1 //===-- X86AsmPrinter.cpp - Convert X86 LLVM IR to X86 assembly -----------===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by the LLVM research group and is distributed under
6 // the University of Illinois Open Source 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/Type.h"
29 #include "llvm/Assembly/Writer.h"
30 #include "llvm/Support/Mangler.h"
31 #include "llvm/Target/TargetAsmInfo.h"
32 #include "llvm/Target/TargetOptions.h"
35 static X86MachineFunctionInfo calculateFunctionInfo(const Function *F,
36 const TargetData *TD) {
37 X86MachineFunctionInfo Info;
40 switch (F->getCallingConv()) {
41 case CallingConv::X86_StdCall:
42 Info.setDecorationStyle(StdCall);
44 case CallingConv::X86_FastCall:
45 Info.setDecorationStyle(FastCall);
51 for (Function::const_arg_iterator AI = F->arg_begin(), AE = F->arg_end();
53 // Size should be aligned to DWORD boundary
54 Size += ((TD->getTypeSize(AI->getType()) + 3)/4)*4;
56 // We're not supporting tooooo huge arguments :)
57 Info.setBytesToPopOnReturn((unsigned int)Size);
62 /// decorateName - Query FunctionInfoMap and use this information for various
64 void X86SharedAsmPrinter::decorateName(std::string &Name,
65 const GlobalValue *GV) {
66 const Function *F = dyn_cast<Function>(GV);
69 // We don't want to decorate non-stdcall or non-fastcall functions right now
70 unsigned CC = F->getCallingConv();
71 if (CC != CallingConv::X86_StdCall && CC != CallingConv::X86_FastCall)
74 // Decorate names only when we're targeting Cygwin/Mingw32 targets
75 if (!Subtarget->isTargetCygMing())
78 FMFInfoMap::const_iterator info_item = FunctionInfoMap.find(F);
80 const X86MachineFunctionInfo *Info;
81 if (info_item == FunctionInfoMap.end()) {
82 // Calculate apropriate function info and populate map
83 FunctionInfoMap[F] = calculateFunctionInfo(F, TM.getTargetData());
84 Info = &FunctionInfoMap[F];
86 Info = &info_item->second;
89 const FunctionType *FT = F->getFunctionType();
90 switch (Info->getDecorationStyle()) {
94 // "Pure" variadic functions do not receive @0 suffix.
95 if (!FT->isVarArg() || (FT->getNumParams() == 0) ||
96 (FT->getNumParams() == 1 && FT->isStructReturn()))
97 Name += '@' + utostr_32(Info->getBytesToPopOnReturn());
100 // "Pure" variadic functions do not receive @0 suffix.
101 if (!FT->isVarArg() || (FT->getNumParams() == 0) ||
102 (FT->getNumParams() == 1 && FT->isStructReturn()))
103 Name += '@' + utostr_32(Info->getBytesToPopOnReturn());
105 if (Name[0] == '_') {
112 assert(0 && "Unsupported DecorationStyle");
117 bool X86SharedAsmPrinter::doInitialization(Module &M) {
118 if (TAI->doesSupportDebugInformation()) {
119 // Emit initial debug information.
123 bool Result = AsmPrinter::doInitialization(M);
125 // Darwin wants symbols to be quoted if they have complex names.
126 if (Subtarget->isTargetDarwin())
127 Mang->setUseQuotes(true);
132 bool X86SharedAsmPrinter::doFinalization(Module &M) {
133 // Note: this code is not shared by the Intel printer as it is too different
134 // from how MASM does things. When making changes here don't forget to look
135 // at X86IntelAsmPrinter::doFinalization().
136 const TargetData *TD = TM.getTargetData();
138 // Print out module-level global variables here.
139 for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
141 if (!I->hasInitializer())
142 continue; // External global require no code
144 // Check to see if this is a special global used by LLVM, if so, emit it.
145 if (EmitSpecialLLVMGlobal(I)) {
146 if (Subtarget->isTargetDarwin() &&
147 TM.getRelocationModel() == Reloc::Static) {
148 if (I->getName() == "llvm.global_ctors")
149 O << ".reference .constructors_used\n";
150 else if (I->getName() == "llvm.global_dtors")
151 O << ".reference .destructors_used\n";
156 std::string name = Mang->getValueName(I);
157 Constant *C = I->getInitializer();
158 const Type *Type = C->getType();
159 unsigned Size = TD->getTypeSize(Type);
160 unsigned Align = TD->getPreferredAlignmentLog(I);
162 if (I->hasHiddenVisibility()) {
163 if (const char *Directive = TAI->getHiddenDirective())
164 O << Directive << name << "\n";
165 } else if (I->hasProtectedVisibility()) {
166 if (const char *Directive = TAI->getProtectedDirective())
167 O << Directive << name << "\n";
170 if (Subtarget->isTargetELF())
171 O << "\t.type\t" << name << ",@object\n";
173 if (C->isNullValue()) {
174 if (I->hasExternalLinkage()) {
175 if (const char *Directive = TAI->getZeroFillDirective()) {
176 O << "\t.globl\t" << name << "\n";
177 O << Directive << "__DATA__, __common, " << name << ", "
178 << Size << ", " << Align << "\n";
183 if (!I->hasSection() && !I->isThreadLocal() &&
184 (I->hasInternalLinkage() || I->hasWeakLinkage() ||
185 I->hasLinkOnceLinkage())) {
186 if (Size == 0) Size = 1; // .comm Foo, 0 is undefined, avoid it.
187 if (!NoZerosInBSS && TAI->getBSSSection())
188 SwitchToDataSection(TAI->getBSSSection(), I);
190 SwitchToDataSection(TAI->getDataSection(), I);
191 if (TAI->getLCOMMDirective() != NULL) {
192 if (I->hasInternalLinkage()) {
193 O << TAI->getLCOMMDirective() << name << "," << Size;
194 if (Subtarget->isTargetDarwin())
197 O << TAI->getCOMMDirective() << name << "," << Size;
199 if (!Subtarget->isTargetCygMing()) {
200 if (I->hasInternalLinkage())
201 O << "\t.local\t" << name << "\n";
203 O << TAI->getCOMMDirective() << name << "," << Size;
204 if (TAI->getCOMMDirectiveTakesAlignment())
205 O << "," << (TAI->getAlignmentIsInBytes() ? (1 << Align) : Align);
207 O << "\t\t" << TAI->getCommentString() << " " << I->getName() << "\n";
212 switch (I->getLinkage()) {
213 case GlobalValue::LinkOnceLinkage:
214 case GlobalValue::WeakLinkage:
215 if (Subtarget->isTargetDarwin()) {
216 O << "\t.globl " << name << "\n"
217 << "\t.weak_definition " << name << "\n";
218 SwitchToDataSection(".section __DATA,__const_coal,coalesced", I);
219 } else if (Subtarget->isTargetCygMing()) {
220 std::string SectionName(".section\t.data$linkonce." +
223 SwitchToDataSection(SectionName.c_str(), I);
224 O << "\t.globl " << name << "\n"
225 << "\t.linkonce same_size\n";
227 std::string SectionName("\t.section\t.llvm.linkonce.d." +
229 ",\"aw\",@progbits");
230 SwitchToDataSection(SectionName.c_str(), I);
231 O << "\t.weak\t" << name << "\n";
234 case GlobalValue::AppendingLinkage:
235 // FIXME: appending linkage variables should go into a section of
236 // their name or something. For now, just emit them as external.
237 case GlobalValue::DLLExportLinkage:
238 DLLExportedGVs.insert(Mang->makeNameProper(I->getName(),""));
240 case GlobalValue::ExternalLinkage:
241 // If external or appending, declare as a global symbol
242 O << "\t.globl " << name << "\n";
244 case GlobalValue::InternalLinkage: {
245 if (I->isConstant()) {
246 const ConstantArray *CVA = dyn_cast<ConstantArray>(C);
247 if (TAI->getCStringSection() && CVA && CVA->isCString()) {
248 SwitchToDataSection(TAI->getCStringSection(), I);
252 // FIXME: special handling for ".ctors" & ".dtors" sections
253 if (I->hasSection() &&
254 (I->getSection() == ".ctors" ||
255 I->getSection() == ".dtors")) {
256 std::string SectionName = ".section " + I->getSection();
258 if (Subtarget->isTargetCygMing()) {
259 SectionName += ",\"aw\"";
261 assert(!Subtarget->isTargetDarwin());
262 SectionName += ",\"aw\",@progbits";
265 SwitchToDataSection(SectionName.c_str());
267 if (C->isNullValue() && !NoZerosInBSS && TAI->getBSSSection())
268 SwitchToDataSection(I->isThreadLocal() ? TAI->getTLSBSSSection() :
269 TAI->getBSSSection(), I);
270 else if (!I->isConstant())
271 SwitchToDataSection(I->isThreadLocal() ? TAI->getTLSDataSection() :
272 TAI->getDataSection(), I);
273 else if (I->isThreadLocal())
274 SwitchToDataSection(TAI->getTLSDataSection());
277 bool HasReloc = C->ContainsRelocations();
279 Subtarget->isTargetDarwin() &&
280 TM.getRelocationModel() != Reloc::Static)
281 SwitchToDataSection("\t.const_data\n");
282 else if (!HasReloc && Size == 4 &&
283 TAI->getFourByteConstantSection())
284 SwitchToDataSection(TAI->getFourByteConstantSection(), I);
285 else if (!HasReloc && Size == 8 &&
286 TAI->getEightByteConstantSection())
287 SwitchToDataSection(TAI->getEightByteConstantSection(), I);
288 else if (!HasReloc && Size == 16 &&
289 TAI->getSixteenByteConstantSection())
290 SwitchToDataSection(TAI->getSixteenByteConstantSection(), I);
291 else if (TAI->getReadOnlySection())
292 SwitchToDataSection(TAI->getReadOnlySection(), I);
294 SwitchToDataSection(TAI->getDataSection(), I);
301 assert(0 && "Unknown linkage type!");
304 EmitAlignment(Align, I);
305 O << name << ":\t\t\t\t" << TAI->getCommentString() << " " << I->getName()
307 if (TAI->hasDotTypeDotSizeDirective())
308 O << "\t.size\t" << name << ", " << Size << "\n";
309 // If the initializer is a extern weak symbol, remember to emit the weak
311 if (const GlobalValue *GV = dyn_cast<GlobalValue>(C))
312 if (GV->hasExternalWeakLinkage())
313 ExtWeakSymbols.insert(GV);
315 EmitGlobalConstant(C);
318 // Output linker support code for dllexported globals
319 if (DLLExportedGVs.begin() != DLLExportedGVs.end()) {
320 SwitchToDataSection(".section .drectve");
323 for (std::set<std::string>::iterator i = DLLExportedGVs.begin(),
324 e = DLLExportedGVs.end();
326 O << "\t.ascii \" -export:" << *i << ",data\"\n";
329 if (DLLExportedFns.begin() != DLLExportedFns.end()) {
330 SwitchToDataSection(".section .drectve");
333 for (std::set<std::string>::iterator i = DLLExportedFns.begin(),
334 e = DLLExportedFns.end();
336 O << "\t.ascii \" -export:" << *i << "\"\n";
339 if (Subtarget->isTargetDarwin()) {
340 SwitchToDataSection("");
342 // Output stubs for dynamically-linked functions
344 for (std::set<std::string>::iterator i = FnStubs.begin(), e = FnStubs.end();
346 SwitchToDataSection(".section __IMPORT,__jump_table,symbol_stubs,"
347 "self_modifying_code+pure_instructions,5", 0);
348 O << "L" << *i << "$stub:\n";
349 O << "\t.indirect_symbol " << *i << "\n";
350 O << "\thlt ; hlt ; hlt ; hlt ; hlt\n";
355 // Output stubs for external and common global variables.
356 if (GVStubs.begin() != GVStubs.end())
358 ".section __IMPORT,__pointers,non_lazy_symbol_pointers");
359 for (std::set<std::string>::iterator i = GVStubs.begin(), e = GVStubs.end();
361 O << "L" << *i << "$non_lazy_ptr:\n";
362 O << "\t.indirect_symbol " << *i << "\n";
366 // Emit final debug information.
369 // Funny Darwin hack: This flag tells the linker that no global symbols
370 // contain code that falls through to other global symbols (e.g. the obvious
371 // implementation of multiple entry points). If this doesn't occur, the
372 // linker can safely perform dead code stripping. Since LLVM never
373 // generates code that does this, it is always safe to set.
374 O << "\t.subsections_via_symbols\n";
375 } else if (Subtarget->isTargetCygMing()) {
376 // Emit type information for external functions
377 for (std::set<std::string>::iterator i = FnStubs.begin(), e = FnStubs.end();
379 O << "\t.def\t " << *i
380 << ";\t.scl\t" << COFF::C_EXT
381 << ";\t.type\t" << (COFF::DT_FCN << COFF::N_BTSHFT)
385 // Emit final debug information.
387 } else if (Subtarget->isTargetELF()) {
388 // Emit final debug information.
392 return AsmPrinter::doFinalization(M);
395 /// createX86CodePrinterPass - Returns a pass that prints the X86 assembly code
396 /// for a MachineFunction to the given output stream, using the given target
397 /// machine description.
399 FunctionPass *llvm::createX86CodePrinterPass(std::ostream &o,
400 X86TargetMachine &tm) {
401 const X86Subtarget *Subtarget = &tm.getSubtarget<X86Subtarget>();
403 if (Subtarget->isFlavorIntel()) {
404 return new X86IntelAsmPrinter(o, tm, tm.getTargetAsmInfo());
406 return new X86ATTAsmPrinter(o, tm, tm.getTargetAsmInfo());