src/base/random.cc

   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  *          Ali Saidi
  30  */
  31
  32 #ifdef __SUNPRO_CC
  33 #include <stdlib.h>
  34 #include <math.h>
  35 #endif
  36
  37 #include <cstdlib>
  38 #include <cmath>
  39
  40 #include "base/fenv.hh"
  41 #include "base/random.hh"
  42
  43 using namespace std;
  44
  45 uint32_t
  46 getInt32()
  47 {
  48     return mrand48() & 0xffffffff;
  49 }
  50
  51 double
  52 getDouble()
  53 {
  54     return drand48();
  55 }
  56
  57 double
  58 m5round(double r)
  59 {
  60 #if defined(__sun)
  61     double val;
  62     int oldrnd = m5_fegetround();
  63     m5_fesetround(M5_FE_TONEAREST);
  64     val = rint(r);
  65     m5_fesetround(oldrnd);
  66     return val;
  67 #else
  68     return round(r);
  69 #endif
  70 }
  71
  72 int64_t
  73 getUniform(int64_t min, int64_t max)
  74 {
  75     double r;
  76     r = drand48() * (max-min) + min;
  77
  78     return (int64_t)m5round(r);
  79 }
  80
  81 uint64_t
  82 getUniformPos(uint64_t min, uint64_t max)
  83 {
  84     double r;
  85     r = drand48() * (max-min) + min;
  86
  87     return (uint64_t)m5round(r);
  88 }