[Mesa-dev] [PATCH] st/nir: Disable varying packing when doing transform feedback.

[Timothy Arceri]

On 03/07/18 05:51, Eric Anholt wrote:

> Eric Anholt <eric at anholt.net> writes:
>
>> [ Unknown signature status ]
>> Timothy Arceri <tarceri at itsqueeze.com> writes:
>>
>>> nir_compact_varyings() is meant to skip over varyings used by xfb:
>>>
>>>            /* We can't repack xfb varyings. */
>>>            if (var->data.always_active_io)
>>>               continue;
>>>
>>> Any idea why that isn't working in this case?
>> Looks like GLSL IR has that flag wrong.  points.7 has v_var6,7,8,9
>> transform feedback output, but the IR says:
> [...]
>
> Any feedback on this?  This is my remaining TF issue for V3D.
Hmm. I think this still gets messed up because if packing the non-xfb 
varyings results in freeing up a location then st_nir_assign_var_locations()
will end up assigning a new location for the xfb varyings.

I think your patch to disable for xfb is the easiest way to work around 
this for now. I still hope we might one day have a full NIR GLSL linker 
to replace GLSL IR but my hopes of ever seeing one are slowly fading.

Anyway for this patch:

Reviewed-by: Timothy Arceri <tarceri at itsqueeze.com>