1 /* Copyright (C) 2012-2021 Free Software Foundation, Inc. 2 This file is part of the GNU C Library. 3 4 The GNU C Library is free software; you can redistribute it and/or 5 modify it under the terms of the GNU Lesser General Public 6 License as published by the Free Software Foundation; either 7 version 2.1 of the License, or (at your option) any later version. 8 9 The GNU C Library is distributed in the hope that it will be useful, 10 but WITHOUT ANY WARRANTY; without even the implied warranty of 11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 12 Lesser General Public License for more details. 13 14 You should have received a copy of the GNU Lesser General Public 15 License along with the GNU C Library; if not, see 16 <https://www.gnu.org/licenses/>. */ 17 18 #include <math.h> 19 #include <math_private.h> 20 #include <float.h> 21 #include <libm-alias-finite.h> 22 23 static const _Float128 log10_high = L(0x2.4d763776aaa2bp0); 24 static const _Float128 log10_low = L(0x5.ba95b58ae0b4c28a38a3fb3e7698p-60); 25 26 _Float128 __ieee754_exp10l(_Float128 arg)27__ieee754_exp10l (_Float128 arg) 28 { 29 ieee854_long_double_shape_type u; 30 _Float128 arg_high, arg_low; 31 _Float128 exp_high, exp_low; 32 33 if (!isfinite (arg)) 34 return __ieee754_expl (arg); 35 if (arg < LDBL_MIN_10_EXP - LDBL_DIG - 10) 36 return LDBL_MIN * LDBL_MIN; 37 else if (arg > LDBL_MAX_10_EXP + 1) 38 return LDBL_MAX * LDBL_MAX; 39 else if (fabsl (arg) < L(0x1p-116)) 40 return 1; 41 42 u.value = arg; 43 u.parts64.lsw &= 0xfe00000000000000LL; 44 arg_high = u.value; 45 arg_low = arg - arg_high; 46 exp_high = arg_high * log10_high; 47 exp_low = arg_high * log10_low + arg_low * M_LN10l; 48 return __ieee754_expl (exp_high) * __ieee754_expl (exp_low); 49 } 50 libm_alias_finite (__ieee754_exp10l, __exp10l) 51