Motivation

• recent improvements like 12% faster ManyLocalVars bench by using map in resolveUsage #12798
• and 60% speedup of AliasAnalysis with many local variables #12720
• sped AliasAnalysis pass up so much
• that now DataflowAnalysis is the bottleneck!

Why do we need DataflowAnalysis Anyway?

• I performed an experiment to disable DataflowAnalysis
• by commenting out body of runModule and runExpression methods
• runEngineDistribution --run test/Base_Tests continues to pass!
• only runtime-integration-tests/testOnly *Runtime*Test fail
• morever the Base.bindings cache shrinked from 36MB to 26MB!

Only for Interactive Sources

• Looks like DataflowAnalysis is only needed for interactive sources
• e.g. sources processed by runtime-instrument* modules

Goal

• disable DataflowAnalysis for non-interactive sources
• only compute it when IdExecutionInstrument (or co.) needs it
• make sure benchmarks are sped up
  • write new benchmark to mimic interactive use
• make sure caches are smaller