Added switch-case support; fixed non-diff parameter transposition (#2596)

2 files changed, 61 insertions, 0 deletions

diff --git a/tests/autodiff/reverse-switch-case.slang b/tests/autodiff/reverse-switch-case.slang
new file mode 100644
index 000000000..21a7565af
--- /dev/null
+++ b/tests/autodiff/reverse-switch-case.slang
@@ -0,0 +1,55 @@
+//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 float.Differential dfloat;
+
+[BackwardDifferentiable]
+float test_simple_switch(float y, int i)
+{
+    float o;
+    switch (i)
+    {
+        case 0:
+        case 1:
+            o = y * 2.0;
+            break;
+        
+        case 2:
+            o = y * 3.0;
+            break;
+        
+        default:
+            o = y;
+    }
+
+    return o;
+}
+
+[numthreads(1, 1, 1)]
+void computeMain(uint3 dispatchThreadID : SV_DispatchThreadID)
+{
+    {
+        dpfloat dpa = dpfloat(1.0, 0.0);
+
+        __bwd_diff(test_simple_switch)(dpa, 1, 1.0f);
+        outputBuffer[0] = dpa.d; // Expect: 2.0
+    }
+
+    {
+        dpfloat dpa = dpfloat(0.4, 0.0);
+        
+        __bwd_diff(test_simple_switch)(dpa, 2, 1.0f);
+        outputBuffer[1] = dpa.d; // Expect: 3.0
+    }
+
+    {
+        dpfloat dpa = dpfloat(1.0, 0.0);
+
+        __bwd_diff(test_simple_switch)(dpa, 3, 1.0f);
+        outputBuffer[2] = dpa.d; // Expect: 1.0
+    }
+}
diff --git a/tests/autodiff/reverse-switch-case.slang.expected.txt b/tests/autodiff/reverse-switch-case.slang.expected.txt
new file mode 100644
index 000000000..6e3b3dd12
--- /dev/null
+++ b/tests/autodiff/reverse-switch-case.slang.expected.txt
@@ -0,0 +1,6 @@
+type: float
+2.000000
+3.000000
+1.000000
+0.000000
+0.000000