musl/src/prng/__rand48_step.c

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

uint64_t __rand48_step(unsigned short *xi, unsigned short *lc)
{
	uint64_t a, x;
	x = xi[0] | xi[1]<<16 | xi[2]+0ULL<<32;
	a = lc[0] | lc[1]<<16 | lc[2]+0ULL<<32;
	x = a*x + lc[3];
	xi[0] = x;
	xi[1] = x>>16;
	xi[2] = x>>32;
	return x & 0xffffffffffffull;
}