1/* lroundf() - S390 version.
2 Copyright (C) 2019-2024 Free Software Foundation, Inc.
3
4 This file is part of the GNU C Library.
5
6 The GNU C Library is free software; you can redistribute it and/or
7 modify it under the terms of the GNU Lesser General Public License as
8 published by the Free Software Foundation; either version 2.1 of the
9 License, or (at your option) any later version.
10
11 The GNU C Library is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Lesser General Public License for more details.
15
16 You should have received a copy of the GNU Lesser General Public
17 License along with the GNU C Library; if not, see
18 <https://www.gnu.org/licenses/>. */
19
20#ifdef HAVE_S390_MIN_Z196_ZARCH_ASM_SUPPORT
21# include <math.h>
22# include <libm-alias-float.h>
23
24/* The sizeof (long int) differs between s390x (8byte) and s390 (4byte).
25 Thus we need different instructions as the target size is encoded there.
26 Note: On s390 this instruction is only used if build with -mzarch. */
27# ifdef __s390x__
28# define INSN "cgebra"
29# else
30# define INSN "cfebra"
31# endif
32
33long int
34__lroundf (float x)
35{
36 long int y;
37 /* The z196 zarch "convert to fixed" (cgebra) instruction is rounding
38 x to the nearest integer with "ties away from 0" rounding mode
39 (M3-field: 1) where inexact exceptions are suppressed (M4-field: 4). */
40 __asm__ (INSN " %0,1,%1,4" : "=d" (y) : "f" (x) : "cc");
41 return y;
42}
43libm_alias_float (__lround, lround)
44
45#else
46# include <sysdeps/ieee754/flt-32/s_lroundf.c>
47#endif
48

source code of glibc/sysdeps/s390/fpu/s_lroundf.c