glibc/sysdeps/ieee754/ldbl-96/s_getpayloadl.c
Joseph Myers 6c010c5dde Use C2x return value from getpayload of non-NaN (bug 26073).
In TS 18661-1, getpayload had an unspecified return value for a
non-NaN argument, while C2x requires the return value -1 in that case.

This patch implements the return value of -1.  I don't think this is
worth having a new symbol version that's an alias of the old one,
although occasionally we do that in such cases where the new function
semantics are a refinement of the old ones (to avoid programs relying
on the new semantics running on older glibc versions but not behaving
as intended).

Tested for x86_64 and x86; also ran math/ tests for aarch64 and
powerpc.
2020-07-06 16:18:02 +00:00

38 lines
1.3 KiB
C

/* Get NaN payload. ldbl-96 version.
Copyright (C) 2016-2020 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
<https://www.gnu.org/licenses/>. */
#include <math.h>
#include <math_private.h>
#include <libm-alias-ldouble.h>
#include <stdint.h>
long double
__getpayloadl (const long double *x)
{
uint16_t se __attribute__ ((unused));
uint32_t hx, lx;
GET_LDOUBLE_WORDS (se, hx, lx, *x);
if ((se & 0x7fff) != 0x7fff
|| ((hx & 0x7fffffff) | lx) == 0)
return -1;
hx &= 0x3fffffff;
uint64_t ix = ((uint64_t) hx << 32) | lx;
return (long double) ix;
}
libm_alias_ldouble (__getpayload, getpayload)