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 "X86ATTAsmPrinter.h"
18 #include "X86IntelAsmPrinter.h"
19 #include "X86Subtarget.h"
21 #include "llvm/Constants.h"
22 #include "llvm/Module.h"
23 #include "llvm/Type.h"
24 #include "llvm/Assembly/Writer.h"
25 #include "llvm/Support/Mangler.h"
26 #include "llvm/Support/CommandLine.h"
30 Statistic<> llvm::x86::EmittedInsts("asm-printer",
31 "Number of machine instrs printed");
33 enum AsmWriterFlavorTy { att, intel };
34 cl::opt<AsmWriterFlavorTy>
35 AsmWriterFlavor("x86-asm-syntax",
36 cl::desc("Choose style of code to emit from X86 backend:"),
38 clEnumVal(att, " Emit AT&T-style assembly"),
39 clEnumVal(intel, " Emit Intel-style assembly"),
44 bool X86SharedAsmPrinter::doInitialization(Module &M) {
45 const X86Subtarget *Subtarget = &TM.getSubtarget<X86Subtarget>();
49 switch (Subtarget->TargetType) {
50 case X86Subtarget::isDarwin:
51 AlignmentIsInBytes = false;
53 Data64bitsDirective = 0; // we can't emit a 64-bit unit
54 ZeroDirective = "\t.space\t"; // ".space N" emits N zeros.
55 PrivateGlobalPrefix = "L"; // Marker for constant pool idxs
56 ConstantPoolSection = "\t.const\n";
57 LCOMMDirective = "\t.lcomm\t";
58 COMMDirectiveTakesAlignment = false;
59 HasDotTypeDotSizeDirective = false;
61 StaticCtorsSection = ".mod_init_func";
62 StaticDtorsSection = ".mod_term_func";
64 case X86Subtarget::isCygwin:
66 COMMDirectiveTakesAlignment = false;
67 HasDotTypeDotSizeDirective = false;
69 case X86Subtarget::isWindows:
71 HasDotTypeDotSizeDirective = false;
76 return AsmPrinter::doInitialization(M);
79 bool X86SharedAsmPrinter::doFinalization(Module &M) {
80 const TargetData &TD = TM.getTargetData();
82 // Print out module-level global variables here.
83 for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
85 if (!I->hasInitializer()) continue; // External global require no code
87 // Check to see if this is a special global used by LLVM, if so, emit it.
88 if (I->hasAppendingLinkage() && EmitSpecialLLVMGlobal(I))
91 std::string name = Mang->getValueName(I);
92 Constant *C = I->getInitializer();
93 unsigned Size = TD.getTypeSize(C->getType());
94 unsigned Align = getPreferredAlignmentLog(I);
96 if (C->isNullValue() && /* FIXME: Verify correct */
97 (I->hasInternalLinkage() || I->hasWeakLinkage() ||
98 I->hasLinkOnceLinkage())) {
99 if (Size == 0) Size = 1; // .comm Foo, 0 is undefined, avoid it.
100 SwitchSection(".data", I);
101 if (LCOMMDirective != NULL) {
102 if (I->hasInternalLinkage()) {
103 O << LCOMMDirective << name << "," << Size;
105 O << "," << (AlignmentIsInBytes ? (1 << Align) : Align);
107 O << COMMDirective << name << "," << Size;
109 if (I->hasInternalLinkage())
110 O <<"\t.local\t" << name << "\n";
111 O << COMMDirective << name << "," << Size;
112 if (COMMDirectiveTakesAlignment)
113 O << "," << (AlignmentIsInBytes ? (1 << Align) : Align);
115 O << "\t\t" << CommentString << " " << I->getName() << "\n";
117 switch (I->getLinkage()) {
118 case GlobalValue::LinkOnceLinkage:
119 case GlobalValue::WeakLinkage:
121 O << "\t.globl " << name << "\n"
122 << "\t.weak_definition " << name << "\n";
123 SwitchSection(".section __DATA,__datacoal_nt,coalesced", I);
125 O << "\t.section\t.llvm.linkonce.d." << name << ",\"aw\",@progbits\n";
126 O << "\t.weak " << name << "\n";
129 case GlobalValue::AppendingLinkage:
130 // FIXME: appending linkage variables should go into a section of
131 // their name or something. For now, just emit them as external.
132 case GlobalValue::ExternalLinkage:
133 // If external or appending, declare as a global symbol
134 O << "\t.globl " << name << "\n";
136 case GlobalValue::InternalLinkage:
137 SwitchSection(".data", I);
140 assert(0 && "Unknown linkage type!");
143 EmitAlignment(Align, I);
144 O << name << ":\t\t\t\t" << CommentString << " " << I->getName()
146 if (HasDotTypeDotSizeDirective)
147 O << "\t.size " << name << ", " << Size << "\n";
149 EmitGlobalConstant(C);
155 SwitchSection("", 0);
157 // Output stubs for dynamically-linked functions
159 for (std::set<std::string>::iterator i = FnStubs.begin(), e = FnStubs.end();
161 SwitchSection(".section __IMPORT,__jump_table,symbol_stubs,"
162 "self_modifying_code+pure_instructions,5", 0);
163 O << "L" << *i << "$stub:\n";
164 O << "\t.indirect_symbol " << *i << "\n";
165 O << "\thlt ; hlt ; hlt ; hlt ; hlt\n";
170 // Output stubs for external and common global variables.
171 if (GVStubs.begin() != GVStubs.end())
172 SwitchSection(".section __IMPORT,__pointers,non_lazy_symbol_pointers", 0);
173 for (std::set<std::string>::iterator i = GVStubs.begin(), e = GVStubs.end();
175 O << "L" << *i << "$non_lazy_ptr:\n";
176 O << "\t.indirect_symbol " << *i << "\n";
181 AsmPrinter::doFinalization(M);
182 return false; // success
185 /// createX86CodePrinterPass - Returns a pass that prints the X86 assembly code
186 /// for a MachineFunction to the given output stream, using the given target
187 /// machine description.
189 FunctionPass *llvm::createX86CodePrinterPass(std::ostream &o,TargetMachine &tm){
190 switch (AsmWriterFlavor) {
192 assert(0 && "Unknown asm flavor!");
194 return new X86IntelAsmPrinter(o, tm);
196 return new X86ATTAsmPrinter(o, tm);