| 1 | /* Multiply by integral power of radix. |
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| 2 | |
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| 3 | Copyright (C) 2011-2022 Free Software Foundation, Inc. |
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| 4 | |
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| 5 | This file is part of the GNU C Library. |
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| 6 | |
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| 7 | The GNU C Library is free software; you can redistribute it and/or |
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| 8 | modify it under the terms of the GNU Lesser General Public |
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| 9 | License as published by the Free Software Foundation; either |
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| 10 | version 2.1 of the License, or (at your option) any later version. |
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| 11 | |
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| 12 | The GNU C Library is distributed in the hope that it will be useful, |
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| 13 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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| 15 | Lesser General Public License for more details. |
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| 16 | |
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| 17 | You should have received a copy of the GNU Lesser General Public |
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| 18 | License along with the GNU C Library; if not, see |
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| 19 | <https://www.gnu.org/licenses/>. */ |
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| 20 | |
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| 21 | #include <math.h> |
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| 22 | #include <math_private.h> |
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| 23 | #include <libm-alias-finite.h> |
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| 24 | |
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| 25 | static FLOAT |
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| 26 | __attribute__ ((noinline)) |
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| 27 | invalid_fn (FLOAT x, FLOAT fn) |
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| 28 | { |
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| 29 | if (M_SUF (rint) (fn) != fn) |
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| 30 | return (fn - fn) / (fn - fn); |
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| 31 | else if (fn > M_LIT (65000.0)) |
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| 32 | return M_SUF (__scalbn) (x, 65000); |
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| 33 | else |
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| 34 | return M_SUF (__scalbn) (x,-65000); |
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| 35 | } |
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| 36 | |
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| 37 | |
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| 38 | FLOAT |
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| 39 | M_DECL_FUNC (__ieee754_scalb) (FLOAT x, FLOAT fn) |
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| 40 | { |
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| 41 | if (__glibc_unlikely (isnan (x))) |
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| 42 | return x * fn; |
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| 43 | if (__glibc_unlikely (!isfinite (fn))) |
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| 44 | { |
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| 45 | if (isnan (fn) || fn > M_LIT (0.0)) |
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| 46 | return x * fn; |
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| 47 | if (x == M_LIT (0.0)) |
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| 48 | return x; |
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| 49 | return x / -fn; |
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| 50 | } |
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| 51 | if (__glibc_unlikely (M_FABS (fn) >= M_LIT (0x1p31) |
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| 52 | || (FLOAT) (int) fn != fn)) |
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| 53 | return invalid_fn (x, fn); |
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| 54 | |
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| 55 | return M_SCALBN (x, (int) fn); |
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| 56 | } |
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| 57 | declare_mgen_finite_alias (__ieee754_scalb, __scalb) |
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| 58 | |
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