Fix def-use issue from multi-level break elimination (#6134)

1 files changed, 60 insertions, 0 deletions

diff --git a/tests/autodiff/loop-mutating-array.slang b/tests/autodiff/loop-mutating-array.slang
new file mode 100644
index 000000000..0eada5153
--- /dev/null
+++ b/tests/autodiff/loop-mutating-array.slang
@@ -0,0 +1,60 @@
+//TEST(compute, vulkan):COMPARE_COMPUTE_EX(filecheck-buffer=CHECK):-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;
+
+
+struct SpatialVertex : IDifferentiable
+{
+    float x;
+};
+
+struct MaterialVertex
+{
+    float x;
+};
+
+//TEST_INPUT:ubuffer(data=[2.0 2.0 2.0 2.0 2.0], stride=4):name=pathVertices
+RWStructuredBuffer<MaterialVertex> pathVertices;
+
+[Differentiable]
+SpatialVertex transform(float p, MaterialVertex m)
+{
+    return { p * m.x };
+}
+
+[Differentiable]
+float test_simple_loop(float y)
+{
+    SpatialVertex vShade[2];
+    int pathLength = 1;
+
+    [ForceUnroll]
+    for (int i = 0; i < 2; i++)
+    {
+        if (!(pathVertices[i].x > 1.4))
+        {
+            pathLength = i;
+            break;
+        }
+
+        vShade[i] = transform(y, pathVertices[i]);
+    }
+
+    return vShade[0].x + vShade[1].x;
+}
+
+[numthreads(1, 1, 1)]
+void computeMain(uint3 dispatchThreadID : SV_DispatchThreadID)
+{
+    {
+        dpfloat dpy = dpfloat(1.0, 1.0);
+
+        var dpresult = fwd_diff(test_simple_loop)(dpy);
+        outputBuffer[0] = pathVertices[0].x; // CHECK: 2.0
+        outputBuffer[1] = dpresult.d; // CHECK: 4.0
+    }
+}