multinpnr.py

#!/usr/bin/env python3

import re
import sys
import time
import subprocess
import multiprocessing
import termplotlib as tpl
import numpy as np


def run_npnr(seed):
    args = [f"nextpnr-{sys.argv[2]}"] + sys.argv[3:] + ["--seed", str(seed)]
    lims = {}
    tars = {}
    p = subprocess.run(args, capture_output=True, check=False, text=True)
    for line in p.stderr.split("\n"):
        matches = re.search("Max frequency for clock\s*'([^']*)': ([\d\.]*) MHz "
                            "\([A-Z]* at ([\d\.]*) MHz\)", line)
        if matches is not None:
            clk = matches.group(1)
            lims[clk] = float(matches.group(2))
            tars[clk] = float(matches.group(3))
    return seed, lims, tars


def run_many(n=20):
    print(f"Running {n} seeds...", end='', flush=True)
    t0 = time.time()
    pool = multiprocessing.Pool()
    results = pool.map(run_npnr, range(n))
    t = time.time() - t0
    print(f" done in {t:.1f}s.")
    seeds = [r[0] for r in results]
    achieveds = [r[1] for r in results]
    targets = results[0][2]
    return targets, seeds, achieveds


def plot(target, achieved):
    fig = tpl.figure()
    lower = int(np.min(achieved))
    upper = int(np.ceil(np.max(achieved)))
    bins = int(upper - lower)
    counts, bin_edges = np.histogram(achieved, bins, range=(lower, upper))
    labels = [f"{x:.0f}MHz" for x in range(int(lower), int(upper))]
    fig.barh(counts, labels, max_width=40, bar_width=1, show_vals=True, force_ascii=False)
    fig.show()


def summarise(target, seeds, achieved):
    best_seed = seeds[np.argmax(achieved)]
    worst_seed = seeds[np.argmin(achieved)]
    print(f"Target {target:.2f}MHz, worst case {min(achieved):.2f}MHz "
          f"(seed {worst_seed}), "
          f"best case {max(achieved):.2f}MHz (seed {best_seed}).")
    n_good = sum(1 for a in achieved if a >= target)
    spread = np.max(achieved) - np.min(achieved)
    print(f"{n_good} above target ({n_good*100/len(seeds):.1f}%). "
          f"Mean {np.mean(achieved):.2f}MHz, "
          f"std. dev. {np.std(achieved):.2f}MHz, spread {spread:.2f}MHz.")

if __name__ == "__main__":
    targets, seeds, achieveds = run_many(int(sys.argv[1]))
    for clk in targets:
        target = targets[clk]
        achieved = [a[clk] for a in achieveds]
        print("Clock", clk)
        plot(target, achieved)
        summarise(target, seeds, achieved)