1//===- IndirectCallPromotionAnalysis.h - Indirect call analysis -*- 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/// \file
9/// Interface to identify indirect call promotion candidates.
10///
11//===----------------------------------------------------------------------===//
12
13#ifndef LLVM_ANALYSIS_INDIRECTCALLPROMOTIONANALYSIS_H
14#define LLVM_ANALYSIS_INDIRECTCALLPROMOTIONANALYSIS_H
15
16#include "llvm/ProfileData/InstrProf.h"
17
18namespace llvm {
19
20class Instruction;
21
22// Class for identifying profitable indirect call promotion candidates when
23// the indirect-call value profile metadata is available.
24class ICallPromotionAnalysis {
25private:
26  // Allocate space to read the profile annotation.
27  std::unique_ptr<InstrProfValueData[]> ValueDataArray;
28
29  // Count is the call count for the direct-call target.
30  // TotalCount is the total call count for the indirect-call callsite.
31  // RemainingCount is the TotalCount minus promoted-direct-call count.
32  // Return true we should promote this indirect-call target.
33  bool isPromotionProfitable(uint64_t Count, uint64_t TotalCount,
34                             uint64_t RemainingCount);
35
36  // Returns the number of profitable candidates to promote for the
37  // current ValueDataArray and the given \p Inst.
38  uint32_t getProfitablePromotionCandidates(const Instruction *Inst,
39                                            uint32_t NumVals,
40                                            uint64_t TotalCount);
41
42  // Noncopyable
43  ICallPromotionAnalysis(const ICallPromotionAnalysis &other) = delete;
44  ICallPromotionAnalysis &
45  operator=(const ICallPromotionAnalysis &other) = delete;
46
47public:
48  ICallPromotionAnalysis();
49
50  /// Returns reference to array of InstrProfValueData for the given
51  /// instruction \p I.
52  ///
53  /// The \p NumVals, \p TotalCount and \p NumCandidates
54  /// are set to the number of values in the array, the total profile count
55  /// of the indirect call \p I, and the number of profitable candidates
56  /// in the given array (which is sorted in reverse order of profitability).
57  ///
58  /// The returned array space is owned by this class, and overwritten on
59  /// subsequent calls.
60  ArrayRef<InstrProfValueData>
61  getPromotionCandidatesForInstruction(const Instruction *I, uint32_t &NumVals,
62                                       uint64_t &TotalCount,
63                                       uint32_t &NumCandidates);
64};
65
66} // end namespace llvm
67
68#endif
69