On Thu, 24 Sep 2009, Joseph S. Myers wrote: > On Thu, 24 Sep 2009, Richard Guenther wrote: > > > We discussed about features we don't like (PCH and -combine). PCH > > is used but has the issue that improper use is not diagnosed and PCH > > seems to be unmaintained. We agreed on deprecating -combine for 4.5 > > though. > > Can we map -combine to use LTO transparently in 4.6 (deprecate the > implementation, keep the interface)?
We thought about that, but the issue with LTO is that you need to use the gcc driver at link time and pass -flto there. But yes, in principle you could continue to handle -combine in the driver by doing the link step to build an object file. Supporting it on cc1 is probably not going to work though. Is -combine widely used? IIRC it has a lot of known issues and is basically unmaintained. Maybe if we deprecate -combine for 4.5 we'll get feedback if it is used. Richard.
