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/ir.h b/src/compiler/glsl/ir.h
index d05d1998a50..f478b29a6b5 100644
--- a/src/compiler/glsl/ir.h
+++ b/src/compiler/glsl/ir.h
@@ -1122,6 +1122,7 @@ enum ir_intrinsic_id {
    ir_intrinsic_memory_barrier_shared,
    ir_intrinsic_begin_invocation_interlock,
    ir_intrinsic_end_invocation_interlock,
+   ir_intrinsic_begin_fragment_shader_ordering,
 
    ir_intrinsic_vote_all,
    ir_intrinsic_vote_any,