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//===-- MBlazeAsmBackend.cpp - MBlaze Assembler Backend -------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "llvm/Target/TargetAsmBackend.h"
#include "MBlaze.h"
#include "MBlazeELFWriterInfo.h"
#include "MBlazeFixupKinds.h"
#include "llvm/ADT/Twine.h"
#include "llvm/MC/MCAssembler.h"
#include "llvm/MC/MCAsmLayout.h"
#include "llvm/MC/MCELFSymbolFlags.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCObjectFormat.h"
#include "llvm/MC/MCObjectWriter.h"
#include "llvm/MC/MCSectionELF.h"
#include "llvm/MC/MCSectionMachO.h"
#include "llvm/MC/MCValue.h"
#include "llvm/Support/ELF.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Target/TargetRegistry.h"
#include "llvm/Target/TargetAsmBackend.h"
using namespace llvm;
static unsigned getFixupKindSize(unsigned Kind) {
switch (Kind) {
default: assert(0 && "invalid fixup kind!");
case FK_Data_1: return 1;
case MBlaze::reloc_pcrel_2byte:
case FK_Data_2: return 2;
case MBlaze::reloc_pcrel_4byte:
case FK_Data_4: return 4;
case FK_Data_8: return 8;
}
}
namespace {
class MBlazeAsmBackend : public TargetAsmBackend {
public:
MBlazeAsmBackend(const Target &T)
: TargetAsmBackend(T) {
}
bool MayNeedRelaxation(const MCInst &Inst) const;
void RelaxInstruction(const MCInst &Inst, MCInst &Res) const;
bool WriteNopData(uint64_t Count, MCObjectWriter *OW) const;
unsigned getPointerSize() const {
return 4;
}
};
static unsigned getRelaxedOpcode(unsigned Op) {
switch (Op) {
default: return Op;
case MBlaze::ADDI: return MBlaze::ADDI32;
case MBlaze::ORI: return MBlaze::ORI32;
case MBlaze::BRLID: return MBlaze::BRLID32;
}
}
bool MBlazeAsmBackend::MayNeedRelaxation(const MCInst &Inst) const {
if (getRelaxedOpcode(Inst.getOpcode()) == Inst.getOpcode())
return false;
bool hasExprOrImm = false;
for (unsigned i = 0; i < Inst.getNumOperands(); ++i)
hasExprOrImm |= Inst.getOperand(i).isExpr();
return hasExprOrImm;
}
void MBlazeAsmBackend::RelaxInstruction(const MCInst &Inst, MCInst &Res) const {
Res = Inst;
Res.setOpcode(getRelaxedOpcode(Inst.getOpcode()));
}
bool MBlazeAsmBackend::WriteNopData(uint64_t Count, MCObjectWriter *OW) const {
if ((Count % 4) != 0)
return false;
for (uint64_t i = 0; i < Count; i += 4)
OW->Write32(0x00000000);
return true;
}
} // end anonymous namespace
namespace {
class ELFMBlazeAsmBackend : public MBlazeAsmBackend {
MCELFObjectFormat Format;
public:
Triple::OSType OSType;
ELFMBlazeAsmBackend(const Target &T, Triple::OSType _OSType)
: MBlazeAsmBackend(T), OSType(_OSType) {
HasScatteredSymbols = true;
}
virtual const MCObjectFormat &getObjectFormat() const {
return Format;
}
void ApplyFixup(const MCFixup &Fixup, MCDataFragment &DF,
uint64_t Value) const;
MCObjectWriter *createObjectWriter(raw_ostream &OS) const {
return createELFObjectWriter(OS,/*Is64Bit=*/false,
OSType, ELF::EM_MBLAZE,
/*IsLittleEndian=*/false,
/*HasRelocationAddend=*/true);
}
};
void ELFMBlazeAsmBackend::ApplyFixup(const MCFixup &Fixup, MCDataFragment &DF,
uint64_t Value) const {
unsigned Size = getFixupKindSize(Fixup.getKind());
assert(Fixup.getOffset() + Size <= DF.getContents().size() &&
"Invalid fixup offset!");
char *data = DF.getContents().data() + Fixup.getOffset();
switch (Size) {
default: llvm_unreachable("Cannot fixup unknown value.");
case 1: llvm_unreachable("Cannot fixup 1 byte value.");
case 8: llvm_unreachable("Cannot fixup 8 byte value.");
case 4:
*(data+7) = uint8_t(Value);
*(data+6) = uint8_t(Value >> 8);
*(data+3) = uint8_t(Value >> 16);
*(data+2) = uint8_t(Value >> 24);
break;
case 2:
*(data+3) = uint8_t(Value >> 0);
*(data+2) = uint8_t(Value >> 8);
}
}
} // end anonymous namespace
TargetAsmBackend *llvm::createMBlazeAsmBackend(const Target &T,
const std::string &TT) {
switch (Triple(TT).getOS()) {
case Triple::Darwin:
assert(0 && "Mac not supported on MBlaze");
case Triple::MinGW32:
case Triple::Cygwin:
case Triple::Win32:
assert(0 && "Windows not supported on MBlaze");
default:
return new ELFMBlazeAsmBackend(T, Triple(TT).getOS());
}
}
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