Joseph Myers b75bc69cdf Don't use dbl-64/wordsize-64 lround based on llround for ILP32 (bug 19079).
The implementation of lround in dbl-64/wordsize-64 as an alias or
wrapper for llround is always incorrect when long is not 64-bit,
because it misses required exceptions in overflow cases, as shown by
my recently added tests.  This patch removes that alias / wrapper in
the non-LP64 case, together with the REGISTER_CAST_INT32_TO_INT64
macro, restoring the previous version of lround for dbl-64/wordsize-64
(newly conditioned on !_LP64).

Tested for x86_64, and for mips64 with use of dbl-64/wordsize-64
enabled.

	[BZ #19079]
	* sysdeps/ieee754/dbl-64/wordsize-64/s_lround.c: Restore previous
	file, conditioned on [!_LP64].
	* sysdeps/ieee754/dbl-64/wordsize-64/s_llround.c
	[!_LP64] (__lround): Do not define as function or alias.
	[!_LP64] (lround): Likewise.
	[!_LP64] (__lroundl): Likewise.
	[!_LP64] (lroundl): Likewise.
	* sysdeps/tile/sysdep.h (REGISTER_CAST_INT32_TO_INT64): Remove
	macro.
	* sysdeps/x86_64/x32/sysdep.h (REGISTER_CAST_INT32_TO_INT64):
	Likewise.
2015-10-07 00:40:12 +00:00

83 lines
2.1 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. */
#undef lround
#undef __lround
#ifdef _LP64
strong_alias (__llround, __lround)
weak_alias (__llround, lround)
# ifdef NO_LONG_DOUBLE
strong_alias (__llround, __lroundl)
weak_alias (__llround, lroundl)
# endif
#endif