There are two compiler options for optimizations: -O and
-O2. These options enable optimization at both translation
(from COBOL to C) and compilation (C to assembly) levels.
Currently, there is no difference between -O and -O2 at
the translation level. The only thing which is done is inlining some
run-time functions, by enabling the option -fruntime-inlining
(see Compiler Options).
The option -O or -O2 is passed to the C compiler as it
is and used for C level optimization.