rename_map.hh revision 2107 
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
29// Todo:  Create destructor.
30// Have it so that there's a more meaningful name given to the variable
31// that marks the beginning of the FP registers.
32
33#ifndef __CPU_O3_CPU_RENAME_MAP_HH__
34#define __CPU_O3_CPU_RENAME_MAP_HH__
35
36#include <iostream>
37#include <utility>
38#include <vector>
39
40#include "cpu/o3/free_list.hh"
41//For RegIndex
42#include "arch/isa_traits.hh"
43
44class SimpleRenameMap
45{
46  protected:
47    typedef TheISA::RegIndex RegIndex;
48  public:
49    /**
50     * Pair of a logical register and a physical register.  Tells the
51     * previous mapping of a logical register to a physical register.
52     * Used to roll back the rename map to a previous state.
53     */
54    typedef std::pair<RegIndex, PhysRegIndex> UnmapInfo;
55
56    /**
57     * Pair of a physical register and a physical register.  Used to
58     * return the physical register that a logical register has been
59     * renamed to, and the previous physical register that the same
60     * logical register was previously mapped to.
61     */
62    typedef std::pair<PhysRegIndex, PhysRegIndex> RenameInfo;
63
64  public:
65    //Constructor
66    SimpleRenameMap(unsigned _numLogicalIntRegs,
67                    unsigned _numPhysicalIntRegs,
68                    unsigned _numLogicalFloatRegs,
69                    unsigned _numPhysicalFloatRegs,
70                    unsigned _numMiscRegs,
71                    RegIndex _intZeroReg,
72                    RegIndex _floatZeroReg);
73
74    /** Destructor. */
75    ~SimpleRenameMap();
76
77    void setFreeList(SimpleFreeList *fl_ptr);
78
79    //Tell rename map to get a free physical register for a given
80    //architected register.  Not sure it should have a return value,
81    //but perhaps it should have some sort of fault in case there are
82    //no free registers.
83    RenameInfo rename(RegIndex arch_reg);
84
85    PhysRegIndex lookup(RegIndex phys_reg);
86
87    bool isReady(PhysRegIndex arch_reg);
88
89    /**
90     * Marks the given register as ready, meaning that its value has been
91     * calculated and written to the register file.
92     * @param ready_reg The index of the physical register that is now ready.
93     */
94    void markAsReady(PhysRegIndex ready_reg);
95
96    void setEntry(RegIndex arch_reg, PhysRegIndex renamed_reg);
97
98    void squash(std::vector<RegIndex> freed_regs,
99                std::vector<UnmapInfo> unmaps);
100
101    int numFreeEntries();
102
103  private:
104    /** Number of logical integer registers. */
105    int numLogicalIntRegs;
106
107    /** Number of physical integer registers. */
108    int numPhysicalIntRegs;
109
110    /** Number of logical floating point registers. */
111    int numLogicalFloatRegs;
112
113    /** Number of physical floating point registers. */
114    int numPhysicalFloatRegs;
115
116    /** Number of miscellaneous registers. */
117    int numMiscRegs;
118
119    /** Number of logical integer + float registers. */
120    int numLogicalRegs;
121
122    /** Number of physical integer + float registers. */
123    int numPhysicalRegs;
124
125    /** The integer zero register.  This implementation assumes it is always
126     *  zero and never can be anything else.
127     */
128    RegIndex intZeroReg;
129
130    /** The floating point zero register.  This implementation assumes it is
131     *  always zero and never can be anything else.
132     */
133    RegIndex floatZeroReg;
134
135    class RenameEntry
136    {
137      public:
138        PhysRegIndex physical_reg;
139        bool valid;
140
141        RenameEntry()
142            : physical_reg(0), valid(false)
143        { }
144    };
145
146    /** Integer rename map. */
147    RenameEntry *intRenameMap;
148
149    /** Floating point rename map. */
150    RenameEntry *floatRenameMap;
151
152    /** Free list interface. */
153    SimpleFreeList *freeList;
154
155    // Might want to make all these scoreboards into one large scoreboard.
156
157    /** Scoreboard of physical integer registers, saying whether or not they
158     *  are ready.
159     */
160    std::vector<bool> intScoreboard;
161
162    /** Scoreboard of physical floating registers, saying whether or not they
163     *  are ready.
164     */
165    std::vector<bool> floatScoreboard;
166
167    /** Scoreboard of miscellaneous registers, saying whether or not they
168     *  are ready.
169     */
170    std::vector<bool> miscScoreboard;
171};
172
173#endif //__CPU_O3_CPU_RENAME_MAP_HH__
174