Fasten pix hit matcher 80 x

[fcouderc]

Backport 81X code to make pixel seeding much faster...
remove Cxx flag compare last 80X PR
Needed for HLT urgently

[cmsbuild]

A new Pull Request was created by @fcouderc for CMSSW_8_0_X.

It involves the following packages:

RecoEgamma/EgammaElectronAlgos

@cmsbuild, @cvuosalo, @slava77, @davidlange6 can you please review it and eventually sign? Thanks.
@Sam-Harper, @rafaellopesdesa, @lgray this is something you requested to watch as well.
@slava77, @Degano, @smuzaffar you are the release manager for this.

cms-bot commands are list here #13028

[slava77]

@cmsbuild please test

[cmsbuild]

The tests are being triggered in jenkins.
https://cmssdt.cern.ch/jenkins/job/ib-any-integration/13376/console

[cmsbuild]

+1
Tested at: c6d0a00
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-14779/13376/summary.html

[cmsbuild]

Comparison is ready
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-14779/13376/summary.html

[fwyzard]

@slava77 , @cvuosalo , @davidlange6 , could you approve this for 8.0.x as well ?
We will need an 8.0.10-patch2 with it for online deployment.

[slava77]

+1

for #14779 c6d0a00

• changes in RecoEgamma/EgammaElectronAlgos/interface/PixelHitMatcher.h from 81X Speed seeding for HLT #13819 backported to 80X. THe goal is to reduce CPU use; no changes are expected in the outputs.
• jenkins tests pass and comparisons with baseline show no differences
• comparison in 134.902 (doubleEG from 2015D) shows that most of the speedup visible in Speed seeding for HLT #13819 in hltEgammaElectronPixelSeeds, hltEgammaElectronPixelSeedsUnseeded is present in this PR as well.

[cmsbuild]

This pull request is fully signed and it will be integrated in one of the next CMSSW_8_0_X IBs (tests are also fine). This pull request requires discussion in the ORP meeting before it's merged. @slava77, @davidlange6, @Degano, @smuzaffar

[davidlange6]

+1