1 | /* Copyright 2019 Google LLC. All Rights Reserved. |
2 | |
3 | Licensed under the Apache License, Version 2.0 (the "License"); |
4 | you may not use this file except in compliance with the License. |
5 | You may obtain a copy of the License at |
6 | |
7 | http://www.apache.org/licenses/LICENSE-2.0 |
8 | |
9 | Unless required by applicable law or agreed to in writing, software |
10 | distributed under the License is distributed on an "AS IS" BASIS, |
11 | WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
12 | See the License for the specific language governing permissions and |
13 | limitations under the License. |
14 | ==============================================================================*/ |
15 | |
16 | #ifndef RUY_RUY_SIDE_PAIR_H_ |
17 | #define RUY_RUY_SIDE_PAIR_H_ |
18 | |
19 | #include "ruy/check_macros.h" |
20 | |
21 | namespace ruy { |
22 | |
23 | // Enumeration of the sides, i.e. the operands 'slots', in a matrix |
24 | // multiplication. The numerical values of these enumeration constants matter |
25 | // because these will be used as indices into the array underlying a SidePair. |
26 | enum class Side { |
27 | // Left-hand side |
28 | kLhs = 0, |
29 | // Right-hand side |
30 | kRhs = 1 |
31 | }; |
32 | |
33 | inline Side OtherSide(Side side) { |
34 | return side == Side::kLhs ? Side::kRhs : Side::kLhs; |
35 | } |
36 | |
37 | // SidePair is a pair container where the two elements are indexed by a Side |
38 | // enum. |
39 | template <typename T> |
40 | class SidePair final { |
41 | public: |
42 | SidePair() {} |
43 | SidePair(const T& a, const T& b) : elem_{a, b} {} |
44 | const T& operator[](Side side) const { |
45 | const int index = static_cast<int>(side); |
46 | // Technically this check is vacuous, since other values would be |
47 | // out-of-range for enum Side. |
48 | RUY_DCHECK(index == 0 || index == 1); |
49 | return elem_[index]; |
50 | } |
51 | |
52 | T& operator[](Side side) { |
53 | const int index = static_cast<int>(side); |
54 | // Technically this check is vacuous, since other values would be |
55 | // out-of-range for enum Side. |
56 | RUY_DCHECK(index == 0 || index == 1); |
57 | return elem_[index]; |
58 | } |
59 | |
60 | private: |
61 | static_assert(static_cast<int>(Side::kLhs) == 0, "" ); |
62 | static_assert(static_cast<int>(Side::kRhs) == 1, "" ); |
63 | T elem_[2]; |
64 | }; |
65 | |
66 | } // namespace ruy |
67 | |
68 | #endif // RUY_RUY_SIDE_PAIR_H_ |
69 | |