1 //===-- X86/X86CodeEmitter.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 contains the pass that transforms the X86 machine instructions into
11 // relocatable machine code.
13 //===----------------------------------------------------------------------===//
15 #define DEBUG_TYPE "x86-emitter"
16 #include "X86InstrInfo.h"
17 #include "X86JITInfo.h"
18 #include "X86Subtarget.h"
19 #include "X86TargetMachine.h"
20 #include "X86Relocations.h"
22 #include "llvm/LLVMContext.h"
23 #include "llvm/PassManager.h"
24 #include "llvm/CodeGen/JITCodeEmitter.h"
25 #include "llvm/CodeGen/MachineFunctionPass.h"
26 #include "llvm/CodeGen/MachineInstr.h"
27 #include "llvm/CodeGen/MachineModuleInfo.h"
28 #include "llvm/CodeGen/Passes.h"
29 #include "llvm/Function.h"
30 #include "llvm/ADT/Statistic.h"
31 #include "llvm/MC/MCCodeEmitter.h"
32 #include "llvm/MC/MCExpr.h"
33 #include "llvm/MC/MCInst.h"
34 #include "llvm/Support/Debug.h"
35 #include "llvm/Support/ErrorHandling.h"
36 #include "llvm/Support/raw_ostream.h"
37 #include "llvm/Target/TargetOptions.h"
40 STATISTIC(NumEmitted, "Number of machine instructions emitted");
43 template<class CodeEmitter>
44 class Emitter : public MachineFunctionPass {
45 const X86InstrInfo *II;
49 intptr_t PICBaseOffset;
54 explicit Emitter(X86TargetMachine &tm, CodeEmitter &mce)
55 : MachineFunctionPass(&ID), II(0), TD(0), TM(tm),
56 MCE(mce), PICBaseOffset(0), Is64BitMode(false),
57 IsPIC(TM.getRelocationModel() == Reloc::PIC_) {}
58 Emitter(X86TargetMachine &tm, CodeEmitter &mce,
59 const X86InstrInfo &ii, const TargetData &td, bool is64)
60 : MachineFunctionPass(&ID), II(&ii), TD(&td), TM(tm),
61 MCE(mce), PICBaseOffset(0), Is64BitMode(is64),
62 IsPIC(TM.getRelocationModel() == Reloc::PIC_) {}
64 bool runOnMachineFunction(MachineFunction &MF);
66 virtual const char *getPassName() const {
67 return "X86 Machine Code Emitter";
70 void emitInstruction(const MachineInstr &MI,
71 const TargetInstrDesc *Desc);
73 void getAnalysisUsage(AnalysisUsage &AU) const {
75 AU.addRequired<MachineModuleInfo>();
76 MachineFunctionPass::getAnalysisUsage(AU);
80 void emitPCRelativeBlockAddress(MachineBasicBlock *MBB);
81 void emitGlobalAddress(GlobalValue *GV, unsigned Reloc,
82 intptr_t Disp = 0, intptr_t PCAdj = 0,
83 bool Indirect = false);
84 void emitExternalSymbolAddress(const char *ES, unsigned Reloc);
85 void emitConstPoolAddress(unsigned CPI, unsigned Reloc, intptr_t Disp = 0,
87 void emitJumpTableAddress(unsigned JTI, unsigned Reloc,
90 void emitDisplacementField(const MachineOperand *RelocOp, int DispVal,
91 intptr_t Adj = 0, bool IsPCRel = true);
93 void emitRegModRMByte(unsigned ModRMReg, unsigned RegOpcodeField);
94 void emitRegModRMByte(unsigned RegOpcodeField);
95 void emitSIBByte(unsigned SS, unsigned Index, unsigned Base);
96 void emitConstant(uint64_t Val, unsigned Size);
98 void emitMemModRMByte(const MachineInstr &MI,
99 unsigned Op, unsigned RegOpcodeField,
102 unsigned getX86RegNum(unsigned RegNo) const;
105 template<class CodeEmitter>
106 char Emitter<CodeEmitter>::ID = 0;
107 } // end anonymous namespace.
109 /// createX86CodeEmitterPass - Return a pass that emits the collected X86 code
110 /// to the specified templated MachineCodeEmitter object.
111 FunctionPass *llvm::createX86JITCodeEmitterPass(X86TargetMachine &TM,
112 JITCodeEmitter &JCE) {
113 return new Emitter<JITCodeEmitter>(TM, JCE);
116 template<class CodeEmitter>
117 bool Emitter<CodeEmitter>::runOnMachineFunction(MachineFunction &MF) {
119 MCE.setModuleInfo(&getAnalysis<MachineModuleInfo>());
121 II = TM.getInstrInfo();
122 TD = TM.getTargetData();
123 Is64BitMode = TM.getSubtarget<X86Subtarget>().is64Bit();
124 IsPIC = TM.getRelocationModel() == Reloc::PIC_;
127 DEBUG(dbgs() << "JITTing function '"
128 << MF.getFunction()->getName() << "'\n");
129 MCE.startFunction(MF);
130 for (MachineFunction::iterator MBB = MF.begin(), E = MF.end();
132 MCE.StartMachineBasicBlock(MBB);
133 for (MachineBasicBlock::const_iterator I = MBB->begin(), E = MBB->end();
135 const TargetInstrDesc &Desc = I->getDesc();
136 emitInstruction(*I, &Desc);
137 // MOVPC32r is basically a call plus a pop instruction.
138 if (Desc.getOpcode() == X86::MOVPC32r)
139 emitInstruction(*I, &II->get(X86::POP32r));
140 NumEmitted++; // Keep track of the # of mi's emitted
143 } while (MCE.finishFunction(MF));
148 /// emitPCRelativeBlockAddress - This method keeps track of the information
149 /// necessary to resolve the address of this block later and emits a dummy
152 template<class CodeEmitter>
153 void Emitter<CodeEmitter>::emitPCRelativeBlockAddress(MachineBasicBlock *MBB) {
154 // Remember where this reference was and where it is to so we can
155 // deal with it later.
156 MCE.addRelocation(MachineRelocation::getBB(MCE.getCurrentPCOffset(),
157 X86::reloc_pcrel_word, MBB));
161 /// emitGlobalAddress - Emit the specified address to the code stream assuming
162 /// this is part of a "take the address of a global" instruction.
164 template<class CodeEmitter>
165 void Emitter<CodeEmitter>::emitGlobalAddress(GlobalValue *GV, unsigned Reloc,
166 intptr_t Disp /* = 0 */,
167 intptr_t PCAdj /* = 0 */,
168 bool Indirect /* = false */) {
169 intptr_t RelocCST = Disp;
170 if (Reloc == X86::reloc_picrel_word)
171 RelocCST = PICBaseOffset;
172 else if (Reloc == X86::reloc_pcrel_word)
174 MachineRelocation MR = Indirect
175 ? MachineRelocation::getIndirectSymbol(MCE.getCurrentPCOffset(), Reloc,
177 : MachineRelocation::getGV(MCE.getCurrentPCOffset(), Reloc,
178 GV, RelocCST, false);
179 MCE.addRelocation(MR);
180 // The relocated value will be added to the displacement
181 if (Reloc == X86::reloc_absolute_dword)
182 MCE.emitDWordLE(Disp);
184 MCE.emitWordLE((int32_t)Disp);
187 /// emitExternalSymbolAddress - Arrange for the address of an external symbol to
188 /// be emitted to the current location in the function, and allow it to be PC
190 template<class CodeEmitter>
191 void Emitter<CodeEmitter>::emitExternalSymbolAddress(const char *ES,
193 intptr_t RelocCST = (Reloc == X86::reloc_picrel_word) ? PICBaseOffset : 0;
195 // X86 never needs stubs because instruction selection will always pick
196 // an instruction sequence that is large enough to hold any address
198 // (see X86ISelLowering.cpp, near 2039: X86TargetLowering::LowerCall)
199 bool NeedStub = false;
200 MCE.addRelocation(MachineRelocation::getExtSym(MCE.getCurrentPCOffset(),
203 if (Reloc == X86::reloc_absolute_dword)
209 /// emitConstPoolAddress - Arrange for the address of an constant pool
210 /// to be emitted to the current location in the function, and allow it to be PC
212 template<class CodeEmitter>
213 void Emitter<CodeEmitter>::emitConstPoolAddress(unsigned CPI, unsigned Reloc,
214 intptr_t Disp /* = 0 */,
215 intptr_t PCAdj /* = 0 */) {
216 intptr_t RelocCST = 0;
217 if (Reloc == X86::reloc_picrel_word)
218 RelocCST = PICBaseOffset;
219 else if (Reloc == X86::reloc_pcrel_word)
221 MCE.addRelocation(MachineRelocation::getConstPool(MCE.getCurrentPCOffset(),
222 Reloc, CPI, RelocCST));
223 // The relocated value will be added to the displacement
224 if (Reloc == X86::reloc_absolute_dword)
225 MCE.emitDWordLE(Disp);
227 MCE.emitWordLE((int32_t)Disp);
230 /// emitJumpTableAddress - Arrange for the address of a jump table to
231 /// be emitted to the current location in the function, and allow it to be PC
233 template<class CodeEmitter>
234 void Emitter<CodeEmitter>::emitJumpTableAddress(unsigned JTI, unsigned Reloc,
235 intptr_t PCAdj /* = 0 */) {
236 intptr_t RelocCST = 0;
237 if (Reloc == X86::reloc_picrel_word)
238 RelocCST = PICBaseOffset;
239 else if (Reloc == X86::reloc_pcrel_word)
241 MCE.addRelocation(MachineRelocation::getJumpTable(MCE.getCurrentPCOffset(),
242 Reloc, JTI, RelocCST));
243 // The relocated value will be added to the displacement
244 if (Reloc == X86::reloc_absolute_dword)
250 template<class CodeEmitter>
251 unsigned Emitter<CodeEmitter>::getX86RegNum(unsigned RegNo) const {
252 return X86RegisterInfo::getX86RegNum(RegNo);
255 inline static unsigned char ModRMByte(unsigned Mod, unsigned RegOpcode,
257 assert(Mod < 4 && RegOpcode < 8 && RM < 8 && "ModRM Fields out of range!");
258 return RM | (RegOpcode << 3) | (Mod << 6);
261 template<class CodeEmitter>
262 void Emitter<CodeEmitter>::emitRegModRMByte(unsigned ModRMReg,
263 unsigned RegOpcodeFld){
264 MCE.emitByte(ModRMByte(3, RegOpcodeFld, getX86RegNum(ModRMReg)));
267 template<class CodeEmitter>
268 void Emitter<CodeEmitter>::emitRegModRMByte(unsigned RegOpcodeFld) {
269 MCE.emitByte(ModRMByte(3, RegOpcodeFld, 0));
272 template<class CodeEmitter>
273 void Emitter<CodeEmitter>::emitSIBByte(unsigned SS,
276 // SIB byte is in the same format as the ModRMByte...
277 MCE.emitByte(ModRMByte(SS, Index, Base));
280 template<class CodeEmitter>
281 void Emitter<CodeEmitter>::emitConstant(uint64_t Val, unsigned Size) {
282 // Output the constant in little endian byte order...
283 for (unsigned i = 0; i != Size; ++i) {
284 MCE.emitByte(Val & 255);
289 /// isDisp8 - Return true if this signed displacement fits in a 8-bit
290 /// sign-extended field.
291 static bool isDisp8(int Value) {
292 return Value == (signed char)Value;
295 static bool gvNeedsNonLazyPtr(const MachineOperand &GVOp,
296 const TargetMachine &TM) {
297 // For Darwin-64, simulate the linktime GOT by using the same non-lazy-pointer
298 // mechanism as 32-bit mode.
299 if (TM.getSubtarget<X86Subtarget>().is64Bit() &&
300 !TM.getSubtarget<X86Subtarget>().isTargetDarwin())
303 // Return true if this is a reference to a stub containing the address of the
304 // global, not the global itself.
305 return isGlobalStubReference(GVOp.getTargetFlags());
308 template<class CodeEmitter>
309 void Emitter<CodeEmitter>::emitDisplacementField(const MachineOperand *RelocOp,
311 intptr_t Adj /* = 0 */,
312 bool IsPCRel /* = true */) {
313 // If this is a simple integer displacement that doesn't require a relocation,
316 emitConstant(DispVal, 4);
320 // Otherwise, this is something that requires a relocation. Emit it as such
322 unsigned RelocType = Is64BitMode ?
323 (IsPCRel ? X86::reloc_pcrel_word : X86::reloc_absolute_word_sext)
324 : (IsPIC ? X86::reloc_picrel_word : X86::reloc_absolute_word);
325 if (RelocOp->isGlobal()) {
326 // In 64-bit static small code model, we could potentially emit absolute.
327 // But it's probably not beneficial. If the MCE supports using RIP directly
328 // do it, otherwise fallback to absolute (this is determined by IsPCRel).
329 // 89 05 00 00 00 00 mov %eax,0(%rip) # PC-relative
330 // 89 04 25 00 00 00 00 mov %eax,0x0 # Absolute
331 bool Indirect = gvNeedsNonLazyPtr(*RelocOp, TM);
332 emitGlobalAddress(RelocOp->getGlobal(), RelocType, RelocOp->getOffset(),
334 } else if (RelocOp->isSymbol()) {
335 emitExternalSymbolAddress(RelocOp->getSymbolName(), RelocType);
336 } else if (RelocOp->isCPI()) {
337 emitConstPoolAddress(RelocOp->getIndex(), RelocType,
338 RelocOp->getOffset(), Adj);
340 assert(RelocOp->isJTI() && "Unexpected machine operand!");
341 emitJumpTableAddress(RelocOp->getIndex(), RelocType, Adj);
345 template<class CodeEmitter>
346 void Emitter<CodeEmitter>::emitMemModRMByte(const MachineInstr &MI,
347 unsigned Op,unsigned RegOpcodeField,
349 const MachineOperand &Op3 = MI.getOperand(Op+3);
351 const MachineOperand *DispForReloc = 0;
353 // Figure out what sort of displacement we have to handle here.
354 if (Op3.isGlobal()) {
356 } else if (Op3.isSymbol()) {
358 } else if (Op3.isCPI()) {
359 if (!MCE.earlyResolveAddresses() || Is64BitMode || IsPIC) {
362 DispVal += MCE.getConstantPoolEntryAddress(Op3.getIndex());
363 DispVal += Op3.getOffset();
365 } else if (Op3.isJTI()) {
366 if (!MCE.earlyResolveAddresses() || Is64BitMode || IsPIC) {
369 DispVal += MCE.getJumpTableEntryAddress(Op3.getIndex());
372 DispVal = Op3.getImm();
375 const MachineOperand &Base = MI.getOperand(Op);
376 const MachineOperand &Scale = MI.getOperand(Op+1);
377 const MachineOperand &IndexReg = MI.getOperand(Op+2);
379 unsigned BaseReg = Base.getReg();
381 // Indicate that the displacement will use an pcrel or absolute reference
382 // by default. MCEs able to resolve addresses on-the-fly use pcrel by default
383 // while others, unless explicit asked to use RIP, use absolute references.
384 bool IsPCRel = MCE.earlyResolveAddresses() ? true : false;
386 // Is a SIB byte needed?
387 // If no BaseReg, issue a RIP relative instruction only if the MCE can
388 // resolve addresses on-the-fly, otherwise use SIB (Intel Manual 2A, table
389 // 2-7) and absolute references.
390 unsigned BaseRegNo = -1U;
391 if (BaseReg != 0 && BaseReg != X86::RIP)
392 BaseRegNo = getX86RegNum(BaseReg);
394 if (// The SIB byte must be used if there is an index register.
395 IndexReg.getReg() == 0 &&
396 // The SIB byte must be used if the base is ESP/RSP/R12, all of which
397 // encode to an R/M value of 4, which indicates that a SIB byte is
399 BaseRegNo != N86::ESP &&
400 // If there is no base register and we're in 64-bit mode, we need a SIB
401 // byte to emit an addr that is just 'disp32' (the non-RIP relative form).
402 (!Is64BitMode || BaseReg != 0)) {
403 if (BaseReg == 0 || // [disp32] in X86-32 mode
404 BaseReg == X86::RIP) { // [disp32+RIP] in X86-64 mode
405 MCE.emitByte(ModRMByte(0, RegOpcodeField, 5));
406 emitDisplacementField(DispForReloc, DispVal, PCAdj, true);
410 // If the base is not EBP/ESP and there is no displacement, use simple
411 // indirect register encoding, this handles addresses like [EAX]. The
412 // encoding for [EBP] with no displacement means [disp32] so we handle it
413 // by emitting a displacement of 0 below.
414 if (!DispForReloc && DispVal == 0 && BaseRegNo != N86::EBP) {
415 MCE.emitByte(ModRMByte(0, RegOpcodeField, BaseRegNo));
419 // Otherwise, if the displacement fits in a byte, encode as [REG+disp8].
420 if (!DispForReloc && isDisp8(DispVal)) {
421 MCE.emitByte(ModRMByte(1, RegOpcodeField, BaseRegNo));
422 emitConstant(DispVal, 1);
426 // Otherwise, emit the most general non-SIB encoding: [REG+disp32]
427 MCE.emitByte(ModRMByte(2, RegOpcodeField, BaseRegNo));
428 emitDisplacementField(DispForReloc, DispVal, PCAdj, IsPCRel);
432 // Otherwise we need a SIB byte, so start by outputting the ModR/M byte first.
433 assert(IndexReg.getReg() != X86::ESP &&
434 IndexReg.getReg() != X86::RSP && "Cannot use ESP as index reg!");
436 bool ForceDisp32 = false;
437 bool ForceDisp8 = false;
439 // If there is no base register, we emit the special case SIB byte with
440 // MOD=0, BASE=4, to JUST get the index, scale, and displacement.
441 MCE.emitByte(ModRMByte(0, RegOpcodeField, 4));
443 } else if (DispForReloc) {
444 // Emit the normal disp32 encoding.
445 MCE.emitByte(ModRMByte(2, RegOpcodeField, 4));
447 } else if (DispVal == 0 && getX86RegNum(BaseReg) != N86::EBP) {
448 // Emit no displacement ModR/M byte
449 MCE.emitByte(ModRMByte(0, RegOpcodeField, 4));
450 } else if (isDisp8(DispVal)) {
451 // Emit the disp8 encoding...
452 MCE.emitByte(ModRMByte(1, RegOpcodeField, 4));
453 ForceDisp8 = true; // Make sure to force 8 bit disp if Base=EBP
455 // Emit the normal disp32 encoding...
456 MCE.emitByte(ModRMByte(2, RegOpcodeField, 4));
459 // Calculate what the SS field value should be...
460 static const unsigned SSTable[] = { ~0, 0, 1, ~0, 2, ~0, ~0, ~0, 3 };
461 unsigned SS = SSTable[Scale.getImm()];
464 // Handle the SIB byte for the case where there is no base, see Intel
465 // Manual 2A, table 2-7. The displacement has already been output.
467 if (IndexReg.getReg())
468 IndexRegNo = getX86RegNum(IndexReg.getReg());
469 else // Examples: [ESP+1*<noreg>+4] or [scaled idx]+disp32 (MOD=0,BASE=5)
471 emitSIBByte(SS, IndexRegNo, 5);
473 unsigned BaseRegNo = getX86RegNum(BaseReg);
475 if (IndexReg.getReg())
476 IndexRegNo = getX86RegNum(IndexReg.getReg());
478 IndexRegNo = 4; // For example [ESP+1*<noreg>+4]
479 emitSIBByte(SS, IndexRegNo, BaseRegNo);
482 // Do we need to output a displacement?
484 emitConstant(DispVal, 1);
485 } else if (DispVal != 0 || ForceDisp32) {
486 emitDisplacementField(DispForReloc, DispVal, PCAdj, IsPCRel);
490 template<class CodeEmitter>
491 void Emitter<CodeEmitter>::emitInstruction(const MachineInstr &MI,
492 const TargetInstrDesc *Desc) {
495 MCE.processDebugLoc(MI.getDebugLoc(), true);
497 unsigned Opcode = Desc->Opcode;
499 // Emit the lock opcode prefix as needed.
500 if (Desc->TSFlags & X86II::LOCK)
503 // Emit segment override opcode prefix as needed.
504 switch (Desc->TSFlags & X86II::SegOvrMask) {
511 default: llvm_unreachable("Invalid segment!");
512 case 0: break; // No segment override!
515 // Emit the repeat opcode prefix as needed.
516 if ((Desc->TSFlags & X86II::Op0Mask) == X86II::REP)
519 // Emit the operand size opcode prefix as needed.
520 if (Desc->TSFlags & X86II::OpSize)
523 // Emit the address size opcode prefix as needed.
524 if (Desc->TSFlags & X86II::AdSize)
527 bool Need0FPrefix = false;
528 switch (Desc->TSFlags & X86II::Op0Mask) {
529 case X86II::TB: // Two-byte opcode prefix
530 case X86II::T8: // 0F 38
531 case X86II::TA: // 0F 3A
534 case X86II::TF: // F2 0F 38
538 case X86II::REP: break; // already handled.
539 case X86II::XS: // F3 0F
543 case X86II::XD: // F2 0F
547 case X86II::D8: case X86II::D9: case X86II::DA: case X86II::DB:
548 case X86II::DC: case X86II::DD: case X86II::DE: case X86II::DF:
550 (((Desc->TSFlags & X86II::Op0Mask)-X86II::D8)
551 >> X86II::Op0Shift));
552 break; // Two-byte opcode prefix
553 default: llvm_unreachable("Invalid prefix!");
554 case 0: break; // No prefix!
557 // Handle REX prefix.
559 if (unsigned REX = X86InstrInfo::determineREX(MI))
560 MCE.emitByte(0x40 | REX);
563 // 0x0F escape code must be emitted just before the opcode.
567 switch (Desc->TSFlags & X86II::Op0Mask) {
568 case X86II::TF: // F2 0F 38
569 case X86II::T8: // 0F 38
572 case X86II::TA: // 0F 3A
577 // If this is a two-address instruction, skip one of the register operands.
578 unsigned NumOps = Desc->getNumOperands();
580 if (NumOps > 1 && Desc->getOperandConstraint(1, TOI::TIED_TO) != -1)
582 else if (NumOps > 2 && Desc->getOperandConstraint(NumOps-1, TOI::TIED_TO)== 0)
583 // Skip the last source operand that is tied_to the dest reg. e.g. LXADD32
586 unsigned char BaseOpcode = X86II::getBaseOpcodeFor(Desc->TSFlags);
587 switch (Desc->TSFlags & X86II::FormMask) {
589 llvm_unreachable("Unknown FormMask value in X86 MachineCodeEmitter!");
591 // Remember the current PC offset, this is the PIC relocation
595 llvm_unreachable("psuedo instructions should be removed before code"
598 case TargetOpcode::INLINEASM:
599 // We allow inline assembler nodes with empty bodies - they can
600 // implicitly define registers, which is ok for JIT.
601 if (MI.getOperand(0).getSymbolName()[0])
602 llvm_report_error("JIT does not support inline asm!");
604 case TargetOpcode::DBG_LABEL:
605 case TargetOpcode::EH_LABEL:
606 case TargetOpcode::GC_LABEL:
607 MCE.emitLabel(MI.getOperand(0).getImm());
609 case TargetOpcode::IMPLICIT_DEF:
610 case TargetOpcode::KILL:
611 case X86::FP_REG_KILL:
613 case X86::MOVPC32r: {
614 // This emits the "call" portion of this pseudo instruction.
615 MCE.emitByte(BaseOpcode);
616 emitConstant(0, X86II::getSizeOfImm(Desc->TSFlags));
617 // Remember PIC base.
618 PICBaseOffset = (intptr_t) MCE.getCurrentPCOffset();
619 X86JITInfo *JTI = TM.getJITInfo();
620 JTI->setPICBase(MCE.getCurrentPCValue());
626 case X86II::RawFrm: {
627 MCE.emitByte(BaseOpcode);
632 const MachineOperand &MO = MI.getOperand(CurOp++);
634 DEBUG(dbgs() << "RawFrm CurOp " << CurOp << "\n");
635 DEBUG(dbgs() << "isMBB " << MO.isMBB() << "\n");
636 DEBUG(dbgs() << "isGlobal " << MO.isGlobal() << "\n");
637 DEBUG(dbgs() << "isSymbol " << MO.isSymbol() << "\n");
638 DEBUG(dbgs() << "isImm " << MO.isImm() << "\n");
641 emitPCRelativeBlockAddress(MO.getMBB());
646 emitGlobalAddress(MO.getGlobal(), X86::reloc_pcrel_word,
652 emitExternalSymbolAddress(MO.getSymbolName(), X86::reloc_pcrel_word);
656 // FIXME: Only used by hackish MCCodeEmitter, remove when dead.
658 emitJumpTableAddress(MO.getIndex(), X86::reloc_pcrel_word);
662 assert(MO.isImm() && "Unknown RawFrm operand!");
663 if (Opcode == X86::CALLpcrel32 || Opcode == X86::CALL64pcrel32) {
664 // Fix up immediate operand for pc relative calls.
665 intptr_t Imm = (intptr_t)MO.getImm();
666 Imm = Imm - MCE.getCurrentPCValue() - 4;
667 emitConstant(Imm, X86II::getSizeOfImm(Desc->TSFlags));
669 emitConstant(MO.getImm(), X86II::getSizeOfImm(Desc->TSFlags));
673 case X86II::AddRegFrm: {
674 MCE.emitByte(BaseOpcode + getX86RegNum(MI.getOperand(CurOp++).getReg()));
679 const MachineOperand &MO1 = MI.getOperand(CurOp++);
680 unsigned Size = X86II::getSizeOfImm(Desc->TSFlags);
682 emitConstant(MO1.getImm(), Size);
686 unsigned rt = Is64BitMode ? X86::reloc_pcrel_word
687 : (IsPIC ? X86::reloc_picrel_word : X86::reloc_absolute_word);
688 if (Opcode == X86::MOV64ri64i32)
689 rt = X86::reloc_absolute_word; // FIXME: add X86II flag?
690 // This should not occur on Darwin for relocatable objects.
691 if (Opcode == X86::MOV64ri)
692 rt = X86::reloc_absolute_dword; // FIXME: add X86II flag?
693 if (MO1.isGlobal()) {
694 bool Indirect = gvNeedsNonLazyPtr(MO1, TM);
695 emitGlobalAddress(MO1.getGlobal(), rt, MO1.getOffset(), 0,
697 } else if (MO1.isSymbol())
698 emitExternalSymbolAddress(MO1.getSymbolName(), rt);
699 else if (MO1.isCPI())
700 emitConstPoolAddress(MO1.getIndex(), rt);
701 else if (MO1.isJTI())
702 emitJumpTableAddress(MO1.getIndex(), rt);
706 case X86II::MRMDestReg: {
707 MCE.emitByte(BaseOpcode);
708 emitRegModRMByte(MI.getOperand(CurOp).getReg(),
709 getX86RegNum(MI.getOperand(CurOp+1).getReg()));
712 emitConstant(MI.getOperand(CurOp++).getImm(),
713 X86II::getSizeOfImm(Desc->TSFlags));
716 case X86II::MRMDestMem: {
717 MCE.emitByte(BaseOpcode);
718 emitMemModRMByte(MI, CurOp,
719 getX86RegNum(MI.getOperand(CurOp + X86AddrNumOperands)
721 CurOp += X86AddrNumOperands + 1;
723 emitConstant(MI.getOperand(CurOp++).getImm(),
724 X86II::getSizeOfImm(Desc->TSFlags));
728 case X86II::MRMSrcReg:
729 MCE.emitByte(BaseOpcode);
730 emitRegModRMByte(MI.getOperand(CurOp+1).getReg(),
731 getX86RegNum(MI.getOperand(CurOp).getReg()));
734 emitConstant(MI.getOperand(CurOp++).getImm(),
735 X86II::getSizeOfImm(Desc->TSFlags));
738 case X86II::MRMSrcMem: {
739 // FIXME: Maybe lea should have its own form?
741 if (Opcode == X86::LEA64r || Opcode == X86::LEA64_32r ||
742 Opcode == X86::LEA16r || Opcode == X86::LEA32r)
743 AddrOperands = X86AddrNumOperands - 1; // No segment register
745 AddrOperands = X86AddrNumOperands;
747 intptr_t PCAdj = (CurOp + AddrOperands + 1 != NumOps) ?
748 X86II::getSizeOfImm(Desc->TSFlags) : 0;
750 MCE.emitByte(BaseOpcode);
751 emitMemModRMByte(MI, CurOp+1, getX86RegNum(MI.getOperand(CurOp).getReg()),
753 CurOp += AddrOperands + 1;
755 emitConstant(MI.getOperand(CurOp++).getImm(),
756 X86II::getSizeOfImm(Desc->TSFlags));
760 case X86II::MRM0r: case X86II::MRM1r:
761 case X86II::MRM2r: case X86II::MRM3r:
762 case X86II::MRM4r: case X86II::MRM5r:
763 case X86II::MRM6r: case X86II::MRM7r: {
764 MCE.emitByte(BaseOpcode);
766 // Special handling of lfence, mfence, monitor, and mwait.
767 if (Desc->getOpcode() == X86::LFENCE ||
768 Desc->getOpcode() == X86::MFENCE ||
769 Desc->getOpcode() == X86::MONITOR ||
770 Desc->getOpcode() == X86::MWAIT) {
771 emitRegModRMByte((Desc->TSFlags & X86II::FormMask)-X86II::MRM0r);
773 switch (Desc->getOpcode()) {
783 emitRegModRMByte(MI.getOperand(CurOp++).getReg(),
784 (Desc->TSFlags & X86II::FormMask)-X86II::MRM0r);
790 const MachineOperand &MO1 = MI.getOperand(CurOp++);
791 unsigned Size = X86II::getSizeOfImm(Desc->TSFlags);
793 emitConstant(MO1.getImm(), Size);
797 unsigned rt = Is64BitMode ? X86::reloc_pcrel_word
798 : (IsPIC ? X86::reloc_picrel_word : X86::reloc_absolute_word);
799 if (Opcode == X86::MOV64ri32)
800 rt = X86::reloc_absolute_word_sext; // FIXME: add X86II flag?
801 if (MO1.isGlobal()) {
802 bool Indirect = gvNeedsNonLazyPtr(MO1, TM);
803 emitGlobalAddress(MO1.getGlobal(), rt, MO1.getOffset(), 0,
805 } else if (MO1.isSymbol())
806 emitExternalSymbolAddress(MO1.getSymbolName(), rt);
807 else if (MO1.isCPI())
808 emitConstPoolAddress(MO1.getIndex(), rt);
809 else if (MO1.isJTI())
810 emitJumpTableAddress(MO1.getIndex(), rt);
814 case X86II::MRM0m: case X86II::MRM1m:
815 case X86II::MRM2m: case X86II::MRM3m:
816 case X86II::MRM4m: case X86II::MRM5m:
817 case X86II::MRM6m: case X86II::MRM7m: {
818 intptr_t PCAdj = (CurOp + X86AddrNumOperands != NumOps) ?
819 (MI.getOperand(CurOp+X86AddrNumOperands).isImm() ?
820 X86II::getSizeOfImm(Desc->TSFlags) : 4) : 0;
822 MCE.emitByte(BaseOpcode);
823 emitMemModRMByte(MI, CurOp, (Desc->TSFlags & X86II::FormMask)-X86II::MRM0m,
825 CurOp += X86AddrNumOperands;
830 const MachineOperand &MO = MI.getOperand(CurOp++);
831 unsigned Size = X86II::getSizeOfImm(Desc->TSFlags);
833 emitConstant(MO.getImm(), Size);
837 unsigned rt = Is64BitMode ? X86::reloc_pcrel_word
838 : (IsPIC ? X86::reloc_picrel_word : X86::reloc_absolute_word);
839 if (Opcode == X86::MOV64mi32)
840 rt = X86::reloc_absolute_word_sext; // FIXME: add X86II flag?
842 bool Indirect = gvNeedsNonLazyPtr(MO, TM);
843 emitGlobalAddress(MO.getGlobal(), rt, MO.getOffset(), 0,
845 } else if (MO.isSymbol())
846 emitExternalSymbolAddress(MO.getSymbolName(), rt);
848 emitConstPoolAddress(MO.getIndex(), rt);
850 emitJumpTableAddress(MO.getIndex(), rt);
854 case X86II::MRMInitReg:
855 MCE.emitByte(BaseOpcode);
856 // Duplicate register, used by things like MOV8r0 (aka xor reg,reg).
857 emitRegModRMByte(MI.getOperand(CurOp).getReg(),
858 getX86RegNum(MI.getOperand(CurOp).getReg()));
863 if (!Desc->isVariadic() && CurOp != NumOps) {
865 dbgs() << "Cannot encode all operands of: " << MI << "\n";
870 MCE.processDebugLoc(MI.getDebugLoc(), false);
873 // Adapt the Emitter / CodeEmitter interfaces to MCCodeEmitter.
875 // FIXME: This is a total hack designed to allow work on llvm-mc to proceed
876 // without being blocked on various cleanups needed to support a clean interface
877 // to instruction encoding.
881 #include "llvm/DerivedTypes.h"
884 class MCSingleInstructionCodeEmitter : public MachineCodeEmitter {
886 const MCInst *CurrentInst;
887 SmallVectorImpl<MCFixup> *FixupList;
890 MCSingleInstructionCodeEmitter() { reset(0, 0); }
892 void reset(const MCInst *Inst, SmallVectorImpl<MCFixup> *Fixups) {
896 BufferEnd = array_endof(Data);
901 return StringRef(reinterpret_cast<char*>(BufferBegin),
902 CurBufferPtr - BufferBegin);
905 virtual void startFunction(MachineFunction &F) {}
906 virtual bool finishFunction(MachineFunction &F) { return false; }
907 virtual void StartMachineBasicBlock(MachineBasicBlock *MBB) {}
908 virtual bool earlyResolveAddresses() const { return false; }
909 virtual void addRelocation(const MachineRelocation &MR) {
910 unsigned Offset = 0, OpIndex = 0, Kind = MR.getRelocationType();
912 // This form is only used in one case, for branches.
913 if (MR.isBasicBlock()) {
914 Offset = unsigned(MR.getMachineCodeOffset());
917 assert(MR.isJumpTableIndex() && "Unexpected relocation!");
919 Offset = unsigned(MR.getMachineCodeOffset());
921 // The operand index is encoded as the first byte of the fake operand.
922 OpIndex = MR.getJumpTableIndex();
925 MCOperand Op = CurrentInst->getOperand(OpIndex);
926 assert(Op.isExpr() && "FIXME: Not yet implemented!");
927 FixupList->push_back(MCFixup::Create(Offset, Op.getExpr(),
928 MCFixupKind(FirstTargetFixupKind + Kind)));
930 virtual void setModuleInfo(MachineModuleInfo* Info) {}
932 // Interface functions which should never get called in our usage.
934 virtual void emitLabel(uint64_t LabelID) {
935 assert(0 && "Unexpected code emitter call!");
937 virtual uintptr_t getConstantPoolEntryAddress(unsigned Index) const {
938 assert(0 && "Unexpected code emitter call!");
941 virtual uintptr_t getJumpTableEntryAddress(unsigned Index) const {
942 assert(0 && "Unexpected code emitter call!");
945 virtual uintptr_t getMachineBasicBlockAddress(MachineBasicBlock *MBB) const {
946 assert(0 && "Unexpected code emitter call!");
949 virtual uintptr_t getLabelAddress(uint64_t LabelID) const {
950 assert(0 && "Unexpected code emitter call!");
955 class X86MCCodeEmitter : public MCCodeEmitter {
956 X86MCCodeEmitter(const X86MCCodeEmitter &); // DO NOT IMPLEMENT
957 void operator=(const X86MCCodeEmitter &); // DO NOT IMPLEMENT
960 X86TargetMachine &TM;
961 llvm::Function *DummyF;
963 mutable llvm::MachineFunction *DummyMF;
964 llvm::MachineBasicBlock *DummyMBB;
966 MCSingleInstructionCodeEmitter *InstrEmitter;
967 Emitter<MachineCodeEmitter> *Emit;
970 X86MCCodeEmitter(X86TargetMachine &_TM) : TM(_TM) {
971 // Verily, thou shouldst avert thine eyes.
972 const llvm::FunctionType *FTy =
973 FunctionType::get(llvm::Type::getVoidTy(getGlobalContext()), false);
974 DummyF = Function::Create(FTy, GlobalValue::InternalLinkage);
975 DummyTD = new TargetData("");
976 DummyMF = new MachineFunction(DummyF, TM, 0);
977 DummyMBB = DummyMF->CreateMachineBasicBlock();
979 InstrEmitter = new MCSingleInstructionCodeEmitter();
980 Emit = new Emitter<MachineCodeEmitter>(TM, *InstrEmitter,
984 ~X86MCCodeEmitter() {
991 unsigned getNumFixupKinds() const {
995 MCFixupKindInfo &getFixupKindInfo(MCFixupKind Kind) const {
996 static MCFixupKindInfo Infos[] = {
997 { "reloc_pcrel_word", 0, 4 * 8 },
998 { "reloc_picrel_word", 0, 4 * 8 },
999 { "reloc_absolute_word", 0, 4 * 8 },
1000 { "reloc_absolute_word_sext", 0, 4 * 8 },
1001 { "reloc_absolute_dword", 0, 8 * 8 }
1004 assert(Kind >= FirstTargetFixupKind && Kind < MaxTargetFixupKind &&
1006 return Infos[Kind - FirstTargetFixupKind];
1009 bool AddRegToInstr(const MCInst &MI, MachineInstr *Instr,
1010 unsigned Start) const {
1011 if (Start + 1 > MI.getNumOperands())
1014 const MCOperand &Op = MI.getOperand(Start);
1015 if (!Op.isReg()) return false;
1017 Instr->addOperand(MachineOperand::CreateReg(Op.getReg(), false));
1021 bool AddImmToInstr(const MCInst &MI, MachineInstr *Instr,
1022 unsigned Start) const {
1023 if (Start + 1 > MI.getNumOperands())
1026 const MCOperand &Op = MI.getOperand(Start);
1028 Instr->addOperand(MachineOperand::CreateImm(Op.getImm()));
1034 const MCExpr *Expr = Op.getExpr();
1035 if (const MCConstantExpr *CE = dyn_cast<MCConstantExpr>(Expr)) {
1036 Instr->addOperand(MachineOperand::CreateImm(CE->getValue()));
1040 // Fake this as an external symbol to the code emitter to add a relcoation
1041 // entry we will recognize.
1042 Instr->addOperand(MachineOperand::CreateJTI(Start, 0));
1046 bool AddLMemToInstr(const MCInst &MI, MachineInstr *Instr,
1047 unsigned Start) const {
1048 return (AddRegToInstr(MI, Instr, Start + 0) &&
1049 AddImmToInstr(MI, Instr, Start + 1) &&
1050 AddRegToInstr(MI, Instr, Start + 2) &&
1051 AddImmToInstr(MI, Instr, Start + 3));
1054 bool AddMemToInstr(const MCInst &MI, MachineInstr *Instr,
1055 unsigned Start) const {
1056 return (AddRegToInstr(MI, Instr, Start + 0) &&
1057 AddImmToInstr(MI, Instr, Start + 1) &&
1058 AddRegToInstr(MI, Instr, Start + 2) &&
1059 AddImmToInstr(MI, Instr, Start + 3) &&
1060 AddRegToInstr(MI, Instr, Start + 4));
1063 void EncodeInstruction(const MCInst &MI, raw_ostream &OS,
1064 SmallVectorImpl<MCFixup> &Fixups) const {
1067 // Convert the MCInst to a MachineInstr so we can (ab)use the regular
1069 const X86InstrInfo &II = *TM.getInstrInfo();
1070 const TargetInstrDesc &Desc = II.get(MI.getOpcode());
1071 MachineInstr *Instr = DummyMF->CreateMachineInstr(Desc, DebugLoc());
1072 DummyMBB->push_back(Instr);
1074 unsigned Opcode = MI.getOpcode();
1075 unsigned NumOps = MI.getNumOperands();
1077 bool AddTied = false;
1078 if (NumOps > 1 && Desc.getOperandConstraint(1, TOI::TIED_TO) != -1)
1080 else if (NumOps > 2 &&
1081 Desc.getOperandConstraint(NumOps-1, TOI::TIED_TO)== 0)
1082 // Skip the last source operand that is tied_to the dest reg. e.g. LXADD32
1086 switch (Desc.TSFlags & X86II::FormMask) {
1087 case X86II::MRMDestReg:
1088 case X86II::MRMSrcReg:
1089 // Matching doesn't fill this in completely, we have to choose operand 0
1090 // for a tied register.
1091 OK &= AddRegToInstr(MI, Instr, CurOp++);
1093 OK &= AddRegToInstr(MI, Instr, CurOp++ - 1);
1094 OK &= AddRegToInstr(MI, Instr, CurOp++);
1096 OK &= AddImmToInstr(MI, Instr, CurOp);
1100 if (CurOp < NumOps) {
1101 // Hack to make branches work.
1102 if (!(Desc.TSFlags & X86II::ImmMask) &&
1103 MI.getOperand(0).isExpr() &&
1104 isa<MCSymbolRefExpr>(MI.getOperand(0).getExpr()))
1105 Instr->addOperand(MachineOperand::CreateMBB(DummyMBB));
1107 OK &= AddImmToInstr(MI, Instr, CurOp);
1111 case X86II::AddRegFrm:
1112 // Matching doesn't fill this in completely, we have to choose operand 0
1113 // for a tied register.
1114 OK &= AddRegToInstr(MI, Instr, CurOp++);
1116 OK &= AddRegToInstr(MI, Instr, CurOp++ - 1);
1118 OK &= AddImmToInstr(MI, Instr, CurOp);
1121 case X86II::MRM0r: case X86II::MRM1r:
1122 case X86II::MRM2r: case X86II::MRM3r:
1123 case X86II::MRM4r: case X86II::MRM5r:
1124 case X86II::MRM6r: case X86II::MRM7r:
1125 // Matching doesn't fill this in completely, we have to choose operand 0
1126 // for a tied register.
1127 OK &= AddRegToInstr(MI, Instr, CurOp++);
1129 OK &= AddRegToInstr(MI, Instr, CurOp++ - 1);
1131 OK &= AddImmToInstr(MI, Instr, CurOp);
1134 case X86II::MRM0m: case X86II::MRM1m:
1135 case X86II::MRM2m: case X86II::MRM3m:
1136 case X86II::MRM4m: case X86II::MRM5m:
1137 case X86II::MRM6m: case X86II::MRM7m:
1138 OK &= AddMemToInstr(MI, Instr, CurOp); CurOp += 5;
1140 OK &= AddImmToInstr(MI, Instr, CurOp);
1143 case X86II::MRMSrcMem:
1144 // Matching doesn't fill this in completely, we have to choose operand 0
1145 // for a tied register.
1146 OK &= AddRegToInstr(MI, Instr, CurOp++);
1148 OK &= AddRegToInstr(MI, Instr, CurOp++ - 1);
1149 if (Opcode == X86::LEA64r || Opcode == X86::LEA64_32r ||
1150 Opcode == X86::LEA16r || Opcode == X86::LEA32r)
1151 OK &= AddLMemToInstr(MI, Instr, CurOp);
1153 OK &= AddMemToInstr(MI, Instr, CurOp);
1156 case X86II::MRMDestMem:
1157 OK &= AddMemToInstr(MI, Instr, CurOp); CurOp += 5;
1158 OK &= AddRegToInstr(MI, Instr, CurOp);
1162 case X86II::MRMInitReg:
1169 dbgs() << "couldn't convert inst '";
1171 dbgs() << "' to machine instr:\n";
1175 InstrEmitter->reset(&MI, &Fixups);
1177 Emit->emitInstruction(*Instr, &Desc);
1178 OS << InstrEmitter->str();
1180 Instr->eraseFromParent();
1185 #include "llvm/Support/CommandLine.h"
1187 static cl::opt<bool> EnableNewEncoder("enable-new-x86-encoder",
1191 // Ok, now you can look.
1192 MCCodeEmitter *llvm::createHeinousX86MCCodeEmitter(const Target &T,
1193 TargetMachine &TM) {
1195 // FIXME: Remove the heinous one when the new one works.
1196 if (EnableNewEncoder) {
1197 if (TM.getTargetData()->getPointerSize() == 4)
1198 return createX86_32MCCodeEmitter(T, TM);
1199 return createX86_64MCCodeEmitter(T, TM);
1202 return new X86MCCodeEmitter(static_cast<X86TargetMachine&>(TM));