From 1a0bbb53c116e6e5f89ed577803341e6aa1bce82 Mon Sep 17 00:00:00 2001
From: ArielG-NV <159081215+ArielG-NV@users.noreply.github.com>
Date: Fri, 12 Jul 2024 11:46:38 -0400
Subject: [PATCH] use `nullptr' for IRStructKey with
 `IRDerivativeMemberDecoration` (#4623)

---
 source/slang/slang-emit.cpp                   |  1 +
 .../struct-autodiff-default-init.slang        | 25 +++++++++++++++++++
 2 files changed, 26 insertions(+)
 create mode 100644 tests/compute/struct-autodiff-default-init.slang

diff --git a/source/slang/slang-emit.cpp b/source/slang/slang-emit.cpp
index 243dd65e84..d3f6ebd8d1 100644
--- a/source/slang/slang-emit.cpp
+++ b/source/slang/slang-emit.cpp
@@ -292,6 +292,7 @@ void calcRequiredLoweringPassSet(RequiredLoweringPassSet& result, CodeGenContext
     case kIROp_BackwardDifferentiate:
     case kIROp_ForwardDifferentiate:
     case kIROp_MakeDifferentialPairUserCode:
+    case kIROp_DerivativeMemberDecoration:
         result.autodiff = true;
         break;
     case kIROp_VerticesType:
diff --git a/tests/compute/struct-autodiff-default-init.slang b/tests/compute/struct-autodiff-default-init.slang
new file mode 100644
index 0000000000..3d65481255
--- /dev/null
+++ b/tests/compute/struct-autodiff-default-init.slang
@@ -0,0 +1,25 @@
+// struct-default-init.slang
+//TEST:SIMPLE(filecheck=HLSL): -target hlsl -entry computeMain -stage compute
+//TEST:SIMPLE(filecheck=GLSL): -target glsl -entry computeMain -stage compute
+//TEST:SIMPLE(filecheck=METAL): -target metal -entry computeMain -stage compute
+//TEST:SIMPLE(filecheck=CPP): -target cpp -entry computeMain -stage compute
+//TEST:SIMPLE(filecheck=SPIRV): -target spirv -entry computeMain -stage compute
+
+// HLSL: computeMain
+// GLSL: main
+// METAL: computeMain
+// CPP: computeMain
+// SPIRV: OpEntryPoint
+
+struct PowActivationEx : IDifferentiable
+{
+	float power;
+}
+RWStructuredBuffer<float> return_value;
+
+[numthreads(256, 1, 1)]
+void computeMain()
+{
+    PowActivationEx args;
+	return_value[0] = args.power;
+}
\ No newline at end of file