glibc/sysdeps/ieee754/ldbl-128/s_getpayloadl.c

58 lines
1.6 KiB
C

/* Get NaN payload. ldbl-128 version.
Copyright (C) 2016-2017 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 <math.h>
#include <math_private.h>
#include <stdint.h>
_Float128
getpayloadl (const _Float128 *x)
{
uint64_t hx, lx;
GET_LDOUBLE_WORDS64 (hx, lx, *x);
hx &= 0x7fffffffffffULL;
/* Construct the representation of the return value directly, since
128-bit integers may not be available. */
int lz;
if (hx == 0)
{
if (lx == 0)
return 0.0L;
else
lz = __builtin_clzll (lx) + 64;
}
else
lz = __builtin_clzll (hx);
int shift = lz - 15;
if (shift >= 64)
{
hx = lx << (shift - 64);
lx = 0;
}
else
{
/* 2 <= SHIFT <= 63. */
hx = (hx << shift) | (lx >> (64 - shift));
lx <<= shift;
}
hx = (hx & 0xffffffffffffULL) | ((0x3fffULL + 127 - lz) << 48);
_Float128 ret;
SET_LDOUBLE_WORDS64 (ret, hx, lx);
return ret;
}