Robert Scheck robert@fedoraproject.org writes:
Trying to follow the path on how to get Fedora for ppc64le to a "POWER-Pi", I had to learn that glibc developers seem to treat IBM POWER9 strictly equal to ABI rules rather handling the different features more fine granulated. My understanding here might be imprecise or wrong, this is what I understood and I'm no expert at this topic.
There are indeed a couple of bad assumptions in glibc code that go beyond what Florian mentioned about the ELFv2 ABI. These include fixed cache line size and assuming that VSX is available POWER ISA 2.06 or later.
Even though we can't change the ELFv2 ABI, I've been (slowly) working to remove these assumptions and make it easier to use an ELFv2 glibc build on processors that do not implement VSX.
If you find any other issues, please let me know. I'll be glad to fix them.
The IBM Power ISA Version 3.1 [10] specifies on page 8 compliancy subsets, where the Linux Compliancy Subset (LCS) is explained on page 10 ff.
Notice that SIMD is not a Linux Optional feature in this page. ;-)