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1 //===--------------------- RegisterFileStatistics.cpp -----------*- 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 implements the RegisterFileStatistics interface.
12 ///
13 //===----------------------------------------------------------------------===//
14 
15 #include "RegisterFileStatistics.h"
16 #include "llvm/Support/Format.h"
17 
18 using namespace llvm;
19 
20 namespace mca {
21 
initializeRegisterFileInfo()22 void RegisterFileStatistics::initializeRegisterFileInfo() {
23   const MCSchedModel &SM = STI.getSchedModel();
24   RegisterFileUsage Empty = {0, 0, 0};
25   if (!SM.hasExtraProcessorInfo()) {
26     // Assume a single register file.
27     RegisterFiles.emplace_back(Empty);
28     return;
29   }
30 
31   // Initialize a RegisterFileUsage for every user defined register file, plus
32   // the default register file which is always at index #0.
33   const MCExtraProcessorInfo &PI = SM.getExtraProcessorInfo();
34   // There is always an "InvalidRegisterFile" entry in tablegen. That entry can
35   // be skipped. If there are no user defined register files, then reserve a
36   // single entry for the default register file at index #0.
37   unsigned NumRegFiles = std::max(PI.NumRegisterFiles, 1U);
38   RegisterFiles.resize(NumRegFiles);
39   std::fill(RegisterFiles.begin(), RegisterFiles.end(), Empty);
40 }
41 
onEvent(const HWInstructionEvent & Event)42 void RegisterFileStatistics::onEvent(const HWInstructionEvent &Event) {
43   switch (Event.Type) {
44   default:
45     break;
46   case HWInstructionEvent::Retired: {
47     const auto &RE = static_cast<const HWInstructionRetiredEvent &>(Event);
48     for (unsigned I = 0, E = RegisterFiles.size(); I < E; ++I)
49       RegisterFiles[I].CurrentlyUsedMappings -= RE.FreedPhysRegs[I];
50     break;
51   }
52   case HWInstructionEvent::Dispatched: {
53     const auto &DE = static_cast<const HWInstructionDispatchedEvent &>(Event);
54     for (unsigned I = 0, E = RegisterFiles.size(); I < E; ++I) {
55       RegisterFileUsage &RFU = RegisterFiles[I];
56       unsigned NumUsedPhysRegs = DE.UsedPhysRegs[I];
57       RFU.CurrentlyUsedMappings += NumUsedPhysRegs;
58       RFU.TotalMappings += NumUsedPhysRegs;
59       RFU.MaxUsedMappings =
60           std::max(RFU.MaxUsedMappings, RFU.CurrentlyUsedMappings);
61     }
62   }
63   }
64 }
65 
printView(raw_ostream & OS) const66 void RegisterFileStatistics::printView(raw_ostream &OS) const {
67   std::string Buffer;
68   raw_string_ostream TempStream(Buffer);
69 
70   TempStream << "\n\nRegister File statistics:";
71   const RegisterFileUsage &GlobalUsage = RegisterFiles[0];
72   TempStream << "\nTotal number of mappings created:    "
73              << GlobalUsage.TotalMappings;
74   TempStream << "\nMax number of mappings used:         "
75              << GlobalUsage.MaxUsedMappings << '\n';
76 
77   for (unsigned I = 1, E = RegisterFiles.size(); I < E; ++I) {
78     const RegisterFileUsage &RFU = RegisterFiles[I];
79     // Obtain the register file descriptor from the scheduling model.
80     assert(STI.getSchedModel().hasExtraProcessorInfo() &&
81            "Unable to find register file info!");
82     const MCExtraProcessorInfo &PI =
83         STI.getSchedModel().getExtraProcessorInfo();
84     assert(I <= PI.NumRegisterFiles && "Unexpected register file index!");
85     const MCRegisterFileDesc &RFDesc = PI.RegisterFiles[I];
86     // Skip invalid register files.
87     if (!RFDesc.NumPhysRegs)
88       continue;
89 
90     TempStream << "\n*  Register File #" << I;
91     TempStream << " -- " << StringRef(RFDesc.Name) << ':';
92     TempStream << "\n   Number of physical registers:     ";
93     if (!RFDesc.NumPhysRegs)
94       TempStream << "unbounded";
95     else
96       TempStream << RFDesc.NumPhysRegs;
97     TempStream << "\n   Total number of mappings created: "
98                << RFU.TotalMappings;
99     TempStream << "\n   Max number of mappings used:      "
100                << RFU.MaxUsedMappings << '\n';
101   }
102 
103   TempStream.flush();
104   OS << Buffer;
105 }
106 
107 } // namespace mca
108