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for loops are much faster in ACF than lucee

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https://trycf.com/gist/8bdad9f1f6db1011630e02eae16d6eed/acf2021?theme=monokai

acf 2021

4778ms cfloop tag 1368 - for () 4496 cfloop script

lucee 5.3.10.120

2620ms cfloop tag 5980 for () 2265 cfloop script

Lucee 6.0.0.313

2662ms cfloop tag 5920 for () 2548 cfloop script

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  • 29 Oct 2024, 12:31 pm

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Michael Offner 1 November 2024 at 09:05

solution here is to further specialize the functionality.

One thing you need to be very carefully, ACF has some kind of cache that give you faster access on the last variable used.
Mean when you have a loop that only access one and the same variable in the same iteration, it is faster because of that cache, but when you have more than one it get slower because of the overhead of that cache.
Back then i did compare this to the “Volkswagen Dieselgate“ because it is optimized for testing, but not for real life. I have analysed a lot of code back then to find out if that kind of caching is beneficial in real life or not, my conclusion was, it is not. Looking at your test code you do exactly that,reading only “i“.

Zac Spitzer 29 October 2024 at 12:31
Edited

Zac Spitzer 10 May 2023 at 11:27

odd, I’m seeing the reverse locally with 5.3.10.136

1706ms 1883 for() 1275

the bytecode for cfloop is really optimised compared to the for loop

double d = d4; while (true) { if (bool1 ? ((d <= d5)) : ((d >= d5))) { paramPageContext.us().set(KeyConstants._X, Operator.plusRef(paramPageContext.us().get(KeyConstants._I), ConstantsDouble._1)); variableReference.set(d += d6); continue; } break; }

while for() is doing more gymnastics

for (; !(Operator.compare(paramPageContext.us().get(KeyConstants._I), paramPageContext.us().get(this.keys[0])) > 0); Operator.unaryPoPl(paramPageContext, KeyConstants._I, 1.0D)) paramPageContext.us().set(KeyConstants._X, Operator.plusRef(paramPageContext.us().get(KeyConstants._I), ConstantsDouble._1));

Pothys - MitrahSoft 10 May 2023 at 11:10
Edited

checked this issue with latest Lucee version 6.0.0.389-SNAPSHOT. Yes, using for loop & cfloop in lucee takes more time than ACF

Lucee 6.0.0.389-SNAPSHOT

cfloop tag - 2325ms for() loop - 1541 cfloop script - 1850

ACF-2018

cfloop tag - 254ms for() loop - 348 cfloop script - 1

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Created 10 May 2023 at 09:46
Updated 4 December 2024 at 21:06