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 unsigned FnAlign = OptimizeForSize ? 1 : 4;
102 switch (F->getLinkage()) {
103 default: assert(0 && "Unknown linkage type!");
104 case Function::InternalLinkage: // Symbols default to internal.
105 EmitAlignment(FnAlign, F);
107 case Function::DLLExportLinkage:
108 DLLExportedFns.insert(Mang->makeNameProper(F->getName(), ""));
110 case Function::ExternalLinkage:
111 EmitAlignment(FnAlign, F);
112 O << "\t.globl\t" << CurrentFnName << "\n";
114 case Function::LinkOnceLinkage:
115 case Function::WeakLinkage:
116 EmitAlignment(FnAlign, F);
117 if (Subtarget->isTargetDarwin()) {
118 O << "\t.globl\t" << CurrentFnName << "\n";
119 O << TAI->getWeakDefDirective() << CurrentFnName << "\n";
120 } else if (Subtarget->isTargetCygMing()) {
121 O << "\t.globl\t" << CurrentFnName << "\n";
122 O << "\t.linkonce discard\n";
124 O << "\t.weak\t" << CurrentFnName << "\n";
128 if (F->hasHiddenVisibility()) {
129 if (const char *Directive = TAI->getHiddenDirective())
130 O << Directive << CurrentFnName << "\n";
131 } else if (F->hasProtectedVisibility()) {
132 if (const char *Directive = TAI->getProtectedDirective())
133 O << Directive << CurrentFnName << "\n";
136 if (Subtarget->isTargetELF())
137 O << "\t.type\t" << CurrentFnName << ",@function\n";
138 else if (Subtarget->isTargetCygMing()) {
139 O << "\t.def\t " << CurrentFnName
141 (F->getLinkage() == Function::InternalLinkage ? COFF::C_STAT : COFF::C_EXT)
142 << ";\t.type\t" << (COFF::DT_FCN << COFF::N_BTSHFT)
146 O << CurrentFnName << ":\n";
147 // Add some workaround for linkonce linkage on Cygwin\MinGW
148 if (Subtarget->isTargetCygMing() &&
149 (F->getLinkage() == Function::LinkOnceLinkage ||
150 F->getLinkage() == Function::WeakLinkage))
151 O << "Lllvm$workaround$fake$stub$" << CurrentFnName << ":\n";
153 if (TAI->doesSupportDebugInformation() ||
154 TAI->doesSupportExceptionHandling()) {
155 // Emit pre-function debug and/or EH information.
156 DW.BeginFunction(&MF);
159 // Print out code for the function.
160 bool hasAnyRealCode = false;
161 for (MachineFunction::const_iterator I = MF.begin(), E = MF.end();
163 // Print a label for the basic block.
164 if (!I->pred_empty()) {
165 printBasicBlockLabel(I, true, true);
168 for (MachineBasicBlock::const_iterator II = I->begin(), IE = I->end();
170 // Print the assembly for the instruction.
171 if (II->getOpcode() != X86::LABEL)
172 hasAnyRealCode = true;
173 printMachineInstruction(II);
177 if (Subtarget->isTargetDarwin() && !hasAnyRealCode) {
178 // If the function is empty, then we need to emit *something*. Otherwise,
179 // the function's label might be associated with something that it wasn't
180 // meant to be associated with. We emit a noop in this situation.
181 // We are assuming inline asms are code.
185 if (TAI->hasDotTypeDotSizeDirective())
186 O << "\t.size\t" << CurrentFnName << ", .-" << CurrentFnName << "\n";
188 if (TAI->doesSupportDebugInformation()) {
189 // Emit post-function debug information.
193 // Print out jump tables referenced by the function.
194 EmitJumpTableInfo(MF.getJumpTableInfo(), MF);
196 // We didn't modify anything.
200 static inline bool printGOT(TargetMachine &TM, const X86Subtarget* ST) {
201 return ST->isPICStyleGOT() && TM.getRelocationModel() == Reloc::PIC_;
204 static inline bool printStub(TargetMachine &TM, const X86Subtarget* ST) {
205 return ST->isPICStyleStub() && TM.getRelocationModel() != Reloc::Static;
208 void X86ATTAsmPrinter::printOperand(const MachineInstr *MI, unsigned OpNo,
209 const char *Modifier, bool NotRIPRel) {
210 const MachineOperand &MO = MI->getOperand(OpNo);
211 switch (MO.getType()) {
212 case MachineOperand::MO_Register: {
213 assert(TargetRegisterInfo::isPhysicalRegister(MO.getReg()) &&
214 "Virtual registers should not make it this far!");
216 unsigned Reg = MO.getReg();
217 if (Modifier && strncmp(Modifier, "subreg", strlen("subreg")) == 0) {
218 MVT::ValueType VT = (strcmp(Modifier+6,"64") == 0) ?
219 MVT::i64 : ((strcmp(Modifier+6, "32") == 0) ? MVT::i32 :
220 ((strcmp(Modifier+6,"16") == 0) ? MVT::i16 : MVT::i8));
221 Reg = getX86SubSuperRegister(Reg, VT);
223 for (const char *Name = TRI->getAsmName(Reg); *Name; ++Name)
224 O << (char)tolower(*Name);
228 case MachineOperand::MO_Immediate:
230 (strcmp(Modifier, "debug") && strcmp(Modifier, "mem")))
234 case MachineOperand::MO_MachineBasicBlock:
235 printBasicBlockLabel(MO.getMBB());
237 case MachineOperand::MO_JumpTableIndex: {
238 bool isMemOp = Modifier && !strcmp(Modifier, "mem");
239 if (!isMemOp) O << '$';
240 O << TAI->getPrivateGlobalPrefix() << "JTI" << getFunctionNumber() << "_"
243 if (TM.getRelocationModel() == Reloc::PIC_) {
244 if (Subtarget->isPICStyleStub())
245 O << "-\"" << TAI->getPrivateGlobalPrefix() << getFunctionNumber()
247 else if (Subtarget->isPICStyleGOT())
251 if (isMemOp && Subtarget->isPICStyleRIPRel() && !NotRIPRel)
255 case MachineOperand::MO_ConstantPoolIndex: {
256 bool isMemOp = Modifier && !strcmp(Modifier, "mem");
257 if (!isMemOp) O << '$';
258 O << TAI->getPrivateGlobalPrefix() << "CPI" << getFunctionNumber() << "_"
261 if (TM.getRelocationModel() == Reloc::PIC_) {
262 if (Subtarget->isPICStyleStub())
263 O << "-\"" << TAI->getPrivateGlobalPrefix() << getFunctionNumber()
265 else if (Subtarget->isPICStyleGOT())
269 int Offset = MO.getOffset();
275 if (isMemOp && Subtarget->isPICStyleRIPRel() && !NotRIPRel)
279 case MachineOperand::MO_GlobalAddress: {
280 bool isCallOp = Modifier && !strcmp(Modifier, "call");
281 bool isMemOp = Modifier && !strcmp(Modifier, "mem");
282 bool needCloseParen = false;
284 const GlobalValue *GV = MO.getGlobal();
285 const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV);
287 // If GV is an alias then use the aliasee for determining
289 if (const GlobalAlias *GA = dyn_cast<GlobalAlias>(GV))
290 GVar = dyn_cast_or_null<GlobalVariable>(GA->resolveAliasedGlobal());
293 bool isThreadLocal = GVar && GVar->isThreadLocal();
295 std::string Name = Mang->getValueName(GV);
296 X86SharedAsmPrinter::decorateName(Name, GV);
298 if (!isMemOp && !isCallOp)
300 else if (Name[0] == '$') {
301 // The name begins with a dollar-sign. In order to avoid having it look
302 // like an integer immediate to the assembler, enclose it in parens.
304 needCloseParen = true;
307 if (printStub(TM, Subtarget)) {
308 // Link-once, declaration, or Weakly-linked global variables need
309 // non-lazily-resolved stubs
310 if (GV->isDeclaration() ||
311 GV->hasWeakLinkage() ||
312 GV->hasLinkOnceLinkage()) {
313 // Dynamically-resolved functions need a stub for the function.
314 if (isCallOp && isa<Function>(GV)) {
315 FnStubs.insert(Name);
316 O << TAI->getPrivateGlobalPrefix() << Name << "$stub";
318 GVStubs.insert(Name);
319 O << TAI->getPrivateGlobalPrefix() << Name << "$non_lazy_ptr";
322 if (GV->hasDLLImportLinkage())
327 if (!isCallOp && TM.getRelocationModel() == Reloc::PIC_)
328 O << '-' << getPICLabelString(getFunctionNumber(), TAI, Subtarget);
330 if (GV->hasDLLImportLinkage()) {
335 if (isCallOp && isa<Function>(GV)) {
336 if (printGOT(TM, Subtarget)) {
337 // Assemble call via PLT for non-local symbols
338 if (!(GV->hasHiddenVisibility() || GV->hasProtectedVisibility()) ||
342 if (Subtarget->isTargetCygMing() && GV->isDeclaration())
343 // Save function name for later type emission
344 FnStubs.insert(Name);
348 if (GV->hasExternalWeakLinkage())
349 ExtWeakSymbols.insert(GV);
351 int Offset = MO.getOffset();
358 if (TM.getRelocationModel() == Reloc::PIC_)
359 O << "@TLSGD"; // general dynamic TLS model
361 if (GV->isDeclaration())
362 O << "@INDNTPOFF"; // initial exec TLS model
364 O << "@NTPOFF"; // local exec TLS model
365 } else if (isMemOp) {
366 if (printGOT(TM, Subtarget)) {
367 if (Subtarget->GVRequiresExtraLoad(GV, TM, false))
371 } else if (Subtarget->isPICStyleRIPRel() && !NotRIPRel &&
372 TM.getRelocationModel() != Reloc::Static) {
373 if (Subtarget->GVRequiresExtraLoad(GV, TM, false))
376 if (needCloseParen) {
377 needCloseParen = false;
381 // Use rip when possible to reduce code size, except when
382 // index or base register are also part of the address. e.g.
383 // foo(%rip)(%rcx,%rax,4) is not legal
393 case MachineOperand::MO_ExternalSymbol: {
394 bool isCallOp = Modifier && !strcmp(Modifier, "call");
395 bool needCloseParen = false;
396 std::string Name(TAI->getGlobalPrefix());
397 Name += MO.getSymbolName();
398 if (isCallOp && printStub(TM, Subtarget)) {
399 FnStubs.insert(Name);
400 O << TAI->getPrivateGlobalPrefix() << Name << "$stub";
405 else if (Name[0] == '$') {
406 // The name begins with a dollar-sign. In order to avoid having it look
407 // like an integer immediate to the assembler, enclose it in parens.
409 needCloseParen = true;
414 if (printGOT(TM, Subtarget)) {
415 std::string GOTName(TAI->getGlobalPrefix());
416 GOTName+="_GLOBAL_OFFSET_TABLE_";
418 // HACK! Emit extra offset to PC during printing GOT offset to
419 // compensate for the size of popl instruction. The resulting code
423 // popl %some_register
424 // addl $_GLOBAL_ADDRESS_TABLE_ + [.-piclabel], %some_register
426 << getPICLabelString(getFunctionNumber(), TAI, Subtarget) << "]";
435 if (!isCallOp && Subtarget->isPICStyleRIPRel())
441 O << "<unknown operand type>"; return;
445 void X86ATTAsmPrinter::printSSECC(const MachineInstr *MI, unsigned Op) {
446 unsigned char value = MI->getOperand(Op).getImm();
447 assert(value <= 7 && "Invalid ssecc argument!");
449 case 0: O << "eq"; break;
450 case 1: O << "lt"; break;
451 case 2: O << "le"; break;
452 case 3: O << "unord"; break;
453 case 4: O << "neq"; break;
454 case 5: O << "nlt"; break;
455 case 6: O << "nle"; break;
456 case 7: O << "ord"; break;
460 void X86ATTAsmPrinter::printMemReference(const MachineInstr *MI, unsigned Op,
461 const char *Modifier){
462 assert(isMem(MI, Op) && "Invalid memory reference!");
463 MachineOperand BaseReg = MI->getOperand(Op);
464 MachineOperand IndexReg = MI->getOperand(Op+2);
465 const MachineOperand &DispSpec = MI->getOperand(Op+3);
467 bool NotRIPRel = IndexReg.getReg() || BaseReg.getReg();
468 if (DispSpec.isGlobalAddress() ||
469 DispSpec.isConstantPoolIndex() ||
470 DispSpec.isJumpTableIndex()) {
471 printOperand(MI, Op+3, "mem", NotRIPRel);
473 int DispVal = DispSpec.getImm();
474 if (DispVal || (!IndexReg.getReg() && !BaseReg.getReg()))
478 if (IndexReg.getReg() || BaseReg.getReg()) {
479 unsigned ScaleVal = MI->getOperand(Op+1).getImm();
480 unsigned BaseRegOperand = 0, IndexRegOperand = 2;
482 // There are cases where we can end up with ESP/RSP in the indexreg slot.
483 // If this happens, swap the base/index register to support assemblers that
484 // don't work when the index is *SP.
485 if (IndexReg.getReg() == X86::ESP || IndexReg.getReg() == X86::RSP) {
486 assert(ScaleVal == 1 && "Scale not supported for stack pointer!");
487 std::swap(BaseReg, IndexReg);
488 std::swap(BaseRegOperand, IndexRegOperand);
492 if (BaseReg.getReg())
493 printOperand(MI, Op+BaseRegOperand, Modifier);
495 if (IndexReg.getReg()) {
497 printOperand(MI, Op+IndexRegOperand, Modifier);
499 O << "," << ScaleVal;
505 void X86ATTAsmPrinter::printPICJumpTableSetLabel(unsigned uid,
506 const MachineBasicBlock *MBB) const {
507 if (!TAI->getSetDirective())
510 // We don't need .set machinery if we have GOT-style relocations
511 if (Subtarget->isPICStyleGOT())
514 O << TAI->getSetDirective() << ' ' << TAI->getPrivateGlobalPrefix()
515 << getFunctionNumber() << '_' << uid << "_set_" << MBB->getNumber() << ',';
516 printBasicBlockLabel(MBB, false, false, false);
517 if (Subtarget->isPICStyleRIPRel())
518 O << '-' << TAI->getPrivateGlobalPrefix() << "JTI" << getFunctionNumber()
519 << '_' << uid << '\n';
521 O << '-' << getPICLabelString(getFunctionNumber(), TAI, Subtarget) << '\n';
524 void X86ATTAsmPrinter::printPICLabel(const MachineInstr *MI, unsigned Op) {
525 std::string label = getPICLabelString(getFunctionNumber(), TAI, Subtarget);
526 O << label << "\n" << label << ":";
530 void X86ATTAsmPrinter::printPICJumpTableEntry(const MachineJumpTableInfo *MJTI,
531 const MachineBasicBlock *MBB,
534 const char *JTEntryDirective = MJTI->getEntrySize() == 4 ?
535 TAI->getData32bitsDirective() : TAI->getData64bitsDirective();
537 O << JTEntryDirective << ' ';
539 if (TM.getRelocationModel() == Reloc::PIC_) {
540 if (Subtarget->isPICStyleRIPRel() || Subtarget->isPICStyleStub()) {
541 O << TAI->getPrivateGlobalPrefix() << getFunctionNumber()
542 << '_' << uid << "_set_" << MBB->getNumber();
543 } else if (Subtarget->isPICStyleGOT()) {
544 printBasicBlockLabel(MBB, false, false, false);
547 assert(0 && "Don't know how to print MBB label for this PIC mode");
549 printBasicBlockLabel(MBB, false, false, false);
552 bool X86ATTAsmPrinter::printAsmMRegister(const MachineOperand &MO,
554 unsigned Reg = MO.getReg();
556 default: return true; // Unknown mode.
557 case 'b': // Print QImode register
558 Reg = getX86SubSuperRegister(Reg, MVT::i8);
560 case 'h': // Print QImode high register
561 Reg = getX86SubSuperRegister(Reg, MVT::i8, true);
563 case 'w': // Print HImode register
564 Reg = getX86SubSuperRegister(Reg, MVT::i16);
566 case 'k': // Print SImode register
567 Reg = getX86SubSuperRegister(Reg, MVT::i32);
569 case 'q': // Print DImode register
570 Reg = getX86SubSuperRegister(Reg, MVT::i64);
575 for (const char *Name = TRI->getAsmName(Reg); *Name; ++Name)
576 O << (char)tolower(*Name);
580 /// PrintAsmOperand - Print out an operand for an inline asm expression.
582 bool X86ATTAsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
584 const char *ExtraCode) {
585 // Does this asm operand have a single letter operand modifier?
586 if (ExtraCode && ExtraCode[0]) {
587 if (ExtraCode[1] != 0) return true; // Unknown modifier.
589 switch (ExtraCode[0]) {
590 default: return true; // Unknown modifier.
591 case 'c': // Don't print "$" before a global var name or constant.
592 printOperand(MI, OpNo, "mem");
594 case 'b': // Print QImode register
595 case 'h': // Print QImode high register
596 case 'w': // Print HImode register
597 case 'k': // Print SImode register
598 case 'q': // Print DImode register
599 if (MI->getOperand(OpNo).isRegister())
600 return printAsmMRegister(MI->getOperand(OpNo), ExtraCode[0]);
601 printOperand(MI, OpNo);
604 case 'P': // Don't print @PLT, but do print as memory.
605 printOperand(MI, OpNo, "mem");
610 printOperand(MI, OpNo);
614 bool X86ATTAsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI,
617 const char *ExtraCode) {
618 if (ExtraCode && ExtraCode[0]) {
619 if (ExtraCode[1] != 0) return true; // Unknown modifier.
621 switch (ExtraCode[0]) {
622 default: return true; // Unknown modifier.
623 case 'b': // Print QImode register
624 case 'h': // Print QImode high register
625 case 'w': // Print HImode register
626 case 'k': // Print SImode register
627 case 'q': // Print SImode register
628 // These only apply to registers, ignore on mem.
632 printMemReference(MI, OpNo);
636 /// printMachineInstruction -- Print out a single X86 LLVM instruction
637 /// MI in AT&T syntax to the current output stream.
639 void X86ATTAsmPrinter::printMachineInstruction(const MachineInstr *MI) {
642 // Call the autogenerated instruction printer routines.
643 printInstruction(MI);
646 // Include the auto-generated portion of the assembly writer.
647 #include "X86GenAsmWriter.inc"