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 | |
20 | namespace llvm { |
21 | namespace 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'. |
25 | typedef 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. |
29 | struct 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. |
59 | class CircularSourceMgr : public SourceMgr { |
60 | ArrayRef<UniqueInst> Sequence; |
61 | unsigned Current; |
62 | const unsigned Iterations; |
63 | static const unsigned DefaultIterations = 100; |
64 | |
65 | public: |
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 | |