define: DUK_USE_EXEC_FUN_LOCAL
introduced: 1.4.0
default: false
tags:
  - performance
  - execution
description: >
  Use a local variable "fun" pointing to the current function in the bytecode
  dispatch loop instead of looking up the current function through "thr" every
  time it is needed.  On x64 performance is slightly better without a "fun"
  local; on x86 performance is slightly better with one.

  You should only tweak this if you're really interested in performance, and
  should then do proper testing to see which value works better.