https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93526
Jakub Jelinek <jakub at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |jakub at gcc dot gnu.org --- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> --- Why do you think this is a bug? c modifier behaves differently depending on whether the operand is CONSTANT_ADDRESS_P or not, and if it is not, it falls through to the target specific hook (ix86_output_operand in this case) and that for c/C as documented requires the operand to be a comparison from which it extracts condition codes. E.g. 0x80000000UL or 0xffff80000000UL is neither of those, therefore you get a failure.