-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 On Fri, 2020-07-24 at 14:32 -0600, Jeff Law wrote: > On Fri, 2020-07-24 at 22:30 +0200, Igor Raits wrote: > > On Fri, 2020-07-24 at 14:27 -0600, Jeff Law wrote: > > > On Fri, 2020-07-24 at 22:24 +0200, Igor Raits wrote: > > > > On Fri, 2020-07-24 at 13:29 -0600, Jeff Law wrote: > > > > > On Fri, 2020-07-24 at 19:12 +0000, Artem Tim wrote: > > > > > > Hi. In rare cases building packages with LTO producing > > > > > > binaries > > > > > > or > > > > > > libraries which have bigger size then if they have built > > > > > > without > > > > > > LTO. For example 'kitty' package: > > > > > > > > > > > > * with LTO: > > > > > > - koji task > > > > > > https://koji.fedoraproject.org/koji/taskinfo?taskID=47762998 > > > > > > 1.79 MB glfw-wayland.so > > > > > > 1.99 MB glfw-x11.so > > > > > > 4.78 MB fast_data_types.so > > > > > > 8.56 MB total > > > > > > > > > > > > * no LTO > > > > > > - koji > > > > > > https://koji.fedoraproject.org/koji/taskinfo?taskID=47769854 > > > > > > 1.65 MB glfw-wayland.so > > > > > > 1.84 MB glfw-x11.so > > > > > > 4.51 MB fast_data_types.so > > > > > > 8.00 MB total > > > > > > > > > > > > Difference is 7%. What we should do in such case? Should we > > > > > > disable > > > > > > LTO for such packages? Or there is still could be gains > > > > > > from > > > > > > faster > > > > > > code execution speed? > > > > > I'd tend to leave LTO on, but it's totally your call. > > > > > Without > > > > > looking at the > > > > > binaries, sources and compiler dumps I'd hazard a guess > > > > > you're > > > > > getting a lot of > > > > > cross module inlining, but very little identical code > > > > > folding. > > > > > THe > > > > > former tends > > > > > to make things bigger, but faster. The latter tends to > > > > > shrink > > > > > code > > > > > with little > > > > > impact on runtime performance. > > > > > > > > From what I see in this case, -ffat-lto-objects generates code > > > > that > > > > is > > > > bigger than without -flto. -flto alone generates smaller code > > > > than > > > > without -flto. > > > The fat-lto-objects bits are not used during an LTO link. They > > > exist > > > solely to > > > cover the case where there's a .o/.a that ends up installed. > > > > Well, I tell what I see :) > > > > Compiling kitty with settings below produces this big > > /usr/lib64/kitty/kitty/fast_data_types.so: > > > > * Without any LTO-related flags: 4.52 MB > > * With -flto: 4.30 MB > > * With -flto -ffat-lto-objects: 4.79 MB > > > > Well, I did not run compilation multiple times but don't think it > > will > > change much. > That's quite bizarre. I'll put it on the list of things to > investigate. Hi Jeff, Any news about this issue? > jeff > - -- Igor Raits <ignatenkobrain@xxxxxxxxxxxxxxxxx> -----BEGIN PGP SIGNATURE----- iQIzBAEBCgAdFiEEcwgJ58gsbV5f5dMcEV1auJxcHh4FAl9Li60ACgkQEV1auJxc Hh4q4A/6AyqFOE64rYb6gdhdlqJWKZovmucbeXMnpq6wD0zUqrpvaUyyAaSjGQ6D tLs+7RC8rFqErfPDUsnSll90+HiHqHRp1O6UOLjRQ8EwbSVZGQ0e0l5NfrktRy8i mjMG1r7KrKbuRQi3/4//lg8PQroVvXLqNIuwSpLYiDYA3loJAra0+pdP2mSdiWpk zAn8uAx5wOLNmWKqv+OS6SU3oiJXAOezBgDSoF70fgxAep7qgv6J+wjLrtkl2U1G 3atZ2r7+pfvI5UiFp9/0CXT0ZW9SQRoXMza0OURZpvUIk21f0nYjQgXv4gEWttf/ 7hOO4n+tg3xqurgb91j7WW9VNEiMbACYTidv/jxhAqOwBj6jeozh5e0YrmsRZ3Oa ZN74SWXl9k2Omh8By3EaNappHCLO9Oxr0DTkt+hc2JNTtmc9m5SPYnl4nd+N80wd iqv1Cg9wG46cL+Ofnz+L03F7rzsXN0ywwoKOZMGwkPsGrmOFcxko4iJ4j7tzUCiz K0iJFqeYoh6oPRGomZ1+KZP+mlKGaV9GZ0FhdIhCOB0MV0Yshk+4TdW5OQ5sYsby YLL12yN/WKCRsm16XH1bT8hu8Qu56bued0HOn9PrYDqz4txa2+d6QdOLUFTATiOY QfWO+31o236UkWSjxc+Wc34KHox5vr+ueNrnDUaKtwOc7jpqvJ0= =zrRd -----END PGP SIGNATURE----- _______________________________________________ devel mailing list -- devel@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe send an email to devel-leave@xxxxxxxxxxxxxxxxxxxxxxx Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/devel@xxxxxxxxxxxxxxxxxxxxxxx
