diff_llvm_timings.php

<?php

// Extracting last timings as a convenience here,
// as we're usually interested in the last crate.
// We could also aggregate instead.
$metric = 'user_system';
$timings1 = parse_llvm_timing(extract_last_pass_timings(file_get_contents($argv[1])));
$timings2 = parse_llvm_timing(extract_last_pass_timings(file_get_contents($argv[2])));

$timings1 = array_column($timings1, null, 'name');
$timings2 = array_column($timings2, null, 'name');
$passes = array_keys(array_merge($timings1, $timings2));

$results = [];
foreach ($passes as $pass) {
    $time1 = $timings1[$pass][$metric] ?? null;
    $time2 = $timings2[$pass][$metric] ?? null;
    $diff = $time2 - $time1;
    $results[] = [
        'name' => $pass, 
        'old_time' => $time1,
        'new_time' => $time2,
        'diff' => $diff,
    ];
}

uasort($results, function($a, $b) {
    return abs($a['diff']) <=> abs($b['diff']);
});

foreach ($results as $result) {
    printf("%-60s  %s  %s  %s\n",
        $result['name'],
        format_time($result['old_time']),
        format_time($result['new_time']),
        format_time($result['diff']));
}

function format_time(?float $time): string {
    if ($time === null) {
        return ' ------';
    } else {
        return sprintf('%6.3fs', $time);
    }
}

function parse_llvm_timing(string $data): array {
    $time = '\d+\.\d+';
    $perc = '\(\s*\d+\.\d+%\)';
    $regex = <<<REGEX
/^\s+(?<user>$time)\s+$perc
\s+(?<system>$time)\s+$perc
\s+(?<user_system>$time)\s+$perc
\s+(?<wall>$time)\s+$perc
\s+(?<name>.+)$/xm
REGEX;
    if (!preg_match_all($regex, $data, $matches, PREG_SET_ORDER)) {
        throw new Exception('Nothing matches?');
    }
    $results = [];
    foreach ($matches as $match) {
        $results[] = [
            'name' => $match['name'],
            'user' => (float) $match['user'],
            'system' => (float) $match['system'],
            'user_system' => (float) $match['user_system'],
            'wall' => (float) $match['wall'],
        ];
    }
    return $results;
}

function extract_last_pass_timings(string $data): string {
    $separator = '... Pass execution timing report ...';
    $pos = strrpos($data, $separator);
    return substr($data, $pos);
}