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Revision 1.10, Sun Jan 24 20:34:30 2016 UTC (8 years, 2 months ago) by gson
Branch: MAIN
CVS Tags: prg-localcount2-base3, prg-localcount2-base2, prg-localcount2-base1, prg-localcount2-base, prg-localcount2, phil-wifi-base, phil-wifi-20200421, phil-wifi-20200411, phil-wifi-20200406, phil-wifi-20191119, phil-wifi-20190609, phil-wifi, pgoyette-localcount-base, pgoyette-localcount-20170426, pgoyette-localcount-20170320, pgoyette-localcount-20170107, pgoyette-localcount-20161104, pgoyette-localcount-20160806, pgoyette-localcount-20160726, pgoyette-localcount, pgoyette-compat-merge-20190127, pgoyette-compat-base, pgoyette-compat-20190127, pgoyette-compat-20190118, pgoyette-compat-1226, pgoyette-compat-1126, pgoyette-compat-1020, pgoyette-compat-0930, pgoyette-compat-0906, pgoyette-compat-0728, pgoyette-compat-0625, pgoyette-compat-0521, pgoyette-compat-0502, pgoyette-compat-0422, pgoyette-compat-0415, pgoyette-compat-0407, pgoyette-compat-0330, pgoyette-compat-0322, pgoyette-compat-0315, pgoyette-compat, perseant-stdc-iso10646-base, perseant-stdc-iso10646, netbsd-9-base, netbsd-9-3-RELEASE, netbsd-9-2-RELEASE, netbsd-9-1-RELEASE, netbsd-9-0-RELEASE, netbsd-9-0-RC2, netbsd-9-0-RC1, netbsd-9, netbsd-8-base, netbsd-8-2-RELEASE, netbsd-8-1-RELEASE, netbsd-8-1-RC1, netbsd-8-0-RELEASE, netbsd-8-0-RC2, netbsd-8-0-RC1, netbsd-8, netbsd-10-base, netbsd-10-0-RELEASE, netbsd-10-0-RC6, netbsd-10-0-RC5, netbsd-10-0-RC4, netbsd-10-0-RC3, netbsd-10-0-RC2, netbsd-10-0-RC1, netbsd-10, matt-nb8-mediatek-base, matt-nb8-mediatek, localcount-20160914, is-mlppp-base, is-mlppp, cjep_sun2x-base1, cjep_sun2x-base, cjep_sun2x, cjep_staticlib_x-base1, cjep_staticlib_x-base, cjep_staticlib_x, bouyer-socketcan-base1, bouyer-socketcan-base, bouyer-socketcan, HEAD
Changes since 1.9: +8 -8 lines 

Fix incorrect magic numbers in scaling.  From FreeBSD commit 23397, by
way of Rin Okuyama.  Fixes PR lib/50698.

/* e_hypotf.c -- float version of e_hypot.c.
 * Conversion to float 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.
 * ====================================================
 */

#include <sys/cdefs.h>
#if defined(LIBM_SCCS) && !defined(lint)
__RCSID("$NetBSD: e_hypotf.c,v 1.10 2016/01/24 20:34:30 gson Exp $");
#endif

#include "math.h"
#include "math_private.h"

float
__ieee754_hypotf(float x, float y)
{
	float a=x,b=y,t1,t2,yy1,y2,w;
	int32_t j,k,ha,hb;

	GET_FLOAT_WORD(ha,x);
	ha &= 0x7fffffff;
	GET_FLOAT_WORD(hb,y);
	hb &= 0x7fffffff;
	if(hb > ha) {a=y;b=x;j=ha; ha=hb;hb=j;} else {a=x;b=y;}
	SET_FLOAT_WORD(a,ha);	/* a <- |a| */
	SET_FLOAT_WORD(b,hb);	/* b <- |b| */
	if((ha-hb)>0xf000000) {return a+b;} /* x/y > 2**30 */
	k=0;
	if(ha > 0x58800000) {	/* a>2**50 */
	   if(ha >= 0x7f800000) {	/* Inf or NaN */
	       w = a+b;			/* for sNaN */
	       if(ha == 0x7f800000) w = a;
	       if(hb == 0x7f800000) w = b;
	       return w;
	   }
	   /* scale a and b by 2**-68 */
	   ha -= 0x22000000; hb -= 0x22000000;	k += 68;
	   SET_FLOAT_WORD(a,ha);
	   SET_FLOAT_WORD(b,hb);
	}
	if(hb < 0x26800000) {	/* b < 2**-50 */
	    if(hb <= 0x007fffff) {	/* subnormal b or 0 */
	        if(hb==0) return a;
		SET_FLOAT_WORD(t1,0x7e800000);	/* t1=2^126 */
		b *= t1;
		a *= t1;
		k -= 126;
	    } else {		/* scale a and b by 2^68 */
	        ha += 0x22000000; 	/* a *= 2^68 */
		hb += 0x22000000;	/* b *= 2^68 */
		k -= 68;
		SET_FLOAT_WORD(a,ha);
		SET_FLOAT_WORD(b,hb);
	    }
	}
    /* medium size a and b */
	w = a-b;
	if (w>b) {
	    SET_FLOAT_WORD(t1,ha&0xfffff000);
	    t2 = a-t1;
	    w  = __ieee754_sqrtf(t1*t1-(b*(-b)-t2*(a+t1)));
	} else {
	    a  = a+a;
	    SET_FLOAT_WORD(yy1,hb&0xfffff000);
	    y2 = b - yy1;
	    SET_FLOAT_WORD(t1,ha+0x00800000);
	    t2 = a - t1;
	    w  = __ieee754_sqrtf(t1*yy1-(w*(-w)-(t1*y2+t2*b)));
	}
	if(k!=0) {
	    SET_FLOAT_WORD(t1,0x3f800000+(k<<23));
	    return t1*w;
	} else return w;
}