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
23namespace llvm {
24namespace mca {
25
26class 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  Error getNextInstruction();
34
35  EntryStage(const EntryStage &Other) = delete;
36  EntryStage &operator=(const EntryStage &Other) = delete;
37
38public:
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 cycleResume() override;
46  Error cycleEnd() override;
47};
48
49} // namespace mca
50} // namespace llvm
51
52#endif // LLVM_MCA_STAGES_ENTRYSTAGE_H
53