http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50186
--- Comment #8 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-08-25 12:10:26 UTC --- And 476 CPU according to rs6000-cpus.def should support that: RS6000_CPU ("476", PROCESSOR_PPC476, POWERPC_BASE_MASK | MASK_SOFT_FLOAT | MASK_PPC_GFXOPT | MASK_MFCRF | MASK_POPCNTB | MASK_FPRND | MASK_CMPB | MASK_MULHW | MASK_DLMZB) so the bug is probably on your assembler side.