1 /* e_asinf.c -- float version of e_asin.c.
2 * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
6 * ====================================================
7 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
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
13 * ====================================================
17 #include "math_private.h"
20 one = 1.0000000000e+00, /* 0x3F800000 */
22 pio2_hi = 1.5707962513e+00, /* 0x3fc90fda */
23 pio2_lo = 7.5497894159e-08, /* 0x33a22168 */
24 pio4_hi = 7.8539818525e-01, /* 0x3f490fdb */
25 /* coefficient for R(x^2) */
26 pS0 = 1.6666667163e-01, /* 0x3e2aaaab */
27 pS1 = -3.2556581497e-01, /* 0xbea6b090 */
28 pS2 = 2.0121252537e-01, /* 0x3e4e0aa8 */
29 pS3 = -4.0055535734e-02, /* 0xbd241146 */
30 pS4 = 7.9153501429e-04, /* 0x3a4f7f04 */
31 pS5 = 3.4793309169e-05, /* 0x3811ef08 */
32 qS1 = -2.4033949375e+00, /* 0xc019d139 */
33 qS2 = 2.0209457874e+00, /* 0x4001572d */
34 qS3 = -6.8828397989e-01, /* 0xbf303361 */
35 qS4 = 7.7038154006e-02; /* 0x3d9dc62e */
40 float t=0.0,w,p,q,c,r,s;
45 /* asin(1)=+-pi/2 with inexact */
46 return x*pio2_hi+x*pio2_lo;
47 } else if(ix> 0x3f800000) { /* |x|>= 1 */
48 return (x-x)/(x-x); /* asin(|x|>1) is NaN */
49 } else if (ix<0x3f000000) { /* |x|<0.5 */
50 if(ix<0x32000000) { /* if |x| < 2**-27 */
51 if(huge+x>one) return x;/* return x with inexact if x!=0*/
54 p = t*(pS0+t*(pS1+t*(pS2+t*(pS3+t*(pS4+t*pS5)))));
55 q = one+t*(qS1+t*(qS2+t*(qS3+t*qS4)));
62 p = t*(pS0+t*(pS1+t*(pS2+t*(pS3+t*(pS4+t*pS5)))));
63 q = one+t*(qS1+t*(qS2+t*(qS3+t*qS4)));
65 if(ix>=0x3F79999A) { /* if |x| > 0.975 */
67 t = pio2_hi-((float)2.0*(s+s*w)-pio2_lo);
72 SET_FLOAT_WORD(w,iw&0xfffff000);
75 p = (float)2.0*s*r-(pio2_lo-(float)2.0*c);
76 q = pio4_hi-(float)2.0*w;
79 if(hx>0) return t; else return -t;