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

[Ilia Mirkin]

On Tue, Dec 29, 2015 at 4:45 PM, Jason Ekstrand <jason at jlekstrand.net> wrote:
>
>
> On Mon, Dec 28, 2015 at 11:06 AM, Ilia Mirkin <imirkin at alum.mit.edu> 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.
>>
>> Signed-off-by: Ilia Mirkin <imirkin at alum.mit.edu>
>> ---
>>
>> This is RFC because there are still no users, but I'm working on that.
>> Don't
>> want to be going in the completely wrong direction though...
>>
>>  src/glsl/lower_ubo_reference.cpp | 22 ++++++++++++++++++++++
>>  1 file changed, 22 insertions(+)
>>
>> diff --git a/src/glsl/lower_ubo_reference.cpp
>> b/src/glsl/lower_ubo_reference.cpp
>> index a172054..5b3f523 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 +372,13 @@ 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 << 0) |
>> +          (var->data.image_volatile << 1) |
>> +          (var->data.image_restrict << 2);
>
>
> Do 0, 1, and 2 have some special meaning I should know about?  I suggest we
> add an enum to shader_enums.h.

Do you mean a struct with a bitfield? That'd work for me.

  -ilia