Axel Naumann

Nada FTE  LLVM + cling would take 4 years  when done, move to next hot-spot in ROOT Axel Naumann ROOT Team Meeting2

Lotsa FTEs: 1. Cling Spread benefits throughout ROOT:  overhaul UpdateListOfClasses() etc  remove rootmap (part of dictionary)  use parser in TFormula, THtml,… Major:  JIT compile serialization for given type: switch optimized away  re-think TSelector: predict requested branches by looking at code Axel Naumann ROOT Team Meeting3

Lotsa FTEs: 2. Dynamic Builder Move from just-in-case to on-demand compilation  can revolutionize software distribution / build chain / OS  dump concept of shared libraries  instead: collection of provided and missing symbols + prescription for building Axel Naumann ROOT Team Meeting4

Dynamic Builder  major concept change for dynamic loader's symbol requests: only at call time (sort of like now with fPIC) can provoke compilation  a bit like Java's ClassLoader  enables Rene's BOOT: source doesn't need to be local Axel Naumann ROOT Team Meeting5

Dynamic Builder: Experiments  build time reduced: only syntax and dependency checks  load time reduced: cached symbol resolution (aka compilation)  memory usage reduced: only code that's actually run Axel Naumann ROOT Team Meeting6

Dynamic Builder: Planning  >= 3 years  >= 2 people – needs computer scientist!  could be independent of CINT / ROOT, but we would benefit and we have the tools!  later: predictive JIT, use multicore network calls, e.g. for PROOF Axel Naumann ROOT Team Meeting7

The Group Thing vs. "CINT" G4 can benefit from  interpreter interface  serialization  JIT compile navigator for defined geometry, no more "switch (nextsurface) {}" find more if / switch… that can be reduced at runtime! Axel Naumann ROOT Team Meeting8