wp-includes/category-template.php:795Default topic count scaling for tag links.
$countintintfunction default_topic_count_scale( $count ) { return (int) round( log10( $count + 1 ) * 100 );}Introduced in 2.9.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/category-template.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.