Add WaveGetLane* support for Metal and WGSL (#6371)

* support WaveGetLane* for WGSL and Metal

* update test and glsl support

* address review comments and fix metal test

* add missing pragma guard

* update test

* Revert "update test"

This reverts commit f2b97e91c29de154190710580c343bd0764aedbb.

* update failing glsl metal test and added new test

* make hlsl and glsl outputs similar

* update test

* disable tests for Metal and cleanup

* comment fix

* add expected failures

* correct expected failures list

* remove expected failure

* add tests to expected failure

---------

Co-authored-by: Yong He <yonghe@outlook.com>

18 files changed, 160 insertions, 101 deletions

diff --git a/source/slang/core.meta.slang b/source/slang/core.meta.slang
index da1b47e13..e2fb8bbf2 100644
--- a/source/slang/core.meta.slang
+++ b/source/slang/core.meta.slang
@@ -440,8 +440,8 @@ attribute_syntax [Differentiable(order:int = 0)] : BackwardDifferentiableAttribu
 __intrinsic_op($(kIROp_RequirePrelude))
 void __requirePrelude(constexpr String preludeText);
 
-__intrinsic_op($(kIROp_RequireGLSLExtension))
-void __requireGLSLExtension(constexpr String preludeText);
+__intrinsic_op($(kIROp_RequireTargetExtension))
+void __requireTargetExtension(constexpr String preludeText);
 
 /// @experimetal
 /// Perform a compile-time condition check and emit a compile-time error if the condition is false.
diff --git a/source/slang/glsl.meta.slang b/source/slang/glsl.meta.slang
index eed6cc690..2a89f2b66 100644
--- a/source/slang/glsl.meta.slang
+++ b/source/slang/glsl.meta.slang
@@ -4296,7 +4296,7 @@ __generic<T : __BuiltinType>
     case glsl:
     {
         if (__type_equals<T, float>())
-            __requireGLSLExtension("GL_EXT_shader_atomic_float");
+            __requireTargetExtension("GL_EXT_shader_atomic_float");
     }
     case spirv:
         if (__type_equals<T, float>())
@@ -4318,7 +4318,7 @@ __generic<T : __BuiltinType>
     case glsl:
     {
         if (__type_equals<T, float>())
-            __requireGLSLExtension("GL_EXT_shader_atomic_float2");
+            __requireTargetExtension("GL_EXT_shader_atomic_float2");
     }
     case spirv:
         if (__type_equals<T, float>())
@@ -4758,7 +4758,7 @@ void requireGLSLExtForRayTracingBuiltin()
     __target_switch
     {
     case glsl:
-        __requireGLSLExtension("GL_EXT_ray_tracing");
+        __requireTargetExtension("GL_EXT_ray_tracing");
         __intrinsic_asm "";
     default:
         return;
@@ -6304,22 +6304,22 @@ public void traceRayMotionNV(
 __generic<T : __BuiltinType>
 [ForceInline]
 void typeRequireChecks_shader_subgroup_GLSL() {
-    // the following is a seperate function call, since else the `__requireGLSLExtension` and associated __intrinsic_asm is ignored if the calling function also calls an __intrinsic_asm
+    // the following is a seperate function call, since else the `__requireTargetExtension` and associated __intrinsic_asm is ignored if the calling function also calls an __intrinsic_asm
     __target_switch
     {
     case glsl:
         if (__type_equals<T, half>()
             || __type_equals<T, float16_t>()
-            ) __requireGLSLExtension("GL_EXT_shader_subgroup_extended_types_float16");
+            ) __requireTargetExtension("GL_EXT_shader_subgroup_extended_types_float16");
         else if (__type_equals<T, uint8_t>()
             || __type_equals<T, int8_t>()
-            ) __requireGLSLExtension("GL_EXT_shader_subgroup_extended_types_int8");
+            ) __requireTargetExtension("GL_EXT_shader_subgroup_extended_types_int8");
         else if (__type_equals<T, uint16_t>()
             || __type_equals<T, int16_t>()
-            ) __requireGLSLExtension("GL_EXT_shader_subgroup_extended_types_int16");
+            ) __requireTargetExtension("GL_EXT_shader_subgroup_extended_types_int16");
         else if (__type_equals<T, uint64_t>()
             || __type_equals<T, int64_t>()
-            ) __requireGLSLExtension("GL_EXT_shader_subgroup_extended_types_int64");
+            ) __requireTargetExtension("GL_EXT_shader_subgroup_extended_types_int64");
 
         __intrinsic_asm "";
     }
@@ -6327,7 +6327,7 @@ void typeRequireChecks_shader_subgroup_GLSL() {
 
 __generic<T : __BuiltinType>
 void shader_subgroup_preamble() {
-    // checks needed for shader_subgroup functions; __requireGLSLExtension does not work 
+    // checks needed for shader_subgroup functions; __requireTargetExtension does not work
     // (does not add the ext specified correctly to the compile output; using extended type
     // will result in error for using the type)
     __target_switch
@@ -6347,14 +6347,14 @@ void requireGLSLExtForSubgroupBasicBuiltin() {
     __target_switch
     {
     case glsl:
-        __requireGLSLExtension("GL_KHR_shader_subgroup_basic");
+        __requireTargetExtension("GL_KHR_shader_subgroup_basic");
         __intrinsic_asm "";
     default:
         return;
     }
 }
 
-[require(cpp_cuda_glsl_hlsl_spirv_wgsl, subgroup_basic)]
+[require(cpp_cuda_glsl_hlsl_metal_spirv_wgsl, subgroup_basic)]
 void setupExtForSubgroupBasicBuiltIn() {
     __target_switch
     {
@@ -6371,7 +6371,7 @@ void requireGLSLExtForSubgroupBallotBuiltin() {
     __target_switch
     {
     case glsl:
-        __requireGLSLExtension("GL_KHR_shader_subgroup_ballot");
+        __requireTargetExtension("GL_KHR_shader_subgroup_ballot");
         __intrinsic_asm "";
     default:
         return;
@@ -6429,7 +6429,8 @@ public property uint gl_SubgroupID
 
 public property uint gl_SubgroupSize
 {
-    [require(cpp_cuda_glsl_hlsl_spirv_wgsl, subgroup_basic)]
+    [ForceInline]
+    [require(cpp_cuda_glsl_hlsl_metal_spirv_wgsl, subgroup_basic)]
     get {
         setupExtForSubgroupBasicBuiltIn();
         return WaveGetLaneCount();
@@ -6438,7 +6439,8 @@ public property uint gl_SubgroupSize
 
 public property uint gl_SubgroupInvocationID
 {
-    [require(cpp_cuda_glsl_hlsl_spirv_wgsl, subgroup_basic)]
+    [ForceInline]
+    [require(cpp_cuda_glsl_hlsl_metal_spirv_wgsl, subgroup_basic)]
     get {
         setupExtForSubgroupBasicBuiltIn();
         return WaveGetLaneIndex();
@@ -8388,8 +8390,8 @@ void typeRequireChecks_atomic_using_float0_tier()
     {
     case glsl:
     {
-        if (__type_equals<T, uint64_t>() || __type_equals<T, int64_t>()) 
-            __requireGLSLExtension("GL_EXT_shader_atomic_int64");  
+        if (__type_equals<T, uint64_t>() || __type_equals<T, int64_t>())
+            __requireTargetExtension("GL_EXT_shader_atomic_int64");
     }
     case spirv:
         return; 
@@ -8405,16 +8407,16 @@ void typeRequireChecks_atomic_using_float1_tier()
     case glsl:
     {
         if (__type_equals<T, float>()) 
-            __requireGLSLExtension("GL_EXT_shader_atomic_float");
+            __requireTargetExtension("GL_EXT_shader_atomic_float");
         else if (__type_equals<T, half>() || __type_equals<T, float16_t>())
         {
-            __requireGLSLExtension("GL_EXT_shader_atomic_float2");
-            __requireGLSLExtension("GL_EXT_shader_explicit_arithmetic_types");
+            __requireTargetExtension("GL_EXT_shader_atomic_float2");
+            __requireTargetExtension("GL_EXT_shader_explicit_arithmetic_types");
         }
         else if (__type_equals<T, double>()) 
-            __requireGLSLExtension("GL_EXT_shader_atomic_float");
+            __requireTargetExtension("GL_EXT_shader_atomic_float");
         else if (__type_equals<T, uint64_t>() || __type_equals<T, int64_t>())
-            __requireGLSLExtension("GL_EXT_shader_atomic_int64");
+            __requireTargetExtension("GL_EXT_shader_atomic_int64");
     }
     case spirv:
         return;
@@ -8430,16 +8432,16 @@ void typeRequireChecks_atomic_using_float2_tier()
     case glsl:
     {    
         if (__type_equals<T, float>()) 
-            __requireGLSLExtension("GL_EXT_shader_atomic_float2");
+            __requireTargetExtension("GL_EXT_shader_atomic_float2");
         else if (__type_equals<T, half>() || __type_equals<T, float16_t>())
         {
-            __requireGLSLExtension("GL_EXT_shader_atomic_float2");
-            __requireGLSLExtension("GL_EXT_shader_explicit_arithmetic_types");
+            __requireTargetExtension("GL_EXT_shader_atomic_float2");
+            __requireTargetExtension("GL_EXT_shader_explicit_arithmetic_types");
         }
         else if (__type_equals<T, double>()) 
-            __requireGLSLExtension("GL_EXT_shader_atomic_float2");
-        else if (__type_equals<T, uint64_t>() || __type_equals<T, int64_t>()) 
-             __requireGLSLExtension("GL_EXT_shader_atomic_int64");        
+            __requireTargetExtension("GL_EXT_shader_atomic_float2");
+        else if (__type_equals<T, uint64_t>() || __type_equals<T, int64_t>())
+             __requireTargetExtension("GL_EXT_shader_atomic_int64");
     }
     case spirv: 
         return; 
diff --git a/source/slang/hlsl.meta.slang b/source/slang/hlsl.meta.slang
index a2b685b69..c9f3fb533 100644
--- a/source/slang/hlsl.meta.slang
+++ b/source/slang/hlsl.meta.slang
@@ -3,8 +3,14 @@
 
 typedef uint UINT;
 
-__intrinsic_op($(kIROp_RequireGLSLExtension))
-void __requireGLSLExtension(String extensionName);
+__intrinsic_op($(kIROp_RequireTargetExtension))
+void __requireTargetExtension(constexpr String extensionName);
+
+/// Built-in values or system value semantics represented as in/out global variables.
+/// This allows the built-ins to be arbitrarily used from a global scope without being
+/// explicitly passed as entry point parameters.
+in uint __builtinWaveLaneIndex : SV_WaveLaneIndex;
+in uint __builtinWaveLaneCount : SV_WaveLaneCount;
 
 //@public:
 /// Represents an interface for buffer data layout.
@@ -3505,7 +3511,7 @@ extension _Texture<T,Shape,isArray,0,sampleCount,0,isShadow,isCombined,format>
             __intrinsic_asm "<invalid intrinsics>";
         case glsl:
             if (isCombined == 0)
-                __requireGLSLExtension("GL_EXT_samplerless_texture_functions");
+                __requireTargetExtension("GL_EXT_samplerless_texture_functions");
             __intrinsic_asm "$ctexelFetch($0, ($1).$w1b, ($1).$w1e)$z";
         case spirv:
             const int lodLoc = Shape.dimensions+isArray;
@@ -3569,7 +3575,7 @@ extension _Texture<T,Shape,isArray,0,sampleCount,0,isShadow,isCombined,format>
                 __intrinsic_asm ".Load";
             case glsl:
                 if (isCombined == 0)
-                    __requireGLSLExtension("GL_EXT_samplerless_texture_functions");
+                    __requireTargetExtension("GL_EXT_samplerless_texture_functions");
                 __intrinsic_asm "$ctexelFetchOffset($0, ($1).$w1b, ($1).$w1e, ($2))$z";
             case spirv:
                 const int lodLoc = Shape.dimensions+isArray;
@@ -3625,7 +3631,7 @@ extension _Texture<T,Shape,isArray,0,sampleCount,0,isShadow,isCombined,format>
                     return Load(__makeVector(location, 0));
                 case glsl:
                     if (isCombined == 0)
-                        __requireGLSLExtension("GL_EXT_samplerless_texture_functions");
+                        __requireTargetExtension("GL_EXT_samplerless_texture_functions");
 
                     return Load(__makeVector(location, 0));
                 case spirv:
@@ -3702,7 +3708,7 @@ extension _Texture<T,Shape,isArray,1,sampleCount,0,isShadow,isCombined,format>
                 __intrinsic_asm "<Not supported>";
             case glsl:
                 if (isCombined == 0)
-                    __requireGLSLExtension("GL_EXT_samplerless_texture_functions");
+                    __requireTargetExtension("GL_EXT_samplerless_texture_functions");
                 __intrinsic_asm "$ctexelFetch($0, $1, ($2))$z";
             case spirv:
                 if (isCombined != 0)
@@ -3752,7 +3758,7 @@ extension _Texture<T,Shape,isArray,1,sampleCount,0,isShadow,isCombined,format>
                 __intrinsic_asm ".Load";
             case glsl:
                 if (isCombined == 0)
-                    __requireGLSLExtension("GL_EXT_samplerless_texture_functions");
+                    __requireTargetExtension("GL_EXT_samplerless_texture_functions");
                 __intrinsic_asm "$ctexelFetchOffset($0, $1, ($2), ($3))$z";
             case spirv:
                 if (isCombined != 0)
@@ -3807,7 +3813,7 @@ extension _Texture<T,Shape,isArray,1,sampleCount,0,isShadow,isCombined,format>
                     return Load(location, 0);
                 case glsl:
                     if (isCombined == 0)
-                        __requireGLSLExtension("GL_EXT_samplerless_texture_functions");
+                        __requireTargetExtension("GL_EXT_samplerless_texture_functions");
                     return Load(location, 0);
             }
         }
@@ -3830,7 +3836,7 @@ extension _Texture<T,Shape,isArray,1,sampleCount,0,isShadow,isCombined,format>
                     return Load(location, sampleIndex);
                 case glsl:
                     if (isCombined == 0)
-                        __requireGLSLExtension("GL_EXT_samplerless_texture_functions");
+                        __requireTargetExtension("GL_EXT_samplerless_texture_functions");
                     return Load(location, sampleIndex);
             }
         }
@@ -13913,7 +13919,7 @@ T WaveMaskSum(WaveMask mask, T expr)
     __target_switch
     {
     case glsl:
-        if (__isHalf<T>()) __requireGLSLExtension("GL_EXT_shader_subgroup_extended_types_float16");
+        if (__isHalf<T>()) __requireTargetExtension("GL_EXT_shader_subgroup_extended_types_float16");
         __intrinsic_asm "subgroupAdd($1)";
     case cuda: __intrinsic_asm "_waveSum($0, $1)";
     case hlsl: __intrinsic_asm "WaveActiveSum($1)";
@@ -13940,7 +13946,7 @@ vector<T,N> WaveMaskSum(WaveMask mask, vector<T,N> expr)
     __target_switch
     {
     case glsl:
-        if (__isHalf<T>()) __requireGLSLExtension("GL_EXT_shader_subgroup_extended_types_float16");
+        if (__isHalf<T>()) __requireTargetExtension("GL_EXT_shader_subgroup_extended_types_float16");
         __intrinsic_asm "subgroupAdd($1)";
     case cuda: __intrinsic_asm "_waveSumMultiple($0, $1)";
     case hlsl: __intrinsic_asm "WaveActiveSum($1)";
@@ -13979,7 +13985,7 @@ bool WaveMaskAllEqual(WaveMask mask, T value)
     __target_switch
     {
     case glsl:
-        if (__isHalf<T>()) __requireGLSLExtension("GL_EXT_shader_subgroup_extended_types_float16");
+        if (__isHalf<T>()) __requireTargetExtension("GL_EXT_shader_subgroup_extended_types_float16");
         __intrinsic_asm "subgroupAllEqual($1)";
     case hlsl:
         __intrinsic_asm "WaveActiveAllEqual($1)";
@@ -14003,7 +14009,7 @@ bool WaveMaskAllEqual(WaveMask mask, vector<T,N> value)
     __target_switch
     {
     case glsl:
-        if (__isHalf<T>()) __requireGLSLExtension("GL_EXT_shader_subgroup_extended_types_float16");
+        if (__isHalf<T>()) __requireTargetExtension("GL_EXT_shader_subgroup_extended_types_float16");
         __intrinsic_asm "subgroupAllEqual($1)";
     case hlsl:
         __intrinsic_asm "WaveActiveAllEqual($1)";
@@ -14040,7 +14046,7 @@ T WaveMaskPrefixProduct(WaveMask mask, T expr)
     __target_switch
     {
     case glsl:
-        if (__isHalf<T>()) __requireGLSLExtension("GL_EXT_shader_subgroup_extended_types_float16");
+        if (__isHalf<T>()) __requireTargetExtension("GL_EXT_shader_subgroup_extended_types_float16");
         __intrinsic_asm "subgroupExclusiveMul($1)";
     case cuda: __intrinsic_asm "_wavePrefixProduct($0, $1)";
     case hlsl: __intrinsic_asm "WavePrefixProduct($1)";
@@ -14067,7 +14073,7 @@ vector<T,N> WaveMaskPrefixProduct(WaveMask mask, vector<T,N> expr)
     __target_switch
     {
     case glsl:
-        if (__isHalf<T>()) __requireGLSLExtension("GL_EXT_shader_subgroup_extended_types_float16");
+        if (__isHalf<T>()) __requireTargetExtension("GL_EXT_shader_subgroup_extended_types_float16");
         __intrinsic_asm "subgroupExclusiveMul($1)";
     case cuda: __intrinsic_asm "_wavePrefixProductMultiple($0, $1)";
     case hlsl: __intrinsic_asm "WavePrefixProduct($1)";
@@ -14105,7 +14111,7 @@ T WaveMaskPrefixSum(WaveMask mask, T expr)
     __target_switch
     {
     case glsl:
-        if (__isHalf<T>()) __requireGLSLExtension("GL_EXT_shader_subgroup_extended_types_float16");
+        if (__isHalf<T>()) __requireTargetExtension("GL_EXT_shader_subgroup_extended_types_float16");
         __intrinsic_asm "subgroupExclusiveAdd($1)";
     case cuda: __intrinsic_asm "_wavePrefixSum($0, $1)";
     case hlsl: __intrinsic_asm "WavePrefixSum($1)";
@@ -14133,7 +14139,7 @@ vector<T,N> WaveMaskPrefixSum(WaveMask mask, vector<T,N> expr)
     __target_switch
     {
     case glsl:
-        if (__isHalf<T>()) __requireGLSLExtension("GL_EXT_shader_subgroup_extended_types_float16");
+        if (__isHalf<T>()) __requireTargetExtension("GL_EXT_shader_subgroup_extended_types_float16");
         __intrinsic_asm "subgroupExclusiveAdd($1)";
     case cuda: __intrinsic_asm "_wavePrefixSumMultiple($0, $1)";
     case hlsl: __intrinsic_asm "WavePrefixSum($1)";
@@ -14761,7 +14767,7 @@ T WaveActive$(opName.hlslName)(T expr)
     __target_switch
     {
     case glsl:
-        if (__isHalf<T>()) __requireGLSLExtension("GL_EXT_shader_subgroup_extended_types_float16");
+        if (__isHalf<T>()) __requireTargetExtension("GL_EXT_shader_subgroup_extended_types_float16");
         __intrinsic_asm "subgroup$(opName.glslName)($0)";
     case hlsl: __intrinsic_asm "WaveActive$(opName.hlslName)";
     case metal: __intrinsic_asm "simd_$(opName.metalName)";
@@ -14796,7 +14802,7 @@ vector<T,N> WaveActive$(opName.hlslName)(vector<T,N> expr)
     __target_switch
     {
     case glsl:
-        if (__isHalf<T>()) __requireGLSLExtension("GL_EXT_shader_subgroup_extended_types_float16");
+        if (__isHalf<T>()) __requireTargetExtension("GL_EXT_shader_subgroup_extended_types_float16");
         __intrinsic_asm "subgroup$(opName.glslName)($0)";
     case hlsl: __intrinsic_asm "WaveActive$(opName.hlslName)";
     case metal: __intrinsic_asm "simd_$(opName.metalName)";
@@ -15018,7 +15024,8 @@ uint WaveActiveCountBits(bool value)
 __glsl_extension(GL_KHR_shader_subgroup_basic)
 __spirv_version(1.3)
 [NonUniformReturn]
-[require(cuda_glsl_hlsl_spirv, subgroup_basic)]
+[ForceInline]
+[require(cuda_glsl_hlsl_metal_spirv_wgsl, subgroup_basic)]
 uint WaveGetLaneCount()
 {
     __target_switch
@@ -15032,6 +15039,11 @@ uint WaveGetLaneCount()
             OpCapability GroupNonUniform;
             result:$$uint = OpLoad builtin(SubgroupSize:uint)
         };
+    case metal:
+        return __builtinWaveLaneCount;
+    case wgsl:
+        __requireTargetExtension("subgroups");
+        return __builtinWaveLaneCount;
     }
 }
 
@@ -15039,7 +15051,8 @@ uint WaveGetLaneCount()
 __glsl_extension(GL_KHR_shader_subgroup_basic)
 __spirv_version(1.3)
 [NonUniformReturn]
-[require(cuda_glsl_hlsl_spirv, subgroup_basic)]
+[ForceInline]
+[require(cuda_glsl_hlsl_metal_spirv_wgsl, subgroup_basic)]
 uint WaveGetLaneIndex()
 {
     __target_switch
@@ -15053,6 +15066,11 @@ uint WaveGetLaneIndex()
             OpCapability GroupNonUniform;
             result:$$uint = OpLoad builtin(SubgroupLocalInvocationId:uint)
         };
+    case metal:
+        return __builtinWaveLaneIndex;
+    case wgsl:
+        __requireTargetExtension("subgroups");
+        return __builtinWaveLaneIndex;
     }
 }
 
@@ -15122,7 +15140,7 @@ T WavePrefixProduct(T expr)
     __target_switch
     {
     case glsl:
-        if (__isHalf<T>()) __requireGLSLExtension("GL_EXT_shader_subgroup_extended_types_float16");
+        if (__isHalf<T>()) __requireTargetExtension("GL_EXT_shader_subgroup_extended_types_float16");
         __intrinsic_asm "subgroupExclusiveMul($0)";
     case hlsl: __intrinsic_asm "WavePrefixProduct";
     case metal: __intrinsic_asm "simd_prefix_exclusive_product";
@@ -15158,7 +15176,7 @@ vector<T,N> WavePrefixProduct(vector<T,N> expr)
     __target_switch
     {
     case glsl:
-        if (__isHalf<T>()) __requireGLSLExtension("GL_EXT_shader_subgroup_extended_types_float16");
+        if (__isHalf<T>()) __requireTargetExtension("GL_EXT_shader_subgroup_extended_types_float16");
         __intrinsic_asm "subgroupExclusiveMul($0)";
     case hlsl: __intrinsic_asm "WavePrefixProduct";
     case metal: __intrinsic_asm "simd_prefix_exclusive_product";
@@ -15209,7 +15227,7 @@ T WavePrefixSum(T expr)
     __target_switch
     {
     case glsl:
-        if (__isHalf<T>()) __requireGLSLExtension("GL_EXT_shader_subgroup_extended_types_float16");
+        if (__isHalf<T>()) __requireTargetExtension("GL_EXT_shader_subgroup_extended_types_float16");
         __intrinsic_asm "subgroupExclusiveAdd($0)";
     case hlsl: __intrinsic_asm "WavePrefixSum";
     case metal: __intrinsic_asm "simd_prefix_exclusive_sum";
@@ -15241,7 +15259,7 @@ vector<T,N> WavePrefixSum(vector<T,N> expr)
     __target_switch
     {
     case glsl:
-        if (__isHalf<T>()) __requireGLSLExtension("GL_EXT_shader_subgroup_extended_types_float16");
+        if (__isHalf<T>()) __requireTargetExtension("GL_EXT_shader_subgroup_extended_types_float16");
         __intrinsic_asm "subgroupExclusiveAdd($0)";
     case hlsl: __intrinsic_asm "WavePrefixSum";
     case metal: __intrinsic_asm "simd_prefix_exclusive_sum";
@@ -15292,7 +15310,7 @@ T WaveReadLaneFirst(T expr)
     __target_switch
     {
     case glsl:
-        if (__isHalf<T>()) __requireGLSLExtension("GL_EXT_shader_subgroup_extended_types_float16");
+        if (__isHalf<T>()) __requireTargetExtension("GL_EXT_shader_subgroup_extended_types_float16");
         __intrinsic_asm "subgroupBroadcastFirst($0)";
     case hlsl: __intrinsic_asm "WaveReadLaneFirst";
     case metal: __intrinsic_asm "simd_broadcast_first";
@@ -15314,7 +15332,7 @@ vector<T,N> WaveReadLaneFirst(vector<T,N> expr)
     __target_switch
     {
     case glsl:
-        if (__isHalf<T>()) __requireGLSLExtension("GL_EXT_shader_subgroup_extended_types_float16");
+        if (__isHalf<T>()) __requireTargetExtension("GL_EXT_shader_subgroup_extended_types_float16");
         __intrinsic_asm "subgroupBroadcastFirst($0)";
     case hlsl: __intrinsic_asm "WaveReadLaneFirst";
     case metal: __intrinsic_asm "simd_broadcast_first";
@@ -15360,7 +15378,7 @@ T WaveBroadcastLaneAt(T value, constexpr int lane)
     __target_switch
     {
     case glsl:
-        if (__isHalf<T>()) __requireGLSLExtension("GL_EXT_shader_subgroup_extended_types_float16");
+        if (__isHalf<T>()) __requireTargetExtension("GL_EXT_shader_subgroup_extended_types_float16");
         __intrinsic_asm "subgroupBroadcast($0, $1)";
     case hlsl: __intrinsic_asm "WaveReadLaneAt";
     case metal: __intrinsic_asm "simd_broadcast($0, ushort($1))";
@@ -15384,7 +15402,7 @@ vector<T,N> WaveBroadcastLaneAt(vector<T,N> value, constexpr int lane)
     __target_switch
     {
     case glsl:
-        if (__isHalf<T>()) __requireGLSLExtension("GL_EXT_shader_subgroup_extended_types_float16");
+        if (__isHalf<T>()) __requireTargetExtension("GL_EXT_shader_subgroup_extended_types_float16");
         __intrinsic_asm "subgroupBroadcast($0, $1)";
     case hlsl: __intrinsic_asm "WaveReadLaneAt";
     case metal: __intrinsic_asm "simd_broadcast($0, ushort($1))";
@@ -15426,7 +15444,7 @@ T WaveReadLaneAt(T value, int lane)
     __target_switch
     {
     case glsl:
-        if (__isHalf<T>()) __requireGLSLExtension("GL_EXT_shader_subgroup_extended_types_float16");
+        if (__isHalf<T>()) __requireTargetExtension("GL_EXT_shader_subgroup_extended_types_float16");
         __intrinsic_asm "subgroupShuffle($0, $1)";
     case hlsl: __intrinsic_asm "WaveReadLaneAt";
     case metal: __intrinsic_asm "simd_shuffle($0, ushort($1))";
@@ -15449,7 +15467,7 @@ vector<T,N> WaveReadLaneAt(vector<T,N> value, int lane)
     __target_switch
     {
     case glsl:
-        if (__isHalf<T>()) __requireGLSLExtension("GL_EXT_shader_subgroup_extended_types_float16");
+        if (__isHalf<T>()) __requireTargetExtension("GL_EXT_shader_subgroup_extended_types_float16");
         __intrinsic_asm "subgroupShuffle($0, $1)";
     case hlsl: __intrinsic_asm "WaveReadLaneAt";
     case metal: __intrinsic_asm "simd_shuffle($0, ushort($1))";
@@ -15492,7 +15510,7 @@ T WaveShuffle(T value, int lane)
     __target_switch
     {
     case glsl:
-        if (__isHalf<T>()) __requireGLSLExtension("GL_EXT_shader_subgroup_extended_types_float16");
+        if (__isHalf<T>()) __requireTargetExtension("GL_EXT_shader_subgroup_extended_types_float16");
         __intrinsic_asm "subgroupShuffle($0, $1)";
     case hlsl: __intrinsic_asm "WaveReadLaneAt";
     case metal: __intrinsic_asm "simd_shuffle($0, ushort($1))";
@@ -15516,7 +15534,7 @@ vector<T,N> WaveShuffle(vector<T,N> value, int lane)
     __target_switch
     {
     case glsl:
-        if (__isHalf<T>()) __requireGLSLExtension("GL_EXT_shader_subgroup_extended_types_float16");
+        if (__isHalf<T>()) __requireTargetExtension("GL_EXT_shader_subgroup_extended_types_float16");
         __intrinsic_asm "subgroupShuffle($0, $1)";
     case hlsl: __intrinsic_asm "WaveReadLaneAt";
     case metal: __intrinsic_asm "simd_shuffle($0, ushort($1))";
@@ -16158,7 +16176,7 @@ extension _Texture<T, __ShapeBuffer, 0, 0, 0, $(aa), 0, 0, format>
         {
         case hlsl: __intrinsic_asm ".GetDimensions";
         case glsl:
-            __requireGLSLExtension("GL_EXT_samplerless_texture_functions");
+            __requireTargetExtension("GL_EXT_samplerless_texture_functions");
             __intrinsic_asm "($1 = $(glslTextureSizeFunc)($0))";
         case metal: __intrinsic_asm "(*($1) = $0.get_width())";
         case spirv:
@@ -16178,7 +16196,7 @@ extension _Texture<T, __ShapeBuffer, 0, 0, 0, $(aa), 0, 0, format>
         case hlsl: __intrinsic_asm ".Load";
         case metal: __intrinsic_asm "$c$0.read(uint($1))$z";
         case glsl:
-            __requireGLSLExtension("GL_EXT_samplerless_texture_functions");
+            __requireTargetExtension("GL_EXT_samplerless_texture_functions");
             __intrinsic_asm "$(glslLoadFuncName)($0, $1)$z";
         case spirv: return spirv_asm {
                 %sampled:__sampledType(T) = $(spvLoadInstName) $this $location;
diff --git a/source/slang/slang-core-module-textures.cpp b/source/slang/slang-core-module-textures.cpp
index 22c1fc63f..f703a8a3b 100644
--- a/source/slang/slang-core-module-textures.cpp
+++ b/source/slang/slang-core-module-textures.cpp
@@ -439,7 +439,7 @@ void TextureTypeInfo::writeGetDimensionFunctions()
                     }
                 };
                 glsl << "if (isCombined == 0) { "
-                        "__requireGLSLExtension(\"GL_EXT_samplerless_texture_functions\"); }\n";
+                        "__requireTargetExtension(\"GL_EXT_samplerless_texture_functions\"); }\n";
                 glsl << "if (access == " << kCoreModule_ResourceAccessReadOnly
                      << ") __intrinsic_asm \"";
                 emitIntrinsic(toSlice("textureSize"), !isMultisample);
diff --git a/source/slang/slang-emit-c-like.cpp b/source/slang/slang-emit-c-like.cpp
index 946e9c429..1c48d98ef 100644
--- a/source/slang/slang-emit-c-like.cpp
+++ b/source/slang/slang-emit-c-like.cpp
@@ -3061,10 +3061,6 @@ void CLikeSourceEmitter::defaultEmitInstExpr(IRInst* inst, const EmitOpInfo& inO
                 m_requiredPreludes.add(preludeTextInst);
             break;
         }
-    case kIROp_RequireGLSLExtension:
-        {
-            break; // should already have set requirement; case covered for empty intrinsic block
-        }
     case kIROp_RequireComputeDerivative:
         {
             break; // should already have been parsed and used.
@@ -3074,6 +3070,11 @@ void CLikeSourceEmitter::defaultEmitInstExpr(IRInst* inst, const EmitOpInfo& inO
             emitOperand(as<IRGlobalValueRef>(inst)->getOperand(0), getInfo(EmitOp::General));
             break;
         }
+    case kIROp_RequireTargetExtension:
+        {
+            emitRequireExtension(as<IRRequireTargetExtension>(inst));
+            break;
+        }
     default:
         diagnoseUnhandledInst(inst);
         break;
diff --git a/source/slang/slang-emit-c-like.h b/source/slang/slang-emit-c-like.h
index 6fe7f5d34..ca915ab2d 100644
--- a/source/slang/slang-emit-c-like.h
+++ b/source/slang/slang-emit-c-like.h
@@ -678,6 +678,8 @@ protected:
     void _emitCallArgList(IRCall* call, int startingOperandIndex = 1);
     virtual void emitCallArg(IRInst* arg);
 
+    virtual void emitRequireExtension(IRRequireTargetExtension* inst) { SLANG_UNUSED(inst); }
+
     String _generateUniqueName(const UnownedStringSlice& slice);
 
     // Sort witnessTable entries according to the order defined in the witnessed interface type.
diff --git a/source/slang/slang-emit-glsl.cpp b/source/slang/slang-emit-glsl.cpp
index 776c539b4..696830bf2 100644
--- a/source/slang/slang-emit-glsl.cpp
+++ b/source/slang/slang-emit-glsl.cpp
@@ -30,7 +30,7 @@ void GLSLSourceEmitter::_beforeComputeEmitProcessInstruction(
     IRInst* inst,
     IRBuilder& builder)
 {
-    if (auto requireGLSLExt = as<IRRequireGLSLExtension>(inst))
+    if (auto requireGLSLExt = as<IRRequireTargetExtension>(inst))
     {
         _requireGLSLExtension(requireGLSLExt->getExtensionName());
         return;
diff --git a/source/slang/slang-emit-wgsl.cpp b/source/slang/slang-emit-wgsl.cpp
index 13c79e9ac..7c83b194d 100644
--- a/source/slang/slang-emit-wgsl.cpp
+++ b/source/slang/slang-emit-wgsl.cpp
@@ -1696,4 +1696,9 @@ void WGSLSourceEmitter::handleRequiredCapabilitiesImpl(IRInst* inst)
     }
 }
 
+void WGSLSourceEmitter::emitRequireExtension(IRRequireTargetExtension* inst)
+{
+    _requireExtension(inst->getExtensionName());
+}
+
 } // namespace Slang
diff --git a/source/slang/slang-emit-wgsl.h b/source/slang/slang-emit-wgsl.h
index 441933b57..a29f39a1d 100644
--- a/source/slang/slang-emit-wgsl.h
+++ b/source/slang/slang-emit-wgsl.h
@@ -57,6 +57,8 @@ public:
         EmitOpInfo const& inOuterPrec) SLANG_OVERRIDE;
     virtual void emitGlobalParamDefaultVal(IRGlobalParam* varDecl) SLANG_OVERRIDE;
 
+    virtual void emitRequireExtension(IRRequireTargetExtension* inst) SLANG_OVERRIDE;
+
     virtual void handleRequiredCapabilitiesImpl(IRInst* inst) SLANG_OVERRIDE;
 
     void emit(const AddressSpace addressSpace);
diff --git a/source/slang/slang-emit.cpp b/source/slang/slang-emit.cpp
index 847c5b55c..ddb4ea67a 100644
--- a/source/slang/slang-emit.cpp
+++ b/source/slang/slang-emit.cpp
@@ -100,7 +100,7 @@
 #include "slang-ir-strip-default-construct.h"
 #include "slang-ir-strip-legalization-insts.h"
 #include "slang-ir-synthesize-active-mask.h"
-#include "slang-ir-translate-glsl-global-var.h"
+#include "slang-ir-translate-global-varying-var.h"
 #include "slang-ir-uniformity.h"
 #include "slang-ir-user-type-hint.h"
 #include "slang-ir-validate.h"
@@ -318,7 +318,7 @@ struct RequiredLoweringPassSet
     bool bindingQuery;
     bool meshOutput;
     bool higherOrderFunc;
-    bool glslGlobalVar;
+    bool globalVaryingVar;
     bool glslSSBO;
     bool byteAddressBuffer;
     bool dynamicResource;
@@ -422,7 +422,7 @@ void calcRequiredLoweringPassSet(
     case kIROp_GlobalInputDecoration:
     case kIROp_GlobalOutputDecoration:
     case kIROp_GetWorkGroupSize:
-        result.glslGlobalVar = true;
+        result.globalVaryingVar = true;
         break;
     case kIROp_BindExistentialSlotsDecoration:
         result.bindExistential = true;
@@ -667,8 +667,8 @@ Result linkAndOptimizeIR(
     if (!isKhronosTarget(targetRequest) && requiredLoweringPassSet.glslSSBO)
         lowerGLSLShaderStorageBufferObjectsToStructuredBuffers(irModule, sink);
 
-    if (requiredLoweringPassSet.glslGlobalVar)
-        translateGLSLGlobalVar(codeGenContext, irModule);
+    if (requiredLoweringPassSet.globalVaryingVar)
+        translateGlobalVaryingVar(codeGenContext, irModule);
 
     if (requiredLoweringPassSet.resolveVaryingInputRef)
         resolveVaryingInputRef(irModule);
diff --git a/source/slang/slang-ir-call-graph.h b/source/slang/slang-ir-call-graph.h
index 4ee642356..b7290ef79 100644
--- a/source/slang/slang-ir-call-graph.h
+++ b/source/slang/slang-ir-call-graph.h
@@ -1,3 +1,6 @@
+// slang-ir-call-graph.h
+#pragma once
+
 #include "slang-ir-clone.h"
 #include "slang-ir-insts.h"
 
diff --git a/source/slang/slang-ir-inst-defs.h b/source/slang/slang-ir-inst-defs.h
index 3e2872cb7..714ba146d 100644
--- a/source/slang/slang-ir-inst-defs.h
+++ b/source/slang/slang-ir-inst-defs.h
@@ -407,7 +407,7 @@ INST(WitnessTableEntry, witness_table_entry, 2, 0)
 INST(InterfaceRequirementEntry, interface_req_entry, 2, GLOBAL)
 
 // An inst to represent the workgroup size of the calling entry point.
-// We will materialize this inst during `translateGLSLGlobalVar`.
+// We will materialize this inst during `translateGlobalVaryingVar`.
 INST(GetWorkGroupSize, GetWorkGroupSize, 0, HOISTABLE)
 
 // An inst that returns the current stage of the calling entry point.
@@ -666,7 +666,7 @@ INST_RANGE(TerminatorInst, Return, Unreachable)
 INST(discard, discard, 0, 0)
 
 INST(RequirePrelude, RequirePrelude, 1, 0)
-INST(RequireGLSLExtension, RequireGLSLExtension, 1, 0)
+INST(RequireTargetExtension, RequireTargetExtension, 1, 0)
 INST(RequireComputeDerivative, RequireComputeDerivative, 0, 0)
 INST(StaticAssert, StaticAssert, 2, 0)
 INST(Printf, Printf, 1, 0)
diff --git a/source/slang/slang-ir-insts.h b/source/slang/slang-ir-insts.h
index 4efb7d671..5231592ca 100644
--- a/source/slang/slang-ir-insts.h
+++ b/source/slang/slang-ir-insts.h
@@ -3506,9 +3506,9 @@ struct IRRequirePrelude : IRInst
     UnownedStringSlice getPrelude() { return as<IRStringLit>(getOperand(0))->getStringSlice(); }
 };
 
-struct IRRequireGLSLExtension : IRInst
+struct IRRequireTargetExtension : IRInst
 {
-    IR_LEAF_ISA(RequireGLSLExtension)
+    IR_LEAF_ISA(RequireTargetExtension)
     UnownedStringSlice getExtensionName()
     {
         return as<IRStringLit>(getOperand(0))->getStringSlice();
diff --git a/source/slang/slang-ir-legalize-varying-params.cpp b/source/slang/slang-ir-legalize-varying-params.cpp
index 3b65ee59a..e744969db 100644
--- a/source/slang/slang-ir-legalize-varying-params.cpp
+++ b/source/slang/slang-ir-legalize-varying-params.cpp
@@ -3228,6 +3228,20 @@ protected:
                 result.permittedTypes.add(builder.getBasicType(BaseType::UInt));
                 break;
             }
+        case SystemValueSemanticName::WaveLaneCount:
+            {
+                result.systemValueName = toSlice("threads_per_simdgroup");
+                result.permittedTypes.add(builder.getUIntType());
+                result.permittedTypes.add(builder.getUInt16Type());
+                break;
+            }
+        case SystemValueSemanticName::WaveLaneIndex:
+            {
+                result.systemValueName = toSlice("thread_index_in_simdgroup");
+                result.permittedTypes.add(builder.getUIntType());
+                result.permittedTypes.add(builder.getUInt16Type());
+                break;
+            }
         default:
             m_sink->diagnose(
                 parentVar,
@@ -3845,6 +3859,20 @@ protected:
                 break;
             }
 
+        case SystemValueSemanticName::WaveLaneCount:
+            {
+                result.systemValueName = toSlice("subgroup_size");
+                result.permittedTypes.add(builder.getUIntType());
+                break;
+            }
+
+        case SystemValueSemanticName::WaveLaneIndex:
+            {
+                result.systemValueName = toSlice("subgroup_invocation_id");
+                result.permittedTypes.add(builder.getUIntType());
+                break;
+            }
+
         case SystemValueSemanticName::ViewID:
         case SystemValueSemanticName::ViewportArrayIndex:
         case SystemValueSemanticName::StartVertexLocation:
@@ -3853,7 +3881,6 @@ protected:
                 result.isUnsupported = true;
                 break;
             }
-
         default:
             {
                 m_sink->diagnose(
diff --git a/source/slang/slang-ir-legalize-varying-params.h b/source/slang/slang-ir-legalize-varying-params.h
index e742f3093..0a7c3be8e 100644
--- a/source/slang/slang-ir-legalize-varying-params.h
+++ b/source/slang/slang-ir-legalize-varying-params.h
@@ -68,6 +68,8 @@ void depointerizeInputParams(IRFunc* entryPoint);
     M(Target, SV_Target)                                 \
     M(StartVertexLocation, SV_StartVertexLocation)       \
     M(StartInstanceLocation, SV_StartInstanceLocation)   \
+    M(WaveLaneCount, SV_WaveLaneCount)                   \
+    M(WaveLaneIndex, SV_WaveLaneIndex)                   \
     /* end */
 
 /// A known system-value semantic name that can be applied to a parameter
diff --git a/source/slang/slang-ir-translate-glsl-global-var.cpp b/source/slang/slang-ir-translate-global-varying-var.cpp
index 80ed3c3e4..80f5c42c3 100644
--- a/source/slang/slang-ir-translate-glsl-global-var.cpp
+++ b/source/slang/slang-ir-translate-global-varying-var.cpp
@@ -1,4 +1,4 @@
-#include "slang-ir-translate-glsl-global-var.h"
+#include "slang-ir-translate-global-varying-var.h"
 
 #include "slang-ir-call-graph.h"
 #include "slang-ir-insts.h"
@@ -152,8 +152,8 @@ struct GlobalVarTranslationContext
                 builder.getPtrType(kIROp_ConstRefType, inputStructType, AddressSpace::Input));
             builder.addLayoutDecoration(inputParam, paramLayout);
 
-            // Initialize all global variables.
-            for (Index i = 0; i < inputVars.getCount(); i++)
+            // Initialize all global variables in the order of struct member declaration.
+            for (Index i = inputVars.getCount() - 1; i >= 0; i--)
             {
                 auto input = inputVars[i];
                 setInsertBeforeOrdinaryInst(&builder, firstBlock->getFirstOrdinaryInst());
@@ -373,7 +373,7 @@ struct GlobalVarTranslationContext
     }
 };
 
-void translateGLSLGlobalVar(CodeGenContext* context, IRModule* module)
+void translateGlobalVaryingVar(CodeGenContext* context, IRModule* module)
 {
     GlobalVarTranslationContext ctx;
     ctx.context = context;
diff --git a/source/slang/slang-ir-translate-global-varying-var.h b/source/slang/slang-ir-translate-global-varying-var.h
new file mode 100644
index 000000000..f97683700
--- /dev/null
+++ b/source/slang/slang-ir-translate-global-varying-var.h
@@ -0,0 +1,14 @@
+// slang-ir-translate-global-varying-var.h
+#pragma once
+
+namespace Slang
+{
+
+struct IRModule;
+struct CodeGenContext;
+
+/// Translate GLSL-flavored global in/out variables into
+/// entry point parameters with system value semantics.
+void translateGlobalVaryingVar(CodeGenContext* context, IRModule* module);
+
+} // namespace Slang
diff --git a/source/slang/slang-ir-translate-glsl-global-var.h b/source/slang/slang-ir-translate-glsl-global-var.h
deleted file mode 100644
index 5821ba5c5..000000000
--- a/source/slang/slang-ir-translate-glsl-global-var.h
+++ /dev/null
@@ -1,17 +0,0 @@
-// slang-ir-translate-glsl-global-var.h
-#ifndef SLANG_IR_TRANSLATE_GLSL_GLOBAL_VAR_H
-#define SLANG_IR_TRANSLATE_GLSL_GLOBAL_VAR_H
-
-namespace Slang
-{
-
-struct IRModule;
-struct CodeGenContext;
-
-/// Translate global in/out variables defined in GLSL-flavored code
-/// into entry point parameters with system value semantics.
-void translateGLSLGlobalVar(CodeGenContext* context, IRModule* module);
-
-} // namespace Slang
-
-#endif // SLANG_IR_TRANSLATE_GLSL_GLOBAL_VAR_H