1 //===-- X86AsmPrinter.cpp - Convert X86 LLVM IR to X86 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 the shared super class printer that converts from our internal
11 // representation of machine-dependent LLVM code to Intel and AT&T format
13 // This printer is the output mechanism used by `llc'.
15 //===----------------------------------------------------------------------===//
17 #include "X86AsmPrinter.h"
18 #include "X86ATTAsmPrinter.h"
20 #include "X86IntelAsmPrinter.h"
21 #include "X86MachineFunctionInfo.h"
22 #include "X86Subtarget.h"
23 #include "llvm/ADT/StringExtras.h"
24 #include "llvm/CallingConv.h"
25 #include "llvm/Constants.h"
26 #include "llvm/Module.h"
27 #include "llvm/DerivedTypes.h"
28 #include "llvm/ParameterAttributes.h"
29 #include "llvm/Type.h"
30 #include "llvm/Assembly/Writer.h"
31 #include "llvm/Support/Mangler.h"
32 #include "llvm/Target/TargetAsmInfo.h"
33 #include "llvm/Target/TargetOptions.h"
36 static X86MachineFunctionInfo calculateFunctionInfo(const Function *F,
37 const TargetData *TD) {
38 X86MachineFunctionInfo Info;
41 switch (F->getCallingConv()) {
42 case CallingConv::X86_StdCall:
43 Info.setDecorationStyle(StdCall);
45 case CallingConv::X86_FastCall:
46 Info.setDecorationStyle(FastCall);
53 for (Function::const_arg_iterator AI = F->arg_begin(), AE = F->arg_end();
54 AI != AE; ++AI, ++argNum) {
55 const Type* Ty = AI->getType();
57 // 'Dereference' type in case of byval parameter attribute
58 if (F->paramHasAttr(argNum, ParamAttr::ByVal))
59 Ty = cast<PointerType>(Ty)->getElementType();
61 // Size should be aligned to DWORD boundary
62 Size += ((TD->getABITypeSize(Ty) + 3)/4)*4;
65 // We're not supporting tooooo huge arguments :)
66 Info.setBytesToPopOnReturn((unsigned int)Size);
71 /// decorateName - Query FunctionInfoMap and use this information for various
73 void X86SharedAsmPrinter::decorateName(std::string &Name,
74 const GlobalValue *GV) {
75 const Function *F = dyn_cast<Function>(GV);
78 // We don't want to decorate non-stdcall or non-fastcall functions right now
79 unsigned CC = F->getCallingConv();
80 if (CC != CallingConv::X86_StdCall && CC != CallingConv::X86_FastCall)
83 // Decorate names only when we're targeting Cygwin/Mingw32 targets
84 if (!Subtarget->isTargetCygMing())
87 FMFInfoMap::const_iterator info_item = FunctionInfoMap.find(F);
89 const X86MachineFunctionInfo *Info;
90 if (info_item == FunctionInfoMap.end()) {
91 // Calculate apropriate function info and populate map
92 FunctionInfoMap[F] = calculateFunctionInfo(F, TM.getTargetData());
93 Info = &FunctionInfoMap[F];
95 Info = &info_item->second;
98 const FunctionType *FT = F->getFunctionType();
99 switch (Info->getDecorationStyle()) {
103 // "Pure" variadic functions do not receive @0 suffix.
104 if (!FT->isVarArg() || (FT->getNumParams() == 0) ||
105 (FT->getNumParams() == 1 && F->hasStructRetAttr()))
106 Name += '@' + utostr_32(Info->getBytesToPopOnReturn());
109 // "Pure" variadic functions do not receive @0 suffix.
110 if (!FT->isVarArg() || (FT->getNumParams() == 0) ||
111 (FT->getNumParams() == 1 && F->hasStructRetAttr()))
112 Name += '@' + utostr_32(Info->getBytesToPopOnReturn());
114 if (Name[0] == '_') {
121 assert(0 && "Unsupported DecorationStyle");
126 bool X86SharedAsmPrinter::doInitialization(Module &M) {
127 if (TAI->doesSupportDebugInformation()) {
128 // Emit initial debug information.
132 bool Result = AsmPrinter::doInitialization(M);
134 // Darwin wants symbols to be quoted if they have complex names.
135 if (Subtarget->isTargetDarwin())
136 Mang->setUseQuotes(true);
141 /// PrintUnmangledNameSafely - Print out the printable characters in the name.
142 /// Don't print things like \n or \0.
143 static void PrintUnmangledNameSafely(const Value *V, std::ostream &OS) {
144 for (const char *Name = V->getNameStart(), *E = Name+V->getNameLen();
150 bool X86SharedAsmPrinter::doFinalization(Module &M) {
151 // Note: this code is not shared by the Intel printer as it is too different
152 // from how MASM does things. When making changes here don't forget to look
153 // at X86IntelAsmPrinter::doFinalization().
154 const TargetData *TD = TM.getTargetData();
156 // Print out module-level global variables here.
157 for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
159 if (!I->hasInitializer())
160 continue; // External global require no code
162 // Check to see if this is a special global used by LLVM, if so, emit it.
163 if (EmitSpecialLLVMGlobal(I)) {
164 if (Subtarget->isTargetDarwin() &&
165 TM.getRelocationModel() == Reloc::Static) {
166 if (I->getName() == "llvm.global_ctors")
167 O << ".reference .constructors_used\n";
168 else if (I->getName() == "llvm.global_dtors")
169 O << ".reference .destructors_used\n";
174 std::string name = Mang->getValueName(I);
175 Constant *C = I->getInitializer();
176 const Type *Type = C->getType();
177 unsigned Size = TD->getABITypeSize(Type);
178 unsigned Align = TD->getPreferredAlignmentLog(I);
180 if (I->hasHiddenVisibility()) {
181 if (const char *Directive = TAI->getHiddenDirective())
182 O << Directive << name << "\n";
183 } else if (I->hasProtectedVisibility()) {
184 if (const char *Directive = TAI->getProtectedDirective())
185 O << Directive << name << "\n";
188 if (Subtarget->isTargetELF())
189 O << "\t.type\t" << name << ",@object\n";
191 if (C->isNullValue() && !I->hasSection()) {
192 if (I->hasExternalLinkage()) {
193 if (const char *Directive = TAI->getZeroFillDirective()) {
194 O << "\t.globl " << name << "\n";
195 O << Directive << "__DATA, __common, " << name << ", "
196 << Size << ", " << Align << "\n";
201 if (!I->isThreadLocal() &&
202 (I->hasInternalLinkage() || I->hasWeakLinkage() ||
203 I->hasLinkOnceLinkage() || I->hasCommonLinkage())) {
204 if (Size == 0) Size = 1; // .comm Foo, 0 is undefined, avoid it.
205 if (!NoZerosInBSS && TAI->getBSSSection())
206 SwitchToDataSection(TAI->getBSSSection(), I);
208 SwitchToDataSection(TAI->getDataSection(), I);
209 if (TAI->getLCOMMDirective() != NULL) {
210 if (I->hasInternalLinkage()) {
211 O << TAI->getLCOMMDirective() << name << "," << Size;
212 if (Subtarget->isTargetDarwin())
214 } else if (Subtarget->isTargetDarwin() && !I->hasCommonLinkage()) {
215 O << "\t.globl " << name << "\n"
216 << TAI->getWeakDefDirective() << name << "\n";
217 SwitchToDataSection("\t.section __DATA,__datacoal_nt,coalesced", I);
218 EmitAlignment(Align, I);
219 O << name << ":\t\t\t\t" << TAI->getCommentString() << " ";
220 PrintUnmangledNameSafely(I, O);
222 EmitGlobalConstant(C);
225 O << TAI->getCOMMDirective() << name << "," << Size;
227 // Leopard and above support aligned common symbols.
228 if (Subtarget->getDarwinVers() >= 9)
232 if (!Subtarget->isTargetCygMing()) {
233 if (I->hasInternalLinkage())
234 O << "\t.local\t" << name << "\n";
236 O << TAI->getCOMMDirective() << name << "," << Size;
237 if (TAI->getCOMMDirectiveTakesAlignment())
238 O << "," << (TAI->getAlignmentIsInBytes() ? (1 << Align) : Align);
240 O << "\t\t" << TAI->getCommentString() << " ";
241 PrintUnmangledNameSafely(I, O);
247 switch (I->getLinkage()) {
248 case GlobalValue::CommonLinkage:
249 case GlobalValue::LinkOnceLinkage:
250 case GlobalValue::WeakLinkage:
251 if (Subtarget->isTargetDarwin()) {
252 O << "\t.globl " << name << "\n"
253 << TAI->getWeakDefDirective() << name << "\n";
254 if (!I->isConstant())
255 SwitchToDataSection("\t.section __DATA,__datacoal_nt,coalesced", I);
257 const ArrayType *AT = dyn_cast<ArrayType>(Type);
258 if (AT && AT->getElementType()==Type::Int8Ty)
259 SwitchToDataSection("\t.section __TEXT,__const_coal,coalesced", I);
261 SwitchToDataSection("\t.section __DATA,__const_coal,coalesced", I);
263 } else if (Subtarget->isTargetCygMing()) {
264 std::string SectionName(".section\t.data$linkonce." +
267 SwitchToDataSection(SectionName.c_str(), I);
268 O << "\t.globl\t" << name << "\n"
269 << "\t.linkonce same_size\n";
271 std::string SectionName("\t.section\t.llvm.linkonce.d." +
273 ",\"aw\",@progbits");
274 SwitchToDataSection(SectionName.c_str(), I);
275 O << "\t.weak\t" << name << "\n";
278 case GlobalValue::DLLExportLinkage:
279 DLLExportedGVs.insert(Mang->makeNameProper(I->getName(),""));
281 case GlobalValue::AppendingLinkage:
282 // FIXME: appending linkage variables should go into a section of
283 // their name or something. For now, just emit them as external.
284 case GlobalValue::ExternalLinkage:
285 // If external or appending, declare as a global symbol
286 O << "\t.globl " << name << "\n";
288 case GlobalValue::InternalLinkage: {
289 if (I->isConstant()) {
290 const ConstantArray *CVA = dyn_cast<ConstantArray>(C);
291 if (TAI->getCStringSection() && CVA && CVA->isCString()) {
292 SwitchToDataSection(TAI->getCStringSection(), I);
296 // FIXME: special handling for ".ctors" & ".dtors" sections
297 if (I->hasSection() &&
298 (I->getSection() == ".ctors" ||
299 I->getSection() == ".dtors")) {
300 std::string SectionName = ".section " + I->getSection();
302 if (Subtarget->isTargetCygMing()) {
303 SectionName += ",\"aw\"";
305 assert(!Subtarget->isTargetDarwin());
306 SectionName += ",\"aw\",@progbits";
308 SwitchToDataSection(SectionName.c_str());
309 } else if (I->hasSection() && Subtarget->isTargetDarwin()) {
310 // Honor all section names on Darwin; ObjC uses this
311 std::string SectionName = ".section " + I->getSection();
312 SwitchToDataSection(SectionName.c_str());
314 if (C->isNullValue() && !NoZerosInBSS && TAI->getBSSSection())
315 SwitchToDataSection(I->isThreadLocal() ? TAI->getTLSBSSSection() :
316 TAI->getBSSSection(), I);
317 else if (!I->isConstant())
318 SwitchToDataSection(I->isThreadLocal() ? TAI->getTLSDataSection() :
319 TAI->getDataSection(), I);
320 else if (I->isThreadLocal())
321 SwitchToDataSection(TAI->getTLSDataSection());
324 bool HasReloc = C->ContainsRelocations();
326 Subtarget->isTargetDarwin() &&
327 TM.getRelocationModel() != Reloc::Static)
328 SwitchToDataSection("\t.const_data\n");
329 else if (!HasReloc && Size == 4 &&
330 TAI->getFourByteConstantSection())
331 SwitchToDataSection(TAI->getFourByteConstantSection(), I);
332 else if (!HasReloc && Size == 8 &&
333 TAI->getEightByteConstantSection())
334 SwitchToDataSection(TAI->getEightByteConstantSection(), I);
335 else if (!HasReloc && Size == 16 &&
336 TAI->getSixteenByteConstantSection())
337 SwitchToDataSection(TAI->getSixteenByteConstantSection(), I);
338 else if (TAI->getReadOnlySection())
339 SwitchToDataSection(TAI->getReadOnlySection(), I);
341 SwitchToDataSection(TAI->getDataSection(), I);
348 assert(0 && "Unknown linkage type!");
351 EmitAlignment(Align, I);
352 O << name << ":\t\t\t\t" << TAI->getCommentString() << " ";
353 PrintUnmangledNameSafely(I, O);
355 if (TAI->hasDotTypeDotSizeDirective())
356 O << "\t.size\t" << name << ", " << Size << "\n";
357 // If the initializer is a extern weak symbol, remember to emit the weak
359 if (const GlobalValue *GV = dyn_cast<GlobalValue>(C))
360 if (GV->hasExternalWeakLinkage())
361 ExtWeakSymbols.insert(GV);
363 EmitGlobalConstant(C);
366 // Output linker support code for dllexported globals
367 if (!DLLExportedGVs.empty()) {
368 SwitchToDataSection(".section .drectve");
371 for (std::set<std::string>::iterator i = DLLExportedGVs.begin(),
372 e = DLLExportedGVs.end();
374 O << "\t.ascii \" -export:" << *i << ",data\"\n";
377 if (!DLLExportedFns.empty()) {
378 SwitchToDataSection(".section .drectve");
381 for (std::set<std::string>::iterator i = DLLExportedFns.begin(),
382 e = DLLExportedFns.end();
384 O << "\t.ascii \" -export:" << *i << "\"\n";
387 if (Subtarget->isTargetDarwin()) {
388 SwitchToDataSection("");
390 // Output stubs for dynamically-linked functions
392 for (std::set<std::string>::iterator i = FnStubs.begin(), e = FnStubs.end();
394 SwitchToDataSection("\t.section __IMPORT,__jump_table,symbol_stubs,"
395 "self_modifying_code+pure_instructions,5", 0);
397 printSuffixedName(p, "$stub");
399 O << "\t.indirect_symbol " << p << "\n";
400 O << "\thlt ; hlt ; hlt ; hlt ; hlt\n";
405 if (TAI->doesSupportExceptionHandling() && MMI && !Subtarget->is64Bit()) {
406 // Add the (possibly multiple) personalities to the set of global values.
407 // Only referenced functions get into the Personalities list.
408 const std::vector<Function *>& Personalities = MMI->getPersonalities();
410 for (std::vector<Function *>::const_iterator I = Personalities.begin(),
411 E = Personalities.end(); I != E; ++I)
412 if (*I) GVStubs.insert("_" + (*I)->getName());
415 // Output stubs for external and common global variables.
416 if (!GVStubs.empty())
418 "\t.section __IMPORT,__pointers,non_lazy_symbol_pointers");
419 for (std::set<std::string>::iterator i = GVStubs.begin(), e = GVStubs.end();
422 printSuffixedName(p, "$non_lazy_ptr");
424 O << "\t.indirect_symbol " << p << "\n";
428 // Emit final debug information.
431 // Funny Darwin hack: This flag tells the linker that no global symbols
432 // contain code that falls through to other global symbols (e.g. the obvious
433 // implementation of multiple entry points). If this doesn't occur, the
434 // linker can safely perform dead code stripping. Since LLVM never
435 // generates code that does this, it is always safe to set.
436 O << "\t.subsections_via_symbols\n";
437 } else if (Subtarget->isTargetCygMing()) {
438 // Emit type information for external functions
439 for (std::set<std::string>::iterator i = FnStubs.begin(), e = FnStubs.end();
441 O << "\t.def\t " << *i
442 << ";\t.scl\t" << COFF::C_EXT
443 << ";\t.type\t" << (COFF::DT_FCN << COFF::N_BTSHFT)
447 // Emit final debug information.
449 } else if (Subtarget->isTargetELF()) {
450 // Emit final debug information.
454 return AsmPrinter::doFinalization(M);
457 /// createX86CodePrinterPass - Returns a pass that prints the X86 assembly code
458 /// for a MachineFunction to the given output stream, using the given target
459 /// machine description.
461 FunctionPass *llvm::createX86CodePrinterPass(std::ostream &o,
462 X86TargetMachine &tm) {
463 const X86Subtarget *Subtarget = &tm.getSubtarget<X86Subtarget>();
465 if (Subtarget->isFlavorIntel()) {
466 return new X86IntelAsmPrinter(o, tm, tm.getTargetAsmInfo());
468 return new X86ATTAsmPrinter(o, tm, tm.getTargetAsmInfo());