[Mesa-dev] [PATCH 02/10] glsl: keep track of ssbo variable being accessed, add access params

[Iago Toral]

On Mon, 2016-01-18 at 00:51 -0500, Ilia Mirkin wrote:
> Currently any access params (coherent/volatile/restrict) are being lost
> when lowering to the ssbo load/store intrinsics. Keep track of the
> variable being used, and bake its access params in as the last arg of
> the load/store intrinsics.

This patch is
Reviewed-by: Iago Toral Quiroga <itoral at igalia.com>

It does not add the NIR implementation so if someone wants to use this
with NIR we will have to add the glsl_to_nir code to read this last
parameter and update the ssbo intrinsics in NIR to include it as well.

Iago

> Signed-off-by: Ilia Mirkin <imirkin at alum.mit.edu>
> ---
>  src/glsl/lower_ubo_reference.cpp | 23 +++++++++++++++++++++++
>  src/glsl/nir/shader_enums.h      | 10 ++++++++++
>  2 files changed, 33 insertions(+)
> 
> diff --git a/src/glsl/lower_ubo_reference.cpp b/src/glsl/lower_ubo_reference.cpp
> index a172054..2fa50c7 100644
> --- a/src/glsl/lower_ubo_reference.cpp
> +++ b/src/glsl/lower_ubo_reference.cpp
> @@ -104,6 +104,7 @@ public:
>  
>     struct gl_shader *shader;
>     struct gl_uniform_buffer_variable *ubo_var;
> +   ir_variable *variable;
>     ir_rvalue *uniform_block;
>     bool progress;
>  };
> @@ -317,6 +318,7 @@ lower_ubo_reference_visitor::handle_rvalue(ir_rvalue **rvalue)
>     this->buffer_access_type =
>        var->is_in_shader_storage_block() ?
>        ssbo_load_access : ubo_load_access;
> +   this->variable = var;
>  
>     /* Compute the offset to the start if the dereference as well as other
>      * information we need to configure the write
> @@ -370,6 +372,14 @@ shader_storage_buffer_object(const _mesa_glsl_parse_state *state)
>     return state->ARB_shader_storage_buffer_object_enable;
>  }
>  
> +static uint32_t
> +ssbo_access_params(const ir_variable *var)
> +{
> +   return (var->data.image_coherent ? ACCESS_COHERENT : 0) |
> +          (var->data.image_restrict ? ACCESS_RESTRICT : 0) |
> +          (var->data.image_volatile ? ACCESS_VOLATILE : 0);
> +}

I was meaning to send a patch to rename the image_* fields after landing
ssbos and then I forgot about that... I'll write a patch after you land
this, hopefully I won't forget it this time...

>  ir_call *
>  lower_ubo_reference_visitor::ssbo_store(void *mem_ctx,
>                                          ir_rvalue *deref,
> @@ -394,6 +404,10 @@ lower_ubo_reference_visitor::ssbo_store(void *mem_ctx,
>        ir_variable(glsl_type::uint_type, "write_mask" , ir_var_function_in);
>     sig_params.push_tail(writemask_ref);
>  
> +   ir_variable *access_ref = new(mem_ctx)
> +      ir_variable(glsl_type::uint_type, "access" , ir_var_function_in);
> +   sig_params.push_tail(access_ref);
> +
>     ir_function_signature *sig = new(mem_ctx)
>        ir_function_signature(glsl_type::void_type, shader_storage_buffer_object);
>     assert(sig);
> @@ -408,6 +422,7 @@ lower_ubo_reference_visitor::ssbo_store(void *mem_ctx,
>     call_params.push_tail(offset->clone(mem_ctx, NULL));
>     call_params.push_tail(deref->clone(mem_ctx, NULL));
>     call_params.push_tail(new(mem_ctx) ir_constant(write_mask));
> +   call_params.push_tail(new(mem_ctx) ir_constant(ssbo_access_params(variable)));
>     return new(mem_ctx) ir_call(sig, NULL, &call_params);
>  }
>  
> @@ -426,6 +441,10 @@ lower_ubo_reference_visitor::ssbo_load(void *mem_ctx,
>        ir_variable(glsl_type::uint_type, "offset_ref" , ir_var_function_in);
>     sig_params.push_tail(offset_ref);
>  
> +   ir_variable *access_ref = new(mem_ctx)
> +      ir_variable(glsl_type::uint_type, "access" , ir_var_function_in);
> +   sig_params.push_tail(access_ref);
> +
>     ir_function_signature *sig =
>        new(mem_ctx) ir_function_signature(type, shader_storage_buffer_object);
>     assert(sig);
> @@ -444,6 +463,7 @@ lower_ubo_reference_visitor::ssbo_load(void *mem_ctx,
>     exec_list call_params;
>     call_params.push_tail(this->uniform_block->clone(mem_ctx, NULL));
>     call_params.push_tail(offset->clone(mem_ctx, NULL));
> +   call_params.push_tail(new(mem_ctx) ir_constant(ssbo_access_params(variable)));
>  
>     return new(mem_ctx) ir_call(sig, deref_result, &call_params);
>  }
> @@ -499,6 +519,7 @@ lower_ubo_reference_visitor::write_to_memory(void *mem_ctx,
>     unsigned packing = var->get_interface_type()->interface_packing;
>  
>     this->buffer_access_type = ssbo_store_access;
> +   this->variable = var;
>  
>     /* Compute the offset to the start if the dereference as well as other
>      * information we need to configure the write
> @@ -678,6 +699,7 @@ lower_ubo_reference_visitor::process_ssbo_unsized_array_length(ir_rvalue **rvalu
>     int unsized_array_stride = calculate_unsized_array_stride(deref, packing);
>  
>     this->buffer_access_type = ssbo_unsized_array_length_access;
> +   this->variable = var;
>  
>     /* Compute the offset to the start if the dereference as well as other
>      * information we need to calculate the length.
> @@ -910,6 +932,7 @@ lower_ubo_reference_visitor::lower_ssbo_atomic_intrinsic(ir_call *ir)
>     unsigned packing = var->get_interface_type()->interface_packing;
>  
>     this->buffer_access_type = ssbo_atomic_access;
> +   this->variable = var;
>  
>     setup_for_load_or_store(mem_ctx, var, deref,
>                             &offset, &const_offset,
> diff --git a/src/glsl/nir/shader_enums.h b/src/glsl/nir/shader_enums.h
> index c747464..19610c9 100644
> --- a/src/glsl/nir/shader_enums.h
> +++ b/src/glsl/nir/shader_enums.h
> @@ -535,6 +535,16 @@ enum gl_frag_depth_layout
>     FRAG_DEPTH_LAYOUT_UNCHANGED
>  };
>  
> +/**
> + * \brief Buffer access qualifiers
> + */
> +enum gl_buffer_access_qualifier
> +{
> +   ACCESS_COHERENT = 1,
> +   ACCESS_RESTRICT = 2,
> +   ACCESS_VOLATILE = 4,
> +};
> +
>  #ifdef __cplusplus
>  } /* extern "C" */
>  #endif