We need to declare global register usage (outside usual abi restrictions)
on sparc64 with

  .register %g2,#scratch
  .register %g3,#scratch

(and we do this in the kernel quite a lot).

However, this seems to create "empty" undefined symbols:

# nm /netbsd |fgrep " U " 
                 U 
                 U 

Using #ignore instead of #scratch makes those Us go away.

This is a binutils bug, isn't it?

Martin