Check subscript/property accessor for differentiability. (#5922)

1 files changed, 33 insertions, 0 deletions

diff --git a/tests/autodiff/subscript.slang b/tests/autodiff/subscript.slang
new file mode 100644
index 000000000..2b16597c0
--- /dev/null
+++ b/tests/autodiff/subscript.slang
@@ -0,0 +1,33 @@
+//TEST:COMPARE_COMPUTE(filecheck-buffer=CHK): -output-using-type
+
+interface ITest
+{
+    __subscript(int i) -> float
+    {
+        [BackwardDifferentiable] get;
+    }
+}
+struct Test : ITest
+{
+    __subscript(int i) -> float
+    {
+        [BackwardDifferentiable] get { return 5.0f * i; }
+    }
+}
+
+[Differentiable]
+float test(ITest arg)
+{
+    return arg[1];
+}
+
+//TEST_INPUT:set output = out ubuffer(data=[0 0 0 0], stride=4)
+RWStructuredBuffer<float> output;
+
+[numthreads(1,1,1)]
+void computeMain()
+{
+    Test t = {};
+    output[0] = test(t);
+    // CHK: 5.0
+}
\ No newline at end of file