1/* llrintl() - 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#if defined __s390x__ && defined HAVE_S390_MIN_Z196_ZARCH_ASM_SUPPORT
21/* We only support s390x as on s390 a long long int refers to a register pair
22 of two 4byte registers instead of a 8byte register which is produced by the
23 instruction.
24 Note: On s390 this instruction would only be used if build with -mzarch. */
25# include <math.h>
26# include <math_private.h>
27# include <libm-alias-ldouble.h>
28
29long long int
30__llrintl (_Float128 x)
31{
32 long long int y;
33 /* The z196 zarch "convert to fixed" (cgxbra) instruction is rounding
34 according to current rounding mode (M3-field: 0).
35 First convert x with suppressed inexact exception and check if the
36 resulting value is beyond the target limits (indicated by cc=3;
37 Note: a nan is also indicated by cc=3).
38 If the resulting value is within the target limits, redo
39 without suppressing the inexact exception. */
40 __asm__ ("cgxbra %0,0,%1,4 \n\t"
41 "jo 1f \n\t"
42 "cgxbra %0,0,%1,0 \n\t"
43 "1:"
44 : "=&d" (y) : "f" (x) : "cc");
45 return y;
46}
47libm_alias_ldouble (__llrint, llrint)
48
49#else
50# include <sysdeps/ieee754/ldbl-128/s_llrintl.c>
51#endif
52

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