Context.cpp

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//===---------------------------- Context.cpp -------------------*- C++ -*-===//
//
// 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
//
//===----------------------------------------------------------------------===//
/// \file
///
/// This file defines a class for holding ownership of various simulated
/// hardware units.  A Context also provides a utility routine for constructing
/// a default out-of-order pipeline with fetch, dispatch, execute, and retire
/// stages.
///
//===----------------------------------------------------------------------===//
 
#include "llvm/MCA/Context.h"
#include "llvm/MCA/HardwareUnits/RegisterFile.h"
#include "llvm/MCA/HardwareUnits/RetireControlUnit.h"
#include "llvm/MCA/HardwareUnits/Scheduler.h"
#include "llvm/MCA/Stages/DispatchStage.h"
#include "llvm/MCA/Stages/EntryStage.h"
#include "llvm/MCA/Stages/ExecuteStage.h"
#include "llvm/MCA/Stages/InOrderIssueStage.h"
#include "llvm/MCA/Stages/MicroOpQueueStage.h"
#include "llvm/MCA/Stages/RetireStage.h"
 
namespace llvm {
namespace mca {
 
std::unique_ptr<Pipeline>
Context::createDefaultPipeline(const PipelineOptions &Opts, SourceMgr &SrcMgr,
                               CustomBehaviour &CB) {
  const MCSchedModel &SM = STI.getSchedModel();
 
  if (!SM.isOutOfOrder())
    return createInOrderPipeline(Opts, SrcMgr, CB);
 
  // Create the hardware units defining the backend.
  auto RCU = std::make_unique<RetireControlUnit>(SM);
  auto PRF = std::make_unique<RegisterFile>(SM, MRI, Opts.RegisterFileSize);
  auto LSU = std::make_unique<LSUnit>(SM, Opts.LoadQueueSize,
                                      Opts.StoreQueueSize, Opts.AssumeNoAlias);
  auto HWS =
      std::make_unique<Scheduler>(SM, *LSU, Opts.ReservationStationScaleFactor);
 
  // Create the pipeline stages.
  auto Fetch = std::make_unique<EntryStage>(SrcMgr);
  auto Dispatch =
      std::make_unique<DispatchStage>(STI, MRI, Opts.DispatchWidth, *RCU, *PRF);
  auto Execute =
      std::make_unique<ExecuteStage>(*HWS, Opts.EnableBottleneckAnalysis);
  auto Retire = std::make_unique<RetireStage>(*RCU, *PRF, *LSU);
 
  // Pass the ownership of all the hardware units to this Context.
  addHardwareUnit(std::move(RCU));
  addHardwareUnit(std::move(PRF));
  addHardwareUnit(std::move(LSU));
  addHardwareUnit(std::move(HWS));
 
  // Build the pipeline.
  auto StagePipeline = std::make_unique<Pipeline>();
  StagePipeline->appendStage(std::move(Fetch));
  if (Opts.MicroOpQueueSize)
    StagePipeline->appendStage(std::make_unique<MicroOpQueueStage>(
        Opts.MicroOpQueueSize, Opts.DecodersThroughput));
  StagePipeline->appendStage(std::move(Dispatch));
  StagePipeline->appendStage(std::move(Execute));
  StagePipeline->appendStage(std::move(Retire));
  return StagePipeline;
}
 
std::unique_ptr<Pipeline>
Context::createInOrderPipeline(const PipelineOptions &Opts, SourceMgr &SrcMgr,
                               CustomBehaviour &CB) {
  const MCSchedModel &SM = STI.getSchedModel();
  auto PRF = std::make_unique<RegisterFile>(SM, MRI, Opts.RegisterFileSize);
  auto LSU = std::make_unique<LSUnit>(SM, Opts.LoadQueueSize,
                                      Opts.StoreQueueSize, Opts.AssumeNoAlias);
 
  // Create the pipeline stages.
  auto Entry = std::make_unique<EntryStage>(SrcMgr);
  auto InOrderIssue = std::make_unique<InOrderIssueStage>(
      STI, *PRF, CB, *LSU, Opts.ReservationStationScaleFactor);
  auto StagePipeline = std::make_unique<Pipeline>();
 
  // Pass the ownership of all the hardware units to this Context.
  addHardwareUnit(std::move(PRF));
  addHardwareUnit(std::move(LSU));
 
  // Build the pipeline.
  StagePipeline->appendStage(std::move(Entry));
  StagePipeline->appendStage(std::move(InOrderIssue));
  return StagePipeline;
}
 
} // namespace mca
} // namespace llvm