Hi, Regarding ARRAY_SLICE(..., preserve_keys=false) my whole point was that the check for non-numeric key inputs is not necessary if preserve_keys is false. It should basically be analogue to array_values(), but of course respecting the offset and length boundaries.
One question regarding FAST_ZPP: Why is it not used more often, especially in the satndard libraries? Is there some particular drawback? I'd like to understand. Thanks, Ben ========== Original ========== From: Xinchen Hui <xinche...@zend.com> To: Benjamin Coutu <ben.co...@zeyos.com> Date: Tue, 20 Jan 2015 09:53:38 +0100 Subject: [PHP-DEV] Re: Improvements to array.c code base Hey: On Tue, Jan 20, 2015 at 4:30 PM, Benjamin Coutu <ben.co...@zeyos.com> wrote: > Hi Dmitry, > > I was doing some code review of ext/standard/array.c and have recognized some > potential for a few performance improvements: > > === ARRAY_SLICE(..., preserve_keys=false) === > > array_slice() can always construct a packed array if preserve_keys is false, > restricting it to inputs with packed flag does not make much sense. > Removing the check for packed inputs on line 2376 would improve performance > if used on non-packed inputs with the default preserve_keys=false. This is check for non-numeric key inputs > Furthermore, ZEND_HASH_FOREACH_VAL should be used instead of > ZEND_HASH_FOREACH_NUM_KEY_VAL on line 2379. yeah, I will fix it. > It also think range() should use FAST_ZPP as it is a basic language feature > (other languages even have extra operators for it, e.g. [0..10]) > > === RANGE(...) === > > range() always returns a numerically indexed array [0..count-1]. The > resulting array therefore should be constructed as a packed array > (ZEND_HASH_FILL_PACKED+ZEND_HASH_FILL_ADD instead of > zend_hash_next_index_insert_new). > > === ARRAY_FILL(start_key=0, ...) > === > > Just like with range(), array_fill() always returns a numerically indexed > array [0..count-1] if start_key is 0. In this special but very common case > the resulting array can be constructed as a packed array > (ZEND_HASH_FILL_PACKED+ZEND_HASH_FILL_ADD instead of > zend_hash_next_index_insert_new). > Another common case is for start_key to be 1. One could refine the proposed > packed-array branch to just set the first bucket to undefined in this case. > > === COUNT(...) === > > count() is so ubiquitous! Giving it an opcode and making it part of the VM > seams reasonable. > > Please let me know your thoughts. hmm, we currently do optimization based on profile against some real life apps, like wordpress. range and array_fill etc doesn't used very common.. so I didn't look into it.. thanks for the advise, I will take a look . thanks > > Cheers, > > Ben > > -- > > Benjamin Coutu > Zeyon Technologies Inc. > http://www.zeyos.com > -- PHP Internals - PHP Runtime Development Mailing List To unsubscribe, visit: http://www.php.net/unsub.php
