Re: [pcre-dev] JIT speed tests

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Autor: ND
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Dla: Pcre-dev
Temat: Re: [pcre-dev] JIT speed tests
On 2013-03-25 08:57, Zoltán Herczeg wrote:
> This is an exponential case for the code generator.>The code generator
> optimize these patterns one-by-one, and this process requires a lot of
> time and an enormous stack space. Where do you use such pattern? Can't
> you use a better pattern?
>

It's not a real pattern.
My application hardly uses callouts and all of backtracking verbs. Some
time ago I have a hope that if JIT starts to support callouts and all
backtracking verbs then it speeds up my application. Now You did this
changes to JIT engine (thanks alot). But when my application starts with
this PCRE build it deal all things much slo-o-o-o-wly.
I knows that JIT compilation time is much longer then interpreter. But I
be sure that this is not a problem because regular expressions can be
precompiled. I did't know nothing about PCRE can't precompile JIT data.
And only when I see a slowing of my application I found in documentation
this fact. I'm very disappointed...


> Ahead-of-time (AOT) compilation is not really useful in my experiences,
> because pointers are not known at compile time, and you need to replace
> them by costly memory reads and writes.

Are there this memory reads/writes more costly then JIT-recompiling?