scoreboard.hh

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/*
 * Copyright (c) 2005-2006 The Regents of The University of Michigan
 * Copyright (c) 2013 Advanced Micro Devices, Inc.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met: redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer;
 * redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution;
 * neither the name of the copyright holders nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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 */
 
#ifndef __CPU_O3_SCOREBOARD_HH__
#define __CPU_O3_SCOREBOARD_HH__
 
#include <cassert>
#include <vector>
 
#include "base/compiler.hh"
#include "base/trace.hh"
#include "cpu/reg_class.hh"
#include "debug/Scoreboard.hh"
 
namespace gem5
{
 
namespace o3
{
 
class Scoreboard
{
  private:
    const std::string _name;
 
    const RegIndex zeroReg;
 
    std::vector<bool> regScoreBoard;
 
    GEM5_CLASS_VAR_USED unsigned numPhysRegs;
 
  public:
    Scoreboard(const std::string &_my_name, unsigned _numPhysicalRegs,
               RegIndex _zero_reg);
 
    ~Scoreboard() {}
 
    std::string name() const { return _name; };
 
    bool
    getReg(PhysRegIdPtr phys_reg) const
    {
        assert(phys_reg->flatIndex() < numPhysRegs);
 
        if (phys_reg->isFixedMapping()) {
            // Fixed mapping regs are always ready
            return true;
        }
 
        bool ready = regScoreBoard[phys_reg->flatIndex()];
 
        if (phys_reg->is(IntRegClass) && phys_reg->index() == zeroReg)
            assert(ready);
 
        return ready;
    }
 
    void
    setReg(PhysRegIdPtr phys_reg)
    {
        assert(phys_reg->flatIndex() < numPhysRegs);
 
        if (phys_reg->isFixedMapping()) {
            // Fixed mapping regs are always ready, ignore attempts to change
            // that
            return;
        }
 
        DPRINTF(Scoreboard, "Setting reg %i (%s) as ready\n",
                phys_reg->index(), phys_reg->className());
 
        regScoreBoard[phys_reg->flatIndex()] = true;
    }
 
    void
    unsetReg(PhysRegIdPtr phys_reg)
    {
        assert(phys_reg->flatIndex() < numPhysRegs);
 
        if (phys_reg->isFixedMapping()) {
            // Fixed mapping regs are always ready, ignore attempts to
            // change that
            return;
        }
 
        // zero reg should never be marked unready
        if (phys_reg->is(IntRegClass) && phys_reg->index() == zeroReg)
            return;
 
        regScoreBoard[phys_reg->flatIndex()] = false;
    }
 
};
 
} // namespace o3
} // namespace gem5
 
#endif