Performance analysis for V8-0 branch
------------------------------------

Oct 29, 2006: polymorphism on definitions (+ 4%)

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%, 
   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 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%, 

  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)