1 //===-- X86ATTAsmPrinter.cpp - Convert X86 LLVM code to AT&T assembly -----===//
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 a printer that converts from our internal representation
11 // of machine-dependent LLVM code to AT&T format assembly
12 // language. This printer is the output mechanism used by `llc'.
14 //===----------------------------------------------------------------------===//
16 #define DEBUG_TYPE "asm-printer"
17 #include "X86ATTAsmPrinter.h"
20 #include "X86MachineFunctionInfo.h"
21 #include "X86TargetMachine.h"
22 #include "X86TargetAsmInfo.h"
23 #include "llvm/ADT/StringExtras.h"
24 #include "llvm/CallingConv.h"
25 #include "llvm/CodeGen/MachineJumpTableInfo.h"
26 #include "llvm/Module.h"
27 #include "llvm/Support/Mangler.h"
28 #include "llvm/Target/TargetAsmInfo.h"
29 #include "llvm/Target/TargetOptions.h"
30 #include "llvm/ADT/Statistic.h"
33 STATISTIC(EmittedInsts, "Number of machine instrs printed");
35 static std::string getPICLabelString(unsigned FnNum,
36 const TargetAsmInfo *TAI,
37 const X86Subtarget* Subtarget) {
39 if (Subtarget->isTargetDarwin())
40 label = "\"L" + utostr_32(FnNum) + "$pb\"";
41 else if (Subtarget->isTargetELF())
42 label = ".Lllvm$" + utostr_32(FnNum) + "." + "$piclabel";
44 assert(0 && "Don't know how to print PIC label!\n");
49 /// getSectionForFunction - Return the section that we should emit the
50 /// specified function body into.
51 std::string X86ATTAsmPrinter::getSectionForFunction(const Function &F) const {
52 switch (F.getLinkage()) {
53 default: assert(0 && "Unknown linkage type!");
54 case Function::InternalLinkage:
55 case Function::DLLExportLinkage:
56 case Function::ExternalLinkage:
57 return TAI->getTextSection();
58 case Function::WeakLinkage:
59 case Function::LinkOnceLinkage:
60 if (Subtarget->isTargetDarwin()) {
61 return ".section __TEXT,__textcoal_nt,coalesced,pure_instructions";
62 } else if (Subtarget->isTargetCygMing()) {
63 return "\t.section\t.text$linkonce." + CurrentFnName + ",\"ax\"";
65 return "\t.section\t.llvm.linkonce.t." + CurrentFnName +
71 /// runOnMachineFunction - This uses the printMachineInstruction()
72 /// method to print assembly for each instruction.
74 bool X86ATTAsmPrinter::runOnMachineFunction(MachineFunction &MF) {
75 if (TAI->doesSupportDebugInformation()) {
76 // Let PassManager know we need debug information and relay
77 // the MachineModuleInfo address on to DwarfWriter.
78 MMI = &getAnalysis<MachineModuleInfo>();
79 DW.SetModuleInfo(MMI);
82 SetupMachineFunction(MF);
85 // Print out constants referenced by the function
86 EmitConstantPool(MF.getConstantPool());
88 // Print out labels for the function.
89 const Function *F = MF.getFunction();
90 unsigned CC = F->getCallingConv();
92 // Populate function information map. Actually, We don't want to populate
93 // non-stdcall or non-fastcall functions' information right now.
94 if (CC == CallingConv::X86_StdCall || CC == CallingConv::X86_FastCall)
95 FunctionInfoMap[F] = *MF.getInfo<X86MachineFunctionInfo>();
97 X86SharedAsmPrinter::decorateName(CurrentFnName, F);
99 SwitchToTextSection(getSectionForFunction(*F).c_str(), F);
101 switch (F->getLinkage()) {
102 default: assert(0 && "Unknown linkage type!");
103 case Function::InternalLinkage: // Symbols default to internal.
106 case Function::DLLExportLinkage:
107 DLLExportedFns.insert(Mang->makeNameProper(F->getName(), ""));
109 case Function::ExternalLinkage:
111 O << "\t.globl\t" << CurrentFnName << "\n";
113 case Function::LinkOnceLinkage:
114 case Function::WeakLinkage:
116 if (Subtarget->isTargetDarwin()) {
117 O << "\t.globl\t" << CurrentFnName << "\n";
118 O << TAI->getWeakDefDirective() << CurrentFnName << "\n";
119 } else if (Subtarget->isTargetCygMing()) {
120 O << "\t.globl\t" << CurrentFnName << "\n";
121 O << "\t.linkonce discard\n";
123 O << "\t.weak\t" << CurrentFnName << "\n";
127 if (F->hasHiddenVisibility()) {
128 if (const char *Directive = TAI->getHiddenDirective())
129 O << Directive << CurrentFnName << "\n";
130 } else if (F->hasProtectedVisibility()) {
131 if (const char *Directive = TAI->getProtectedDirective())
132 O << Directive << CurrentFnName << "\n";
135 if (Subtarget->isTargetELF())
136 O << "\t.type\t" << CurrentFnName << ",@function\n";
137 else if (Subtarget->isTargetCygMing()) {
138 O << "\t.def\t " << CurrentFnName
140 (F->getLinkage() == Function::InternalLinkage ? COFF::C_STAT : COFF::C_EXT)
141 << ";\t.type\t" << (COFF::DT_FCN << COFF::N_BTSHFT)
145 O << CurrentFnName << ":\n";
146 // Add some workaround for linkonce linkage on Cygwin\MinGW
147 if (Subtarget->isTargetCygMing() &&
148 (F->getLinkage() == Function::LinkOnceLinkage ||
149 F->getLinkage() == Function::WeakLinkage))
150 O << "Lllvm$workaround$fake$stub$" << CurrentFnName << ":\n";
152 if (TAI->doesSupportDebugInformation()) {
153 // Emit pre-function debug information.
154 DW.BeginFunction(&MF);
157 if (Subtarget->isTargetDarwin()) {
158 // If the function is empty, then we need to emit *something*. Otherwise,
159 // the function's label might be associated with something that it wasn't
160 // meant to be associated with. We emit a noop in this situation.
161 MachineFunction::iterator I = MF.begin();
163 if (++I == MF.end() && MF.front().empty())
167 // Print out code for the function.
168 for (MachineFunction::const_iterator I = MF.begin(), E = MF.end();
170 // Print a label for the basic block.
171 if (!I->pred_empty()) {
172 printBasicBlockLabel(I, true, true);
175 for (MachineBasicBlock::const_iterator II = I->begin(), IE = I->end();
177 // Print the assembly for the instruction.
178 printMachineInstruction(II);
182 if (TAI->hasDotTypeDotSizeDirective())
183 O << "\t.size\t" << CurrentFnName << ", .-" << CurrentFnName << "\n";
185 if (TAI->doesSupportDebugInformation()) {
186 // Emit post-function debug information.
190 // Print out jump tables referenced by the function.
191 EmitJumpTableInfo(MF.getJumpTableInfo(), MF);
193 // We didn't modify anything.
197 static inline bool printGOT(TargetMachine &TM, const X86Subtarget* ST) {
198 return ST->isPICStyleGOT() && TM.getRelocationModel() == Reloc::PIC_;
201 static inline bool printStub(TargetMachine &TM, const X86Subtarget* ST) {
202 return ST->isPICStyleStub() && TM.getRelocationModel() != Reloc::Static;
205 void X86ATTAsmPrinter::printOperand(const MachineInstr *MI, unsigned OpNo,
206 const char *Modifier, bool NotRIPRel) {
207 const MachineOperand &MO = MI->getOperand(OpNo);
208 const TargetRegisterInfo &RI = *TM.getRegisterInfo();
209 switch (MO.getType()) {
210 case MachineOperand::MO_Register: {
211 assert(TargetRegisterInfo::isPhysicalRegister(MO.getReg()) &&
212 "Virtual registers should not make it this far!");
214 unsigned Reg = MO.getReg();
215 if (Modifier && strncmp(Modifier, "subreg", strlen("subreg")) == 0) {
216 MVT::ValueType VT = (strcmp(Modifier+6,"64") == 0) ?
217 MVT::i64 : ((strcmp(Modifier+6, "32") == 0) ? MVT::i32 :
218 ((strcmp(Modifier+6,"16") == 0) ? MVT::i16 : MVT::i8));
219 Reg = getX86SubSuperRegister(Reg, VT);
221 for (const char *Name = RI.get(Reg).AsmName; *Name; ++Name)
222 O << (char)tolower(*Name);
226 case MachineOperand::MO_Immediate:
228 (strcmp(Modifier, "debug") && strcmp(Modifier, "mem")))
232 case MachineOperand::MO_MachineBasicBlock:
233 printBasicBlockLabel(MO.getMBB());
235 case MachineOperand::MO_JumpTableIndex: {
236 bool isMemOp = Modifier && !strcmp(Modifier, "mem");
237 if (!isMemOp) O << '$';
238 O << TAI->getPrivateGlobalPrefix() << "JTI" << getFunctionNumber() << "_"
241 if (TM.getRelocationModel() == Reloc::PIC_) {
242 if (Subtarget->isPICStyleStub())
243 O << "-\"" << TAI->getPrivateGlobalPrefix() << getFunctionNumber()
245 else if (Subtarget->isPICStyleGOT())
249 if (isMemOp && Subtarget->isPICStyleRIPRel() && !NotRIPRel)
253 case MachineOperand::MO_ConstantPoolIndex: {
254 bool isMemOp = Modifier && !strcmp(Modifier, "mem");
255 if (!isMemOp) O << '$';
256 O << TAI->getPrivateGlobalPrefix() << "CPI" << getFunctionNumber() << "_"
259 if (TM.getRelocationModel() == Reloc::PIC_) {
260 if (Subtarget->isPICStyleStub())
261 O << "-\"" << TAI->getPrivateGlobalPrefix() << getFunctionNumber()
263 else if (Subtarget->isPICStyleGOT())
267 int Offset = MO.getOffset();
273 if (isMemOp && Subtarget->isPICStyleRIPRel() && !NotRIPRel)
277 case MachineOperand::MO_GlobalAddress: {
278 bool isCallOp = Modifier && !strcmp(Modifier, "call");
279 bool isMemOp = Modifier && !strcmp(Modifier, "mem");
280 bool needCloseParen = false;
282 GlobalValue *GV = MO.getGlobal();
283 GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV);
284 bool isThreadLocal = GVar && GVar->isThreadLocal();
286 std::string Name = Mang->getValueName(GV);
287 X86SharedAsmPrinter::decorateName(Name, GV);
289 if (!isMemOp && !isCallOp)
291 else if (Name[0] == '$') {
292 // The name begins with a dollar-sign. In order to avoid having it look
293 // like an integer immediate to the assembler, enclose it in parens.
295 needCloseParen = true;
298 if (printStub(TM, Subtarget)) {
299 // Link-once, declaration, or Weakly-linked global variables need
300 // non-lazily-resolved stubs
301 if (GV->isDeclaration() ||
302 GV->hasWeakLinkage() ||
303 GV->hasLinkOnceLinkage()) {
304 // Dynamically-resolved functions need a stub for the function.
305 if (isCallOp && isa<Function>(GV)) {
306 FnStubs.insert(Name);
307 O << TAI->getPrivateGlobalPrefix() << Name << "$stub";
309 GVStubs.insert(Name);
310 O << TAI->getPrivateGlobalPrefix() << Name << "$non_lazy_ptr";
313 if (GV->hasDLLImportLinkage())
318 if (!isCallOp && TM.getRelocationModel() == Reloc::PIC_)
319 O << '-' << getPICLabelString(getFunctionNumber(), TAI, Subtarget);
321 if (GV->hasDLLImportLinkage()) {
326 if (isCallOp && isa<Function>(GV)) {
327 if (printGOT(TM, Subtarget)) {
328 // Assemble call via PLT for non-local symbols
329 if (!(GV->hasHiddenVisibility() || GV->hasProtectedVisibility()) ||
333 if (Subtarget->isTargetCygMing() && GV->isDeclaration())
334 // Save function name for later type emission
335 FnStubs.insert(Name);
339 if (GV->hasExternalWeakLinkage())
340 ExtWeakSymbols.insert(GV);
342 int Offset = MO.getOffset();
349 if (TM.getRelocationModel() == Reloc::PIC_)
350 O << "@TLSGD"; // general dynamic TLS model
352 if (GV->isDeclaration())
353 O << "@INDNTPOFF"; // initial exec TLS model
355 O << "@NTPOFF"; // local exec TLS model
356 } else if (isMemOp) {
357 if (printGOT(TM, Subtarget)) {
358 if (Subtarget->GVRequiresExtraLoad(GV, TM, false))
362 } else if (Subtarget->isPICStyleRIPRel() && !NotRIPRel &&
363 TM.getRelocationModel() != Reloc::Static) {
364 if (Subtarget->GVRequiresExtraLoad(GV, TM, false))
367 if (needCloseParen) {
368 needCloseParen = false;
372 // Use rip when possible to reduce code size, except when
373 // index or base register are also part of the address. e.g.
374 // foo(%rip)(%rcx,%rax,4) is not legal
384 case MachineOperand::MO_ExternalSymbol: {
385 bool isCallOp = Modifier && !strcmp(Modifier, "call");
386 bool needCloseParen = false;
387 std::string Name(TAI->getGlobalPrefix());
388 Name += MO.getSymbolName();
389 if (isCallOp && printStub(TM, Subtarget)) {
390 FnStubs.insert(Name);
391 O << TAI->getPrivateGlobalPrefix() << Name << "$stub";
396 else if (Name[0] == '$') {
397 // The name begins with a dollar-sign. In order to avoid having it look
398 // like an integer immediate to the assembler, enclose it in parens.
400 needCloseParen = true;
405 if (printGOT(TM, Subtarget)) {
406 std::string GOTName(TAI->getGlobalPrefix());
407 GOTName+="_GLOBAL_OFFSET_TABLE_";
409 // HACK! Emit extra offset to PC during printing GOT offset to
410 // compensate for the size of popl instruction. The resulting code
414 // popl %some_register
415 // addl $_GLOBAL_ADDRESS_TABLE_ + [.-piclabel], %some_register
417 << getPICLabelString(getFunctionNumber(), TAI, Subtarget) << "]";
426 if (!isCallOp && Subtarget->isPICStyleRIPRel())
432 O << "<unknown operand type>"; return;
436 void X86ATTAsmPrinter::printSSECC(const MachineInstr *MI, unsigned Op) {
437 unsigned char value = MI->getOperand(Op).getImm();
438 assert(value <= 7 && "Invalid ssecc argument!");
440 case 0: O << "eq"; break;
441 case 1: O << "lt"; break;
442 case 2: O << "le"; break;
443 case 3: O << "unord"; break;
444 case 4: O << "neq"; break;
445 case 5: O << "nlt"; break;
446 case 6: O << "nle"; break;
447 case 7: O << "ord"; break;
451 void X86ATTAsmPrinter::printMemReference(const MachineInstr *MI, unsigned Op,
452 const char *Modifier){
453 assert(isMem(MI, Op) && "Invalid memory reference!");
454 MachineOperand BaseReg = MI->getOperand(Op);
455 MachineOperand IndexReg = MI->getOperand(Op+2);
456 const MachineOperand &DispSpec = MI->getOperand(Op+3);
458 bool NotRIPRel = IndexReg.getReg() || BaseReg.getReg();
459 if (DispSpec.isGlobalAddress() ||
460 DispSpec.isConstantPoolIndex() ||
461 DispSpec.isJumpTableIndex()) {
462 printOperand(MI, Op+3, "mem", NotRIPRel);
464 int DispVal = DispSpec.getImm();
465 if (DispVal || (!IndexReg.getReg() && !BaseReg.getReg()))
469 if (IndexReg.getReg() || BaseReg.getReg()) {
470 unsigned ScaleVal = MI->getOperand(Op+1).getImm();
471 unsigned BaseRegOperand = 0, IndexRegOperand = 2;
473 // There are cases where we can end up with ESP/RSP in the indexreg slot.
474 // If this happens, swap the base/index register to support assemblers that
475 // don't work when the index is *SP.
476 if (IndexReg.getReg() == X86::ESP || IndexReg.getReg() == X86::RSP) {
477 assert(ScaleVal == 1 && "Scale not supported for stack pointer!");
478 std::swap(BaseReg, IndexReg);
479 std::swap(BaseRegOperand, IndexRegOperand);
483 if (BaseReg.getReg())
484 printOperand(MI, Op+BaseRegOperand, Modifier);
486 if (IndexReg.getReg()) {
488 printOperand(MI, Op+IndexRegOperand, Modifier);
490 O << "," << ScaleVal;
496 void X86ATTAsmPrinter::printPICJumpTableSetLabel(unsigned uid,
497 const MachineBasicBlock *MBB) const {
498 if (!TAI->getSetDirective())
501 // We don't need .set machinery if we have GOT-style relocations
502 if (Subtarget->isPICStyleGOT())
505 O << TAI->getSetDirective() << ' ' << TAI->getPrivateGlobalPrefix()
506 << getFunctionNumber() << '_' << uid << "_set_" << MBB->getNumber() << ',';
507 printBasicBlockLabel(MBB, false, false, false);
508 if (Subtarget->isPICStyleRIPRel())
509 O << '-' << TAI->getPrivateGlobalPrefix() << "JTI" << getFunctionNumber()
510 << '_' << uid << '\n';
512 O << '-' << getPICLabelString(getFunctionNumber(), TAI, Subtarget) << '\n';
515 void X86ATTAsmPrinter::printPICLabel(const MachineInstr *MI, unsigned Op) {
516 std::string label = getPICLabelString(getFunctionNumber(), TAI, Subtarget);
517 O << label << "\n" << label << ":";
521 void X86ATTAsmPrinter::printPICJumpTableEntry(const MachineJumpTableInfo *MJTI,
522 const MachineBasicBlock *MBB,
525 const char *JTEntryDirective = MJTI->getEntrySize() == 4 ?
526 TAI->getData32bitsDirective() : TAI->getData64bitsDirective();
528 O << JTEntryDirective << ' ';
530 if (TM.getRelocationModel() == Reloc::PIC_) {
531 if (Subtarget->isPICStyleRIPRel() || Subtarget->isPICStyleStub()) {
532 O << TAI->getPrivateGlobalPrefix() << getFunctionNumber()
533 << '_' << uid << "_set_" << MBB->getNumber();
534 } else if (Subtarget->isPICStyleGOT()) {
535 printBasicBlockLabel(MBB, false, false, false);
538 assert(0 && "Don't know how to print MBB label for this PIC mode");
540 printBasicBlockLabel(MBB, false, false, false);
543 bool X86ATTAsmPrinter::printAsmMRegister(const MachineOperand &MO,
545 const TargetRegisterInfo &RI = *TM.getRegisterInfo();
546 unsigned Reg = MO.getReg();
548 default: return true; // Unknown mode.
549 case 'b': // Print QImode register
550 Reg = getX86SubSuperRegister(Reg, MVT::i8);
552 case 'h': // Print QImode high register
553 Reg = getX86SubSuperRegister(Reg, MVT::i8, true);
555 case 'w': // Print HImode register
556 Reg = getX86SubSuperRegister(Reg, MVT::i16);
558 case 'k': // Print SImode register
559 Reg = getX86SubSuperRegister(Reg, MVT::i32);
561 case 'q': // Print DImode register
562 Reg = getX86SubSuperRegister(Reg, MVT::i64);
567 for (const char *Name = RI.get(Reg).AsmName; *Name; ++Name)
568 O << (char)tolower(*Name);
572 /// PrintAsmOperand - Print out an operand for an inline asm expression.
574 bool X86ATTAsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
576 const char *ExtraCode) {
577 // Does this asm operand have a single letter operand modifier?
578 if (ExtraCode && ExtraCode[0]) {
579 if (ExtraCode[1] != 0) return true; // Unknown modifier.
581 switch (ExtraCode[0]) {
582 default: return true; // Unknown modifier.
583 case 'c': // Don't print "$" before a global var name or constant.
584 printOperand(MI, OpNo, "mem");
586 case 'b': // Print QImode register
587 case 'h': // Print QImode high register
588 case 'w': // Print HImode register
589 case 'k': // Print SImode register
590 case 'q': // Print DImode register
591 if (MI->getOperand(OpNo).isRegister())
592 return printAsmMRegister(MI->getOperand(OpNo), ExtraCode[0]);
593 printOperand(MI, OpNo);
596 case 'P': // Don't print @PLT, but do print as memory.
597 printOperand(MI, OpNo, "mem");
602 printOperand(MI, OpNo);
606 bool X86ATTAsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI,
609 const char *ExtraCode) {
610 if (ExtraCode && ExtraCode[0]) {
611 if (ExtraCode[1] != 0) return true; // Unknown modifier.
613 switch (ExtraCode[0]) {
614 default: return true; // Unknown modifier.
615 case 'b': // Print QImode register
616 case 'h': // Print QImode high register
617 case 'w': // Print HImode register
618 case 'k': // Print SImode register
619 case 'q': // Print SImode register
620 // These only apply to registers, ignore on mem.
624 printMemReference(MI, OpNo);
628 /// printMachineInstruction -- Print out a single X86 LLVM instruction
629 /// MI in AT&T syntax to the current output stream.
631 void X86ATTAsmPrinter::printMachineInstruction(const MachineInstr *MI) {
634 // See if a truncate instruction can be turned into a nop.
635 switch (MI->getOpcode()) {
637 case X86::PsMOVZX64rr32:
638 O << TAI->getCommentString() << " ZERO-EXTEND " << "\n\t";
642 // Call the autogenerated instruction printer routines.
643 printInstruction(MI);
646 // Include the auto-generated portion of the assembly writer.
647 #include "X86GenAsmWriter.inc"