question on optimization

[Diego Novillo]

On 10/26/07, Jim Marshall <jim.marshall@wbemsolutions.com> wrote:

> gcc <options> module1.c module2.c ... moduleN.c?

With the current version of GCC, there is no difference.  However, if
you *do* compile all the .c files with a single command and use
-combine then the compiler will treat all the .c files as a single one
and the IPA optimizations will work on all the files at once.  This
option is currently supported on C only.

For future versions of GCC we are working on link-time optimization
features which will be more powerful than -combine (See
http://gcc.gnu.org/wiki/LinkTimeOptimization for some details).  This
is not likely to be in GCC for at least a couple of releases, though.