| //===---------------------- EntryStage.cpp ----------------------*- C++ -*-===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| /// \file |
| /// |
| /// This file defines the Fetch stage of an instruction pipeline. Its sole |
| /// purpose in life is to produce instructions for the rest of the pipeline. |
| /// |
| //===----------------------------------------------------------------------===// |
| |
| #include "llvm/MCA/Stages/EntryStage.h" |
| #include "llvm/MCA/Instruction.h" |
| |
| namespace llvm { |
| namespace mca { |
| |
| bool EntryStage::hasWorkToComplete() const { |
| return static_cast<bool>(CurrentInstruction); |
| } |
| |
| bool EntryStage::isAvailable(const InstRef & /* unused */) const { |
| if (CurrentInstruction) |
| return checkNextStage(CurrentInstruction); |
| return false; |
| } |
| |
| void EntryStage::getNextInstruction() { |
| assert(!CurrentInstruction && "There is already an instruction to process!"); |
| if (!SM.hasNext()) |
| return; |
| SourceRef SR = SM.peekNext(); |
| std::unique_ptr<Instruction> Inst = std::make_unique<Instruction>(SR.second); |
| CurrentInstruction = InstRef(SR.first, Inst.get()); |
| Instructions.emplace_back(std::move(Inst)); |
| SM.updateNext(); |
| } |
| |
| llvm::Error EntryStage::execute(InstRef & /*unused */) { |
| assert(CurrentInstruction && "There is no instruction to process!"); |
| if (llvm::Error Val = moveToTheNextStage(CurrentInstruction)) |
| return Val; |
| |
| // Move the program counter. |
| CurrentInstruction.invalidate(); |
| getNextInstruction(); |
| return llvm::ErrorSuccess(); |
| } |
| |
| llvm::Error EntryStage::cycleStart() { |
| if (!CurrentInstruction) |
| getNextInstruction(); |
| return llvm::ErrorSuccess(); |
| } |
| |
| llvm::Error EntryStage::cycleEnd() { |
| // Find the first instruction which hasn't been retired. |
| auto Range = make_range(&Instructions[NumRetired], Instructions.end()); |
| auto It = find_if(Range, [](const std::unique_ptr<Instruction> &I) { |
| return !I->isRetired(); |
| }); |
| |
| NumRetired = std::distance(Instructions.begin(), It); |
| // Erase instructions up to the first that hasn't been retired. |
| if ((NumRetired * 2) >= Instructions.size()) { |
| Instructions.erase(Instructions.begin(), It); |
| NumRetired = 0; |
| } |
| |
| return llvm::ErrorSuccess(); |
| } |
| |
| } // namespace mca |
| } // namespace llvm |