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1 //===--------------------- ResourcePressureView.h ---------------*- C++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 /// \file
10 ///
11 /// This file define class ResourcePressureView.
12 /// Class ResourcePressureView observes hardware events generated by
13 /// the Pipeline object and collects statistics related to resource usage at
14 /// instruction granularity.
15 /// Resource pressure information is then printed out to a stream in the
16 /// form of a table like the one from the example below:
17 ///
18 /// Resources:
19 /// [0] - JALU0
20 /// [1] - JALU1
21 /// [2] - JDiv
22 /// [3] - JFPM
23 /// [4] - JFPU0
24 /// [5] - JFPU1
25 /// [6] - JLAGU
26 /// [7] - JSAGU
27 /// [8] - JSTC
28 /// [9] - JVIMUL
29 ///
30 /// Resource pressure per iteration:
31 /// [0]    [1]    [2]    [3]    [4]    [5]    [6]    [7]    [8]    [9]
32 /// 0.00   0.00   0.00   0.00   2.00   2.00   0.00   0.00   0.00   0.00
33 ///
34 /// Resource pressure by instruction:
35 /// [0]  [1]  [2]  [3]  [4]  [5]  [6]  [7]  [8]  [9]  Instructions:
36 ///  -    -    -    -    -   1.00  -    -    -    -   vpermilpd  $1,    %xmm0,
37 ///  %xmm1
38 ///  -    -    -    -   1.00  -    -    -    -    -   vaddps     %xmm0, %xmm1,
39 ///  %xmm2
40 ///  -    -    -    -    -   1.00  -    -    -    -   vmovshdup  %xmm2, %xmm3
41 ///  -    -    -    -   1.00  -    -    -    -    -   vaddss     %xmm2, %xmm3,
42 ///  %xmm4
43 ///
44 /// In this example, we have AVX code executed on AMD Jaguar (btver2).
45 /// Both shuffles and vector floating point add operations on XMM registers have
46 /// a reciprocal throughput of 1cy.
47 /// Each add is issued to pipeline JFPU0, while each shuffle is issued to
48 /// pipeline JFPU1. The overall pressure per iteration is reported by two
49 /// tables: the first smaller table is the resource pressure per iteration;
50 /// the second table reports resource pressure per instruction. Values are the
51 /// average resource cycles consumed by an instruction.
52 /// Every vector add from the example uses resource JFPU0 for an average of 1cy
53 /// per iteration. Consequently, the resource pressure on JFPU0 is of 2cy per
54 /// iteration.
55 ///
56 //===----------------------------------------------------------------------===//
57 
58 #ifndef LLVM_TOOLS_LLVM_MCA_RESOURCEPRESSUREVIEW_H
59 #define LLVM_TOOLS_LLVM_MCA_RESOURCEPRESSUREVIEW_H
60 
61 #include "SourceMgr.h"
62 #include "View.h"
63 #include "llvm/ADT/DenseMap.h"
64 #include "llvm/MC/MCInstPrinter.h"
65 #include "llvm/MC/MCSubtargetInfo.h"
66 #include <map>
67 
68 namespace mca {
69 
70 /// This class collects resource pressure statistics and it is able to print
71 /// out all the collected information as a table to an output stream.
72 class ResourcePressureView : public View {
73   const llvm::MCSubtargetInfo &STI;
74   llvm::MCInstPrinter &MCIP;
75   const SourceMgr &Source;
76 
77   // Map to quickly obtain the ResourceUsage column index from a processor
78   // resource ID.
79   llvm::DenseMap<unsigned, unsigned> Resource2VecIndex;
80 
81   // Table of resources used by instructions.
82   std::vector<double> ResourceUsage;
83   unsigned NumResourceUnits;
84 
85   const llvm::MCInst &GetMCInstFromIndex(unsigned Index) const;
86   void printResourcePressurePerIteration(llvm::raw_ostream &OS,
87                                          unsigned Executions) const;
88   void printResourcePressurePerInstruction(llvm::raw_ostream &OS,
89                                            unsigned Executions) const;
90   void initialize();
91 
92 public:
ResourcePressureView(const llvm::MCSubtargetInfo & sti,llvm::MCInstPrinter & Printer,const SourceMgr & SM)93   ResourcePressureView(const llvm::MCSubtargetInfo &sti,
94                        llvm::MCInstPrinter &Printer, const SourceMgr &SM)
95       : STI(sti), MCIP(Printer), Source(SM) {
96     initialize();
97   }
98 
99   void onEvent(const HWInstructionEvent &Event) override;
100 
printView(llvm::raw_ostream & OS)101   void printView(llvm::raw_ostream &OS) const override {
102     unsigned Executions = Source.getNumIterations();
103     printResourcePressurePerIteration(OS, Executions);
104     printResourcePressurePerInstruction(OS, Executions);
105   }
106 };
107 } // namespace mca
108 
109 #endif
110