diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 3dc292b9421..6f3504e5ec6 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+Mon Oct  4 02:12:41 1999  Mark Mitchell  <mark@codesourcery.com>
+
+	* tree.c (make_node): Set TREE_SIDE_EFFECTS for expressions that
+	are always have side-effects.
+
 Sun Oct  3 14:14:16 1999  Jeffrey A Law  (law@cygnus.com)
 
 	* cppinit.c (is_idchar initializer): Tighten tests for when
diff --git a/gcc/tree.c b/gcc/tree.c
index 25e2680e1b3..221afba5184 100644
--- a/gcc/tree.c
+++ b/gcc/tree.c
@@ -1078,6 +1078,27 @@ make_node (code)
     case 'c':
       TREE_CONSTANT (t) = 1;
       break;
+
+    case 'e':
+      switch (code)
+	{
+	case INIT_EXPR:
+	case MODIFY_EXPR:
+	case VA_ARG_EXPR:
+	case RTL_EXPR:
+	case PREDECREMENT_EXPR:
+	case PREINCREMENT_EXPR:
+	case POSTDECREMENT_EXPR:
+	case POSTINCREMENT_EXPR:
+	  /* All of these have side-effects, no matter what their
+	     operands are.  */
+	  TREE_SIDE_EFFECTS (t) = 1;
+	  break;
+	  
+	default:
+	  break;
+	}
+      break;
     }
 
   return t;