[Mesa-dev] [PATCH 2/2] st/glsl_to_tgsi: fix block copies of arrays of structs

[Timothy Arceri]

On Mon, 2016-10-17 at 19:25 +0200, Nicolai Hähnle wrote:
> From: Nicolai Hähnle <nicolai.haehnle at amd.com>
> 
> Use a full writemask in this case. This is relevant e.g. when a
> function
> has an inout argument which is an array of structs.
> ---
>  src/mesa/state_tracker/st_glsl_to_tgsi.cpp | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
> b/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
> index 1662f7f..b91ebaf 100644
> --- a/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
> +++ b/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
> @@ -2964,24 +2964,26 @@ glsl_to_tgsi_visitor::visit(ir_assignment
> *ir)
>  
>           if (variable->data.location == FRAG_RESULT_DEPTH)
>              l.writemask = WRITEMASK_Z;
>           else {
>              assert(variable->data.location == FRAG_RESULT_STENCIL);
>              l.writemask = WRITEMASK_Y;
>           }
>        } else if (ir->write_mask == 0) {
>           assert(!ir->lhs->type->is_scalar() && !ir->lhs->type-
> >is_vector());
>  
> -         if (ir->lhs->type->is_array() || ir->lhs->type-
> >is_matrix()) {
> -            unsigned num_elements = ir->lhs->type->without_array()-
> >vector_elements;
> +         unsigned num_elements = ir->lhs->type->without_array()-
> >vector_elements;
> +
> +         if (num_elements) {
>              l.writemask = u_bit_consecutive(0, num_elements);
>           } else {
> +            // The type is a struct or an array of (array of)
> structs.


C++ style comment in Mesa :(


>              l.writemask = WRITEMASK_XYZW;
>           }
>        } else {
>           l.writemask = ir->write_mask;
>        }
>  
>        for (int i = 0; i < 4; i++) {
>           if (l.writemask & (1 << i)) {
>              first_enabled_chan = GET_SWZ(r.swizzle, i);
>              break;