[Mesa-dev] [PATCH 3/5] i965/vec4: Register spilling should never see registers with size != 1

[Francisco Jerez]

Iago Toral Quiroga <itoral at igalia.com> writes:

> Larger registers should have been moved to scratch (like GRF array access)
> or split to size 1 by the split_virtual_grfs pass.

Not necessarily.  split_virtual_grfs() won't be able to split stuff
which is read or written at once by the same instruction -- E.g. by
send-from-GRF instructions as used for surface messages on e.g.  your
SSBO implementation.  :)

We should probably eventually migrate other messages too like the ones
used for texturing and framebuffer writes to use proper sends from
GRF...

> ---
>  src/mesa/drivers/dri/i965/brw_vec4_reg_allocate.cpp | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/src/mesa/drivers/dri/i965/brw_vec4_reg_allocate.cpp b/src/mesa/drivers/dri/i965/brw_vec4_reg_allocate.cpp
> index cff5406..80ab813 100644
> --- a/src/mesa/drivers/dri/i965/brw_vec4_reg_allocate.cpp
> +++ b/src/mesa/drivers/dri/i965/brw_vec4_reg_allocate.cpp
> @@ -271,7 +271,8 @@ vec4_visitor::evaluate_spill_costs(float *spill_costs, bool *no_spill)
>  
>     for (unsigned i = 0; i < this->alloc.count; i++) {
>        spill_costs[i] = 0.0;
> -      no_spill[i] = alloc.sizes[i] != 1;
> +      no_spill[i] = false;
> +      assert(this->alloc.sizes[i] == 1);
>     }
>  
>     /* Calculate costs for spilling nodes.  Call it a cost of 1 per
> -- 
> 1.9.1
>
> _______________________________________________
> mesa-dev mailing list
> mesa-dev at lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/mesa-dev
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 212 bytes
Desc: not available
URL: <http://lists.freedesktop.org/archives/mesa-dev/attachments/20150724/057477e1/attachment.sig>