[Mesa-dev] [PATCH v3] mesa: Implement glMemoryBarrierByRegion

[Marta Lofstedt]

From: Marta Lofstedt <marta.lofstedt at intel.com>

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

Signed-off-by: Marta Lofstedt <marta.lofstedt at intel.com>
---
 src/mapi/glapi/gen/GL4x.xml             |  6 +++++
 src/mesa/main/shaderimage.c             | 40 +++++++++++++++++++++++++++++++++
 src/mesa/main/shaderimage.h             |  3 +++
 src/mesa/main/tests/dispatch_sanity.cpp |  9 ++++++--
 4 files changed, 56 insertions(+), 2 deletions(-)

diff --git a/src/mapi/glapi/gen/GL4x.xml b/src/mapi/glapi/gen/GL4x.xml
index 94ddfb7..dee5027 100644
--- a/src/mapi/glapi/gen/GL4x.xml
+++ b/src/mapi/glapi/gen/GL4x.xml
@@ -44,4 +44,10 @@
   <enum name="DEPTH_STENCIL_TEXTURE_MODE"              value="0x90EA"/>
 </category>
 
+<category name="4.5">
+  <function name="MemoryBarrierByRegion" es2="3.1">
+    <param name="barriers" type="GLbitfield"/>
+  </function>
+</category>
+
 </OpenGLAPI>
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);
+   }
+}
diff --git a/src/mesa/main/shaderimage.h b/src/mesa/main/shaderimage.h
index 33d8a1e..d08ece8 100644
--- a/src/mesa/main/shaderimage.h
+++ b/src/mesa/main/shaderimage.h
@@ -68,6 +68,9 @@ _mesa_BindImageTextures(GLuint first, GLsizei count, const GLuint *textures);
 void GLAPIENTRY
 _mesa_MemoryBarrier(GLbitfield barriers);
 
+void GLAPIENTRY
+_mesa_MemoryBarrierByRegion(GLbitfield barriers);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/src/mesa/main/tests/dispatch_sanity.cpp b/src/mesa/main/tests/dispatch_sanity.cpp
index af89d2c..59107eb 100644
--- a/src/mesa/main/tests/dispatch_sanity.cpp
+++ b/src/mesa/main/tests/dispatch_sanity.cpp
@@ -851,6 +851,9 @@ const struct function common_desktop_functions_possible[] = {
 // { "glTextureStorage2DMultisampleEXT", 43, -1 },      // XXX: Add to xml
 // { "glTextureStorage3DMultisampleEXT", 43, -1 },      // XXX: Add to xml
 
+/* GL 4.5 */
+   { "glMemoryBarrierByRegion", 45, -1 },
+
    /* GL_ARB_internalformat_query */
    { "glGetInternalformativ", 30, -1 },
 
@@ -1739,6 +1742,9 @@ const struct function gl_core_functions_possible[] = {
 // { "glTextureStorage2DMultisampleEXT", 43, -1 },      // XXX: Add to xml
 // { "glTextureStorage3DMultisampleEXT", 43, -1 },      // XXX: Add to xml
 
+/* GL 4.5 */
+   { "glMemoryBarrierByRegion", 45, -1 },
+
    /* GL_ARB_direct_state_access */
    { "glCreateTransformFeedbacks", 45, -1 },
    { "glTransformFeedbackBufferBase", 45, -1 },
@@ -2461,8 +2467,7 @@ const struct function gles31_functions_possible[] = {
    { "glGetBooleani_v", 31, -1 },
    { "glMemoryBarrier", 31, -1 },
 
-   // FINISHME: This function has not been implemented yet.
-   // { "glMemoryBarrierByRegion", 31, -1 },
+   { "glMemoryBarrierByRegion", 31, -1 },
 
    { "glTexStorage2DMultisample", 31, -1 },
    { "glGetMultisamplefv", 31, -1 },
-- 
1.9.1