From 9da1d3e2a6c89f1b2acf0db410f9368aa56a35aa Mon Sep 17 00:00:00 2001
From: "William S. Moses" <gh@wsmoses.com>
Date: Tue, 22 Oct 2024 17:12:03 -0400
Subject: [PATCH] Don't store undef value sret

---
 enzyme/Enzyme/CApi.cpp | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/enzyme/Enzyme/CApi.cpp b/enzyme/Enzyme/CApi.cpp
index 4e583273698..14215fb6dd2 100644
--- a/enzyme/Enzyme/CApi.cpp
+++ b/enzyme/Enzyme/CApi.cpp
@@ -1966,6 +1966,12 @@ void EnzymeFixupJuliaCallingConvention(LLVMValueRef F_C) {
             outinds.push_back(ConstantInt::get(B.getInt32Ty(), v));
           }
 
+          if (isa<UndefValue>(in) || isa<PoisonValue>(in))
+            return;
+
+          if (isa<UndefValue>(out) || isa<PoisonValue>(out))
+            return;
+
           if (outinds.size() > 1)
             out = B.CreateInBoundsGEP(sretTy, out, outinds);
           if (ininds.size() > 1)