Basic variables uses are now propagated like constants to save stack space

phases/constprop.ml

@@ -21,7 +21,10 @@ open Util
 let is_const_name name =
   Str.string_match (Str.regexp "^.+\\$\\$[0-9]+$") name 0
 
-let is_const = function Const _ -> true | _ -> false
+let is_const = function
+  | Const _
+  | VarUse (_, None, _) -> true
+  | _ -> false
 
 (* Play-it-safe side effect analysis: only return true for variables and
  * constants, since these are targeted in arithmetic simplification (in