2011/10/17 Ilia Alshanetsky <i...@prohost.org>:
> Seems like a good patch, +1 from me on inclusion into 5.4/HEAD.
>
> On Fri, Oct 14, 2011 at 2:08 PM, Arnaud Le Blanc <arnaud...@gmail.com> wrote:
>> Hi,
>>
>> I've already posted this patch and it has since been reviewed and improved.
>> I'm re-posting it for discussion before eventually commiting it.
>>
>> The ternary operator always copies its second or third operand, which is very
>> slow compared to an if/else when the operand is an array for example:
>>
>> $a = range(0,9);
>>
>> // this takes 0.3 seconds here:
>>
>> for ($i = 0; $i < 5000000; ++$i) {
>> if (true) {
>> $b = $a;
>> } else {
>> $b = $a;
>> }
>> }
>>
>> // this takes 3.8 seconds:
>>
>> for ($i = 0; $i < 5000000; ++$i) {
>> $b = true ? $a : $a;
>> }
>>
>> I've tried to reduce the performance hit by avoiding the copy when possible
>> (patch attached).
>>
>> Benchmark:
>>
>> Without patch: (the numbers are the time taken to run the code a certain
>> amount of times)
>>
>> $int = 0;
>> $ary = array(1,2,3,4,5,6,7,8,9);
>>
>> true ? 1 : 0 0.124
>> true ? 1+0 : 0 0.109
>> true ? $ary : 0 2.020 !
>> true ? $int : 0 0.103
>> true ? ${'ary'} : 0 2.290 !
>> true ?: 0 0.091
>> 1+0 ?: 0 0.086
>> $ary ?: 0 2.151 !
>> ${'var'} ?: 0 2.317 !
>>
>> With patch:
>>
>> true ? 1 : 0 0.124
>> true ? 1+0 : 0 0.195
>> true ? $ary : 0 0.103
>> true ? $int : 0 0.089
>> true ? ${'ary'} : 0 0.103
>> true ?: 0 0.086
>> 1+0 ?: 0 0.159
>> $cv ?: 0 0.090
>> ${'var'} ?: 0 0.089
>>
>>
>> The array copying overhead is eliminated. There is however a slowdown in some
>> of the cases, but overall there is no completely unexpected performance hit
>> as
>> it is the case currently.
>>
>> What do you think ? Is there any objection ?
>>
>> Best regards,
>>
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>>
>
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>
+1 from me too.
--
Regards,
Felipe Pena
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