Robert Cummings Ã*rta:
> On Sat, 2008-03-29 at 10:16 +0100, Zoltán Németh wrote:
>>> One last thing though...
>>> even if this were escaped and even if there were fifty variables
>>> embedded, a good bytecode optimizer (not quite the same as a bytecode
>>> cacher) would optimize the bytecode for caching so that the string is
>>> broken up according to what needs to be interpolated and what does not.
>> could you tell me more about this bytecode optimizer stuff? how does it
>> work, how much better/faster is it then APC/EAccelerator/etc?
>
> It really depends on what an optimizer optimizes. TurckMMCache had.has
> an optimizer. Zend offers an optimizer too. Optimizer can work in a
> number of ways. They may be an explicit part of the bytecode cache
> mechanism or possibly plugged as one element in a chain of bytecode
> processors... parser -> optmizer -> cacher. I'm not exactly sure how it
> works for PHP.
>
> The main difference between a cacher and an optimizer though is that
> generally speaking a caher only deals with caching the bytecode. No
> processing occurs on the produced bytecode. On the other hand an
> optimizer may perform alterates on the bytecodes to enhance speed.
>
> For example... by now most people on the list probably know that:
>
> ++$i;
>
> Is faster than:
>
> $i++;
>
> An optmizer might see $i++ and determine that the return value is not
> used and thus the operation can be changed from $i++ to ++$i. Smilarly,
> the optimizer might encounter the following expression:
>
> $foo = 1 << 8
>
> And reduce the constant expression (1 << 8) to (256). So the expression
> essentially becomes:
>
> $foo = 256
>
> Similarly if you take the following expression:
>
> $text = "There was an old man from Nantuckit\n"
> ."Who's sole possession was a bucket.\n"
> ."One day with a grin,\n"
> ."While scratching his chin\n"
> ."He thought, \"I think I'll build a rocket.\"\n";
>
> This could be optimized by removing concatenation operations and
> producing a single unified string within the bytecode.
>
> These are just basic optimizations obviously. Optimization is not a new
> thing, if you've ever used the -O flags when building a C program then
> you know that C compilers can also perform optimizations.
>
> Cheers,
> Rob.

thanks, I get the concept

greets,
Zoltán Németh