Convert the i386 alloca(3) to the x86-64 ISA.
Alignment hack from: NetBSD
This commit is contained in:
parent
46c06a0c42
commit
f98a708c20
53
lib/libc/amd64/gen/alloca.S
Normal file
53
lib/libc/amd64/gen/alloca.S
Normal file
@ -0,0 +1,53 @@
|
||||
/*-
|
||||
* Copyright (c) 1990 The Regents of the University of California.
|
||||
* All rights reserved.
|
||||
*
|
||||
* This code is derived from software contributed to Berkeley by
|
||||
* William Jolitz.
|
||||
*
|
||||
* Redistribution and use in source and binary forms, with or without
|
||||
* modification, are permitted provided that the following conditions
|
||||
* are met:
|
||||
* 1. Redistributions of source code must retain the above copyright
|
||||
* notice, this list of conditions and the following disclaimer.
|
||||
* 2. Redistributions in binary form must reproduce the above copyright
|
||||
* notice, this list of conditions and the following disclaimer in the
|
||||
* documentation and/or other materials provided with the distribution.
|
||||
* 3. All advertising materials mentioning features or use of this software
|
||||
* must display the following acknowledgement:
|
||||
* This product includes software developed by the University of
|
||||
* California, Berkeley and its contributors.
|
||||
* 4. Neither the name of the University nor the names of its contributors
|
||||
* may be used to endorse or promote products derived from this software
|
||||
* without specific prior written permission.
|
||||
*
|
||||
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
|
||||
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
||||
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
||||
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
|
||||
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
||||
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
||||
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
||||
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
||||
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
||||
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
||||
* SUCH DAMAGE.
|
||||
*/
|
||||
|
||||
#if defined(LIBC_SCCS) && !defined(lint)
|
||||
.asciz "@(#)alloca.s 5.2 (Berkeley) 5/14/90"
|
||||
#endif /* LIBC_SCCS and not lint */
|
||||
#include <machine/asm.h>
|
||||
__FBSDID("$FreeBSD$");
|
||||
|
||||
|
||||
/* like alloc, but automatic automatic free in return */
|
||||
|
||||
ENTRY(alloca)
|
||||
popq %rdx /* pop return addr */
|
||||
movl %rsp,%rcx
|
||||
addq $15,%rdi /* round amount to allocate up to 16 bytes */
|
||||
andq $~15,%rdi
|
||||
subq %rdi,%rsp
|
||||
movq %rsp,%rax /* base of newly allocated space */
|
||||
jmp *%rdx /* "return" */
|
Loading…
Reference in New Issue
Block a user