1 /* e_asinf.c -- float version of e_asin.c.
2 * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
4 * $FreeBSD: src/lib/msun/src/e_asinf.c,v 1.7 1999/08/28 00:06:28 peter Exp $
5 * $DragonFly: src/lib/msun/src/Attic/e_asinf.c,v 1.2 2003/06/17 04:26:52 dillon Exp $
9 * ====================================================
10 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
12 * Developed at SunPro, a Sun Microsystems, Inc. business.
13 * Permission to use, copy, modify, and distribute this
14 * software is freely granted, provided that this notice
16 * ====================================================
20 #include "math_private.h"
27 one = 1.0000000000e+00, /* 0x3F800000 */
29 pio2_hi = 1.5707962513e+00, /* 0x3fc90fda */
30 pio2_lo = 7.5497894159e-08, /* 0x33a22168 */
31 pio4_hi = 7.8539818525e-01, /* 0x3f490fdb */
32 /* coefficient for R(x^2) */
33 pS0 = 1.6666667163e-01, /* 0x3e2aaaab */
34 pS1 = -3.2556581497e-01, /* 0xbea6b090 */
35 pS2 = 2.0121252537e-01, /* 0x3e4e0aa8 */
36 pS3 = -4.0055535734e-02, /* 0xbd241146 */
37 pS4 = 7.9153501429e-04, /* 0x3a4f7f04 */
38 pS5 = 3.4793309169e-05, /* 0x3811ef08 */
39 qS1 = -2.4033949375e+00, /* 0xc019d139 */
40 qS2 = 2.0209457874e+00, /* 0x4001572d */
41 qS3 = -6.8828397989e-01, /* 0xbf303361 */
42 qS4 = 7.7038154006e-02; /* 0x3d9dc62e */
45 float __ieee754_asinf(float x)
47 float __ieee754_asinf(x)
51 float t=0.0,w,p,q,c,r,s;
56 /* asin(1)=+-pi/2 with inexact */
57 return x*pio2_hi+x*pio2_lo;
58 } else if(ix> 0x3f800000) { /* |x|>= 1 */
59 return (x-x)/(x-x); /* asin(|x|>1) is NaN */
60 } else if (ix<0x3f000000) { /* |x|<0.5 */
61 if(ix<0x32000000) { /* if |x| < 2**-27 */
62 if(huge+x>one) return x;/* return x with inexact if x!=0*/
65 p = t*(pS0+t*(pS1+t*(pS2+t*(pS3+t*(pS4+t*pS5)))));
66 q = one+t*(qS1+t*(qS2+t*(qS3+t*qS4)));
73 p = t*(pS0+t*(pS1+t*(pS2+t*(pS3+t*(pS4+t*pS5)))));
74 q = one+t*(qS1+t*(qS2+t*(qS3+t*qS4)));
75 s = __ieee754_sqrtf(t);
76 if(ix>=0x3F79999A) { /* if |x| > 0.975 */
78 t = pio2_hi-((float)2.0*(s+s*w)-pio2_lo);
83 SET_FLOAT_WORD(w,iw&0xfffff000);
86 p = (float)2.0*s*r-(pio2_lo-(float)2.0*c);
87 q = pio4_hi-(float)2.0*w;
90 if(hx>0) return t; else return -t;