git: 9front

ref: bc7d74f09b53c39ada4e73ce73c01c6c0928f9f4
dir: /sys/src/cmd/unix/drawterm/libc/frand.c/

View raw version 
#include	<u.h>
#include	<libc.h>

#define	MASK	0x7fffffffL
#define	NORM	(1.0/(1.0+MASK))

double
frand(void)
{
	double x;

	do {
		x = lrand() * NORM;
		x = (x + lrand()) * NORM;
	} while(x >= 1);
	return x;
}