
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