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 switch (MO.getType()) {
209 case MachineOperand::MO_Register: {
210 assert(TargetRegisterInfo::isPhysicalRegister(MO.getReg()) &&
211 "Virtual registers should not make it this far!");
213 unsigned Reg = MO.getReg();
214 if (Modifier && strncmp(Modifier, "subreg", strlen("subreg")) == 0) {
215 MVT::ValueType VT = (strcmp(Modifier+6,"64") == 0) ?
216 MVT::i64 : ((strcmp(Modifier+6, "32") == 0) ? MVT::i32 :
217 ((strcmp(Modifier+6,"16") == 0) ? MVT::i16 : MVT::i8));
218 Reg = getX86SubSuperRegister(Reg, VT);
220 for (const char *Name = TRI->getAsmName(Reg); *Name; ++Name)
221 O << (char)tolower(*Name);
225 case MachineOperand::MO_Immediate:
227 (strcmp(Modifier, "debug") && strcmp(Modifier, "mem")))
231 case MachineOperand::MO_MachineBasicBlock:
232 printBasicBlockLabel(MO.getMBB());
234 case MachineOperand::MO_JumpTableIndex: {
235 bool isMemOp = Modifier && !strcmp(Modifier, "mem");
236 if (!isMemOp) O << '$';
237 O << TAI->getPrivateGlobalPrefix() << "JTI" << getFunctionNumber() << "_"
240 if (TM.getRelocationModel() == Reloc::PIC_) {
241 if (Subtarget->isPICStyleStub())
242 O << "-\"" << TAI->getPrivateGlobalPrefix() << getFunctionNumber()
244 else if (Subtarget->isPICStyleGOT())
248 if (isMemOp && Subtarget->isPICStyleRIPRel() && !NotRIPRel)
252 case MachineOperand::MO_ConstantPoolIndex: {
253 bool isMemOp = Modifier && !strcmp(Modifier, "mem");
254 if (!isMemOp) O << '$';
255 O << TAI->getPrivateGlobalPrefix() << "CPI" << getFunctionNumber() << "_"
258 if (TM.getRelocationModel() == Reloc::PIC_) {
259 if (Subtarget->isPICStyleStub())
260 O << "-\"" << TAI->getPrivateGlobalPrefix() << getFunctionNumber()
262 else if (Subtarget->isPICStyleGOT())
266 int Offset = MO.getOffset();
272 if (isMemOp && Subtarget->isPICStyleRIPRel() && !NotRIPRel)
276 case MachineOperand::MO_GlobalAddress: {
277 bool isCallOp = Modifier && !strcmp(Modifier, "call");
278 bool isMemOp = Modifier && !strcmp(Modifier, "mem");
279 bool needCloseParen = false;
281 const GlobalValue *GV = MO.getGlobal();
282 const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV);
284 // If GV is an alias then use the aliasee for determining
286 if (const GlobalAlias *GA = dyn_cast<GlobalAlias>(GV))
287 GVar = dyn_cast_or_null<GlobalVariable>(GA->resolveAliasedGlobal());
290 bool isThreadLocal = GVar && GVar->isThreadLocal();
292 std::string Name = Mang->getValueName(GV);
293 X86SharedAsmPrinter::decorateName(Name, GV);
295 if (!isMemOp && !isCallOp)
297 else if (Name[0] == '$') {
298 // The name begins with a dollar-sign. In order to avoid having it look
299 // like an integer immediate to the assembler, enclose it in parens.
301 needCloseParen = true;
304 if (printStub(TM, Subtarget)) {
305 // Link-once, declaration, or Weakly-linked global variables need
306 // non-lazily-resolved stubs
307 if (GV->isDeclaration() ||
308 GV->hasWeakLinkage() ||
309 GV->hasLinkOnceLinkage()) {
310 // Dynamically-resolved functions need a stub for the function.
311 if (isCallOp && isa<Function>(GV)) {
312 FnStubs.insert(Name);
313 O << TAI->getPrivateGlobalPrefix() << Name << "$stub";
315 GVStubs.insert(Name);
316 O << TAI->getPrivateGlobalPrefix() << Name << "$non_lazy_ptr";
319 if (GV->hasDLLImportLinkage())
324 if (!isCallOp && TM.getRelocationModel() == Reloc::PIC_)
325 O << '-' << getPICLabelString(getFunctionNumber(), TAI, Subtarget);
327 if (GV->hasDLLImportLinkage()) {
332 if (isCallOp && isa<Function>(GV)) {
333 if (printGOT(TM, Subtarget)) {
334 // Assemble call via PLT for non-local symbols
335 if (!(GV->hasHiddenVisibility() || GV->hasProtectedVisibility()) ||
339 if (Subtarget->isTargetCygMing() && GV->isDeclaration())
340 // Save function name for later type emission
341 FnStubs.insert(Name);
345 if (GV->hasExternalWeakLinkage())
346 ExtWeakSymbols.insert(GV);
348 int Offset = MO.getOffset();
355 if (TM.getRelocationModel() == Reloc::PIC_)
356 O << "@TLSGD"; // general dynamic TLS model
358 if (GV->isDeclaration())
359 O << "@INDNTPOFF"; // initial exec TLS model
361 O << "@NTPOFF"; // local exec TLS model
362 } else if (isMemOp) {
363 if (printGOT(TM, Subtarget)) {
364 if (Subtarget->GVRequiresExtraLoad(GV, TM, false))
368 } else if (Subtarget->isPICStyleRIPRel() && !NotRIPRel &&
369 TM.getRelocationModel() != Reloc::Static) {
370 if (Subtarget->GVRequiresExtraLoad(GV, TM, false))
373 if (needCloseParen) {
374 needCloseParen = false;
378 // Use rip when possible to reduce code size, except when
379 // index or base register are also part of the address. e.g.
380 // foo(%rip)(%rcx,%rax,4) is not legal
390 case MachineOperand::MO_ExternalSymbol: {
391 bool isCallOp = Modifier && !strcmp(Modifier, "call");
392 bool needCloseParen = false;
393 std::string Name(TAI->getGlobalPrefix());
394 Name += MO.getSymbolName();
395 if (isCallOp && printStub(TM, Subtarget)) {
396 FnStubs.insert(Name);
397 O << TAI->getPrivateGlobalPrefix() << Name << "$stub";
402 else if (Name[0] == '$') {
403 // The name begins with a dollar-sign. In order to avoid having it look
404 // like an integer immediate to the assembler, enclose it in parens.
406 needCloseParen = true;
411 if (printGOT(TM, Subtarget)) {
412 std::string GOTName(TAI->getGlobalPrefix());
413 GOTName+="_GLOBAL_OFFSET_TABLE_";
415 // HACK! Emit extra offset to PC during printing GOT offset to
416 // compensate for the size of popl instruction. The resulting code
420 // popl %some_register
421 // addl $_GLOBAL_ADDRESS_TABLE_ + [.-piclabel], %some_register
423 << getPICLabelString(getFunctionNumber(), TAI, Subtarget) << "]";
432 if (!isCallOp && Subtarget->isPICStyleRIPRel())
438 O << "<unknown operand type>"; return;
442 void X86ATTAsmPrinter::printSSECC(const MachineInstr *MI, unsigned Op) {
443 unsigned char value = MI->getOperand(Op).getImm();
444 assert(value <= 7 && "Invalid ssecc argument!");
446 case 0: O << "eq"; break;
447 case 1: O << "lt"; break;
448 case 2: O << "le"; break;
449 case 3: O << "unord"; break;
450 case 4: O << "neq"; break;
451 case 5: O << "nlt"; break;
452 case 6: O << "nle"; break;
453 case 7: O << "ord"; break;
457 void X86ATTAsmPrinter::printMemReference(const MachineInstr *MI, unsigned Op,
458 const char *Modifier){
459 assert(isMem(MI, Op) && "Invalid memory reference!");
460 MachineOperand BaseReg = MI->getOperand(Op);
461 MachineOperand IndexReg = MI->getOperand(Op+2);
462 const MachineOperand &DispSpec = MI->getOperand(Op+3);
464 bool NotRIPRel = IndexReg.getReg() || BaseReg.getReg();
465 if (DispSpec.isGlobalAddress() ||
466 DispSpec.isConstantPoolIndex() ||
467 DispSpec.isJumpTableIndex()) {
468 printOperand(MI, Op+3, "mem", NotRIPRel);
470 int DispVal = DispSpec.getImm();
471 if (DispVal || (!IndexReg.getReg() && !BaseReg.getReg()))
475 if (IndexReg.getReg() || BaseReg.getReg()) {
476 unsigned ScaleVal = MI->getOperand(Op+1).getImm();
477 unsigned BaseRegOperand = 0, IndexRegOperand = 2;
479 // There are cases where we can end up with ESP/RSP in the indexreg slot.
480 // If this happens, swap the base/index register to support assemblers that
481 // don't work when the index is *SP.
482 if (IndexReg.getReg() == X86::ESP || IndexReg.getReg() == X86::RSP) {
483 assert(ScaleVal == 1 && "Scale not supported for stack pointer!");
484 std::swap(BaseReg, IndexReg);
485 std::swap(BaseRegOperand, IndexRegOperand);
489 if (BaseReg.getReg())
490 printOperand(MI, Op+BaseRegOperand, Modifier);
492 if (IndexReg.getReg()) {
494 printOperand(MI, Op+IndexRegOperand, Modifier);
496 O << "," << ScaleVal;
502 void X86ATTAsmPrinter::printPICJumpTableSetLabel(unsigned uid,
503 const MachineBasicBlock *MBB) const {
504 if (!TAI->getSetDirective())
507 // We don't need .set machinery if we have GOT-style relocations
508 if (Subtarget->isPICStyleGOT())
511 O << TAI->getSetDirective() << ' ' << TAI->getPrivateGlobalPrefix()
512 << getFunctionNumber() << '_' << uid << "_set_" << MBB->getNumber() << ',';
513 printBasicBlockLabel(MBB, false, false, false);
514 if (Subtarget->isPICStyleRIPRel())
515 O << '-' << TAI->getPrivateGlobalPrefix() << "JTI" << getFunctionNumber()
516 << '_' << uid << '\n';
518 O << '-' << getPICLabelString(getFunctionNumber(), TAI, Subtarget) << '\n';
521 void X86ATTAsmPrinter::printPICLabel(const MachineInstr *MI, unsigned Op) {
522 std::string label = getPICLabelString(getFunctionNumber(), TAI, Subtarget);
523 O << label << "\n" << label << ":";
527 void X86ATTAsmPrinter::printPICJumpTableEntry(const MachineJumpTableInfo *MJTI,
528 const MachineBasicBlock *MBB,
531 const char *JTEntryDirective = MJTI->getEntrySize() == 4 ?
532 TAI->getData32bitsDirective() : TAI->getData64bitsDirective();
534 O << JTEntryDirective << ' ';
536 if (TM.getRelocationModel() == Reloc::PIC_) {
537 if (Subtarget->isPICStyleRIPRel() || Subtarget->isPICStyleStub()) {
538 O << TAI->getPrivateGlobalPrefix() << getFunctionNumber()
539 << '_' << uid << "_set_" << MBB->getNumber();
540 } else if (Subtarget->isPICStyleGOT()) {
541 printBasicBlockLabel(MBB, false, false, false);
544 assert(0 && "Don't know how to print MBB label for this PIC mode");
546 printBasicBlockLabel(MBB, false, false, false);
549 bool X86ATTAsmPrinter::printAsmMRegister(const MachineOperand &MO,
551 unsigned Reg = MO.getReg();
553 default: return true; // Unknown mode.
554 case 'b': // Print QImode register
555 Reg = getX86SubSuperRegister(Reg, MVT::i8);
557 case 'h': // Print QImode high register
558 Reg = getX86SubSuperRegister(Reg, MVT::i8, true);
560 case 'w': // Print HImode register
561 Reg = getX86SubSuperRegister(Reg, MVT::i16);
563 case 'k': // Print SImode register
564 Reg = getX86SubSuperRegister(Reg, MVT::i32);
566 case 'q': // Print DImode register
567 Reg = getX86SubSuperRegister(Reg, MVT::i64);
572 for (const char *Name = TRI->getAsmName(Reg); *Name; ++Name)
573 O << (char)tolower(*Name);
577 /// PrintAsmOperand - Print out an operand for an inline asm expression.
579 bool X86ATTAsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
581 const char *ExtraCode) {
582 // Does this asm operand have a single letter operand modifier?
583 if (ExtraCode && ExtraCode[0]) {
584 if (ExtraCode[1] != 0) return true; // Unknown modifier.
586 switch (ExtraCode[0]) {
587 default: return true; // Unknown modifier.
588 case 'c': // Don't print "$" before a global var name or constant.
589 printOperand(MI, OpNo, "mem");
591 case 'b': // Print QImode register
592 case 'h': // Print QImode high register
593 case 'w': // Print HImode register
594 case 'k': // Print SImode register
595 case 'q': // Print DImode register
596 if (MI->getOperand(OpNo).isRegister())
597 return printAsmMRegister(MI->getOperand(OpNo), ExtraCode[0]);
598 printOperand(MI, OpNo);
601 case 'P': // Don't print @PLT, but do print as memory.
602 printOperand(MI, OpNo, "mem");
607 printOperand(MI, OpNo);
611 bool X86ATTAsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI,
614 const char *ExtraCode) {
615 if (ExtraCode && ExtraCode[0]) {
616 if (ExtraCode[1] != 0) return true; // Unknown modifier.
618 switch (ExtraCode[0]) {
619 default: return true; // Unknown modifier.
620 case 'b': // Print QImode register
621 case 'h': // Print QImode high register
622 case 'w': // Print HImode register
623 case 'k': // Print SImode register
624 case 'q': // Print SImode register
625 // These only apply to registers, ignore on mem.
629 printMemReference(MI, OpNo);
633 /// printMachineInstruction -- Print out a single X86 LLVM instruction
634 /// MI in AT&T syntax to the current output stream.
636 void X86ATTAsmPrinter::printMachineInstruction(const MachineInstr *MI) {
639 // Call the autogenerated instruction printer routines.
640 printInstruction(MI);
643 // Include the auto-generated portion of the assembly writer.
644 #include "X86GenAsmWriter.inc"