Optimizing existing large codebase Measire Modemise Mem threads Specificity of the exercise Dealing with large code base (Mloc) o most of them unknown to you and(usually)not supported by anyone Dealing with old code using old fashion coding style (e.g.FORTRAN like) modified n times,grew organically o Target latest hardware many cores hyperthreading superscalar 。vectorization 4/57 S.Ponce-CERNOptimizing existing large codebase 4 / 57 S. Ponce - CERN Measure Modernize Mem threads low level c/c Specificity of the exercise Dealing with large code base (Mloc) most of them unknown to you and (usually) not supported by anyone Dealing with old code using old fashion coding style (e.g. FORTRAN like) modified n times, grew organically Target latest hardware many cores hyperthreading / superscalar vectorization