flow.c (reorder_basic_blocks): Account for barriers when writing over NEXT_INSN (last_bb->end).

	* flow.c (reorder_basic_blocks): Account for barriers when writing
	over NEXT_INSN (last_bb->end).
	(verify_flow_info): Add check for missing barriers.

From-SVN: r32545

gcc/ChangeLog

+
+2000-03-14  Jason Eckhardt  <jle@cygnus.com>
+	* flow.c (reorder_basic_blocks): Account for barriers when writing
+	over NEXT_INSN (last_bb->end).
+	(verify_flow_info): Add check for missing barriers.
+
 2000-03-14  Greg McGary  <gkm@gnu.org>
 
 	* c-lex.h (enum rid): Add RID_BOUNDED & RID_UNBOUNDED.

gcc/flow.c

@@ -5785,6 +5785,7 @@ set_block_num (insn, bb)
      and NOTE_INSN_BASIC_BLOCK
    - check that all insns are in the basic blocks 
    (except the switch handling code, barriers and notes)
+   - check that all returns are followed by barriers
 
    In future it can be extended check a lot of other stuff as well
    (reachability of basic blocks, life information, etc. etc.).  */
@@ -5988,6 +5989,12 @@ verify_flow_info ()
 	    }
 	}
 
+      if (GET_RTX_CLASS (GET_CODE (x)) == 'i'
+	  && GET_CODE (x) == JUMP_INSN
+	  && returnjump_p (x)
+	  && ! (NEXT_INSN (x) && GET_CODE (NEXT_INSN (x)) == BARRIER))
+	    fatal_insn ("Return not followed by barrier", x);
+
       x = NEXT_INSN (x);
     }
 
@@ -7759,7 +7766,18 @@ reorder_basic_blocks ()
 	}
     }
      
-  NEXT_INSN (BASIC_BLOCK (n_basic_blocks - 1)->end) = last_insn;
+    {
+      rtx xafter = skip_insns_between_block (BASIC_BLOCK (n_basic_blocks - 1),
+					     REORDER_SKIP_AFTER);
+      if (xafter)
+	NEXT_INSN (xafter) = last_insn;
+      else
+	abort();
+    }
+
+#ifdef ENABLE_CHECKING
+  verify_flow_info ();
+#endif
 
   for (i = 0; i < n_basic_blocks - 1; i++)
     {