Yes, it does beat -O3 C sometimes. I took code from diverse 'language speed' benchmarks from the internet and had to rearrange them to get -O3 to beat equivalent-looking JS (Node 25.8.1 w\ V8 14.1 and clang 21 on MBP3).

> What was that code?

literally:

``` function numericKernel(a, b, out, n) {

    for (let i = 0; i < n; i += 4) {

        out[i]     = a[i]     * b[i]     + 0.25;
        out[i + 1] = a[i + 1] * b[i + 1] + 0.25;
        out[i + 2] = a[i + 2] * b[i + 2] + 0.25;
        out[i + 3] = a[i + 3] * b[i + 3] + 0.25;

    }