http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58268
Richard Biener <rguenth at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |RESOLVED Resolution|--- |INVALID Summary|umm registers not used for |ymm registers not used for |-march=bdver1 |-march=bdver1 --- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> --- I think it's a deliberate tuning choice for this architecture which I think enables -mprefer-avx128 by default: config/i386/x86-tune.def:DEF_TUNE (X86_TUNE_AVX128_OPTIMAL, "avx128_optimal", m_BDVER | m_BTVER2)