[Mesa-dev] [PATCH v2 1/3] glsl: add glsl_external_mode() helper

[Timothy Arceri]

On 17/05/18 14:59, Marek Olšák wrote:
> On Thu, May 17, 2018 at 12:50 AM, Timothy Arceri <tarceri at itsqueeze.com 
> <mailto:tarceri at itsqueeze.com>> wrote:
> 
> 
> 
>     On 17/05/18 14:36, Marek Olšák wrote:
> 
>         On Wed, May 16, 2018 at 11:01 PM, Timothy Arceri
>         <tarceri at itsqueeze.com <mailto:tarceri at itsqueeze.com>
>         <mailto:tarceri at itsqueeze.com <mailto:tarceri at itsqueeze.com>>>
>         wrote:
> 
> 
> 
>              On 17/05/18 10:59, Marek Olšák wrote:
> 
>                  On Sat, May 12, 2018 at 12:49 AM, Timothy Arceri
>                  <tarceri at itsqueeze.com <mailto:tarceri at itsqueeze.com>
>         <mailto:tarceri at itsqueeze.com <mailto:tarceri at itsqueeze.com>>
>                  <mailto:tarceri at itsqueeze.com
>         <mailto:tarceri at itsqueeze.com> <mailto:tarceri at itsqueeze.com
>         <mailto:tarceri at itsqueeze.com>>>>
> 
>                  wrote:
> 
>                       This allows us to get the variable mode as
>         specified by the
>                  GLSL
>                       spec. We will use this in the following patch.
>                       ---
>                         src/compiler/glsl/ast_to_hir.cpp | 73
>                  ++++++++++++++++++++++++++++++++
>                         1 file changed, 73 insertions(+)
> 
>                       diff --git a/src/compiler/glsl/ast_to_hir.cpp
>                       b/src/compiler/glsl/ast_to_hir.cpp
>                       index 3bf581571e2..a7a9ac80769 100644
>                       --- a/src/compiler/glsl/ast_to_hir.cpp
>                       +++ b/src/compiler/glsl/ast_to_hir.cpp
>                       @@ -4175,6 +4175,79 @@
>                  apply_type_qualifier_to_variable(const struct
>                       ast_type_qualifier *qual,
>                            apply_image_qualifier_to_variable(qual, var,
>         state, loc);
>                         }
> 
>                       +/**
>                       + * Get the GLSL mode specified in for system
>         values (if any).
>                       + */
>                       +static enum ir_variable_mode
>                       +glsl_external_mode(enum ir_variable_mode
>         internal_mode,
>                       gl_shader_stage stage,
>                       +                   unsigned slot) {
>                       +   if (internal_mode == ir_var_system_value) {
>                       +      switch (slot) {
>                       +      case SYSTEM_VALUE_SUBGROUP_SIZE:
>                       +         return ir_var_uniform;
>                       +      case SYSTEM_VALUE_PRIMITIVE_ID:
>                       +         if (stage == MESA_SHADER_GEOMETRY) {
>                       +            return ir_var_shader_out;
> 
> 
>                  System values are always inputs. This one is
>         gl_PrimitiveIDIn.
> 
>                       +         } else {
>                       +            return ir_var_shader_in;
>                       +         }
>                       +      case SYSTEM_VALUE_TESS_LEVEL_OUTER:
>                       +      case SYSTEM_VALUE_TESS_LEVEL_INNER:
>                       +         if (stage == MESA_SHADER_TESS_CTRL) {
>                       +            return ir_var_shader_out;
> 
> 
>                  System values are always inputs, i.e. TESS_CTRL isn't
>         allowed here.
> 
> 
>              Hmm yeah your right I seem to have confused myself here a bit.
>              However SYSTEM_VALUE_SUBGROUP_SIZE seems to be the odd one
>         out in
>              that its a uniform.
> 
> 
>         Why is it uniform?
> 
> 
>      From ARB_shader_ballot:
> 
> 
>          (Add to the list of built-in uniform variable declaration)
> 
>              uniform uint  gl_SubGroupSizeARB;
> 
> 
> I think it means that gl_SubGroupSizeARB is a compile-time constant. It 
> probably shouldn't be a system value.
> 
> Marek

In that case my original series should be sufficient once this is changed:

https://patchwork.freedesktop.org/series/43049/