source: mainline/uspace/lib/cpp/include/internal/builtins.hpp@ a629655

lfn serial ticket/834-toolchain-update topic/msim-upgrade topic/simplify-dev-export
Last change on this file since a629655 was a629655, checked in by Dzejrou <dzejrou@…>, 7 years ago

cpp: added a constexpr pow builtin wrapper

  • Property mode set to 100644
File size: 2.9 KB
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1/*
2 * Copyright (c) 2018 Jaroslav Jindrak
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *
9 * - Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * - Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * - The name of the author may not be used to endorse or promote products
15 * derived from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29#ifndef LIBCPP_INTERNAL_BUILTINS
30#define LIBCPP_INTERNAL_BUILTINS
31
32/**
33 * Note: While the primary target of libcpp is the
34 * g++ compiler, using builtin functions that would
35 * unnecessarily limit the library to any specific
36 * compiler is discouraged and as such all the used
37 * builtins should be available atleast in g++ and
38 * clang++.
39 * GCC: https://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html
40 * LLVM: https://github.com/llvm-mirror/clang/blob/master/include/clang/Basic/Builtins.def
41 * (If anyone has a better link for LLVM, feel free to update it.)
42 */
43
44#include <cstdlib>
45
46namespace std::aux
47{
48 template<class T>
49 constexpr double log2(T val)
50 {
51 return __builtin_log2(static_cast<double>(val));
52 }
53
54 template<class T>
55 constexpr double pow2(T exp)
56 {
57 return __builtin_pow(2.0, static_cast<double>(exp));
58 }
59
60 template<class T>
61 constexpr size_t pow2u(T exp)
62 {
63 return static_cast<size_t>(pow2(exp));
64 }
65
66 template<class T, class U>
67 constexpr T pow(T base, U exp)
68 {
69 return static_cast<T>(
70 __builtin_pow(static_cast<double>(base), static_cast<double>(exp))
71 );
72 }
73
74 template<class T>
75 constexpr size_t ceil(T val)
76 {
77 return static_cast<size_t>(__builtin_ceil(static_cast<double>(val)));
78 }
79
80 template<class T>
81 constexpr size_t floor(T val)
82 {
83 return static_cast<size_t>(__builtin_floor(static_cast<double>(val)));
84 }
85}
86
87#endif
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