https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114732
--- Comment #4 from Segher Boessenkool <segher at gcc dot gnu.org> --- (In reply to Segher Boessenkool from comment #3) > -- Bit 0 is all-true, bit 2 is all-false, like in the vcmp* insns. (And bits 1 and 3 are set to zeroes for those insns. So it is all one-hot there as well. But the meaning is different.)