e_hypotf.c - vx32 - Local 9vx git repository for patches.
(HTM) git clone git://r-36.net/vx32
(DIR) Log
(DIR) Files
(DIR) Refs
---
e_hypotf.c (2242B)
---
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 #ifndef lint
17 static char rcsid[] = "$FreeBSD: src/lib/msun/src/e_hypotf.c,v 1.9 2002/05/28 18:15:03 alfred Exp $";
18 #endif
19
20 #include "math.h"
21 #include "math_private.h"
22
23 float
24 __ieee754_hypotf(float x, float y)
25 {
26 float a=x,b=y,t1,t2,y1,y2,w;
27 int32_t j,k,ha,hb;
28
29 GET_FLOAT_WORD(ha,x);
30 ha &= 0x7fffffff;
31 GET_FLOAT_WORD(hb,y);
32 hb &= 0x7fffffff;
33 if(hb > ha) {a=y;b=x;j=ha; ha=hb;hb=j;} else {a=x;b=y;}
34 SET_FLOAT_WORD(a,ha); /* a <- |a| */
35 SET_FLOAT_WORD(b,hb); /* b <- |b| */
36 if((ha-hb)>0xf000000) {return a+b;} /* x/y > 2**30 */
37 k=0;
38 if(ha > 0x58800000) { /* a>2**50 */
39 if(ha >= 0x7f800000) { /* Inf or NaN */
40 w = a+b; /* for sNaN */
41 if(ha == 0x7f800000) w = a;
42 if(hb == 0x7f800000) w = b;
43 return w;
44 }
45 /* scale a and b by 2**-68 */
46 ha -= 0x22000000; hb -= 0x22000000; k += 68;
47 SET_FLOAT_WORD(a,ha);
48 SET_FLOAT_WORD(b,hb);
49 }
50 if(hb < 0x26800000) { /* b < 2**-50 */
51 if(hb <= 0x007fffff) { /* subnormal b or 0 */
52 if(hb==0) return a;
53 SET_FLOAT_WORD(t1,0x7e800000); /* t1=2^126 */
54 b *= t1;
55 a *= t1;
56 k -= 126;
57 } else { /* scale a and b by 2^68 */
58 ha += 0x22000000; /* a *= 2^68 */
59 hb += 0x22000000; /* b *= 2^68 */
60 k -= 68;
61 SET_FLOAT_WORD(a,ha);
62 SET_FLOAT_WORD(b,hb);
63 }
64 }
65 /* medium size a and b */
66 w = a-b;
67 if (w>b) {
68 SET_FLOAT_WORD(t1,ha&0xfffff000);
69 t2 = a-t1;
70 w = __ieee754_sqrtf(t1*t1-(b*(-b)-t2*(a+t1)));
71 } else {
72 a = a+a;
73 SET_FLOAT_WORD(y1,hb&0xfffff000);
74 y2 = b - y1;
75 SET_FLOAT_WORD(t1,ha+0x00800000);
76 t2 = a - t1;
77 w = __ieee754_sqrtf(t1*y1-(w*(-w)-(t1*y2+t2*b)));
78 }
79 if(k!=0) {
80 SET_FLOAT_WORD(t1,0x3f800000+(k<<23));
81 return t1*w;
82 } else return w;
83 }