src/base/types.hh

   1 /*
   2  * Copyright (c) 2003-2005 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: Nathan Binkert
  29  */
  30
  31 /**
  32  * @file
  33  * Defines global host-dependent types:
  34  * Counter, Tick, and (indirectly) {int,uint}{8,16,32,64}_t.
  35  */
  36
  37 #ifndef __BASE_TYPES_HH__
  38 #define __BASE_TYPES_HH__
  39
  40 #include <inttypes.h>
  41
  42 #include <cassert>
  43 #include <memory>
  44 #include <ostream>
  45
  46 #include "base/refcnt.hh"
  47
  48 /** uint64_t constant */
  49 #define ULL(N)          ((uint64_t)N##ULL)
  50 /** int64_t constant */
  51 #define LL(N)           ((int64_t)N##LL)
  52
  53 /** Statistics counter type.  Not much excuse for not using a 64-bit
  54  * integer here, but if you're desperate and only run short
  55  * simulations you could make this 32 bits.
  56  */
  57 typedef int64_t Counter;
  58
  59 /**
  60  * Tick count type.
  61  */
  62 typedef uint64_t Tick;
  63
  64 const Tick MaxTick = ULL(0xffffffffffffffff);
  65
  66 /**
  67  * Cycles is a wrapper class for representing cycle counts, i.e. a
  68  * relative difference between two points in time, expressed in a
  69  * number of clock cycles.
  70  *
  71  * The Cycles wrapper class is a type-safe alternative to a
  72  * typedef, aiming to avoid unintentional mixing of cycles and ticks
  73  * in the code base.
  74  *
  75  * Operators are defined inside an ifndef block to avoid swig touching
  76  * them. Note that there is no overloading of the bool operator as the
  77  * compiler is allowed to turn booleans into integers and this causes
  78  * a whole range of issues in a handful locations. The solution to
  79  * this problem would be to use the safe bool idiom, but for now we
  80  * make do without the test and use the more elaborate comparison >
  81  * Cycles(0).
  82  */
  83 class Cycles
  84 {
  85
  86   private:
  87
  88     /** Member holding the actual value. */
  89     uint64_t c;
  90
  91   public:
  92
  93     /** Explicit constructor assigning a value. */
  94     explicit Cycles(uint64_t _c) : c(_c) { }
  95
  96     /** Default constructor for parameter classes. */
  97     Cycles() : c(0) { }
  98
  99 #ifndef SWIG // keep the operators away from SWIG
 100
 101     /** Converting back to the value type. */
 102     operator uint64_t() const { return c; }
 103
 104     /** Prefix increment operator. */
 105     Cycles& operator++()
 106     { ++c; return *this; }
 107
 108     /** Prefix decrement operator. Is only temporarily used in the O3 CPU. */
 109     Cycles& operator--()
 110     { assert(c != 0); --c; return *this; }
 111
 112     /** In-place addition of cycles. */
 113     const Cycles& operator+=(const Cycles& cc)
 114     { c += cc.c; return *this; }
 115
 116     /** Greater than comparison used for > Cycles(0). */
 117     bool operator>(const Cycles& cc) const
 118     { return c > cc.c; }
 119
 120     const Cycles operator +(const Cycles& b) const
 121     { return Cycles(c + b.c); }
 122
 123     const Cycles operator -(const Cycles& b) const
 124     { assert(c >= b.c); return Cycles(c - b.c); }
 125
 126     const Cycles operator <<(const int32_t shift)
 127     { return Cycles(c << shift); }
 128
 129     const Cycles operator >>(const int32_t shift)
 130     { return Cycles(c >> shift); }
 131
 132     friend std::ostream& operator<<(std::ostream &out, const Cycles & cycles);
 133
 134 #endif // SWIG not touching operators
 135
 136 };
 137
 138 /**
 139  * Address type
 140  * This will probably be moved somewhere else in the near future.
 141  * This should be at least as big as the biggest address width in use
 142  * in the system, which will probably be 64 bits.
 143  */
 144 typedef uint64_t Addr;
 145
 146 typedef uint16_t MicroPC;
 147
 148 static const MicroPC MicroPCRomBit = 1 << (sizeof(MicroPC) * 8 - 1);
 149
 150 static inline MicroPC
 151 romMicroPC(MicroPC upc)
 152 {
 153     return upc | MicroPCRomBit;
 154 }
 155
 156 static inline MicroPC
 157 normalMicroPC(MicroPC upc)
 158 {
 159     return upc & ~MicroPCRomBit;
 160 }
 161
 162 static inline bool
 163 isRomMicroPC(MicroPC upc)
 164 {
 165     return MicroPCRomBit & upc;
 166 }
 167
 168 const Addr MaxAddr = (Addr)-1;
 169
 170 /**
 171  * Thread index/ID type
 172  */
 173 typedef int16_t ThreadID;
 174 const ThreadID InvalidThreadID = (ThreadID)-1;
 175
 176 /**
 177  * Port index/ID type, and a symbolic name for an invalid port id.
 178  */
 179 typedef int16_t PortID;
 180 const PortID InvalidPortID = (PortID)-1;
 181
 182 class FaultBase;
 183 typedef std::shared_ptr<FaultBase> Fault;
 184
 185 #ifndef SWIG // Swig gets really confused by decltype
 186 // Rather than creating a shared_ptr instance and assigning it nullptr,
 187 // we just create an alias.
 188 constexpr decltype(nullptr) NoFault = nullptr;
 189 #endif
 190
 191 enum ByteOrder {
 192     BigEndianByteOrder,
 193     LittleEndianByteOrder
 194 };
 195
 196 #endif // __BASE_TYPES_HH__