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.
104 if (Subtarget->isTargetDarwin())
105 // FIXME: This should be parameterized somewhere.
106 EmitAlignment(4, F, 0, true, 0x90);
110 case Function::DLLExportLinkage:
111 DLLExportedFns.insert(Mang->makeNameProper(F->getName(), ""));
113 case Function::ExternalLinkage:
114 if (Subtarget->isTargetDarwin())
115 // FIXME: This should be parameterized somewhere.
116 EmitAlignment(4, F, 0, true, 0x90);
119 O << "\t.globl\t" << CurrentFnName << "\n";
121 case Function::LinkOnceLinkage:
122 case Function::WeakLinkage:
123 if (Subtarget->isTargetDarwin()) {
124 // FIXME: This should be parameterized somewhere.
125 EmitAlignment(4, F, 0, true, 0x90);
126 O << "\t.globl\t" << CurrentFnName << "\n";
127 O << TAI->getWeakDefDirective() << CurrentFnName << "\n";
128 } else if (Subtarget->isTargetCygMing()) {
130 O << "\t.globl\t" << CurrentFnName << "\n";
131 O << "\t.linkonce discard\n";
134 O << "\t.weak\t" << CurrentFnName << "\n";
138 if (F->hasHiddenVisibility()) {
139 if (const char *Directive = TAI->getHiddenDirective())
140 O << Directive << CurrentFnName << "\n";
141 } else if (F->hasProtectedVisibility()) {
142 if (const char *Directive = TAI->getProtectedDirective())
143 O << Directive << CurrentFnName << "\n";
146 if (Subtarget->isTargetELF())
147 O << "\t.type\t" << CurrentFnName << ",@function\n";
148 else if (Subtarget->isTargetCygMing()) {
149 O << "\t.def\t " << CurrentFnName
151 (F->getLinkage() == Function::InternalLinkage ? COFF::C_STAT : COFF::C_EXT)
152 << ";\t.type\t" << (COFF::DT_FCN << COFF::N_BTSHFT)
156 O << CurrentFnName << ":\n";
157 // Add some workaround for linkonce linkage on Cygwin\MinGW
158 if (Subtarget->isTargetCygMing() &&
159 (F->getLinkage() == Function::LinkOnceLinkage ||
160 F->getLinkage() == Function::WeakLinkage))
161 O << "Lllvm$workaround$fake$stub$" << CurrentFnName << ":\n";
163 if (TAI->doesSupportDebugInformation()) {
164 // Emit pre-function debug information.
165 DW.BeginFunction(&MF);
168 if (Subtarget->isTargetDarwin()) {
169 // If the function is empty, then we need to emit *something*. Otherwise,
170 // the function's label might be associated with something that it wasn't
171 // meant to be associated with. We emit a noop in this situation.
172 MachineFunction::iterator I = MF.begin();
174 if (++I == MF.end() && MF.front().empty())
178 // Print out code for the function.
179 for (MachineFunction::const_iterator I = MF.begin(), E = MF.end();
181 // Print a label for the basic block.
182 if (!I->pred_empty()) {
183 printBasicBlockLabel(I, true);
186 for (MachineBasicBlock::const_iterator II = I->begin(), IE = I->end();
188 // Print the assembly for the instruction.
189 printMachineInstruction(II);
193 if (TAI->hasDotTypeDotSizeDirective())
194 O << "\t.size\t" << CurrentFnName << ", .-" << CurrentFnName << "\n";
196 if (TAI->doesSupportDebugInformation()) {
197 // Emit post-function debug information.
201 // Print out jump tables referenced by the function.
202 EmitJumpTableInfo(MF.getJumpTableInfo(), MF);
204 // We didn't modify anything.
208 static inline bool printGOT(TargetMachine &TM, const X86Subtarget* ST) {
209 return ST->isPICStyleGOT() && TM.getRelocationModel() == Reloc::PIC_;
212 static inline bool printStub(TargetMachine &TM, const X86Subtarget* ST) {
213 return ST->isPICStyleStub() && TM.getRelocationModel() != Reloc::Static;
216 void X86ATTAsmPrinter::printOperand(const MachineInstr *MI, unsigned OpNo,
217 const char *Modifier, bool NotRIPRel) {
218 const MachineOperand &MO = MI->getOperand(OpNo);
219 const TargetRegisterInfo &RI = *TM.getRegisterInfo();
220 switch (MO.getType()) {
221 case MachineOperand::MO_Register: {
222 assert(TargetRegisterInfo::isPhysicalRegister(MO.getReg()) &&
223 "Virtual registers should not make it this far!");
225 unsigned Reg = MO.getReg();
226 if (Modifier && strncmp(Modifier, "subreg", strlen("subreg")) == 0) {
227 MVT::ValueType VT = (strcmp(Modifier+6,"64") == 0) ?
228 MVT::i64 : ((strcmp(Modifier+6, "32") == 0) ? MVT::i32 :
229 ((strcmp(Modifier+6,"16") == 0) ? MVT::i16 : MVT::i8));
230 Reg = getX86SubSuperRegister(Reg, VT);
232 for (const char *Name = RI.get(Reg).Name; *Name; ++Name)
233 O << (char)tolower(*Name);
237 case MachineOperand::MO_Immediate:
239 (strcmp(Modifier, "debug") && strcmp(Modifier, "mem")))
243 case MachineOperand::MO_MachineBasicBlock:
244 printBasicBlockLabel(MO.getMBB());
246 case MachineOperand::MO_JumpTableIndex: {
247 bool isMemOp = Modifier && !strcmp(Modifier, "mem");
248 if (!isMemOp) O << '$';
249 O << TAI->getPrivateGlobalPrefix() << "JTI" << getFunctionNumber() << "_"
252 if (TM.getRelocationModel() == Reloc::PIC_) {
253 if (Subtarget->isPICStyleStub())
254 O << "-\"" << TAI->getPrivateGlobalPrefix() << getFunctionNumber()
256 else if (Subtarget->isPICStyleGOT())
260 if (isMemOp && Subtarget->isPICStyleRIPRel() && !NotRIPRel)
264 case MachineOperand::MO_ConstantPoolIndex: {
265 bool isMemOp = Modifier && !strcmp(Modifier, "mem");
266 if (!isMemOp) O << '$';
267 O << TAI->getPrivateGlobalPrefix() << "CPI" << getFunctionNumber() << "_"
270 if (TM.getRelocationModel() == Reloc::PIC_) {
271 if (Subtarget->isPICStyleStub())
272 O << "-\"" << TAI->getPrivateGlobalPrefix() << getFunctionNumber()
274 else if (Subtarget->isPICStyleGOT())
278 int Offset = MO.getOffset();
284 if (isMemOp && Subtarget->isPICStyleRIPRel() && !NotRIPRel)
288 case MachineOperand::MO_GlobalAddress: {
289 bool isCallOp = Modifier && !strcmp(Modifier, "call");
290 bool isMemOp = Modifier && !strcmp(Modifier, "mem");
291 bool needCloseParen = false;
293 GlobalValue *GV = MO.getGlobal();
294 GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV);
295 bool isThreadLocal = GVar && GVar->isThreadLocal();
297 std::string Name = Mang->getValueName(GV);
298 X86SharedAsmPrinter::decorateName(Name, GV);
300 if (!isMemOp && !isCallOp)
302 else if (Name[0] == '$') {
303 // The name begins with a dollar-sign. In order to avoid having it look
304 // like an integer immediate to the assembler, enclose it in parens.
306 needCloseParen = true;
309 if (printStub(TM, Subtarget)) {
310 // Link-once, declaration, or Weakly-linked global variables need
311 // non-lazily-resolved stubs
312 if (GV->isDeclaration() ||
313 GV->hasWeakLinkage() ||
314 GV->hasLinkOnceLinkage()) {
315 // Dynamically-resolved functions need a stub for the function.
316 if (isCallOp && isa<Function>(GV)) {
317 FnStubs.insert(Name);
318 O << TAI->getPrivateGlobalPrefix() << Name << "$stub";
320 GVStubs.insert(Name);
321 O << TAI->getPrivateGlobalPrefix() << Name << "$non_lazy_ptr";
324 if (GV->hasDLLImportLinkage())
329 if (!isCallOp && TM.getRelocationModel() == Reloc::PIC_)
330 O << '-' << getPICLabelString(getFunctionNumber(), TAI, Subtarget);
332 if (GV->hasDLLImportLinkage()) {
337 if (isCallOp && isa<Function>(GV)) {
338 if (printGOT(TM, Subtarget)) {
339 // Assemble call via PLT for non-local symbols
340 if (!(GV->hasHiddenVisibility() || GV->hasProtectedVisibility()) ||
344 if (Subtarget->isTargetCygMing() && GV->isDeclaration())
345 // Save function name for later type emission
346 FnStubs.insert(Name);
350 if (GV->hasExternalWeakLinkage())
351 ExtWeakSymbols.insert(GV);
353 int Offset = MO.getOffset();
360 if (TM.getRelocationModel() == Reloc::PIC_)
361 O << "@TLSGD"; // general dynamic TLS model
363 if (GV->isDeclaration())
364 O << "@INDNTPOFF"; // initial exec TLS model
366 O << "@NTPOFF"; // local exec TLS model
367 } else if (isMemOp) {
368 if (printGOT(TM, Subtarget)) {
369 if (Subtarget->GVRequiresExtraLoad(GV, TM, false))
373 } else if (Subtarget->isPICStyleRIPRel() && !NotRIPRel &&
374 TM.getRelocationModel() != Reloc::Static) {
375 if (Subtarget->GVRequiresExtraLoad(GV, TM, false))
378 if (needCloseParen) {
379 needCloseParen = false;
383 // Use rip when possible to reduce code size, except when
384 // index or base register are also part of the address. e.g.
385 // foo(%rip)(%rcx,%rax,4) is not legal
395 case MachineOperand::MO_ExternalSymbol: {
396 bool isCallOp = Modifier && !strcmp(Modifier, "call");
397 bool needCloseParen = false;
398 std::string Name(TAI->getGlobalPrefix());
399 Name += MO.getSymbolName();
400 if (isCallOp && printStub(TM, Subtarget)) {
401 FnStubs.insert(Name);
402 O << TAI->getPrivateGlobalPrefix() << Name << "$stub";
407 else if (Name[0] == '$') {
408 // The name begins with a dollar-sign. In order to avoid having it look
409 // like an integer immediate to the assembler, enclose it in parens.
411 needCloseParen = true;
416 if (printGOT(TM, Subtarget)) {
417 std::string GOTName(TAI->getGlobalPrefix());
418 GOTName+="_GLOBAL_OFFSET_TABLE_";
420 // HACK! Emit extra offset to PC during printing GOT offset to
421 // compensate for the size of popl instruction. The resulting code
425 // popl %some_register
426 // addl $_GLOBAL_ADDRESS_TABLE_ + [.-piclabel], %some_register
428 << getPICLabelString(getFunctionNumber(), TAI, Subtarget) << "]";
437 if (!isCallOp && Subtarget->isPICStyleRIPRel())
443 O << "<unknown operand type>"; return;
447 void X86ATTAsmPrinter::printSSECC(const MachineInstr *MI, unsigned Op) {
448 unsigned char value = MI->getOperand(Op).getImm();
449 assert(value <= 7 && "Invalid ssecc argument!");
451 case 0: O << "eq"; break;
452 case 1: O << "lt"; break;
453 case 2: O << "le"; break;
454 case 3: O << "unord"; break;
455 case 4: O << "neq"; break;
456 case 5: O << "nlt"; break;
457 case 6: O << "nle"; break;
458 case 7: O << "ord"; break;
462 void X86ATTAsmPrinter::printMemReference(const MachineInstr *MI, unsigned Op,
463 const char *Modifier){
464 assert(isMem(MI, Op) && "Invalid memory reference!");
465 MachineOperand BaseReg = MI->getOperand(Op);
466 MachineOperand IndexReg = MI->getOperand(Op+2);
467 const MachineOperand &DispSpec = MI->getOperand(Op+3);
469 bool NotRIPRel = IndexReg.getReg() || BaseReg.getReg();
470 if (DispSpec.isGlobalAddress() ||
471 DispSpec.isConstantPoolIndex() ||
472 DispSpec.isJumpTableIndex()) {
473 printOperand(MI, Op+3, "mem", NotRIPRel);
475 int DispVal = DispSpec.getImm();
476 if (DispVal || (!IndexReg.getReg() && !BaseReg.getReg()))
480 if (IndexReg.getReg() || BaseReg.getReg()) {
481 unsigned ScaleVal = MI->getOperand(Op+1).getImm();
482 unsigned BaseRegOperand = 0, IndexRegOperand = 2;
484 // There are cases where we can end up with ESP/RSP in the indexreg slot.
485 // If this happens, swap the base/index register to support assemblers that
486 // don't work when the index is *SP.
487 if (IndexReg.getReg() == X86::ESP || IndexReg.getReg() == X86::RSP) {
488 assert(ScaleVal == 1 && "Scale not supported for stack pointer!");
489 std::swap(BaseReg, IndexReg);
490 std::swap(BaseRegOperand, IndexRegOperand);
494 if (BaseReg.getReg())
495 printOperand(MI, Op+BaseRegOperand, Modifier);
497 if (IndexReg.getReg()) {
499 printOperand(MI, Op+IndexRegOperand, Modifier);
501 O << "," << ScaleVal;
507 void X86ATTAsmPrinter::printPICJumpTableSetLabel(unsigned uid,
508 const MachineBasicBlock *MBB) const {
509 if (!TAI->getSetDirective())
512 // We don't need .set machinery if we have GOT-style relocations
513 if (Subtarget->isPICStyleGOT())
516 O << TAI->getSetDirective() << ' ' << TAI->getPrivateGlobalPrefix()
517 << getFunctionNumber() << '_' << uid << "_set_" << MBB->getNumber() << ',';
518 printBasicBlockLabel(MBB, false, false);
519 if (Subtarget->isPICStyleRIPRel())
520 O << '-' << TAI->getPrivateGlobalPrefix() << "JTI" << getFunctionNumber()
521 << '_' << uid << '\n';
523 O << '-' << getPICLabelString(getFunctionNumber(), TAI, Subtarget) << '\n';
526 void X86ATTAsmPrinter::printPICLabel(const MachineInstr *MI, unsigned Op) {
527 std::string label = getPICLabelString(getFunctionNumber(), TAI, Subtarget);
528 O << label << "\n" << label << ":";
532 void X86ATTAsmPrinter::printPICJumpTableEntry(const MachineJumpTableInfo *MJTI,
533 const MachineBasicBlock *MBB,
536 const char *JTEntryDirective = MJTI->getEntrySize() == 4 ?
537 TAI->getData32bitsDirective() : TAI->getData64bitsDirective();
539 O << JTEntryDirective << ' ';
541 if (TM.getRelocationModel() == Reloc::PIC_) {
542 if (Subtarget->isPICStyleRIPRel() || Subtarget->isPICStyleStub()) {
543 O << TAI->getPrivateGlobalPrefix() << getFunctionNumber()
544 << '_' << uid << "_set_" << MBB->getNumber();
545 } else if (Subtarget->isPICStyleGOT()) {
546 printBasicBlockLabel(MBB, false, false);
549 assert(0 && "Don't know how to print MBB label for this PIC mode");
551 printBasicBlockLabel(MBB, false, false);
554 bool X86ATTAsmPrinter::printAsmMRegister(const MachineOperand &MO,
556 const TargetRegisterInfo &RI = *TM.getRegisterInfo();
557 unsigned Reg = MO.getReg();
559 default: return true; // Unknown mode.
560 case 'b': // Print QImode register
561 Reg = getX86SubSuperRegister(Reg, MVT::i8);
563 case 'h': // Print QImode high register
564 Reg = getX86SubSuperRegister(Reg, MVT::i8, true);
566 case 'w': // Print HImode register
567 Reg = getX86SubSuperRegister(Reg, MVT::i16);
569 case 'k': // Print SImode register
570 Reg = getX86SubSuperRegister(Reg, MVT::i32);
572 case 'q': // Print DImode register
573 Reg = getX86SubSuperRegister(Reg, MVT::i64);
578 for (const char *Name = RI.get(Reg).Name; *Name; ++Name)
579 O << (char)tolower(*Name);
583 /// PrintAsmOperand - Print out an operand for an inline asm expression.
585 bool X86ATTAsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
587 const char *ExtraCode) {
588 // Does this asm operand have a single letter operand modifier?
589 if (ExtraCode && ExtraCode[0]) {
590 if (ExtraCode[1] != 0) return true; // Unknown modifier.
592 switch (ExtraCode[0]) {
593 default: return true; // Unknown modifier.
594 case 'c': // Don't print "$" before a global var name or constant.
595 printOperand(MI, OpNo, "mem");
597 case 'b': // Print QImode register
598 case 'h': // Print QImode high register
599 case 'w': // Print HImode register
600 case 'k': // Print SImode register
601 case 'q': // Print DImode register
602 if (MI->getOperand(OpNo).isRegister())
603 return printAsmMRegister(MI->getOperand(OpNo), ExtraCode[0]);
604 printOperand(MI, OpNo);
607 case 'P': // Don't print @PLT, but do print as memory.
608 printOperand(MI, OpNo, "mem");
613 printOperand(MI, OpNo);
617 bool X86ATTAsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI,
620 const char *ExtraCode) {
621 if (ExtraCode && ExtraCode[0]) {
622 if (ExtraCode[1] != 0) return true; // Unknown modifier.
624 switch (ExtraCode[0]) {
625 default: return true; // Unknown modifier.
626 case 'b': // Print QImode register
627 case 'h': // Print QImode high register
628 case 'w': // Print HImode register
629 case 'k': // Print SImode register
630 case 'q': // Print SImode register
631 // These only apply to registers, ignore on mem.
635 printMemReference(MI, OpNo);
639 /// printMachineInstruction -- Print out a single X86 LLVM instruction
640 /// MI in AT&T syntax to the current output stream.
642 void X86ATTAsmPrinter::printMachineInstruction(const MachineInstr *MI) {
645 // See if a truncate instruction can be turned into a nop.
646 switch (MI->getOpcode()) {
648 case X86::PsMOVZX64rr32:
649 O << TAI->getCommentString() << " ZERO-EXTEND " << "\n\t";
653 // Call the autogenerated instruction printer routines.
654 printInstruction(MI);
657 // Include the auto-generated portion of the assembly writer.
658 #include "X86GenAsmWriter.inc"