On 03/02/2015 08:04 PM, Andres Tiraboschi wrote: >> On 03/02/2015 07:56 PM, Andres Tiraboschi wrote: >>> But passing those flags I listed above, why the compiler is not doing >>> those optimizations? >> >> Because you have said -O0. -O0 means no optimization. >> >> With -O0, all those other optimization options are ignored. > > forget -O0, compiling this way I have exactly the same problem: > g++ -finline-functions -finline-functions-called-once > -finline-small-functions -ftree-coalesce-inlined-vars -Wall -Wextra > -pedantic -std=c++11 -Winline main.cpp > > (is the same but without -O0) -O0 is the default. If you want optimization, you have to turn it on.