[pcre-dev] JIT have very limited applicability

Good day!


As I trying to say some time ago, PCRE-JIT in most applications is
useless. It only slowing matching process.

Consider timings. In most real situations JIT compile+run time greatly
exceeds interpreter compile+run time.
Taking this into account there are very few circumstances when JIT brings
benefits to user:
- JIT compile+run time is less then interpreter run time (I think that
number of this cases is about a zero);
- pattern is reused many times in a row in VM, without use of other
patterns between (IMHO number of this cases is also about a zero).

So JIT without ability to use JIT-precompiled patterns have a ve-e-e-ry
limited applicability.
May be I'm err. Correct me please if so.

I propose add to JIT ability of saving JIT-compiled data. So full
precompiled pattern can be used by main application. This eliminates a JIT
compile time costs and allow to use a speed benefits of JIT in most cases.
I understand than compiled JIT-data saved on one platform probably can't
be used on other platforms. But it can be used by application then starts
on one platform with great effectiveness.


I take this opportunity to thank Phillip and Zoltan for large efforts and
great product.
Best regards.