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DAVEM TPF grant#2 report #66, #67, #68

From:
Dave Mitchell
Date:
February 24, 2015 11:18
Subject:
DAVEM TPF grant#2 report #66, #67, #68
Message ID:
20150224111839.GF28599@iabyn.com
(whoops, another report that covers three weeks)

Haven't done a vast amount recently; I worked on a few tickets and tried to
keep up with my p5p inbox. I was mostly spending my time working on the
OP_SIGNATURE stuff under separate funding (thanks, booking.com!).

The main ticket I worked on, #123743, concerned regexes going quadratic
that start with /.*/ . These are special-cased to avoid quadratic-ness,
but it turns out that when the pattern is intuitable (has a fixed or
floating constant substring for quick rejection or determination of
earliest possible start position), the intuit interfered with the
special-casing, causing the pattern to go quadratic. An optimisation in
5.18.0, that made some //i patterns intuitable, indirectly caused a bunch
of /.*.../i pattens to go quadratic too. Now fixed.


2015/02/02
     1:42 process p5p mailbox
     0:07 [perl #123685] Question regarding the '#!' argument passing.
     2:01 make last op_sibling point to parent
     
2015/02/04
     0:07 process p5p mailbox

# ----

2015/02/09
     5:13 [perl #123743] RegEx ".*" Backtracking slow since 5.18 (maybe 5.17.?)

2015/02/10
     3:23 [perl #123743] RegEx ".*" Backtracking slow since 5.18 (maybe 5.17.?)
     2:14 process p5p mailbox

2015/02/11
     0:42 process p5p mailbox

2015/02/12
     0:10 process p5p mailbox

2015/02/13
     0:40 process p5p mailbox

SUMMARY:
      0:07 [perl #123685] Question regarding the '#!' argument passing.
      8:36 [perl #123743] RegEx ".*" Backtracking slow since 5.18 (maybe 5.17.?)
      2:01 make last op_sibling point to parent
      5:35 process p5p mailbox
    ------
     16:19 TOTAL (HH::MM)


-- 
"I do not resent criticism, even when, for the sake of emphasis,
it parts for the time with reality".
    -- Winston Churchill, House of Commons, 22nd Jan 1941.



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