src/cpu/o3/rename_map.hh

   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
  44 class 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__