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//===-- X86AsmPrinter.cpp - Convert X86 LLVM IR to X86 assembly -----------===//
//
// The LLVM Compiler Infrastructure
//
// This file was developed by the LLVM research group and is distributed under
// the University of Illinois Open Source License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file the shared super class printer that converts from our internal
// representation of machine-dependent LLVM code to Intel and AT&T format
// assembly language.
// This printer is the output mechanism used by `llc'.
//
//===----------------------------------------------------------------------===//
#include "X86ATTAsmPrinter.h"
#include "X86IntelAsmPrinter.h"
#include "X86Subtarget.h"
#include "X86.h"
#include "llvm/Module.h"
#include "llvm/Type.h"
#include "llvm/Assembly/Writer.h"
#include "llvm/Support/Mangler.h"
#include "llvm/Support/CommandLine.h"
using namespace llvm;
using namespace x86;
Statistic<> llvm::x86::EmittedInsts("asm-printer",
"Number of machine instrs printed");
enum AsmWriterFlavorTy { att, intel };
cl::opt<AsmWriterFlavorTy>
AsmWriterFlavor("x86-asm-syntax",
cl::desc("Choose style of code to emit from X86 backend:"),
cl::values(
clEnumVal(att, " Emit AT&T-style assembly"),
clEnumVal(intel, " Emit Intel-style assembly"),
clEnumValEnd),
cl::init(att));
/// doInitialization
bool X86SharedAsmPrinter::doInitialization(Module &M) {
const X86Subtarget *Subtarget = &TM.getSubtarget<X86Subtarget>();
forDarwin = false;
switch (Subtarget->TargetType) {
case X86Subtarget::isDarwin:
AlignmentIsInBytes = false;
GlobalPrefix = "_";
Data64bitsDirective = 0; // we can't emit a 64-bit unit
ZeroDirective = "\t.space\t"; // ".space N" emits N zeros.
PrivateGlobalPrefix = "L"; // Marker for constant pool idxs
ConstantPoolSection = "\t.const\n";
LCOMMDirective = "\t.lcomm\t";
COMMDirectiveTakesAlignment = false;
HasDotTypeDotSizeDirective = false;
forDarwin = true;
break;
case X86Subtarget::isCygwin:
GlobalPrefix = "_";
COMMDirectiveTakesAlignment = false;
HasDotTypeDotSizeDirective = false;
break;
case X86Subtarget::isWindows:
GlobalPrefix = "_";
HasDotTypeDotSizeDirective = false;
break;
default: break;
}
return AsmPrinter::doInitialization(M);
}
bool X86SharedAsmPrinter::doFinalization(Module &M) {
const TargetData &TD = TM.getTargetData();
// Print out module-level global variables here.
for (Module::const_global_iterator I = M.global_begin(),
E = M.global_end(); I != E; ++I) {
if (!I->hasInitializer()) continue; // External global require no code
O << "\n\n";
std::string name = Mang->getValueName(I);
Constant *C = I->getInitializer();
unsigned Size = TD.getTypeSize(C->getType());
unsigned Align = TD.getTypeAlignmentShift(C->getType());
switch (I->getLinkage()) {
default: assert(0 && "Unknown linkage type!");
case GlobalValue::LinkOnceLinkage:
case GlobalValue::WeakLinkage: // FIXME: Verify correct for weak.
if (C->isNullValue()) {
O << COMMDirective << name << "," << Size;
if (COMMDirectiveTakesAlignment)
O << "," << (1 << Align);
O << "\t\t" << CommentString << " " << I->getName() << "\n";
continue;
}
// Nonnull linkonce -> weak
O << "\t.weak " << name << "\n";
O << "\t.section\t.llvm.linkonce.d." << name << ",\"aw\",@progbits\n";
SwitchSection("", I);
break;
case GlobalValue::InternalLinkage:
if (C->isNullValue()) {
if (LCOMMDirective) {
O << LCOMMDirective << name << "," << Size << "," << Align;
continue;
} else {
SwitchSection(".bss", I);
O << "\t.local " << name << "\n";
O << COMMDirective << name << "," << Size;
if (COMMDirectiveTakesAlignment)
O << "," << (1 << Align);
O << "\t\t# ";
WriteAsOperand(O, I, true, true, &M);
O << "\n";
continue;
}
}
SwitchSection(".data", I);
break;
case GlobalValue::AppendingLinkage:
// FIXME: appending linkage variables should go into a section of
// their name or something. For now, just emit them as external.
case GlobalValue::ExternalLinkage:
SwitchSection(C->isNullValue() ? ".bss" : ".data", I);
// If external or appending, declare as a global symbol
O << "\t.globl " << name << "\n";
break;
}
EmitAlignment(Align);
if (HasDotTypeDotSizeDirective) {
O << "\t.type " << name << ",@object\n";
O << "\t.size " << name << "," << Size << "\n";
}
O << name << ":\t\t\t" << CommentString << ' ' << I->getName() << '\n';
EmitGlobalConstant(C);
}
if (forDarwin) {
SwitchSection("", 0);
// Output stubs for external global variables
if (GVStubs.begin() != GVStubs.end())
O << "\t.non_lazy_symbol_pointer\n";
for (std::set<std::string>::iterator i = GVStubs.begin(), e = GVStubs.end();
i != e; ++i) {
O << "L" << *i << "$non_lazy_ptr:\n";
O << "\t.indirect_symbol " << *i << "\n";
O << "\t.long\t0\n";
}
// Output stubs for dynamically-linked functions
unsigned j = 1;
for (std::set<std::string>::iterator i = FnStubs.begin(), e = FnStubs.end();
i != e; ++i, ++j) {
O << "\t.symbol_stub\n";
O << "L" << *i << "$stub:\n";
O << "\t.indirect_symbol " << *i << "\n";
O << "\tjmp\t*L" << j << "$lz\n";
O << "L" << *i << "$stub_binder:\n";
O << "\tpushl\t$L" << j << "$lz\n";
O << "\tjmp\tdyld_stub_binding_helper\n";
O << "\t.section __DATA, __la_sym_ptr3,lazy_symbol_pointers\n";
O << "L" << j << "$lz:\n";
O << "\t.indirect_symbol " << *i << "\n";
O << "\t.long\tL" << *i << "$stub_binder\n";
}
O << "\n";
// Output stubs for link-once variables
if (LinkOnceStubs.begin() != LinkOnceStubs.end())
O << ".data\n.align 2\n";
for (std::set<std::string>::iterator i = LinkOnceStubs.begin(),
e = LinkOnceStubs.end(); i != e; ++i) {
O << "L" << *i << "$non_lazy_ptr:\n"
<< "\t.long\t" << *i << '\n';
}
}
AsmPrinter::doFinalization(M);
return false; // success
}
/// createX86CodePrinterPass - Returns a pass that prints the X86 assembly code
/// for a MachineFunction to the given output stream, using the given target
/// machine description.
///
FunctionPass *llvm::createX86CodePrinterPass(std::ostream &o,TargetMachine &tm){
switch (AsmWriterFlavor) {
default:
assert(0 && "Unknown asm flavor!");
case intel:
return new X86IntelAsmPrinter(o, tm);
case att:
return new X86ATTAsmPrinter(o, tm);
}
}
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