Auto synthesis of Differential type (#2466)

2 files changed, 64 insertions, 0 deletions

diff --git a/tests/autodiff/auto-differential-type.slang b/tests/autodiff/auto-differential-type.slang
new file mode 100644
index 000000000..f15fb6417
--- /dev/null
+++ b/tests/autodiff/auto-differential-type.slang
@@ -0,0 +1,58 @@
+// Tests automatic synthesis of Differential type requirement.
+
+//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;
+
+struct A : IDifferentiable
+{
+    float x;
+    float y;
+
+    [__unsafeForceInlineEarly]
+    static Differential zero()
+    {
+        Differential b = {0.0, 0.0};
+        return b;
+    }
+
+    [__unsafeForceInlineEarly]
+    static Differential dadd(Differential a, Differential b)
+    {
+        Differential o = {a.x + b.x, 0.0};
+        return o;
+    }
+
+    [__unsafeForceInlineEarly]
+    static Differential dmul(This a, Differential b)
+    {
+        Differential o = {a.x * b.x, 0.0};
+        return o;
+    }
+};
+
+typedef __DifferentialPair<A> dpA;
+
+__differentiate_jvp A f(A a)
+{
+    A aout;
+    aout.y = 2 * a.x;
+    aout.x = 5 * a.x;
+
+    return aout;
+}
+
+[numthreads(1, 1, 1)]
+void computeMain(uint3 dispatchThreadID : SV_DispatchThreadID)
+{
+    {
+        A a = {1.0, 2.0};
+        A.Differential b = {0.2};
+
+        dpA dpa = dpA(a, b);
+
+        outputBuffer[0] = __jvp(f)(dpa).d().x;                    // Expect: 1
+    }
+}
diff --git a/tests/autodiff/auto-differential-type.slang.expected.txt b/tests/autodiff/auto-differential-type.slang.expected.txt
new file mode 100644
index 000000000..ca54c9afe
--- /dev/null
+++ b/tests/autodiff/auto-differential-type.slang.expected.txt
@@ -0,0 +1,6 @@
+type: float
+1.000000
+0.000000
+0.000000
+0.000000
+0.000000