Index: tree-inline.c
===================================================================
--- tree-inline.c	(revision 222439)
+++ tree-inline.c	(working copy)
@@ -898,7 +898,19 @@ remap_gimple_op_r (tree *tp, int *walk_s
 
   if (TREE_CODE (*tp) == SSA_NAME)
     {
-      *tp = remap_ssa_name (*tp, id);
+      tree t = remap_ssa_name (*tp, id);
+      /* Perform anonymous constant propagation, this makes it possible to
+         generate reasonable code even at -O0 for operators implemented as
+         inline functions.  */
+      if (TREE_CODE (t) == SSA_NAME
+	  && SSA_NAME_DEF_STMT (t)
+	  && (!SSA_NAME_VAR (t) || DECL_IGNORED_P (SSA_NAME_VAR (t)))
+	  && gimple_assign_copy_p (SSA_NAME_DEF_STMT (t))
+	  && is_gimple_min_invariant
+	     (gimple_assign_rhs1 (SSA_NAME_DEF_STMT (t))))
+	*tp = gimple_assign_rhs1 (SSA_NAME_DEF_STMT (t));
+      else
+	*tp = t;
       *walk_subtrees = 0;
       return NULL;
     }
@@ -1965,7 +1977,7 @@ copy_bb (copy_body_data *id, basic_block
 
 	  /* Statements produced by inlining can be unfolded, especially
 	     when we constant propagated some operands.  We can't fold
-	     them right now for two reasons:
+	     them right now in the general case for two reasons:
 	     1) folding require SSA_NAME_DEF_STMTs to be correct
 	     2) we can't change function calls to builtins.
 	     So we just mark statement for later folding.  We mark
@@ -1974,7 +1986,10 @@ copy_bb (copy_body_data *id, basic_block
 	     foldable indirectly are updated.  If this turns out to be
 	     expensive, copy_body can be told to watch for nontrivial
 	     changes.  */
-	  if (id->statements_to_fold)
+	  if (gimple_assign_cast_p (stmt)
+	      && is_gimple_min_invariant (gimple_assign_rhs1 (stmt)))
+	    fold_stmt (&copy_gsi);
+	  else if (id->statements_to_fold)
 	    id->statements_to_fold->add (stmt);
 
 	  /* We're duplicating a CALL_EXPR.  Find any corresponding