[Libre-soc-dev] SVP64 parallel map-reduce idea

[Jacob Lifshay]

On Fri, Jun 11, 2021, 16:32 Luke Kenneth Casson Leighton <lkcl at lkcl.net>
wrote:

> ah, star.  it's quite late, i'm going to have to read it several times,
> possibly even make it executable and print out some "results"
> (plus indices) to get it fully.


from your comments I can tell you didn't understand the algorithm yet...
well...it is executable, you can use that rust playground link to run it,
it just needs a main function (added in new link below):
https://play.rust-lang.org/?version=stable&mode=debug&edition=2018&gist=9cbe5d650a088fb8558f2387c2758cb3

I added some debugging print statements and a main function which calls it
twice, once with both a all-true predicate and once with a predicate which
demonstrates that not all adds are performed, even after the first layer:

fn main() {
    const VL: usize = 8;
    let input_vec: [f32; VL] = [1.0, 2.0, 4.0, 10.0, 20.0, 40.0, 100.0,
200.0];
    let mut temp_vec = [f32::NAN; VL];
    let input_pred: [bool; VL] = [true, true, true, false, false, false,
true, true];
    let mut temp_pred = [true; VL];
    let retval = reduce(VL, &input_vec, &mut temp_vec, &input_pred, &mut
temp_pred);
    println!(
        "temp_pred={:?}\ntemp_vec={:?}\nretval={:?}\n",
        temp_pred, temp_vec, retval
    );
    let input_vec: [f32; VL] = [1.0, 2.0, 4.0, 10.0, 20.0, 40.0, 100.0,
200.0];
    let mut temp_vec = [f32::NAN; VL];
    let input_pred = [true; VL];
    let mut temp_pred = [true; VL];
    let retval = reduce(VL, &input_vec, &mut temp_vec, &input_pred, &mut
temp_pred);
    println!(
        "temp_pred={:?}\ntemp_vec={:?}\nretval={:?}\n",
        temp_pred, temp_vec, retval
    );
}

Jacob