klibc/jrand48.c

/*
 * jrand48.c
 */

#include <stdlib.h>
#include <stdint.h>

long jrand48(unsigned short xsubi[3])
{
  uint64_t x;

  /* The xsubi[] array is littleendian by spec */
  x = (uint64_t)(uint16_t)xsubi[0] +
    ((uint64_t)(uint16_t)xsubi[1] << 16) +
    ((uint64_t)(uint16_t)xsubi[2] << 32);

  x = (0x5deece66dULL * x) + 0xb;
  
  xsubi[0] = (unsigned short)(uint16_t)x;
  xsubi[1] = (unsigned short)(uint16_t)(x >> 16);
  xsubi[2] = (unsigned short)(uint16_t)(x >> 32);

  return (long)(int32_t)(x >> 16);
}