git: 9front

ref: 97b933150299e6a61b24d366c069c7b85f7a9927
dir: /sys/src/libc/port/frand.c/

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#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;
}