diff options
Diffstat (limited to 'sysdeps/ieee754/ldbl-96/s_iscanonicall.c')
-rw-r--r-- | sysdeps/ieee754/ldbl-96/s_iscanonicall.c | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/sysdeps/ieee754/ldbl-96/s_iscanonicall.c b/sysdeps/ieee754/ldbl-96/s_iscanonicall.c new file mode 100644 index 0000000..f820030 --- /dev/null +++ b/sysdeps/ieee754/ldbl-96/s_iscanonicall.c @@ -0,0 +1,43 @@ +/* Test whether long double value is canonical. ldbl-96 version. + Copyright (C) 2016 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +#include <float.h> +#include <math.h> +#include <math_private.h> +#include <stdbool.h> +#include <stdint.h> + +int +__iscanonicall (long double x) +{ + uint32_t se, i0, i1 __attribute__ ((unused)); + + GET_LDOUBLE_WORDS (se, i0, i1, x); + int32_t ix = se & 0x7fff; + bool mant_high = (i0 & 0x80000000) != 0; + + if (LDBL_MIN_EXP == -16381) + /* Intel variant: the high mantissa bit should have a value + determined by the exponent. */ + return ix > 0 ? mant_high : !mant_high; + else + /* M68K variant: both values of the high bit are valid for the + greatest and smallest exponents, while other exponents require + the high bit to be set. */ + return ix == 0 || ix == 0x7fff || mant_high; +} |