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Diffstat (limited to 'lib/msun/src/s_asinhl.c')
-rw-r--r-- | lib/msun/src/s_asinhl.c | 91 |
1 files changed, 91 insertions, 0 deletions
diff --git a/lib/msun/src/s_asinhl.c b/lib/msun/src/s_asinhl.c new file mode 100644 index 0000000..ba28f59 --- /dev/null +++ b/lib/msun/src/s_asinhl.c @@ -0,0 +1,91 @@ +/* from: FreeBSD: head/lib/msun/src/e_acosh.c 176451 2008-02-22 02:30:36Z das */ + +/* @(#)s_asinh.c 5.1 93/09/24 */ +/* + * ==================================================== + * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. + * + * Developed at SunPro, a Sun Microsystems, Inc. business. + * Permission to use, copy, modify, and distribute this + * software is freely granted, provided that this notice + * is preserved. + * ==================================================== + */ + +#include <sys/cdefs.h> +__FBSDID("$FreeBSD$"); + +/* + * See s_asinh.c for complete comments. + * + * Converted to long double by David Schultz <das@FreeBSD.ORG> and + * Bruce D. Evans. + */ + +#include <float.h> +#ifdef __i386__ +#include <ieeefp.h> +#endif + +#include "fpmath.h" +#include "math.h" +#include "math_private.h" + +/* EXP_LARGE is the threshold above which we use asinh(x) ~= log(2x). */ +/* EXP_TINY is the threshold below which we use asinh(x) ~= x. */ +#if LDBL_MANT_DIG == 64 +#define EXP_LARGE 34 +#define EXP_TINY -34 +#elif LDBL_MANT_DIG == 113 +#define EXP_LARGE 58 +#define EXP_TINY -58 +#else +#error "Unsupported long double format" +#endif + +#if LDBL_MAX_EXP != 0x4000 +/* We also require the usual expsign encoding. */ +#error "Unsupported long double format" +#endif + +#define BIAS (LDBL_MAX_EXP - 1) + +static const double +one = 1.00000000000000000000e+00, /* 0x3FF00000, 0x00000000 */ +huge= 1.00000000000000000000e+300; + +#if LDBL_MANT_DIG == 64 +static const union IEEEl2bits +u_ln2 = LD80C(0xb17217f7d1cf79ac, -1, 6.93147180559945309417e-1L); +#define ln2 u_ln2.e +#elif LDBL_MANT_DIG == 113 +static const long double +ln2 = 6.93147180559945309417232121458176568e-1L; /* 0x162e42fefa39ef35793c7673007e6.0p-113 */ +#else +#error "Unsupported long double format" +#endif + +long double +asinhl(long double x) +{ + long double t, w; + uint16_t hx, ix; + + ENTERI(); + GET_LDBL_EXPSIGN(hx, x); + ix = hx & 0x7fff; + if (ix >= 0x7fff) RETURNI(x+x); /* x is inf, NaN or misnormal */ + if (ix < BIAS + EXP_TINY) { /* |x| < TINY, or misnormal */ + if (huge + x > one) RETURNI(x); /* return x inexact except 0 */ + } + if (ix >= BIAS + EXP_LARGE) { /* |x| >= LARGE, or misnormal */ + w = logl(fabsl(x))+ln2; + } else if (ix >= 0x4000) { /* LARGE > |x| >= 2.0, or misnormal */ + t = fabsl(x); + w = logl(2.0*t+one/(sqrtl(x*x+one)+t)); + } else { /* 2.0 > |x| >= TINY, or misnormal */ + t = x*x; + w =log1pl(fabsl(x)+t/(one+sqrtl(one+t))); + } + RETURNI((hx & 0x8000) == 0 ? w : -w); +} |