}
(_, "init") => {
let tp_ty = *substs.types.get(FnSpace, 0);
- let lltp_ty = type_of::arg_type_of(ccx, tp_ty);
- if return_type_is_void(ccx, tp_ty) {
- C_nil(ccx)
- } else {
- C_null(lltp_ty)
+ if !return_type_is_void(ccx, tp_ty) {
+ // Just zero out the stack slot. (See comment on base::memzero for explaination)
+ zero_mem(bcx, llresult, tp_ty);
}
+ C_nil(ccx)
}
// Effectively no-ops
(_, "uninit") | (_, "forget") => {
--- /dev/null
+// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// Makes sure that zero-initializing large types is reasonably fast,
+// Doing it incorrectly causes massive slowdown in LLVM during
+// optimisation.
+
+#![feature(intrinsics)]
+
+extern "rust-intrinsic" {
+ pub fn init<T>() -> T;
+}
+
+const SIZE: usize = 1024 * 1024;
+
+fn main() {
+ let _memory: [u8; SIZE] = unsafe { init() };
+}