1 files changed, 39 insertions, 0 deletions
diff --git a/tests/codegen/placement-new.rs b/tests/codegen/placement-new.rs
new file mode 100644
index 00000000000..0ec2b6a6f20
--- /dev/null
+++ b/tests/codegen/placement-new.rs
@@ -0,0 +1,39 @@
+//@ compile-flags: -O
+//@ compile-flags: -Zmerge-functions=disabled
+#![crate_type = "lib"]
+
+// Test to check that types with "complex" destructors, but trivial `Default` impls
+// are constructed directly into the allocation in `Box::default` and `Arc::default`.
+
+use std::rc::Rc;
+use std::sync::Arc;
+
+// CHECK-LABEL: @box_default_inplace
+#[no_mangle]
+pub fn box_default_inplace() -> Box<(String, String)> {
+    // CHECK-NOT: alloca
+    // CHECK: [[BOX:%.*]] = {{.*}}call {{.*}}__rust_alloc(
+    // CHECK-NOT: call void @llvm.memcpy
+    // CHECK: ret ptr [[BOX]]
+    Box::default()
+}
+
+// CHECK-LABEL: @rc_default_inplace
+#[no_mangle]
+pub fn rc_default_inplace() -> Rc<(String, String)> {
+    // CHECK-NOT: alloca
+    // CHECK: [[RC:%.*]] = {{.*}}call {{.*}}__rust_alloc(
+    // CHECK-NOT: call void @llvm.memcpy
+    // CHECK: ret ptr [[RC]]
+    Rc::default()
+}
+
+// CHECK-LABEL: @arc_default_inplace
+#[no_mangle]
+pub fn arc_default_inplace() -> Arc<(String, String)> {
+    // CHECK-NOT: alloca
+    // CHECK: [[ARC:%.*]] = {{.*}}call {{.*}}__rust_alloc(
+    // CHECK-NOT: call void @llvm.memcpy
+    // CHECK: ret ptr [[ARC]]
+    Arc::default()
+}