glibc/sysdeps/ieee754/dbl-64/s_llrint.c
Joseph Myers 54142c44e9 Use math_narrow_eval more consistently.
Where glibc code needs to avoid excess range and precision in
floating-point arithmetic, code variously uses either asms or volatile
to force the results of that arithmetic to memory; mostly this is
conditional on FLT_EVAL_METHOD, but in the case of lrint / llrint
functions some use of volatile is unconditional (and is present
unnecessarily in versions for long double).  This patch make such code
use the recently-added math_narrow_eval macro consistently, removing
the unnecessary uses of volatile in long double lrint / llrint
implementations completely.

Tested for x86_64, x86, mips64 and powerpc.

	* math/s_nexttowardf.c (__nexttowardf): Use math_narrow_eval.
	* stdlib/strtod_l.c: Include <math_private.h>.
	(overflow_value): Use math_narrow_eval.
	(underflow_value): Likewise.
	* sysdeps/i386/fpu/s_nexttoward.c (__nexttoward): Likewise.
	* sysdeps/i386/fpu/s_nexttowardf.c (__nexttowardf): Likewise.
	* sysdeps/ieee754/dbl-64/e_gamma_r.c (gamma_positive): Likewise.
	(__ieee754_gamma_r): Likewise.
	* sysdeps/ieee754/dbl-64/gamma_productf.c (__gamma_productf):
	Likewise.
	* sysdeps/ieee754/dbl-64/k_rem_pio2.c (__kernel_rem_pio2):
	Likewise.
	* sysdeps/ieee754/dbl-64/lgamma_neg.c (__lgamma_neg): Likewise.
	* sysdeps/ieee754/dbl-64/s_erf.c (__erfc): Likewise.
	* sysdeps/ieee754/dbl-64/s_llrint.c (__llrint): Likewise.
	* sysdeps/ieee754/dbl-64/s_lrint.c (__lrint): Likewise.
	* sysdeps/ieee754/flt-32/e_gammaf_r.c (gammaf_positive): Likewise.
	(__ieee754_gammaf_r): Likewise.
	* sysdeps/ieee754/flt-32/k_rem_pio2f.c (__kernel_rem_pio2f):
	Likewise.
	* sysdeps/ieee754/flt-32/lgamma_negf.c (__lgamma_negf): Likewise.
	* sysdeps/ieee754/flt-32/s_erff.c (__erfcf): Likewise.
	* sysdeps/ieee754/flt-32/s_llrintf.c (__llrintf): Likewise.
	* sysdeps/ieee754/flt-32/s_lrintf.c (__lrintf): Likewise.
	* sysdeps/ieee754/ldbl-128/s_llrintl.c (__llrintl): Do not use
	volatile.
	* sysdeps/ieee754/ldbl-128/s_lrintl.c (__lrintl): Likewise.
	* sysdeps/ieee754/ldbl-128/s_nexttoward.c (__nexttoward): Use
	math_narrow_eval.
	* sysdeps/ieee754/ldbl-128ibm/s_nexttoward.c (__nexttoward):
	Likewise.
	* sysdeps/ieee754/ldbl-128ibm/s_nexttowardf.c (__nexttowardf):
	Likewise.
	* sysdeps/ieee754/ldbl-96/gamma_product.c (__gamma_product):
	Likewise.
	* sysdeps/ieee754/ldbl-96/s_llrintl.c (__llrintl): Do not use
	volatile.
	* sysdeps/ieee754/ldbl-96/s_lrintl.c (__lrintl): Likewise.
	* sysdeps/ieee754/ldbl-96/s_nexttoward.c (__nexttoward): Use
	math_narrow_eval.
	* sysdeps/ieee754/ldbl-96/s_nexttowardf.c (__nexttowardf):
	Likewise.
	* sysdeps/ieee754/ldbl-opt/s_nexttowardfd.c (__nldbl_nexttowardf):
	Likewise.
2015-09-23 18:14:57 +00:00

93 lines
2.4 KiB
C

/* Round argument to nearest integral value according to current rounding
direction.
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/>. */
#include <math.h>
#include <math_private.h>
static const double two52[2] =
{
4.50359962737049600000e+15, /* 0x43300000, 0x00000000 */
-4.50359962737049600000e+15, /* 0xC3300000, 0x00000000 */
};
long long int
__llrint (double x)
{
int32_t j0;
u_int32_t i1, i0;
long long int result;
double w;
double t;
int sx;
EXTRACT_WORDS (i0, i1, x);
j0 = ((i0 >> 20) & 0x7ff) - 0x3ff;
sx = i0 >> 31;
i0 &= 0xfffff;
i0 |= 0x100000;
if (j0 < 20)
{
w = math_narrow_eval (two52[sx] + x);
t = w - two52[sx];
EXTRACT_WORDS (i0, i1, t);
j0 = ((i0 >> 20) & 0x7ff) - 0x3ff;
i0 &= 0xfffff;
i0 |= 0x100000;
result = (j0 < 0 ? 0 : i0 >> (20 - j0));
}
else if (j0 < (int32_t) (8 * sizeof (long long int)) - 1)
{
if (j0 >= 52)
result = (((long long int) i0 << 32) | i1) << (j0 - 52);
else
{
w = math_narrow_eval (two52[sx] + x);
t = w - two52[sx];
EXTRACT_WORDS (i0, i1, t);
j0 = ((i0 >> 20) & 0x7ff) - 0x3ff;
i0 &= 0xfffff;
i0 |= 0x100000;
if (j0 == 20)
result = (long long int) i0;
else
result = ((long long int) i0 << (j0 - 20)) | (i1 >> (52 - j0));
}
}
else
{
/* The number is too large. It is left implementation defined
what happens. */
return (long long int) x;
}
return sx ? -result : result;
}
weak_alias (__llrint, llrint)
#ifdef NO_LONG_DOUBLE
strong_alias (__llrint, __llrintl)
weak_alias (__llrint, llrintl)
#endif