/Users/deen/code/yugabyte-db/src/yb/util/bit-util.h
Line | Count | Source |
1 | | // Licensed to the Apache Software Foundation (ASF) under one |
2 | | // or more contributor license agreements. See the NOTICE file |
3 | | // distributed with this work for additional information |
4 | | // regarding copyright ownership. The ASF licenses this file |
5 | | // to you under the Apache License, Version 2.0 (the |
6 | | // "License"); you may not use this file except in compliance |
7 | | // with the License. You may obtain a copy of the License at |
8 | | // |
9 | | // http://www.apache.org/licenses/LICENSE-2.0 |
10 | | // |
11 | | // Unless required by applicable law or agreed to in writing, |
12 | | // software distributed under the License is distributed on an |
13 | | // "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
14 | | // KIND, either express or implied. See the License for the |
15 | | // specific language governing permissions and limitations |
16 | | // under the License. |
17 | | // |
18 | | // The following only applies to changes made to this file as part of YugaByte development. |
19 | | // |
20 | | // Portions Copyright (c) YugaByte, Inc. |
21 | | // |
22 | | // Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except |
23 | | // in compliance with the License. You may obtain a copy of the License at |
24 | | // |
25 | | // http://www.apache.org/licenses/LICENSE-2.0 |
26 | | // |
27 | | // Unless required by applicable law or agreed to in writing, software distributed under the License |
28 | | // is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express |
29 | | // or implied. See the License for the specific language governing permissions and limitations |
30 | | // under the License. |
31 | | // |
32 | | // Licensed under the Apache License, Version 2.0 (the "License"); |
33 | | // you may not use this file except in compliance with the License. |
34 | | // You may obtain a copy of the License at |
35 | | // |
36 | | // http://www.apache.org/licenses/LICENSE-2.0 |
37 | | // |
38 | | // Unless required by applicable law or agreed to in writing, software |
39 | | // distributed under the License is distributed on an "AS IS" BASIS, |
40 | | // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
41 | | // See the License for the specific language governing permissions and |
42 | | // limitations under the License. |
43 | | |
44 | | |
45 | | #ifndef YB_UTIL_BIT_UTIL_H |
46 | | #define YB_UTIL_BIT_UTIL_H |
47 | | |
48 | | #include <stdint.h> |
49 | | #include "yb/gutil/port.h" |
50 | | |
51 | | namespace yb { |
52 | | |
53 | | // Utility class to do standard bit tricks |
54 | | // TODO: is this in boost or something else like that? |
55 | | class BitUtil { |
56 | | public: |
57 | | // Returns the 'num_bits' least-significant bits of 'v'. |
58 | 9 | static inline uint64_t TrailingBits(uint64_t v, size_t num_bits) { |
59 | 9 | if (PREDICT_FALSE(num_bits == 0)) return 0; |
60 | 7 | if (PREDICT_FALSE(num_bits >= 64)) return v; |
61 | 3 | auto n = 64 - num_bits; |
62 | 3 | return (v << n) >> n; |
63 | 3 | } |
64 | | }; |
65 | | |
66 | | } // namespace yb |
67 | | |
68 | | #endif // YB_UTIL_BIT_UTIL_H |