80 lines
1.6 KiB
Rust
80 lines
1.6 KiB
Rust
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// -*- rust -*-
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/*
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A parallel version of fibonacci numbers.
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This version is meant mostly as a way of stressing and benchmarking
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the task system. It supports a lot of command-line arguments to
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control how it runs.
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*/
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use std;
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import std::vec;
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import std::uint;
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import std::time;
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import std::str;
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import std::int::range;
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import std::io;
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fn recv[T](&port[T] p) -> T {
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let T x;
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p |> x;
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ret x;
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}
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fn fib(int n) -> int {
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fn pfib(chan[int] c, int n) {
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if (n == 0) {
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c <| 0;
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}
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else if (n <= 2) {
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c <| 1;
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}
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else {
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let port[int] p = port();
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auto t1 = spawn pfib(chan(p), n - 1);
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auto t2 = spawn pfib(chan(p), n - 2);
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c <| recv(p) + recv(p);
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}
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}
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let port[int] p = port();
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auto t = spawn pfib(chan(p), n);
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ret recv(p);
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}
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fn main(vec[str] argv) {
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if(vec::len(argv) == 1u) {
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assert (fib(8) == 21);
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assert (fib(15) == 610);
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log fib(8);
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log fib(15);
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}
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else {
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// Interactive mode! Wooo!!!!
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auto max = uint::parse_buf(str::bytes(argv.(1)), 10u) as int;
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auto num_trials = 10;
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auto out = io::stdout();
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for each(int n in range(1, max + 1)) {
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for each(int i in range(0, num_trials)) {
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auto start = time::precise_time_ns();
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auto fibn = fib(n);
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auto stop = time::precise_time_ns();
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auto elapsed = (stop - start) as int;
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out.write_line(#fmt("%d\t%d\t%d", n, fibn, elapsed));
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}
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}
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}
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}
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