lib/ProfileData/ProfileSummaryBuilder.cpp

   1 //=-- ProfilesummaryBuilder.cpp - Profile summary computation ---------------=//
   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 //
   9 // This file contains support for computing profile summary data.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "llvm/IR/Attributes.h"
  14 #include "llvm/IR/Function.h"
  15 #include "llvm/IR/Metadata.h"
  16 #include "llvm/IR/Type.h"
  17 #include "llvm/ProfileData/InstrProf.h"
  18 #include "llvm/ProfileData/ProfileCommon.h"
  19 #include "llvm/ProfileData/SampleProf.h"
  20 #include "llvm/Support/Casting.h"
  21
  22 using namespace llvm;
  23
  24 // A set of cutoff values. Each value, when divided by ProfileSummary::Scale
  25 // (which is 1000000) is a desired percentile of total counts.
  26 static const uint32_t DefaultCutoffsData[] = {
  27     10000,  /*  1% */
  28     100000, /* 10% */
  29     200000, 300000, 400000, 500000, 600000, 700000, 800000,
  30     900000, 950000, 990000, 999000, 999900, 999990, 999999};
  31 const ArrayRef<uint32_t> ProfileSummaryBuilder::DefaultCutoffs =
  32     DefaultCutoffsData;
  33
  34 void InstrProfSummaryBuilder::addRecord(const InstrProfRecord &R) {
  35   // The first counter is not necessarily an entry count for IR
  36   // instrumentation profiles.
  37   // Eventually MaxFunctionCount will become obsolete and this can be
  38   // removed.
  39   addEntryCount(R.Counts[0]);
  40   for (size_t I = 1, E = R.Counts.size(); I < E; ++I)
  41     addInternalCount(R.Counts[I]);
  42 }
  43
  44 // To compute the detailed summary, we consider each line containing samples as
  45 // equivalent to a block with a count in the instrumented profile.
  46 void SampleProfileSummaryBuilder::addRecord(
  47     const sampleprof::FunctionSamples &FS, bool isCallsiteSample) {
  48   if (!isCallsiteSample) {
  49     NumFunctions++;
  50     if (FS.getHeadSamples() > MaxFunctionCount)
  51       MaxFunctionCount = FS.getHeadSamples();
  52   }
  53   for (const auto &I : FS.getBodySamples())
  54     addCount(I.second.getSamples());
  55   for (const auto &I : FS.getCallsiteSamples())
  56     for (const auto &CS : I.second)
  57       addRecord(CS.second, true);
  58 }
  59
  60 // The argument to this method is a vector of cutoff percentages and the return
  61 // value is a vector of (Cutoff, MinCount, NumCounts) triplets.
  62 void ProfileSummaryBuilder::computeDetailedSummary() {
  63   if (DetailedSummaryCutoffs.empty())
  64     return;
  65   llvm::sort(DetailedSummaryCutoffs);
  66   auto Iter = CountFrequencies.begin();
  67   const auto End = CountFrequencies.end();
  68
  69   uint32_t CountsSeen = 0;
  70   uint64_t CurrSum = 0, Count = 0;
  71
  72   for (const uint32_t Cutoff : DetailedSummaryCutoffs) {
  73     assert(Cutoff <= 999999);
  74     APInt Temp(128, TotalCount);
  75     APInt N(128, Cutoff);
  76     APInt D(128, ProfileSummary::Scale);
  77     Temp *= N;
  78     Temp = Temp.sdiv(D);
  79     uint64_t DesiredCount = Temp.getZExtValue();
  80     assert(DesiredCount <= TotalCount);
  81     while (CurrSum < DesiredCount && Iter != End) {
  82       Count = Iter->first;
  83       uint32_t Freq = Iter->second;
  84       CurrSum += (Count * Freq);
  85       CountsSeen += Freq;
  86       Iter++;
  87     }
  88     assert(CurrSum >= DesiredCount);
  89     ProfileSummaryEntry PSE = {Cutoff, Count, CountsSeen};
  90     DetailedSummary.push_back(PSE);
  91   }
  92 }
  93
  94 std::unique_ptr<ProfileSummary> SampleProfileSummaryBuilder::getSummary() {
  95   computeDetailedSummary();
  96   return std::make_unique<ProfileSummary>(
  97       ProfileSummary::PSK_Sample, DetailedSummary, TotalCount, MaxCount, 0,
  98       MaxFunctionCount, NumCounts, NumFunctions);
  99 }
 100
 101 std::unique_ptr<ProfileSummary> InstrProfSummaryBuilder::getSummary() {
 102   computeDetailedSummary();
 103   return std::make_unique<ProfileSummary>(
 104       ProfileSummary::PSK_Instr, DetailedSummary, TotalCount, MaxCount,
 105       MaxInternalBlockCount, MaxFunctionCount, NumCounts, NumFunctions);
 106 }
 107
 108 void InstrProfSummaryBuilder::addEntryCount(uint64_t Count) {
 109   addCount(Count);
 110   NumFunctions++;
 111   if (Count > MaxFunctionCount)
 112     MaxFunctionCount = Count;
 113 }
 114
 115 void InstrProfSummaryBuilder::addInternalCount(uint64_t Count) {
 116   addCount(Count);
 117   if (Count > MaxInternalBlockCount)
 118     MaxInternalBlockCount = Count;
 119 }