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Power 6/32 Unix version 1.21

/*
 *	"@(#)z_sqrt.c	1.1"
 */

#include "complex"

/* THIS IS BASED ON THE TAHOE FP REPRESENTATION */
#include <FP.h>

z_sqrt(r, z)
dcomplex *r, *z;
{
double mag, sqrt(), zabs();

if( (mag = zabs(z->dreal, z->dimag)) == 0.)
	r->dreal = r->dimag = 0.;
else if(z->dreal > 0)
	{
	r->dreal = sqrt(0.5 * (mag + z->dreal) );
	r->dimag = z->dimag / r->dreal / 2;
	}
else
	{
	r->dimag = sqrt(0.5 * (mag - z->dreal) );
	if(z->dimag < 0)
		*((long int *)&r->dimag) ^= SIGN_BIT;
	r->dreal = z->dimag / r->dimag / 2;
	}
}

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