Similar to nir_lower_alu_width(), the callback can return the
desired number of components for a phi, or 0 for no lowering.
The previous behavior of nir_lower_phis_to_scalar() with lower_all=true
can be elicited via nir_lower_all_phis_to_scalar() while the previous
behavior with lower_all=false now corresponds to nir_lower_phis_to_scalar()
with NULL callback.
Reviewed-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Reviewed-by: Mel Henning <mhenning@darkrefraction.com>
Reviewed-by: Georg Lehmann <dadschoorse@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/35783>
This is a cleanup.
Old gs LDS layout: [es outputs][gs outputs][scratch]
Old nogs LDS layout: [xfb/cull][scratch]
New gs LDS layout: [es outputs][scratch|gs outputs]
New nogs LDS layout: [scratch|xfb/cull]
The LDS scratch is moved to the beginning of the preceding buffer in LDS,
while the addresses in that LDS buffer are offset by the scratch size.
It effectively merges the LDS scratch with the preceding buffer in LDS.
Thanks to that, we no longer need the ngg_scratch ABI and the offset
in a user SGPR.
The lowering passes now return the LDS scratch size, which is used
by the drivers to determine the final LDS size.
The ngg_lds_layout SGPR is now unused without GS in RADV.
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/35352>
