1//===--------------------- SummaryView.h ---------------------*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8/// \file
9///
10/// This file implements the summary view.
11///
12/// The goal of the summary view is to give a very quick overview of the
13/// performance throughput. Below is an example of summary view:
14///
15///
16/// Iterations:        300
17/// Instructions:      900
18/// Total Cycles:      610
19/// Dispatch Width:    2
20/// IPC:               1.48
21/// Block RThroughput: 2.0
22///
23/// The summary view collects a few performance numbers. The two main
24/// performance indicators are 'Total Cycles' and IPC (Instructions Per Cycle).
25///
26//===----------------------------------------------------------------------===//
27
28#ifndef LLVM_TOOLS_LLVM_MCA_SUMMARYVIEW_H
29#define LLVM_TOOLS_LLVM_MCA_SUMMARYVIEW_H
30
31#include "Views/View.h"
32#include "llvm/ADT/DenseMap.h"
33#include "llvm/MC/MCSchedule.h"
34#include "llvm/Support/raw_ostream.h"
35
36namespace llvm {
37namespace mca {
38
39/// A view that collects and prints a few performance numbers.
40class SummaryView : public View {
41  const llvm::MCSchedModel &SM;
42  llvm::ArrayRef<llvm::MCInst> Source;
43  const unsigned DispatchWidth;
44  unsigned LastInstructionIdx;
45  unsigned TotalCycles;
46  // The total number of micro opcodes contributed by a block of instructions.
47  unsigned NumMicroOps;
48
49  // For each processor resource, this vector stores the cumulative number of
50  // resource cycles consumed by the analyzed code block.
51  llvm::SmallVector<unsigned, 8> ProcResourceUsage;
52
53  // Each processor resource is associated with a so-called processor resource
54  // mask. This vector allows to correlate processor resource IDs with processor
55  // resource masks. There is exactly one element per each processor resource
56  // declared by the scheduling model.
57  llvm::SmallVector<uint64_t, 8> ProcResourceMasks;
58
59  // Used to map resource indices to actual processor resource IDs.
60  llvm::SmallVector<unsigned, 8> ResIdx2ProcResID;
61
62  // Compute the reciprocal throughput for the analyzed code block.
63  // The reciprocal block throughput is computed as the MAX between:
64  //   - NumMicroOps / DispatchWidth
65  //   - Total Resource Cycles / #Units   (for every resource consumed).
66  double getBlockRThroughput() const;
67
68public:
69  SummaryView(const llvm::MCSchedModel &Model, llvm::ArrayRef<llvm::MCInst> S,
70              unsigned Width);
71
72  void onCycleEnd() override { ++TotalCycles; }
73  void onEvent(const HWInstructionEvent &Event) override;
74  void printView(llvm::raw_ostream &OS) const override;
75};
76
77} // namespace mca
78} // namespace llvm
79
80#endif
81