| 1 | /* round(). RISC-V version. |
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| 2 | Copyright (C) 2017-2024 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 | #define NO_MATH_REDIRECT |
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| 20 | #include <math.h> |
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| 21 | #include <fenv_private.h> |
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| 22 | #include <libm-alias-double.h> |
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| 23 | #include <stdint.h> |
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| 24 | |
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| 25 | double |
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| 26 | __round (double x) |
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| 27 | { |
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| 28 | int flags = riscv_getflags (); |
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| 29 | bool nan = isnan (x); |
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| 30 | double mag = fabs (x: x); |
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| 31 | |
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| 32 | if (nan) |
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| 33 | return x + x; |
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| 34 | |
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| 35 | if (mag < (1ULL << __DBL_MANT_DIG__)) |
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| 36 | { |
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| 37 | int64_t i; |
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| 38 | double new_x; |
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| 39 | |
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| 40 | asm volatile ("fcvt.l.d %0, %1, rmm" : "=r" (i) : "f" (x)); |
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| 41 | asm volatile ("fcvt.d.l %0, %1, rmm" : "=f" (new_x) : "r" (i)); |
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| 42 | |
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| 43 | /* round(-0) == -0, and in general we'll always have the same |
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| 44 | sign as our input. */ |
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| 45 | x = copysign (x: new_x, y: x); |
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| 46 | |
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| 47 | riscv_setflags (flags); |
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| 48 | } |
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| 49 | |
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| 50 | return x; |
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| 51 | } |
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| 52 | |
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| 53 | libm_alias_double (__round, round) |
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| 54 | |
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