Re: [RFC] Constant Scalar Expressions

On Wed, 14 Aug 2013, Anthony Ferrara wrote: > Sebastian, > > > On Wed, Aug 14, 2013 at 7:44 AM, Sebastian Krebs <krebs.seb@gmail.com>wrote: > > > Just asking: Does this cover only declarations, or every constant > > expression, for example > > > > $weeks = $secs / (60 * 60 * 24 * 7); > > > > becomes to the opcode-equivalent of > > > > $weeks = $secs / (604800); A week isn't always 7 * 24 hours... > Currently, only places that use the static_scalar parser definition will > use this: > http://lxr.php.net/xref/PHP_TRUNK/Zend/zend_language_parser.y#945 > > So today that's constants (using const keyword), class constants, class > properties, function parameter values and declare statements. > > To do the other part would likely need to happen in the compiler itself > (look for all opcodes of type _SPEC_CONST_CONST, and then optimize those > away). I will experiment a bit, but my gut tells me it will result in a lot > of parser or compiler complexity to attempt to do that (for which there > will be so little gain, as the runtime performance is already quite > fast)... At which point the complexity isn't worth it. Perhaps something for OpCache's optimizer though, if it doesn't already do that... cheers, Derick -- http://derickrethans.nl | http://xdebug.org Like Xdebug? Consider a donation: http://xdebug.org/donate.php twitter: @derickr and @xdebug Posted with an email client that doesn't mangle email: alpine