LLVM  11.0.0git
ValueProfileCollector.cpp
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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, TargetLibraryInfo &TLI) {}
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, TargetLibraryInfo &TLI)
52  : PluginChain<Ts...>(F, TLI), Plugin(F, TLI) {}
53 
54  void get(InstrProfValueKind K, std::vector<CandidateInfo> &Candidates) {
55  if (K == PluginT::Kind)
56  Plugin.run(Candidates);
57  Base::get(K, Candidates);
58  }
59 };
60 
61 } // end anonymous namespace
62 
63 /// ValueProfileCollectorImpl inherits the API of PluginChainFinal.
64 class ValueProfileCollector::ValueProfileCollectorImpl : public PluginChainFinal {
65 public:
66  using PluginChainFinal::PluginChainFinal;
67 };
68 
70  TargetLibraryInfo &TLI)
71  : PImpl(new ValueProfileCollectorImpl(F, TLI)) {}
72 
74 
75 std::vector<CandidateInfo>
77  std::vector<CandidateInfo> Result;
78  PImpl->get(Kind, Result);
79  return Result;
80 }
This class represents lattice values for constants.
Definition: AllocatorList.h:23
F(f)
ValueProfileCollector(Function &Fn, TargetLibraryInfo &TLI)
InstrProfValueKind
Definition: InstrProf.h:237
ValueProfileCollectorImpl inherits the API of PluginChainFinal.
Provides information about what library functions are available for the current target.
std::vector< CandidateInfo > get(InstrProfValueKind Kind) const
returns a list of value profiling candidates of the given kind