On Thu, 20 Feb 2020, GT wrote: > What more needs to be done other than documenting the GLIBC and GCC > versions for which 'b' and 'c' vector versions are available? It is how > x86_64 explained the differences between Examples 1 and 2 at > https://sourceware.org/glibc/wiki/libmvec
This is about ISA variants in the ABI. <https://sourceware.org/glibc/wiki/libmvec?action=AttachFile&do=view&target=VectorABI.txt> says "Compiler implementations must not generate calls to version of other ISAs unless some non-standard pragma or clause is used to declare those other versions are available.". The same needs to apply to the POWER ABI - any pragma or attribute declaring vector functions to be available must have a fixed set of ISA variants the ABI says it declares to be available, with any ISA variants added in future needing a new pragma or attribute to declare them to be available, to avoid GCC 20 misinterpreting glibc 2.32 headers as implying function variants are available for ISAs that didn't exist when those glibc 2.32 headers were written. -- Joseph S. Myers jos...@codesourcery.com
