On Wed, Jun 17, 2015 at 5:20 PM, Jordan Justen <jordan.l.jus...@intel.com> wrote: > I wanted to question whether this was required, based on this text > from the extension spec: > > "The ability to write to buffer objects creates the potential for > multiple independent shader invocations to read and write the same > underlying memory. The same issue exists with the > ARB_shader_image_load_store extension provided in OpenGL 4.2, which > can write to texture objects and buffers. In both cases, the > specification makes few guarantees related to the relative order of > memory reads and writes performed by the shader invocations." > > But I'm not sure if we can reconcile CSE with 'memoryBarrier' and > 'barrier'. curro, any thoughts from image load/store?
I think the point is that if you have two reads of the same location, you can't combine them into a single load since in the intervening time another shader invocation might have written to that location...? The question about the semantics of memory-barriers is a good one though. _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
