Extend `no_diff` to support subscript operations on resources and array variables… (#2981)

* Extend `no_diff` to support subscript operations on resources and array variables

* Update autodiff.slang.expected

1 files changed, 23 insertions, 0 deletions

diff --git a/tests/autodiff/no-diff-array-access.slang b/tests/autodiff/no-diff-array-access.slang
new file mode 100644
index 000000000..df8c8faa0
--- /dev/null
+++ b/tests/autodiff/no-diff-array-access.slang
@@ -0,0 +1,23 @@
+//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;
+
+typedef DifferentialPair<float> dpfloat;
+typedef DifferentialPair<float3> dpfloat3;
+
+[ForwardDifferentiable]
+float f(float x, float[3] y)
+{
+    return x * no_diff(outputBuffer[4]) + y[2] * x * no_diff(y[1]);
+}
+
+
+[numthreads(1, 1, 1)]
+void computeMain(uint3 dispatchThreadID : SV_DispatchThreadID)
+{
+    var dpx = fwd_diff(f)(DifferentialPair<float>(1.0f, 1.0f), DifferentialPair<float[3]>( { 1.0f, 2.0f, 3.0f }, { 1.0f, 2.0f, 3.0f }));
+    outputBuffer[0] = dpx.p; // Expect: 6.0
+    outputBuffer[1] = dpx.d; // Expect: 12.0
+}