This is beautification prep work since vgt will add even more special
cases. With these macros it's much easier to see what's going on
really.
Signed-off-by: NYu Zhang <yu.c.zhang@linux.intel.com>
[danvet: #undef the temporary macros after the function again. And
write a commit message.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>