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Date: Fri, 18 Apr 2008 09:26:22 -0500
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Subject: [PATCH] No runtime fetching of built-in global constants
From: php_lists@realplain.com ("Matt Wilmas")

Hi all,

I changed things so that the many "built-in" constants (CONST_PERSISTENT
ones) will be replaced at compile-time, saving the FETCH_CONSTANT opcode, if
these changes are usable.  This was added for TRUE/FALSE/NULL 2 years ago,
but seems like it can be done for "lots" of others too.

Since the change 2 years ago, other constants have been getting looked up
also, but just discarded.  And if a constant wasn't found, its name was
lowercased and looked up again (for case-insensitive TRUE/FALSE/NULL).
Lowercasing has been removed, since case-insensitive constants can't be done
(guess an exception was made for TRUE/FALSE/NULL :-)), and TRUE/FALSE/NULL
get flagged in the scanner (not reserved words, which Marcus did briefly a
few years ago), skipping a hash lookup.  BTW, to get this compile-time
optimization in a namespace, it needs to be prefixed (::CONSTANT).

I also removed an unnecessary memcmp() in zend_get_constant() -- old code
that was needed a long time ago, it appears.

http://realplain.com/php/const_ct_optimization.diff
http://realplain.com/php/const_ct_optimization_5_3.diff

Thoughts?


Thanks,
Matt