On 7/23/19 2:49 AM, Martin Liška wrote: > On 7/22/19 4:31 PM, Jeff Law wrote: >> On 7/22/19 8:25 AM, Martin Liška wrote: >>> On 7/17/19 8:10 PM, Jeff Law wrote: >>>> On 7/17/19 11:29 AM, Andi Kleen wrote: >>>>> Romain Geissler <romain.geiss...@amadeus.com> writes: >>>>>> >>>>>> I have no idea of the LTO format and if indeed it can easily be updated >>>>>> in a backward compatible way. But I would say it would be nice if it >>>>>> could, and would allow adoption for projects spread on many teams >>>>>> depending on each others and unable to re-build everything at each >>>>>> toolchain update. >>>>> >>>>> Right now any change to an compiler option breaks the LTO format >>>>> in subtle ways. In fact even the minor changes that are currently >>>>> done are not frequent enough to catch all such cases. >>>>> >>>>> So it's unlikely to really work. >>>> Right and stable LTO bytecode really isn't on the radar at this time. >>>> >>>> IMHO it's more important right now to start pushing LTO into the >>>> mainstream for the binaries shipped by the vendors (and stripping the >>>> LTO bits out of any static libraries/.o's shipped by the vendors). >>>> >>>> >>>> SuSE's announcement today is quite ironic. >>> >>> Why and what is ironic about it? >> Sorry, you'd have to have internal context -- we'd been discussing it >> within the Red Hat team for Fedora 32 the previous day. One of the >> questions that came up was whether or not any other major distributor >> was shipping with LTO enabled :-) > > According to what I know, OpenMandriva should be using LTO: > https://www.openmandriva.org/en/news/article/openmandriva-lx-4-0-rc-released > but the package building machinery is closed, so I can't confirm that. > > One another example is Gentoo: > https://github.com/InBetweenNames/gentooLTO > but it's up to users preferences.> > So that I consider openSUSE Tumbleweed as a first one :P As do I.
Jeff
