1/*	$NetBSD: fpsetround.c,v 1.9 2024/03/20 06:15:39 rillig Exp $	*/
2
3/*
4 * Written by J.T. Conklin, Apr 10, 1995
5 * Public domain.
6 */
7
8#include <sys/cdefs.h>
9#if defined(LIBC_SCCS) && !defined(lint)
10__RCSID("$NetBSD: fpsetround.c,v 1.9 2024/03/20 06:15:39 rillig Exp $");
11#endif /* LIBC_SCCS and not lint */
12
13#include "namespace.h"
14
15#include <sys/types.h>
16#include <ieeefp.h>
17
18#ifdef __weak_alias
19__weak_alias(fpsetround,_fpsetround)
20#endif
21
22#ifdef SOFTFLOATSPARC64_FOR_GCC
23extern fp_rnd _softfloat_float_rounding_mode;
24#endif
25
26fp_rnd
27fpsetround(fp_rnd rnd_dir)
28{
29	fp_rnd old;
30	fp_rnd new;
31
32	__asm("st %%fsr,%0" : "=m" (*&old));
33
34#ifdef SOFTFLOATSPARC64_FOR_GCC
35	_softfloat_float_rounding_mode = rnd_dir;
36#endif
37
38	new = old;
39	new &= ~(0x03U << 30);
40	new |= ((rnd_dir & 0x03U) << 30);
41
42	__asm("ld %0,%%fsr" : : "m" (*&new));
43
44	return ((uint32_t)old >> 30) & 0x03;
45}
46