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aaee3cd8 | 1 | /* Narrow floating-point values to their semantic type. |
04277e02 | 2 | Copyright (C) 2015-2019 Free Software Foundation, Inc. |
aaee3cd8 JM |
3 | This file is part of the GNU C Library. |
4 | ||
5 | The GNU C Library is free software; you can redistribute it and/or | |
6 | modify it under the terms of the GNU Lesser General Public | |
7 | License as published by the Free Software Foundation; either | |
8 | version 2.1 of the License, or (at your option) any later version. | |
9 | ||
10 | The GNU C Library is distributed in the hope that it will be useful, | |
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
13 | Lesser General Public License for more details. | |
14 | ||
15 | You should have received a copy of the GNU Lesser General Public | |
16 | License along with the GNU C Library; if not, see | |
17 | <http://www.gnu.org/licenses/>. */ | |
18 | ||
19 | #ifndef _MATH_NARROW_EVAL_H | |
20 | #define _MATH_NARROW_EVAL_H 1 | |
21 | ||
22 | #include <float.h> | |
23 | ||
24 | /* math_narrow_eval reduces its floating-point argument to the range | |
25 | and precision of its semantic type. (The original evaluation may | |
26 | still occur with excess range and precision, so the result may be | |
27 | affected by double rounding.) */ | |
28 | #if FLT_EVAL_METHOD == 0 | |
29 | # define math_narrow_eval(x) (x) | |
30 | #else | |
31 | # if FLT_EVAL_METHOD == 1 | |
32 | # define excess_precision(type) __builtin_types_compatible_p (type, float) | |
33 | # else | |
34 | # define excess_precision(type) (__builtin_types_compatible_p (type, float) \ | |
35 | || __builtin_types_compatible_p (type, \ | |
36 | double)) | |
37 | # endif | |
38 | # define math_narrow_eval(x) \ | |
39 | ({ \ | |
40 | __typeof (x) math_narrow_eval_tmp = (x); \ | |
41 | if (excess_precision (__typeof (math_narrow_eval_tmp))) \ | |
42 | __asm__ ("" : "+m" (math_narrow_eval_tmp)); \ | |
43 | math_narrow_eval_tmp; \ | |
44 | }) | |
45 | #endif | |
46 | ||
47 | #endif /* math-narrow-eval.h */ |