1 | /* lrint() - 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-double.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 "cgdbra" |
29 | # else |
30 | # define INSN "cfdbra" |
31 | # endif |
32 | |
33 | long int |
34 | __lrint (double x) |
35 | { |
36 | long int y; |
37 | /* The z196 zarch "convert to fixed" (cgdbra) 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_double (__lrint, lrint) |
52 | |
53 | #else |
54 | # include <sysdeps/ieee754/dbl-64/s_lrint.c> |
55 | #endif |
56 | |