source: azure_iot_hub/trunk/musl-1.1.18/src/prng/drand48.c@ 388

#include <stdlib.h>
#include <inttypes.h>

uint64_t __rand48_step(unsigned short *xi, unsigned short *lc);
extern unsigned short __seed48[7];

double erand48(unsigned short s[3])
{
        union {
                uint64_t u;
                double f;
        } x = { 0x3ff0000000000000ULL | __rand48_step(s, __seed48+3)<<4 };
        return x.f - 1.0;
}

double drand48(void)
{
        return erand48(__seed48);
}