projects / thirdparty / glibc.git / blame
| Commit | Line | Data |
|---|---|---|
| f7eac6eb RM |
1 | /* e_acoshf.c -- float version of e_acosh.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 | |
| 0ac5ae23 | 11 | * software is freely granted, provided that this notice |
| f7eac6eb RM |
12 | * is preserved. |
| 13 | * ==================================================== | |
| 14 | */ | |
| 15 | ||
| 16 | #if defined(LIBM_SCCS) && !defined(lint) | |
| 17 | static char rcsid[] = "$NetBSD: e_acoshf.c,v 1.5 1995/05/12 04:57:20 jtc Exp $"; | |
| 18 | #endif | |
| 19 | ||
| 20 | #include "math.h" | |
| 21 | #include "math_private.h" | |
| 22 | ||
| 23 | #ifdef __STDC__ | |
| 0ac5ae23 | 24 | static const float |
| f7eac6eb | 25 | #else |
| 0ac5ae23 | 26 | static float |
| f7eac6eb RM |
27 | #endif |
| 28 | one = 1.0, | |
| 29 | ln2 = 6.9314718246e-01; /* 0x3f317218 */ | |
| 30 | ||
| 31 | #ifdef __STDC__ | |
| 32 | float __ieee754_acoshf(float x) | |
| 33 | #else | |
| 34 | float __ieee754_acoshf(x) | |
| 35 | float x; | |
| 36 | #endif | |
| 0ac5ae23 | 37 | { |
| f7eac6eb RM |
38 | float t; |
| 39 | int32_t hx; | |
| 40 | GET_FLOAT_WORD(hx,x); | |
| 41 | if(hx<0x3f800000) { /* x < 1 */ | |
| 42 | return (x-x)/(x-x); | |
| 43 | } else if(hx >=0x4d800000) { /* x > 2**28 */ | |
| 44 | if(hx >=0x7f800000) { /* x is inf of NaN */ | |
| 0ac5ae23 UD |
45 | return x+x; |
| 46 | } else | |
| f7eac6eb RM |
47 | return __ieee754_logf(x)+ln2; /* acosh(huge)=log(2x) */ |
| 48 | } else if (hx==0x3f800000) { | |
| 49 | return 0.0; /* acosh(1) = 0 */ | |
| 50 | } else if (hx > 0x40000000) { /* 2**28 > x > 2 */ | |
| 51 | t=x*x; | |
| 52 | return __ieee754_logf((float)2.0*x-one/(x+__ieee754_sqrtf(t-one))); | |
| 53 | } else { /* 1<x<2 */ | |
| 54 | t = x-one; | |
| 55 | return __log1pf(t+__sqrtf((float)2.0*t+t*t)); | |
| 56 | } | |
| 57 | } | |
| 0ac5ae23 | 58 | strong_alias (__ieee754_acoshf, __acoshf_finite) |