45 lines
1.6 KiB
C
45 lines
1.6 KiB
C
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/* Test whether long double value is canonical. ldbl-96 version.
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Copyright (C) 2016-2022 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library 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 GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<https://www.gnu.org/licenses/>. */
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#include <float.h>
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#include <math.h>
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#include <math_private.h>
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#include <stdbool.h>
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#include <stdint.h>
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int
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__iscanonicall (long double x)
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{
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uint32_t se, i0, i1 __attribute__ ((unused));
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GET_LDOUBLE_WORDS (se, i0, i1, x);
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int32_t ix = se & 0x7fff;
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bool mant_high = (i0 & 0x80000000) != 0;
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if (LDBL_MIN_EXP == -16381)
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/* Intel variant: the high mantissa bit should have a value
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determined by the exponent. */
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return ix > 0 ? mant_high : !mant_high;
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else
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/* M68K variant: both values of the high bit are valid for the
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greatest and smallest exponents, while other exponents require
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the high bit to be set. */
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return ix == 0 || ix == 0x7fff || mant_high;
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}
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libm_hidden_def (__iscanonicall)
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