Fix issues around dynamic generic function and autodiff. (#2528)

* Fix issues around dynamic generic function and autodiff.

* Fix return type issue.

* Fix type unification for generic `inout` parameter.

* Fix.

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

1 files changed, 49 insertions, 0 deletions

diff --git a/tests/autodiff/dynamic-dispatch-generic-2.slang b/tests/autodiff/dynamic-dispatch-generic-2.slang
new file mode 100644
index 000000000..bbf7c7da1
--- /dev/null
+++ b/tests/autodiff/dynamic-dispatch-generic-2.slang
@@ -0,0 +1,49 @@
+// Test calling differentiable function through dynamic dispatch.
+
+//TEST(compute):COMPARE_COMPUTE_EX:-slang -compute -shaderobj -output-using-type
+//TEST(compute, vulkan):COMPARE_COMPUTE_EX:-vk -compute -shaderobj -output-using-type
+
+//TEST_INPUT:ubuffer(data=[0 0 0 0 0], stride=4):out,name=outputBuffer
+RWStructuredBuffer<float> outputBuffer;
+
+[anyValueSize(16)]
+interface IInterface
+{
+    [ForwardDifferentiable]
+    float calc(float x);
+}
+
+struct A : IInterface
+{
+    float z;
+    [ForwardDifferentiable]
+    float calc(float x) { return x * x * x; }
+};
+
+struct B : IInterface
+{
+    float z;
+
+    [ForwardDifferentiable]
+    float calc(float x) { return x * x + z; }
+};
+
+[ForwardDifferentiable]
+float sqr<T:IInterface>(T obj, float x)
+{
+    return obj.calc(x);
+}
+
+//TEST_INPUT: type_conformance A:IInterface = 0
+//TEST_INPUT: type_conformance B:IInterface = 1
+
+
+[numthreads(1, 1, 1)]
+void computeMain(uint3 dispatchThreadID : SV_DispatchThreadID)
+{
+    var obj = createDynamicObject<IInterface>(dispatchThreadID.x, 0); // A
+    outputBuffer[0] = __fwd_diff(sqr)(obj, DifferentialPair<float>(2.0, 1.0)).d; // A.calc, expect 12
+
+    obj = createDynamicObject<IInterface>(dispatchThreadID.x + 1, 0); // B
+    outputBuffer[1] = __fwd_diff(sqr)(obj, DifferentialPair<float>(1.5, 1.0)).d; // B.calc, expect 3
+}