[Mesa-dev] [PATCH 3/3] mesa: optimize _mesa_attr_zero_aliases_vertex()

[Brian Paul]

On 08/21/2017 01:09 PM, Samuel Pitoiset wrote:
>
>
> On 08/21/2017 08:56 PM, Brian Paul wrote:
>> After the context is initialized, the API and context flags won't
>> change.  So, we can compute whether vertex attribute 0 aliases
>> vertex position just once.
>>
>> This should make the glVertexAttrib*() functions a little quicker.
>>
>> No Piglit regressions with llvmpipe.
>> ---
>>   src/mesa/main/context.c | 17 +++++++++++++++++
>>   src/mesa/main/mtypes.h  |  3 +++
>>   src/mesa/main/varray.h  | 14 ++------------
>>   3 files changed, 22 insertions(+), 12 deletions(-)
>>
>> diff --git a/src/mesa/main/context.c b/src/mesa/main/context.c
>> index b4b7b6e..842edf0 100644
>> --- a/src/mesa/main/context.c
>> +++ b/src/mesa/main/context.c
>> @@ -1607,6 +1607,23 @@ handle_first_current(struct gl_context *ctx)
>>         }
>>      }
>> +   /* Determine if generic vertex attribute 0 alias the conventional
>> +    * glVertex position.
>> +    */
>> +   {
>> +      const bool is_forward_compatible_context =
>> +         ctx->Const.ContextFlags &
>> GL_CONTEXT_FLAG_FORWARD_COMPATIBLE_BIT;
>> +
>> +      /* In OpenGL 3.1 attribute 0 becomes non-magic, just like in
>> OpenGL ES
>> +       * 2.0.  Note that we cannot just check for API_OPENGL_COMPAT
>> here because
>> +       * that will erroneously allow this usage in a 3.0
>> forward-compatible
>> +       * context too.
>> +       */
>> +      ctx->AttribZeroAliasesVertex = (ctx->API == API_OPENGLES
>> +                                      || (ctx->API == API_OPENGL_COMPAT
>> +                                          &&
>> !is_forward_compatible_context));
>> +   }
>> +
>>      /* We can use this to help debug user's problems.  Tell them to set
>>       * the MESA_INFO env variable before running their app.  Then the
>>       * first time each context is made current we'll print some useful
>> diff --git a/src/mesa/main/mtypes.h b/src/mesa/main/mtypes.h
>> index 49eb7d5..a8fa045 100644
>> --- a/src/mesa/main/mtypes.h
>> +++ b/src/mesa/main/mtypes.h
>> @@ -4972,6 +4972,9 @@ struct gl_context
>>      GLboolean RasterDiscard;  /**< GL_RASTERIZER_DISCARD */
>>      GLboolean IntelConservativeRasterization; /**<
>> GL_INTEL_CONSERVATIVE_RASTERIZATION */
>> +   /** Does glVertexAttrib(0) alias glVertex()? */
>> +   bool AttribZeroAliasesVertex;
>
> Usually, internal variables are prefixed with '_', no?
>
> With that fixed, series is:
>
> Reviewed-by: Samuel Pitoiset <samuel.pitoiset at gmail.com>

Will do. Thanks.

-Brian

>
>> +
>>      /**
>>       * \name Hooks for module contexts.
>>       *
>> diff --git a/src/mesa/main/varray.h b/src/mesa/main/varray.h
>> index 730f7cf..ba74ae6 100644
>> --- a/src/mesa/main/varray.h
>> +++ b/src/mesa/main/varray.h
>> @@ -73,19 +73,9 @@ _mesa_update_client_array(struct gl_context *ctx,
>>   }
>>   static inline bool
>> -_mesa_attr_zero_aliases_vertex(struct gl_context *ctx)
>> +_mesa_attr_zero_aliases_vertex(const struct gl_context *ctx)
>>   {
>> -   const bool is_forward_compatible_context =
>> -      ctx->Const.ContextFlags & GL_CONTEXT_FLAG_FORWARD_COMPATIBLE_BIT;
>> -
>> -   /* In OpenGL 3.1 attribute 0 becomes non-magic, just like in
>> OpenGL ES
>> -    * 2.0.  Note that we cannot just check for API_OPENGL_COMPAT here
>> because
>> -    * that will erroneously allow this usage in a 3.0 forward-compatible
>> -    * context too.
>> -    */
>> -   return (ctx->API == API_OPENGLES
>> -           || (ctx->API == API_OPENGL_COMPAT
>> -               && !is_forward_compatible_context));
>> +   return ctx->AttribZeroAliasesVertex;
>>   }
>>   extern void
>>