PR middle-end/67133

	* gimple-ssa-isolate-paths.c
	(insert_trap_and_remove_trailing_statements): Rename to ...
	(insert_trap): ... this.  Don't remove trailing statements; split
	block instead.
	(find_explicit_erroneous_behaviour): Don't remove all outgoing edges.

	* g++.dg/torture/pr67133.C: New test.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@227009 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 7 insertions, 23 deletions

diff --git a/gcc/gimple-ssa-isolate-paths.c b/gcc/gimple-ssa-isolate-paths.c
index 6f84f85856b..ca2322d1346 100644
--- a/gcc/gimple-ssa-isolate-paths.c
+++ b/gcc/gimple-ssa-isolate-paths.c
@@ -66,10 +66,10 @@ check_loadstore (gimple stmt, tree op, tree, void *data)
   return false;
 }
 
-/* Insert a trap after SI and remove SI and all statements after the trap.  */
+/* Insert a trap after SI and split the block after the trap.  */
 
 static void
-insert_trap_and_remove_trailing_statements (gimple_stmt_iterator *si_p, tree op)
+insert_trap (gimple_stmt_iterator *si_p, tree op)
 {
   /* We want the NULL pointer dereference to actually occur so that
      code that wishes to catch the signal can do so.
@@ -115,18 +115,8 @@ insert_trap_and_remove_trailing_statements (gimple_stmt_iterator *si_p, tree op)
   else
     gsi_insert_before (si_p, seq, GSI_NEW_STMT);
 
-  /* We must remove statements from the end of the block so that we
-     never reference a released SSA_NAME.  */
-  basic_block bb = gimple_bb (gsi_stmt (*si_p));
-  for (gimple_stmt_iterator si = gsi_last_bb (bb);
-       gsi_stmt (si) != gsi_stmt (*si_p);
-       si = gsi_last_bb (bb))
-    {
-      stmt = gsi_stmt (si);
-      unlink_stmt_vdef (stmt);
-      gsi_remove (&si, true);
-      release_defs (stmt);
-    }
+  split_block (gimple_bb (new_stmt), new_stmt);
+  *si_p = gsi_for_stmt (stmt);
 }
 
 /* BB when reached via incoming edge E will exhibit undefined behaviour
@@ -215,7 +205,7 @@ isolate_path (basic_block bb, basic_block duplicate,
 	  update_stmt (ret);
 	}
       else
-	insert_trap_and_remove_trailing_statements (&si2, op);
+	insert_trap (&si2, op);
     }
 
   return duplicate;
@@ -422,14 +412,8 @@ find_explicit_erroneous_behaviour (void)
 		    continue;
 		}
 
-	      insert_trap_and_remove_trailing_statements (&si,
-							  null_pointer_node);
-
-	      /* And finally, remove all outgoing edges from BB.  */
-	      edge e;
-	      for (edge_iterator ei = ei_start (bb->succs);
-		   (e = ei_safe_edge (ei)); )
-		remove_edge (e);
+	      insert_trap (&si, null_pointer_node);
+	      bb = gimple_bb (gsi_stmt (si));
 
 	      /* Ignore any more operands on this statement and
 		 continue the statement iterator (which should