Re: [pcre-dev] JIT increase stack requirement for SVN 1295

On 19.03.2013 17:57, Zoltán Herczeg wrote:

> I am afraid it is not possible to tell where the jump is without
> narrowing the revision range.

The following table lists the stack sizes required by my system for
various PCRE SVN versions.

The stack is required for COMPILING (not matching) these patterns in JIT
mode:

(a)(?2){0,1999}?(b)
(a)(?(DEFINE)(b))(?2){0,1999}?(?2)

Please note that there were 3 large increases in the development line
and one small decrease fairly recently.

SVN - Stack
==============
1243 - 660000
1244 - 730000
1245 - 730000
1246 - 730000
1253 - 730000
1267 - 730000
1276 - 730000
1277 - 860000 <- Large increase
1278 - 920000 <- Large increase
1279 - 1180000 <- Large increase
1280 - 1180000
1285 - 1180000
1289 - 1180000
1290 - 1120000 <- Small decrease
1295 - 1120000
1303 - 1120000

> Can you precisely measure the stack size?

Unfortunately no. The above numbers are as precisely as I can measure.
They include the overall stack size of PCRE and test environment.
However, the application is unchanged between PCRE versions so the
increase / decrease is due to PCRE only.

I hope this helps you to track down what could cause the increase in
stack size - and possibly reduce it.

Many thanks,

Ralf