1 /* Copyright (C) 2012-2022 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 long double log10_high = 0x2.4d763776aaap+0L; 24 static const long double log10_low = 0x2.b05ba95b58ae0b4c28a38a3fb4p-48L; 25 26 long double __ieee754_exp10l(long double arg)27__ieee754_exp10l (long double arg) 28 { 29 union ibm_extended_long_double u; 30 long double arg_high, arg_low; 31 long double 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) < 0x1p-109L) 40 return 1.0L; 41 42 u.ld = arg; 43 arg_high = u.d[0].d; 44 arg_low = u.d[1].d; 45 exp_high = arg_high * log10_high; 46 exp_low = arg_high * log10_low + arg_low * M_LN10l; 47 return __ieee754_expl (exp_high) * __ieee754_expl (exp_low); 48 } 49 libm_alias_finite (__ieee754_exp10l, __exp10l) 50