1 /* roundf(). RISC-V version.
2 Copyright (C) 2017-2022 Free Software Foundation, Inc.
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 #define NO_MATH_REDIRECT
20 #include <math.h>
21 #include <fenv_private.h>
22 #include <libm-alias-float.h>
23 #include <stdint.h>
24
25 float
__roundf(float x)26 __roundf (float x)
27 {
28 int flags = riscv_getflags ();
29 bool nan = isnan (x);
30 float mag = fabsf (x);
31
32 if (nan)
33 return x + x;
34
35 if (mag < (1 << __FLT_MANT_DIG__))
36 {
37 int32_t i;
38 float new_x;
39
40 asm volatile ("fcvt.w.s %0, %1, rmm" : "=r" (i) : "f" (x));
41 asm volatile ("fcvt.s.w %0, %1, rmm" : "=f" (new_x) : "r" (i));
42
43 /* round(-0) == -0, and in general we'll always have the same
44 sign as our input. */
45 x = copysignf (new_x, x);
46
47 riscv_setflags (flags);
48 }
49
50 return x;
51 }
52
53 libm_alias_float (__round, round)
54