Optimize unmodified variables

2016-09-20 22:23:27 +08:00
parent 0111497fc9
commit 4761d07e0b
4 changed files with 184 additions and 5 deletions
--- a/lib/compress.js
+++ b/lib/compress.js
@@ -67,6 +67,7 @@ function Compressor(options, false_by_default) {
        if_return     : !false_by_default,
        join_vars     : !false_by_default,
        collapse_vars : false,
+        reduce_vars   : false,
        cascade       : !false_by_default,
        side_effects  : !false_by_default,
        pure_getters  : false,
@@ -1107,7 +1108,7 @@ merge(Compressor.prototype, {
            this._evaluating = true;
            try {
                var d = this.definition();
-                if (d && d.constant && d.init) {
+                if (d && (d.constant || compressor.option("reduce_vars") && !d.modified) && d.init) {
                    return ev(d.init, compressor);
                }
            } finally {