glibc/sysdeps/s390/fpu/s_lround.c

48 lines
1.6 KiB
C

/* lround() - S390 version.
Copyright (C) 2019-2020 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/>. */
#ifdef HAVE_S390_MIN_Z196_ZARCH_ASM_SUPPORT
# include <math.h>
# include <libm-alias-double.h>
/* The sizeof (long int) differs between s390x (8byte) and s390 (4byte).
Thus we need different instructions as the target size is encoded there.
Note: On s390 this instruction is only used if build with -mzarch. */
# ifdef __s390x__
# define INSN "cgdbra"
# else
# define INSN "cfdbra"
# endif
long int
__lround (double x)
{
long int y;
/* The z196 zarch "convert to fixed" (cgdbra) instruction is rounding
x to the nearest integer with "ties away from 0" rounding mode
(M3-field: 1) where inexact exceptions are suppressed (M4-field: 4). */
__asm__ (INSN " %0,1,%1,4" : "=d" (y) : "f" (x) : "cc");
return y;
}
libm_alias_double (__lround, lround)
#else
# include <sysdeps/ieee754/dbl-64/s_lround.c>
#endif