diff --git a/src/test/codegen/nrvo.rs b/src/test/codegen/nrvo.rs new file mode 100644 index 0000000000000..fddb0d1fb3c8c --- /dev/null +++ b/src/test/codegen/nrvo.rs @@ -0,0 +1,17 @@ +// compile-flags: -O + +#![crate_type = "lib"] + +// Ensure that we do not call `memcpy` for the following function. +// `memset` and `init` should be called directly on the return pointer. +#[no_mangle] +pub fn nrvo(init: fn(&mut [u8; 4096])) -> [u8; 4096] { + // CHECK-LABEL: nrvo + // CHECK: @llvm.memset + // CHECK-NOT: @llvm.memcpy + // CHECK: ret + // CHECK-EMPTY + let mut buf = [0; 4096]; + init(&mut buf); + buf +}