usr/src/lib/libc/tahoe/gen/alloca.s

/*
 * Copyright (c) 1988 Regents of the University of California.
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Computer Consoles Inc.
 *
 * %sccs.include.redist.c%
 */

#if defined(LIBC_SCCS) && !defined(lint)
        .asciz "@(#)alloca.s    5.1 (Berkeley) %G%"
#endif /* LIBC_SCCS and not lint */

/* like alloc, but automatic automatic free in return */

#include "DEFS.h"

ENTRY(alloca, 0)
        moval   (sp),r0         # current sp
        subl2   4(fp),r0        # allocation size
        andl2   $0xfffffffc,r0  # allignment
        movl    -8(fp),r1       # old pc
        movl    (fp),fp         # old fp
        addl2   $4*4,r0         # reuse space of mscp
        movl    r0,sp           # new sp
        jmp     (r1)            # funny return