On Tue, Nov 3, 2015 at 8:40 PM, Ilia Mirkin <<a href="mailto:imirkin@alum.mit.edu">imirkin@alum.mit.edu</a>> wrote: > Ian, any comment on this? > > On Fri, Sep 25, 2015 at 1:32 PM, Ilia Mirkin <<a href="mailto:imirkin@alum.mit.edu">imirkin@alum.mit.edu</a>> wrote: >> Hi Ian (and other spec experts), >> >> The ARB_ssbo spec mentions the following: >> >> OpenGL 4.0 (either core or compatibility profile) is required. >> >> ... >> >> Additionally, the shading language provides the memoryBarrier() function >> to control the relative order of memory accesses within individual shader >> invocations and provides various memory qualifiers controlling how the >> memory corresponding to individual variables is accessed. >> >> However the memoryBarrier() function only becomes available in GLSL >> 4.20 [along with the glMemoryBarrier() function that the spec also >> refers to] or with ARB_shader_image_load_store. >> >> Is the implication that such functionality should be auto-exposed in >> image-less drivers that support ssbo? Or that this functionality >> should just not exist unless images are supported? That looks like a spec bug. If the spec says "the shading language provides the memoryBarrier", it should provide it. Marek