1 /* lrintf() - S390 version.
2 Copyright (C) 2019-2022 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
33 long int
__lrintf(float x)34 __lrintf (float x)
35 {
36 long int y;
37 /* The z196 zarch "convert to fixed" (cgebra) instruction is rounding
38 according to current rounding mode (M3-field: 0).
39 First convert x with suppressed inexact exception and check if the
40 resulting value is beyond the target limits (indicated by cc=3;
41 Note: a nan is also indicated by cc=3).
42 If the resulting value is within the target limits, redo
43 without suppressing the inexact exception. */
44 __asm__ (INSN " %0,0,%1,4 \n\t"
45 "jo 1f \n\t"
46 INSN " %0,0,%1,0 \n\t"
47 "1:"
48 : "=&d" (y) : "f" (x) : "cc");
49 return y;
50 }
51 libm_alias_float (__lrint, lrint)
52
53 #else
54 # include <sysdeps/ieee754/flt-32/s_lrintf.c>
55 #endif
56