Implement HLSL resource bindings and default type `float4` to `SubpassInput<T>` (#4462)

* Add case to `emitVectorReshape` for `vector<>` type, `scalar` value

1. Add new case
2. Add test

* fix warning

* fix warning

* Implement HLSL resource bindings and default type `float4` to `SubpassInput<T>`

fixes: #4440

1. Removed GLSLInputAttachmentIndexLayout modifier and the somewhat 'hacky' binding model 'Input Attachment' previously relied upon. This was changed to work with the slang-type-layout rules system. This change allows Slang automatic bindings, HLSL bindings, GLSL bindings, and translation of GLSL to and from HLSL bindings to work.
2. Added default argument `float4` to SubpassInput<T>.
3. Merged glsl.meta and hlsl.meta SubpassInput logic.

* fix InputAttachment attribute checks

fix InputAttachment attribute checks for HLSL and GLSL syntax

* remove unused var

* validate attribute correctly

Attributes do not have type information. We must check the type expression to validate attribute usage.

* remove hacky validation

type based validation before types are fully resolved is quite hacky and unstable to changes and wrapped types

* fix warning

* remove redundant `!= nullptr`

* remove extra `!= nullptr`

* fix some warnings/errors

* subpass capability to limit to dxc & remove default values in some functions

* revert logic to previous logic

revert logic to return if we have a binding regardless of if a VarDecl is given the binding

24 files changed, 243 insertions, 175 deletions

diff --git a/source/slang/core.meta.slang b/source/slang/core.meta.slang
index 6b396a621..631c09d19 100644
--- a/source/slang/core.meta.slang
+++ b/source/slang/core.meta.slang
@@ -2475,6 +2475,9 @@ attribute_syntax [vk_index(index : int)] : GLSLIndexAttribute;
 __attributeTarget(FuncDecl)
 attribute_syntax [vk_spirv_instruction(op : int, set : String = "")]     : SPIRVInstructionOpAttribute;
 
+__attributeTarget(VarDeclBase)
+attribute_syntax [vk_input_attachment_index(location : int)] : GLSLInputAttachmentIndexLayoutAttribute;
+
 __attributeTarget(FuncDecl)
 attribute_syntax [spv_target_env_1_3] : SPIRVTargetEnv13Attribute;
 
diff --git a/source/slang/glsl.meta.slang b/source/slang/glsl.meta.slang
index f18e07fbd..85d39493b 100644
--- a/source/slang/glsl.meta.slang
+++ b/source/slang/glsl.meta.slang
@@ -9556,20 +9556,7 @@ ${{{{
     [require(glsl_hlsl_spirv, subpass)]
     public T subpassLoad(__SubpassImpl<T,0> subpass)
     {
-        __target_switch
-        {
-        case hlsl: return subpass.SubpassLoad();
-        case glsl: __intrinsic_asm "subpassLoad($0)";
-        case spirv:
-        {
-            let zeroVec = ivec2(0);
-            return spirv_asm
-            {
-                OpCapability StorageImageReadWithoutFormat;
-                result:$$T = OpImageRead $subpass $zeroVec
-            };
-        }
-        }
+        return subpass.SubpassLoad();
     }
     __generic<T>
     [__NoSideEffect]
@@ -9577,20 +9564,7 @@ ${{{{
     [require(glsl_hlsl_spirv, subpass)]
     public T subpassLoad(__SubpassImpl<T,1> subpass, int sample)
     {
-        __target_switch
-        {
-        case hlsl: return subpass.SubpassLoad(sample);
-        case glsl: __intrinsic_asm "subpassLoad($0, $1)";
-        case spirv:
-        {
-            let zeroVec = ivec2(0);
-            return spirv_asm
-            {
-                OpCapability StorageImageReadWithoutFormat;
-                result:$$T = OpImageRead $subpass $zeroVec Sample $sample
-            };
-        }
-        }
+        return subpass.SubpassLoad(sample);
     }
 
 /// Section 8.19. Shader Invocation Group Functions
diff --git a/source/slang/hlsl.meta.slang b/source/slang/hlsl.meta.slang
index 0a440f986..8509b4005 100644
--- a/source/slang/hlsl.meta.slang
+++ b/source/slang/hlsl.meta.slang
@@ -17304,19 +17304,20 @@ struct __SubpassImpl<T, let isMS:int>
 {
 }
 
-__generic<T, let isMS:int=0>
+__generic<T = float4, let isMS:int=0>
 typealias SubpassInput = __SubpassImpl<T, isMS>;
 
 __generic<T>
 extension __SubpassImpl<T, 0>
 {
     [ForceInline]
-    [require(hlsl_spirv, subpass)]
+    [require(glsl_hlsl_spirv, subpass)]
     T SubpassLoad()
     {
         __target_switch
         {
         case hlsl: __intrinsic_asm "$0.SubpassLoad()";
+        case glsl: __intrinsic_asm "subpassLoad($0)";
         case spirv:
         {
             let zeroVec = int2(0);
@@ -17330,19 +17331,20 @@ extension __SubpassImpl<T, 0>
     }
 }
 
-__generic<T, let isMS:int=1>
+__generic<T = float4, let isMS:int=1>
 typealias SubpassInputMS = __SubpassImpl<T, isMS>;
 
 __generic<T>
 extension __SubpassImpl<T, 1>
 {
     [ForceInline]
-    [require(hlsl_spirv, subpass)]
+    [require(glsl_hlsl_spirv, subpass)]
     T SubpassLoad(int sample)
     {
         __target_switch
         {
         case hlsl: __intrinsic_asm "$0.SubpassLoad($1)";
+        case glsl: __intrinsic_asm "subpassLoad($0, $1)";
         case spirv:
         {
             let zeroVec = int2(0);
diff --git a/source/slang/slang-ast-modifier.h b/source/slang/slang-ast-modifier.h
index 39e167ab8..a4e01477c 100644
--- a/source/slang/slang-ast-modifier.h
+++ b/source/slang/slang-ast-modifier.h
@@ -242,11 +242,6 @@ class GLSLLocationLayoutModifier : public GLSLParsedLayoutModifier
     SLANG_AST_CLASS(GLSLLocationLayoutModifier)
 };
 
-class GLSLInputAttachmentIndexLayoutModifier : public GLSLParsedLayoutModifier
-{
-    SLANG_AST_CLASS(GLSLInputAttachmentIndexLayoutModifier)
-};
-
 class GLSLBufferDataLayoutModifier : public GLSLParsedLayoutModifier
 {
     SLANG_AST_CLASS(GLSLBufferDataLayoutModifier)
@@ -775,6 +770,14 @@ class GLSLSimpleIntegerLayoutAttribute : public Attribute
     int32_t value = 0;
 };
 
+/// [[vk_input_attachment_index]]
+class GLSLInputAttachmentIndexLayoutAttribute : public Attribute
+{
+    SLANG_AST_CLASS(GLSLInputAttachmentIndexLayoutAttribute)
+
+    IntegerLiteralValue location;
+};
+
 // [[vk_location]]
 class GLSLLocationAttribute : public GLSLSimpleIntegerLayoutAttribute 
 {
diff --git a/source/slang/slang-capabilities.capdef b/source/slang/slang-capabilities.capdef
index b011021bc..1511c3a08 100644
--- a/source/slang/slang-capabilities.capdef
+++ b/source/slang/slang-capabilities.capdef
@@ -410,7 +410,7 @@ alias atomicfloat2 = GL_EXT_shader_atomic_float2 | _sm_6_6 + hlsl_nvapi | cpp |
 alias fragmentshaderbarycentric = GL_EXT_fragment_shader_barycentric | _sm_6_1;
 alias shadermemorycontrol = glsl | _spirv_1_0 | _sm_5_0;
 alias shadermemorycontrol_compute = raytracingstages_compute + shadermemorycontrol;
-alias subpass = fragment + any_gfx_target;
+alias subpass = fragment + _sm_6_0 | fragment + any_gfx_target;
 alias waveprefix = _sm_6_5 | _cuda_sm_7_0 | GL_KHR_shader_subgroup_arithmetic;
 alias bufferreference = GL_EXT_buffer_reference;
 alias bufferreference_int64 = bufferreference + GL_EXT_shader_explicit_arithmetic_types_int64;
diff --git a/source/slang/slang-check-modifier.cpp b/source/slang/slang-check-modifier.cpp
index aa30f66ca..7721fedbf 100644
--- a/source/slang/slang-check-modifier.cpp
+++ b/source/slang/slang-check-modifier.cpp
@@ -474,6 +474,17 @@ namespace Slang
             }
             overloadRankAttr->rank = int32_t(rank->getValue());
         }
+        else if (auto inputAttachmentIndexLayoutAttribute = as<GLSLInputAttachmentIndexLayoutAttribute>(attr))
+        {
+            if (attr->args.getCount() != 1)
+                return false;
+    
+            auto location = checkConstantIntVal(attr->args[0]);
+            if(!location)
+                return false;
+
+            inputAttachmentIndexLayoutAttribute->location = location->getValue();
+        }
         else if (auto bindingAttr = as<GLSLBindingAttribute>(attr))
         {
             // This must be vk::binding or gl::binding (as specified in core.meta.slang under vk_binding/gl_binding)
@@ -1105,7 +1116,7 @@ namespace Slang
         case ASTNodeType::GLSLParsedLayoutModifier:
         case ASTNodeType::GLSLConstantIDLayoutModifier:
         case ASTNodeType::GLSLLocationLayoutModifier:
-        case ASTNodeType::GLSLInputAttachmentIndexLayoutModifier:
+        case ASTNodeType::GLSLInputAttachmentIndexLayoutAttribute:
         case ASTNodeType::GLSLOffsetLayoutAttribute:
         case ASTNodeType::GLSLUnparsedLayoutModifier:
         case ASTNodeType::GLSLLayoutModifierGroupMarker:
@@ -1185,7 +1196,7 @@ namespace Slang
         case ASTNodeType::GLSLParsedLayoutModifier:
         case ASTNodeType::GLSLConstantIDLayoutModifier:
         case ASTNodeType::GLSLLocationLayoutModifier:
-        case ASTNodeType::GLSLInputAttachmentIndexLayoutModifier:
+        case ASTNodeType::GLSLInputAttachmentIndexLayoutAttribute:
         case ASTNodeType::GLSLOffsetLayoutAttribute:
         case ASTNodeType::GLSLUnparsedLayoutModifier:
         case ASTNodeType::GLSLLayoutModifierGroupMarker:
diff --git a/source/slang/slang-check-shader.cpp b/source/slang/slang-check-shader.cpp
index 67abb56b7..14495dd6e 100644
--- a/source/slang/slang-check-shader.cpp
+++ b/source/slang/slang-check-shader.cpp
@@ -312,6 +312,8 @@ namespace Slang
     {
         if (as<ResourceType>(type))
             return true;
+        if (as<SubpassInputType>(type))
+            return true;
         if (as<HLSLStructuredBufferTypeBase>(type))
             return true;
         if (as<UntypedBufferResourceType>(type))
diff --git a/source/slang/slang-diagnostic-defs.h b/source/slang/slang-diagnostic-defs.h
index 5b9c3e65a..cb994b904 100644
--- a/source/slang/slang-diagnostic-defs.h
+++ b/source/slang/slang-diagnostic-defs.h
@@ -453,7 +453,6 @@ DIAGNOSTIC(31203, Error, cannotExportIncompleteType, "cannot export incomplete t
 DIAGNOSTIC(31204, Error, incompleteTypeCannotBeUsedInBuffer, "incomplete type '$0' cannot be used in a buffer")
 DIAGNOSTIC(31205, Error, incompleteTypeCannotBeUsedInUniformParameter, "incomplete type '$0' cannot be used in a uniform parameter")
 DIAGNOSTIC(31206, Error, memoryQualifierNotAllowedOnANonImageTypeParameter, "modifier $0 is not allowed on a non image type parameter.")
-DIAGNOSTIC(31207, Error, InputAttachmentIndexOnlyAllowedOnSubpass, "input_attachment_index is only allowed on subpass images.")
 DIAGNOSTIC(31208, Error, requireInputDecoratedVarForParameter, "$0 expects for argument $1 a type which is a shader input (`in`) variable.")
 DIAGNOSTIC(31210, Error, derivativeGroupQuadMustBeMultiple2ForXYThreads, "compute derivative group quad requires thread dispatch count of X and Y to each be at a multiple of 2")
 DIAGNOSTIC(31211, Error, derivativeGroupLinearMustBeMultiple4ForTotalThreadCount, "compute derivative group linear requires total thread dispatch count to be at a multiple of 4")
diff --git a/source/slang/slang-emit-c-like.cpp b/source/slang/slang-emit-c-like.cpp
index 6062875b3..66ee12ca6 100644
--- a/source/slang/slang-emit-c-like.cpp
+++ b/source/slang/slang-emit-c-like.cpp
@@ -3160,9 +3160,14 @@ void CLikeSourceEmitter::emitSemantics(IRInst* inst, bool allowOffsetLayout)
     emitSemanticsImpl(inst, allowOffsetLayout);
 }
 
+void CLikeSourceEmitter::emitDecorationLayoutSemantics(IRInst* inst, char const* uniformSemanticSpelling)
+{
+    emitLayoutSemanticsImpl(inst, uniformSemanticSpelling, EmitLayoutSemanticOption::kPreType);
+}
+
 void CLikeSourceEmitter::emitLayoutSemantics(IRInst* inst, char const* uniformSemanticSpelling)
 {
-    emitLayoutSemanticsImpl(inst, uniformSemanticSpelling);
+    emitLayoutSemanticsImpl(inst, uniformSemanticSpelling, EmitLayoutSemanticOption::kPostType);
 }
 
 void CLikeSourceEmitter::emitRegion(Region* inRegion)
@@ -3959,7 +3964,7 @@ void CLikeSourceEmitter::emitVar(IRVar* varDecl)
     emitType(varType, getName(varDecl));
 
     emitSemantics(varDecl);
-    emitLayoutSemantics(varDecl);
+    emitLayoutSemantics(varDecl, "register");
     emitPostDeclarationAttributesForType(varType);
 
     // TODO: ideally this logic should scan ahead to see if it can find a `store`
@@ -4092,7 +4097,7 @@ void CLikeSourceEmitter::emitGlobalVar(IRGlobalVar* varDecl)
     // global variables.
     //
     emitSemantics(varDecl);
-    emitLayoutSemantics(varDecl);
+    emitLayoutSemantics(varDecl, "register");
 
     if (varDecl->getFirstBlock())
     {
@@ -4155,13 +4160,15 @@ void CLikeSourceEmitter::emitGlobalParam(IRGlobalParam* varDecl)
     SLANG_ASSERT(layout);
 
     emitVarModifiers(layout, varDecl, varType);
+    
+    emitDecorationLayoutSemantics(varDecl, "register");
 
     emitRateQualifiersAndAddressSpace(varDecl);
     emitType(varType, getName(varDecl));
 
     emitSemantics(varDecl);
 
-    emitLayoutSemantics(varDecl);
+    emitLayoutSemantics(varDecl, "register");
 
     // A shader parameter cannot have an initializer,
     // so we do need to consider emitting one here.
diff --git a/source/slang/slang-emit-c-like.h b/source/slang/slang-emit-c-like.h
index ecff57296..07cb4a0bc 100644
--- a/source/slang/slang-emit-c-like.h
+++ b/source/slang/slang-emit-c-like.h
@@ -20,6 +20,13 @@ namespace Slang
 class CLikeSourceEmitter: public SourceEmitterBase
 {
 public:
+
+    enum class EmitLayoutSemanticOption
+    {
+        kPreType,
+        kPostType
+    };
+
     struct Desc
     {
         CodeGenContext* codeGenContext = nullptr;
@@ -344,7 +351,8 @@ public:
     void emitSemantics(IRInst* inst, bool allowOffsets = false);
     void emitSemanticsUsingVarLayout(IRVarLayout* varLayout);
 
-    void emitLayoutSemantics(IRInst* inst, char const* uniformSemanticSpelling = "register");
+    void emitDecorationLayoutSemantics(IRInst* inst, char const* uniformSemanticSpelling);
+    void emitLayoutSemantics(IRInst* inst, char const* uniformSemanticSpelling);
 
         /// Emit high-level language statements from a structured region.
     void emitRegion(Region* inRegion);
@@ -463,7 +471,7 @@ public:
 
     virtual void emitPostDeclarationAttributesForType(IRInst* type) { SLANG_UNUSED(type); }
     virtual bool doesTargetSupportPtrTypes() { return false; }
-    virtual void emitLayoutSemanticsImpl(IRInst* inst, char const* uniformSemanticSpelling = "register") { SLANG_UNUSED(inst); SLANG_UNUSED(uniformSemanticSpelling); }
+    virtual void emitLayoutSemanticsImpl(IRInst* inst, char const* uniformSemanticSpelling, EmitLayoutSemanticOption layoutSemanticOption) { SLANG_UNUSED(inst); SLANG_UNUSED(uniformSemanticSpelling); SLANG_UNUSED(layoutSemanticOption); }
     virtual void emitParameterGroupImpl(IRGlobalParam* varDecl, IRUniformParameterGroupType* type) = 0;
     virtual void emitEntryPointAttributesImpl(IRFunc* irFunc, IREntryPointDecoration* entryPointDecor) = 0;
 
diff --git a/source/slang/slang-emit-cuda.cpp b/source/slang/slang-emit-cuda.cpp
index 2417a64ec..f4b45b7aa 100644
--- a/source/slang/slang-emit-cuda.cpp
+++ b/source/slang/slang-emit-cuda.cpp
@@ -212,9 +212,9 @@ SlangResult CUDASourceEmitter::calcTypeName(IRType* type, CodeGenTarget target,
     return Super::calcTypeName(type, target, out);
 }
 
-void CUDASourceEmitter::emitLayoutSemanticsImpl(IRInst* inst, char const* uniformSemanticSpelling)
+void CUDASourceEmitter::emitLayoutSemanticsImpl(IRInst* inst, char const* uniformSemanticSpelling, EmitLayoutSemanticOption layoutSemanticOption)
 {
-    Super::emitLayoutSemanticsImpl(inst, uniformSemanticSpelling);
+    Super::emitLayoutSemanticsImpl(inst, uniformSemanticSpelling, layoutSemanticOption);
 }
 
 void CUDASourceEmitter::emitParameterGroupImpl(IRGlobalParam* varDecl, IRUniformParameterGroupType* type)
diff --git a/source/slang/slang-emit-cuda.h b/source/slang/slang-emit-cuda.h
index 13a497343..5d76c4ef3 100644
--- a/source/slang/slang-emit-cuda.h
+++ b/source/slang/slang-emit-cuda.h
@@ -63,7 +63,7 @@ public:
 
 protected:
 
-    virtual void emitLayoutSemanticsImpl(IRInst* inst, char const* uniformSemanticSpelling) SLANG_OVERRIDE;
+    virtual void emitLayoutSemanticsImpl(IRInst* inst, char const* uniformSemanticSpelling, EmitLayoutSemanticOption layoutSemanticOption) SLANG_OVERRIDE;
     virtual void emitParameterGroupImpl(IRGlobalParam* varDecl, IRUniformParameterGroupType* type) SLANG_OVERRIDE;
     virtual void emitEntryPointAttributesImpl(IRFunc* irFunc, IREntryPointDecoration* entryPointDecor) SLANG_OVERRIDE;
 
diff --git a/source/slang/slang-emit-glsl.cpp b/source/slang/slang-emit-glsl.cpp
index b6c3c0d67..7cf478c36 100644
--- a/source/slang/slang-emit-glsl.cpp
+++ b/source/slang/slang-emit-glsl.cpp
@@ -751,6 +751,11 @@ bool GLSLSourceEmitter::_emitGLSLLayoutQualifierWithBindingKinds(LayoutResourceK
             m_writer->emit("layout(shaderRecordEXT)\n");
             break;
 
+        case LayoutResourceKind::InputAttachmentIndex:
+            m_writer->emit("layout(input_attachment_index = ");
+            m_writer->emit(index);
+            m_writer->emit(")\n");
+            break;
     }
     return true;
 }
@@ -1338,7 +1343,7 @@ void GLSLSourceEmitter::_emitGLSLPerVertexVaryingFragmentInput(IRGlobalParam* pa
 
     emitSemantics(param, false);
 
-    emitLayoutSemantics(param);
+    emitLayoutSemantics(param, "register");
 
     m_writer->emit(";\n\n");
 }
@@ -2825,16 +2830,6 @@ void GLSLSourceEmitter::emitVarDecorationsImpl(IRInst* varDecl)
         break;
     }
 
-    // non raytracing decorations
-    for (auto decoration : varDecl->getDecorations())
-    {        
-        if (auto glslInputAttachment = as<IRGLSLInputAttachmentIndexDecoration>(decoration))
-        {
-            m_writer->emit(toSlice("layout(input_attachment_index = "));
-            m_writer->emit(glslInputAttachment->getIndex()->getValue());
-            m_writer->emit(toSlice(")\n"));
-        }
-    }
 }
 
 void GLSLSourceEmitter::emitMatrixLayoutModifiersImpl(IRVarLayout* layout)
diff --git a/source/slang/slang-emit-hlsl.cpp b/source/slang/slang-emit-hlsl.cpp
index 04f5bd643..4d3830969 100644
--- a/source/slang/slang-emit-hlsl.cpp
+++ b/source/slang/slang-emit-hlsl.cpp
@@ -93,6 +93,13 @@ void HLSLSourceEmitter::_emitHLSLRegisterSemantic(LayoutResourceKind kind, EmitV
         break;
 
         case LayoutResourceKind::InputAttachmentIndex:
+        {
+            m_writer->emit("[[vk::input_attachment_index("); 
+            m_writer->emit(index);
+            m_writer->emit(")]]");
+        }
+        break;
+
         case LayoutResourceKind::RegisterSpace:
         case LayoutResourceKind::GenericResource:
         case LayoutResourceKind::ExistentialTypeParam:
@@ -141,7 +148,7 @@ void HLSLSourceEmitter::_emitHLSLRegisterSemantic(LayoutResourceKind kind, EmitV
     }
 }
 
-void HLSLSourceEmitter::_emitHLSLRegisterSemantics(EmitVarChain* chain, IRInst* inst, char const* uniformSemanticSpelling)
+void HLSLSourceEmitter::_emitHLSLRegisterSemantics(EmitVarChain* chain, IRInst* inst, char const* uniformSemanticSpelling, EmitLayoutSemanticOption layoutSemanticOption)
 {
     if (!chain) return;
 
@@ -158,17 +165,20 @@ void HLSLSourceEmitter::_emitHLSLRegisterSemantics(EmitVarChain* chain, IRInst*
 
     for (auto rr : layout->getOffsetAttrs())
     {
+        if (layoutSemanticOption == EmitLayoutSemanticOption::kPreType
+            && rr->getResourceKind() != LayoutResourceKind::InputAttachmentIndex)
+            continue;
         _emitHLSLRegisterSemantic(rr->getResourceKind(), chain, inst, uniformSemanticSpelling);
     }
 }
 
-void HLSLSourceEmitter::_emitHLSLRegisterSemantics(IRVarLayout* varLayout, IRInst* inst, char const* uniformSemanticSpelling)
+void HLSLSourceEmitter::_emitHLSLRegisterSemantics(IRVarLayout* varLayout, IRInst* inst, char const* uniformSemanticSpelling, EmitLayoutSemanticOption layoutSemanticOption)
 {
     if (!varLayout)
         return;
 
     EmitVarChain chain(varLayout);
-    _emitHLSLRegisterSemantics(&chain, inst, uniformSemanticSpelling);
+    _emitHLSLRegisterSemantics(&chain, inst, uniformSemanticSpelling, layoutSemanticOption);
 }
 
 void HLSLSourceEmitter::_emitHLSLParameterGroupFieldLayoutSemantics(EmitVarChain* chain)
@@ -220,7 +230,7 @@ void HLSLSourceEmitter::_emitHLSLParameterGroup(IRGlobalParam* varDecl, IRUnifor
         typeLayout = parameterGroupTypeLayout->getElementVarLayout()->getTypeLayout();
     }
 
-    _emitHLSLRegisterSemantic(layoutResourceKind, &containerChain, varDecl);
+    _emitHLSLRegisterSemantic(layoutResourceKind, &containerChain, varDecl, "register");
 
     auto elementType = type->getElementType();
     if (shouldForceUnpackConstantBufferElements(type) || hasExplicitConstantBufferOffset(type))
@@ -320,12 +330,12 @@ void HLSLSourceEmitter::_emitHLSLSubpassInputType(IRSubpassInputType* subpassTyp
     m_writer->emit(">");
 }
 
-void HLSLSourceEmitter::emitLayoutSemanticsImpl(IRInst* inst, char const* uniformSemanticSpelling)
+void HLSLSourceEmitter::emitLayoutSemanticsImpl(IRInst* inst, char const* uniformSemanticSpelling, EmitLayoutSemanticOption layoutSemanticOption)
 {
     auto layout = getVarLayout(inst); 
     if (layout)
     {
-        _emitHLSLRegisterSemantics(layout, inst, uniformSemanticSpelling);
+        _emitHLSLRegisterSemantics(layout, inst, uniformSemanticSpelling, layoutSemanticOption);
     }
 }
 
@@ -1281,13 +1291,6 @@ void HLSLSourceEmitter::emitVarDecorationsImpl(IRInst* varDecl)
 {
     for(auto decoration : varDecl->getDecorations())
     {
-        if(auto glslInputAttachmentIndex = as<IRGLSLInputAttachmentIndexDecoration>(decoration))
-        {
-            m_writer->emit("[[vk::input_attachment_index(");
-            m_writer->emit(glslInputAttachmentIndex->getIndex()->getValue());
-            m_writer->emit(")]]\n");
-            continue;
-        }
         if (auto collection = as<IRMemoryQualifierSetDecoration>(decoration))
         {
             auto flags = collection->getMemoryQualifierBit();
diff --git a/source/slang/slang-emit-hlsl.h b/source/slang/slang-emit-hlsl.h
index 30f38b415..abc673a3d 100644
--- a/source/slang/slang-emit-hlsl.h
+++ b/source/slang/slang-emit-hlsl.h
@@ -29,7 +29,7 @@ public:
 protected:
     RefPtr<HLSLExtensionTracker> m_extensionTracker;
 
-    virtual void emitLayoutSemanticsImpl(IRInst* inst, char const* uniformSemanticSpelling) SLANG_OVERRIDE;
+    virtual void emitLayoutSemanticsImpl(IRInst* inst, char const* uniformSemanticSpelling, EmitLayoutSemanticOption layoutSemanticOption) SLANG_OVERRIDE;
     virtual void emitParameterGroupImpl(IRGlobalParam* varDecl, IRUniformParameterGroupType* type) SLANG_OVERRIDE;
     virtual void emitEntryPointAttributesImpl(IRFunc* irFunc, IREntryPointDecoration* entryPointDecor) SLANG_OVERRIDE;
     
@@ -66,11 +66,11 @@ protected:
 
         // Emit a single `register` semantic, as appropriate for a given resource-type-specific layout info
         // Keyword to use in the uniform case (`register` for globals, `packoffset` inside a `cbuffer`)
-    void _emitHLSLRegisterSemantic(LayoutResourceKind kind, EmitVarChain* chain, IRInst* inst, char const* uniformSemanticSpelling = "register");
+    void _emitHLSLRegisterSemantic(LayoutResourceKind kind, EmitVarChain* chain, IRInst* inst, char const* uniformSemanticSpelling);
 
         // Emit all the `register` semantics that are appropriate for a particular variable layout
-    void _emitHLSLRegisterSemantics(EmitVarChain* chain, IRInst* inst, char const* uniformSemanticSpelling = "register");
-    void _emitHLSLRegisterSemantics(IRVarLayout* varLayout, IRInst* inst, char const* uniformSemanticSpelling = "register");
+    void _emitHLSLRegisterSemantics(EmitVarChain* chain, IRInst* inst, char const* uniformSemanticSpelling, EmitLayoutSemanticOption layoutSemanticOption);
+    void _emitHLSLRegisterSemantics(IRVarLayout* varLayout, IRInst* inst, char const* uniformSemanticSpelling, EmitLayoutSemanticOption layoutSemanticOption);
 
     void _emitHLSLParameterGroupFieldLayoutSemantics(EmitVarChain* chain);
     void _emitHLSLParameterGroupFieldLayoutSemantics(IRVarLayout* fieldLayout, EmitVarChain* inChain);
diff --git a/source/slang/slang-emit-spirv.cpp b/source/slang/slang-emit-spirv.cpp
index 51a71d65c..1a4d80ae1 100644
--- a/source/slang/slang-emit-spirv.cpp
+++ b/source/slang/slang-emit-spirv.cpp
@@ -2230,6 +2230,16 @@ struct SPIRVEmitContext
                     isDescirptorSetDecorated = true;
                 }
                 break;
+            case LayoutResourceKind::InputAttachmentIndex:
+                {
+                    emitOpDecorateInputAttachmentIndex(
+                        getSection(SpvLogicalSectionID::Annotations),
+                        nullptr,
+                        varInst,
+                        SpvLiteralInteger::from32((int32_t)index)
+                    );
+                }
+                break;
             default:
                 break;
             }
@@ -3576,17 +3586,6 @@ struct SPIRVEmitContext
                 );
             }
             break;
-        case kIROp_GLSLInputAttachmentIndexDecoration:
-            {
-                const auto c = cast<IRGLSLInputAttachmentIndexDecoration>(decoration);
-                emitOpDecorateInputAttachmentIndex(
-                    getSection(SpvLogicalSectionID::Annotations),
-                    decoration,
-                    dstID,
-                    SpvLiteralInteger::from32(int32_t(c->getIndex()->getValue()))
-                );
-            }
-            break;
 
         case kIROp_VulkanHitAttributesDecoration:
         case kIROp_VulkanCallablePayloadDecoration:
diff --git a/source/slang/slang-ir-inst-defs.h b/source/slang/slang-ir-inst-defs.h
index 19117c00e..3132536e3 100644
--- a/source/slang/slang-ir-inst-defs.h
+++ b/source/slang/slang-ir-inst-defs.h
@@ -893,7 +893,6 @@ INST_RANGE(BindingQuery, GetRegisterIndex, GetRegisterSpace)
     INST(GlobalOutputDecoration, output, 0, 0)
     INST(GlobalInputDecoration, output, 0, 0)
     INST(GLSLLocationDecoration, glslLocation, 1, 0)
-    INST(GLSLInputAttachmentIndexDecoration, glslInputAttachmentIndex, 1, 0)
     INST(GLSLOffsetDecoration, glslOffset, 1, 0)
     INST(PayloadDecoration, payload, 0, 0)
 
diff --git a/source/slang/slang-ir-insts.h b/source/slang/slang-ir-insts.h
index a63cc5c22..fb9a9613a 100644
--- a/source/slang/slang-ir-insts.h
+++ b/source/slang/slang-ir-insts.h
@@ -437,11 +437,6 @@ struct IRGLSLLocationDecoration : IRDecoration
     IRIntLit* getLocation() { return cast<IRIntLit>(getOperand(0)); }
 };
 
-struct IRGLSLInputAttachmentIndexDecoration : IRDecoration
-{
-    IR_LEAF_ISA(GLSLInputAttachmentIndexDecoration)
-    IRIntLit* getIndex() { return cast<IRIntLit>(getOperand(0)); }
-};
 
 struct IRGLSLOffsetDecoration : IRDecoration
 {
diff --git a/source/slang/slang-lower-to-ir.cpp b/source/slang/slang-lower-to-ir.cpp
index cc4704fe9..c946072f9 100644
--- a/source/slang/slang-lower-to-ir.cpp
+++ b/source/slang/slang-lower-to-ir.cpp
@@ -2212,16 +2212,6 @@ void addVarDecorations(
             builder->addDecoration(inst, kIROp_GLSLLocationDecoration,
                 builder->getIntValue(builder->getIntType(), stringToInt(glslLocationMod->valToken.getContent())));
         }
-        else if (auto glslInputAttachmentMod = as<GLSLInputAttachmentIndexLayoutModifier>(mod))
-        {
-            auto subpassType = as<IRSubpassInputType>(inst->getDataType());
-
-            if (!subpassType)
-                context->getSink()->diagnose(inst, Diagnostics::InputAttachmentIndexOnlyAllowedOnSubpass);
-
-            builder->addDecoration(inst, kIROp_GLSLInputAttachmentIndexDecoration,
-                builder->getIntValue(builder->getIntType(), stringToInt(glslInputAttachmentMod->valToken.getContent())));
-        }
         else if (auto glslOffsetMod = as<GLSLOffsetLayoutAttribute>(mod))
         {
             builder->addDecoration(inst, kIROp_GLSLOffsetDecoration,
diff --git a/source/slang/slang-parameter-binding.cpp b/source/slang/slang-parameter-binding.cpp
index d76dda4e1..6a1080b0e 100644
--- a/source/slang/slang-parameter-binding.cpp
+++ b/source/slang/slang-parameter-binding.cpp
@@ -996,6 +996,16 @@ static void addExplicitParameterBindings_HLSL(
 
     // If the declaration has explicit binding modifiers, then
     // here is where we want to extract and apply them...
+    if (auto inputAttachmentIndexLayoutAttribute = varDecl.getDecl()->findModifier<GLSLInputAttachmentIndexLayoutAttribute>())
+    {
+        LayoutSemanticInfo semanticInfo;
+        semanticInfo.index = (UInt)inputAttachmentIndexLayoutAttribute->location;
+        semanticInfo.space = 0;
+        semanticInfo.kind = LayoutResourceKind::InputAttachmentIndex;
+
+        if (auto varDeclBase = varDecl.as<VarDeclBase>())
+            addExplicitParameterBinding(context, parameterInfo, varDeclBase.getDecl(), semanticInfo, 1);
+    }
 
     // Look for HLSL `register` or `packoffset` semantics.
     for (auto semantic : varDecl.getDecl()->getModifiersOfType<HLSLLayoutSemantic>())
@@ -1065,82 +1075,96 @@ static void addExplicitParameterBindings_GLSL(
     // the index/offset/etc.
     //
 
-    TypeLayout::ResourceInfo* resInfo = nullptr;
-    TypeLayout::ResourceInfo* foundResInfo = nullptr;
-
-    LayoutSemanticInfo semanticInfo;
-    semanticInfo.index = 0;
-    semanticInfo.space = 0;
+    enum 
+    {
+        kResInfo = 0,
+        kSubpassResInfo,
+        kMaxResCount,
+    };
 
-    LayoutSemanticInfo subpassSemanticInfo;
-    bool foundBinding = false;
-    bool foundSubpass = false;
+    TypeLayout::ResourceInfo* foundResInfo = nullptr;
+    struct ResAndSemanticInfo
+    {
+        TypeLayout::ResourceInfo* resInfo = nullptr;
+        LayoutSemanticInfo semanticInfo;
+        ResAndSemanticInfo()
+        {
+            semanticInfo.index = 0;
+            semanticInfo.space = 0;
+        }
+    };
+    ResAndSemanticInfo info[kMaxResCount] = {};
+    
+    if (auto foundInputAttachmentIndex = typeLayout->FindResourceInfo(LayoutResourceKind::InputAttachmentIndex))
+    {
+        foundResInfo = foundInputAttachmentIndex;
+        // Try to find `input_attachment_index`
+        if (auto glslAttachmentIndexAttr = varDecl.getDecl()->findModifier<GLSLInputAttachmentIndexLayoutAttribute>())
+        {
+            info[kSubpassResInfo].resInfo = foundResInfo;
+            // Subpass fills semantic info of a descriptor and subpass
+            info[kSubpassResInfo].semanticInfo.index = (UInt)glslAttachmentIndexAttr->location;
+            info[kSubpassResInfo].semanticInfo.space = 0;
+        }
+    }
 
-    if( (foundResInfo = typeLayout->FindResourceInfo(LayoutResourceKind::DescriptorTableSlot)) != nullptr )
+    if(auto foundDescriptorTableSlot = typeLayout->FindResourceInfo(LayoutResourceKind::DescriptorTableSlot))
     {
-        for (auto dec : varDecl.getDecl()->modifiers)
+        foundResInfo = foundDescriptorTableSlot;
+        // Try to find `binding` and `set`
+        if (auto glslBindingAttr = varDecl.getDecl()->findModifier<GLSLBindingAttribute>())
         {
-            // Try to find `binding` and `set`
-            if (auto glslBindingAttr = as<GLSLBindingAttribute>(dec))
-            {
-                resInfo = foundResInfo;
-                semanticInfo.index = glslBindingAttr->binding;
-                semanticInfo.space = glslBindingAttr->set;
-                foundBinding = true;
-                if (foundSubpass) 
-                    break;
-            }
-            // Try to find `input_attachment_index`
-            else if (auto glslAttachmentIndexAttr = as<GLSLInputAttachmentIndexLayoutModifier>(dec))
-            {
-                // Subpass fills semantic info of a descriptor & subpass
-                subpassSemanticInfo.index = stringToInt(glslAttachmentIndexAttr->valToken.getContent());
-                subpassSemanticInfo.space = 0;
-                subpassSemanticInfo.kind = LayoutResourceKind::InputAttachmentIndex;
-                foundSubpass = true;
-                if (foundBinding) 
-                    break;
-            }
+            info[kResInfo].resInfo = foundResInfo;
+            info[kResInfo].semanticInfo.index = glslBindingAttr->binding;
+            info[kResInfo].semanticInfo.space = glslBindingAttr->set;
         }
     }
-    else if( (foundResInfo = typeLayout->FindResourceInfo(LayoutResourceKind::SubElementRegisterSpace)) != nullptr )
+    else if(auto foundSubElementRegisterSpace = typeLayout->FindResourceInfo(LayoutResourceKind::SubElementRegisterSpace))
     {
+        foundResInfo = foundSubElementRegisterSpace;
         // Try to find `set`
         if (auto attr = varDecl.getDecl()->findModifier<GLSLBindingAttribute>())
         {
-            resInfo = foundResInfo;
+            info[kResInfo].resInfo = foundResInfo;
             if (attr->binding != 0)
             {
                 getSink(context)->diagnose(attr, Diagnostics::wholeSpaceParameterRequiresZeroBinding, varDecl.getName(), attr->binding);
             }
-            semanticInfo.index = attr->set;
-            semanticInfo.space = 0;
+            info[kResInfo].semanticInfo.index = attr->set;
+            info[kResInfo].semanticInfo.space = 0;
         }
     }
-    else if( (resInfo = typeLayout->FindResourceInfo(LayoutResourceKind::SpecializationConstant)) != nullptr )
+    else if(auto foundSpecializationConstant = typeLayout->FindResourceInfo(LayoutResourceKind::SpecializationConstant))
     {
+        info[kResInfo].resInfo = foundSpecializationConstant;
         DeclRef<Decl> varDecl2(varDecl);
 
         // Try to find `constant_id` binding
-        if(!findLayoutArg<GLSLConstantIDLayoutModifier>(varDecl2, &semanticInfo.index))
+        if(!findLayoutArg<GLSLConstantIDLayoutModifier>(varDecl2, &info[kResInfo].semanticInfo.index))
             return;
     }
 
-    // if we found resInfo, we add the explicit binding
-    if (resInfo)
+
+    auto varDeclBase = as<VarDeclBase>(varDecl);
+    bool hasABinding = false;
+    for (int i = 0; i < kMaxResCount; i++)
     {
-        auto kind = resInfo->kind;
-        auto count = resInfo->count;
+        auto* resInfoItem = info[i].resInfo;
+        auto& semanticInfo = info[i].semanticInfo;
+        if (!resInfoItem)
+            continue;
+
+        auto kind = resInfoItem->kind;
+        auto count = resInfoItem->count;
         semanticInfo.kind = kind;
+        hasABinding = true;
+        if(!varDeclBase)
+            break;
 
-        if (auto varDeclBase = varDecl.as<VarDeclBase>())
-        {
-            addExplicitParameterBinding(context, parameterInfo, varDeclBase.getDecl(), semanticInfo, count);
-            if (foundSubpass)
-                addExplicitParameterBinding(context, parameterInfo, varDeclBase.getDecl(), subpassSemanticInfo, count);
-        }
-        return;
+        addExplicitParameterBinding(context, parameterInfo, varDeclBase.getDecl(), semanticInfo, count);
     }
+    if(hasABinding)
+        return;
 
     auto hlslToVulkanLayoutOptions = context->getTargetProgram()->getHLSLToVulkanLayoutOptions();
     bool warnedMissingVulkanLayoutModifier = false;
@@ -1196,7 +1220,7 @@ static void addExplicitParameterBindings_GLSL(
 
     // We use the HLSL binding directly (even though this notionally for GLSL/Vulkan)
     // We'll do the shifting at later later point in _maybeApplyHLSLToVulkanShifts
-    resInfo = typeLayout->findOrAddResourceInfo(hlslInfo.kind);
+    info[kResInfo].resInfo = typeLayout->findOrAddResourceInfo(hlslInfo.kind);
 
     if (warnedMissingVulkanLayoutModifier)
     {
@@ -1205,8 +1229,8 @@ static void addExplicitParameterBindings_GLSL(
         if(!hlslToVulkanLayoutOptions
             || hlslToVulkanLayoutOptions->getKindShiftEnabledFlags() == HLSLToVulkanLayoutOptions::KindFlag::None)
         {
-            resInfo->kind = LayoutResourceKind::DescriptorTableSlot;
-            resInfo->count = 1;
+            info[kResInfo].resInfo->kind = LayoutResourceKind::DescriptorTableSlot;
+            info[kResInfo].resInfo->count = 1;
         }
         else
         {
@@ -1214,12 +1238,12 @@ static void addExplicitParameterBindings_GLSL(
         }
     }
 
-    semanticInfo.kind = resInfo->kind;
-    semanticInfo.index = UInt(hlslInfo.index);
-    semanticInfo.space = UInt(hlslInfo.space);
-    const LayoutSize count = resInfo->count;
+    info[kResInfo].semanticInfo.kind = info[kResInfo].resInfo->kind;
+    info[kResInfo].semanticInfo.index = UInt(hlslInfo.index);
+    info[kResInfo].semanticInfo.space = UInt(hlslInfo.space);
+    const LayoutSize count = info[kResInfo].resInfo->count;
 
-    addExplicitParameterBinding(context, parameterInfo, as<VarDeclBase>(varDecl.getDecl()), semanticInfo, count);
+    addExplicitParameterBinding(context, parameterInfo, as<VarDeclBase>(varDecl.getDecl()), info[kResInfo].semanticInfo, count);
 }
 
 // Given a single parameter, collect whatever information we have on
diff --git a/source/slang/slang-parser.cpp b/source/slang/slang-parser.cpp
index 3d9f1c199..e6913c6c0 100644
--- a/source/slang/slang-parser.cpp
+++ b/source/slang/slang-parser.cpp
@@ -8061,7 +8061,7 @@ namespace Slang
         GLSLLayoutLocalSizeAttribute* numThreadsAttrib = nullptr;
         GLSLLayoutDerivativeGroupQuadAttribute* derivativeGroupQuadAttrib = nullptr;
         GLSLLayoutDerivativeGroupLinearAttribute* derivativeGroupLinearAttrib = nullptr; 
-
+        GLSLInputAttachmentIndexLayoutAttribute* inputAttachmentIndexLayoutAttribute = nullptr;
         ImageFormat format;
 
         listBuilder.add(parser->astBuilder->create<GLSLLayoutModifierGroupBegin>());
@@ -8115,6 +8115,17 @@ namespace Slang
             {
                 derivativeGroupLinearAttrib = parser->astBuilder->create<GLSLLayoutDerivativeGroupLinearAttribute>();
             }
+            else if (nameText == "input_attachment_index")
+            {
+                inputAttachmentIndexLayoutAttribute = parser->astBuilder->create<GLSLInputAttachmentIndexLayoutAttribute>();
+                if (AdvanceIf(parser, TokenType::OpAssign))
+                {
+                    auto token = parser->ReadToken(TokenType::IntegerLiteral);
+                    auto intVal = getIntegerLiteralValue(token);
+                    inputAttachmentIndexLayoutAttribute->location = intVal;
+                }
+
+            }
             else if (nameText == "binding" ||
                 nameText == "set")
             {
@@ -8165,7 +8176,6 @@ namespace Slang
                 CASE(scalar, GLSLScalarModifier)
                 CASE(offset, GLSLOffsetLayoutAttribute)
                 CASE(location, GLSLLocationLayoutModifier) 
-                CASE(input_attachment_index, GLSLInputAttachmentIndexLayoutModifier)
                 {
                     modifier = parser->astBuilder->create<GLSLUnparsedLayoutModifier>();
                 }
@@ -8227,6 +8237,8 @@ namespace Slang
             listBuilder.add(derivativeGroupQuadAttrib);
         if(derivativeGroupLinearAttrib)
             listBuilder.add(derivativeGroupLinearAttrib);
+        if(inputAttachmentIndexLayoutAttribute)
+            listBuilder.add(inputAttachmentIndexLayoutAttribute);
 
         listBuilder.add(parser->astBuilder->create<GLSLLayoutModifierGroupEnd>());
 
diff --git a/source/slang/slang-type-layout.cpp b/source/slang/slang-type-layout.cpp
index 22aa3f304..293dce7c6 100644
--- a/source/slang/slang-type-layout.cpp
+++ b/source/slang/slang-type-layout.cpp
@@ -722,6 +722,9 @@ static LayoutResourceKind _getHLSLLayoutResourceKind(ShaderParameterKind kind)
 {
     switch (kind)
     {
+        case ShaderParameterKind::SubpassInput:
+            return LayoutResourceKind::InputAttachmentIndex;
+
         case ShaderParameterKind::ConstantBuffer:
             return LayoutResourceKind::ConstantBuffer;
 
@@ -778,6 +781,13 @@ struct GLSLObjectLayoutRulesImpl : ObjectLayoutRulesImpl
             }
         }
 
+        switch (kind)
+        {
+        case ShaderParameterKind::SubpassInput:
+            return SimpleLayoutInfo(LayoutResourceKind::InputAttachmentIndex, slotCount);
+        default:
+            break;
+        }
         return SimpleLayoutInfo(LayoutResourceKind::DescriptorTableSlot, slotCount);
     }
 };
@@ -4089,6 +4099,17 @@ static TypeLayoutResult _createTypeLayout(
             type,
             rules);
     }
+    else if (as<SubpassInputType>(type))
+    {
+        // SubpassInputType fills 2 slots, 'shader resource' and 'input_attachment_index'
+        auto objLayout1 = rules->GetObjectLayout(ShaderParameterKind::Texture, context.objectLayoutOptions);
+        auto objLayout2 = rules->GetObjectLayout(ShaderParameterKind::SubpassInput, context.objectLayoutOptions);
+        objLayout1.layoutInfos.add(objLayout2.layoutInfos.getFirst());
+        return createSimpleTypeLayout(
+            objLayout1,
+            type,
+            rules);
+    }
     else if (auto textureType = as<TextureType>(type))
     {
         // TODO: the logic here should really be defined by the rules,
diff --git a/tests/glsl-intrinsic/subpass-input/input-attachment-index-use-error.slang b/tests/glsl-intrinsic/subpass-input/input-attachment-index-use-error.slang
deleted file mode 100644
index 889a4e205..000000000
--- a/tests/glsl-intrinsic/subpass-input/input-attachment-index-use-error.slang
+++ /dev/null
@@ -1,11 +0,0 @@
-//TEST:SIMPLE(filecheck=CHECK): -target glsl -stage fragment -entry main -allow-glsl
-#version 450
-
-// CHECK: error 31207
-layout (input_attachment_index = 1, set = 0, binding = 1) uniform vec3 image;
-
-layout (location = 0) out vec4 outColor;
-
-void main() {
-    outColor = vec4(0);
-}
\ No newline at end of file
diff --git a/tests/glsl-intrinsic/subpass-input/subpass-input-hlsl.slang b/tests/glsl-intrinsic/subpass-input/subpass-input-hlsl.slang
new file mode 100644
index 000000000..0b8e4896f
--- /dev/null
+++ b/tests/glsl-intrinsic/subpass-input/subpass-input-hlsl.slang
@@ -0,0 +1,32 @@
+//TEST:SIMPLE(filecheck=CHECK_GLSL): -target glsl -stage fragment -entry main -allow-glsl
+//TEST:SIMPLE(filecheck=CHECK_SPV): -target spirv -emit-spirv-directly -stage fragment -entry main -allow-glsl
+//TEST:SIMPLE(filecheck=CHECK_HLSL): -target hlsl -stage fragment -entry main -allow-glsl
+
+// CHECK_SPV-DAG: OpEntryPoint
+// CHECK_SPV-DAG: InputAttachmentIndex 3
+// CHECK_SPV-DAG: InputAttachmentIndex
+
+// CHECK_GLSL-DAG: void main()
+// CHECK_GLSL-DAG: input_attachment_index = 3
+// CHECK_GLSL-DAG: input_attachment_index
+
+// CHECK_HLSL-DAG: main()
+// CHECK_HLSL-DAG: [vk::input_attachment_index(3)]
+// CHECK_HLSL-DAG: vk::input_attachment_index
+[[vk::input_attachment_index(3)]] SubpassInput subpassHLSL1;
+SubpassInput subpassHLSL2;
+
+RWTexture2D<float4> t;
+
+layout (location = 0) out vec4 outColor;
+
+void main() {
+// CHECK_SPV-COUNT-2: OpImageRead
+// CHECK_GLSL-COUNT-2: subpassLoad
+// CHECK_HLSL-COUNT-2: SubpassLoad
+    outColor = vec4(true
+        && subpassHLSL1.SubpassLoad() == vec4(1)
+        && subpassHLSL2.SubpassLoad() == vec4(1)
+        && t.Load(int2(0,0)) != float4(0,0,0,0)
+    );
+}
\ No newline at end of file