I m compiling my C app using GCC 4 3 Instead of manually selecting the optimization flags I m using -march native which in theory should add all optimization flags applicable to the hardware I m compiling on But how can I check which flags is it actually using

How to see which flags -march=native will activate?

You can use the -Q --help=target options:

gcc -march=native -Q --help=target ...

The -v option may also be of use.

You can see the documentation on the --help option here.

~ Answered on 2011-03-29 09:24:27