rename_map.hh revision 2348 
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_RENAME_MAP_HH__
34#define __CPU_O3_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    /** Default constructor.  init() must be called prior to use. */
66    SimpleRenameMap() {};
67
68    /** Destructor. */
69    ~SimpleRenameMap();
70
71    /** Initializes rename map with given parameters. */
72    void init(unsigned _numLogicalIntRegs,
73              unsigned _numPhysicalIntRegs,
74              PhysRegIndex &_int_reg_start,
75
76              unsigned _numLogicalFloatRegs,
77              unsigned _numPhysicalFloatRegs,
78              PhysRegIndex &_float_reg_start,
79
80              unsigned _numMiscRegs,
81
82              RegIndex _intZeroReg,
83              RegIndex _floatZeroReg,
84
85              int id,
86              bool bindRegs);
87
88    /** Sets the free list used with this rename map. */
89    void setFreeList(SimpleFreeList *fl_ptr);
90
91    //Tell rename map to get a free physical register for a given
92    //architected register.  Not sure it should have a return value,
93    //but perhaps it should have some sort of fault in case there are
94    //no free registers.
95    RenameInfo rename(RegIndex arch_reg);
96
97    PhysRegIndex lookup(RegIndex phys_reg);
98
99    /**
100     * Marks the given register as ready, meaning that its value has been
101     * calculated and written to the register file.
102     * @param ready_reg The index of the physical register that is now ready.
103     */
104    void setEntry(RegIndex arch_reg, PhysRegIndex renamed_reg);
105
106    int numFreeEntries();
107
108  private:
109    /** Rename Map ID  */
110    int id;
111
112    /** Number of logical integer registers. */
113    int numLogicalIntRegs;
114
115    /** Number of physical integer registers. */
116    int numPhysicalIntRegs;
117
118    /** Number of logical floating point registers. */
119    int numLogicalFloatRegs;
120
121    /** Number of physical floating point registers. */
122    int numPhysicalFloatRegs;
123
124    /** Number of miscellaneous registers. */
125    int numMiscRegs;
126
127    /** Number of logical integer + float registers. */
128    int numLogicalRegs;
129
130    /** Number of physical integer + float registers. */
131    int numPhysicalRegs;
132
133    /** The integer zero register.  This implementation assumes it is always
134     *  zero and never can be anything else.
135     */
136    RegIndex intZeroReg;
137
138    /** The floating point zero register.  This implementation assumes it is
139     *  always zero and never can be anything else.
140     */
141    RegIndex floatZeroReg;
142
143    class RenameEntry
144    {
145      public:
146        PhysRegIndex physical_reg;
147        bool valid;
148
149        RenameEntry()
150            : physical_reg(0), valid(false)
151        { }
152    };
153
154  private:
155    /** Integer rename map. */
156    std::vector<RenameEntry> intRenameMap;
157
158    /** Floating point rename map. */
159    std::vector<RenameEntry> floatRenameMap;
160
161  private:
162    /** Free list interface. */
163    SimpleFreeList *freeList;
164};
165
166#endif //__CPU_O3_RENAME_MAP_HH__
167