third_party/llvm-7.0/llvm/tools/llvm-mca/SummaryView.cpp

//===--------------------- SummaryView.cpp -------------------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
/// \file
///
/// This file implements the functionalities used by the SummaryView to print
/// the report information.
///
//===----------------------------------------------------------------------===//

#include "SummaryView.h"
#include "Support.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/Support/Format.h"

namespace mca {

#define DEBUG_TYPE "llvm-mca"

using namespace llvm;

SummaryView::SummaryView(const llvm::MCSchedModel &Model, const SourceMgr &S,
                         unsigned Width)
    : SM(Model), Source(S), DispatchWidth(Width), TotalCycles(0),
      NumMicroOps(0), ProcResourceUsage(Model.getNumProcResourceKinds(), 0),
      ProcResourceMasks(Model.getNumProcResourceKinds(), 0) {
  computeProcResourceMasks(SM, ProcResourceMasks);
}

void SummaryView::onEvent(const HWInstructionEvent &Event) {
  // We are only interested in the "instruction dispatched" events generated by
  // the dispatch stage for instructions that are part of iteration #0.
  if (Event.Type != HWInstructionEvent::Dispatched)
    return;

  if (Event.IR.getSourceIndex() >= Source.size())
    return;

  // Update the cumulative number of resource cycles based on the processor
  // resource usage information available from the instruction descriptor. We
  // need to compute the cumulative number of resource cycles for every
  // processor resource which is consumed by an instruction of the block.
  const Instruction &Inst = *Event.IR.getInstruction();
  const InstrDesc &Desc = Inst.getDesc();
  NumMicroOps += Desc.NumMicroOps;
  for (const std::pair<uint64_t, const ResourceUsage> &RU : Desc.Resources) {
    if (RU.second.size()) {
      const auto It = find(ProcResourceMasks, RU.first);
      assert(It != ProcResourceMasks.end() &&
             "Invalid processor resource mask!");
      ProcResourceUsage[std::distance(ProcResourceMasks.begin(), It)] +=
          RU.second.size();
    }
  }
}

void SummaryView::printView(raw_ostream &OS) const {
  unsigned Iterations = Source.getNumIterations();
  unsigned Instructions = Source.size();
  unsigned TotalInstructions = Instructions * Iterations;
  double IPC = (double)TotalInstructions / TotalCycles;
  double BlockRThroughput = computeBlockRThroughput(
      SM, DispatchWidth, NumMicroOps, ProcResourceUsage);

  std::string Buffer;
  raw_string_ostream TempStream(Buffer);
  TempStream << "Iterations:        " << Iterations;
  TempStream << "\nInstructions:      " << TotalInstructions;
  TempStream << "\nTotal Cycles:      " << TotalCycles;
  TempStream << "\nDispatch Width:    " << DispatchWidth;
  TempStream << "\nIPC:               " << format("%.2f", IPC);

  // Round to the block reciprocal throughput to the nearest tenth.
  TempStream << "\nBlock RThroughput: "
             << format("%.1f", floor((BlockRThroughput * 10) + 0.5) / 10)
             << '\n';
  TempStream.flush();
  OS << Buffer;
}
} // namespace mca.