Move /src/test to /tests

1 files changed, 24 insertions, 0 deletions

diff --git a/tests/codegen/mem-replace-direct-memcpy.rs b/tests/codegen/mem-replace-direct-memcpy.rs
new file mode 100644
index 00000000000..e8bbf0e1bbd
--- /dev/null
+++ b/tests/codegen/mem-replace-direct-memcpy.rs
@@ -0,0 +1,24 @@
+// This test ensures that `mem::replace::<T>` only ever calls `@llvm.memcpy`
+// with `size_of::<T>()` as the size, and never goes through any wrapper that
+// may e.g. multiply `size_of::<T>()` with a variable "count" (which is only
+// known to be `1` after inlining).
+
+// compile-flags: -C no-prepopulate-passes -Zinline-mir=no
+// ignore-debug: the debug assertions get in the way
+
+#![crate_type = "lib"]
+
+pub fn replace_byte(dst: &mut u8, src: u8) -> u8 {
+    std::mem::replace(dst, src)
+}
+
+// NOTE(eddyb) the `CHECK-NOT`s ensure that the only calls of `@llvm.memcpy` in
+// the entire output, are the two direct calls we want, from `ptr::replace`.
+
+// CHECK-NOT: call void @llvm.memcpy
+// CHECK: ; core::mem::replace
+// CHECK-NOT: call void @llvm.memcpy
+// CHECK: call void @llvm.memcpy.{{.+}}({{i8\*|ptr}} align 1 %{{.*}}, {{i8\*|ptr}} align 1 %{{.*}}, i{{.*}} 1, i1 false)
+// CHECK-NOT: call void @llvm.memcpy
+// CHECK: call void @llvm.memcpy.{{.+}}({{i8\*|ptr}} align 1 %{{.*}}, {{i8\*|ptr}} align 1 %{{.*}}, i{{.*}} 1, i1 false)
+// CHECK-NOT: call void @llvm.memcpy