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#if defined(LIBM_SCCS) && !defined(lint)
17static char rcsid[] = "$NetBSD: e_hypotf.c,v 1.5 1995/05/12 04:57:30 jtc Exp $";
18#endif
19
20#include "math.h"
21#include "math_private.h"
22
23#ifdef __STDC__
24	float __ieee754_hypotf(float x, float y)
25#else
26	float __ieee754_hypot(x,y)
27	float x, y;
28#endif
29{
30	float a,b,t1,t2,y1,y2,w;
31	int32_t j,k,ha,hb;
32
33	GET_FLOAT_WORD(ha,x);
34	ha &= 0x7fffffff;
35	GET_FLOAT_WORD(hb,y);
36	hb &= 0x7fffffff;
37	if(hb > ha) {a=y;b=x;j=ha; ha=hb;hb=j;} else {a=x;b=y;}
38	SET_FLOAT_WORD(a,ha);	/* a <- |a| */
39	SET_FLOAT_WORD(b,hb);	/* b <- |b| */
40	if((ha-hb)>0xf000000) {return a+b;} /* x/y > 2**30 */
41	k=0;
42	if(ha > 0x58800000) {	/* a>2**50 */
43	   if(ha >= 0x7f800000) {	/* Inf or NaN */
44	       w = a+b;			/* for sNaN */
45	       if(ha == 0x7f800000) w = a;
46	       if(hb == 0x7f800000) w = b;
47	       return w;
48	   }
49	   /* scale a and b by 2**-60 */
50	   ha -= 0x5d800000; hb -= 0x5d800000;	k += 60;
51	   SET_FLOAT_WORD(a,ha);
52	   SET_FLOAT_WORD(b,hb);
53	}
54	if(hb < 0x26800000) {	/* b < 2**-50 */
55	    if(hb <= 0x007fffff) {	/* subnormal b or 0 */
56	        if(hb==0) return a;
57		SET_FLOAT_WORD(t1,0x3f000000);	/* t1=2^126 */
58		b *= t1;
59		a *= t1;
60		k -= 126;
61	    } else {		/* scale a and b by 2^60 */
62	        ha += 0x5d800000; 	/* a *= 2^60 */
63		hb += 0x5d800000;	/* b *= 2^60 */
64		k -= 60;
65		SET_FLOAT_WORD(a,ha);
66		SET_FLOAT_WORD(b,hb);
67	    }
68	}
69    /* medium size a and b */
70	w = a-b;
71	if (w>b) {
72	    SET_FLOAT_WORD(t1,ha&0xfffff000);
73	    t2 = a-t1;
74	    w  = __ieee754_sqrtf(t1*t1-(b*(-b)-t2*(a+t1)));
75	} else {
76	    a  = a+a;
77	    SET_FLOAT_WORD(y1,hb&0xfffff000);
78	    y2 = b - y1;
79	    SET_FLOAT_WORD(t1,ha+0x00800000);
80	    t2 = a - t1;
81	    w  = __ieee754_sqrtf(t1*y1-(w*(-w)-(t1*y2+t2*b)));
82	}
83	if(k!=0) {
84	    SET_FLOAT_WORD(t1,0x3f800000+(k<<23));
85	    return t1*w;
86	} else return w;
87}
88