closure-microbenchmark.js

function outer(x) {
    var y;
    for (var i = 0; i < 10000000; i++) {
        y = inner();
    }
    function inner() {
        return x;
    }
    return inner();
}


while(true) {
    var start = Date.now();
    outer("test");
    print(Date.now() - start, "millis");
}

results.txt

### Rhino HEAD output

2220 millis
1846 millis
1796 millis
1859 millis
1862 millis
1860 millis
1861 millis
1874 millis
1857 millis
1858 millis

### Rhino-opt companion-scopes branch

288 millis
244 millis
199 millis
205 millis
155 millis
237 millis
150 millis
152 millis
157 millis
152 millis

### V8 (snapshot from last summer, new one didn't build)

88 millis
86 millis
89 millis
88 millis
87 millis
88 millis
88 millis
89 millis
87 millis
88 millis