re PR middle-end/30509 (ice for legal code with -O3)

	PR middle-end/30509
	* tree-inline.c (copy_bb): Produce exact copy of EH info when copying for inlining.

From-SVN: r122314

gcc/ChangeLog

+2007-02-24  Jan Hubicka  <jh@suse.cz>
+
+	PR middle-end/30509
+	* tree-inline.c (copy_bb): Produce exact copy of EH info when copying for inlining.
+
 2007-02-24  Uros Bizjak  <ubizjak@gmail.com>
 	    Jan Hubicka  <jh@suse.cz>
 

gcc/tree-inline.c

@@ -873,7 +873,20 @@ copy_bb (copy_body_data *id, basic_block bb, int frequency_scale, int count_scal
 	      gcc_assert (lookup_stmt_eh_region_fn (id->src_cfun, orig_stmt)
 			  != 0);
 
-	      if (tree_could_throw_p (stmt))
+	      if (tree_could_throw_p (stmt)
+		  /* When we are cloning for inlining, we are supposed to
+		     construct a clone that calls precisely the same functions
+		     as original.  However IPA optimizers might've proved
+		     earlier some function calls as non-trapping that might
+		     render some basic blocks dead that might become
+		     unreachable.
+
+		     We can't update SSA with unreachable blocks in CFG and thus
+		     we prevent the scenario by preserving even the "dead" eh
+		     edges until the point they are later removed by
+		     fixup_cfg pass.  */
+		  || (id->transform_call_graph_edges == CB_CGE_MOVE_CLONES
+		      && lookup_stmt_eh_region_fn (id->src_cfun, orig_stmt) > 0))
 		{
 		  int region = lookup_stmt_eh_region_fn (id->src_cfun, orig_stmt);
 		  /* Add an entry for the copied tree in the EH hashtable.