xref: /freebsd/lib/libc/amd64/gen/_setjmp.S (revision 1843dfb05ed80149f5a412180af882e3cb8f451b)
1/*-
2 * Copyright (c) 1990 The Regents of the University of California.
3 * All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * William Jolitz.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of the University nor the names of its contributors
17 *    may be used to endorse or promote products derived from this software
18 *    without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33#if defined(LIBC_SCCS) && !defined(lint)
34	.asciz "@(#)_setjmp.s	5.1 (Berkeley) 4/23/90"
35#endif /* LIBC_SCCS and not lint */
36#include <machine/asm.h>
37/*
38 * C library -- _setjmp, _longjmp
39 *
40 *	_longjmp(a,v)
41 * will generate a "return(v)" from the last call to
42 *	_setjmp(a)
43 * by restoring registers from the environment 'a'.
44 * The previous signal state is NOT restored.
45 */
46
47ENTRY(_setjmp)
48	movq	%rdi,%rax
49	movq	0(%rsp),%rdx		/* return address */
50	movq	%rdx, 0(%rax)		/* 0; return address */
51	movq	%rbx, 8(%rax)		/* 1; rbx */
52	movq	%rsp,16(%rax)		/* 2; rsp */
53	movq	%rbp,24(%rax)		/* 3; rbp */
54	movq	%r12,32(%rax)		/* 4; r12 */
55	movq	%r13,40(%rax)		/* 5; r13 */
56	movq	%r14,48(%rax)		/* 6; r14 */
57	movq	%r15,56(%rax)		/* 7; r15 */
58	fnstcw	64(%rax)		/* 8; fpu cw */
59	stmxcsr	68(%rax)		/*    and mxcsr */
60	xorq	%rax,%rax
61	ret
62END(_setjmp)
63
64	WEAK_REFERENCE(___longjmp, _longjmp)
65ENTRY(___longjmp)
66	movq	%rdi,%rdx
67	/* Restore the mxcsr, but leave exception flags intact. */
68	stmxcsr	-4(%rsp)
69	movl	68(%rdx),%eax
70	andl	$0xffffffc0,%eax
71	movl	-4(%rsp),%edi
72	andl	$0x3f,%edi
73	xorl	%eax,%edi
74	movl	%edi,-4(%rsp)
75	ldmxcsr -4(%rsp)
76	movq	%rsi,%rax		/* retval */
77	movq	0(%rdx),%rcx
78	movq	8(%rdx),%rbx
79	movq	16(%rdx),%rsp
80	movq	24(%rdx),%rbp
81	movq	32(%rdx),%r12
82	movq	40(%rdx),%r13
83	movq	48(%rdx),%r14
84	movq	56(%rdx),%r15
85	fldcw	64(%rdx)
86	testq	%rax,%rax
87	jnz	1f
88	incq	%rax
891:	movq	%rcx,0(%rsp)		/* return address */
90	ret
91END(___longjmp)
92
93	.section .note.GNU-stack,"",%progbits
94