Allow unspecialized existential shader parameters (dynamic dispatch). (#1529)

* Allow unspecialized existential shader parameters (dynamic dispatch).

* Fixes.

* Fixes

* disable cuda test

1 files changed, 16 insertions, 0 deletions

diff --git a/source/slang/slang-type-layout.cpp b/source/slang/slang-type-layout.cpp
index 9b00fc88c..dbdfaf79c 100644
--- a/source/slang/slang-type-layout.cpp
+++ b/source/slang/slang-type-layout.cpp
@@ -3613,6 +3613,22 @@ static TypeLayoutResult _createTypeLayout(
             typeLayout->type = type;
             typeLayout->rules = rules;
 
+            if (isCPUTarget(context.targetReq) || isCUDATarget(context.targetReq))
+            {
+                LayoutSize fixedSize = 16;
+                if (auto anyValueAttr =
+                        interfaceDeclRef.getDecl()->findModifier<AnyValueSizeAttribute>())
+                {
+                    fixedSize += anyValueAttr->size;
+                }
+                else
+                {
+                    // The interface type does not have an `[anyValueSize]` attribute,
+                    // assume a default of 8 bytes.
+                    fixedSize += 8;
+                }
+                typeLayout->addResourceUsage(LayoutResourceKind::Uniform, fixedSize);
+            }
             typeLayout->addResourceUsage(LayoutResourceKind::ExistentialTypeParam, 1);
             typeLayout->addResourceUsage(LayoutResourceKind::ExistentialObjectParam, 1);