Handle partial existential parameter type specialization. (#1568)

* Specialize exsitentials parameters in struct fields.

* Cleanup.

* Handle partial existential parameter type specialization.

Co-authored-by: Yong He <yhe@nvidia.com>

2 files changed, 9 insertions, 3 deletions

diff --git a/source/slang/slang-ir-insts.h b/source/slang/slang-ir-insts.h
index ef382373f..658e50f28 100644
--- a/source/slang/slang-ir-insts.h
+++ b/source/slang/slang-ir-insts.h
@@ -1807,7 +1807,7 @@ struct IRBuilder
     IRInOutType*  getInOutType(IRType* valueType);
     IRRefType*  getRefType(IRType* valueType);
     IRPtrTypeBase*  getPtrType(IROp op, IRType* valueType);
-    IRExistentialBoxType* getExistentialBoxType(IRType* concreteType, IRType* interfaceType);
+    IRType* getExistentialBoxType(IRType* concreteType, IRType* interfaceType);
 
     IRArrayTypeBase* getArrayTypeBase(
         IROp    op,
diff --git a/source/slang/slang-ir.cpp b/source/slang/slang-ir.cpp
index e9d90adfe..3820119d2 100644
--- a/source/slang/slang-ir.cpp
+++ b/source/slang/slang-ir.cpp
@@ -2336,10 +2336,14 @@ namespace Slang
             operands);
     }
 
-    IRExistentialBoxType* IRBuilder::getExistentialBoxType(IRType* concreteType, IRType* interfaceType)
+    IRType* IRBuilder::getExistentialBoxType(IRType* concreteType, IRType* interfaceType)
     {
+        // Don't wrap an existential box if concreteType is __Dynamic.
+        if (as<IRDynamicType>(concreteType))
+            return interfaceType;
+
         IRInst* operands[] = {concreteType, interfaceType};
-        return (IRExistentialBoxType*)getType(kIROp_ExistentialBoxType, 2, operands);
+        return getType(kIROp_ExistentialBoxType, 2, operands);
     }
 
     IRArrayTypeBase* IRBuilder::getArrayTypeBase(
@@ -2845,6 +2849,8 @@ namespace Slang
                 // We want to emit `makeExistential(load(value), witnessTable)`.
                 //
                 auto deref = emitLoad(value);
+                if (slotArgs[0]->op == kIROp_DynamicType)
+                    return deref;
                 return emitMakeExistential(type, deref, slotArgs[1]);
             }
         }