On Mon, Jan 20, 2014 at 5:22 PM, Jan Hubicka <hubi...@ucw.cz> wrote: >> >> Yes. Say, this could be surrounded by some try/catch, if we do it the first >> way, a would be still considered live across the EH path to whatever catches >> it. >> >> The EH optimizations involving cleanups with only clobbers in them are that >> if at the end of the cleanup after only CLOBBER stmts you would rethrow the >> exception >> externally, then the clobber isn't needed and the whole cleanup can be >> removed. And, if it rethrows somewhere internally, we can move the clobber >> stmts to the landing pad of wherever it would be caught. > > OK, I still do not see how ehclanup1 can then safely remove them pre-inline > given that the whole function body can be inlined into another containing the > outer EH region.
That's true. > If this is valid, why we can not just eliminate EH in those > outer clobber try..finally as part of ehlowering earlier? Probably we'd miss too many inlining cases from early inlining and the ehcleanup1 time is just a heuristic that works good enough for us? Jakub? Micha? Thanks, Richard. > Honza >> >> Jakub
