Specialize witness table lookups. (#1596)

* Specialize witness table lookups.

* Remove generated files from vcxproj

* Fix call to generic interface methods.

2 files changed, 79 insertions, 0 deletions

diff --git a/tests/compute/dynamic-dispatch-14.slang b/tests/compute/dynamic-dispatch-14.slang
new file mode 100644
index 000000000..5d84a3ee6
--- /dev/null
+++ b/tests/compute/dynamic-dispatch-14.slang
@@ -0,0 +1,75 @@
+// Test using interface typed shader parameters with associated types.
+
+//TEST(compute):COMPARE_COMPUTE:-cpu
+//TEST(compute):COMPARE_COMPUTE:-cuda
+
+[anyValueSize(8)]
+interface IAssoc
+{
+    int eval();
+}
+
+[anyValueSize(8)]
+interface IInterface
+{
+    associatedtype TAssoc : IAssoc;
+    TAssoc run(int input);
+}
+
+//TEST_INPUT:ubuffer(data=[0 0 0 0], stride=4):out,name=gOutputBuffer
+RWStructuredBuffer<int> gOutputBuffer;
+
+//TEST_INPUT:ubuffer(data=[rtti(MyImpl) witness(MyImpl, IInterface) 1 0], stride=4):name=gCb
+StructuredBuffer<IInterface> gCb;
+
+//TEST_INPUT:ubuffer(data=[rtti(MyImpl) witness(MyImpl, IInterface) 1 0], stride=4):name=gCb1
+StructuredBuffer<IInterface> gCb1;
+
+[numthreads(4, 1, 1)]
+void computeMain(uint3       dispatchThreadID : SV_DispatchThreadID)
+{
+    let tid = dispatchThreadID.x;
+
+    let inputVal : int = tid;
+    IInterface v0 = gCb.Load(0);
+    IInterface v1 = gCb1[0];
+    let outputVal = v0.run(inputVal).eval() + v1.run(inputVal).eval();
+
+    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;
+    public struct TAssoc : IAssoc
+    {
+        int val;
+        int eval() { return val; }
+    }
+    TAssoc run(int input)
+    {
+        TAssoc rs;
+        rs.val = input + val;
+        return rs;
+    }
+};
+
+public struct MyImpl2 : IInterface
+{
+    int val;
+    public struct TAssoc : IAssoc
+    {
+        int val;
+        int eval() { return val; }
+    }
+    TAssoc run(int input)
+    {
+        TAssoc rs;
+        rs.val = input - val;
+        return rs;
+    }
+};
\ No newline at end of file
diff --git a/tests/compute/dynamic-dispatch-14.slang.expected.txt b/tests/compute/dynamic-dispatch-14.slang.expected.txt
new file mode 100644
index 000000000..628d2a8fd
--- /dev/null
+++ b/tests/compute/dynamic-dispatch-14.slang.expected.txt
@@ -0,0 +1,4 @@
+2
+4
+6
+8