[PATCH/RFA] Updated patch to fix VAX casesi

[Jason R Thorpe]

This is an update of Richard's patch to fix casesi on VAX.  The
change from the original is to check for NULL note in
force_nonfallthru_and_redirect() as was discussed in a follow-up
message.

This has been bootstrapped on vax-netbsdelf, and I'm bootstrapping it
on i386-netbsdelf right now as a sanity check.

OK to checkin if bootstrap succeeds?

2002-06-21  Richard Henderson  <rth@redhat.com>

	* bb-reorder.c (make_reorder_chain_1): Search harder for the
	vax casesi fallthru edge.
	* cfglayout.c (cleanup_unconditional_jumps): Use
	redirect_edge_succ_nodup.  Do not delete ADDR_VEC insns as dead.
	* cfgrtl.c (force_nonfallthru_and_redirect): Place redirection
	block after ADDR_VEC.

-- 
        -- Jason R. Thorpe <thorpej@wasabisystems.com>
-------------- next part --------------
Index: bb-reorder.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/bb-reorder.c,v
retrieving revision 1.49
diff -c -r1.49 bb-reorder.c
*** bb-reorder.c	26 May 2002 15:01:11 -0000	1.49
--- bb-reorder.c	21 Jun 2002 18:20:13 -0000
***************
*** 209,224 ****
    /* In the absence of a prediction, disturb things as little as possible
       by selecting the old "next" block from the list of successors.  If
       there had been a fallthru edge, that will be the one.  */
    if (! next)
      {
        for (e = bb->succ; e ; e = e->succ_next)
! 	if (e->dest == bb->next_bb)
  	  {
! 	    if ((e->flags & EDGE_FALLTHRU)
! 	        || (e->dest->succ
! 	            && ! (e->flags & (EDGE_ABNORMAL_CALL | EDGE_EH))))
! 	      next = e->dest;
  	    break;
  	  }
      }
  
--- 209,228 ----
    /* In the absence of a prediction, disturb things as little as possible
       by selecting the old "next" block from the list of successors.  If
       there had been a fallthru edge, that will be the one.  */
+   /* Note the special exception of the VAX casesi fallthru, which may not
+      have been next, but should be selected, if possible.  */
    if (! next)
      {
        for (e = bb->succ; e ; e = e->succ_next)
! 	if (e->flags & EDGE_FALLTHRU)
  	  {
! 	    next = e->dest;
  	    break;
+ 	  }
+ 	else if (e->dest == bb->next_bb)
+ 	  {
+ 	    if (! (e->flags & (EDGE_ABNORMAL_CALL | EDGE_EH)))
+ 	      next = e->dest;
  	  }
      }
  
Index: cfglayout.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/cfglayout.c,v
retrieving revision 1.20
diff -c -r1.20 cfglayout.c
*** cfglayout.c	21 Jun 2002 02:09:10 -0000	1.20
--- cfglayout.c	21 Jun 2002 18:20:14 -0000
***************
*** 608,617 ****
  }
  
  /* Remove any unconditional jumps and forwarder block creating fallthru
!    edges instead.  During BB reordering fallthru edges are not required
     to target next basic block in the linear CFG layout, so the unconditional
!    jumps are not needed.  If LOOPS is not null, also update loop structure &
!    dominators.  */
  
  static void
  cleanup_unconditional_jumps ()
--- 608,616 ----
  }
  
  /* Remove any unconditional jumps and forwarder block creating fallthru
!    edges instead.  During BB reordering, fallthru edges are not required
     to target next basic block in the linear CFG layout, so the unconditional
!    jumps are not needed.  */
  
  static void
  cleanup_unconditional_jumps ()
***************
*** 636,642 ****
  		fprintf (rtl_dump_file, "Removing forwarder BB %i\n",
  			 bb->index);
  
! 	      redirect_edge_succ (bb->pred, bb->succ->dest);
  	      flow_delete_block (bb);
  	      bb = prev;
  	    }
--- 635,641 ----
  		fprintf (rtl_dump_file, "Removing forwarder BB %i\n",
  			 bb->index);
  
! 	      redirect_edge_succ_nodup (bb->pred, bb->succ->dest);
  	      flow_delete_block (bb);
  	      bb = prev;
  	    }
***************
*** 653,660 ****
  	  else
  	    continue;
  
- 	  /* Cleanup barriers and delete ADDR_VECs in a way as they are belonging
-              to removed tablejump anyway.  */
  	  insn = NEXT_INSN (bb->end);
  	  while (insn
  		 && (GET_CODE (insn) != NOTE
--- 652,657 ----
***************
*** 664,675 ****
  
  	      if (GET_CODE (insn) == BARRIER)
  		delete_barrier (insn);
- 	      else if (GET_CODE (insn) == JUMP_INSN)
- 		delete_insn_chain (PREV_INSN (insn), insn);
- 	      else if (GET_CODE (insn) == CODE_LABEL)
- 		;
- 	      else if (GET_CODE (insn) != NOTE)
- 		abort ();
  
  	      insn = next;
  	    }
--- 661,666 ----
Index: cfgrtl.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/cfgrtl.c,v
retrieving revision 1.57
diff -c -r1.57 cfgrtl.c
*** cfgrtl.c	11 Jun 2002 12:21:31 -0000	1.57
--- cfgrtl.c	21 Jun 2002 18:20:16 -0000
***************
*** 963,971 ****
    if (e->src->succ->succ_next)
      {
        /* Create the new structures.  */
        note = last_loop_beg_note (e->src->end);
!       jump_block
! 	= create_basic_block (NEXT_INSN (note), NULL, e->src);
        jump_block->count = e->count;
        jump_block->frequency = EDGE_FREQUENCY (e);
        jump_block->loop_depth = target->loop_depth;
--- 963,983 ----
    if (e->src->succ->succ_next)
      {
        /* Create the new structures.  */
+ 
+       /* Position the new block correctly relative to loop notes.  */
        note = last_loop_beg_note (e->src->end);
!       note = NEXT_INSN (note);
! 
!       /* ... and ADDR_VECs.  */
!       if (note != NULL
! 	  && GET_CODE (note) == CODE_LABEL
! 	  && NEXT_INSN (note)
! 	  && GET_CODE (NEXT_INSN (note)) == JUMP_INSN
! 	  && (GET_CODE (PATTERN (NEXT_INSN (note))) == ADDR_DIFF_VEC
! 	      || GET_CODE (PATTERN (NEXT_INSN (note))) == ADDR_VEC))
! 	note = NEXT_INSN (NEXT_INSN (note));
! 
!       jump_block = create_basic_block (note, NULL, e->src);
        jump_block->count = e->count;
        jump_block->frequency = EDGE_FREQUENCY (e);
        jump_block->loop_depth = target->loop_depth;