Support the GLSL/SPIR-V Built-in variable DeviceIndex

docs/command-line-slangc-reference.md

@@ -1133,6 +1133,7 @@ A capability describes an optional feature that a target may or may not support.
 * `SPV_KHR_quad_control` : enables the SPV_KHR_quad_control extension 
 * `SPV_KHR_fragment_shader_barycentric` : enables the SPV_KHR_fragment_shader_barycentric extension 
 * `SPV_KHR_non_semantic_info` : enables the SPV_KHR_non_semantic_info extension 
+* `SPV_KHR_device_group` : enables the SPV_KHR_device_group extension 
 * `SPV_KHR_ray_tracing` : enables the SPV_KHR_ray_tracing extension 
 * `SPV_KHR_ray_query` : enables the SPV_KHR_ray_query extension 
 * `SPV_KHR_ray_tracing_position_fetch` : enables the SPV_KHR_ray_tracing_position_fetch extension 
@@ -1152,6 +1153,7 @@ A capability describes an optional feature that a target may or may not support.
 * `SPV_KHR_cooperative_matrix` : enables the SPV_KHR_cooperative_matrix extension 
 * `SPV_NV_tensor_addressing` : enables the SPV_NV_tensor_addressing extension 
 * `SPV_NV_cooperative_matrix2` : enables the SPV_NV_cooperative_matrix2 extension 
+* `spvDeviceGroup` 
 * `spvAtomicFloat32AddEXT` 
 * `spvAtomicFloat16AddEXT` 
 * `spvAtomicFloat64AddEXT` 
@@ -1254,6 +1256,7 @@ A capability describes an optional feature that a target may or may not support.
 * `GL_EXT_demote_to_helper_invocation` : enables the GL_EXT_demote_to_helper_invocation extension 
 * `GL_EXT_maximal_reconvergence` : enables the GL_EXT_maximal_reconvergence extension 
 * `GL_EXT_shader_quad_control` : enables the GL_EXT_shader_quad_control extension 
+* `GL_EXT_device_group` : enables the GL_EXT_device_group extension 
 * `GL_EXT_fragment_shader_barycentric` : enables the GL_EXT_fragment_shader_barycentric extension 
 * `GL_EXT_mesh_shader` : enables the GL_EXT_mesh_shader extension 
 * `GL_EXT_nonuniform_qualifier` : enables the GL_EXT_nonuniform_qualifier extension 

docs/user-guide/a2-01-spirv-target-specific.md

@@ -66,6 +66,7 @@ The system-value semantics are translated to the following SPIR-V code.
 | `SV_DispatchThreadID`         | `BuiltIn GlobalInvocationId`      |
 | `SV_DomainLocation`           | `BuiltIn TessCoord`               |
 | `SV_DrawIndex`<sup>*</sup>    | `Builtin DrawIndex`               |
+| `SV_DeviceIndex`              | `Builtin DeviceIndex`             |
 | `SV_GSInstanceID`             | `BuiltIn InvocationId`            |
 | `SV_GroupID`                  | `BuiltIn WorkgroupId`             |
 | `SV_GroupIndex`               | `BuiltIn LocalInvocationIndex`    |

docs/user-guide/a3-02-reference-capability-atoms.md

@@ -403,6 +403,9 @@ Extensions
 `SPV_KHR_non_semantic_info`
 > Represents the SPIR-V extension for non-semantic information.
 
+`SPV_KHR_device_group`
+> Represents the SPIR-V extension for device-group information.
+
 `SPV_KHR_ray_tracing`
 > Represents the SPIR-V extension for ray tracing.
 
@@ -465,6 +468,9 @@ Extensions
 `SPV_NV_cooperative_matrix2`
 > Represents the SPIR-V extension for SPV_NV_cooperative_matrix2.
 
+`spvDeviceGroup`
+> Represents the SPIR-V capability for DeviceGroup.
+
 `spvAtomicFloat32AddEXT`
 > Represents the SPIR-V capability for atomic float 32 add operations.
 
@@ -636,6 +642,9 @@ Extensions
 `GL_EXT_shader_quad_control`
 > Represents the GL_EXT_shader_quad_control extension.
 
+`GL_EXT_device_group`
+> Represents the GL_EXT_device_group extension.
+
 `GL_EXT_fragment_shader_barycentric`
 > Represents the GL_EXT_fragment_shader_barycentric extension.
 

source/slang/glsl.meta.slang

@@ -127,8 +127,19 @@ public in uvec3 gl_WorkGroupID : SV_GroupID;
 public in uint gl_LocalInvocationIndex : SV_GroupIndex;
 public in uvec3 gl_LocalInvocationID : SV_GroupThreadID;
 
-public property uint3 gl_NumWorkGroups {
+internal in int _gl_DeviceIndex : SV_DeviceIndex;
+public property int gl_DeviceIndex
+{
+    [__unsafeForceInlineEarly]
+    [require(glsl_spirv, GL_EXT_device_group)]
+    get
+    {
+        return _gl_DeviceIndex;
+    }
+}
 
+public property uint3 gl_NumWorkGroups
+{
     [require(glsl_spirv, GLSL_430_SPIRV_1_0_compute)]
     get 
     {

source/slang/slang-capabilities.capdef

@@ -511,6 +511,10 @@ def SPV_KHR_fragment_shader_barycentric : _spirv_1_0;
 /// [EXT]
 def SPV_KHR_non_semantic_info : _spirv_1_0;
 
+/// Represents the SPIR-V extension for device-group information.
+/// [EXT]
+def SPV_KHR_device_group : _spirv_1_0;
+
 /// Represents the SPIR-V extension for ray tracing.
 /// [EXT]
 def SPV_KHR_ray_tracing : _spirv_1_4;
@@ -596,6 +600,10 @@ def SPV_NV_cooperative_matrix2 : SPV_NV_tensor_addressing + SPV_KHR_cooperative_
 
 // SPIRV Capabilities.
 
+/// Represents the SPIR-V capability for DeviceGroup.
+/// [EXT]
+def spvDeviceGroup : SPV_KHR_device_group;
+
 /// Represents the SPIR-V capability for atomic float 32 add operations.
 /// [EXT]
 def spvAtomicFloat32AddEXT : SPV_EXT_shader_atomic_float_add;
@@ -840,6 +848,7 @@ def _GL_EXT_texture_query_lod : glsl;
 def _GL_EXT_texture_shadow_lod : _GLSL_130;
 def _GL_EXT_maximal_reconvergence : _GLSL_140;
 def _GL_EXT_shader_quad_control : _GLSL_140;
+def _GL_EXT_device_group : _GLSL_140;
 
 def _GL_ARB_derivative_control : _GLSL_400;
 def _GL_ARB_fragment_shader_interlock : _GLSL_450;
@@ -905,6 +914,10 @@ alias GL_EXT_maximal_reconvergence = _GL_EXT_maximal_reconvergence | spvMaximalR
 /// [EXT]
 alias GL_EXT_shader_quad_control = _GL_EXT_shader_quad_control | spvQuadControlKHR;
 
+/// Represents the GL_EXT_device_group extension.
+/// [EXT]
+alias GL_EXT_device_group = _GL_EXT_device_group | spvDeviceGroup;
+
 /// Represents the GL_EXT_fragment_shader_barycentric extension.
 /// [EXT]
 alias GL_EXT_fragment_shader_barycentric = _GL_EXT_fragment_shader_barycentric | spvFragmentBarycentricKHR;

source/slang/slang-emit-spirv.cpp

@@ -6023,6 +6023,12 @@ struct SPIRVEmitContext : public SourceEmitterBase, public SPIRVEmitSharedContex
                     requireSPIRVCapability(SpvCapabilityDrawParameters);
                     return getBuiltinGlobalVar(inst->getFullType(), SpvBuiltInDrawIndex, inst);
                 }
+                else if (semanticName == "sv_deviceindex")
+                {
+                    ensureExtensionDeclaration(UnownedStringSlice("SPV_KHR_device_group"));
+                    requireSPIRVCapability(SpvCapabilityDeviceGroup);
+                    return getBuiltinGlobalVar(inst->getFullType(), SpvBuiltInDeviceIndex, inst);
+                }
                 else if (semanticName == "sv_primitiveid")
                 {
                     auto entryPoints = m_referencingEntryPoints.tryGetValue(inst);

source/slang/slang-ir-glsl-legalize.cpp

@@ -666,6 +666,12 @@ GLSLSystemValueInfo* getGLSLSystemValueInfo(
         name = "gl_DrawID";
         requiredType = builder->getBasicType(BaseType::Int);
     }
+    else if (semanticName == "sv_deviceindex")
+    {
+        name = "gl_DeviceIndex";
+        requiredType = builder->getBasicType(BaseType::Int);
+        context->requireGLSLExtension(UnownedStringSlice::fromLiteral("GL_EXT_device_group"));
+    }
     else if (semanticName == "sv_primitiveid")
     {
         // uint in hlsl, int in glsl

source/slang/slang-ir-legalize-varying-params.h

@@ -59,6 +59,7 @@ void depointerizeInputParams(IRFunc* entryPoint);
     M(PointCoord, SV_PointCoord)                         \
     M(PrimitiveID, SV_PrimitiveID)                       \
     M(DrawIndex, SV_DrawIndex)                           \
+    M(DeviceIndex, SV_DeviceIndex)                       \
     M(RenderTargetArrayIndex, SV_RenderTargetArrayIndex) \
     M(SampleIndex, SV_SampleIndex)                       \
     M(StencilRef, SV_StencilRef)                         \

source/slang/slang-language-server-completion.cpp

@@ -121,6 +121,7 @@ static const char* hlslSemanticNames[] = {
     "SV_PointCoord",
     "SV_PrimitiveID",
     "SV_DrawIndex",
+    "SV_DeviceIndex",
     "SV_RenderTargetArrayIndex",
     "SV_SampleIndex",
     "SV_StencilRef",

tests/spirv/device-index-glsl-syntax.slang

@@ -0,0 +1,16 @@
+//TEST:SIMPLE(filecheck=SPIRV): -target spirv -entry main -stage fragment -allow-glsl
+//TEST:SIMPLE(filecheck=GLSL): -target glsl -entry main -stage fragment -allow-glsl
+
+// SPIRV: OpDecorate %{{.*}} BuiltIn DeviceIndex
+// GLSL: gl_DeviceIndex
+
+struct PSIn
+{
+    float3 color;
+}
+
+[shader("fragment")]
+float4 main(PSIn pin)
+{
+    return float4(pin.color, (float)gl_DeviceIndex);
+}

tests/spirv/device-index-hlsl-syntax.slang

@@ -0,0 +1,17 @@
+//TEST:SIMPLE(filecheck=SPIRV): -target spirv -entry main
+//TEST:SIMPLE(filecheck=GLSL): -target glsl -entry main
+
+// SPIRV: OpDecorate %{{.*}} BuiltIn DeviceIndex
+// GLSL: gl_DeviceIndex
+
+struct PSIn
+{
+    float3 color;
+    int deviceIndex : SV_DeviceIndex;
+}
+
+[shader("fragment")]
+float4 main(PSIn pin)
+{
+    return float4(pin.color, (float)pin.deviceIndex);
+}