GCC optimization options

Dear Sir or Madam,
     First, I want to find GCC optimization options that can greatly improve the performance, and I want to know the specific meaning of this option.
Besides,I found that ‘-ftree-sra’ 、'-finline-functions-called-once',may have an impact on performance improvement.
Therefore, I want to write test cases in depth to verify whether these options can optimize test results.
How to achieve this? How can the specific meaning of these options be clearly reflected through test cases?

    I am looking forward to your favorable replay.