1/* e_hypotf.c -- float version of e_hypot.c.
2 * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
3 */
4
5/*
6 * ====================================================
7 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
8 *
9 * Developed at SunPro, a Sun Microsystems, Inc. business.
10 * Permission to use, copy, modify, and distribute this
11 * software is freely granted, provided that this notice
12 * is preserved.
13 * ====================================================
14 */
15
16#include <sys/cdefs.h>
17#if defined(LIBM_SCCS) && !defined(lint)
18__RCSID("$NetBSD: e_hypotf.c,v 1.10 2016/01/24 20:34:30 gson Exp $");
19#endif
20
21#include "math.h"
22#include "math_private.h"
23
24float
25__ieee754_hypotf(float x, float y)
26{
27	float a=x,b=y,t1,t2,yy1,y2,w;
28	int32_t j,k,ha,hb;
29
30	GET_FLOAT_WORD(ha,x);
31	ha &= 0x7fffffff;
32	GET_FLOAT_WORD(hb,y);
33	hb &= 0x7fffffff;
34	if(hb > ha) {a=y;b=x;j=ha; ha=hb;hb=j;} else {a=x;b=y;}
35	SET_FLOAT_WORD(a,ha);	/* a <- |a| */
36	SET_FLOAT_WORD(b,hb);	/* b <- |b| */
37	if((ha-hb)>0xf000000) {return a+b;} /* x/y > 2**30 */
38	k=0;
39	if(ha > 0x58800000) {	/* a>2**50 */
40	   if(ha >= 0x7f800000) {	/* Inf or NaN */
41	       w = a+b;			/* for sNaN */
42	       if(ha == 0x7f800000) w = a;
43	       if(hb == 0x7f800000) w = b;
44	       return w;
45	   }
46	   /* scale a and b by 2**-68 */
47	   ha -= 0x22000000; hb -= 0x22000000;	k += 68;
48	   SET_FLOAT_WORD(a,ha);
49	   SET_FLOAT_WORD(b,hb);
50	}
51	if(hb < 0x26800000) {	/* b < 2**-50 */
52	    if(hb <= 0x007fffff) {	/* subnormal b or 0 */
53	        if(hb==0) return a;
54		SET_FLOAT_WORD(t1,0x7e800000);	/* t1=2^126 */
55		b *= t1;
56		a *= t1;
57		k -= 126;
58	    } else {		/* scale a and b by 2^68 */
59	        ha += 0x22000000; 	/* a *= 2^68 */
60		hb += 0x22000000;	/* b *= 2^68 */
61		k -= 68;
62		SET_FLOAT_WORD(a,ha);
63		SET_FLOAT_WORD(b,hb);
64	    }
65	}
66    /* medium size a and b */
67	w = a-b;
68	if (w>b) {
69	    SET_FLOAT_WORD(t1,ha&0xfffff000);
70	    t2 = a-t1;
71	    w  = __ieee754_sqrtf(t1*t1-(b*(-b)-t2*(a+t1)));
72	} else {
73	    a  = a+a;
74	    SET_FLOAT_WORD(yy1,hb&0xfffff000);
75	    y2 = b - yy1;
76	    SET_FLOAT_WORD(t1,ha+0x00800000);
77	    t2 = a - t1;
78	    w  = __ieee754_sqrtf(t1*yy1-(w*(-w)-(t1*y2+t2*b)));
79	}
80	if(k!=0) {
81	    SET_FLOAT_WORD(t1,0x3f800000+(k<<23));
82	    return t1*w;
83	} else return w;
84}
85