fixup global generic parameters

1. simplify RoundUpToAlignment()
2. add new a render-compute test case to cover the situation where the entry-point interface (parameter/return types of an entry-point function) is dependent on the global generic type.
3. initial fixes to get this test case to compile (but is not producing correct HLSL output yet)

9 files changed, 172 insertions, 25 deletions

diff --git a/source/slang/ir.cpp b/source/slang/ir.cpp
index 2d3127a61..f5f52e08a 100644
--- a/source/slang/ir.cpp
+++ b/source/slang/ir.cpp
@@ -3103,10 +3103,22 @@ namespace Slang
     IRGlobalVar* cloneGlobalVar(IRSpecContext* context, IRGlobalVar* originalVar);
     IRFunc* cloneFunc(IRSpecContext* context, IRFunc* originalFunc);
     IRWitnessTable* cloneWitnessTable(IRSpecContext* context, IRWitnessTable* originalVar);
+    RefPtr<Substitutions> cloneSubstitutions(
+        IRSpecContext*  context,
+        Substitutions*  subst);
 
     RefPtr<Type> IRSpecContext::maybeCloneType(Type* originalType)
     {
-        return originalType->Substitute(subst).As<Type>();
+        auto rsType = originalType->Substitute(subst).As<Type>();
+        if (auto declRefType = rsType.As<DeclRefType>())
+        {
+            if (subst)
+            {
+                auto newSubst = cloneSubstitutions(this, subst);
+                insertSubstAtBottom(declRefType->declRef.substitutions, newSubst);
+            }
+        }
+        return rsType;
     }
 
     IRValue* IRSpecContext::maybeCloneValue(IRValue* originalValue)
@@ -3243,6 +3255,15 @@ namespace Slang
             newSubst->outer = cloneSubstitutions(context, subst->outer);
             return newSubst;
         }
+        else if (auto genTypeSubst = dynamic_cast<GlobalGenericParamSubstitution*>(subst))
+        {
+            RefPtr<GlobalGenericParamSubstitution> newSubst = new GlobalGenericParamSubstitution();
+            newSubst->actualType = genTypeSubst->actualType;
+            newSubst->paramDecl = genTypeSubst->paramDecl;
+            newSubst->witnessTables = genTypeSubst->witnessTables;
+            newSubst->outer = cloneSubstitutions(context, subst->outer);
+            return newSubst;
+        }
         else
             SLANG_UNREACHABLE("unimplemented cloneSubstitution");
         UNREACHABLE_RETURN(nullptr);
diff --git a/source/slang/parameter-binding.cpp b/source/slang/parameter-binding.cpp
index 836ed254f..0daa2abc7 100644
--- a/source/slang/parameter-binding.cpp
+++ b/source/slang/parameter-binding.cpp
@@ -1425,6 +1425,16 @@ static RefPtr<TypeLayout> processEntryPointParameter(
 
             return structLayout;
         }
+        else if (auto globalGenericParam = declRef.As<GlobalGenericParamDecl>())
+        {
+            auto genParamTypeLayout = new GenericParamTypeLayout();
+            // we should have already populated ProgramLayout::genericEntryPointParams list at this point,
+            // so we can find the index of this generic param decl in the list
+            genParamTypeLayout->type = type;
+            genParamTypeLayout->paramIndex = findGenericParam(context->shared->programLayout->globalGenericParams, globalGenericParam.getDecl());
+            genParamTypeLayout->findOrAddResourceInfo(LayoutResourceKind::GenericResource)->count++;
+            return genParamTypeLayout;
+        }
         else
         {
             SLANG_UNEXPECTED("unhandled type kind");
@@ -1442,7 +1452,8 @@ static RefPtr<TypeLayout> processEntryPointParameter(
 
 static void collectEntryPointParameters(
     ParameterBindingContext*        context,
-    EntryPointRequest*              entryPoint)
+    EntryPointRequest*              entryPoint,
+    Substitutions*                  typeSubst)
 {
     FuncDecl* entryPointFuncDecl = entryPoint->decl;
     if (!entryPointFuncDecl)
@@ -1507,7 +1518,7 @@ static void collectEntryPointParameters(
         auto paramTypeLayout = processEntryPointParameterWithPossibleSemantic(
             context,
             paramDecl.Ptr(),
-            paramDecl->type.type,
+            paramDecl->type.type->Substitute(typeSubst).As<Type>(),
             state,
             paramVarLayout);
 
@@ -1539,7 +1550,7 @@ static void collectEntryPointParameters(
         auto resultTypeLayout = processEntryPointParameterWithPossibleSemantic(
             context,
             entryPointFuncDecl,
-            resultType,
+            resultType->Substitute(typeSubst).As<Type>(),
             state,
             resultLayout);
 
@@ -1632,7 +1643,7 @@ static void collectParameters(
         for( auto& entryPoint : translationUnit->entryPoints )
         {
             context->stage = entryPoint->profile.GetStage();
-            collectEntryPointParameters(context, entryPoint.Ptr());
+            collectEntryPointParameters(context, entryPoint.Ptr(), nullptr);
         }
     }
 
@@ -1891,13 +1902,7 @@ RefPtr<ProgramLayout> specializeProgramLayout(
     newProgramLayout = new ProgramLayout();
     newProgramLayout->bindingForHackSampler = programLayout->bindingForHackSampler;
     newProgramLayout->hackSamplerVar = programLayout->hackSamplerVar;
-    for (auto & entryPoint : programLayout->entryPoints)
-    {
-        RefPtr<EntryPointLayout> newEntryPoint = new EntryPointLayout(*entryPoint);
-        // TODO: for now just copy existing entry point layouts, but we eventually need to
-        // specialize these as well...
-        newProgramLayout->entryPoints.Add(newEntryPoint);
-    }
+    newProgramLayout->globalGenericParams = programLayout->globalGenericParams;
 
     List<RefPtr<TypeLayout>> paramTypeLayouts;
     auto globalStructLayout = getGlobalStructLayout(programLayout);
@@ -1919,7 +1924,7 @@ RefPtr<ProgramLayout> specializeProgramLayout(
     SharedParameterBindingContext sharedContext;
     sharedContext.compileRequest = targetReq->compileRequest;
     sharedContext.defaultLayoutRules = layoutContext.getRulesFamily();
-    sharedContext.programLayout = programLayout;
+    sharedContext.programLayout = newProgramLayout;
 
     // Create a sub-context to collect parameters that get
     // declared into the global scope
@@ -1928,6 +1933,15 @@ RefPtr<ProgramLayout> specializeProgramLayout(
     context.translationUnit = nullptr;
     context.layoutContext = layoutContext;
     
+    
+    for (auto & translationUnit : targetReq->compileRequest->translationUnits)
+    {
+        for (auto & entryPoint : translationUnit->entryPoints)
+        {
+            collectEntryPointParameters(&context, entryPoint, typeSubst);
+        }
+    }
+
     auto constantBufferRules = context.getRulesFamily()->getConstantBufferRules();
     structLayout->rules = constantBufferRules;
 
diff --git a/source/slang/syntax.cpp b/source/slang/syntax.cpp
index e43dd9074..badfaea4f 100644
--- a/source/slang/syntax.cpp
+++ b/source/slang/syntax.cpp
@@ -1709,7 +1709,22 @@ void Type::accept(IValVisitor* visitor, void* extra)
         return sb.ProduceString();
     }
 
-
+    void insertSubstAtBottom(RefPtr<Substitutions> & substHead, RefPtr<Substitutions> substToInsert)
+    {
+        if (!substHead)
+        {
+            substHead = substToInsert;
+            return;
+        }
+        auto subst = substHead;
+        RefPtr<Substitutions> lastSubst = subst;
+        while (subst->outer)
+        {
+            lastSubst = subst;
+            subst = subst->outer;
+        }
+        lastSubst->outer = substToInsert;
+    }
 
     void insertSubstAtTop(DeclRefBase & declRef, RefPtr<Substitutions> substToInsert)
     {
diff --git a/source/slang/syntax.h b/source/slang/syntax.h
index b4d550ef5..f3690d9ae 100644
--- a/source/slang/syntax.h
+++ b/source/slang/syntax.h
@@ -1156,6 +1156,7 @@ namespace Slang
         Session* session,
         Decl*   decl);
 
+    void insertSubstAtBottom(RefPtr<Substitutions> & substHead, RefPtr<Substitutions> substToInsert);
     RefPtr<ThisTypeSubstitution> getNewThisTypeSubst(DeclRefBase & declRef);
     RefPtr<ThisTypeSubstitution> getThisTypeSubst(DeclRefBase & declRef, bool insertSubstEntry);
     void removeSubstitution(DeclRefBase & declRef, RefPtr<Substitutions> subst);
diff --git a/source/slang/type-layout.h b/source/slang/type-layout.h
index 4ce6dc355..07530bdfc 100644
--- a/source/slang/type-layout.h
+++ b/source/slang/type-layout.h
@@ -676,7 +676,7 @@ createStructuredBufferTypeLayout(
     RefPtr<Type>                structuredBufferType,
     RefPtr<Type>                elementType);
 
-
+int findGenericParam(List<RefPtr<GenericParamLayout>> & genericParameters, GlobalGenericParamDecl * decl);
 //
 
 }
diff --git a/tests/compute/global-type-param-in-entrypoint.slang b/tests/compute/global-type-param-in-entrypoint.slang
new file mode 100644
index 000000000..6a7720ad6
--- /dev/null
+++ b/tests/compute/global-type-param-in-entrypoint.slang
@@ -0,0 +1,95 @@
+//TEST(compute):COMPARE_RENDER_COMPUTE:-xslang -use-ir
+//TEST_INPUT: ubuffer(data=[0 0 0 0], stride=4):dxbinding(0),glbinding(0),out
+//TEST_INPUT: type VertImpl
+
+interface IVertInterpolant
+{
+	float4 getColor();
+}
+
+__generic_param TVertInterpolant : IVertInterpolant; 
+
+struct VertImpl : IVertInterpolant
+{
+	float3 color;
+	float4 getColor()
+	{
+		return float4(1.0);
+	}
+};
+
+RWStructuredBuffer<float> outputBuffer;
+
+cbuffer Uniforms
+{
+	float4x4 modelViewProjection;
+}
+
+struct AssembledVertex
+{
+	float3	position;
+	TVertInterpolant interpolants;
+    float2  uv;
+};
+
+struct CoarseVertex
+{
+	TVertInterpolant	interpolants;
+    float2  uv;
+};
+
+struct Fragment
+{
+	float4 color;
+};
+
+
+// Vertex  Shader
+
+struct VertexStageInput
+{
+	AssembledVertex assembledVertex	: A;
+};
+
+struct VertexStageOutput
+{
+	CoarseVertex	coarseVertex	: CoarseVertex;
+	float4			sv_position		: SV_Position;
+};
+
+VertexStageOutput vertexMain(VertexStageInput input)
+{
+	VertexStageOutput output;
+
+	float3 position = input.assembledVertex.position;
+	output.coarseVertex.interpolants = input.assembledVertex.interpolants;
+	output.sv_position = mul(modelViewProjection, float4(position, 1.0));
+    output.coarseVertex.uv = input.assembledVertex.uv;
+	return output;
+}
+
+// Fragment Shader
+
+struct FragmentStageInput
+{
+	CoarseVertex	coarseVertex	: CoarseVertex;
+};
+
+struct FragmentStageOutput
+{
+	Fragment fragment	: SV_Target;
+};
+
+FragmentStageOutput fragmentMain(FragmentStageInput input)
+{
+	FragmentStageOutput output;
+
+	float4 color = input.coarseVertex.interpolants.getColor();
+    float2 uv = input.coarseVertex.uv;
+	output.fragment.color = color;
+    outputBuffer[0] = color.x;
+    outputBuffer[1] = color.y;
+    outputBuffer[2] = color.z;
+    outputBuffer[3] = color.w;
+	return output;
+}
\ No newline at end of file
diff --git a/tests/compute/global-type-param-in-entrypoint.slang.expected.txt b/tests/compute/global-type-param-in-entrypoint.slang.expected.txt
new file mode 100644
index 000000000..e143b7f20
--- /dev/null
+++ b/tests/compute/global-type-param-in-entrypoint.slang.expected.txt
@@ -0,0 +1,4 @@
+3F800000
+3F800000
+3F800000
+3F800000
\ No newline at end of file
diff --git a/tools/render-test/render-d3d11.cpp b/tools/render-test/render-d3d11.cpp
index cdd6c778e..d0280a770 100644
--- a/tools/render-test/render-d3d11.cpp
+++ b/tools/render-test/render-d3d11.cpp
@@ -457,10 +457,7 @@ public:
 
     UInt RoundUpToAlignment(UInt size, UInt alignment)
     {
-        if (size % alignment)
-            return (size / alignment + 1) * alignment;
-        else
-            return Math::Max(size, alignment);
+        return ((size + alignment - 1) / alignment) * alignment;
     }
 
     virtual Buffer* createBuffer(BufferDesc const& desc) override
diff --git a/tools/render-test/slang-support.cpp b/tools/render-test/slang-support.cpp
index 746967cb7..e26fccc34 100644
--- a/tools/render-test/slang-support.cpp
+++ b/tools/render-test/slang-support.cpp
@@ -82,12 +82,12 @@ struct SlangShaderCompilerWrapper : public ShaderCompiler
 			spSetCompileFlags(slangRequest, SLANG_COMPILE_FLAG_NO_CHECKING);
 		}
 		ShaderProgram * result = nullptr;
+        Slang::List<const char*> rawTypeNames;
+        for (auto typeName : request.entryPointTypeArguments)
+            rawTypeNames.Add(typeName.Buffer());
 		if (request.computeShader.name)
 		{
-            Slang::List<const char*> rawTypeNames;
-            for (auto typeName : request.entryPointTypeArguments)
-                rawTypeNames.Add(typeName.Buffer());
-			int computeEntryPoint = spAddEntryPointEx(slangRequest, computeTranslationUnit, 
+		    int computeEntryPoint = spAddEntryPointEx(slangRequest, computeTranslationUnit, 
                 computeEntryPointName, 
                 spFindProfile(slangSession, request.computeShader.profile),
                 (int)rawTypeNames.Count(),
@@ -107,8 +107,8 @@ struct SlangShaderCompilerWrapper : public ShaderCompiler
 		}
 		else
 		{
-			int vertexEntryPoint = spAddEntryPoint(slangRequest, vertexTranslationUnit, vertexEntryPointName, spFindProfile(slangSession, request.vertexShader.profile));
-			int fragmentEntryPoint = spAddEntryPoint(slangRequest, fragmentTranslationUnit, fragmentEntryPointName, spFindProfile(slangSession, request.fragmentShader.profile));
+			int vertexEntryPoint = spAddEntryPointEx(slangRequest, vertexTranslationUnit, vertexEntryPointName, spFindProfile(slangSession, request.vertexShader.profile), rawTypeNames.Count(), rawTypeNames.Buffer());
+			int fragmentEntryPoint = spAddEntryPointEx(slangRequest, fragmentTranslationUnit, fragmentEntryPointName, spFindProfile(slangSession, request.fragmentShader.profile), rawTypeNames.Count(), rawTypeNames.Buffer());
 
 			int compileErr = spCompile(slangRequest);
 			if (auto diagnostics = spGetDiagnosticOutput(slangRequest))