1 | /* s_asinhl.c -- long double version of s_asinh.c. |
2 | * Conversion to long double by Ulrich Drepper, |
3 | * Cygnus Support, drepper@cygnus.com. |
4 | */ |
5 | |
6 | /* |
7 | * ==================================================== |
8 | * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. |
9 | * |
10 | * Developed at SunPro, a Sun Microsystems, Inc. business. |
11 | * Permission to use, copy, modify, and distribute this |
12 | * software is freely granted, provided that this notice |
13 | * is preserved. |
14 | * ==================================================== |
15 | */ |
16 | |
17 | #if defined(LIBM_SCCS) && !defined(lint) |
18 | static char rcsid[] = "$NetBSD: $" ; |
19 | #endif |
20 | |
21 | /* asinhl(x) |
22 | * Method : |
23 | * Based on |
24 | * asinhl(x) = signl(x) * logl [ |x| + sqrtl(x*x+1) ] |
25 | * we have |
26 | * asinhl(x) := x if 1+x*x=1, |
27 | * := signl(x)*(logl(x)+ln2)) for large |x|, else |
28 | * := signl(x)*logl(2|x|+1/(|x|+sqrtl(x*x+1))) if|x|>2, else |
29 | * := signl(x)*log1pl(|x| + x^2/(1 + sqrtl(1+x^2))) |
30 | */ |
31 | |
32 | #include <float.h> |
33 | #include <math.h> |
34 | #include <math_private.h> |
35 | #include <libm-alias-ldouble.h> |
36 | |
37 | static const long double |
38 | one = 1.000000000000000000000e+00L, /* 0x3FFF, 0x00000000, 0x00000000 */ |
39 | ln2 = 6.931471805599453094287e-01L, /* 0x3FFE, 0xB17217F7, 0xD1CF79AC */ |
40 | huge= 1.000000000000000000e+4900L; |
41 | |
42 | long double __asinhl(long double x) |
43 | { |
44 | long double t,w; |
45 | int32_t hx,ix; |
46 | GET_LDOUBLE_EXP(hx,x); |
47 | ix = hx&0x7fff; |
48 | if(__builtin_expect(ix< 0x3fde, 0)) { /* |x|<2**-34 */ |
49 | math_check_force_underflow (x); |
50 | if(huge+x>one) return x; /* return x inexact except 0 */ |
51 | } |
52 | if(__builtin_expect(ix>0x4020,0)) { /* |x| > 2**34 */ |
53 | if(ix==0x7fff) return x+x; /* x is inf or NaN */ |
54 | w = __ieee754_logl(fabsl(x))+ln2; |
55 | } else { |
56 | long double xa = fabsl(x); |
57 | if (ix>0x4000) { /* 2**34 > |x| > 2.0 */ |
58 | w = __ieee754_logl(2.0*xa+one/(__ieee754_sqrtl(xa*xa+one)+xa)); |
59 | } else { /* 2.0 > |x| > 2**-28 */ |
60 | t = xa*xa; |
61 | w =__log1pl(xa+t/(one+__ieee754_sqrtl(one+t))); |
62 | } |
63 | } |
64 | return __copysignl(w, x); |
65 | } |
66 | libm_alias_ldouble (__asinh, asinh) |
67 | |