Various AD Fixes (#3263)

* Various fixes

* Remove unused parameter

* Update slang-ir-loop-unroll.cpp

---------

Co-authored-by: Yong He <yonghe@outlook.com>

2 files changed, 40 insertions, 0 deletions

diff --git a/tests/autodiff/generic-differential-synthesis.slang b/tests/autodiff/generic-differential-synthesis.slang
new file mode 100644
index 000000000..8c858b9b3
--- /dev/null
+++ b/tests/autodiff/generic-differential-synthesis.slang
@@ -0,0 +1,35 @@
+//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], stride=4):out,name=outputBuffer
+RWStructuredBuffer<float> outputBuffer;
+
+__generic<let C : int>
+struct Foo : IDifferentiable
+{
+    float x[C];
+};
+
+[Differentiable]
+Foo<3> getFoo(float x)
+{
+    return { { x, x, x } };
+}
+
+[Differentiable]
+float foobar(float x)
+{
+    int i = 3 * int(floor(x));
+    Foo<3> foo = getFoo(x);
+    return foo.x[i] * foo.x[i];
+}
+
+[numthreads(1, 1, 1)]
+void computeMain(uint3 dispatchThreadID: SV_DispatchThreadID)
+{
+    {
+        float a = 0.5;
+        var d = fwd_diff(foobar)(diffPair(a, 1.0)).d;
+        outputBuffer[0] = d;
+    }
+}
diff --git a/tests/autodiff/generic-differential-synthesis.slang.expected.txt b/tests/autodiff/generic-differential-synthesis.slang.expected.txt
new file mode 100644
index 000000000..97de29f1f
--- /dev/null
+++ b/tests/autodiff/generic-differential-synthesis.slang.expected.txt
@@ -0,0 +1,5 @@
+type: float
+1.000000
+0.000000
+0.000000
+0.000000