On Wed, Jun 4, 2008 at 12:50, Kenneth Zadeck <[EMAIL PROTECTED]> wrote:
> While i agree that some form of lto needs to support monster apps, that > should not inhibit us from supporting transformations or models of > compilation that are only practical with 100k line programs. Of course not. That was never the intent. Supporting small/medium sized applications is inherent in the WHOPR design. If we can't handle that efficiently, then we have a design/implementation bug. While we (Google) are mostly interested in summary-based IPA for very large applications, we do not want the design to negate other uses of LTO. WHOPR is designed to support the whole spectrum, from small/medium sized applications where the whole program fits in memory, to extremely large applications where memory/computing requirements are prohibitive for a single machine. In practice, the full distributed model that WHOPR offers will not need to be triggered for small applications, only very large ones. Ideally, we should be able to hide all that behind 'gcc -flto' and let the compiler decide how to operate. The natural restriction is that passes of type SMALL_IPA will not be able to run when the full distributed version is being used. Again, this is something I expect the compiler to be able to figure out for itself. Diego.
