usr/src/lib/libc/hp300/gen/alloca.s

/*-
 * Copyright (c) 1990 The Regents of the University of California.
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * the Systems Programming Group of the University of Utah Computer
 * Science Department.
 *
 * %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 free in return */

#include "DEFS.h"

ENTRY(alloca)
        movl    sp@,a0          /* save return addr */
        movl    sp,d0           /* get current SP value */
        subl    sp@(4),d0       /* allocate requested space */
        andb    #~3,d0          /* longword align for efficiency */
        addql   #8,d0           /* reuse space of call frame */
        movl    d0,sp           /* set new SP value */
        lea     sp@(-4),sp      /* account for argument pop in caller */
        jmp     a0@             /* funny return */