1//===--------------------- ResourcePressureView.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 define class ResourcePressureView.
11/// Class ResourcePressureView observes hardware events generated by
12/// the Pipeline object and collects statistics related to resource usage at
13/// instruction granularity.
14/// Resource pressure information is then printed out to a stream in the
15/// form of a table like the one from the example below:
16///
17/// Resources:
18/// [0] - JALU0
19/// [1] - JALU1
20/// [2] - JDiv
21/// [3] - JFPM
22/// [4] - JFPU0
23/// [5] - JFPU1
24/// [6] - JLAGU
25/// [7] - JSAGU
26/// [8] - JSTC
27/// [9] - JVIMUL
28///
29/// Resource pressure per iteration:
30/// [0] [1] [2] [3] [4] [5] [6] [7] [8] [9]
31/// 0.00 0.00 0.00 0.00 2.00 2.00 0.00 0.00 0.00 0.00
32///
33/// Resource pressure by instruction:
34/// [0] [1] [2] [3] [4] [5] [6] [7] [8] [9] Instructions:
35/// - - - - - 1.00 - - - - vpermilpd $1, %xmm0,
36/// %xmm1
37/// - - - - 1.00 - - - - - vaddps %xmm0, %xmm1,
38/// %xmm2
39/// - - - - - 1.00 - - - - vmovshdup %xmm2, %xmm3
40/// - - - - 1.00 - - - - - vaddss %xmm2, %xmm3,
41/// %xmm4
42///
43/// In this example, we have AVX code executed on AMD Jaguar (btver2).
44/// Both shuffles and vector floating point add operations on XMM registers have
45/// a reciprocal throughput of 1cy.
46/// Each add is issued to pipeline JFPU0, while each shuffle is issued to
47/// pipeline JFPU1. The overall pressure per iteration is reported by two
48/// tables: the first smaller table is the resource pressure per iteration;
49/// the second table reports resource pressure per instruction. Values are the
50/// average resource cycles consumed by an instruction.
51/// Every vector add from the example uses resource JFPU0 for an average of 1cy
52/// per iteration. Consequently, the resource pressure on JFPU0 is of 2cy per
53/// iteration.
54///
55//===----------------------------------------------------------------------===//
56
57#ifndef LLVM_TOOLS_LLVM_MCA_RESOURCEPRESSUREVIEW_H
58#define LLVM_TOOLS_LLVM_MCA_RESOURCEPRESSUREVIEW_H
59
60#include "Views/InstructionView.h"
61#include "llvm/ADT/ArrayRef.h"
62#include "llvm/ADT/DenseMap.h"
63#include "llvm/MC/MCInst.h"
64#include "llvm/MC/MCInstPrinter.h"
65#include "llvm/MC/MCSubtargetInfo.h"
66#include "llvm/Support/JSON.h"
67
68namespace llvm {
69namespace mca {
70
71/// This class collects resource pressure statistics and it is able to print
72/// out all the collected information as a table to an output stream.
73class ResourcePressureView : public InstructionView {
74 unsigned LastInstructionIdx;
75
76 // Map to quickly obtain the ResourceUsage column index from a processor
77 // resource ID.
78 llvm::DenseMap<unsigned, unsigned> Resource2VecIndex;
79
80 struct ResourceReleaseAtCycles {
81 unsigned ResourceIdx;
82 ReleaseAtCycles Cycles;
83 };
84 using InstResourceUsage = std::vector<ResourceReleaseAtCycles>;
85 std::vector<InstResourceUsage> ResourceUsage;
86 InstResourceUsage CommonResourceUsage;
87 unsigned NumResourceUnits;
88
89 void printResourcePressurePerIter(llvm::raw_ostream &OS) const;
90 void printResourcePressurePerInst(llvm::raw_ostream &OS) const;
91
92public:
93 ResourcePressureView(const llvm::MCSubtargetInfo &sti,
94 llvm::MCInstPrinter &Printer,
95 llvm::ArrayRef<llvm::MCInst> S);
96
97 void onEvent(const HWInstructionEvent &Event) override;
98 void printView(llvm::raw_ostream &OS) const override {
99 printResourcePressurePerIter(OS);
100 printResourcePressurePerInst(OS);
101 }
102 StringRef getNameAsString() const override { return "ResourcePressureView"; }
103 json::Value toJSON() const override;
104};
105} // namespace mca
106} // namespace llvm
107
108#endif
109