On 11/13/2018 03:30 AM, ? ? wrote: > When I use gcc -S -O2 test.c , the main function part in the output .s file is empty. > But my last try with gcc -S test.c works normally. The C code was correctly compiled to asembly file. Plz tell me how to use the optimization options. We don't know. What was the test? What did it do? -- Andrew Haley Java Platform Lead Engineer Red Hat UK Ltd. <https://www.redhat.com> EAC8 43EB D3EF DB98 CC77 2FAD A5CD 6035 332F A671