http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58269
--- Comment #19 from Iain Sandoe <iains at gcc dot gnu.org> --- (In reply to Mike Stump from comment #18) > On Sep 6, 2013, at 8:43 AM, howarth at nitro dot med.uc.edu > <gcc-bugzi...@gcc.gnu.org> wrote: > > * i386.c (ix86_hard_regno_mode_ok): AVX modes are valid only when > > > > AVX is enabled. > > llvm has: > > // The first 8 512-bit vector arguments are passed in ZMM registers. > CCIfNotVarArg<CCIfType<[v16i32, v8i64, v16f32, v8f64], > CCIfSubtarget<"hasAVX512()", > CCAssignToReg<[ZMM0, ZMM1, ZMM2, ZMM3, ZMM4, ZMM5, ZMM6, > ZMM7]>>>>, > > just after the sse registers… conceptually, I wonder if gcc is missing that. On the basis that clang (Darwin11, Darwin12) defines the ABI - we should see about this. Presumably, this should be disabled for OS versions where gcc-4.2/gcc-4.0 are the "system compiler". As of now, the documentation does not refer to this - the web page still points to the older psABI. Is there an official update to the System V psABI covering these regs?