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git.ipfire.org Git - thirdparty/glibc.git/blob - sysdeps/ieee754/ldbl-96/s_iscanonicall.c
1 /* Test whether long double value is canonical. ldbl-96 version.
2 Copyright (C) 2016 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <http://www.gnu.org/licenses/>. */
21 #include <math_private.h>
26 __iscanonicall (long double x
)
28 uint32_t se
, i0
, i1
__attribute__ ((unused
));
30 GET_LDOUBLE_WORDS (se
, i0
, i1
, x
);
31 int32_t ix
= se
& 0x7fff;
32 bool mant_high
= (i0
& 0x80000000) != 0;
34 if (LDBL_MIN_EXP
== -16381)
35 /* Intel variant: the high mantissa bit should have a value
36 determined by the exponent. */
37 return ix
> 0 ? mant_high
: !mant_high
;
39 /* M68K variant: both values of the high bit are valid for the
40 greatest and smallest exponents, while other exponents require
41 the high bit to be set. */
42 return ix
== 0 || ix
== 0x7fff || mant_high
;
44 libm_hidden_def (__iscanonicall
)