llvm-6502/lib/Target/X86/X86TargetObjectFile.h
David Majnemer 38d8be1ad8 CodeGen: Stick constant pool entries in COMDAT sections for WinCOFF
COFF lacks a feature that other object file formats support: mergeable
sections.

To work around this, MSVC sticks constant pool entries in special COMDAT
sections so that each constant is in it's own section.  This permits
unused constants to be dropped and it also allows duplicate constants in
different translation units to get merged together.

This fixes PR20262.

Differential Revision: http://reviews.llvm.org/D4482

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213006 91177308-0d34-0410-b5e6-96231b3b80d8
2014-07-14 22:57:27 +00:00

59 lines
2.3 KiB
C++

//===-- X86TargetObjectFile.h - X86 Object Info -----------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_TARGET_X86_TARGETOBJECTFILE_H
#define LLVM_TARGET_X86_TARGETOBJECTFILE_H
#include "llvm/CodeGen/TargetLoweringObjectFileImpl.h"
#include "llvm/Target/TargetLoweringObjectFile.h"
namespace llvm {
/// X86_64MachoTargetObjectFile - This TLOF implementation is used for Darwin
/// x86-64.
class X86_64MachoTargetObjectFile : public TargetLoweringObjectFileMachO {
public:
const MCExpr *
getTTypeGlobalReference(const GlobalValue *GV, unsigned Encoding,
Mangler &Mang, const TargetMachine &TM,
MachineModuleInfo *MMI,
MCStreamer &Streamer) const override;
// getCFIPersonalitySymbol - The symbol that gets passed to
// .cfi_personality.
MCSymbol *getCFIPersonalitySymbol(const GlobalValue *GV, Mangler &Mang,
const TargetMachine &TM,
MachineModuleInfo *MMI) const override;
};
/// X86LinuxTargetObjectFile - This implementation is used for linux x86
/// and x86-64.
class X86LinuxTargetObjectFile : public TargetLoweringObjectFileELF {
void Initialize(MCContext &Ctx, const TargetMachine &TM) override;
/// \brief Describe a TLS variable address within debug info.
const MCExpr *getDebugThreadLocalSymbol(const MCSymbol *Sym) const override;
};
/// \brief This implementation is used for Windows targets on x86 and x86-64.
class X86WindowsTargetObjectFile : public TargetLoweringObjectFileCOFF {
const MCExpr *
getExecutableRelativeSymbol(const ConstantExpr *CE, Mangler &Mang,
const TargetMachine &TM) const override;
/// \brief Given a mergeable constant with the specified size and relocation
/// information, return a section that it should be placed in.
const MCSection *getSectionForConstant(SectionKind Kind,
const Constant *C) const override;
};
} // end namespace llvm
#endif