gen/FreeBSD/rand48.h.patch

   1 --- rand48.h.orig       2003-05-20 15:21:02.000000000 -0700
   2 +++ rand48.h    2005-11-03 14:06:17.000000000 -0800
   3 @@ -19,8 +19,6 @@
   4  #include <math.h>
   5  #include <stdlib.h>
   6
   7 -void           _dorand48(unsigned short[3]);
   8 -
   9  #define        RAND48_SEED_0   (0x330e)
  10  #define        RAND48_SEED_1   (0xabcd)
  11  #define        RAND48_SEED_2   (0x1234)
  12 @@ -29,4 +27,55 @@
  13  #define        RAND48_MULT_2   (0x0005)
  14  #define        RAND48_ADD      (0x000b)
  15
  16 +typedef unsigned long long uint48;
  17 +
  18 +extern uint48 _rand48_seed;
  19 +extern uint48 _rand48_mult;
  20 +extern uint48 _rand48_add;
  21 +
  22 +#define TOUINT48(x,y,z) \
  23 +       ((uint48)(x) + (((uint48)(y)) << 16) + (((uint48)(z)) << 32))
  24 +
  25 +#define RAND48_SEED    TOUINT48(RAND48_SEED_0, RAND48_SEED_1, RAND48_SEED_2)
  26 +#define RAND48_MULT    TOUINT48(RAND48_MULT_0, RAND48_MULT_1, RAND48_MULT_2)
  27 +
  28 +#define LOADRAND48(l,x) \
  29 +       (l) = TOUINT48((x)[0], (x)[1], (x)[2])
  30 +
  31 +#define STORERAND48(l,x) \
  32 +       (x)[0] = (unsigned short)(l); \
  33 +       (x)[1] = (unsigned short)((l) >> 16); \
  34 +       (x)[2] = (unsigned short)((l) >> 32)
  35 +
  36 +#define _DORAND48(l) \
  37 +       (l) = (l) * _rand48_mult + _rand48_add
  38 +
  39 +#define DORAND48(l,x) \
  40 +       LOADRAND48(l, x); \
  41 +       _DORAND48(l); \
  42 +       STORERAND48(l, x)
  43 +
  44 +#include "fpmath.h"
  45 +
  46 +/*
  47 + * Optimization for speed: avoid int-to-double conversion.  Assume doubles
  48 + * are IEEE-754 and insert the bits directly.  To normalize, the (1 << 52)
  49 + * is the hidden bit, which the first set bit is shifted to.
  50 + */
  51 +#define ERAND48_BEGIN \
  52 +       union { \
  53 +               union IEEEd2bits ieee; \
  54 +               unsigned long long l; \
  55 +       } u; \
  56 +       int s
  57 +
  58 +#define ERAND48_END(x) \
  59 +       u.l = ((x) & 0xffffffffffffULL); \
  60 +       if (u.l == 0) \
  61 +               return 0.0; \
  62 +       u.l <<= 5; \
  63 +       for(s = 0; !(u.l & (1LL << 52)); s++, u.l <<= 1) {} \
  64 +       u.ieee.bits.exp = 1022 - s; \
  65 +       return u.ieee.d
  66 +
  67  #endif /* _RAND48_H_ */