elizabethandrews wrote: > > I requested some minor changes. > > Can we document the `.ifunc` symbols as a deprecated feature? With this > > change, they will never be referenced except by code compiled by older > > compiler versions. Maybe plan to deprecate them a year from now? > > How/where do I document this? > > > It looks like there is a related issue in which multiple ifunc symbols are > > emitted for the `cpu_dispatch` attribute. See > > https://godbolt.org/z/71vr8ceza. The relevant symbols emitted are listed > > below. Note that both `_Z12cpu_specificv` and `_Z12cpu_specificv.ifunc` are > > "i" symbols with the same address. The caller in this case calls the > > `.ifunc` symbol (just as for `target_clones` prior to this change). It > > would be nice if we can fix this issue at the same time and likewise > > deprecate the `.ifunc` symbol for `cpu_dispatch`/`cpu_specific`. > > ``` > > 00000000000024c0 i _Z12cpu_specificv > > 0000000000002480 T _Z12cpu_specificv.A > > 0000000000002490 T _Z12cpu_specificv.M > > 00000000000024c0 i _Z12cpu_specificv.ifunc > > 00000000000024c0 W _Z12cpu_specificv.resolver > > ``` > > > > > > > > > > > > > > > > > > > > > > > > I think the only time a symbol with a `.ifunc` suffix is actually needed is > > when the `target` attribute is used in an overloading context (since in > > that situation, the `target(default)` definition gets the non-suffixed name. > > The symbols correspond to the ifunc and it's alias. Mangling rules seem to > vary between different MV attributes. For example - for `target` attribute, > the default versions do not include a `.default` suffix. I do not know what > the mangling requirements for `cpu_dispatch` are off the top of my head. I do > not think we should change it to match `target_clones` attribute without > confirming this is the correct behavior for this attribute.
@tahonermann as discussed offline, I documented the deprecation in attribute documentation. I wasn't 100% certain of what to say, so please feel free to wordsmith! As also discussed, I will make changes to `cpu_dispatch` in a follow-up PR. https://github.com/llvm/llvm-project/pull/71706 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
