e_sqrtf.cpp

/* See the import.pl script for potential modifications */
/* e_sqrtf.c -- Simple version of e_sqrt.c.
 * Conversion to Simple by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
 */

/*
 * ====================================================
 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
 *
 * Developed at SunPro, a Sun Microsystems, Inc. business.
 * Permission to use, copy, modify, and distribute this
 * software is freely granted, provided that this notice 
 * is preserved.
 * ====================================================
 */

#if defined(LIBM_SCCS) && !defined(lint)
static char rcsid[] = "$NetBSD: e_sqrtf.c,v 1.4f 1995/05/10 20:46:19 jtc Exp $";
#endif

#include "SMath.h"
#include "math_private.h"

namespace streflop_libm {
#ifdef __STDC__
	Simple __ieee754_sqrtf(Simple x)
#else
	Simple __ieee754_sqrtf(x)
	Simple x;
#endif
{
    float y = x;
    // Approximation
    uint32_t* i = (uint32_t*)&x;
    *i = (*i >> 1) + (127 << 22);
    // Newton-Raphson
    x = (x + y/x) / 2;
    x = (x + y/x) / 2;
    x = (x + y/x) / 2;
    return x;
}
}