LLVM  10.0.0svn
Stage.h
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1 //===---------------------- Stage.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 ///
10 /// This file defines a stage.
11 /// A chain of stages compose an instruction pipeline.
12 ///
13 //===----------------------------------------------------------------------===//
14 
15 #ifndef LLVM_MCA_STAGE_H
16 #define LLVM_MCA_STAGE_H
17 
19 #include "llvm/Support/Error.h"
20 #include <set>
21 
22 namespace llvm {
23 namespace mca {
24 
25 class InstRef;
26 
27 class Stage {
28  Stage *NextInSequence;
29  std::set<HWEventListener *> Listeners;
30 
31  Stage(const Stage &Other) = delete;
32  Stage &operator=(const Stage &Other) = delete;
33 
34 protected:
35  const std::set<HWEventListener *> &getListeners() const { return Listeners; }
36 
37 public:
38  Stage() : NextInSequence(nullptr) {}
39  virtual ~Stage();
40 
41  /// Returns true if it can execute IR during this cycle.
42  virtual bool isAvailable(const InstRef &IR) const { return true; }
43 
44  /// Returns true if some instructions are still executing this stage.
45  virtual bool hasWorkToComplete() const = 0;
46 
47  /// Called once at the start of each cycle. This can be used as a setup
48  /// phase to prepare for the executions during the cycle.
49  virtual Error cycleStart() { return ErrorSuccess(); }
50 
51  /// Called once at the end of each cycle.
52  virtual Error cycleEnd() { return ErrorSuccess(); }
53 
54  /// The primary action that this stage performs on instruction IR.
55  virtual Error execute(InstRef &IR) = 0;
56 
57  void setNextInSequence(Stage *NextStage) {
58  assert(!NextInSequence && "This stage already has a NextInSequence!");
59  NextInSequence = NextStage;
60  }
61 
62  bool checkNextStage(const InstRef &IR) const {
63  return NextInSequence && NextInSequence->isAvailable(IR);
64  }
65 
66  /// Called when an instruction is ready to move the next pipeline stage.
67  ///
68  /// Stages are responsible for moving instructions to their immediate
69  /// successor stages.
71  assert(checkNextStage(IR) && "Next stage is not ready!");
72  return NextInSequence->execute(IR);
73  }
74 
75  /// Add a listener to receive callbacks during the execution of this stage.
76  void addListener(HWEventListener *Listener);
77 
78  /// Notify listeners of a particular hardware event.
79  template <typename EventT> void notifyEvent(const EventT &Event) const {
80  for (HWEventListener *Listener : Listeners)
81  Listener->onEvent(Event);
82  }
83 };
84 
85 } // namespace mca
86 } // namespace llvm
87 #endif // LLVM_MCA_STAGE_H
void notifyEvent(const EventT &Event) const
Notify listeners of a particular hardware event.
Definition: Stage.h:79
This class represents lattice values for constants.
Definition: AllocatorList.h:23
virtual Error execute(InstRef &IR)=0
The primary action that this stage performs on instruction IR.
const std::set< HWEventListener * > & getListeners() const
Definition: Stage.h:35
Subclass of Error for the sole purpose of identifying the success path in the type system...
Definition: Error.h:324
Optional< std::vector< StOtherPiece > > Other
Definition: ELFYAML.cpp:952
bool checkNextStage(const InstRef &IR) const
Definition: Stage.h:62
An InstRef contains both a SourceMgr index and Instruction pair.
Definition: Instruction.h:562
virtual Error cycleStart()
Called once at the start of each cycle.
Definition: Stage.h:49
virtual ~Stage()
void addListener(HWEventListener *Listener)
Add a listener to receive callbacks during the execution of this stage.
Definition: Stage.cpp:23
virtual bool isAvailable(const InstRef &IR) const
Returns true if it can execute IR during this cycle.
Definition: Stage.h:42
virtual Error cycleEnd()
Called once at the end of each cycle.
Definition: Stage.h:52
This file defines the main interface for hardware event listeners.
virtual void onEvent(const HWInstructionEvent &Event)
Error moveToTheNextStage(InstRef &IR)
Called when an instruction is ready to move the next pipeline stage.
Definition: Stage.h:70
virtual bool hasWorkToComplete() const =0
Returns true if some instructions are still executing this stage.
void setNextInSequence(Stage *NextStage)
Definition: Stage.h:57
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
Lightweight error class with error context and mandatory checking.
Definition: Error.h:157
Statically lint checks LLVM IR
Definition: Lint.cpp:192