[Mesa-dev] [PATCH v2] gles/es3.1: Implement glMemoryBarrierByRegion

[Matt Turner]

On Tue, Aug 4, 2015 at 1:22 AM, Marta Lofstedt
<marta.lofstedt at linux.intel.com> wrote:
> From: Marta Lofstedt <marta.lofstedt at intel.com>
>
> Signed-off-by: Marta Lofstedt <marta.lofstedt at intel.com>
> ---
>  src/mapi/glapi/gen/gl_API.xml           |  4 ++++
>  src/mesa/main/shaderimage.c             | 40 +++++++++++++++++++++++++++++++++
>  src/mesa/main/shaderimage.h             |  3 +++
>  src/mesa/main/tests/dispatch_sanity.cpp |  3 +--
>  4 files changed, 48 insertions(+), 2 deletions(-)
>
> diff --git a/src/mapi/glapi/gen/gl_API.xml b/src/mapi/glapi/gen/gl_API.xml
> index 658efa4..3db4349 100644
> --- a/src/mapi/glapi/gen/gl_API.xml
> +++ b/src/mapi/glapi/gen/gl_API.xml
> @@ -2966,6 +2966,10 @@
>          <param name="height" type="GLsizei"/>
>          <glx rop="191"/>
>      </function>
> +
> +    <function name="MemoryBarrierByRegion" es2="3.1">
> +        <param name="barriers" type="GLbitfield"/>
> +    </function>
>  </category>
>
>  <category name="1.1">
> diff --git a/src/mesa/main/shaderimage.c b/src/mesa/main/shaderimage.c
> index a348cdb..7337f22 100644
> --- a/src/mesa/main/shaderimage.c
> +++ b/src/mesa/main/shaderimage.c
> @@ -653,3 +653,43 @@ _mesa_MemoryBarrier(GLbitfield barriers)
>     if (ctx->Driver.MemoryBarrier)
>        ctx->Driver.MemoryBarrier(ctx, barriers);
>  }
> +
> +void GLAPIENTRY
> +_mesa_MemoryBarrierByRegion(GLbitfield barriers)
> +{
> +   GET_CURRENT_CONTEXT(ctx);
> +
> +   GLbitfield all_allowed_bits = GL_ATOMIC_COUNTER_BARRIER_BIT |
> +                                 GL_FRAMEBUFFER_BARRIER_BIT |
> +                                 GL_SHADER_IMAGE_ACCESS_BARRIER_BIT |
> +                                 GL_SHADER_STORAGE_BARRIER_BIT |
> +                                 GL_TEXTURE_FETCH_BARRIER_BIT |
> +                                 GL_UNIFORM_BARRIER_BIT;
> +
> +   if (ctx->Driver.MemoryBarrier) {
> +      /* From section 7.11.2 of the OpenGL ES 3.1 specification:
> +       *
> +       *    "When barriers is ALL_BARRIER_BITS, shader memory accesses will be
> +       *     synchronized relative to all these barrier bits, but not to other
> +       *     barrier bits specific to MemoryBarrier."
> +       *
> +       * That is, if barriers is the special value GL_ALL_BARRIER_BITS, then all
> +       * barriers allowed by glMemoryBarrierByRegion should be activated."
> +       */
> +      if (barriers == GL_ALL_BARRIER_BITS)
> +         return ctx->Driver.MemoryBarrier(ctx, all_allowed_bits);
> +
> +      /* From section 7.11.2 of the OpenGL ES 3.1 specification:
> +       *
> +       *    "An INVALID_VALUE error is generated if barriers is not the special
> +       *     value ALL_BARRIER_BITS, and has any bits set other than those
> +       *     described above."
> +       */
> +      if ((barriers & ~all_allowed_bits) != 0) {
> +         _mesa_error(ctx, GL_INVALID_VALUE,
> +                     "glMemoryBarrierByRegion(unsupported barrier bit");
> +      }
> +
> +      ctx->Driver.MemoryBarrier(ctx, barriers);
> +   }

Would probably be nice to put an unreachable("not implemented") as an
else case for future implementors.

Reviewed-by: Matt Turner <mattst88 at gmail.com>

Thanks!