xref: /openbsd/lib/libc/arch/amd64/gen/fpsetmask.S (revision a6445c1d)
1/*	$OpenBSD: fpsetmask.S,v 1.1 2004/01/28 01:44:45 mickey Exp $	*/
2/*	$NetBSD: fpsetmask.S,v 1.3 2002/06/12 19:17:22 fvdl Exp $	*/
3
4/*
5 * Written by Frank van der Linden at Wasabi Systems for NetBSD.
6 * Public domain.
7 */
8
9#include <machine/asm.h>
10
11/*
12 * XXX set both the x87 control word and the SSE mxcsr register.
13 * Applications should only set exception and round flags
14 * via the fp*() interface, otherwise the status words
15 * will get our of sync.
16 */
17
18#ifdef WEAK_ALIAS
19WEAK_ALIAS(fpsetmask, _fpsetmask)
20ENTRY(_fpsetmask)
21#else
22ENTRY(fpsetmask)
23#endif
24	fnstcw	-4(%rsp)
25	stmxcsr	-8(%rsp)
26	andl	$63,%edi
27	notl	%edi
28
29	movl	-4(%rsp),%edx
30	movl	%edx,%eax
31	andl	%edi,%edx
32	movl	%edx,-4(%rsp)
33
34	movl	-8(%rsp),%edx
35	roll	$7,%edi
36	andl	%edi,%edx
37	movl	%edx,-8(%rsp)
38
39	fldcw	-4(%rsp)
40	ldmxcsr	-8(%rsp)
41	andl	$63,%eax
42	ret
43