1 files changed, 57 insertions, 0 deletions
diff --git a/tests/bugs/gh-5781.slang b/tests/bugs/gh-5781.slang
new file mode 100644
index 000000000..33456f500
--- /dev/null
+++ b/tests/bugs/gh-5781.slang
@@ -0,0 +1,57 @@
+//TEST:SIMPLE(filecheck=CHECK): -target spirv
+// CHECK: OpEntryPoint
+
+module test;
+
+public enum class MaterialID : uint { invalid = 0xffffffff };
+
+public struct Material : IDifferentiable
+{
+    float x;
+}
+
+public struct Hit
+{
+    MaterialID material;
+}
+
+public struct Scene
+{
+    StructuredBuffer<Material> materials;
+    RWStructuredBuffer<Material> grads;
+
+    [Differentiable]
+    Material load(MaterialID id) { return materials[uint(id)]; }
+
+    void accumulate(MaterialID id, Material d) { grads[uint(id)].x += d.x; }
+
+    [Differentiable, BackwardDerivative(_get_material_bwd)]
+    public Material get_material(MaterialID id) { return load(id); }
+
+    public void _get_material_bwd(MaterialID id, Material d) { accumulate(id, d); }
+
+    [Differentiable]
+    public Material get_material(Hit hit) { return get_material(hit.material); }
+}
+
+[Differentiable]
+float trace(const Scene scene, Hit hit)
+{
+    Material m = scene.get_material(hit);
+    return m.x;
+}
+
+
+[shader("compute")]
+void main(
+    uniform Scene scene,
+    uniform StructuredBuffer<uint> input,
+    uniform RWStructuredBuffer<float> output,
+    uniform RWStructuredBuffer<float> grads
+)
+{
+    Hit hit;
+    hit.material = MaterialID(input[0]);
+    output[0] = trace(scene, hit);
+    bwd_diff(trace)(scene, hit, grads[0]);
+}
+\ No newline at end of file