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 shouldPrintGOT(TargetMachine &TM, const X86Subtarget* ST) {
201 return ST->isPICStyleGOT() && TM.getRelocationModel() == Reloc::PIC_;
204 static inline bool shouldPrintPLT(TargetMachine &TM, const X86Subtarget* ST) {
205 return ST->isTargetELF() && TM.getRelocationModel() == Reloc::PIC_ &&
206 (ST->isPICStyleRIPRel() || ST->isPICStyleGOT());
209 static inline bool shouldPrintStub(TargetMachine &TM, const X86Subtarget* ST) {
210 return ST->isPICStyleStub() && TM.getRelocationModel() != Reloc::Static;
213 void X86ATTAsmPrinter::printOperand(const MachineInstr *MI, unsigned OpNo,
214 const char *Modifier, bool NotRIPRel) {
215 const MachineOperand &MO = MI->getOperand(OpNo);
216 switch (MO.getType()) {
217 case MachineOperand::MO_Register: {
218 assert(TargetRegisterInfo::isPhysicalRegister(MO.getReg()) &&
219 "Virtual registers should not make it this far!");
221 unsigned Reg = MO.getReg();
222 if (Modifier && strncmp(Modifier, "subreg", strlen("subreg")) == 0) {
223 MVT VT = (strcmp(Modifier+6,"64") == 0) ?
224 MVT::i64 : ((strcmp(Modifier+6, "32") == 0) ? MVT::i32 :
225 ((strcmp(Modifier+6,"16") == 0) ? MVT::i16 : MVT::i8));
226 Reg = getX86SubSuperRegister(Reg, VT);
228 for (const char *Name = TRI->getAsmName(Reg); *Name; ++Name)
229 O << (char)tolower(*Name);
233 case MachineOperand::MO_Immediate:
235 (strcmp(Modifier, "debug") && strcmp(Modifier, "mem")))
239 case MachineOperand::MO_MachineBasicBlock:
240 printBasicBlockLabel(MO.getMBB());
242 case MachineOperand::MO_JumpTableIndex: {
243 bool isMemOp = Modifier && !strcmp(Modifier, "mem");
244 if (!isMemOp) O << '$';
245 O << TAI->getPrivateGlobalPrefix() << "JTI" << getFunctionNumber() << "_"
248 if (TM.getRelocationModel() == Reloc::PIC_) {
249 if (Subtarget->isPICStyleStub())
250 O << "-\"" << TAI->getPrivateGlobalPrefix() << getFunctionNumber()
252 else if (Subtarget->isPICStyleGOT())
256 if (isMemOp && Subtarget->isPICStyleRIPRel() && !NotRIPRel)
260 case MachineOperand::MO_ConstantPoolIndex: {
261 bool isMemOp = Modifier && !strcmp(Modifier, "mem");
262 if (!isMemOp) O << '$';
263 O << TAI->getPrivateGlobalPrefix() << "CPI" << getFunctionNumber() << "_"
266 if (TM.getRelocationModel() == Reloc::PIC_) {
267 if (Subtarget->isPICStyleStub())
268 O << "-\"" << TAI->getPrivateGlobalPrefix() << getFunctionNumber()
270 else if (Subtarget->isPICStyleGOT())
274 int Offset = MO.getOffset();
280 if (isMemOp && Subtarget->isPICStyleRIPRel() && !NotRIPRel)
284 case MachineOperand::MO_GlobalAddress: {
285 bool isCallOp = Modifier && !strcmp(Modifier, "call");
286 bool isMemOp = Modifier && !strcmp(Modifier, "mem");
287 bool needCloseParen = false;
289 const GlobalValue *GV = MO.getGlobal();
290 const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV);
292 // If GV is an alias then use the aliasee for determining
294 if (const GlobalAlias *GA = dyn_cast<GlobalAlias>(GV))
295 GVar = dyn_cast_or_null<GlobalVariable>(GA->resolveAliasedGlobal());
298 bool isThreadLocal = GVar && GVar->isThreadLocal();
300 std::string Name = Mang->getValueName(GV);
301 X86SharedAsmPrinter::decorateName(Name, GV);
303 if (!isMemOp && !isCallOp)
305 else if (Name[0] == '$') {
306 // The name begins with a dollar-sign. In order to avoid having it look
307 // like an integer immediate to the assembler, enclose it in parens.
309 needCloseParen = true;
312 if (shouldPrintStub(TM, Subtarget)) {
313 // Link-once, declaration, or Weakly-linked global variables need
314 // non-lazily-resolved stubs
315 if (GV->isDeclaration() ||
316 GV->hasWeakLinkage() ||
317 GV->hasLinkOnceLinkage() ||
318 GV->hasCommonLinkage()) {
319 // Dynamically-resolved functions need a stub for the function.
320 if (isCallOp && isa<Function>(GV)) {
321 FnStubs.insert(Name);
322 printSuffixedName(Name, "$stub");
324 GVStubs.insert(Name);
325 printSuffixedName(Name, "$non_lazy_ptr");
328 if (GV->hasDLLImportLinkage())
333 if (!isCallOp && TM.getRelocationModel() == Reloc::PIC_)
334 O << '-' << getPICLabelString(getFunctionNumber(), TAI, Subtarget);
336 if (GV->hasDLLImportLinkage()) {
342 if (shouldPrintPLT(TM, Subtarget)) {
343 // Assemble call via PLT for externally visible symbols
344 if (!GV->hasHiddenVisibility() && !GV->hasProtectedVisibility() &&
345 !GV->hasInternalLinkage())
348 if (Subtarget->isTargetCygMing() && GV->isDeclaration())
349 // Save function name for later type emission
350 FnStubs.insert(Name);
354 if (GV->hasExternalWeakLinkage())
355 ExtWeakSymbols.insert(GV);
357 int Offset = MO.getOffset();
364 if (TM.getRelocationModel() == Reloc::PIC_ || Subtarget->is64Bit())
365 O << "@TLSGD"; // general dynamic TLS model
367 if (GV->isDeclaration())
368 O << "@INDNTPOFF"; // initial exec TLS model
370 O << "@NTPOFF"; // local exec TLS model
371 } else if (isMemOp) {
372 if (shouldPrintGOT(TM, Subtarget)) {
373 if (Subtarget->GVRequiresExtraLoad(GV, TM, false))
377 } else if (Subtarget->isPICStyleRIPRel() && !NotRIPRel &&
378 TM.getRelocationModel() != Reloc::Static) {
379 if (Subtarget->GVRequiresExtraLoad(GV, TM, false))
382 if (needCloseParen) {
383 needCloseParen = false;
387 // Use rip when possible to reduce code size, except when
388 // index or base register are also part of the address. e.g.
389 // foo(%rip)(%rcx,%rax,4) is not legal
399 case MachineOperand::MO_ExternalSymbol: {
400 bool isCallOp = Modifier && !strcmp(Modifier, "call");
401 bool needCloseParen = false;
402 std::string Name(TAI->getGlobalPrefix());
403 Name += MO.getSymbolName();
404 if (isCallOp && shouldPrintStub(TM, Subtarget)) {
405 FnStubs.insert(Name);
406 printSuffixedName(Name, "$stub");
411 else if (Name[0] == '$') {
412 // The name begins with a dollar-sign. In order to avoid having it look
413 // like an integer immediate to the assembler, enclose it in parens.
415 needCloseParen = true;
420 if (shouldPrintPLT(TM, Subtarget)) {
421 std::string GOTName(TAI->getGlobalPrefix());
422 GOTName+="_GLOBAL_OFFSET_TABLE_";
424 // HACK! Emit extra offset to PC during printing GOT offset to
425 // compensate for the size of popl instruction. The resulting code
429 // popl %some_register
430 // addl $_GLOBAL_ADDRESS_TABLE_ + [.-piclabel], %some_register
432 << getPICLabelString(getFunctionNumber(), TAI, Subtarget) << "]";
441 if (!isCallOp && Subtarget->isPICStyleRIPRel())
447 O << "<unknown operand type>"; return;
451 void X86ATTAsmPrinter::printSSECC(const MachineInstr *MI, unsigned Op) {
452 unsigned char value = MI->getOperand(Op).getImm();
453 assert(value <= 7 && "Invalid ssecc argument!");
455 case 0: O << "eq"; break;
456 case 1: O << "lt"; break;
457 case 2: O << "le"; break;
458 case 3: O << "unord"; break;
459 case 4: O << "neq"; break;
460 case 5: O << "nlt"; break;
461 case 6: O << "nle"; break;
462 case 7: O << "ord"; break;
466 void X86ATTAsmPrinter::printMemReference(const MachineInstr *MI, unsigned Op,
467 const char *Modifier){
468 assert(isMem(MI, Op) && "Invalid memory reference!");
469 MachineOperand BaseReg = MI->getOperand(Op);
470 MachineOperand IndexReg = MI->getOperand(Op+2);
471 const MachineOperand &DispSpec = MI->getOperand(Op+3);
473 bool NotRIPRel = IndexReg.getReg() || BaseReg.getReg();
474 if (DispSpec.isGlobalAddress() ||
475 DispSpec.isConstantPoolIndex() ||
476 DispSpec.isJumpTableIndex()) {
477 printOperand(MI, Op+3, "mem", NotRIPRel);
479 int DispVal = DispSpec.getImm();
480 if (DispVal || (!IndexReg.getReg() && !BaseReg.getReg()))
484 if (IndexReg.getReg() || BaseReg.getReg()) {
485 unsigned ScaleVal = MI->getOperand(Op+1).getImm();
486 unsigned BaseRegOperand = 0, IndexRegOperand = 2;
488 // There are cases where we can end up with ESP/RSP in the indexreg slot.
489 // If this happens, swap the base/index register to support assemblers that
490 // don't work when the index is *SP.
491 if (IndexReg.getReg() == X86::ESP || IndexReg.getReg() == X86::RSP) {
492 assert(ScaleVal == 1 && "Scale not supported for stack pointer!");
493 std::swap(BaseReg, IndexReg);
494 std::swap(BaseRegOperand, IndexRegOperand);
498 if (BaseReg.getReg())
499 printOperand(MI, Op+BaseRegOperand, Modifier);
501 if (IndexReg.getReg()) {
503 printOperand(MI, Op+IndexRegOperand, Modifier);
505 O << "," << ScaleVal;
511 void X86ATTAsmPrinter::printPICJumpTableSetLabel(unsigned uid,
512 const MachineBasicBlock *MBB) const {
513 if (!TAI->getSetDirective())
516 // We don't need .set machinery if we have GOT-style relocations
517 if (Subtarget->isPICStyleGOT())
520 O << TAI->getSetDirective() << ' ' << TAI->getPrivateGlobalPrefix()
521 << getFunctionNumber() << '_' << uid << "_set_" << MBB->getNumber() << ',';
522 printBasicBlockLabel(MBB, false, false, false);
523 if (Subtarget->isPICStyleRIPRel())
524 O << '-' << TAI->getPrivateGlobalPrefix() << "JTI" << getFunctionNumber()
525 << '_' << uid << '\n';
527 O << '-' << getPICLabelString(getFunctionNumber(), TAI, Subtarget) << '\n';
530 void X86ATTAsmPrinter::printPICLabel(const MachineInstr *MI, unsigned Op) {
531 std::string label = getPICLabelString(getFunctionNumber(), TAI, Subtarget);
532 O << label << "\n" << label << ":";
536 void X86ATTAsmPrinter::printPICJumpTableEntry(const MachineJumpTableInfo *MJTI,
537 const MachineBasicBlock *MBB,
540 const char *JTEntryDirective = MJTI->getEntrySize() == 4 ?
541 TAI->getData32bitsDirective() : TAI->getData64bitsDirective();
543 O << JTEntryDirective << ' ';
545 if (TM.getRelocationModel() == Reloc::PIC_) {
546 if (Subtarget->isPICStyleRIPRel() || Subtarget->isPICStyleStub()) {
547 O << TAI->getPrivateGlobalPrefix() << getFunctionNumber()
548 << '_' << uid << "_set_" << MBB->getNumber();
549 } else if (Subtarget->isPICStyleGOT()) {
550 printBasicBlockLabel(MBB, false, false, false);
553 assert(0 && "Don't know how to print MBB label for this PIC mode");
555 printBasicBlockLabel(MBB, false, false, false);
558 bool X86ATTAsmPrinter::printAsmMRegister(const MachineOperand &MO,
560 unsigned Reg = MO.getReg();
562 default: return true; // Unknown mode.
563 case 'b': // Print QImode register
564 Reg = getX86SubSuperRegister(Reg, MVT::i8);
566 case 'h': // Print QImode high register
567 Reg = getX86SubSuperRegister(Reg, MVT::i8, true);
569 case 'w': // Print HImode register
570 Reg = getX86SubSuperRegister(Reg, MVT::i16);
572 case 'k': // Print SImode register
573 Reg = getX86SubSuperRegister(Reg, MVT::i32);
575 case 'q': // Print DImode register
576 Reg = getX86SubSuperRegister(Reg, MVT::i64);
581 for (const char *Name = TRI->getAsmName(Reg); *Name; ++Name)
582 O << (char)tolower(*Name);
586 /// PrintAsmOperand - Print out an operand for an inline asm expression.
588 bool X86ATTAsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
590 const char *ExtraCode) {
591 // Does this asm operand have a single letter operand modifier?
592 if (ExtraCode && ExtraCode[0]) {
593 if (ExtraCode[1] != 0) return true; // Unknown modifier.
595 switch (ExtraCode[0]) {
596 default: return true; // Unknown modifier.
597 case 'c': // Don't print "$" before a global var name or constant.
598 printOperand(MI, OpNo, "mem");
600 case 'b': // Print QImode register
601 case 'h': // Print QImode high register
602 case 'w': // Print HImode register
603 case 'k': // Print SImode register
604 case 'q': // Print DImode register
605 if (MI->getOperand(OpNo).isRegister())
606 return printAsmMRegister(MI->getOperand(OpNo), ExtraCode[0]);
607 printOperand(MI, OpNo);
610 case 'P': // Don't print @PLT, but do print as memory.
611 printOperand(MI, OpNo, "mem");
616 printOperand(MI, OpNo);
620 bool X86ATTAsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI,
623 const char *ExtraCode) {
624 if (ExtraCode && ExtraCode[0]) {
625 if (ExtraCode[1] != 0) return true; // Unknown modifier.
627 switch (ExtraCode[0]) {
628 default: return true; // Unknown modifier.
629 case 'b': // Print QImode register
630 case 'h': // Print QImode high register
631 case 'w': // Print HImode register
632 case 'k': // Print SImode register
633 case 'q': // Print SImode register
634 // These only apply to registers, ignore on mem.
638 printMemReference(MI, OpNo);
642 /// printMachineInstruction -- Print out a single X86 LLVM instruction
643 /// MI in AT&T syntax to the current output stream.
645 void X86ATTAsmPrinter::printMachineInstruction(const MachineInstr *MI) {
648 // Call the autogenerated instruction printer routines.
649 printInstruction(MI);
652 // Include the auto-generated portion of the assembly writer.
653 #include "X86GenAsmWriter.inc"