Optimize unmodified variables

This commit is contained in:
alexlamsl
2016-09-20 22:23:27 +08:00
committed by Richard van Velzen
parent 0111497fc9
commit 4761d07e0b
4 changed files with 184 additions and 5 deletions

View File

@@ -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 {

View File

@@ -197,7 +197,8 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(options){
}
if (node instanceof AST_SymbolRef) {
var name = node.name;
if (name == "eval" && tw.parent() instanceof AST_Call) {
var parent = tw.parent();
if (name == "eval" && parent instanceof AST_Call) {
for (var s = node.scope; s && !s.uses_eval; s = s.parent_scope) {
s.uses_eval = true;
}
@@ -213,12 +214,15 @@ AST_Toplevel.DEFMETHOD("figure_out_scope", function(options){
g.global = true;
globals.set(name, g);
}
node.thedef = g;
sym = g;
if (func && name == "arguments") {
func.uses_arguments = true;
}
} else {
node.thedef = sym;
}
node.thedef = sym;
if (parent instanceof AST_Unary && (parent.operator === '++' || parent.operator === '--')
|| parent instanceof AST_Assign && parent.left === node) {
sym.modified = true;
}
node.reference();
return true;