Performance analysis (trunk repository)
---------------------------------------

Jun 7, 2010: delayed re-typing of Ltac instances in matching
  (-1% on HighSchoolGeometry, -2% on JordanCurveTheorem)

Jun 4, 2010: improvement in eauto and type classes inference by removing
  systematic preparation of debugging pretty-printing streams (std_ppcmds)
  (-7% in ATBR, visible only on V8.3 logs since ATBR is broken in trunk;
   -6% in HighSchoolGeometry)

Apr 19, 2010: small improvement obtained by reducing evar instantiation 
  from O(n^3) to O(n^2) in the size of the instance (-2% in Compcert,
  -2% AreaMethod, -15% in Ssreflect)

Apr 17, 2010: small improvement obtained by not repeating unification
  twice in auto (-2% in Compcert, -2% in Algebra)

Feb 15, 2010: Global decrease due to unicode inefficiency repaired

Jan 8, 2010: Global increase due to an inefficiency in unicode treatment

Dec 1, 2009 - Dec 19, 2009: Temporary addition of [forall x, P x] hints to
  exact (generally not significative but, e.g., +25% on Subst, +8% on
  ZFC, +5% on AreaMethod)

Oct 19, 2009: Change in modules (CoLoR +35%)

Aug 9, 2009: new files added in AreaMethod

May 21, 2008: New version of CoRN
  (needs +84% more time to compile)

Apr 25-29, 2008: Temporary attempt with delta in eauto (Matthieu)
  (+28% CoRN) 

Apr 17, 2008: improvement probably due to commit 10807 or 10813 (bug
  fixes, control of zeta in rewrite, auto (??))
  (-18% Buchberger, -40% PAutomata, -28% IntMap, -43% CoRN, -13% LinAlg,
  but CatsInZFC -0.5% only, PiCalc stable, PersistentUnionFind -1%)

Mar 11, 2008:
  (+19% PersistentUnionFind wrt Mar 3, +21% Angles, 
   +270% Continuations between 7/3 and 18/4)

Mar 7, 2008:
  (-10% PersistentUnionFind wrt Mar 3)

Feb 20, 2008: temporary 1-day slow down
  (+64% LinAlg)

Feb 14, 2008:
  (-10% PersistentUnionFind, -19% Groups)

Feb 7, 8, 2008: temporary 2-days long slow down
  (+20 LinAlg, +50% BDDs)

Feb 2, 2008: many updates of the module system
  (-13% LinAlg, -50% AMM11262, -5% Goedel, -1% PersistentUnionFind, 
   -42% ExactRealArithmetic, -41% Icharate, -42% Kildall, -74% SquareMatrices)

Jan 1, 2008: merge of TypeClasses branch
  (+8% PersistentUnionFind, +36% LinAlg, +76% Goedel)

Nov 16, 17, 2007:
  (+18% Cantor, +4% LinAlg, +27% IEEE1394 on 2 days)

Nov 8, 2007:
  (+18% Cantor, +16% LinAlg, +55% Continuations, +200% IEEE1394, +170% CTLTCTL,
   +220% SquareMatrices)

Oct 29, V8.1 (+ 3% geometry but CoRN, Godel, Kildall, Stalmark stables)

Between Oct 12 and Oct 27, 2007: inefficiency temporarily introduced in the
  tactic interpreter (from revision 10222 to 10267)
  (+22% CoRN, +10% geometry, ...)

Sep 16, 2007:
  (+16% PersistentUnionFind on 3 days, LinAlg stable,

Sep 4, 2007:
  (+26% PersistentUnionFind, LinAlg stable,

Jun 6, 2007: optimization of the need for type unification in with-bindings
  (-3.5% Stalmark, -6% Kildall)

May 20, 21, 22, 2007: improved inference of with-bindings (including activation
  of unification on types)
  (+4% PICALC, +5% Stalmark, +7% Kildall)

May 11, 2007: added primitive integers (+6% CoLoR, +7% CoRN, +5% FSets, ...)

Between Feb 22 and March 16, 2007: bench temporarily moved on JMN's
  computer (-25% CoRN, -25% Fairisle, ...)

Oct 29 and Oct 30, 2006: abandoned attempt to add polymorphism on definitions
  (+4% in general during these two days)

Oct 17, 2006: improvement in new field [r9248]
  (QArith -3%, geometry: -2%)

Oct 5, 2006: fixing wrong unification of Meta below binders
  (e.g. CatsInZFC: +10%, CoRN: -2.5%, Godel: +4%, LinAlg: +7%,
   DISTRIBUTED_REFERENCE_COUNTING: +10%, CoLoR: +1%)

Sep 26, 2006: new field [r9178-9181]
  (QArith: -16%, geometry: -5%, Float: +6%, BDDS:+5% but no ring in it)

  Sep 12, 2006: Rocq/AREA_METHOD extended (~ 530s)
  Aug 12, 2006: Rocq/AREA_METHOD added (~ 480s)
  May 30, 2006: Nancy/CoLoR added (~ 319s)

May 23, 2006: new, lighter version of polymorphic inductive types
  (CoRN: -27%, back to Mar-24 time)

May 17, 2006: changes in List.v (DISTRIBUTED_REFERENCE_COUNTING: -)

May 5, 2006: improvement in closure (array instead of lists)
  (e.g. CatsInZFC: -10%, CoRN: -3%, 

May 23, 2006: polymorphic inductive types (precise, heavy algorithm)
  (CoRN: +37%)

  Dec 29, 2005: new test and use of -vm in Stalmarck

  Dec 27, 2005: contrib Karatsuba added (~ 30s)

Dec 28, 2005: size decrease
  mainly due to Defined moved to Qed in FSets (reduction from 95M to 7Mo)

Dec 1-14, 2005: benchmarking server down
  between the two dates: Godel: -10%, CoRN: -10%
  probably due to changes around vm (new informative Cast,
  change of equality in named_context_val) 

  Oct 6, 2005: contribs IPC and Tait added (~ 22s and ~ 25s)

Aug 19, 2005: time decrease after application of "Array.length x=0" Xavier's 
  suggestions for optimisation
  (e.g. Nijmegen/QArith: -3%, Nijmegen/CoRN: -7%, Godel: -3%)
 
  Aug 1, 2005: contrib Kildall added (~ 65s)

Jul 26-Aug 2, 2005: bench down

Jul 14-15, 2005: 4 contribs failed including CoRN

Jul 14, 2005: time increase after activation of "closure optimisation"
  (e.g. Nijmegen/QArith: +8%, Nijmegen/CoRN: +3%, Godel: +13%)

  Jul 7, 2005: adding contrib Fermat4

  Jun 17, 2005: contrib Goodstein extended and moved to CantorOrdinals (~ 30s)

  May 19, 2005: contrib Goodstein and prfx (~ 9s) added 

Apr 21, 2005: strange time decrease
  (could it be due to the change of Back and Reset mechanism) 
  (e.g. Nijmegen/CoRN: -2%, Nijmegen/QARITH: -4%, Godel: -11%)

Mar 20, 2005: fixed Logic.with_check bug
  global time decrease (e.g. Nijmegen/CoRN: -3%, Nijmegen/QARITH: -1.5%)

Jan 31-Feb 8, 2005: small instability
  (e.g. CoRN: ~2015s -> ~1999s -> ~2032s, Godel: ~340s -> ~370s)

  Jan 13, 2005: contrib SumOfTwoSquare added (~ 38s)