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 "math.h"
17#include "math_private.h"
18
19float
20hypotf(float x, float y)
21{
22	float a=x,b=y,t1,t2,yy1,y2,w;
23	int32_t j,k,ha,hb;
24
25	GET_FLOAT_WORD(ha,x);
26	ha &= 0x7fffffff;
27	GET_FLOAT_WORD(hb,y);
28	hb &= 0x7fffffff;
29	if(hb > ha) {a=y;b=x;j=ha; ha=hb;hb=j;} else {a=x;b=y;}
30	SET_FLOAT_WORD(a,ha);	/* a <- |a| */
31	SET_FLOAT_WORD(b,hb);	/* b <- |b| */
32	if((ha-hb)>0xf000000) {return a+b;} /* x/y > 2**30 */
33	k=0;
34	if(ha > 0x58800000) {	/* a>2**50 */
35	   if(ha >= 0x7f800000) {	/* Inf or NaN */
36	       w = a+b;			/* for sNaN */
37	       if(ha == 0x7f800000) w = a;
38	       if(hb == 0x7f800000) w = b;
39	       return w;
40	   }
41	   /* scale a and b by 2**-68 */
42	   ha -= 0x22000000; hb -= 0x22000000;	k += 68;
43	   SET_FLOAT_WORD(a,ha);
44	   SET_FLOAT_WORD(b,hb);
45	}
46	if(hb < 0x26800000) {	/* b < 2**-50 */
47	    if(hb <= 0x007fffff) {	/* subnormal b or 0 */
48	        if(hb==0) return a;
49		SET_FLOAT_WORD(t1,0x7e800000);	/* t1=2^126 */
50		b *= t1;
51		a *= t1;
52		k -= 126;
53	    } else {		/* scale a and b by 2^68 */
54	        ha += 0x22000000; 	/* a *= 2^68 */
55		hb += 0x22000000;	/* b *= 2^68 */
56		k -= 68;
57		SET_FLOAT_WORD(a,ha);
58		SET_FLOAT_WORD(b,hb);
59	    }
60	}
61    /* medium size a and b */
62	w = a-b;
63	if (w>b) {
64	    SET_FLOAT_WORD(t1,ha&0xfffff000);
65	    t2 = a-t1;
66	    w  = sqrtf(t1*t1-(b*(-b)-t2*(a+t1)));
67	} else {
68	    a  = a+a;
69	    SET_FLOAT_WORD(yy1,hb&0xfffff000);
70	    y2 = b - yy1;
71	    SET_FLOAT_WORD(t1,ha+0x00800000);
72	    t2 = a - t1;
73	    w  = sqrtf(t1*yy1-(w*(-w)-(t1*y2+t2*b)));
74	}
75	if(k!=0) {
76	    SET_FLOAT_WORD(t1,0x3f800000+(k<<23));
77	    return t1*w;
78	} else return w;
79}
80DEF_STD(hypotf);
81