llvm-6502/lib/Target/AArch64/AArch64TargetObjectFile.cpp
Bruno Cardoso Lopes 66aa390799 [AsmPrinter][TLOF] ARM64 MachO support for replacing GOT equivalents
Follow up r230264 and add ARM64 support for replacing global GOT
equivalent symbol accesses by references to the GOT entry for the final
symbol instead, example:

-- before

   .globl  _foo
  _foo:
   .long   42

   .globl  _gotequivalent
  _gotequivalent:
   .quad   _foo

   .globl  _delta
  _delta:
   .long   _gotequivalent-_delta

-- after

   .globl  _foo
  _foo:
   .long   42

   .globl  _delta
  Ltmp3:
   .long _foo@GOT-Ltmp3

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231474 91177308-0d34-0410-b5e6-96231b3b80d8
2015-03-06 13:48:45 +00:00

71 lines
2.7 KiB
C++

//===-- AArch64TargetObjectFile.cpp - AArch64 Object Info -----------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "AArch64TargetObjectFile.h"
#include "AArch64TargetMachine.h"
#include "llvm/IR/Mangler.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCStreamer.h"
#include "llvm/Support/Dwarf.h"
using namespace llvm;
using namespace dwarf;
void AArch64_ELFTargetObjectFile::Initialize(MCContext &Ctx,
const TargetMachine &TM) {
TargetLoweringObjectFileELF::Initialize(Ctx, TM);
InitializeELF(TM.Options.UseInitArray);
}
AArch64_MachoTargetObjectFile::AArch64_MachoTargetObjectFile()
: TargetLoweringObjectFileMachO() {
SupportIndirectSymViaGOTPCRel = true;
SupportGOTPCRelWithOffset = false;
}
const MCExpr *AArch64_MachoTargetObjectFile::getTTypeGlobalReference(
const GlobalValue *GV, unsigned Encoding, Mangler &Mang,
const TargetMachine &TM, MachineModuleInfo *MMI,
MCStreamer &Streamer) const {
// On Darwin, we can reference dwarf symbols with foo@GOT-., which
// is an indirect pc-relative reference. The default implementation
// won't reference using the GOT, so we need this target-specific
// version.
if (Encoding & (DW_EH_PE_indirect | DW_EH_PE_pcrel)) {
const MCSymbol *Sym = TM.getSymbol(GV, Mang);
const MCExpr *Res =
MCSymbolRefExpr::Create(Sym, MCSymbolRefExpr::VK_GOT, getContext());
MCSymbol *PCSym = getContext().CreateTempSymbol();
Streamer.EmitLabel(PCSym);
const MCExpr *PC = MCSymbolRefExpr::Create(PCSym, getContext());
return MCBinaryExpr::CreateSub(Res, PC, getContext());
}
return TargetLoweringObjectFileMachO::getTTypeGlobalReference(
GV, Encoding, Mang, TM, MMI, Streamer);
}
MCSymbol *AArch64_MachoTargetObjectFile::getCFIPersonalitySymbol(
const GlobalValue *GV, Mangler &Mang, const TargetMachine &TM,
MachineModuleInfo *MMI) const {
return TM.getSymbol(GV, Mang);
}
const MCExpr *AArch64_MachoTargetObjectFile::getIndirectSymViaGOTPCRel(
const MCSymbol *Sym, int64_t Offset, MCStreamer &Streamer) const {
// On ARM64 Darwin, we can reference symbols with foo@GOT-., which
// is an indirect pc-relative reference.
const MCExpr *Res =
MCSymbolRefExpr::Create(Sym, MCSymbolRefExpr::VK_GOT, getContext());
MCSymbol *PCSym = getContext().CreateTempSymbol();
Streamer.EmitLabel(PCSym);
const MCExpr *PC = MCSymbolRefExpr::Create(PCSym, getContext());
return MCBinaryExpr::CreateSub(Res, PC, getContext());
}