| 1 | /* Check for underflow and force underflow exceptions. |
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| 2 | Copyright (C) 2015-2022 Free Software Foundation, Inc. |
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| 3 | This file is part of the GNU C Library. |
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| 4 | |
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| 5 | The GNU C Library is free software; you can redistribute it and/or |
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| 6 | modify it under the terms of the GNU Lesser General Public |
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| 7 | License as published by the Free Software Foundation; either |
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| 8 | version 2.1 of the License, or (at your option) any later version. |
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| 9 | |
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| 10 | The GNU C Library is distributed in the hope that it will be useful, |
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| 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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| 13 | Lesser General Public License for more details. |
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| 14 | |
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| 15 | You should have received a copy of the GNU Lesser General Public |
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| 16 | License along with the GNU C Library; if not, see |
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| 17 | <https://www.gnu.org/licenses/>. */ |
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| 18 | |
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| 19 | #ifndef _MATH_UNDERFLOW_H |
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| 20 | #define _MATH_UNDERFLOW_H 1 |
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| 21 | |
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| 22 | #include <float.h> |
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| 23 | #include <math.h> |
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| 24 | |
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| 25 | #include <math-barriers.h> |
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| 26 | |
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| 27 | #define fabs_tg(x) __MATH_TG ((x), (__typeof (x)) __builtin_fabs, (x)) |
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| 28 | |
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| 29 | /* These must be function-like macros because some __MATH_TG |
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| 30 | implementations macro-expand the function-name argument before |
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| 31 | concatenating a suffix to it. */ |
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| 32 | #define min_of_type_f() FLT_MIN |
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| 33 | #define min_of_type_() DBL_MIN |
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| 34 | #define min_of_type_l() LDBL_MIN |
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| 35 | #define min_of_type_f128() FLT128_MIN |
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| 36 | |
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| 37 | #define min_of_type(x) __MATH_TG ((x), (__typeof (x)) min_of_type_, ()) |
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| 38 | |
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| 39 | /* If X (which is not a NaN) is subnormal, force an underflow |
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| 40 | exception. */ |
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| 41 | #define math_check_force_underflow(x) \ |
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| 42 | do \ |
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| 43 | { \ |
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| 44 | __typeof (x) force_underflow_tmp = (x); \ |
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| 45 | if (fabs_tg (force_underflow_tmp) \ |
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| 46 | < min_of_type (force_underflow_tmp)) \ |
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| 47 | { \ |
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| 48 | __typeof (force_underflow_tmp) force_underflow_tmp2 \ |
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| 49 | = force_underflow_tmp * force_underflow_tmp; \ |
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| 50 | math_force_eval (force_underflow_tmp2); \ |
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| 51 | } \ |
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| 52 | } \ |
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| 53 | while (0) |
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| 54 | /* Likewise, but X is also known to be nonnegative. */ |
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| 55 | #define math_check_force_underflow_nonneg(x) \ |
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| 56 | do \ |
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| 57 | { \ |
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| 58 | __typeof (x) force_underflow_tmp = (x); \ |
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| 59 | if (force_underflow_tmp \ |
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| 60 | < min_of_type (force_underflow_tmp)) \ |
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| 61 | { \ |
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| 62 | __typeof (force_underflow_tmp) force_underflow_tmp2 \ |
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| 63 | = force_underflow_tmp * force_underflow_tmp; \ |
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| 64 | math_force_eval (force_underflow_tmp2); \ |
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| 65 | } \ |
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| 66 | } \ |
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| 67 | while (0) |
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| 68 | /* Likewise, for both real and imaginary parts of a complex |
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| 69 | result. */ |
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| 70 | #define math_check_force_underflow_complex(x) \ |
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| 71 | do \ |
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| 72 | { \ |
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| 73 | __typeof (x) force_underflow_complex_tmp = (x); \ |
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| 74 | math_check_force_underflow (__real__ force_underflow_complex_tmp); \ |
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| 75 | math_check_force_underflow (__imag__ force_underflow_complex_tmp); \ |
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| 76 | } \ |
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| 77 | while (0) |
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| 78 | |
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| 79 | #endif /* math-underflow.h */ |
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| 80 | |
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