llvm-6502/lib/Target/MBlaze/MBlazeAsmBackend.cpp
Wesley Peck 0a67d92938 Adding working version of assembly parser for the MBlaze backend
Major cleanup of whitespace and formatting issues in MBlaze backend


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@118434 91177308-0d34-0410-b5e6-96231b3b80d8
2010-11-08 19:40:01 +00:00

154 lines
4.3 KiB
C++

//===-- 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 "MBlazeFixupKinds.h"
#include "llvm/ADT/Twine.h"
#include "llvm/MC/ELFObjectWriter.h"
#include "llvm/MC/MCAssembler.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/MachObjectWriter.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;
}
};
bool MBlazeAsmBackend::MayNeedRelaxation(const MCInst &Inst) const {
return false;
}
void MBlazeAsmBackend::RelaxInstruction(const MCInst &Inst, MCInst &Res) const {
assert(0 && "MBlazeAsmBackend::RelaxInstruction() unimplemented");
return;
}
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 {
// FIXME: This should be in a separate file.
// ELF is an ELF of course...
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;
bool isVirtualSection(const MCSection &Section) const {
const MCSectionELF &SE = static_cast<const MCSectionELF&>(Section);
return SE.getType() == MCSectionELF::SHT_NOBITS;
}
MCObjectWriter *createObjectWriter(raw_ostream &OS) const {
return new ELFObjectWriter(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());
}
}