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 #include "math.h"
18 #include "math_private.h"
19
20 float
hypotf(float x,float y)21 hypotf(float x, float y)
22 {
23 float a,b,t1,t2,y1,y2,w;
24 int32_t j,k,ha,hb;
25
26 GET_FLOAT_WORD(ha,x);
27 ha &= 0x7fffffff;
28 GET_FLOAT_WORD(hb,y);
29 hb &= 0x7fffffff;
30 if(hb > ha) {a=y;b=x;j=ha; ha=hb;hb=j;} else {a=x;b=y;}
31 a = fabsf(a);
32 b = fabsf(b);
33 if((ha-hb)>0xf000000) {return a+b;} /* x/y > 2**30 */
34 k=0;
35 if(ha > 0x58800000) { /* a>2**50 */
36 if(ha >= 0x7f800000) { /* Inf or NaN */
37 /* Use original arg order iff result is NaN; quieten sNaNs. */
38 w = fabsl(x+0.0L)-fabsf(y+0);
39 if(ha == 0x7f800000) w = a;
40 if(hb == 0x7f800000) w = b;
41 return w;
42 }
43 /* scale a and b by 2**-68 */
44 ha -= 0x22000000; hb -= 0x22000000; k += 68;
45 SET_FLOAT_WORD(a,ha);
46 SET_FLOAT_WORD(b,hb);
47 }
48 if(hb < 0x26800000) { /* b < 2**-50 */
49 if(hb <= 0x007fffff) { /* subnormal b or 0 */
50 if(hb==0) return a;
51 SET_FLOAT_WORD(t1,0x7e800000); /* t1=2^126 */
52 b *= t1;
53 a *= t1;
54 k -= 126;
55 } else { /* scale a and b by 2^68 */
56 ha += 0x22000000; /* a *= 2^68 */
57 hb += 0x22000000; /* b *= 2^68 */
58 k -= 68;
59 SET_FLOAT_WORD(a,ha);
60 SET_FLOAT_WORD(b,hb);
61 }
62 }
63 /* medium size a and b */
64 w = a-b;
65 if (w>b) {
66 SET_FLOAT_WORD(t1,ha&0xfffff000);
67 t2 = a-t1;
68 w = sqrtf(t1*t1-(b*(-b)-t2*(a+t1)));
69 } else {
70 a = a+a;
71 SET_FLOAT_WORD(y1,hb&0xfffff000);
72 y2 = b - y1;
73 SET_FLOAT_WORD(t1,(ha+0x00800000)&0xfffff000);
74 t2 = a - t1;
75 w = sqrtf(t1*y1-(w*(-w)-(t1*y2+t2*b)));
76 }
77 if(k!=0) {
78 SET_FLOAT_WORD(t1,(127+k)<<23);
79 return t1*w;
80 } else return w;
81 }
82