On Wed, 11 Feb 2015, James Bowman wrote: > > > +@table @gcctabopt > > > + > > > +@item -mspace > > > +@opindex mspace > > > +Enable code-size optimizations. > > > +Some of these optimizations incur a minor performance penalty. > > > > We already have -Os, so why is an architecture-specific option for this > > needed? > > Code compiled with -mspace is somewhat slower than code without. > So we typically build *all* code with -Os, with everything > non-critical also compiled -mspace.
The typical way of doing that would be to compile the critical code with -O2, everything else with -Os. It's expected -Os may produce slower code than -O2. -- Joseph S. Myers jos...@codesourcery.com