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

/*-
 * Copyright (c) 1991, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * %sccs.include.redist.c%
 */

#if defined(LIBC_SCCS) && !defined(lint)
        .asciz "@(#)alloca.s    8.1 (Berkeley) %G%"
#endif /* LIBC_SCCS and not lint */

#include "DEFS.h"

ENTRY(alloca, 0)
        movl    4(ap),r0        # get allocation size
        movl    16(fp),r2       # save return address before we smash it
        movab   here,16(fp)
        ret
here:
        subl2   r0,sp           # create stack space
        bicl2   $3,sp           # align to longword boundary
        movl    sp,r0
        jmp     (r2)