Switched to a much simpler method to transpose control flow, nested control flow works now (#2595)

2 files changed, 88 insertions, 0 deletions

diff --git a/tests/autodiff/reverse-nested-control-flow.slang b/tests/autodiff/reverse-nested-control-flow.slang
new file mode 100644
index 000000000..f6020d539
--- /dev/null
+++ b/tests/autodiff/reverse-nested-control-flow.slang
@@ -0,0 +1,82 @@
+//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_if_only(float y)
+{
+    float o = y + 1.0f;
+    if (y > 0.5)
+    {
+        o = y * 2.0f;
+    }
+
+    return o;
+}
+
+[BackwardDifferentiable]
+float test_nested_ifelse(float y)
+{
+    float o = 0.f;
+    if (y > 0.5)
+    {
+        o = y * 2.0f;
+    }
+    else
+    {
+        if (y > 0.25)
+        {
+            o = y * 3.0f + 2.0f;
+        }
+        else
+        {
+            o = y * 4.0f;
+        }
+    }
+
+    return o;
+}
+
+[numthreads(1, 1, 1)]
+void computeMain(uint3 dispatchThreadID : SV_DispatchThreadID)
+{
+    {
+        dpfloat dpa = dpfloat(1.0, 0.0);
+
+        __bwd_diff(test_nested_ifelse)(dpa, 1.0f);
+        outputBuffer[0] = dpa.d; // Expect: 2.0
+    }
+
+    {
+        dpfloat dpa = dpfloat(0.4, 0.0);
+        
+        __bwd_diff(test_nested_ifelse)(dpa, 1.0f);
+        outputBuffer[1] = dpa.d; // Expect: 3.0
+    }
+
+    {
+        dpfloat dpa = dpfloat(0.2, 0.0);
+        
+        __bwd_diff(test_nested_ifelse)(dpa, 1.0f);
+        outputBuffer[2] = dpa.d; // Expect: 4.0
+    }
+
+    {
+        dpfloat dpa = dpfloat(1.0, 0.0);
+
+        __bwd_diff(test_if_only)(dpa, 1.0f);
+        outputBuffer[3] = dpa.d; // Expect: 2.0
+    }
+
+    {
+        dpfloat dpa = dpfloat(0.4, 0.0);
+        
+        __bwd_diff(test_if_only)(dpa, 1.0f);
+        outputBuffer[4] = dpa.d; // Expect: 1.0
+    }
+}
diff --git a/tests/autodiff/reverse-nested-control-flow.slang.expected.txt b/tests/autodiff/reverse-nested-control-flow.slang.expected.txt
new file mode 100644
index 000000000..d12f4774e
--- /dev/null
+++ b/tests/autodiff/reverse-nested-control-flow.slang.expected.txt
@@ -0,0 +1,6 @@
+type: float
+2.000000
+3.000000
+4.000000
+2.000000
+1.000000