1 files changed, 37 insertions, 0 deletions
diff --git a/gcc/testsuite/g++.dg/init/new17.C b/gcc/testsuite/g++.dg/init/new17.C
new file mode 100644
index 000000000..42b9f077a
--- /dev/null
+++ b/gcc/testsuite/g++.dg/init/new17.C
@@ -0,0 +1,37 @@
+// { dg-do compile }
+// { dg-options "-O2 -fstrict-aliasing -fdump-tree-optimized" }
+
+// Test that placement new does not introduce an unnecessary memory
+// barrier.
+// See PR 29286.
+
+typedef __SIZE_TYPE__ size_t;
+
+inline void* operator new(size_t, void* __p) throw() { return __p; }
+
+template <class T, int D>
+class Vector
+{
+public:
+   Vector()
+   {
+     for (int i = 0; i < D; ++i)
+        new (&x_m[i]) T();
+   }
+   T& operator[](int i) { return x_m[i]; }
+
+private:
+   T x_m[D];
+};
+
+void foo(Vector<float, 3> *m)
+{
+  Vector<float, 3> v;
+  v[0] = 1.0;
+  v[1] = 2.0;
+  v[3] = 3.0;
+  *m = v;
+}
+
+// { dg-final { scan-tree-dump-times "= 0\.0" 1 "optimized" } }
+// { dg-final { cleanup-tree-dump "optimized" } }