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)

1 files changed, 22 insertions, 1 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);