1//===--------------------- SourceMgr.h --------------------------*- 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/// This file contains abstract class SourceMgr and the default implementation,
10/// CircularSourceMgr.
11///
12//===----------------------------------------------------------------------===//
13
14#ifndef LLVM_MCA_SOURCEMGR_H
15#define LLVM_MCA_SOURCEMGR_H
16
17#include "llvm/ADT/ArrayRef.h"
18#include "llvm/MCA/Instruction.h"
19
20namespace llvm {
21namespace mca {
22
23// MSVC >= 19.15, < 19.20 need to see the definition of class Instruction to
24// prevent compiler error C2139 about intrinsic type trait '__is_assignable'.
25typedef std::pair<unsigned, const Instruction &> SourceRef;
26
27/// Abstracting the input code sequence (a sequence of MCInst) and assigning
28/// unique identifiers to every instruction in the sequence.
29struct SourceMgr {
30 using UniqueInst = std::unique_ptr<Instruction>;
31
32 /// Provides a fixed range of \a UniqueInst to iterate.
33 virtual ArrayRef<UniqueInst> getInstructions() const = 0;
34
35 /// (Fixed) Number of \a UniqueInst. Returns the size of
36 /// \a getInstructions by default.
37 virtual size_t size() const { return getInstructions().size(); }
38
39 /// Whether there is any \a SourceRef to inspect / peek next.
40 /// Note that returning false from this doesn't mean the instruction
41 /// stream has ended.
42 virtual bool hasNext() const = 0;
43
44 /// Whether the instruction stream has eneded.
45 virtual bool isEnd() const = 0;
46
47 /// The next \a SourceRef.
48 virtual SourceRef peekNext() const = 0;
49
50 /// Advance to the next \a SourceRef.
51 virtual void updateNext() = 0;
52
53 virtual ~SourceMgr() {}
54};
55
56/// The default implementation of \a SourceMgr. It always takes a fixed number
57/// of instructions and provides an option to loop the given sequence for a
58/// certain iterations.
59class CircularSourceMgr : public SourceMgr {
60 ArrayRef<UniqueInst> Sequence;
61 unsigned Current;
62 const unsigned Iterations;
63 static const unsigned DefaultIterations = 100;
64
65public:
66 CircularSourceMgr(ArrayRef<UniqueInst> S, unsigned Iter)
67 : Sequence(S), Current(0U), Iterations(Iter ? Iter : DefaultIterations) {}
68
69 ArrayRef<UniqueInst> getInstructions() const override { return Sequence; }
70
71 unsigned getNumIterations() const { return Iterations; }
72 bool hasNext() const override {
73 return Current < (Iterations * Sequence.size());
74 }
75 bool isEnd() const override { return !hasNext(); }
76
77 SourceRef peekNext() const override {
78 assert(hasNext() && "Already at end of sequence!");
79 return SourceRef(Current, *Sequence[Current % Sequence.size()]);
80 }
81
82 void updateNext() override { ++Current; }
83};
84
85} // namespace mca
86} // namespace llvm
87
88#endif // LLVM_MCA_SOURCEMGR_H
89

source code of llvm/include/llvm/MCA/SourceMgr.h