xref: /freebsd/contrib/llvm-project/compiler-rt/lib/orc/stl_extras.h (revision e63d20b70ee1dbee9b075f29de6f30cdcfe1abe1)
1 //===-------- stl_extras.h - Useful STL related functions-------*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file is a part of the ORC runtime support library.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #ifndef ORC_RT_STL_EXTRAS_H
14 #define ORC_RT_STL_EXTRAS_H
15 
16 #include <cstdint>
17 #include <utility>
18 #include <tuple>
19 
20 namespace __orc_rt {
21 
22 /// Substitute for std::identity.
23 /// Switch to std::identity once we can use c++20.
24 template <class Ty> struct identity {
25   using is_transparent = void;
26   using argument_type = Ty;
27 
28   Ty &operator()(Ty &self) const { return self; }
29   const Ty &operator()(const Ty &self) const { return self; }
30 };
31 
32 /// Substitute for std::bit_ceil.
33 constexpr uint64_t bit_ceil(uint64_t Val) noexcept {
34   Val |= (Val >> 1);
35   Val |= (Val >> 2);
36   Val |= (Val >> 4);
37   Val |= (Val >> 8);
38   Val |= (Val >> 16);
39   Val |= (Val >> 32);
40   return Val + 1;
41 }
42 
43 } // namespace __orc_rt
44 
45 #endif // ORC_RT_STL_EXTRAS
46