PHP how to detect if running on arm64 cpu?

PHP Snippet 1:

// have been in a situation where MacOS-php says 
// "arm64" while php-in-docker-linux-container-running-on-macos
// says "aarch64"...
$isArm64 = (false!==stripos(php_uname("m"), "aarch64") || false!== stripos(php_uname("m"),"arm64"));