Allow mixing unspecialized and specialized existential parameters. (#1533)

* Allow mixing unspecialized and specialized existential parameters.

* Fixes.

2 files changed, 47 insertions, 0 deletions

diff --git a/tests/compute/dynamic-dispatch-12.slang b/tests/compute/dynamic-dispatch-12.slang
new file mode 100644
index 000000000..67598033d
--- /dev/null
+++ b/tests/compute/dynamic-dispatch-12.slang
@@ -0,0 +1,43 @@
+// Test using interface typed shader parameters with dynamic dispatch.
+
+//TEST(compute):COMPARE_COMPUTE:-cpu
+//DISABLE_TEST(compute):COMPARE_COMPUTE:-cuda -xslang -disable-specialization
+
+[anyValueSize(8)]
+interface IInterface
+{
+    int run(int input);
+}
+
+//TEST_INPUT:ubuffer(data=[0 0 0 0], stride=4):out,name=gOutputBuffer
+RWStructuredBuffer<int> gOutputBuffer;
+
+//TEST_INPUT:cbuffer(data=[rtti(MyImpl) witness(MyImpl, IInterface) 1 0], stride=4):name=gCb
+ConstantBuffer<IInterface> gCb;
+
+//TEST_INPUT:cbuffer(data=[rtti(MyImpl) witness(MyImpl, IInterface) 1 0], stride=4):name=gCb1
+ConstantBuffer<IInterface> gCb1;
+
+[numthreads(4, 1, 1)]
+void computeMain(uint3       dispatchThreadID : SV_DispatchThreadID)
+{
+    let tid = dispatchThreadID.x;
+
+    let inputVal : int = tid;
+    let outputVal = gCb.run(inputVal) + gCb1.run(inputVal);
+
+    gOutputBuffer[tid] = outputVal;
+}
+
+// Specialize gCb1, but not gCb2
+//TEST_INPUT: globalExistentialType MyImpl
+//TEST_INPUT: globalExistentialType __Dynamic
+// Type must be marked `public` to ensure it is visible in the generated DLL.
+public struct MyImpl : IInterface
+{
+    int val;
+    int run(int input)
+    {
+        return input + val;
+    }
+};
diff --git a/tests/compute/dynamic-dispatch-12.slang.expected.txt b/tests/compute/dynamic-dispatch-12.slang.expected.txt
new file mode 100644
index 000000000..628d2a8fd
--- /dev/null
+++ b/tests/compute/dynamic-dispatch-12.slang.expected.txt
@@ -0,0 +1,4 @@
+2
+4
+6
+8