llvm-6502/lib/Target/MBlaze/MBlazeTargetMachine.cpp

//===-- MBlazeTargetMachine.cpp - Define TargetMachine for MBlaze ---------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// Implements the info about MBlaze target spec.
//
//===----------------------------------------------------------------------===//

#include "MBlaze.h"
#include "MBlazeMCAsmInfo.h"
#include "MBlazeTargetMachine.h"
#include "llvm/PassManager.h"
#include "llvm/CodeGen/Passes.h"
#include "llvm/Support/FormattedStream.h"
#include "llvm/Target/TargetOptions.h"
#include "llvm/Target/TargetRegistry.h"
using namespace llvm;

static MCAsmInfo *createMCAsmInfo(const Target &T, StringRef TT) {
  Triple TheTriple(TT);
  switch (TheTriple.getOS()) {
  default:
    return new MBlazeMCAsmInfo();
  }
}

static MCStreamer *createMCStreamer(const Target &T, const std::string &TT,
                                    MCContext &Ctx, TargetAsmBackend &TAB,
                                    raw_ostream &_OS,
                                    MCCodeEmitter *_Emitter,
                                    bool RelaxAll,
                                    bool NoExecStack) {
  Triple TheTriple(TT);

  if (TheTriple.isOSDarwin()) {
    llvm_unreachable("MBlaze does not support Darwin MACH-O format");
    return NULL;
  }

  if (TheTriple.isOSWindows()) {
    llvm_unreachable("MBlaze does not support Windows COFF format");
    return NULL;
  }

  return createELFStreamer(Ctx, TAB, _OS, _Emitter, RelaxAll, NoExecStack);
}


extern "C" void LLVMInitializeMBlazeTarget() {
  // Register the target.
  RegisterTargetMachine<MBlazeTargetMachine> X(TheMBlazeTarget);

  // Register the target asm info.
  RegisterAsmInfoFn A(TheMBlazeTarget, createMCAsmInfo);

  // Register the MC code emitter
  TargetRegistry::RegisterCodeEmitter(TheMBlazeTarget,
                                      llvm::createMBlazeMCCodeEmitter);

  // Register the asm backend
  TargetRegistry::RegisterAsmBackend(TheMBlazeTarget,
                                     createMBlazeAsmBackend);

  // Register the object streamer
  TargetRegistry::RegisterObjectStreamer(TheMBlazeTarget,
                                         createMCStreamer);

}

// DataLayout --> Big-endian, 32-bit pointer/ABI/alignment
// The stack is always 8 byte aligned
// On function prologue, the stack is created by decrementing
// its pointer. Once decremented, all references are done with positive
// offset from the stack/frame pointer, using StackGrowsUp enables
// an easier handling.
MBlazeTargetMachine::
MBlazeTargetMachine(const Target &T, const std::string &TT,
                    const std::string &FS):
  LLVMTargetMachine(T, TT),
  Subtarget(TT, FS),
  DataLayout("E-p:32:32:32-i8:8:8-i16:16:16"),
  InstrInfo(*this),
  FrameLowering(Subtarget),
  TLInfo(*this), TSInfo(*this), ELFWriterInfo(*this),
  InstrItins(Subtarget.getInstrItineraryData()) {
  if (getRelocationModel() == Reloc::Default) {
      setRelocationModel(Reloc::Static);
  }

  if (getCodeModel() == CodeModel::Default)
    setCodeModel(CodeModel::Small);
}

// Install an instruction selector pass using
// the ISelDag to gen MBlaze code.
bool MBlazeTargetMachine::addInstSelector(PassManagerBase &PM,
                                          CodeGenOpt::Level OptLevel) {
  PM.add(createMBlazeISelDag(*this));
  return false;
}

// Implemented by targets that want to run passes immediately before
// machine code is emitted. return true if -print-machineinstrs should
// print out the code after the passes.
bool MBlazeTargetMachine::addPreEmitPass(PassManagerBase &PM,
                                         CodeGenOpt::Level OptLevel) {
  PM.add(createMBlazeDelaySlotFillerPass(*this));
  return true;
}