1. Always compile it in but leave undocumented #ifdefs in place for performance freaks. Those same performance freaks aren't going to care about the binary compatibility issue since they are the same people who build all their own stuff.
Note that breaking BC is not only about performance - one your build is not the same as mainstream PHP, you can't use any binary extension which would do anything non-performance-related - like interfacing some external system/library, debugging, profiling, testing, security and so on. Any commercial module won't be available for the user of this switch, and all open-source modules one'd have to build by oneself, which may be serious maintenance issue. I know there are a bunch of companies that compile PHP with their own options but still use commercial modules, including both performance and non-performance ones. They couldn't use this compile switch.
-- Stanislav Malyshev, Zend Software Architect [EMAIL PROTECTED] http://www.zend.com/ (408)253-8829 MSN: [EMAIL PROTECTED] -- PHP Internals - PHP Runtime Development Mailing List To unsubscribe, visit: http://www.php.net/unsub.php