--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/testsuite/g++.dg/ipa/pr93223.C	Thu Feb 13 11:34:05 2020 +0900
@@ -0,0 +1,62 @@
+/* { dg-do compile } */
+/* { dg-options "-O3 -std=gnu++14" } */
+
+template <typename Function>
+bool run(const int item_count,
+         Function && process_range,
+         const int max_parallelism,
+         int* progress = nullptr)
+{
+    if (max_parallelism <= 1)
+    {
+        if (progress == nullptr)
+        {
+            return process_range(0);
+        }
+        else
+        {
+            auto result = true;
+            for (int i = 0; i != item_count && result; ++i)
+            {
+                (*progress)++;
+                result = process_range(i);
+            }
+            return result;
+        }
+    }
+
+    if (max_parallelism > 10)
+    {
+        if (progress == nullptr)
+        {
+            return process_range(0);
+        }
+        else
+        {
+            auto result = true;
+            for (int i = 0; i != item_count && result; ++i)
+            {
+                (*progress)++;
+                result = process_range(i);
+            }
+            return result;
+        }
+    }
+    return false;
+}
+
+namespace
+{
+__attribute__((optimize(0))) bool worker_fun(const int)
+{
+    return true;
+}
+}
+
+void demo(int n)
+{
+    for (int i = 0; i < n; ++i)
+    {
+        run(n, &worker_fun, n);
+    }
+}