| 1 | /* Copyright (C) 2003-2024 Free Software Foundation, Inc. |
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| 2 | This file is part of the GNU C Library. |
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| 3 | |
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| 4 | The GNU C Library is free software; you can redistribute it and/or |
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| 5 | modify it under the terms of the GNU Lesser General Public |
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| 6 | License as published by the Free Software Foundation; either |
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| 7 | version 2.1 of the License, or (at your option) any later version. |
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| 8 | |
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| 9 | The GNU C Library is distributed in the hope that it will be useful, |
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| 10 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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| 12 | Lesser General Public License for more details. |
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| 13 | |
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| 14 | You should have received a copy of the GNU Lesser General Public |
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| 15 | License along with the GNU C Library. If not, see |
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| 16 | <https://www.gnu.org/licenses/>. */ |
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| 17 | |
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| 18 | #include <math.h> |
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| 19 | |
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| 20 | long double |
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| 21 | __frexpl (long double value, int *expptr) |
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| 22 | { |
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| 23 | long double mantissa, exponent; |
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| 24 | int iexponent; |
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| 25 | unsigned long fpsr; |
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| 26 | |
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| 27 | __asm ("ftst%.x %1\n" |
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| 28 | "fmove%.l %/fpsr, %0" |
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| 29 | : "=dm" (fpsr) : "f" (value)); |
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| 30 | if (fpsr & (7 << 24)) |
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| 31 | { |
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| 32 | /* Not finite or zero. */ |
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| 33 | *expptr = 0; |
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| 34 | return value; |
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| 35 | } |
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| 36 | __asm ("fgetexp%.x %1, %0" : "=f" (exponent) : "f" (value)); |
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| 37 | iexponent = (int) exponent + 1; |
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| 38 | *expptr = iexponent; |
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| 39 | /* Unnormalized numbers must be handled specially, otherwise fscale |
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| 40 | results in overflow. */ |
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| 41 | if (iexponent <= -16384) |
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| 42 | { |
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| 43 | value *= 0x1p16383L; |
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| 44 | iexponent += 16383; |
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| 45 | } |
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| 46 | else if (iexponent >= 16384) |
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| 47 | { |
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| 48 | value *= 0x1p-16383L; |
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| 49 | iexponent -= 16383; |
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| 50 | } |
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| 51 | |
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| 52 | __asm ("fscale%.l %2, %0" |
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| 53 | : "=f" (mantissa) |
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| 54 | : "0" (value), "dmi" (-iexponent)); |
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| 55 | return mantissa; |
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| 56 | } |
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| 57 | |
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| 58 | weak_alias (__frexpl, frexpl) |
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| 59 | |
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