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 |
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 (x: 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 | |