1/* Copyright (C) 1996-2022 Free Software Foundation, Inc.
2
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19#include <math.h>
20#include <get-rounding-mode.h>
21#include <stdint.h>
22#include <math-barriers.h>
23#include <libm-alias-double.h>
24
25# define IREG_SIZE 64
26
27# ifdef __ILP32__
28# define OREG_SIZE 32
29# else
30# define OREG_SIZE 64
31# endif
32
33# define IREGS "d"
34
35#if OREG_SIZE == 32
36# define OREGS "w"
37#else
38# define OREGS "x"
39#endif
40
41
42long int
43__lrint (double x)
44{
45
46#if IREG_SIZE == 64 && OREG_SIZE == 32
47 long int result;
48
49 if (__builtin_fabs (x) > INT32_MAX)
50 {
51 /* Converting large values to a 32 bit int may cause the frintx/fcvtza
52 sequence to set both FE_INVALID and FE_INEXACT. To avoid this
53 check the rounding mode and do a single instruction with the
54 appropriate rounding mode. */
55
56 switch (get_rounding_mode ())
57 {
58 case FE_TONEAREST:
59 asm volatile ("fcvtns" "\t%" OREGS "0, %" IREGS "1"
60 : "=r" (result) : "w" (x));
61 break;
62 case FE_UPWARD:
63 asm volatile ("fcvtps" "\t%" OREGS "0, %" IREGS "1"
64 : "=r" (result) : "w" (x));
65 break;
66 case FE_DOWNWARD:
67 asm volatile ("fcvtms" "\t%" OREGS "0, %" IREGS "1"
68 : "=r" (result) : "w" (x));
69 break;
70 case FE_TOWARDZERO:
71 default:
72 asm volatile ("fcvtzs" "\t%" OREGS "0, %" IREGS "1"
73 : "=r" (result) : "w" (x));
74 }
75 return result;
76 }
77#endif
78
79 double r = __builtin_rint (x);
80
81 /* Prevent gcc from calling lrint directly when compiled with
82 -fno-math-errno by inserting a barrier. */
83
84 math_opt_barrier (r);
85 return r;
86}
87
88libm_alias_double (__lrint, lrint)
89

source code of glibc/sysdeps/aarch64/fpu/s_lrint.c