https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111366
--- Comment #6 from Jan Wassenberg <jan.wassenberg at gmail dot com> --- Thinking about this more, the LTO means more opportunity for inlining and thus for the compiler to hit the legit "don't want to inline POWER9 into POWER8" error. Interestingly this does not happen on x86 - even if we have -march=haswell, #pragma target -mssse3 is not a problem. Perhaps POWER9 vs POWER8 has a larger/wider impact on codegen than Haswell vs SSE. I suppose we will have to work around this on the library level: if we detect any POWER9 flag, then do not attempt to also generate POWER8 codepaths.
