mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-28 15:51:07 +00:00
86 lines
2.3 KiB
C
86 lines
2.3 KiB
C
/* Round to integer type. ldbl-96 version.
|
|
Copyright (C) 2016-2024 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 <errno.h>
|
|
#include <fenv.h>
|
|
#include <math.h>
|
|
#include <math_private.h>
|
|
#include <libm-alias-ldouble.h>
|
|
#include <stdbool.h>
|
|
#include <stdint.h>
|
|
|
|
#define BIAS 0x3fff
|
|
#define MANT_DIG 64
|
|
|
|
#if UNSIGNED
|
|
# define RET_TYPE uintmax_t
|
|
#else
|
|
# define RET_TYPE intmax_t
|
|
#endif
|
|
|
|
#include <fromfp.h>
|
|
|
|
RET_TYPE
|
|
FUNC (long double x, int round, unsigned int width)
|
|
{
|
|
if (width > INTMAX_WIDTH)
|
|
width = INTMAX_WIDTH;
|
|
uint16_t se;
|
|
uint32_t hx, lx;
|
|
GET_LDOUBLE_WORDS (se, hx, lx, x);
|
|
bool negative = (se & 0x8000) != 0;
|
|
if (width == 0)
|
|
return fromfp_domain_error (negative, width);
|
|
if ((hx | lx) == 0)
|
|
return 0;
|
|
int exponent = se & 0x7fff;
|
|
exponent -= BIAS;
|
|
int max_exponent = fromfp_max_exponent (negative, width);
|
|
if (exponent > max_exponent)
|
|
return fromfp_domain_error (negative, width);
|
|
|
|
uint64_t ix = (((uint64_t) hx) << 32) | lx;
|
|
uintmax_t uret;
|
|
bool half_bit, more_bits;
|
|
if (exponent >= MANT_DIG - 1)
|
|
{
|
|
uret = ix;
|
|
/* Exponent 63; no shifting required. */
|
|
half_bit = false;
|
|
more_bits = false;
|
|
}
|
|
else if (exponent >= -1)
|
|
{
|
|
uint64_t h = 1ULL << (MANT_DIG - 2 - exponent);
|
|
half_bit = (ix & h) != 0;
|
|
more_bits = (ix & (h - 1)) != 0;
|
|
if (exponent == -1)
|
|
uret = 0;
|
|
else
|
|
uret = ix >> (MANT_DIG - 1 - exponent);
|
|
}
|
|
else
|
|
{
|
|
uret = 0;
|
|
half_bit = false;
|
|
more_bits = true;
|
|
}
|
|
return fromfp_round_and_return (negative, uret, half_bit, more_bits, round,
|
|
exponent, max_exponent, width);
|
|
}
|