[llvm-commits] [llvm] r151136 - /llvm/trunk/lib/CodeGen/ScheduleDAGInstrs.cpp

[Jakob Stoklund Olesen]

On Feb 21, 2012, at 10:08 PM, Andrew Trick <atrick at apple.com> wrote:

> 
> +  // SSA defs do not have output/anti dependencies.
> +  if (llvm::next(MRI.def_begin(Reg)) == MRI.def_end())
> +    return;
> +

Note that after ProcessImplicitDefs, virtual registers may not have a def, and next(def_begin) is not allowed. (It's fine in this case because the code is explicitly handling a def of Reg).

Should this be a method on MRI, like MRI::hasOneUse?

/jakob