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llvm-project/llvm/lib/Target/X86/X86CodeEmitter.cpp

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//===-- X86CodeEmitter.cpp - Convert X86 code to machine code -------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file contains the pass that transforms the X86 machine instructions into
// relocatable machine code.
//
//===----------------------------------------------------------------------===//
#define DEBUG_TYPE "x86-emitter"
#include "X86InstrInfo.h"
#include "X86JITInfo.h"
#include "X86Subtarget.h"
#include "X86TargetMachine.h"
#include "X86Relocations.h"
#include "X86.h"
#include "llvm/LLVMContext.h"
#include "llvm/PassManager.h"
#include "llvm/CodeGen/JITCodeEmitter.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineInstr.h"
#include "llvm/CodeGen/MachineModuleInfo.h"
#include "llvm/CodeGen/Passes.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/MC/MCCodeEmitter.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCInst.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Target/TargetOptions.h"
using namespace llvm;
STATISTIC(NumEmitted, "Number of machine instructions emitted");
namespace {
template<class CodeEmitter>
class Emitter : public MachineFunctionPass {
const X86InstrInfo *II;
const DataLayout *TD;
X86TargetMachine &TM;
CodeEmitter &MCE;
MachineModuleInfo *MMI;
intptr_t PICBaseOffset;
bool Is64BitMode;
bool IsPIC;
public:
static char ID;
explicit Emitter(X86TargetMachine &tm, CodeEmitter &mce)
: MachineFunctionPass(ID), II(0), TD(0), TM(tm),
MCE(mce), PICBaseOffset(0), Is64BitMode(false),
IsPIC(TM.getRelocationModel() == Reloc::PIC_) {}
Emitter(X86TargetMachine &tm, CodeEmitter &mce,
const X86InstrInfo &ii, const DataLayout &td, bool is64)
: MachineFunctionPass(ID), II(&ii), TD(&td), TM(tm),
MCE(mce), PICBaseOffset(0), Is64BitMode(is64),
IsPIC(TM.getRelocationModel() == Reloc::PIC_) {}
bool runOnMachineFunction(MachineFunction &MF);
virtual const char *getPassName() const {
return "X86 Machine Code Emitter";
}
void emitOpcodePrefix(uint64_t TSFlags, int MemOperand,
const MachineInstr &MI,
const MCInstrDesc *Desc) const;
void emitVEXOpcodePrefix(uint64_t TSFlags, int MemOperand,
const MachineInstr &MI,
const MCInstrDesc *Desc) const;
void emitSegmentOverridePrefix(uint64_t TSFlags,
int MemOperand,
const MachineInstr &MI) const;
void emitInstruction(MachineInstr &MI, const MCInstrDesc *Desc);
void getAnalysisUsage(AnalysisUsage &AU) const {
AU.setPreservesAll();
AU.addRequired<MachineModuleInfo>();
MachineFunctionPass::getAnalysisUsage(AU);
}
private:
void emitPCRelativeBlockAddress(MachineBasicBlock *MBB);
void emitGlobalAddress(const GlobalValue *GV, unsigned Reloc,
intptr_t Disp = 0, intptr_t PCAdj = 0,
bool Indirect = false);
void emitExternalSymbolAddress(const char *ES, unsigned Reloc);
void emitConstPoolAddress(unsigned CPI, unsigned Reloc, intptr_t Disp = 0,
intptr_t PCAdj = 0);
void emitJumpTableAddress(unsigned JTI, unsigned Reloc,
intptr_t PCAdj = 0);
void emitDisplacementField(const MachineOperand *RelocOp, int DispVal,
intptr_t Adj = 0, bool IsPCRel = true);
void emitRegModRMByte(unsigned ModRMReg, unsigned RegOpcodeField);
void emitRegModRMByte(unsigned RegOpcodeField);
void emitSIBByte(unsigned SS, unsigned Index, unsigned Base);
void emitConstant(uint64_t Val, unsigned Size);
void emitMemModRMByte(const MachineInstr &MI,
unsigned Op, unsigned RegOpcodeField,
intptr_t PCAdj = 0);
unsigned getX86RegNum(unsigned RegNo) const {
const TargetRegisterInfo *TRI = TM.getRegisterInfo();
return TRI->getEncodingValue(RegNo) & 0x7;
}
unsigned char getVEXRegisterEncoding(const MachineInstr &MI,
unsigned OpNum) const;
};
template<class CodeEmitter>
char Emitter<CodeEmitter>::ID = 0;
} // end anonymous namespace.
/// createX86CodeEmitterPass - Return a pass that emits the collected X86 code
/// to the specified templated MachineCodeEmitter object.
FunctionPass *llvm::createX86JITCodeEmitterPass(X86TargetMachine &TM,
JITCodeEmitter &JCE) {
return new Emitter<JITCodeEmitter>(TM, JCE);
}
template<class CodeEmitter>
bool Emitter<CodeEmitter>::runOnMachineFunction(MachineFunction &MF) {
MMI = &getAnalysis<MachineModuleInfo>();
MCE.setModuleInfo(MMI);
II = TM.getInstrInfo();
TD = TM.getDataLayout();
Is64BitMode = TM.getSubtarget<X86Subtarget>().is64Bit();
IsPIC = TM.getRelocationModel() == Reloc::PIC_;
do {
DEBUG(dbgs() << "JITTing function '" << MF.getName() << "'\n");
MCE.startFunction(MF);
for (MachineFunction::iterator MBB = MF.begin(), E = MF.end();
MBB != E; ++MBB) {
MCE.StartMachineBasicBlock(MBB);
for (MachineBasicBlock::iterator I = MBB->begin(), E = MBB->end();
I != E; ++I) {
const MCInstrDesc &Desc = I->getDesc();
emitInstruction(*I, &Desc);
// MOVPC32r is basically a call plus a pop instruction.
if (Desc.getOpcode() == X86::MOVPC32r)
emitInstruction(*I, &II->get(X86::POP32r));
++NumEmitted; // Keep track of the # of mi's emitted
}
}
} while (MCE.finishFunction(MF));
return false;
}
/// determineREX - Determine if the MachineInstr has to be encoded with a X86-64
/// REX prefix which specifies 1) 64-bit instructions, 2) non-default operand
/// size, and 3) use of X86-64 extended registers.
static unsigned determineREX(const MachineInstr &MI) {
unsigned REX = 0;
const MCInstrDesc &Desc = MI.getDesc();
// Pseudo instructions do not need REX prefix byte.
if ((Desc.TSFlags & X86II::FormMask) == X86II::Pseudo)
return 0;
if (Desc.TSFlags & X86II::REX_W)
REX |= 1 << 3;
unsigned NumOps = Desc.getNumOperands();
if (NumOps) {
bool isTwoAddr = NumOps > 1 &&
Desc.getOperandConstraint(1, MCOI::TIED_TO) != -1;
// If it accesses SPL, BPL, SIL, or DIL, then it requires a 0x40 REX prefix.
unsigned i = isTwoAddr ? 1 : 0;
for (unsigned e = NumOps; i != e; ++i) {
const MachineOperand& MO = MI.getOperand(i);
if (MO.isReg()) {
unsigned Reg = MO.getReg();
if (X86II::isX86_64NonExtLowByteReg(Reg))
REX |= 0x40;
}
}
switch (Desc.TSFlags & X86II::FormMask) {
case X86II::MRMInitReg:
if (X86InstrInfo::isX86_64ExtendedReg(MI.getOperand(0)))
REX |= (1 << 0) | (1 << 2);
break;
case X86II::MRMSrcReg: {
if (X86InstrInfo::isX86_64ExtendedReg(MI.getOperand(0)))
REX |= 1 << 2;
i = isTwoAddr ? 2 : 1;
for (unsigned e = NumOps; i != e; ++i) {
const MachineOperand& MO = MI.getOperand(i);
if (X86InstrInfo::isX86_64ExtendedReg(MO))
REX |= 1 << 0;
}
break;
}
case X86II::MRMSrcMem: {
if (X86InstrInfo::isX86_64ExtendedReg(MI.getOperand(0)))
REX |= 1 << 2;
unsigned Bit = 0;
i = isTwoAddr ? 2 : 1;
for (; i != NumOps; ++i) {
const MachineOperand& MO = MI.getOperand(i);
if (MO.isReg()) {
if (X86InstrInfo::isX86_64ExtendedReg(MO))
REX |= 1 << Bit;
Bit++;
}
}
break;
}
case X86II::MRM0m: case X86II::MRM1m:
case X86II::MRM2m: case X86II::MRM3m:
case X86II::MRM4m: case X86II::MRM5m:
case X86II::MRM6m: case X86II::MRM7m:
case X86II::MRMDestMem: {
unsigned e = (isTwoAddr ? X86::AddrNumOperands+1 : X86::AddrNumOperands);
i = isTwoAddr ? 1 : 0;
if (NumOps > e && X86InstrInfo::isX86_64ExtendedReg(MI.getOperand(e)))
REX |= 1 << 2;
unsigned Bit = 0;
for (; i != e; ++i) {
const MachineOperand& MO = MI.getOperand(i);
if (MO.isReg()) {
if (X86InstrInfo::isX86_64ExtendedReg(MO))
REX |= 1 << Bit;
Bit++;
}
}
break;
}
default: {
if (X86InstrInfo::isX86_64ExtendedReg(MI.getOperand(0)))
REX |= 1 << 0;
i = isTwoAddr ? 2 : 1;
for (unsigned e = NumOps; i != e; ++i) {
const MachineOperand& MO = MI.getOperand(i);
if (X86InstrInfo::isX86_64ExtendedReg(MO))
REX |= 1 << 2;
}
break;
}
}
}
return REX;
}
/// emitPCRelativeBlockAddress - This method keeps track of the information
/// necessary to resolve the address of this block later and emits a dummy
/// value.
///
template<class CodeEmitter>
void Emitter<CodeEmitter>::emitPCRelativeBlockAddress(MachineBasicBlock *MBB) {
// Remember where this reference was and where it is to so we can
// deal with it later.
MCE.addRelocation(MachineRelocation::getBB(MCE.getCurrentPCOffset(),
X86::reloc_pcrel_word, MBB));
MCE.emitWordLE(0);
}
/// emitGlobalAddress - Emit the specified address to the code stream assuming
/// this is part of a "take the address of a global" instruction.
///
template<class CodeEmitter>
void Emitter<CodeEmitter>::emitGlobalAddress(const GlobalValue *GV,
unsigned Reloc,
intptr_t Disp /* = 0 */,
intptr_t PCAdj /* = 0 */,
bool Indirect /* = false */) {
intptr_t RelocCST = Disp;
if (Reloc == X86::reloc_picrel_word)
RelocCST = PICBaseOffset;
else if (Reloc == X86::reloc_pcrel_word)
RelocCST = PCAdj;
MachineRelocation MR = Indirect
? MachineRelocation::getIndirectSymbol(MCE.getCurrentPCOffset(), Reloc,
const_cast<GlobalValue *>(GV),
RelocCST, false)
: MachineRelocation::getGV(MCE.getCurrentPCOffset(), Reloc,
const_cast<GlobalValue *>(GV), RelocCST, false);
MCE.addRelocation(MR);
// The relocated value will be added to the displacement
if (Reloc == X86::reloc_absolute_dword)
MCE.emitDWordLE(Disp);
else
MCE.emitWordLE((int32_t)Disp);
}
/// emitExternalSymbolAddress - Arrange for the address of an external symbol to
/// be emitted to the current location in the function, and allow it to be PC
/// relative.
template<class CodeEmitter>
void Emitter<CodeEmitter>::emitExternalSymbolAddress(const char *ES,
unsigned Reloc) {
intptr_t RelocCST = (Reloc == X86::reloc_picrel_word) ? PICBaseOffset : 0;
// X86 never needs stubs because instruction selection will always pick
// an instruction sequence that is large enough to hold any address
// to a symbol.
// (see X86ISelLowering.cpp, near 2039: X86TargetLowering::LowerCall)
bool NeedStub = false;
MCE.addRelocation(MachineRelocation::getExtSym(MCE.getCurrentPCOffset(),
Reloc, ES, RelocCST,
0, NeedStub));
if (Reloc == X86::reloc_absolute_dword)
MCE.emitDWordLE(0);
else
MCE.emitWordLE(0);
}
/// emitConstPoolAddress - Arrange for the address of an constant pool
/// to be emitted to the current location in the function, and allow it to be PC
/// relative.
template<class CodeEmitter>
void Emitter<CodeEmitter>::emitConstPoolAddress(unsigned CPI, unsigned Reloc,
intptr_t Disp /* = 0 */,
intptr_t PCAdj /* = 0 */) {
intptr_t RelocCST = 0;
if (Reloc == X86::reloc_picrel_word)
RelocCST = PICBaseOffset;
else if (Reloc == X86::reloc_pcrel_word)
RelocCST = PCAdj;
MCE.addRelocation(MachineRelocation::getConstPool(MCE.getCurrentPCOffset(),
Reloc, CPI, RelocCST));
// The relocated value will be added to the displacement
if (Reloc == X86::reloc_absolute_dword)
MCE.emitDWordLE(Disp);
else
MCE.emitWordLE((int32_t)Disp);
}
/// emitJumpTableAddress - Arrange for the address of a jump table to
/// be emitted to the current location in the function, and allow it to be PC
/// relative.
template<class CodeEmitter>
void Emitter<CodeEmitter>::emitJumpTableAddress(unsigned JTI, unsigned Reloc,
intptr_t PCAdj /* = 0 */) {
intptr_t RelocCST = 0;
if (Reloc == X86::reloc_picrel_word)
RelocCST = PICBaseOffset;
else if (Reloc == X86::reloc_pcrel_word)
RelocCST = PCAdj;
MCE.addRelocation(MachineRelocation::getJumpTable(MCE.getCurrentPCOffset(),
Reloc, JTI, RelocCST));
// The relocated value will be added to the displacement
if (Reloc == X86::reloc_absolute_dword)
MCE.emitDWordLE(0);
else
MCE.emitWordLE(0);
}
inline static unsigned char ModRMByte(unsigned Mod, unsigned RegOpcode,
unsigned RM) {
assert(Mod < 4 && RegOpcode < 8 && RM < 8 && "ModRM Fields out of range!");
return RM | (RegOpcode << 3) | (Mod << 6);
}
template<class CodeEmitter>
void Emitter<CodeEmitter>::emitRegModRMByte(unsigned ModRMReg,
unsigned RegOpcodeFld){
MCE.emitByte(ModRMByte(3, RegOpcodeFld, getX86RegNum(ModRMReg)));
}
template<class CodeEmitter>
void Emitter<CodeEmitter>::emitRegModRMByte(unsigned RegOpcodeFld) {
MCE.emitByte(ModRMByte(3, RegOpcodeFld, 0));
}
template<class CodeEmitter>
void Emitter<CodeEmitter>::emitSIBByte(unsigned SS,
unsigned Index,
unsigned Base) {
// SIB byte is in the same format as the ModRMByte...
MCE.emitByte(ModRMByte(SS, Index, Base));
}
template<class CodeEmitter>
void Emitter<CodeEmitter>::emitConstant(uint64_t Val, unsigned Size) {
// Output the constant in little endian byte order...
for (unsigned i = 0; i != Size; ++i) {
MCE.emitByte(Val & 255);
Val >>= 8;
}
}
/// isDisp8 - Return true if this signed displacement fits in a 8-bit
/// sign-extended field.
static bool isDisp8(int Value) {
return Value == (signed char)Value;
}
static bool gvNeedsNonLazyPtr(const MachineOperand &GVOp,
const TargetMachine &TM) {
// For Darwin-64, simulate the linktime GOT by using the same non-lazy-pointer
// mechanism as 32-bit mode.
if (TM.getSubtarget<X86Subtarget>().is64Bit() &&
!TM.getSubtarget<X86Subtarget>().isTargetDarwin())
return false;
// Return true if this is a reference to a stub containing the address of the
// global, not the global itself.
return isGlobalStubReference(GVOp.getTargetFlags());
}
template<class CodeEmitter>
void Emitter<CodeEmitter>::emitDisplacementField(const MachineOperand *RelocOp,
int DispVal,
intptr_t Adj /* = 0 */,
bool IsPCRel /* = true */) {
// If this is a simple integer displacement that doesn't require a relocation,
// emit it now.
if (!RelocOp) {
emitConstant(DispVal, 4);
return;
}
// Otherwise, this is something that requires a relocation. Emit it as such
// now.
unsigned RelocType = Is64BitMode ?
(IsPCRel ? X86::reloc_pcrel_word : X86::reloc_absolute_word_sext)
: (IsPIC ? X86::reloc_picrel_word : X86::reloc_absolute_word);
if (RelocOp->isGlobal()) {
// In 64-bit static small code model, we could potentially emit absolute.
// But it's probably not beneficial. If the MCE supports using RIP directly
// do it, otherwise fallback to absolute (this is determined by IsPCRel).
// 89 05 00 00 00 00 mov %eax,0(%rip) # PC-relative
// 89 04 25 00 00 00 00 mov %eax,0x0 # Absolute
bool Indirect = gvNeedsNonLazyPtr(*RelocOp, TM);
emitGlobalAddress(RelocOp->getGlobal(), RelocType, RelocOp->getOffset(),
Adj, Indirect);
} else if (RelocOp->isSymbol()) {
emitExternalSymbolAddress(RelocOp->getSymbolName(), RelocType);
} else if (RelocOp->isCPI()) {
emitConstPoolAddress(RelocOp->getIndex(), RelocType,
RelocOp->getOffset(), Adj);
} else {
assert(RelocOp->isJTI() && "Unexpected machine operand!");
emitJumpTableAddress(RelocOp->getIndex(), RelocType, Adj);
}
}
template<class CodeEmitter>
void Emitter<CodeEmitter>::emitMemModRMByte(const MachineInstr &MI,
unsigned Op,unsigned RegOpcodeField,
intptr_t PCAdj) {
const MachineOperand &Op3 = MI.getOperand(Op+3);
int DispVal = 0;
const MachineOperand *DispForReloc = 0;
// Figure out what sort of displacement we have to handle here.
if (Op3.isGlobal()) {
DispForReloc = &Op3;
} else if (Op3.isSymbol()) {
DispForReloc = &Op3;
} else if (Op3.isCPI()) {
if (!MCE.earlyResolveAddresses() || Is64BitMode || IsPIC) {
DispForReloc = &Op3;
} else {
DispVal += MCE.getConstantPoolEntryAddress(Op3.getIndex());
DispVal += Op3.getOffset();
}
} else if (Op3.isJTI()) {
if (!MCE.earlyResolveAddresses() || Is64BitMode || IsPIC) {
DispForReloc = &Op3;
} else {
DispVal += MCE.getJumpTableEntryAddress(Op3.getIndex());
}
} else {
DispVal = Op3.getImm();
}
const MachineOperand &Base = MI.getOperand(Op);
const MachineOperand &Scale = MI.getOperand(Op+1);
const MachineOperand &IndexReg = MI.getOperand(Op+2);
unsigned BaseReg = Base.getReg();
// Handle %rip relative addressing.
if (BaseReg == X86::RIP ||
(Is64BitMode && DispForReloc)) { // [disp32+RIP] in X86-64 mode
assert(IndexReg.getReg() == 0 && Is64BitMode &&
"Invalid rip-relative address");
MCE.emitByte(ModRMByte(0, RegOpcodeField, 5));
emitDisplacementField(DispForReloc, DispVal, PCAdj, true);
return;
}
// Indicate that the displacement will use an pcrel or absolute reference
// by default. MCEs able to resolve addresses on-the-fly use pcrel by default
// while others, unless explicit asked to use RIP, use absolute references.
bool IsPCRel = MCE.earlyResolveAddresses() ? true : false;
// Is a SIB byte needed?
// If no BaseReg, issue a RIP relative instruction only if the MCE can
// resolve addresses on-the-fly, otherwise use SIB (Intel Manual 2A, table
// 2-7) and absolute references.
unsigned BaseRegNo = -1U;
if (BaseReg != 0 && BaseReg != X86::RIP)
BaseRegNo = getX86RegNum(BaseReg);
if (// The SIB byte must be used if there is an index register.
IndexReg.getReg() == 0 &&
// The SIB byte must be used if the base is ESP/RSP/R12, all of which
// encode to an R/M value of 4, which indicates that a SIB byte is
// present.
BaseRegNo != N86::ESP &&
// If there is no base register and we're in 64-bit mode, we need a SIB
// byte to emit an addr that is just 'disp32' (the non-RIP relative form).
(!Is64BitMode || BaseReg != 0)) {
if (BaseReg == 0 || // [disp32] in X86-32 mode
BaseReg == X86::RIP) { // [disp32+RIP] in X86-64 mode
MCE.emitByte(ModRMByte(0, RegOpcodeField, 5));
emitDisplacementField(DispForReloc, DispVal, PCAdj, true);
return;
}
// If the base is not EBP/ESP and there is no displacement, use simple
// indirect register encoding, this handles addresses like [EAX]. The
// encoding for [EBP] with no displacement means [disp32] so we handle it
// by emitting a displacement of 0 below.
if (!DispForReloc && DispVal == 0 && BaseRegNo != N86::EBP) {
MCE.emitByte(ModRMByte(0, RegOpcodeField, BaseRegNo));
return;
}
// Otherwise, if the displacement fits in a byte, encode as [REG+disp8].
if (!DispForReloc && isDisp8(DispVal)) {
MCE.emitByte(ModRMByte(1, RegOpcodeField, BaseRegNo));
emitConstant(DispVal, 1);
return;
}
// Otherwise, emit the most general non-SIB encoding: [REG+disp32]
MCE.emitByte(ModRMByte(2, RegOpcodeField, BaseRegNo));
emitDisplacementField(DispForReloc, DispVal, PCAdj, IsPCRel);
return;
}
// Otherwise we need a SIB byte, so start by outputting the ModR/M byte first.
assert(IndexReg.getReg() != X86::ESP &&
IndexReg.getReg() != X86::RSP && "Cannot use ESP as index reg!");
bool ForceDisp32 = false;
bool ForceDisp8 = false;
if (BaseReg == 0) {
// If there is no base register, we emit the special case SIB byte with
// MOD=0, BASE=4, to JUST get the index, scale, and displacement.
MCE.emitByte(ModRMByte(0, RegOpcodeField, 4));
ForceDisp32 = true;
} else if (DispForReloc) {
// Emit the normal disp32 encoding.
MCE.emitByte(ModRMByte(2, RegOpcodeField, 4));
ForceDisp32 = true;
} else if (DispVal == 0 && BaseRegNo != N86::EBP) {
// Emit no displacement ModR/M byte
MCE.emitByte(ModRMByte(0, RegOpcodeField, 4));
} else if (isDisp8(DispVal)) {
// Emit the disp8 encoding...
MCE.emitByte(ModRMByte(1, RegOpcodeField, 4));
ForceDisp8 = true; // Make sure to force 8 bit disp if Base=EBP
} else {
// Emit the normal disp32 encoding...
MCE.emitByte(ModRMByte(2, RegOpcodeField, 4));
}
// Calculate what the SS field value should be...
static const unsigned SSTable[] = { ~0U, 0, 1, ~0U, 2, ~0U, ~0U, ~0U, 3 };
unsigned SS = SSTable[Scale.getImm()];
if (BaseReg == 0) {
// Handle the SIB byte for the case where there is no base, see Intel
// Manual 2A, table 2-7. The displacement has already been output.
unsigned IndexRegNo;
if (IndexReg.getReg())
IndexRegNo = getX86RegNum(IndexReg.getReg());
else // Examples: [ESP+1*<noreg>+4] or [scaled idx]+disp32 (MOD=0,BASE=5)
IndexRegNo = 4;
emitSIBByte(SS, IndexRegNo, 5);
} else {
unsigned BaseRegNo = getX86RegNum(BaseReg);
unsigned IndexRegNo;
if (IndexReg.getReg())
IndexRegNo = getX86RegNum(IndexReg.getReg());
else
IndexRegNo = 4; // For example [ESP+1*<noreg>+4]
emitSIBByte(SS, IndexRegNo, BaseRegNo);
}
// Do we need to output a displacement?
if (ForceDisp8) {
emitConstant(DispVal, 1);
} else if (DispVal != 0 || ForceDisp32) {
emitDisplacementField(DispForReloc, DispVal, PCAdj, IsPCRel);
}
}
static const MCInstrDesc *UpdateOp(MachineInstr &MI, const X86InstrInfo *II,
unsigned Opcode) {
const MCInstrDesc *Desc = &II->get(Opcode);
MI.setDesc(*Desc);
return Desc;
}
/// Is16BitMemOperand - Return true if the specified instruction has
/// a 16-bit memory operand. Op specifies the operand # of the memoperand.
static bool Is16BitMemOperand(const MachineInstr &MI, unsigned Op) {
const MachineOperand &BaseReg = MI.getOperand(Op+X86::AddrBaseReg);
const MachineOperand &IndexReg = MI.getOperand(Op+X86::AddrIndexReg);
if ((BaseReg.getReg() != 0 &&
X86MCRegisterClasses[X86::GR16RegClassID].contains(BaseReg.getReg())) ||
(IndexReg.getReg() != 0 &&
X86MCRegisterClasses[X86::GR16RegClassID].contains(IndexReg.getReg())))
return true;
return false;
}
/// Is32BitMemOperand - Return true if the specified instruction has
/// a 32-bit memory operand. Op specifies the operand # of the memoperand.
static bool Is32BitMemOperand(const MachineInstr &MI, unsigned Op) {
const MachineOperand &BaseReg = MI.getOperand(Op+X86::AddrBaseReg);
const MachineOperand &IndexReg = MI.getOperand(Op+X86::AddrIndexReg);
if ((BaseReg.getReg() != 0 &&
X86MCRegisterClasses[X86::GR32RegClassID].contains(BaseReg.getReg())) ||
(IndexReg.getReg() != 0 &&
X86MCRegisterClasses[X86::GR32RegClassID].contains(IndexReg.getReg())))
return true;
return false;
}
/// Is64BitMemOperand - Return true if the specified instruction has
/// a 64-bit memory operand. Op specifies the operand # of the memoperand.
#ifndef NDEBUG
static bool Is64BitMemOperand(const MachineInstr &MI, unsigned Op) {
const MachineOperand &BaseReg = MI.getOperand(Op+X86::AddrBaseReg);
const MachineOperand &IndexReg = MI.getOperand(Op+X86::AddrIndexReg);
if ((BaseReg.getReg() != 0 &&
X86MCRegisterClasses[X86::GR64RegClassID].contains(BaseReg.getReg())) ||
(IndexReg.getReg() != 0 &&
X86MCRegisterClasses[X86::GR64RegClassID].contains(IndexReg.getReg())))
return true;
return false;
}
#endif
template<class CodeEmitter>
void Emitter<CodeEmitter>::emitOpcodePrefix(uint64_t TSFlags,
int MemOperand,
const MachineInstr &MI,
const MCInstrDesc *Desc) const {
// Emit the lock opcode prefix as needed.
if (Desc->TSFlags & X86II::LOCK)
MCE.emitByte(0xF0);
// Emit segment override opcode prefix as needed.
emitSegmentOverridePrefix(TSFlags, MemOperand, MI);
// Emit the repeat opcode prefix as needed.
if ((Desc->TSFlags & X86II::Op0Mask) == X86II::REP)
MCE.emitByte(0xF3);
// Emit the address size opcode prefix as needed.
bool need_address_override;
if (TSFlags & X86II::AdSize) {
need_address_override = true;
} else if (MemOperand == -1) {
need_address_override = false;
} else if (Is64BitMode) {
assert(!Is16BitMemOperand(MI, MemOperand));
need_address_override = Is32BitMemOperand(MI, MemOperand);
} else {
assert(!Is64BitMemOperand(MI, MemOperand));
need_address_override = Is16BitMemOperand(MI, MemOperand);
}
if (need_address_override)
MCE.emitByte(0x67);
// Emit the operand size opcode prefix as needed.
if (TSFlags & X86II::OpSize)
MCE.emitByte(0x66);
bool Need0FPrefix = false;
switch (Desc->TSFlags & X86II::Op0Mask) {
case X86II::TB: // Two-byte opcode prefix
case X86II::T8: // 0F 38
case X86II::TA: // 0F 3A
case X86II::A6: // 0F A6
case X86II::A7: // 0F A7
Need0FPrefix = true;
break;
case X86II::REP: break; // already handled.
case X86II::T8XS: // F3 0F 38
case X86II::XS: // F3 0F
MCE.emitByte(0xF3);
Need0FPrefix = true;
break;
case X86II::T8XD: // F2 0F 38
case X86II::TAXD: // F2 0F 3A
case X86II::XD: // F2 0F
MCE.emitByte(0xF2);
Need0FPrefix = true;
break;
case X86II::D8: case X86II::D9: case X86II::DA: case X86II::DB:
case X86II::DC: case X86II::DD: case X86II::DE: case X86II::DF:
MCE.emitByte(0xD8+
(((Desc->TSFlags & X86II::Op0Mask)-X86II::D8)
>> X86II::Op0Shift));
break; // Two-byte opcode prefix
default: llvm_unreachable("Invalid prefix!");
case 0: break; // No prefix!
}
// Handle REX prefix.
if (Is64BitMode) {
if (unsigned REX = determineREX(MI))
MCE.emitByte(0x40 | REX);
}
// 0x0F escape code must be emitted just before the opcode.
if (Need0FPrefix)
MCE.emitByte(0x0F);
switch (Desc->TSFlags & X86II::Op0Mask) {
case X86II::T8XD: // F2 0F 38
case X86II::T8XS: // F3 0F 38
case X86II::T8: // 0F 38
MCE.emitByte(0x38);
break;
case X86II::TAXD: // F2 0F 38
case X86II::TA: // 0F 3A
MCE.emitByte(0x3A);
break;
case X86II::A6: // 0F A6
MCE.emitByte(0xA6);
break;
case X86II::A7: // 0F A7
MCE.emitByte(0xA7);
break;
}
}
// On regular x86, both XMM0-XMM7 and XMM8-XMM15 are encoded in the range
// 0-7 and the difference between the 2 groups is given by the REX prefix.
// In the VEX prefix, registers are seen sequencially from 0-15 and encoded
// in 1's complement form, example:
//
// ModRM field => XMM9 => 1
// VEX.VVVV => XMM9 => ~9
//
// See table 4-35 of Intel AVX Programming Reference for details.
template<class CodeEmitter>
unsigned char
Emitter<CodeEmitter>::getVEXRegisterEncoding(const MachineInstr &MI,
unsigned OpNum) const {
unsigned SrcReg = MI.getOperand(OpNum).getReg();
unsigned SrcRegNum = getX86RegNum(MI.getOperand(OpNum).getReg());
if (X86II::isX86_64ExtendedReg(SrcReg))
SrcRegNum |= 8;
// The registers represented through VEX_VVVV should
// be encoded in 1's complement form.
return (~SrcRegNum) & 0xf;
}
/// EmitSegmentOverridePrefix - Emit segment override opcode prefix as needed
template<class CodeEmitter>
void Emitter<CodeEmitter>::emitSegmentOverridePrefix(uint64_t TSFlags,
int MemOperand,
const MachineInstr &MI) const {
switch (TSFlags & X86II::SegOvrMask) {
default: llvm_unreachable("Invalid segment!");
case 0:
// No segment override, check for explicit one on memory operand.
if (MemOperand != -1) { // If the instruction has a memory operand.
switch (MI.getOperand(MemOperand+X86::AddrSegmentReg).getReg()) {
default: llvm_unreachable("Unknown segment register!");
case 0: break;
case X86::CS: MCE.emitByte(0x2E); break;
case X86::SS: MCE.emitByte(0x36); break;
case X86::DS: MCE.emitByte(0x3E); break;
case X86::ES: MCE.emitByte(0x26); break;
case X86::FS: MCE.emitByte(0x64); break;
case X86::GS: MCE.emitByte(0x65); break;
}
}
break;
case X86II::FS:
MCE.emitByte(0x64);
break;
case X86II::GS:
MCE.emitByte(0x65);
break;
}
}
template<class CodeEmitter>
void Emitter<CodeEmitter>::emitVEXOpcodePrefix(uint64_t TSFlags,
int MemOperand,
const MachineInstr &MI,
const MCInstrDesc *Desc) const {
bool HasVEX_4V = (TSFlags >> X86II::VEXShift) & X86II::VEX_4V;
bool HasVEX_4VOp3 = (TSFlags >> X86II::VEXShift) & X86II::VEX_4VOp3;
// VEX_R: opcode externsion equivalent to REX.R in
// 1's complement (inverted) form
//
// 1: Same as REX_R=0 (must be 1 in 32-bit mode)
// 0: Same as REX_R=1 (64 bit mode only)
//
unsigned char VEX_R = 0x1;
// VEX_X: equivalent to REX.X, only used when a
// register is used for index in SIB Byte.
//
// 1: Same as REX.X=0 (must be 1 in 32-bit mode)
// 0: Same as REX.X=1 (64-bit mode only)
unsigned char VEX_X = 0x1;
// VEX_B:
//
// 1: Same as REX_B=0 (ignored in 32-bit mode)
// 0: Same as REX_B=1 (64 bit mode only)
//
unsigned char VEX_B = 0x1;
// VEX_W: opcode specific (use like REX.W, or used for
// opcode extension, or ignored, depending on the opcode byte)
unsigned char VEX_W = 0;
// XOP: Use XOP prefix byte 0x8f instead of VEX.
unsigned char XOP = 0;
// VEX_5M (VEX m-mmmmm field):
//
// 0b00000: Reserved for future use
// 0b00001: implied 0F leading opcode
// 0b00010: implied 0F 38 leading opcode bytes
// 0b00011: implied 0F 3A leading opcode bytes
// 0b00100-0b11111: Reserved for future use
// 0b01000: XOP map select - 08h instructions with imm byte
// 0b10001: XOP map select - 09h instructions with no imm byte
unsigned char VEX_5M = 0x1;
// VEX_4V (VEX vvvv field): a register specifier
// (in 1's complement form) or 1111 if unused.
unsigned char VEX_4V = 0xf;
// VEX_L (Vector Length):
//
// 0: scalar or 128-bit vector
// 1: 256-bit vector
//
unsigned char VEX_L = 0;
// VEX_PP: opcode extension providing equivalent
// functionality of a SIMD prefix
//
// 0b00: None
// 0b01: 66
// 0b10: F3
// 0b11: F2
//
unsigned char VEX_PP = 0;
// Encode the operand size opcode prefix as needed.
if (TSFlags & X86II::OpSize)
VEX_PP = 0x01;
if ((TSFlags >> X86II::VEXShift) & X86II::VEX_W)
VEX_W = 1;
if ((TSFlags >> X86II::VEXShift) & X86II::XOP)
XOP = 1;
if ((TSFlags >> X86II::VEXShift) & X86II::VEX_L)
VEX_L = 1;
switch (TSFlags & X86II::Op0Mask) {
default: llvm_unreachable("Invalid prefix!");
case X86II::T8: // 0F 38
VEX_5M = 0x2;
break;
case X86II::TA: // 0F 3A
VEX_5M = 0x3;
break;
case X86II::T8XS: // F3 0F 38
VEX_PP = 0x2;
VEX_5M = 0x2;
break;
case X86II::T8XD: // F2 0F 38
VEX_PP = 0x3;
VEX_5M = 0x2;
break;
case X86II::TAXD: // F2 0F 3A
VEX_PP = 0x3;
VEX_5M = 0x3;
break;
case X86II::XS: // F3 0F
VEX_PP = 0x2;
break;
case X86II::XD: // F2 0F
VEX_PP = 0x3;
break;
case X86II::XOP8:
VEX_5M = 0x8;
break;
case X86II::XOP9:
VEX_5M = 0x9;
break;
case X86II::A6: // Bypass: Not used by VEX
case X86II::A7: // Bypass: Not used by VEX
case X86II::TB: // Bypass: Not used by VEX
case 0:
break; // No prefix!
}
// Classify VEX_B, VEX_4V, VEX_R, VEX_X
unsigned NumOps = Desc->getNumOperands();
unsigned CurOp = 0;
if (NumOps > 1 && Desc->getOperandConstraint(1, MCOI::TIED_TO) == 0)
++CurOp;
else if (NumOps > 3 && Desc->getOperandConstraint(2, MCOI::TIED_TO) == 0) {
assert(Desc->getOperandConstraint(NumOps - 1, MCOI::TIED_TO) == 1);
// Special case for GATHER with 2 TIED_TO operands
// Skip the first 2 operands: dst, mask_wb
CurOp += 2;
}
switch (TSFlags & X86II::FormMask) {
case X86II::MRMInitReg:
// Duplicate register.
if (X86II::isX86_64ExtendedReg(MI.getOperand(CurOp).getReg()))
VEX_R = 0x0;
if (HasVEX_4V)
VEX_4V = getVEXRegisterEncoding(MI, CurOp);
if (X86II::isX86_64ExtendedReg(MI.getOperand(CurOp).getReg()))
VEX_B = 0x0;
if (HasVEX_4VOp3)
VEX_4V = getVEXRegisterEncoding(MI, CurOp);
break;
case X86II::MRMDestMem: {
// MRMDestMem instructions forms:
// MemAddr, src1(ModR/M)
// MemAddr, src1(VEX_4V), src2(ModR/M)
// MemAddr, src1(ModR/M), imm8
//
if (X86II::isX86_64ExtendedReg(MI.getOperand(X86::AddrBaseReg).getReg()))
VEX_B = 0x0;
if (X86II::isX86_64ExtendedReg(MI.getOperand(X86::AddrIndexReg).getReg()))
VEX_X = 0x0;
CurOp = X86::AddrNumOperands;
if (HasVEX_4V)
VEX_4V = getVEXRegisterEncoding(MI, CurOp++);
const MachineOperand &MO = MI.getOperand(CurOp);
if (MO.isReg() && X86II::isX86_64ExtendedReg(MO.getReg()))
VEX_R = 0x0;
break;
}
case X86II::MRMSrcMem:
// MRMSrcMem instructions forms:
// src1(ModR/M), MemAddr
// src1(ModR/M), src2(VEX_4V), MemAddr
// src1(ModR/M), MemAddr, imm8
// src1(ModR/M), MemAddr, src2(VEX_I8IMM)
//
// FMA4:
// dst(ModR/M.reg), src1(VEX_4V), src2(ModR/M), src3(VEX_I8IMM)
// dst(ModR/M.reg), src1(VEX_4V), src2(VEX_I8IMM), src3(ModR/M),
if (X86II::isX86_64ExtendedReg(MI.getOperand(0).getReg()))
VEX_R = 0x0;
if (HasVEX_4V)
VEX_4V = getVEXRegisterEncoding(MI, 1);
if (X86II::isX86_64ExtendedReg(
MI.getOperand(MemOperand+X86::AddrBaseReg).getReg()))
VEX_B = 0x0;
if (X86II::isX86_64ExtendedReg(
MI.getOperand(MemOperand+X86::AddrIndexReg).getReg()))
VEX_X = 0x0;
if (HasVEX_4VOp3)
VEX_4V = getVEXRegisterEncoding(MI, X86::AddrNumOperands+1);
break;
case X86II::MRM0m: case X86II::MRM1m:
case X86II::MRM2m: case X86II::MRM3m:
case X86II::MRM4m: case X86II::MRM5m:
case X86II::MRM6m: case X86II::MRM7m: {
// MRM[0-9]m instructions forms:
// MemAddr
// src1(VEX_4V), MemAddr
if (HasVEX_4V)
VEX_4V = getVEXRegisterEncoding(MI, 0);
if (X86II::isX86_64ExtendedReg(
MI.getOperand(MemOperand+X86::AddrBaseReg).getReg()))
VEX_B = 0x0;
if (X86II::isX86_64ExtendedReg(
MI.getOperand(MemOperand+X86::AddrIndexReg).getReg()))
VEX_X = 0x0;
break;
}
case X86II::MRMSrcReg:
// MRMSrcReg instructions forms:
// dst(ModR/M), src1(VEX_4V), src2(ModR/M), src3(VEX_I8IMM)
// dst(ModR/M), src1(ModR/M)
// dst(ModR/M), src1(ModR/M), imm8
//
if (X86II::isX86_64ExtendedReg(MI.getOperand(CurOp).getReg()))
VEX_R = 0x0;
CurOp++;
if (HasVEX_4V)
VEX_4V = getVEXRegisterEncoding(MI, CurOp++);
if (X86II::isX86_64ExtendedReg(MI.getOperand(CurOp).getReg()))
VEX_B = 0x0;
CurOp++;
if (HasVEX_4VOp3)
VEX_4V = getVEXRegisterEncoding(MI, CurOp);
break;
case X86II::MRMDestReg:
// MRMDestReg instructions forms:
// dst(ModR/M), src(ModR/M)
// dst(ModR/M), src(ModR/M), imm8
if (X86II::isX86_64ExtendedReg(MI.getOperand(0).getReg()))
VEX_B = 0x0;
if (X86II::isX86_64ExtendedReg(MI.getOperand(1).getReg()))
VEX_R = 0x0;
break;
case X86II::MRM0r: case X86II::MRM1r:
case X86II::MRM2r: case X86II::MRM3r:
case X86II::MRM4r: case X86II::MRM5r:
case X86II::MRM6r: case X86II::MRM7r:
// MRM0r-MRM7r instructions forms:
// dst(VEX_4V), src(ModR/M), imm8
VEX_4V = getVEXRegisterEncoding(MI, 0);
if (X86II::isX86_64ExtendedReg(MI.getOperand(1).getReg()))
VEX_B = 0x0;
break;
default: // RawFrm
break;
}
// Emit segment override opcode prefix as needed.
emitSegmentOverridePrefix(TSFlags, MemOperand, MI);
// VEX opcode prefix can have 2 or 3 bytes
//
// 3 bytes:
// +-----+ +--------------+ +-------------------+
// | C4h | | RXB | m-mmmm | | W | vvvv | L | pp |
// +-----+ +--------------+ +-------------------+
// 2 bytes:
// +-----+ +-------------------+
// | C5h | | R | vvvv | L | pp |
// +-----+ +-------------------+
//
unsigned char LastByte = VEX_PP | (VEX_L << 2) | (VEX_4V << 3);
if (VEX_B && VEX_X && !VEX_W && !XOP && (VEX_5M == 1)) { // 2 byte VEX prefix
MCE.emitByte(0xC5);
MCE.emitByte(LastByte | (VEX_R << 7));
return;
}
// 3 byte VEX prefix
MCE.emitByte(XOP ? 0x8F : 0xC4);
MCE.emitByte(VEX_R << 7 | VEX_X << 6 | VEX_B << 5 | VEX_5M);
MCE.emitByte(LastByte | (VEX_W << 7));
}
template<class CodeEmitter>
void Emitter<CodeEmitter>::emitInstruction(MachineInstr &MI,
const MCInstrDesc *Desc) {
DEBUG(dbgs() << MI);
// If this is a pseudo instruction, lower it.
switch (Desc->getOpcode()) {
case X86::ADD16rr_DB: Desc = UpdateOp(MI, II, X86::OR16rr); break;
case X86::ADD32rr_DB: Desc = UpdateOp(MI, II, X86::OR32rr); break;
case X86::ADD64rr_DB: Desc = UpdateOp(MI, II, X86::OR64rr); break;
case X86::ADD16ri_DB: Desc = UpdateOp(MI, II, X86::OR16ri); break;
case X86::ADD32ri_DB: Desc = UpdateOp(MI, II, X86::OR32ri); break;
case X86::ADD64ri32_DB: Desc = UpdateOp(MI, II, X86::OR64ri32); break;
case X86::ADD16ri8_DB: Desc = UpdateOp(MI, II, X86::OR16ri8); break;
case X86::ADD32ri8_DB: Desc = UpdateOp(MI, II, X86::OR32ri8); break;
case X86::ADD64ri8_DB: Desc = UpdateOp(MI, II, X86::OR64ri8); break;
case X86::ACQUIRE_MOV8rm: Desc = UpdateOp(MI, II, X86::MOV8rm); break;
case X86::ACQUIRE_MOV16rm: Desc = UpdateOp(MI, II, X86::MOV16rm); break;
case X86::ACQUIRE_MOV32rm: Desc = UpdateOp(MI, II, X86::MOV32rm); break;
case X86::ACQUIRE_MOV64rm: Desc = UpdateOp(MI, II, X86::MOV64rm); break;
case X86::RELEASE_MOV8mr: Desc = UpdateOp(MI, II, X86::MOV8mr); break;
case X86::RELEASE_MOV16mr: Desc = UpdateOp(MI, II, X86::MOV16mr); break;
case X86::RELEASE_MOV32mr: Desc = UpdateOp(MI, II, X86::MOV32mr); break;
case X86::RELEASE_MOV64mr: Desc = UpdateOp(MI, II, X86::MOV64mr); break;
}
MCE.processDebugLoc(MI.getDebugLoc(), true);
unsigned Opcode = Desc->Opcode;
// If this is a two-address instruction, skip one of the register operands.
unsigned NumOps = Desc->getNumOperands();
unsigned CurOp = 0;
if (NumOps > 1 && Desc->getOperandConstraint(1, MCOI::TIED_TO) == 0)
++CurOp;
else if (NumOps > 3 && Desc->getOperandConstraint(2, MCOI::TIED_TO) == 0) {
assert(Desc->getOperandConstraint(NumOps - 1, MCOI::TIED_TO) == 1);
// Special case for GATHER with 2 TIED_TO operands
// Skip the first 2 operands: dst, mask_wb
CurOp += 2;
}
uint64_t TSFlags = Desc->TSFlags;
// Is this instruction encoded using the AVX VEX prefix?
bool HasVEXPrefix = (TSFlags >> X86II::VEXShift) & X86II::VEX;
// It uses the VEX.VVVV field?
bool HasVEX_4V = (TSFlags >> X86II::VEXShift) & X86II::VEX_4V;
bool HasVEX_4VOp3 = (TSFlags >> X86II::VEXShift) & X86II::VEX_4VOp3;
bool HasMemOp4 = (TSFlags >> X86II::VEXShift) & X86II::MemOp4;
const unsigned MemOp4_I8IMMOperand = 2;
// Determine where the memory operand starts, if present.
int MemoryOperand = X86II::getMemoryOperandNo(TSFlags, Opcode);
if (MemoryOperand != -1) MemoryOperand += CurOp;
if (!HasVEXPrefix)
emitOpcodePrefix(TSFlags, MemoryOperand, MI, Desc);
else
emitVEXOpcodePrefix(TSFlags, MemoryOperand, MI, Desc);
unsigned char BaseOpcode = X86II::getBaseOpcodeFor(Desc->TSFlags);
switch (TSFlags & X86II::FormMask) {
default:
llvm_unreachable("Unknown FormMask value in X86 MachineCodeEmitter!");
case X86II::Pseudo:
// Remember the current PC offset, this is the PIC relocation
// base address.
switch (Opcode) {
default:
llvm_unreachable("pseudo instructions should be removed before code"
" emission");
// Do nothing for Int_MemBarrier - it's just a comment. Add a debug
// to make it slightly easier to see.
case X86::Int_MemBarrier:
DEBUG(dbgs() << "#MEMBARRIER\n");
break;
case TargetOpcode::INLINEASM:
// We allow inline assembler nodes with empty bodies - they can
// implicitly define registers, which is ok for JIT.
if (MI.getOperand(0).getSymbolName()[0])
report_fatal_error("JIT does not support inline asm!");
break;
case TargetOpcode::PROLOG_LABEL:
case TargetOpcode::GC_LABEL:
case TargetOpcode::EH_LABEL:
MCE.emitLabel(MI.getOperand(0).getMCSymbol());
break;
case TargetOpcode::IMPLICIT_DEF:
case TargetOpcode::KILL:
break;
case X86::MOVPC32r: {
// This emits the "call" portion of this pseudo instruction.
MCE.emitByte(BaseOpcode);
emitConstant(0, X86II::getSizeOfImm(Desc->TSFlags));
// Remember PIC base.
PICBaseOffset = (intptr_t) MCE.getCurrentPCOffset();
X86JITInfo *JTI = TM.getJITInfo();
JTI->setPICBase(MCE.getCurrentPCValue());
break;
}
}
CurOp = NumOps;
break;
case X86II::RawFrm: {
MCE.emitByte(BaseOpcode);
if (CurOp == NumOps)
break;
const MachineOperand &MO = MI.getOperand(CurOp++);
DEBUG(dbgs() << "RawFrm CurOp " << CurOp << "\n");
DEBUG(dbgs() << "isMBB " << MO.isMBB() << "\n");
DEBUG(dbgs() << "isGlobal " << MO.isGlobal() << "\n");
DEBUG(dbgs() << "isSymbol " << MO.isSymbol() << "\n");
DEBUG(dbgs() << "isImm " << MO.isImm() << "\n");
if (MO.isMBB()) {
emitPCRelativeBlockAddress(MO.getMBB());
break;
}
if (MO.isGlobal()) {
emitGlobalAddress(MO.getGlobal(), X86::reloc_pcrel_word,
MO.getOffset(), 0);
break;
}
if (MO.isSymbol()) {
emitExternalSymbolAddress(MO.getSymbolName(), X86::reloc_pcrel_word);
break;
}
// FIXME: Only used by hackish MCCodeEmitter, remove when dead.
if (MO.isJTI()) {
emitJumpTableAddress(MO.getIndex(), X86::reloc_pcrel_word);
break;
}
assert(MO.isImm() && "Unknown RawFrm operand!");
if (Opcode == X86::CALLpcrel32 || Opcode == X86::CALL64pcrel32) {
// Fix up immediate operand for pc relative calls.
intptr_t Imm = (intptr_t)MO.getImm();
Imm = Imm - MCE.getCurrentPCValue() - 4;
emitConstant(Imm, X86II::getSizeOfImm(Desc->TSFlags));
} else
emitConstant(MO.getImm(), X86II::getSizeOfImm(Desc->TSFlags));
break;
}
case X86II::AddRegFrm: {
MCE.emitByte(BaseOpcode +
getX86RegNum(MI.getOperand(CurOp++).getReg()));
if (CurOp == NumOps)
break;
const MachineOperand &MO1 = MI.getOperand(CurOp++);
unsigned Size = X86II::getSizeOfImm(Desc->TSFlags);
if (MO1.isImm()) {
emitConstant(MO1.getImm(), Size);
break;
}
unsigned rt = Is64BitMode ? X86::reloc_pcrel_word
: (IsPIC ? X86::reloc_picrel_word : X86::reloc_absolute_word);
if (Opcode == X86::MOV64ri64i32)
rt = X86::reloc_absolute_word; // FIXME: add X86II flag?
// This should not occur on Darwin for relocatable objects.
if (Opcode == X86::MOV64ri)
rt = X86::reloc_absolute_dword; // FIXME: add X86II flag?
if (MO1.isGlobal()) {
bool Indirect = gvNeedsNonLazyPtr(MO1, TM);
emitGlobalAddress(MO1.getGlobal(), rt, MO1.getOffset(), 0,
Indirect);
} else if (MO1.isSymbol())
emitExternalSymbolAddress(MO1.getSymbolName(), rt);
else if (MO1.isCPI())
emitConstPoolAddress(MO1.getIndex(), rt);
else if (MO1.isJTI())
emitJumpTableAddress(MO1.getIndex(), rt);
break;
}
case X86II::MRMDestReg: {
MCE.emitByte(BaseOpcode);
emitRegModRMByte(MI.getOperand(CurOp).getReg(),
getX86RegNum(MI.getOperand(CurOp+1).getReg()));
CurOp += 2;
break;
}
case X86II::MRMDestMem: {
MCE.emitByte(BaseOpcode);
unsigned SrcRegNum = CurOp + X86::AddrNumOperands;
if (HasVEX_4V) // Skip 1st src (which is encoded in VEX_VVVV)
SrcRegNum++;
emitMemModRMByte(MI, CurOp,
getX86RegNum(MI.getOperand(SrcRegNum).getReg()));
CurOp = SrcRegNum + 1;
break;
}
case X86II::MRMSrcReg: {
MCE.emitByte(BaseOpcode);
unsigned SrcRegNum = CurOp+1;
if (HasVEX_4V) // Skip 1st src (which is encoded in VEX_VVVV)
++SrcRegNum;
if (HasMemOp4) // Skip 2nd src (which is encoded in I8IMM)
++SrcRegNum;
emitRegModRMByte(MI.getOperand(SrcRegNum).getReg(),
getX86RegNum(MI.getOperand(CurOp).getReg()));
// 2 operands skipped with HasMemOp4, compensate accordingly
CurOp = HasMemOp4 ? SrcRegNum : SrcRegNum + 1;
if (HasVEX_4VOp3)
++CurOp;
break;
}
case X86II::MRMSrcMem: {
int AddrOperands = X86::AddrNumOperands;
unsigned FirstMemOp = CurOp+1;
if (HasVEX_4V) {
++AddrOperands;
++FirstMemOp; // Skip the register source (which is encoded in VEX_VVVV).
}
if (HasMemOp4) // Skip second register source (encoded in I8IMM)
++FirstMemOp;
MCE.emitByte(BaseOpcode);
intptr_t PCAdj = (CurOp + AddrOperands + 1 != NumOps) ?
X86II::getSizeOfImm(Desc->TSFlags) : 0;
emitMemModRMByte(MI, FirstMemOp,
getX86RegNum(MI.getOperand(CurOp).getReg()),PCAdj);
CurOp += AddrOperands + 1;
if (HasVEX_4VOp3)
++CurOp;
break;
}
case X86II::MRM0r: case X86II::MRM1r:
case X86II::MRM2r: case X86II::MRM3r:
case X86II::MRM4r: case X86II::MRM5r:
case X86II::MRM6r: case X86II::MRM7r: {
if (HasVEX_4V) // Skip the register dst (which is encoded in VEX_VVVV).
++CurOp;
MCE.emitByte(BaseOpcode);
emitRegModRMByte(MI.getOperand(CurOp++).getReg(),
(Desc->TSFlags & X86II::FormMask)-X86II::MRM0r);
if (CurOp == NumOps)
break;
const MachineOperand &MO1 = MI.getOperand(CurOp++);
unsigned Size = X86II::getSizeOfImm(Desc->TSFlags);
if (MO1.isImm()) {
emitConstant(MO1.getImm(), Size);
break;
}
unsigned rt = Is64BitMode ? X86::reloc_pcrel_word
: (IsPIC ? X86::reloc_picrel_word : X86::reloc_absolute_word);
if (Opcode == X86::MOV64ri32)
rt = X86::reloc_absolute_word_sext; // FIXME: add X86II flag?
if (MO1.isGlobal()) {
bool Indirect = gvNeedsNonLazyPtr(MO1, TM);
emitGlobalAddress(MO1.getGlobal(), rt, MO1.getOffset(), 0,
Indirect);
} else if (MO1.isSymbol())
emitExternalSymbolAddress(MO1.getSymbolName(), rt);
else if (MO1.isCPI())
emitConstPoolAddress(MO1.getIndex(), rt);
else if (MO1.isJTI())
emitJumpTableAddress(MO1.getIndex(), rt);
break;
}
case X86II::MRM0m: case X86II::MRM1m:
case X86II::MRM2m: case X86II::MRM3m:
case X86II::MRM4m: case X86II::MRM5m:
case X86II::MRM6m: case X86II::MRM7m: {
if (HasVEX_4V) // Skip the register dst (which is encoded in VEX_VVVV).
++CurOp;
intptr_t PCAdj = (CurOp + X86::AddrNumOperands != NumOps) ?
(MI.getOperand(CurOp+X86::AddrNumOperands).isImm() ?
X86II::getSizeOfImm(Desc->TSFlags) : 4) : 0;
MCE.emitByte(BaseOpcode);
emitMemModRMByte(MI, CurOp, (Desc->TSFlags & X86II::FormMask)-X86II::MRM0m,
PCAdj);
CurOp += X86::AddrNumOperands;
if (CurOp == NumOps)
break;
const MachineOperand &MO = MI.getOperand(CurOp++);
unsigned Size = X86II::getSizeOfImm(Desc->TSFlags);
if (MO.isImm()) {
emitConstant(MO.getImm(), Size);
break;
}
unsigned rt = Is64BitMode ? X86::reloc_pcrel_word
: (IsPIC ? X86::reloc_picrel_word : X86::reloc_absolute_word);
if (Opcode == X86::MOV64mi32)
rt = X86::reloc_absolute_word_sext; // FIXME: add X86II flag?
if (MO.isGlobal()) {
bool Indirect = gvNeedsNonLazyPtr(MO, TM);
emitGlobalAddress(MO.getGlobal(), rt, MO.getOffset(), 0,
Indirect);
} else if (MO.isSymbol())
emitExternalSymbolAddress(MO.getSymbolName(), rt);
else if (MO.isCPI())
emitConstPoolAddress(MO.getIndex(), rt);
else if (MO.isJTI())
emitJumpTableAddress(MO.getIndex(), rt);
break;
}
case X86II::MRMInitReg:
MCE.emitByte(BaseOpcode);
// Duplicate register, used by things like MOV8r0 (aka xor reg,reg).
emitRegModRMByte(MI.getOperand(CurOp).getReg(),
getX86RegNum(MI.getOperand(CurOp).getReg()));
++CurOp;
break;
case X86II::MRM_C1:
MCE.emitByte(BaseOpcode);
MCE.emitByte(0xC1);
break;
case X86II::MRM_C8:
MCE.emitByte(BaseOpcode);
MCE.emitByte(0xC8);
break;
case X86II::MRM_C9:
MCE.emitByte(BaseOpcode);
MCE.emitByte(0xC9);
break;
case X86II::MRM_E8:
MCE.emitByte(BaseOpcode);
MCE.emitByte(0xE8);
break;
case X86II::MRM_F0:
MCE.emitByte(BaseOpcode);
MCE.emitByte(0xF0);
break;
}
while (CurOp != NumOps && NumOps - CurOp <= 2) {
// The last source register of a 4 operand instruction in AVX is encoded
// in bits[7:4] of a immediate byte.
if ((TSFlags >> X86II::VEXShift) & X86II::VEX_I8IMM) {
const MachineOperand &MO = MI.getOperand(HasMemOp4 ? MemOp4_I8IMMOperand
: CurOp);
++CurOp;
unsigned RegNum = getX86RegNum(MO.getReg()) << 4;
if (X86II::isX86_64ExtendedReg(MO.getReg()))
RegNum |= 1 << 7;
// If there is an additional 5th operand it must be an immediate, which
// is encoded in bits[3:0]
if (CurOp != NumOps) {
const MachineOperand &MIMM = MI.getOperand(CurOp++);
if (MIMM.isImm()) {
unsigned Val = MIMM.getImm();
assert(Val < 16 && "Immediate operand value out of range");
RegNum |= Val;
}
}
emitConstant(RegNum, 1);
} else {
emitConstant(MI.getOperand(CurOp++).getImm(),
X86II::getSizeOfImm(Desc->TSFlags));
}
}
if (!MI.isVariadic() && CurOp != NumOps) {
#ifndef NDEBUG
dbgs() << "Cannot encode all operands of: " << MI << "\n";
#endif
llvm_unreachable(0);
}
MCE.processDebugLoc(MI.getDebugLoc(), false);
}
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