[Intel-gfx] Register "linking"

[Olivier Galibert]

  Hi guys,

I'm playing with my gm45, and trying to understand the inter-shader
register allocation and referencing aspects.  From what I see, the vs
and clipper follow the brw_vue_map to know where data is.  The
fragment shader, though, does its own input register allocation in the
urb_setup array.  How is the link done between the two?  I've been
unable to find it...

Best,

  OG.