rename_map.hh revision 1763 
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
42class SimpleRenameMap
43{
44  public:
45    /**
46     * Pair of a logical register and a physical register.  Tells the
47     * previous mapping of a logical register to a physical register.
48     * Used to roll back the rename map to a previous state.
49     */
50    typedef std::pair<RegIndex, PhysRegIndex> UnmapInfo;
51
52    /**
53     * Pair of a physical register and a physical register.  Used to
54     * return the physical register that a logical register has been
55     * renamed to, and the previous physical register that the same
56     * logical register was previously mapped to.
57     */
58    typedef std::pair<PhysRegIndex, PhysRegIndex> RenameInfo;
59
60  public:
61    //Constructor
62    SimpleRenameMap(unsigned _numLogicalIntRegs,
63                    unsigned _numPhysicalIntRegs,
64                    unsigned _numLogicalFloatRegs,
65                    unsigned _numPhysicalFloatRegs,
66                    unsigned _numMiscRegs,
67                    RegIndex _intZeroReg,
68                    RegIndex _floatZeroReg);
69
70    /** Destructor. */
71    ~SimpleRenameMap();
72
73    void setFreeList(SimpleFreeList *fl_ptr);
74
75    //Tell rename map to get a free physical register for a given
76    //architected register.  Not sure it should have a return value,
77    //but perhaps it should have some sort of fault in case there are
78    //no free registers.
79    RenameInfo rename(RegIndex arch_reg);
80
81    PhysRegIndex lookup(RegIndex phys_reg);
82
83    bool isReady(PhysRegIndex arch_reg);
84
85    /**
86     * Marks the given register as ready, meaning that its value has been
87     * calculated and written to the register file.
88     * @param ready_reg The index of the physical register that is now ready.
89     */
90    void markAsReady(PhysRegIndex ready_reg);
91
92    void setEntry(RegIndex arch_reg, PhysRegIndex renamed_reg);
93
94    void squash(std::vector<RegIndex> freed_regs,
95                std::vector<UnmapInfo> unmaps);
96
97    int numFreeEntries();
98
99  private:
100    /** Number of logical integer registers. */
101    int numLogicalIntRegs;
102
103    /** Number of physical integer registers. */
104    int numPhysicalIntRegs;
105
106    /** Number of logical floating point registers. */
107    int numLogicalFloatRegs;
108
109    /** Number of physical floating point registers. */
110    int numPhysicalFloatRegs;
111
112    /** Number of miscellaneous registers. */
113    int numMiscRegs;
114
115    /** Number of logical integer + float registers. */
116    int numLogicalRegs;
117
118    /** Number of physical integer + float registers. */
119    int numPhysicalRegs;
120
121    /** The integer zero register.  This implementation assumes it is always
122     *  zero and never can be anything else.
123     */
124    RegIndex intZeroReg;
125
126    /** The floating point zero register.  This implementation assumes it is
127     *  always zero and never can be anything else.
128     */
129    RegIndex floatZeroReg;
130
131    class RenameEntry
132    {
133      public:
134        PhysRegIndex physical_reg;
135        bool valid;
136
137        RenameEntry()
138            : physical_reg(0), valid(false)
139        { }
140    };
141
142    /** Integer rename map. */
143    RenameEntry *intRenameMap;
144
145    /** Floating point rename map. */
146    RenameEntry *floatRenameMap;
147
148    /** Free list interface. */
149    SimpleFreeList *freeList;
150
151    // Might want to make all these scoreboards into one large scoreboard.
152
153    /** Scoreboard of physical integer registers, saying whether or not they
154     *  are ready.
155     */
156    std::vector<bool> intScoreboard;
157
158    /** Scoreboard of physical floating registers, saying whether or not they
159     *  are ready.
160     */
161    std::vector<bool> floatScoreboard;
162
163    /** Scoreboard of miscellaneous registers, saying whether or not they
164     *  are ready.
165     */
166    std::vector<bool> miscScoreboard;
167};
168
169#endif //__CPU_O3_CPU_RENAME_MAP_HH__
170