AVRTargetMachine.cpp

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//===-- AVRTargetMachine.cpp - Define TargetMachine for AVR ---------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
//
// This file defines the AVR specific subclass of TargetMachine.
//
//===----------------------------------------------------------------------===//
 
#include "AVRTargetMachine.h"
 
#include "llvm/CodeGen/Passes.h"
#include "llvm/CodeGen/TargetPassConfig.h"
#include "llvm/IR/LegacyPassManager.h"
#include "llvm/IR/Module.h"
#include "llvm/Support/TargetRegistry.h"
 
#include "AVR.h"
#include "AVRTargetObjectFile.h"
#include "MCTargetDesc/AVRMCTargetDesc.h"
#include "TargetInfo/AVRTargetInfo.h"
 
namespace llvm {
 
static const char *AVRDataLayout =
    "e-P1-p:16:8-i8:8-i16:8-i32:8-i64:8-f32:8-f64:8-n8-a:8";
 
/// Processes a CPU name.
static StringRef getCPU(StringRef CPU) {
  if (CPU.empty() || CPU == "generic") {
    return "avr2";
  }
 
  return CPU;
}
 
static Reloc::Model getEffectiveRelocModel(Optional<Reloc::Model> RM) {
  return RM.getValueOr(Reloc::Static);
}
 
AVRTargetMachine::AVRTargetMachine(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, AVRDataLayout, TT, getCPU(CPU), FS, Options,
                        getEffectiveRelocModel(RM),
                        getEffectiveCodeModel(CM, CodeModel::Small), OL),
      SubTarget(TT, std::string(getCPU(CPU)), std::string(FS), *this) {
  this->TLOF = std::make_unique<AVRTargetObjectFile>();
  initAsmInfo();
}
 
namespace {
/// AVR Code Generator Pass Configuration Options.
class AVRPassConfig : public TargetPassConfig {
public:
  AVRPassConfig(AVRTargetMachine &TM, PassManagerBase &PM)
      : TargetPassConfig(TM, PM) {}
 
  AVRTargetMachine &getAVRTargetMachine() const {
    return getTM<AVRTargetMachine>();
  }
 
  void addIRPasses() override;
  bool addInstSelector() override;
  void addPreSched2() override;
  void addPreEmitPass() override;
  void addPreRegAlloc() override;
};
} // namespace
 
TargetPassConfig *AVRTargetMachine::createPassConfig(PassManagerBase &PM) {
  return new AVRPassConfig(*this, PM);
}
 
void AVRPassConfig::addIRPasses() {
  // Expand instructions like
  //   %result = shl i32 %n, %amount
  // to a loop so that library calls are avoided.
  addPass(createAVRShiftExpandPass());
 
  TargetPassConfig::addIRPasses();
}
 
extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializeAVRTarget() {
  // Register the target.
  RegisterTargetMachine<AVRTargetMachine> X(getTheAVRTarget());
 
  auto &PR = *PassRegistry::getPassRegistry();
  initializeAVRExpandPseudoPass(PR);
  initializeAVRRelaxMemPass(PR);
  initializeAVRShiftExpandPass(PR);
}
 
const AVRSubtarget *AVRTargetMachine::getSubtargetImpl() const {
  return &SubTarget;
}
 
const AVRSubtarget *AVRTargetMachine::getSubtargetImpl(const Function &) const {
  return &SubTarget;
}
 
//===----------------------------------------------------------------------===//
// Pass Pipeline Configuration
//===----------------------------------------------------------------------===//
 
bool AVRPassConfig::addInstSelector() {
  // Install an instruction selector.
  addPass(createAVRISelDag(getAVRTargetMachine(), getOptLevel()));
  // Create the frame analyzer pass used by the PEI pass.
  addPass(createAVRFrameAnalyzerPass());
 
  return false;
}
 
void AVRPassConfig::addPreRegAlloc() {
  // Create the dynalloc SP save/restore pass to handle variable sized allocas.
  addPass(createAVRDynAllocaSRPass());
}
 
void AVRPassConfig::addPreSched2() {
  addPass(createAVRRelaxMemPass());
  addPass(createAVRExpandPseudoPass());
}
 
void AVRPassConfig::addPreEmitPass() {
  // Must run branch selection immediately preceding the asm printer.
  addPass(&BranchRelaxationPassID);
}
 
} // end of namespace llvm