projects / thirdparty / glibc.git / blame
| Commit | Line | Data |
|---|---|---|
| f7eac6eb RM |
1 | /* e_atanhf.c -- float version of e_atanh.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 | #if defined(LIBM_SCCS) && !defined(lint) | |
| 17 | static char rcsid[] = "$NetBSD: e_atanhf.c,v 1.4 1995/05/10 20:44:56 jtc Exp $"; | |
| 18 | #endif | |
| 19 | ||
| 20 | #include "math.h" | |
| 21 | #include "math_private.h" | |
| 22 | ||
| 23 | #ifdef __STDC__ | |
| 24 | static const float one = 1.0, huge = 1e30; | |
| 25 | #else | |
| 26 | static float one = 1.0, huge = 1e30; | |
| 27 | #endif | |
| 28 | ||
| 29 | #ifdef __STDC__ | |
| 30 | static const float zero = 0.0; | |
| 31 | #else | |
| 32 | static float zero = 0.0; | |
| 33 | #endif | |
| 34 | ||
| 35 | #ifdef __STDC__ | |
| 36 | float __ieee754_atanhf(float x) | |
| 37 | #else | |
| 38 | float __ieee754_atanhf(x) | |
| 39 | float x; | |
| 40 | #endif | |
| 41 | { | |
| 42 | float t; | |
| 43 | int32_t hx,ix; | |
| 44 | GET_FLOAT_WORD(hx,x); | |
| 45 | ix = hx&0x7fffffff; | |
| 46 | if (ix>0x3f800000) /* |x|>1 */ | |
| 47 | return (x-x)/(x-x); | |
| 48 | if(ix==0x3f800000) | |
| 49 | return x/zero; | |
| 50 | if(ix<0x31800000&&(huge+x)>zero) return x; /* x<2**-28 */ | |
| 51 | SET_FLOAT_WORD(x,ix); | |
| 52 | if(ix<0x3f000000) { /* x < 0.5 */ | |
| 53 | t = x+x; | |
| 54 | t = (float)0.5*__log1pf(t+t*x/(one-x)); | |
| 55 | } else | |
| 56 | t = (float)0.5*__log1pf((x+x)/(one-x)); | |
| 57 | if(hx>=0) return t; else return -t; | |
| 58 | } |