com32/lib/lrand48.c

   1 /*
   2  * lrand48.c
   3  */
   4
   5 #include <stdlib.h>
   6 #include <stdint.h>
   7
   8 unsigned short __rand48_seed[3];
   9
  10 long jrand48(unsigned short xsubi[3])
  11 {
  12   uint64_t x;
  13
  14   /* The xsubi[] array is littleendian by spec */
  15   x = (uint64_t)xsubi[0] +
  16     ((uint64_t)xsubi[1] << 16) +
  17     ((uint64_t)xsubi[2] << 32);
  18
  19   x = (0x5deece66dULL * x) + 0xb;
  20
  21   xsubi[0] = (unsigned short)x;
  22   xsubi[1] = (unsigned short)(x >> 16);
  23   xsubi[2] = (unsigned short)(x >> 32);
  24
  25   return (long)(int32_t)(x >> 16);
  26 }
  27
  28 long mrand48(void)
  29 {
  30   return jrand48(__rand48_seed);
  31 }
  32
  33 long nrand48(unsigned short xsubi[3])
  34 {
  35   return (long)((uint32_t)jrand48(xsubi) >> 1);
  36 }
  37
  38 long lrand48(void)
  39 {
  40   return (long)((uint32_t)(mrand48() >> 1));
  41 }