Found this while looking at C source code of ruby:
http://en.wikipedia.org/wiki/Peephole_optimization
There are bunch of compile optimizations that can be enabled/disabled by using the method:
RubyVM::InstructionSequence.compile_option = {
trace_instruction: false,
tailcall_optimization: true,
peephole_optimization: true,
# ..etc..
}
Default options:
{ :inline_const_cache => true, :peephole_optimization => true, :tailcall_optimization => false, :specialized_instruction => true, :operands_unification => true, :instructions_unification => false, :stack_caching => false, :trace_instruction => true, :debug_level => 0 }