llvm/lib/Transforms/Instrumentation/ValueProfileCollector.cpp

   1 //===- ValueProfileCollector.cpp - determine what to value profile --------===//
   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 // The implementation of the ValueProfileCollector via ValueProfileCollectorImpl
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "ValueProfileCollector.h"
  14 #include "ValueProfilePlugins.inc"
  15 #include "llvm/ProfileData/InstrProf.h"
  16
  17 using namespace llvm;
  18
  19 namespace {
  20
  21 /// A plugin-based class that takes an arbitrary number of Plugin types.
  22 /// Each plugin type must satisfy the following API:
  23 ///  1) the constructor must take a `Function &f`. Typically, the plugin would
  24 ///     scan the function looking for candidates.
  25 ///  2) contain a member function with the following signature and name:
  26 ///        void run(std::vector<CandidateInfo> &Candidates);
  27 ///    such that the plugin would append its result into the vector parameter.
  28 ///
  29 /// Plugins are defined in ValueProfilePlugins.inc
  30 template <class... Ts> class PluginChain;
  31
  32 /// The type PluginChainFinal is the final chain of plugins that will be used by
  33 /// ValueProfileCollectorImpl.
  34 using PluginChainFinal = PluginChain<VP_PLUGIN_LIST>;
  35
  36 template <> class PluginChain<> {
  37 public:
  38   PluginChain(Function &F, TargetLibraryInfo &TLI) {}
  39   void get(InstrProfValueKind K, std::vector<CandidateInfo> &Candidates) {}
  40 };
  41
  42 template <class PluginT, class... Ts>
  43 class PluginChain<PluginT, Ts...> : public PluginChain<Ts...> {
  44   PluginT Plugin;
  45   using Base = PluginChain<Ts...>;
  46
  47 public:
  48   PluginChain(Function &F, TargetLibraryInfo &TLI)
  49       : PluginChain<Ts...>(F, TLI), Plugin(F, TLI) {}
  50
  51   void get(InstrProfValueKind K, std::vector<CandidateInfo> &Candidates) {
  52     if (K == PluginT::Kind)
  53       Plugin.run(Candidates);
  54     Base::get(K, Candidates);
  55   }
  56 };
  57
  58 } // end anonymous namespace
  59
  60 /// ValueProfileCollectorImpl inherits the API of PluginChainFinal.
  61 class ValueProfileCollector::ValueProfileCollectorImpl : public PluginChainFinal {
  62 public:
  63   using PluginChainFinal::PluginChainFinal;
  64 };
  65
  66 ValueProfileCollector::ValueProfileCollector(Function &F,
  67                                              TargetLibraryInfo &TLI)
  68     : PImpl(new ValueProfileCollectorImpl(F, TLI)) {}
  69
  70 ValueProfileCollector::~ValueProfileCollector() = default;
  71
  72 std::vector<CandidateInfo>
  73 ValueProfileCollector::get(InstrProfValueKind Kind) const {
  74   std::vector<CandidateInfo> Result;
  75   PImpl->get(Kind, Result);
  76   return Result;
  77 }