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,b,t1,t2,y1,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	a = fabsf(a);
31	b = fabsf(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	       /* Use original arg order iff result is NaN; quieten sNaNs. */
37	       w = fabsl(x+0.0L)-fabsf(y+0);
38	       if(ha == 0x7f800000) w = a;
39	       if(hb == 0x7f800000) w = b;
40	       return w;
41	   }
42	   /* scale a and b by 2**-68 */
43	   ha -= 0x22000000; hb -= 0x22000000;	k += 68;
44	   SET_FLOAT_WORD(a,ha);
45	   SET_FLOAT_WORD(b,hb);
46	}
47	if(hb < 0x26800000) {	/* b < 2**-50 */
48	    if(hb <= 0x007fffff) {	/* subnormal b or 0 */
49	        if(hb==0) return a;
50		SET_FLOAT_WORD(t1,0x7e800000);	/* t1=2^126 */
51		b *= t1;
52		a *= t1;
53		k -= 126;
54	    } else {		/* scale a and b by 2^68 */
55	        ha += 0x22000000; 	/* a *= 2^68 */
56		hb += 0x22000000;	/* b *= 2^68 */
57		k -= 68;
58		SET_FLOAT_WORD(a,ha);
59		SET_FLOAT_WORD(b,hb);
60	    }
61	}
62    /* medium size a and b */
63	w = a-b;
64	if (w>b) {
65	    SET_FLOAT_WORD(t1,ha&0xfffff000);
66	    t2 = a-t1;
67	    w  = sqrtf(t1*t1-(b*(-b)-t2*(a+t1)));
68	} else {
69	    a  = a+a;
70	    SET_FLOAT_WORD(y1,hb&0xfffff000);
71	    y2 = b - y1;
72	    SET_FLOAT_WORD(t1,(ha+0x00800000)&0xfffff000);
73	    t2 = a - t1;
74	    w  = sqrtf(t1*y1-(w*(-w)-(t1*y2+t2*b)));
75	}
76	if(k!=0) {
77	    SET_FLOAT_WORD(t1,(127+k)<<23);
78	    return t1*w;
79	} else return w;
80}
81