Chris Metcalf 1dca195e1c lround: provide cast for wordsize-64 version if needed
Platforms with 64-bit registers where 32-bit values need to have the
high 32 bits set in a particular way need to have an explicit cast
when using the 64-bit sysdeps/ieee754/dbl-64/wordsize-64 version
of llround() as lround().  This includes tilegx32, and likely MIPS.
x32 does not need this, and AArch64 ILP32 will not either.  Require
it to be specified in sysdep.h to be explicit.
2015-01-05 11:59:32 -05:00

96 lines
2.4 KiB
C

/* Round double value to long long int.
Copyright (C) 1997-2015 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
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/>. */
#define lround __hidden_lround
#define __lround __hidden___lround
#include <math.h>
#include <sysdep.h>
#include <math_private.h>
long long int
__llround (double x)
{
int32_t j0;
int64_t i0;
long long int result;
int sign;
EXTRACT_WORDS64 (i0, x);
j0 = ((i0 >> 52) & 0x7ff) - 0x3ff;
sign = i0 < 0 ? -1 : 1;
i0 &= UINT64_C(0xfffffffffffff);
i0 |= UINT64_C(0x10000000000000);
if (j0 < (int32_t) (8 * sizeof (long long int)) - 1)
{
if (j0 < 0)
return j0 < -1 ? 0 : sign;
else if (j0 >= 52)
result = i0 << (j0 - 52);
else
{
i0 += UINT64_C(0x8000000000000) >> j0;
result = i0 >> (52 - j0);
}
}
else
{
/* The number is too large. It is left implementation defined
what happens. */
return (long long int) x;
}
return sign * result;
}
weak_alias (__llround, llround)
#ifdef NO_LONG_DOUBLE
strong_alias (__llround, __llroundl)
weak_alias (__llround, llroundl)
#endif
/* long has the same width as long long on LP64 machines, so use an alias.
If building for ILP32 on a machine with 64-bit registers, however,
use a cast if necessary. */
#undef lround
#undef __lround
#if !defined (_LP64) && REGISTER_CAST_INT32_TO_INT64
long int
__lround (double x)
{
return __llround (x);
}
weak_alias (__lround, lround)
# ifdef NO_LONG_DOUBLE
strong_alias (__lround, __lroundl)
weak_alias (__lround, lroundl)
# endif
#else
strong_alias (__llround, __lround)
weak_alias (__llround, lround)
# ifdef NO_LONG_DOUBLE
strong_alias (__llround, __lroundl)
weak_alias (__llround, lroundl)
# endif
#endif