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60 lines
1.7 KiB
C
60 lines
1.7 KiB
C
/* Construct a quiet NaN 'double' with a given payload.
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Copyright 2024-2026 Free Software Foundation, Inc.
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This file is free software: you can redistribute it and/or modify
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it under the terms of the GNU Lesser General Public License as
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published by the Free Software Foundation, either version 3 of the
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License, or (at your option) any later version.
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This file is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public License
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along with this program. If not, see <https://www.gnu.org/licenses/>. */
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/* Written by Bruno Haible. */
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#include <config.h>
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/* Specification. */
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#include <math.h>
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#include <float.h>
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#include <stdint.h>
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#include "signed-nan.h"
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int
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setpayload (double *result, double payload)
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{
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#if DBL_MANT_DIG == 53
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if (
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# if defined __hppa || (defined __mips__ && !MIPS_NAN2008_DOUBLE) || defined __sh__
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/* A zero payload is not allowed, because that would denote Infinity.
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Cf. snan.h. */
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payload > 0.0
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# else
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payload >= 0.0
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# endif
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&& payload < 2251799813685248.0 /* (double) (1ULL << (DBL_MANT_DIG - 2)) */
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&& payload == (double) (int64_t) payload)
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{
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union { uint64_t i; double f; } x;
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x.f = positive_NaNd ();
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x.i = (x.i & ~(((uint64_t) 1 << (DBL_MANT_DIG - 2)) - 1))
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| (int64_t) payload;
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*result = x.f;
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return 0;
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}
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else
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{
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*result = 0.0;
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return -1;
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}
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#else
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# error "Please port gnulib setpayload.c to your platform!"
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#endif
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}
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