This is intended to be called before nir_lower_io() so that we
can do some linking optimisations with the results. It can also
be used with drivers that don't use nir_lower_io() at all such
as RADV.
v2: pass mode mask rather than first and last stage integer.
Reviewed-by: Eric Anholt <eric@anholt.net>
If the source is an indirect register, there is ralloc'd data. Copying
with a direct assignment will copy the pointer, but the data will still
belong to the old instruction's memory context. Since we're lowering
and throwing away instructions, that could free the data by mistake.
Instead, use nir_src_copy, which properly handles this.
This is admittedly not a common case, so I think the bug is real,
but unlikely to be hit.
Cc: mesa-stable@lists.freedesktop.org
Reviewed-by: Matt Turner <mattst88@gmail.com>
vc4 wants to have per-scalar IO load/stores so that dead code elimination
can happen on a more granular basis, which it has been doing in the
backend using a multiplication by 4 of the intrinsic's driver_location.
We can represent it properly in the NIR using the first_component field,
though.
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
