scoreboard.hh revision 7699 
1/*
2 * Copyright (c) 2005-2006 The Regents of The University of Michigan
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are
7 * met: redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer;
9 * redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution;
12 * neither the name of the copyright holders nor the names of its
13 * contributors may be used to endorse or promote products derived from
14 * this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
17 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
18 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
19 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
20 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 *
28 * Authors: Korey Sewell
29 *          Kevin Lim
30 */
31
32#ifndef __CPU_O3_SCOREBOARD_HH__
33#define __CPU_O3_SCOREBOARD_HH__
34
35#include <iostream>
36#include <utility>
37#include <vector>
38#include "base/trace.hh"
39#include "base/traceflags.hh"
40#include "cpu/o3/comm.hh"
41
42/**
43 * Implements a simple scoreboard to track which registers are ready.
44 * This class assumes that the fp registers start, index wise, right after
45 * the integer registers. The misc. registers start, index wise, right after
46 * the fp registers.
47 * @todo: Fix up handling of the zero register in case the decoder does not
48 * automatically make insts that write the zero register into nops.
49 */
50class Scoreboard
51{
52  public:
53    /** Constructs a scoreboard.
54     *  @param activeThreads The number of active threads.
55     *  @param _numLogicalIntRegs Number of logical integer registers.
56     *  @param _numPhysicalIntRegs Number of physical integer registers.
57     *  @param _numLogicalFloatRegs Number of logical fp registers.
58     *  @param _numPhysicalFloatRegs Number of physical fp registers.
59     *  @param _numMiscRegs Number of miscellaneous registers.
60     *  @param _zeroRegIdx Index of the zero register.
61     */
62    Scoreboard(unsigned activeThreads,
63               unsigned _numLogicalIntRegs,
64               unsigned _numPhysicalIntRegs,
65               unsigned _numLogicalFloatRegs,
66               unsigned _numPhysicalFloatRegs,
67               unsigned _numMiscRegs,
68               unsigned _zeroRegIdx);
69
70    /** Destructor. */
71    ~Scoreboard() {}
72
73    /** Returns the name of the scoreboard. */
74    std::string name() const;
75
76    /** Checks if the register is ready. */
77    bool getReg(PhysRegIndex ready_reg);
78
79    /** Sets the register as ready. */
80    void setReg(PhysRegIndex phys_reg);
81
82    /** Sets the register as not ready. */
83    void unsetReg(PhysRegIndex ready_reg);
84
85  private:
86    /** Scoreboard of physical integer registers, saying whether or not they
87     *  are ready.
88     */
89    std::vector<bool> regScoreBoard;
90
91    /** Number of logical integer registers. */
92    int numLogicalIntRegs;
93
94    /** Number of physical integer registers. */
95    int numPhysicalIntRegs;
96
97    /** Number of logical floating point registers. */
98    int numLogicalFloatRegs;
99
100    /** Number of physical floating point registers. */
101    int numPhysicalFloatRegs;
102
103    /** Number of miscellaneous registers. */
104    int numMiscRegs;
105
106    /** Number of logical integer + float registers. */
107    int numLogicalRegs;
108
109    /** Number of physical integer + float registers. */
110    int numPhysicalRegs;
111
112    /** The logical index of the zero register. */
113    int zeroRegIdx;
114
115    int currentSize;
116
117    void
118    resize(int newSize)
119    {
120        currentSize = newSize;
121        regScoreBoard.resize(newSize);
122    }
123
124    bool
125    indexInBounds(int idx)
126    {
127        return idx < currentSize;
128    }
129};
130
131#endif
132