cluster acceleration structure optix 6431 (#7028)

* Add cluster geometry intrinsics for ray tracing

- Added GetClusterID() method to HitObject class
- Added CandidateClusterID() and CommittedClusterID() methods to
RayQuery class
- Added SPV_NV_cluster_acceleration_structure extension support
- Added GL_NV_cluster_acceleration_structure extension support
- Added test files for RayQuery and HitObject cluster methods

Fixes #6431

* OpRayQueryGetIntersectionClusterIdNV - unrecognized spirv
Disabling spirv backend for SPV_NV_cluster_acceleration_structure

hlsl.meta.slang(18674): error 29100: unrecognized spirv opcode:
OpRayQueryGetIntersectionClusterIdNV
                result:$$int = OpRayQueryGetIntersectionClusterIdNV
&this $iCandidateOrCommitted;
                ^~~~~~
hlsl.meta.slang(18670): error 30019: expected an expression of type
'int', got 'void'
            return spirv_asm
                   ^~~~~~~~~
ninja: build stopped: subcommand failed.

* 6431 - Fix spirv opcode

* Remove tests

* Add relevant tests

* Review - Simplify tests

4 files changed, 143 insertions, 1 deletions

diff --git a/source/slang/glsl.meta.slang b/source/slang/glsl.meta.slang
index 00ad88add..05cef836c 100644
--- a/source/slang/glsl.meta.slang
+++ b/source/slang/glsl.meta.slang
@@ -4893,6 +4893,35 @@ public property uint gl_HitKindEXT
     }
 }
 
+public property int gl_ClusterIDNV
+{
+    [require(glsl_spirv, raytracing_anyhit_closesthit)]
+    get
+    {
+        setupExtForRayTracingBuiltIn();
+        __target_switch
+        {
+        case glsl:
+        {
+            __requireTargetExtension("GL_NV_cluster_acceleration_structure");
+            __intrinsic_asm "(gl_ClusterIDNV)";
+        }
+        case spirv:
+        {
+            return spirv_asm
+            {
+                OpCapability RayTracingClusterAccelerationStructureNV;
+                OpExtension "SPV_NV_cluster_acceleration_structure";
+                result:$$int = OpLoad builtin(ClusterIDNV:int);
+            };
+        }
+        }
+    }
+}
+// Constant to indicate that a cluster acceleration structure was not hit.
+// Corresponds to VK_GEOMETRY_INSTANCE_CLUSTER_ID_NONE_NV in Vulkan
+public static const int gl_ClusterIDNoneNV = -1;
+
 public property mat4x3 gl_ObjectToWorldEXT 
 {
     [require(glsl_spirv, raytracing_anyhit_closesthit_intersection)]
diff --git a/source/slang/hlsl.meta.slang b/source/slang/hlsl.meta.slang
index 99eba0a42..34423d4f3 100644
--- a/source/slang/hlsl.meta.slang
+++ b/source/slang/hlsl.meta.slang
@@ -17889,6 +17889,26 @@ float RayCurrentTime()
     }
 }
 
+/// @category raytracing
+[__requiresNVAPI]
+__glsl_extension(GL_NV_cluster_acceleration_structure)
+__glsl_extension(GL_EXT_ray_tracing)
+[NonUniformReturn]
+[require(cuda_glsl_hlsl_spirv, raytracing_anyhit_closesthit)]
+int GetClusterID()
+{
+    __target_switch
+    {
+    case hlsl:  __intrinsic_asm "NvRtGetClusterID";
+    case glsl:  __intrinsic_asm "(gl_ClusterIDNV)";
+    case cuda: __intrinsic_asm "optixGetClusterId";
+    case spirv:
+        return spirv_asm
+        {
+            result:$$int = OpLoad builtin(ClusterIDNV:int);
+        };
+    }
+}
 // Note: The provisional DXR spec included these unadorned
 // `ObjectToWorld()` and `WorldToObject()` functions, so
 // we will forward them to the new names as a convience
@@ -18683,6 +18703,31 @@ struct RayQuery <let rayFlagsGeneric : RAY_FLAG = RAY_FLAG_NONE>
         }
     }
 
+    /// Gets the cluster ID of the candidate hit.
+    /// @return Cluster ID for the candidate hit
+    /// @remarks HLSL/GLSL/SPIRV
+    [__requiresNVAPI]
+    __glsl_extension(GL_NV_cluster_acceleration_structure)
+    __glsl_extension(GL_EXT_ray_query)
+    [__NoSideEffect]
+    [require(glsl_hlsl_spirv, rayquery)]
+    int CandidateClusterID()
+    {
+        __target_switch
+        {
+        case hlsl: __intrinsic_asm "NvRtGetCandidateClusterID";
+        case glsl: __intrinsic_asm "rayQueryGetIntersectionClusterIdNV($0, false)";
+        case spirv:
+            uint iCandidateOrCommitted = 0;
+            return spirv_asm
+            {
+                OpExtension "SPV_NV_cluster_acceleration_structure";
+                OpCapability RayTracingClusterAccelerationStructureNV;
+                result:$$int = OpRayQueryGetClusterIdNV &this $iCandidateOrCommitted;
+            };
+        }
+    }
+
     /// Gets the custom index of the instance containing the committed hit.
     /// @return User-provided instance identifier
     /// @remarks GLSL/SPIRV only
@@ -18698,7 +18743,32 @@ struct RayQuery <let rayFlagsGeneric : RAY_FLAG = RAY_FLAG_NONE>
             uint iCandidateOrCommitted = 1;
             return spirv_asm
             {
-                result:$$int = OpRayQueryGetIntersectionInstanceCustomIndexKHR &this $iCandidateOrCommitted;
+                result:$$int = OpRayQueryGetClusterIdNV &this $iCandidateOrCommitted;
+            };
+        }
+    }
+
+    /// Gets the cluster ID of the committed hit.
+    /// @return Cluster ID for the committed hit
+    /// @remarks HLSL/GLSL/SPIRV
+    [__requiresNVAPI]
+    __glsl_extension(GL_NV_cluster_acceleration_structure)
+    __glsl_extension(GL_EXT_ray_query)
+    [__NoSideEffect]
+    [require(glsl_hlsl_spirv, rayquery)]
+    int CommittedClusterID()
+    {
+        __target_switch
+        {
+        case hlsl: __intrinsic_asm "NvRtGetCommittedClusterID";
+        case glsl: __intrinsic_asm "rayQueryGetIntersectionClusterIdNV($0, true)";
+        case spirv:
+            uint iCandidateOrCommitted = 1; // 1 for committed
+            return spirv_asm
+            {
+                OpExtension "SPV_NV_cluster_acceleration_structure";
+                OpCapability RayTracingClusterAccelerationStructureNV;
+                result:$$int = OpRayQueryGetClusterIdNV &this $iCandidateOrCommitted;
             };
         }
     }
@@ -20354,6 +20424,29 @@ struct HitObject
         }
     }
 
+    /// Returns the cluster ID of the current hit. Valid if the hit object represents a hit.
+    [__requiresNVAPI]
+    __glsl_extension(GL_NV_cluster_acceleration_structure)
+    __glsl_extension(GL_EXT_ray_tracing)
+    [ForceInline]
+    [require(cuda_glsl_hlsl_spirv, ser_raygen_closesthit_miss)]
+    int GetClusterID()
+    {
+        __target_switch
+        {
+        case hlsl: __intrinsic_asm ".GetClusterID";
+        case glsl: __intrinsic_asm "hitObjectGetClusterIdNV($0)";
+        case cuda: __intrinsic_asm "optixHitObjectGetClusterId";
+        case spirv:
+            return spirv_asm
+            {
+                OpExtension "SPV_NV_cluster_acceleration_structure";
+                OpCapability RayTracingClusterAccelerationStructureNV;
+                result:$$int = OpHitObjectGetClusterIdNV &this;
+            };
+        }
+    }
+
     [__requiresNVAPI]
     __glsl_extension(GL_EXT_ray_tracing)
     [ForceInline]
diff --git a/source/slang/slang-capabilities.capdef b/source/slang/slang-capabilities.capdef
index b50519a72..fafcb214f 100644
--- a/source/slang/slang-capabilities.capdef
+++ b/source/slang/slang-capabilities.capdef
@@ -539,6 +539,10 @@ def SPV_NV_ray_tracing_motion_blur : _spirv_1_0;
 /// [EXT]
 def SPV_NV_shader_invocation_reorder : _spirv_1_5 + SPV_KHR_ray_tracing;
 
+/// Represents the SPIR-V extension for cluster acceleration structure.
+/// [EXT]
+def SPV_NV_cluster_acceleration_structure : _spirv_1_0;
+
 /// Represents the SPIR-V extension for shader image footprint.
 /// [EXT]
 def SPV_NV_shader_image_footprint : _spirv_1_0;
@@ -689,6 +693,10 @@ def spvRayQueryPositionFetchKHR : SPV_KHR_ray_tracing_position_fetch + spvRayQue
 /// [EXT]
 def spvShaderInvocationReorderNV : SPV_NV_shader_invocation_reorder;
 
+/// Represents the SPIR-V capability for cluster acceleration structure.
+/// [EXT]
+def spvRayTracingClusterAccelerationStructureNV : SPV_NV_cluster_acceleration_structure;
+
 /// Represents the SPIR-V capability for shader clock.
 /// [EXT]
 def spvShaderClockKHR : SPV_KHR_shader_clock;
@@ -809,6 +817,7 @@ def _GL_NV_shader_atomic_fp16_vector : _GL_NV_gpu_shader5;
 def _GL_NV_shader_invocation_reorder : _GLSL_460;
 def _GL_NV_shader_subgroup_partitioned : _GLSL_140;
 def _GL_NV_shader_texture_footprint : _GLSL_450;
+def _GL_NV_cluster_acceleration_structure : _GLSL_460;
 
 // GLSL extension and SPV extension associations.
 
@@ -1044,6 +1053,10 @@ alias GL_NV_shader_subgroup_partitioned = _GL_NV_shader_subgroup_partitioned | s
 /// [EXT]
 alias GL_NV_shader_texture_footprint = _GL_NV_shader_texture_footprint | spvImageFootprintNV;
 
+/// Represents the GL_NV_cluster_acceleration_structure extension.
+/// [EXT]
+alias GL_NV_cluster_acceleration_structure = _GL_NV_cluster_acceleration_structure | spvRayTracingClusterAccelerationStructureNV;
+
 // Define feature names not reliant on shader stages
 
 /// NVAPI capability for HLSL
diff --git a/source/slang/slang-emit-spirv.cpp b/source/slang/slang-emit-spirv.cpp
index bd9b23b2d..096e7d8bc 100644
--- a/source/slang/slang-emit-spirv.cpp
+++ b/source/slang/slang-emit-spirv.cpp
@@ -1433,6 +1433,13 @@ struct SPIRVEmitContext : public SourceEmitterBase, public SPIRVEmitSharedContex
         return ensureExtensionDeclaration(name);
     }
 
+    // Ensure cluster acceleration structure extensions and capabilities are declared
+    void requireRayTracingClusterAccelerationStructure()
+    {
+        requireSPIRVCapability(SpvCapabilityRayTracingClusterAccelerationStructureNV);
+        ensureExtensionDeclaration(UnownedStringSlice("SPV_NV_cluster_acceleration_structure"));
+    }
+
     bool hasExtensionDeclaration(const UnownedStringSlice& name)
     {
         return m_extensionInsts.containsKey(name);