2.11BSD#431 - /usr/src/lib/libc/pdp/gen/insque.s

   1: /*
   2:  * Copyright (c) 1987 Regents of the University of California.
   3:  * All rights reserved.  The Berkeley software License Agreement
   4:  * specifies the terms and conditions for redistribution.
   5:  */
   6: 
   7: #ifdef LIBC_SCCS
   8:         <@(#)insque.s	1.2 (Berkeley) 1/20/87\0>
   9:         .even
  10: #endif LIBC_SCCS
  11: 
  12: /*
  13:  * struct qelem
  14:  * {
  15:  *	struct qelem	*q_forw;
  16:  *	struct qelem	*q_back;
  17:  *	char		q_data[];
  18:  * }
  19:  *
  20:  * insque (elem, pred)
  21:  *   struct qelem  *elem, *pred
  22:  *
  23:  * Insert elem into queue with predecessor pred.
  24:  */
  25: #include "DEFS.h"
  26: 
  27: ENTRY(insque)
  28:         mov     2(sp),r0        / r0 = elem
  29:         mov     4(sp),r1        / r1 = pred
  30:         mov     r1, 2(r0)       / elem->q_back = pred
  31:         mov     (r1),(r0)       / elem->q_forw = pred->q_forw
  32:         mov     r0,(r1)         / pred->q_forw = elem
  33:         mov     (r0),r1         / r1 = elem->q_forw  /* was pred->q_forw */
  34:         mov     r0,2(r1)        / elem->q_forw->q_back = elem
  35:         rts     pc

Defined functions