From d8b82cad1b525bdcbfff88d218c7c45032e4a3af Mon Sep 17 00:00:00 2001 From: Joseph Myers Date: Sun, 6 May 2012 18:23:44 +0000 Subject: Fix exp10 inaccuracy and exceptions (bugs 13884, 13914). --- sysdeps/ieee754/ldbl-128ibm/e_exp10l.c | 46 ++++++++++++++++++++++++++++++++++ 1 file changed, 46 insertions(+) create mode 100644 sysdeps/ieee754/ldbl-128ibm/e_exp10l.c (limited to 'sysdeps/ieee754/ldbl-128ibm/e_exp10l.c') diff --git a/sysdeps/ieee754/ldbl-128ibm/e_exp10l.c b/sysdeps/ieee754/ldbl-128ibm/e_exp10l.c new file mode 100644 index 0000000..b19e6c7 --- /dev/null +++ b/sysdeps/ieee754/ldbl-128ibm/e_exp10l.c @@ -0,0 +1,46 @@ +/* Copyright (C) 2012 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + . */ + +#include +#include +#include + +static const long double log10_high = 0x2.4d763776aaa2cp0L; +static const long double log10_low = -0xf.a456a4a751f4b3d75c75c04c18p-56L; + +long double +__ieee754_exp10l (long double arg) +{ + union ibm_extended_long_double u; + long double arg_high, arg_low; + long double exp_high, exp_low; + + if (!__finitel (arg)) + return __ieee754_expl (arg); + if (arg < LDBL_MIN_10_EXP - LDBL_DIG - 10) + return LDBL_MIN * LDBL_MIN; + else if (arg > LDBL_MAX_10_EXP + 1) + return LDBL_MAX * LDBL_MAX; + + u.d = arg; + arg_high = u.dd[0]; + arg_low = u.dd[1]; + exp_high = arg_high * log10_high; + exp_low = arg_high * log10_low + arg_low * M_LN10l; + return __ieee754_expl (exp_high) * __ieee754_expl (exp_low); +} +strong_alias (__ieee754_exp10l, __exp10l_finite) -- cgit v1.1