1 ////===- SampleProfileLoadBaseUtil.h - Profile loader util func --*- 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 //
9 /// \file
10 /// This file provides the utility functions for the sampled PGO loader base
11 /// implementation.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #ifndef LLVM_TRANSFORMS_UTILS_SAMPLEPROFILELOADERBASEUTIL_H
16 #define LLVM_TRANSFORMS_UTILS_SAMPLEPROFILELOADERBASEUTIL_H
17 
18 #include "llvm/ADT/DenseMap.h"
19 #include "llvm/Analysis/ProfileSummaryInfo.h"
20 #include "llvm/IR/BasicBlock.h"
21 #include "llvm/IR/CFG.h"
22 #include "llvm/IR/Constants.h"
23 #include "llvm/IR/DebugLoc.h"
24 #include "llvm/IR/Function.h"
25 #include "llvm/ProfileData/SampleProf.h"
26 #include "llvm/Support/CommandLine.h"
27 #include "llvm/Transforms/Utils/ModuleUtils.h"
28 
29 namespace llvm {
30 using namespace sampleprof;
31 
32 class ProfileSummaryInfo;
33 
34 extern cl::opt<unsigned> SampleProfileMaxPropagateIterations;
35 extern cl::opt<unsigned> SampleProfileRecordCoverage;
36 extern cl::opt<unsigned> SampleProfileSampleCoverage;
37 extern cl::opt<bool> NoWarnSampleUnused;
38 
39 namespace sampleprofutil {
40 
41 class SampleCoverageTracker {
42 public:
43   bool markSamplesUsed(const FunctionSamples *FS, uint32_t LineOffset,
44                        uint32_t Discriminator, uint64_t Samples);
45   unsigned computeCoverage(unsigned Used, unsigned Total) const;
46   unsigned countUsedRecords(const FunctionSamples *FS,
47                             ProfileSummaryInfo *PSI) const;
48   unsigned countBodyRecords(const FunctionSamples *FS,
49                             ProfileSummaryInfo *PSI) const;
getTotalUsedSamples()50   uint64_t getTotalUsedSamples() const { return TotalUsedSamples; }
51   uint64_t countBodySamples(const FunctionSamples *FS,
52                             ProfileSummaryInfo *PSI) const;
53 
clear()54   void clear() {
55     SampleCoverage.clear();
56     TotalUsedSamples = 0;
57   }
setProfAccForSymsInList(bool V)58   void setProfAccForSymsInList(bool V) { ProfAccForSymsInList = V; }
59 
60 private:
61   using BodySampleCoverageMap = std::map<LineLocation, unsigned>;
62   using FunctionSamplesCoverageMap =
63       DenseMap<const FunctionSamples *, BodySampleCoverageMap>;
64 
65   /// Coverage map for sampling records.
66   ///
67   /// This map keeps a record of sampling records that have been matched to
68   /// an IR instruction. This is used to detect some form of staleness in
69   /// profiles (see flag -sample-profile-check-coverage).
70   ///
71   /// Each entry in the map corresponds to a FunctionSamples instance.  This is
72   /// another map that counts how many times the sample record at the
73   /// given location has been used.
74   FunctionSamplesCoverageMap SampleCoverage;
75 
76   /// Number of samples used from the profile.
77   ///
78   /// When a sampling record is used for the first time, the samples from
79   /// that record are added to this accumulator.  Coverage is later computed
80   /// based on the total number of samples available in this function and
81   /// its callsites.
82   ///
83   /// Note that this accumulator tracks samples used from a single function
84   /// and all the inlined callsites. Strictly, we should have a map of counters
85   /// keyed by FunctionSamples pointers, but these stats are cleared after
86   /// every function, so we just need to keep a single counter.
87   uint64_t TotalUsedSamples = 0;
88 
89   // For symbol in profile symbol list, whether to regard their profiles
90   // to be accurate. This is passed from the SampleLoader instance.
91   bool ProfAccForSymsInList = false;
92 };
93 
94 /// Return true if the given callsite is hot wrt to hot cutoff threshold.
95 bool callsiteIsHot(const FunctionSamples *CallsiteFS, ProfileSummaryInfo *PSI,
96                    bool ProfAccForSymsInList);
97 
98 /// Create a global variable to flag FSDiscriminators are used.
99 void createFSDiscriminatorVariable(Module *M);
100 
101 } // end of namespace sampleprofutil
102 } // end of namespace llvm
103 
104 #endif // LLVM_TRANSFORMS_UTILS_SAMPLEPROFILELOADERBASEUTIL_H
105