loop optimization #757
loop optimization #757
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Could you profile whether its faster after the change? |
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| if ($arraysToProcess[$j]->isKeysSupersetOf($arraysToProcess[$i])) { | ||
| $arraysToProcess[$j] = $arraysToProcess[$j]->mergeWith($arraysToProcess[$i]); | ||
| array_splice($arraysToProcess, $i--, 1); | ||
| $arraysToProcessCount--; |
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this does change the loop limit boundary, if it desired, why is that correct, if not, I belive this can not improve performance
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This part can be reverted as I'm not sure it needs to do multiple iterations.
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But it is really faster than? Please provide microbenchmark which shows count(array) is really slower.
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the problem is not with the complexity O(1) of count(), the point is that referencing to where the array's length is stored tends to be slower than accessing data from a variable. This makes them meaningful in the loop.
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yes, it seems a little bit faster https://3v4l.org/i2dqh
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| // transform A & (B & C) to A & B & C | ||
| for ($i = 0; $i < count($types); $i++) { | ||
| for ($i = 0; $i < $typesCount; $i++) { |
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previously it was called in every loop iteration which would make it O(n) then I guess? AFAIK this one of the micro optimizations that also the EA Extended plugin for phpstorm suggests and it definitely makes sense IMO.
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well i accidentally clicked the wrong ;) |
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Thank you! |
Idea from #747