mesa: Implement glMemoryBarrierByRegion

The function glMemoryBarrierByRegion is part of OpenGL ES 3.1
and OpenGL 4.5 core and compatibility profiles.

Signed-off-by: Marta Lofstedt <[email protected]>
Reviewed-by: Tapani Pälli <[email protected]>

1 files changed, 40 insertions, 0 deletions

diff --git a/src/mesa/main/shaderimage.c b/src/mesa/main/shaderimage.c
index a348cdb0405..7337f2255c4 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);
+   }
+}