| 1 | /* lround function. POWER6x, PowerPC32 version. |
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| 2 | Copyright (C) 2006-2024 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 | #include <sysdep.h> |
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| 20 | #include <math_ldbl_opt.h> |
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| 21 | #include <libm-alias-float.h> |
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| 22 | #include <libm-alias-double.h> |
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| 23 | |
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| 24 | /* long [r3] lround (float x [fp1]) |
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| 25 | IEEE 1003.1 lround function. IEEE specifies "round to the nearest |
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| 26 | integer value, rounding halfway cases away from zero, regardless of |
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| 27 | the current rounding mode." However PowerPC Architecture defines |
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| 28 | "round to Nearest" as "Choose the best approximation. In case of a |
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| 29 | tie, choose the one that is even (least significant bit o).". |
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| 30 | So we pre-round using the V2.02 Floating Round to Integer Nearest |
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| 31 | instruction before we use the Floating Convert to Integer Word with |
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| 32 | round to zero instruction. */ |
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| 33 | |
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| 34 | .machine "power6" |
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| 35 | ENTRY (__lround) |
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| 36 | frin fp2,fp1 /* Pre-round +-0.5. */ |
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| 37 | fctiwz fp3,fp2 /* Convert To Integer Word lround toward 0. */ |
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| 38 | mftgpr r3,fp3 /* Transfer fpr3 to r3. */ |
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| 39 | blr |
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| 40 | END (__lround) |
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| 41 | |
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| 42 | libm_alias_double (__lround, lround) |
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| 43 | |
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| 44 | strong_alias (__lround, __lroundf) |
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| 45 | libm_alias_float (__lround, lround) |
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| 46 | |
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