xref: /minix3/lib/libc/arch/sparc64/gen/fpsetround.c (revision 84d9c625bfea59e274550651111ae9edfdc40fbd)
1 /*	$NetBSD: fpsetround.c,v 1.7 2013/10/28 01:06:36 mrg 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 1.7 2013/10/28 01:06:36 mrg 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
__weak_alias(fpsetround,_fpsetround)19 __weak_alias(fpsetround,_fpsetround)
20 #endif
21 
22 fp_rnd
23 fpsetround(fp_rnd rnd_dir)
24 {
25 	fp_rnd old;
26 	fp_rnd new;
27 #ifdef SOFTFLOATSPARC64_FOR_GCC
28 	extern fp_rnd _softfloat_float_rounding_mode;
29 #endif
30 
31 	__asm("st %%fsr,%0" : "=m" (*&old));
32 
33 #ifdef SOFTFLOATSPARC64_FOR_GCC
34 	_softfloat_float_rounding_mode = rnd_dir;
35 #endif
36 
37 	new = old;
38 	new &= ~(0x03 << 30);
39 	new |= ((rnd_dir & 0x03) << 30);
40 
41 	__asm("ld %0,%%fsr" : : "m" (*&new));
42 
43 	return ((uint32_t)old >> 30) & 0x03;
44 }
45