1 | /* llrint() - 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 <libm-alias-double.h> |
27 | |
28 | long long int |
29 | __llrint (double x) |
30 | { |
31 | long long int y; |
32 | /* The z196 zarch "convert to fixed" (cgdbra) instruction is rounding |
33 | according to current rounding mode (M3-field: 0). |
34 | First convert x with suppressed inexact exception and check if the |
35 | resulting value is beyond the target limits (indicated by cc=3; |
36 | Note: a nan is also indicated by cc=3). |
37 | If the resulting value is within the target limits, redo |
38 | without suppressing the inexact exception. */ |
39 | __asm__ ("cgdbra %0,0,%1,4 \n\t" |
40 | "jo 1f \n\t" |
41 | "cgdbra %0,0,%1,0 \n\t" |
42 | "1:" |
43 | : "=&d" (y) : "f" (x) : "cc" ); |
44 | return y; |
45 | } |
46 | libm_alias_double (__llrint, llrint) |
47 | |
48 | #else |
49 | # include <sysdeps/ieee754/dbl-64/s_llrint.c> |
50 | #endif |
51 | |