//===-- RISCVTargetMachine.cpp - Define TargetMachine for RISCV -----------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// Implements the info about RISCV target spec.
//
//===----------------------------------------------------------------------===//

#include "RISCV.h"
#include "RISCVTargetMachine.h"
#include "RISCVTargetObjectFile.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/CodeGen/Passes.h"
#include "llvm/CodeGen/TargetLoweringObjectFileImpl.h"
#include "llvm/CodeGen/TargetPassConfig.h"
#include "llvm/IR/LegacyPassManager.h"
#include "llvm/Support/FormattedStream.h"
#include "llvm/Support/TargetRegistry.h"
#include "llvm/Target/TargetOptions.h"
using namespace llvm;

extern "C" void LLVMInitializeRISCVTarget() {
  RegisterTargetMachine<RISCVTargetMachine> X(getTheRISCV32Target());
  RegisterTargetMachine<RISCVTargetMachine> Y(getTheRISCV64Target());
  auto PR = PassRegistry::getPassRegistry();
  initializeRISCVExpandPseudoPass(*PR);
}

static std::string computeDataLayout(const Triple &TT) {
  if (TT.isArch64Bit()) {
    return "e-m:e-p:64:64-i64:64-i128:128-n64-S128";
  } else {
    assert(TT.isArch32Bit() && "only RV32 and RV64 are currently supported");
    return "e-m:e-p:32:32-i64:64-n32-S128";
  }
}

static Reloc::Model getEffectiveRelocModel(const Triple &TT,
                                           Optional<Reloc::Model> RM) {
  if (!RM.hasValue())
    return Reloc::Static;
  return *RM;
}

RISCVTargetMachine::RISCVTargetMachine(const Target &T, const Triple &TT,
                                       StringRef CPU, StringRef FS,
                                       const TargetOptions &Options,
                                       Optional<Reloc::Model> RM,
                                       Optional<CodeModel::Model> CM,
                                       CodeGenOpt::Level OL, bool JIT)
    : LLVMTargetMachine(T, computeDataLayout(TT), TT, CPU, FS, Options,
                        getEffectiveRelocModel(TT, RM),
                        getEffectiveCodeModel(CM, CodeModel::Small), OL),
      TLOF(make_unique<RISCVELFTargetObjectFile>()),
      Subtarget(TT, CPU, FS, *this) {
  initAsmInfo();
}

namespace {
class RISCVPassConfig : public TargetPassConfig {
public:
  RISCVPassConfig(RISCVTargetMachine &TM, PassManagerBase &PM)
      : TargetPassConfig(TM, PM) {}

  RISCVTargetMachine &getRISCVTargetMachine() const {
    return getTM<RISCVTargetMachine>();
  }

  void addIRPasses() override;
  bool addInstSelector() override;
  void addPreEmitPass() override;
  void addPreEmitPass2() override;
  void addPreRegAlloc() override;
};
}

TargetPassConfig *RISCVTargetMachine::createPassConfig(PassManagerBase &PM) {
  return new RISCVPassConfig(*this, PM);
}

void RISCVPassConfig::addIRPasses() {
  addPass(createAtomicExpandPass());
  TargetPassConfig::addIRPasses();
}

bool RISCVPassConfig::addInstSelector() {
  addPass(createRISCVISelDag(getRISCVTargetMachine()));

  return false;
}

void RISCVPassConfig::addPreEmitPass() { addPass(&BranchRelaxationPassID); }

void RISCVPassConfig::addPreEmitPass2() {
  // Schedule the expansion of AMOs at the last possible moment, avoiding the
  // possibility for other passes to break the requirements for forward
  // progress in the LR/SC block.
  addPass(createRISCVExpandPseudoPass());
}

void RISCVPassConfig::addPreRegAlloc() {
  addPass(createRISCVMergeBaseOffsetOptPass());
}