1 | /* |
2 | * Licensed to the Apache Software Foundation (ASF) under one |
3 | * or more contributor license agreements. See the NOTICE file |
4 | * distributed with this work for additional information |
5 | * regarding copyright ownership. The ASF licenses this file |
6 | * to you under the Apache License, Version 2.0 (the |
7 | * "License"); you may not use this file except in compliance |
8 | * with the License. You may obtain a copy of the License at |
9 | * |
10 | * http://www.apache.org/licenses/LICENSE-2.0 |
11 | * |
12 | * Unless required by applicable law or agreed to in writing, |
13 | * software distributed under the License is distributed on an |
14 | * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
15 | * KIND, either express or implied. See the License for the |
16 | * specific language governing permissions and limitations |
17 | * under the License. |
18 | */ |
19 | |
20 | /*! |
21 | * \file ravel_unravel.h |
22 | * \brief Index ravel and unraval operations |
23 | */ |
24 | #ifndef TVM_TOPI_DETAIL_RAVEL_UNRAVEL_H_ |
25 | #define TVM_TOPI_DETAIL_RAVEL_UNRAVEL_H_ |
26 | |
27 | #include <tvm/te/operation.h> |
28 | |
29 | #include <vector> |
30 | |
31 | namespace tvm { |
32 | namespace topi { |
33 | namespace detail { |
34 | |
35 | using namespace tvm::te; |
36 | |
37 | /*! |
38 | * \brief Flatten the indices to 1D |
39 | * |
40 | * \param indices The input coordinates |
41 | * \param shape Shape of the tensor |
42 | * |
43 | * \return The index after flattening |
44 | */ |
45 | inline PrimExpr RavelIndex(Array<PrimExpr> indices, Array<PrimExpr> shape) { |
46 | ICHECK_EQ(indices.size(), shape.size()) << "indices and shape must have equal size" ; |
47 | if (indices.size() == 0U) { |
48 | return 0; |
49 | } |
50 | PrimExpr idx; |
51 | for (size_t i = 0; i < indices.size(); ++i) { |
52 | if (i == 0) { |
53 | idx = indices[i]; |
54 | } else { |
55 | idx = idx * shape[i] + indices[i]; |
56 | } |
57 | } |
58 | return idx; |
59 | } |
60 | |
61 | /*! |
62 | * \brief Convert flattened index to coordinate array |
63 | * |
64 | * \param idx The 1D index |
65 | * \param shape Shape of the tensor |
66 | * |
67 | * \return The coordinate corresponding to the 1D index |
68 | */ |
69 | inline Array<PrimExpr> UnravelIndex(PrimExpr idx, Array<PrimExpr> shape) { |
70 | std::vector<PrimExpr> indices; |
71 | |
72 | for (int i = static_cast<int>(shape.size()) - 1; i >= 0; --i) { |
73 | indices.push_back(indexmod(idx, shape[i])); |
74 | idx = indexdiv(idx, shape[i]); |
75 | } |
76 | std::reverse(indices.begin(), indices.end()); |
77 | return indices; |
78 | } |
79 | |
80 | } // namespace detail |
81 | } // namespace topi |
82 | } // namespace tvm |
83 | #endif // TVM_TOPI_DETAIL_RAVEL_UNRAVEL_H_ |
84 | |