1 //===-- X86/X86MCCodeEmitter.cpp - Convert X86 code to machine code -------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements the X86MCCodeEmitter class.
12 //===----------------------------------------------------------------------===//
14 #define DEBUG_TYPE "x86-emitter"
16 #include "X86InstrInfo.h"
17 #include "X86FixupKinds.h"
18 #include "llvm/MC/MCCodeEmitter.h"
19 #include "llvm/MC/MCExpr.h"
20 #include "llvm/MC/MCInst.h"
21 #include "llvm/Support/raw_ostream.h"
25 class X86MCCodeEmitter : public MCCodeEmitter {
26 X86MCCodeEmitter(const X86MCCodeEmitter &); // DO NOT IMPLEMENT
27 void operator=(const X86MCCodeEmitter &); // DO NOT IMPLEMENT
28 const TargetMachine &TM;
29 const TargetInstrInfo &TII;
33 X86MCCodeEmitter(TargetMachine &tm, MCContext &ctx, bool is64Bit)
34 : TM(tm), TII(*TM.getInstrInfo()), Ctx(ctx) {
35 Is64BitMode = is64Bit;
38 ~X86MCCodeEmitter() {}
40 unsigned getNumFixupKinds() const {
44 const MCFixupKindInfo &getFixupKindInfo(MCFixupKind Kind) const {
45 const static MCFixupKindInfo Infos[] = {
46 { "reloc_pcrel_4byte", 0, 4 * 8 },
47 { "reloc_pcrel_1byte", 0, 1 * 8 },
48 { "reloc_riprel_4byte", 0, 4 * 8 },
49 { "reloc_riprel_4byte_movq_load", 0, 4 * 8 }
52 if (Kind < FirstTargetFixupKind)
53 return MCCodeEmitter::getFixupKindInfo(Kind);
55 assert(unsigned(Kind - FirstTargetFixupKind) < getNumFixupKinds() &&
57 return Infos[Kind - FirstTargetFixupKind];
60 static unsigned GetX86RegNum(const MCOperand &MO) {
61 return X86RegisterInfo::getX86RegNum(MO.getReg());
64 void EmitByte(unsigned char C, unsigned &CurByte, raw_ostream &OS) const {
69 void EmitConstant(uint64_t Val, unsigned Size, unsigned &CurByte,
70 raw_ostream &OS) const {
71 // Output the constant in little endian byte order.
72 for (unsigned i = 0; i != Size; ++i) {
73 EmitByte(Val & 255, CurByte, OS);
78 void EmitImmediate(const MCOperand &Disp,
79 unsigned ImmSize, MCFixupKind FixupKind,
80 unsigned &CurByte, raw_ostream &OS,
81 SmallVectorImpl<MCFixup> &Fixups,
82 int ImmOffset = 0) const;
84 inline static unsigned char ModRMByte(unsigned Mod, unsigned RegOpcode,
86 assert(Mod < 4 && RegOpcode < 8 && RM < 8 && "ModRM Fields out of range!");
87 return RM | (RegOpcode << 3) | (Mod << 6);
90 void EmitRegModRMByte(const MCOperand &ModRMReg, unsigned RegOpcodeFld,
91 unsigned &CurByte, raw_ostream &OS) const {
92 EmitByte(ModRMByte(3, RegOpcodeFld, GetX86RegNum(ModRMReg)), CurByte, OS);
95 void EmitSIBByte(unsigned SS, unsigned Index, unsigned Base,
96 unsigned &CurByte, raw_ostream &OS) const {
97 // SIB byte is in the same format as the ModRMByte.
98 EmitByte(ModRMByte(SS, Index, Base), CurByte, OS);
102 void EmitMemModRMByte(const MCInst &MI, unsigned Op,
103 unsigned RegOpcodeField,
104 unsigned TSFlags, unsigned &CurByte, raw_ostream &OS,
105 SmallVectorImpl<MCFixup> &Fixups) const;
107 void EncodeInstruction(const MCInst &MI, raw_ostream &OS,
108 SmallVectorImpl<MCFixup> &Fixups) const;
112 } // end anonymous namespace
115 MCCodeEmitter *llvm::createX86_32MCCodeEmitter(const Target &,
118 return new X86MCCodeEmitter(TM, Ctx, false);
121 MCCodeEmitter *llvm::createX86_64MCCodeEmitter(const Target &,
124 return new X86MCCodeEmitter(TM, Ctx, true);
128 /// isDisp8 - Return true if this signed displacement fits in a 8-bit
129 /// sign-extended field.
130 static bool isDisp8(int Value) {
131 return Value == (signed char)Value;
134 /// getImmFixupKind - Return the appropriate fixup kind to use for an immediate
135 /// in an instruction with the specified TSFlags.
136 static MCFixupKind getImmFixupKind(unsigned TSFlags) {
137 unsigned Size = X86II::getSizeOfImm(TSFlags);
138 bool isPCRel = X86II::isImmPCRel(TSFlags);
141 default: assert(0 && "Unknown immediate size");
142 case 1: return isPCRel ? MCFixupKind(X86::reloc_pcrel_1byte) : FK_Data_1;
143 case 4: return isPCRel ? MCFixupKind(X86::reloc_pcrel_4byte) : FK_Data_4;
144 case 2: assert(!isPCRel); return FK_Data_2;
145 case 8: assert(!isPCRel); return FK_Data_8;
150 void X86MCCodeEmitter::
151 EmitImmediate(const MCOperand &DispOp, unsigned Size, MCFixupKind FixupKind,
152 unsigned &CurByte, raw_ostream &OS,
153 SmallVectorImpl<MCFixup> &Fixups, int ImmOffset) const {
154 // If this is a simple integer displacement that doesn't require a relocation,
156 if (DispOp.isImm()) {
157 // FIXME: is this right for pc-rel encoding?? Probably need to emit this as
159 EmitConstant(DispOp.getImm()+ImmOffset, Size, CurByte, OS);
163 // If we have an immoffset, add it to the expression.
164 const MCExpr *Expr = DispOp.getExpr();
166 // If the fixup is pc-relative, we need to bias the value to be relative to
167 // the start of the field, not the end of the field.
168 if (FixupKind == MCFixupKind(X86::reloc_pcrel_4byte) ||
169 FixupKind == MCFixupKind(X86::reloc_riprel_4byte))
171 if (FixupKind == MCFixupKind(X86::reloc_pcrel_1byte))
175 Expr = MCBinaryExpr::CreateAdd(Expr, MCConstantExpr::Create(ImmOffset, Ctx),
178 // Emit a symbolic constant as a fixup and 4 zeros.
179 Fixups.push_back(MCFixup::Create(CurByte, Expr, FixupKind));
180 EmitConstant(0, Size, CurByte, OS);
184 void X86MCCodeEmitter::EmitMemModRMByte(const MCInst &MI, unsigned Op,
185 unsigned RegOpcodeField,
186 unsigned TSFlags, unsigned &CurByte,
188 SmallVectorImpl<MCFixup> &Fixups) const{
189 const MCOperand &Disp = MI.getOperand(Op+3);
190 const MCOperand &Base = MI.getOperand(Op);
191 const MCOperand &Scale = MI.getOperand(Op+1);
192 const MCOperand &IndexReg = MI.getOperand(Op+2);
193 unsigned BaseReg = Base.getReg();
195 // Handle %rip relative addressing.
196 if (BaseReg == X86::RIP) { // [disp32+RIP] in X86-64 mode
197 assert(IndexReg.getReg() == 0 && Is64BitMode &&
198 "Invalid rip-relative address");
199 EmitByte(ModRMByte(0, RegOpcodeField, 5), CurByte, OS);
201 unsigned FixupKind = X86::reloc_riprel_4byte;
203 // movq loads are handled with a special relocation form which allows the
204 // linker to eliminate some loads for GOT references which end up in the
205 // same linkage unit.
206 if (MI.getOpcode() == X86::MOV64rm_TC)
207 FixupKind = X86::reloc_riprel_4byte_movq_load;
209 // rip-relative addressing is actually relative to the *next* instruction.
210 // Since an immediate can follow the mod/rm byte for an instruction, this
211 // means that we need to bias the immediate field of the instruction with
212 // the size of the immediate field. If we have this case, add it into the
213 // expression to emit.
214 int ImmSize = X86II::hasImm(TSFlags) ? X86II::getSizeOfImm(TSFlags) : 0;
216 EmitImmediate(Disp, 4, MCFixupKind(FixupKind),
217 CurByte, OS, Fixups, -ImmSize);
221 unsigned BaseRegNo = BaseReg ? GetX86RegNum(Base) : -1U;
223 // Determine whether a SIB byte is needed.
224 // If no BaseReg, issue a RIP relative instruction only if the MCE can
225 // resolve addresses on-the-fly, otherwise use SIB (Intel Manual 2A, table
226 // 2-7) and absolute references.
228 if (// The SIB byte must be used if there is an index register.
229 IndexReg.getReg() == 0 &&
230 // The SIB byte must be used if the base is ESP/RSP/R12, all of which
231 // encode to an R/M value of 4, which indicates that a SIB byte is
233 BaseRegNo != N86::ESP &&
234 // If there is no base register and we're in 64-bit mode, we need a SIB
235 // byte to emit an addr that is just 'disp32' (the non-RIP relative form).
236 (!Is64BitMode || BaseReg != 0)) {
238 if (BaseReg == 0) { // [disp32] in X86-32 mode
239 EmitByte(ModRMByte(0, RegOpcodeField, 5), CurByte, OS);
240 EmitImmediate(Disp, 4, FK_Data_4, CurByte, OS, Fixups);
244 // If the base is not EBP/ESP and there is no displacement, use simple
245 // indirect register encoding, this handles addresses like [EAX]. The
246 // encoding for [EBP] with no displacement means [disp32] so we handle it
247 // by emitting a displacement of 0 below.
248 if (Disp.isImm() && Disp.getImm() == 0 && BaseRegNo != N86::EBP) {
249 EmitByte(ModRMByte(0, RegOpcodeField, BaseRegNo), CurByte, OS);
253 // Otherwise, if the displacement fits in a byte, encode as [REG+disp8].
254 if (Disp.isImm() && isDisp8(Disp.getImm())) {
255 EmitByte(ModRMByte(1, RegOpcodeField, BaseRegNo), CurByte, OS);
256 EmitImmediate(Disp, 1, FK_Data_1, CurByte, OS, Fixups);
260 // Otherwise, emit the most general non-SIB encoding: [REG+disp32]
261 EmitByte(ModRMByte(2, RegOpcodeField, BaseRegNo), CurByte, OS);
262 EmitImmediate(Disp, 4, FK_Data_4, CurByte, OS, Fixups);
266 // We need a SIB byte, so start by outputting the ModR/M byte first
267 assert(IndexReg.getReg() != X86::ESP &&
268 IndexReg.getReg() != X86::RSP && "Cannot use ESP as index reg!");
270 bool ForceDisp32 = false;
271 bool ForceDisp8 = false;
273 // If there is no base register, we emit the special case SIB byte with
274 // MOD=0, BASE=5, to JUST get the index, scale, and displacement.
275 EmitByte(ModRMByte(0, RegOpcodeField, 4), CurByte, OS);
277 } else if (!Disp.isImm()) {
278 // Emit the normal disp32 encoding.
279 EmitByte(ModRMByte(2, RegOpcodeField, 4), CurByte, OS);
281 } else if (Disp.getImm() == 0 && BaseReg != X86::EBP) {
282 // Emit no displacement ModR/M byte
283 EmitByte(ModRMByte(0, RegOpcodeField, 4), CurByte, OS);
284 } else if (isDisp8(Disp.getImm())) {
285 // Emit the disp8 encoding.
286 EmitByte(ModRMByte(1, RegOpcodeField, 4), CurByte, OS);
287 ForceDisp8 = true; // Make sure to force 8 bit disp if Base=EBP
289 // Emit the normal disp32 encoding.
290 EmitByte(ModRMByte(2, RegOpcodeField, 4), CurByte, OS);
293 // Calculate what the SS field value should be...
294 static const unsigned SSTable[] = { ~0, 0, 1, ~0, 2, ~0, ~0, ~0, 3 };
295 unsigned SS = SSTable[Scale.getImm()];
298 // Handle the SIB byte for the case where there is no base, see Intel
299 // Manual 2A, table 2-7. The displacement has already been output.
301 if (IndexReg.getReg())
302 IndexRegNo = GetX86RegNum(IndexReg);
303 else // Examples: [ESP+1*<noreg>+4] or [scaled idx]+disp32 (MOD=0,BASE=5)
305 EmitSIBByte(SS, IndexRegNo, 5, CurByte, OS);
308 if (IndexReg.getReg())
309 IndexRegNo = GetX86RegNum(IndexReg);
311 IndexRegNo = 4; // For example [ESP+1*<noreg>+4]
312 EmitSIBByte(SS, IndexRegNo, GetX86RegNum(Base), CurByte, OS);
315 // Do we need to output a displacement?
317 EmitImmediate(Disp, 1, FK_Data_1, CurByte, OS, Fixups);
318 else if (ForceDisp32 || Disp.getImm() != 0)
319 EmitImmediate(Disp, 4, FK_Data_4, CurByte, OS, Fixups);
322 /// DetermineREXPrefix - Determine if the MCInst has to be encoded with a X86-64
323 /// REX prefix which specifies 1) 64-bit instructions, 2) non-default operand
324 /// size, and 3) use of X86-64 extended registers.
325 static unsigned DetermineREXPrefix(const MCInst &MI, unsigned TSFlags,
326 const TargetInstrDesc &Desc) {
327 // Pseudo instructions never have a rex byte.
328 if ((TSFlags & X86II::FormMask) == X86II::Pseudo)
332 if (TSFlags & X86II::REX_W)
335 if (MI.getNumOperands() == 0) return REX;
337 unsigned NumOps = MI.getNumOperands();
338 // FIXME: MCInst should explicitize the two-addrness.
339 bool isTwoAddr = NumOps > 1 &&
340 Desc.getOperandConstraint(1, TOI::TIED_TO) != -1;
342 // If it accesses SPL, BPL, SIL, or DIL, then it requires a 0x40 REX prefix.
343 unsigned i = isTwoAddr ? 1 : 0;
344 for (; i != NumOps; ++i) {
345 const MCOperand &MO = MI.getOperand(i);
346 if (!MO.isReg()) continue;
347 unsigned Reg = MO.getReg();
348 if (!X86InstrInfo::isX86_64NonExtLowByteReg(Reg)) continue;
349 // FIXME: The caller of DetermineREXPrefix slaps this prefix onto anything
350 // that returns non-zero.
355 switch (TSFlags & X86II::FormMask) {
356 case X86II::MRMInitReg: assert(0 && "FIXME: Remove this!");
357 case X86II::MRMSrcReg:
358 if (MI.getOperand(0).isReg() &&
359 X86InstrInfo::isX86_64ExtendedReg(MI.getOperand(0).getReg()))
361 i = isTwoAddr ? 2 : 1;
362 for (; i != NumOps; ++i) {
363 const MCOperand &MO = MI.getOperand(i);
364 if (MO.isReg() && X86InstrInfo::isX86_64ExtendedReg(MO.getReg()))
368 case X86II::MRMSrcMem: {
369 if (MI.getOperand(0).isReg() &&
370 X86InstrInfo::isX86_64ExtendedReg(MI.getOperand(0).getReg()))
373 i = isTwoAddr ? 2 : 1;
374 for (; i != NumOps; ++i) {
375 const MCOperand &MO = MI.getOperand(i);
377 if (X86InstrInfo::isX86_64ExtendedReg(MO.getReg()))
384 case X86II::MRM0m: case X86II::MRM1m:
385 case X86II::MRM2m: case X86II::MRM3m:
386 case X86II::MRM4m: case X86II::MRM5m:
387 case X86II::MRM6m: case X86II::MRM7m:
388 case X86II::MRMDestMem: {
389 unsigned e = (isTwoAddr ? X86AddrNumOperands+1 : X86AddrNumOperands);
390 i = isTwoAddr ? 1 : 0;
391 if (NumOps > e && MI.getOperand(e).isReg() &&
392 X86InstrInfo::isX86_64ExtendedReg(MI.getOperand(e).getReg()))
395 for (; i != e; ++i) {
396 const MCOperand &MO = MI.getOperand(i);
398 if (X86InstrInfo::isX86_64ExtendedReg(MO.getReg()))
406 if (MI.getOperand(0).isReg() &&
407 X86InstrInfo::isX86_64ExtendedReg(MI.getOperand(0).getReg()))
409 i = isTwoAddr ? 2 : 1;
410 for (unsigned e = NumOps; i != e; ++i) {
411 const MCOperand &MO = MI.getOperand(i);
412 if (MO.isReg() && X86InstrInfo::isX86_64ExtendedReg(MO.getReg()))
420 void X86MCCodeEmitter::
421 EncodeInstruction(const MCInst &MI, raw_ostream &OS,
422 SmallVectorImpl<MCFixup> &Fixups) const {
423 unsigned Opcode = MI.getOpcode();
424 const TargetInstrDesc &Desc = TII.get(Opcode);
425 unsigned TSFlags = Desc.TSFlags;
427 // Keep track of the current byte being emitted.
428 unsigned CurByte = 0;
430 // FIXME: We should emit the prefixes in exactly the same order as GAS does,
431 // in order to provide diffability.
433 // Emit the lock opcode prefix as needed.
434 if (TSFlags & X86II::LOCK)
435 EmitByte(0xF0, CurByte, OS);
437 // Emit segment override opcode prefix as needed.
438 switch (TSFlags & X86II::SegOvrMask) {
439 default: assert(0 && "Invalid segment!");
440 case 0: break; // No segment override!
442 EmitByte(0x64, CurByte, OS);
445 EmitByte(0x65, CurByte, OS);
449 // Emit the repeat opcode prefix as needed.
450 if ((TSFlags & X86II::Op0Mask) == X86II::REP)
451 EmitByte(0xF3, CurByte, OS);
453 // Emit the operand size opcode prefix as needed.
454 if (TSFlags & X86II::OpSize)
455 EmitByte(0x66, CurByte, OS);
457 // Emit the address size opcode prefix as needed.
458 if (TSFlags & X86II::AdSize)
459 EmitByte(0x67, CurByte, OS);
461 bool Need0FPrefix = false;
462 switch (TSFlags & X86II::Op0Mask) {
463 default: assert(0 && "Invalid prefix!");
464 case 0: break; // No prefix!
465 case X86II::REP: break; // already handled.
466 case X86II::TB: // Two-byte opcode prefix
467 case X86II::T8: // 0F 38
468 case X86II::TA: // 0F 3A
471 case X86II::TF: // F2 0F 38
472 EmitByte(0xF2, CurByte, OS);
475 case X86II::XS: // F3 0F
476 EmitByte(0xF3, CurByte, OS);
479 case X86II::XD: // F2 0F
480 EmitByte(0xF2, CurByte, OS);
483 case X86II::D8: EmitByte(0xD8, CurByte, OS); break;
484 case X86II::D9: EmitByte(0xD9, CurByte, OS); break;
485 case X86II::DA: EmitByte(0xDA, CurByte, OS); break;
486 case X86II::DB: EmitByte(0xDB, CurByte, OS); break;
487 case X86II::DC: EmitByte(0xDC, CurByte, OS); break;
488 case X86II::DD: EmitByte(0xDD, CurByte, OS); break;
489 case X86II::DE: EmitByte(0xDE, CurByte, OS); break;
490 case X86II::DF: EmitByte(0xDF, CurByte, OS); break;
493 // Handle REX prefix.
494 // FIXME: Can this come before F2 etc to simplify emission?
496 if (unsigned REX = DetermineREXPrefix(MI, TSFlags, Desc))
497 EmitByte(0x40 | REX, CurByte, OS);
500 // 0x0F escape code must be emitted just before the opcode.
502 EmitByte(0x0F, CurByte, OS);
504 // FIXME: Pull this up into previous switch if REX can be moved earlier.
505 switch (TSFlags & X86II::Op0Mask) {
506 case X86II::TF: // F2 0F 38
507 case X86II::T8: // 0F 38
508 EmitByte(0x38, CurByte, OS);
510 case X86II::TA: // 0F 3A
511 EmitByte(0x3A, CurByte, OS);
515 // If this is a two-address instruction, skip one of the register operands.
516 unsigned NumOps = Desc.getNumOperands();
518 if (NumOps > 1 && Desc.getOperandConstraint(1, TOI::TIED_TO) != -1)
520 else if (NumOps > 2 && Desc.getOperandConstraint(NumOps-1, TOI::TIED_TO)== 0)
521 // Skip the last source operand that is tied_to the dest reg. e.g. LXADD32
524 unsigned char BaseOpcode = X86II::getBaseOpcodeFor(TSFlags);
525 switch (TSFlags & X86II::FormMask) {
526 case X86II::MRMInitReg:
527 assert(0 && "FIXME: Remove this form when the JIT moves to MCCodeEmitter!");
528 default: errs() << "FORM: " << (TSFlags & X86II::FormMask) << "\n";
529 assert(0 && "Unknown FormMask value in X86MCCodeEmitter!");
530 case X86II::Pseudo: return; // Pseudo instructions encode to nothing.
532 EmitByte(BaseOpcode, CurByte, OS);
535 case X86II::AddRegFrm:
536 EmitByte(BaseOpcode + GetX86RegNum(MI.getOperand(CurOp++)), CurByte, OS);
539 case X86II::MRMDestReg:
540 EmitByte(BaseOpcode, CurByte, OS);
541 EmitRegModRMByte(MI.getOperand(CurOp),
542 GetX86RegNum(MI.getOperand(CurOp+1)), CurByte, OS);
546 case X86II::MRMDestMem:
547 EmitByte(BaseOpcode, CurByte, OS);
548 EmitMemModRMByte(MI, CurOp,
549 GetX86RegNum(MI.getOperand(CurOp + X86AddrNumOperands)),
550 TSFlags, CurByte, OS, Fixups);
551 CurOp += X86AddrNumOperands + 1;
554 case X86II::MRMSrcReg:
555 EmitByte(BaseOpcode, CurByte, OS);
556 EmitRegModRMByte(MI.getOperand(CurOp+1), GetX86RegNum(MI.getOperand(CurOp)),
561 case X86II::MRMSrcMem: {
562 EmitByte(BaseOpcode, CurByte, OS);
564 // FIXME: Maybe lea should have its own form? This is a horrible hack.
566 if (Opcode == X86::LEA64r || Opcode == X86::LEA64_32r ||
567 Opcode == X86::LEA16r || Opcode == X86::LEA32r)
568 AddrOperands = X86AddrNumOperands - 1; // No segment register
570 AddrOperands = X86AddrNumOperands;
572 EmitMemModRMByte(MI, CurOp+1, GetX86RegNum(MI.getOperand(CurOp)),
573 TSFlags, CurByte, OS, Fixups);
574 CurOp += AddrOperands + 1;
578 case X86II::MRM0r: case X86II::MRM1r:
579 case X86II::MRM2r: case X86II::MRM3r:
580 case X86II::MRM4r: case X86II::MRM5r:
581 case X86II::MRM6r: case X86II::MRM7r:
582 EmitByte(BaseOpcode, CurByte, OS);
583 EmitRegModRMByte(MI.getOperand(CurOp++),
584 (TSFlags & X86II::FormMask)-X86II::MRM0r,
587 case X86II::MRM0m: case X86II::MRM1m:
588 case X86II::MRM2m: case X86II::MRM3m:
589 case X86II::MRM4m: case X86II::MRM5m:
590 case X86II::MRM6m: case X86II::MRM7m:
591 EmitByte(BaseOpcode, CurByte, OS);
592 EmitMemModRMByte(MI, CurOp, (TSFlags & X86II::FormMask)-X86II::MRM0m,
593 TSFlags, CurByte, OS, Fixups);
594 CurOp += X86AddrNumOperands;
597 EmitByte(BaseOpcode, CurByte, OS);
598 EmitByte(0xC1, CurByte, OS);
601 EmitByte(BaseOpcode, CurByte, OS);
602 EmitByte(0xC2, CurByte, OS);
605 EmitByte(BaseOpcode, CurByte, OS);
606 EmitByte(0xC3, CurByte, OS);
609 EmitByte(BaseOpcode, CurByte, OS);
610 EmitByte(0xC4, CurByte, OS);
613 EmitByte(BaseOpcode, CurByte, OS);
614 EmitByte(0xC8, CurByte, OS);
617 EmitByte(BaseOpcode, CurByte, OS);
618 EmitByte(0xC9, CurByte, OS);
621 EmitByte(BaseOpcode, CurByte, OS);
622 EmitByte(0xE8, CurByte, OS);
625 EmitByte(BaseOpcode, CurByte, OS);
626 EmitByte(0xF0, CurByte, OS);
629 EmitByte(BaseOpcode, CurByte, OS);
630 EmitByte(0xF8, CurByte, OS);
633 EmitByte(BaseOpcode, CurByte, OS);
634 EmitByte(0xF9, CurByte, OS);
638 // If there is a remaining operand, it must be a trailing immediate. Emit it
639 // according to the right size for the instruction.
641 EmitImmediate(MI.getOperand(CurOp++),
642 X86II::getSizeOfImm(TSFlags), getImmFixupKind(TSFlags),
643 CurByte, OS, Fixups);
647 if (/*!Desc.isVariadic() &&*/ CurOp != NumOps) {
648 errs() << "Cannot encode all operands of: ";