--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/testsuite/g++.dg/opt/pr94441.C	Mon May 25 07:50:57 2020 +0900
@@ -0,0 +1,16 @@
+// PR debug/94441
+// { dg-do compile }
+// { dg-options "-O3 -fno-forward-propagate --param=max-cse-insns=0 -flive-range-shrinkage -std=c++17 -fcompare-debug" }
+
+template <class,class> struct Same;
+template <class T> struct Same<T,T> {};
+
+auto f()
+{
+  if constexpr (sizeof(int)==3)
+    return 42;
+  else
+    return 42L;
+}
+
+Same<decltype(f()), long> s;