rename_map.hh revision 2665:a124942bacb8 
1/*
2 * Copyright (c) 2004-2005 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: Kevin Lim
29 */
30
31// Todo:  Create destructor.
32// Have it so that there's a more meaningful name given to the variable
33// that marks the beginning of the FP registers.
34
35#ifndef __CPU_O3_CPU_RENAME_MAP_HH__
36#define __CPU_O3_CPU_RENAME_MAP_HH__
37
38#include <iostream>
39#include <utility>
40#include <vector>
41
42#include "cpu/o3/free_list.hh"
43//For RegIndex
44#include "arch/isa_traits.hh"
45
46class SimpleRenameMap
47{
48  protected:
49    typedef TheISA::RegIndex RegIndex;
50  public:
51    /**
52     * Pair of a logical register and a physical register.  Tells the
53     * previous mapping of a logical register to a physical register.
54     * Used to roll back the rename map to a previous state.
55     */
56    typedef std::pair<RegIndex, PhysRegIndex> UnmapInfo;
57
58    /**
59     * Pair of a physical register and a physical register.  Used to
60     * return the physical register that a logical register has been
61     * renamed to, and the previous physical register that the same
62     * logical register was previously mapped to.
63     */
64    typedef std::pair<PhysRegIndex, PhysRegIndex> RenameInfo;
65
66  public:
67    //Constructor
68    SimpleRenameMap(unsigned _numLogicalIntRegs,
69                    unsigned _numPhysicalIntRegs,
70                    unsigned _numLogicalFloatRegs,
71                    unsigned _numPhysicalFloatRegs,
72                    unsigned _numMiscRegs,
73                    RegIndex _intZeroReg,
74                    RegIndex _floatZeroReg);
75
76    /** Destructor. */
77    ~SimpleRenameMap();
78
79    void setFreeList(SimpleFreeList *fl_ptr);
80
81    //Tell rename map to get a free physical register for a given
82    //architected register.  Not sure it should have a return value,
83    //but perhaps it should have some sort of fault in case there are
84    //no free registers.
85    RenameInfo rename(RegIndex arch_reg);
86
87    PhysRegIndex lookup(RegIndex phys_reg);
88
89    bool isReady(PhysRegIndex arch_reg);
90
91    /**
92     * Marks the given register as ready, meaning that its value has been
93     * calculated and written to the register file.
94     * @param ready_reg The index of the physical register that is now ready.
95     */
96    void markAsReady(PhysRegIndex ready_reg);
97
98    void setEntry(RegIndex arch_reg, PhysRegIndex renamed_reg);
99
100    void squash(std::vector<RegIndex> freed_regs,
101                std::vector<UnmapInfo> unmaps);
102
103    int numFreeEntries();
104
105  private:
106    /** Number of logical integer registers. */
107    int numLogicalIntRegs;
108
109    /** Number of physical integer registers. */
110    int numPhysicalIntRegs;
111
112    /** Number of logical floating point registers. */
113    int numLogicalFloatRegs;
114
115    /** Number of physical floating point registers. */
116    int numPhysicalFloatRegs;
117
118    /** Number of miscellaneous registers. */
119    int numMiscRegs;
120
121    /** Number of logical integer + float registers. */
122    int numLogicalRegs;
123
124    /** Number of physical integer + float registers. */
125    int numPhysicalRegs;
126
127    /** The integer zero register.  This implementation assumes it is always
128     *  zero and never can be anything else.
129     */
130    RegIndex intZeroReg;
131
132    /** The floating point zero register.  This implementation assumes it is
133     *  always zero and never can be anything else.
134     */
135    RegIndex floatZeroReg;
136
137    class RenameEntry
138    {
139      public:
140        PhysRegIndex physical_reg;
141        bool valid;
142
143        RenameEntry()
144            : physical_reg(0), valid(false)
145        { }
146    };
147
148    /** Integer rename map. */
149    RenameEntry *intRenameMap;
150
151    /** Floating point rename map. */
152    RenameEntry *floatRenameMap;
153
154    /** Free list interface. */
155    SimpleFreeList *freeList;
156
157    // Might want to make all these scoreboards into one large scoreboard.
158
159    /** Scoreboard of physical integer registers, saying whether or not they
160     *  are ready.
161     */
162    std::vector<bool> intScoreboard;
163
164    /** Scoreboard of physical floating registers, saying whether or not they
165     *  are ready.
166     */
167    std::vector<bool> floatScoreboard;
168
169    /** Scoreboard of miscellaneous registers, saying whether or not they
170     *  are ready.
171     */
172    std::vector<bool> miscScoreboard;
173};
174
175#endif //__CPU_O3_CPU_RENAME_MAP_HH__
176