lib/Target/ARM/ARMTargetMachine.cpp

//===-- ARMTargetMachine.cpp - Define TargetMachine for ARM ---------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
//
//===----------------------------------------------------------------------===//

#include "ARMTargetMachine.h"
#include "ARMMCAsmInfo.h"
#include "ARMFrameInfo.h"
#include "ARM.h"
#include "llvm/PassManager.h"
#include "llvm/CodeGen/Passes.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/FormattedStream.h"
#include "llvm/Target/TargetOptions.h"
#include "llvm/Target/TargetRegistry.h"
using namespace llvm;

static cl::opt<bool>
EarlyITBlockFormation("thumb2-early-it-blocks", cl::Hidden,
  cl::desc("Form IT blocks early before register allocation"),
  cl::init(false));

static cl::opt<bool>
EarlyIfConvert("arm-early-if-convert", cl::Hidden,
  cl::desc("Run if-conversion before post-ra scheduling"),
  cl::init(false));

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


extern "C" void LLVMInitializeARMTarget() {
  // Register the target.
  RegisterTargetMachine<ARMTargetMachine> X(TheARMTarget);
  RegisterTargetMachine<ThumbTargetMachine> Y(TheThumbTarget);

  // Register the target asm info.
  RegisterAsmInfoFn A(TheARMTarget, createMCAsmInfo);
  RegisterAsmInfoFn B(TheThumbTarget, createMCAsmInfo);
}

/// TargetMachine ctor - Create an ARM architecture model.
///
ARMBaseTargetMachine::ARMBaseTargetMachine(const Target &T,
                                           const std::string &TT,
                                           const std::string &FS,
                                           bool isThumb)
  : LLVMTargetMachine(T, TT),
    Subtarget(TT, FS, isThumb),
    FrameInfo(Subtarget),
    JITInfo(),
    InstrItins(Subtarget.getInstrItineraryData()) {
  DefRelocModel = getRelocationModel();
}

ARMTargetMachine::ARMTargetMachine(const Target &T, const std::string &TT,
                                   const std::string &FS)
  : ARMBaseTargetMachine(T, TT, FS, false), InstrInfo(Subtarget),
    DataLayout(Subtarget.isAPCS_ABI() ?
               std::string("e-p:32:32-f64:32:32-i64:32:32-n32") :
               std::string("e-p:32:32-f64:64:64-i64:64:64-n32")),
    TLInfo(*this),
    TSInfo(*this) {
}

ThumbTargetMachine::ThumbTargetMachine(const Target &T, const std::string &TT,
                                       const std::string &FS)
  : ARMBaseTargetMachine(T, TT, FS, true),
    InstrInfo(Subtarget.hasThumb2()
              ? ((ARMBaseInstrInfo*)new Thumb2InstrInfo(Subtarget))
              : ((ARMBaseInstrInfo*)new Thumb1InstrInfo(Subtarget))),
    DataLayout(Subtarget.isAPCS_ABI() ?
               std::string("e-p:32:32-f64:32:32-i64:32:32-"
                           "i16:16:32-i8:8:32-i1:8:32-a:0:32-n32") :
               std::string("e-p:32:32-f64:64:64-i64:64:64-"
                           "i16:16:32-i8:8:32-i1:8:32-a:0:32-n32")),
    TLInfo(*this),
    TSInfo(*this) {
}



// Pass Pipeline Configuration
bool ARMBaseTargetMachine::addInstSelector(PassManagerBase &PM,
                                           CodeGenOpt::Level OptLevel) {
  PM.add(createARMISelDag(*this, OptLevel));
  return false;
}

bool ARMBaseTargetMachine::addPreRegAlloc(PassManagerBase &PM,
                                          CodeGenOpt::Level OptLevel) {
  if (Subtarget.hasNEON())
    PM.add(createNEONPreAllocPass());

  // FIXME: temporarily disabling load / store optimization pass for Thumb1.
  if (OptLevel != CodeGenOpt::None && !Subtarget.isThumb1Only())
    PM.add(createARMLoadStoreOptimizationPass(true));

  if (OptLevel != CodeGenOpt::None && Subtarget.isThumb2() &&
      EarlyITBlockFormation)
    PM.add(createThumb2ITBlockPass(true));
  return true;
}

bool ARMBaseTargetMachine::addPreSched2(PassManagerBase &PM,
                                        CodeGenOpt::Level OptLevel) {
  // FIXME: temporarily disabling load / store optimization pass for Thumb1.
  if (OptLevel != CodeGenOpt::None) {
    if (!Subtarget.isThumb1Only())
      PM.add(createARMLoadStoreOptimizationPass());
    if (Subtarget.hasNEON())
      PM.add(createNEONMoveFixPass());
  }

  // Expand some pseudo instructions into multiple instructions to allow
  // proper scheduling.
  PM.add(createARMExpandPseudoPass());

  if (EarlyIfConvert && OptLevel != CodeGenOpt::None) {
    if (!Subtarget.isThumb1Only()) 
      PM.add(createIfConverterPass());
  }

  return true;
}

bool ARMBaseTargetMachine::addPreEmitPass(PassManagerBase &PM,
                                          CodeGenOpt::Level OptLevel) {
  if (!EarlyIfConvert && OptLevel != CodeGenOpt::None) {
    if (!Subtarget.isThumb1Only())
      PM.add(createIfConverterPass());
  }

  if (Subtarget.isThumb2()) {
    PM.add(createThumb2ITBlockPass());
    PM.add(createThumb2SizeReductionPass());
  }

  PM.add(createARMConstantIslandPass());
  return true;
}

bool ARMBaseTargetMachine::addCodeEmitter(PassManagerBase &PM,
                                          CodeGenOpt::Level OptLevel,
                                          JITCodeEmitter &JCE) {
  // FIXME: Move this to TargetJITInfo!
  if (DefRelocModel == Reloc::Default)
    setRelocationModel(Reloc::Static);

  // Machine code emitter pass for ARM.
  PM.add(createARMJITCodeEmitterPass(*this, JCE));
  return false;
}