root/ext/opcache/Optimizer/

[..]
  1. block_pass.c
  2. compact_literals.c
  3. nop_removal.c
  4. optimize_func_calls.c
  5. optimize_temp_vars_5.c
  6. pass1_5.c
  7. pass2.c
  8. pass3.c
  9. zend_optimizer.c
  10. zend_optimizer.h
  11. zend_optimizer_internal.h
[..]