https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108240
--- Comment #4 from Segher Boessenkool <segher at gcc dot gnu.org> --- (In reply to Kewen Lin from comment #3) > With the culprit commit r13-4894, we always implicitly enable powerpc64 for > both explicit and implicit 64 bit, it's the same as before for the explicit > 64 bit case, but for the implicit 64 bit case, there is no chance for the > used cpu to unset powerpc64 (like this case). To keep it consistent with the > previous, the fix can be to only enable powerpc64 implicitly for explicit 64 > bit, while let it be for implicit 64 bit. No? If the user says to use a CPU without 64-bit instructions, while the user also says we require 64-bit insns (via -m64), we should just error. Not hide the problem (and cause many more problems!) We used to do that: f951: Error: ‘-m64’ requires a PowerPC64 cpu We can do such a check again, just in a bit different spot probably.