1 //===---------------------- EntryStage.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 the Entry stage of an instruction pipeline.  Its sole
11 /// purpose in life is to pick instructions in sequence and move them to the
12 /// next pipeline stage.
13 ///
14 //===----------------------------------------------------------------------===//
15 
16 #ifndef LLVM_MCA_STAGES_ENTRYSTAGE_H
17 #define LLVM_MCA_STAGES_ENTRYSTAGE_H
18 
19 #include "llvm/ADT/SmallVector.h"
20 #include "llvm/MCA/SourceMgr.h"
21 #include "llvm/MCA/Stages/Stage.h"
22 
23 namespace llvm {
24 namespace mca {
25 
26 class EntryStage final : public Stage {
27   InstRef CurrentInstruction;
28   SmallVector<std::unique_ptr<Instruction>, 16> Instructions;
29   SourceMgr &SM;
30   unsigned NumRetired;
31 
32   // Updates the program counter, and sets 'CurrentInstruction'.
33   void getNextInstruction();
34 
35   EntryStage(const EntryStage &Other) = delete;
36   EntryStage &operator=(const EntryStage &Other) = delete;
37 
38 public:
39   EntryStage(SourceMgr &SM) : SM(SM), NumRetired(0) {}
40 
41   bool isAvailable(const InstRef &IR) const override;
42   bool hasWorkToComplete() const override;
43   Error execute(InstRef &IR) override;
44   Error cycleStart() override;
45   Error cycleEnd() override;
46 };
47 
48 } // namespace mca
49 } // namespace llvm
50 
51 #endif // LLVM_MCA_STAGES_ENTRYSTAGE_H
52