mesa: Add GL/GLSL plumbing for INTEL_fragment_shader_ordering

This extension provides new GLSL built-in function
beginFragmentShaderOrderingIntel() that guarantees
(taking wording of GL_INTEL_fragment_shader_ordering
extension) that any memory transactions issued by
shader invocations from previous primitives mapped to
same xy window coordinates (and same sample when
per-sample shading is active), complete and are visible
to the shader invocation that called
beginFragmentShaderOrderingINTEL().

One advantage of INTEL_fragment_shader_ordering over
ARB_fragment_shader_interlock is that it provides a
function that operates as a memory barrie (instead
of a defining a critcial section) that can be called
under arbitary control flow from any function (in
contrast the begin/end of ARB_fragment_shader_interlock
may only be called once, from main(), under no control
flow.

Signed-off-by: Kevin Rogovin <[email protected]>
Reviewed-by: Plamena Manolova <[email protected]>

1 files changed, 1 insertions, 0 deletions

diff --git a/src/compiler/glsl/glsl_parser_extras.cpp b/src/compiler/glsl/glsl_parser_extras.cpp
index 0a7d0d78b14..21d41224440 100644
--- a/src/compiler/glsl/glsl_parser_extras.cpp
+++ b/src/compiler/glsl/glsl_parser_extras.cpp
@@ -725,6 +725,7 @@ static const _mesa_glsl_extension _mesa_glsl_supported_extensions[] = {
    EXT_AEP(EXT_texture_buffer),
    EXT_AEP(EXT_texture_cube_map_array),
    EXT(INTEL_conservative_rasterization),
+   EXT(INTEL_fragment_shader_ordering),
    EXT(INTEL_shader_atomic_float_minmax),
    EXT(MESA_shader_integer_functions),
    EXT(NV_fragment_shader_interlock),