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 "ValueProfilePlugins.inc"
  14 #include "llvm/IR/InstIterator.h"
  15 #include "llvm/IR/IntrinsicInst.h"
  16 #include "llvm/InitializePasses.h"
  17
  18 #include <cassert>
  19
  20 using namespace llvm;
  21
  22 namespace {
  23
  24 /// A plugin-based class that takes an arbitrary number of Plugin types.
  25 /// Each plugin type must satisfy the following API:
  26 ///  1) the constructor must take a `Function &f`. Typically, the plugin would
  27 ///     scan the function looking for candidates.
  28 ///  2) contain a member function with the following signature and name:
  29 ///        void run(std::vector<CandidateInfo> &Candidates);
  30 ///    such that the plugin would append its result into the vector parameter.
  31 ///
  32 /// Plugins are defined in ValueProfilePlugins.inc
  33 template <class... Ts> class PluginChain;
  34
  35 /// The type PluginChainFinal is the final chain of plugins that will be used by
  36 /// ValueProfileCollectorImpl.
  37 using PluginChainFinal = PluginChain<VP_PLUGIN_LIST>;
  38
  39 template <> class PluginChain<> {
  40 public:
  41   PluginChain(Function &F) {}
  42   void get(InstrProfValueKind K, std::vector<CandidateInfo> &Candidates) {}
  43 };
  44
  45 template <class PluginT, class... Ts>
  46 class PluginChain<PluginT, Ts...> : public PluginChain<Ts...> {
  47   PluginT Plugin;
  48   using Base = PluginChain<Ts...>;
  49
  50 public:
  51   PluginChain(Function &F) : PluginChain<Ts...>(F), Plugin(F) {}
  52
  53   void get(InstrProfValueKind K, std::vector<CandidateInfo> &Candidates) {
  54     if (K == PluginT::Kind)
  55       Plugin.run(Candidates);
  56     Base::get(K, Candidates);
  57   }
  58 };
  59
  60 } // end anonymous namespace
  61
  62 /// ValueProfileCollectorImpl inherits the API of PluginChainFinal.
  63 class ValueProfileCollector::ValueProfileCollectorImpl : public PluginChainFinal {
  64 public:
  65   using PluginChainFinal::PluginChainFinal;
  66 };
  67
  68 ValueProfileCollector::ValueProfileCollector(Function &F)
  69     : PImpl(new ValueProfileCollectorImpl(F)) {}
  70
  71 ValueProfileCollector::~ValueProfileCollector() = default;
  72
  73 std::vector<CandidateInfo>
  74 ValueProfileCollector::get(InstrProfValueKind Kind) const {
  75   std::vector<CandidateInfo> Result;
  76   PImpl->get(Kind, Result);
  77   return Result;
  78 }