1/*
2 * Copyright (C) 2018 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17// Contains the implementation of the operations.
18
19#define LOG_TAG "Operations"
20
21#include "Operations.h"
22#include "CpuOperationUtils.h"
23
24#include "tensorflow/contrib/lite/kernels/internal/reference/reference_ops.h"
25
26namespace android {
27namespace nn {
28
29bool stridedSliceGeneric(const uint8_t* inputData, const Shape& inputShape,
30                         const int32_t* beginData, const int32_t* endData,
31                         const int32_t* stridesData,
32                         int32_t beginMask, int32_t endMask, int32_t shrinkAxisMask,
33                         uint8_t* outputData, const Shape& outputShape) {
34    // This Op only supports 1-4D cases and since we use the reference 4D
35    // implementation, the 1-3D tensors are mapped to 4D.
36    const int kMaxDim = 4;
37
38    std::vector<int> starts;
39    std::vector<int> stops;
40    std::vector<int> strides;
41
42    int32_t numInputDims = static_cast<int32_t>(getNumberOfDimensions(inputShape));
43    for (int32_t idx = numInputDims - 1; idx >= 0; --idx) {
44      int32_t dim = static_cast<int32_t>(getSizeOfDimension(inputShape, idx));
45      int32_t stride = stridesData[idx];
46      // stride value has to be non-zero
47      NN_OPS_CHECK(stride != 0);
48      bool positiveStride = stride > 0;
49
50      int32_t begin = beginMask & (1 << idx)
51              ? positiveStride ? 0 : dim - 1
52              : ClampedIndex(beginData[idx], dim, positiveStride);
53      int32_t end = endMask & (1 << idx)
54              ? positiveStride ? dim : -1
55              : ClampedIndex(endData[idx], dim, positiveStride);
56
57      starts.emplace_back(begin);
58      stops.emplace_back(end);
59      strides.emplace_back(stride);
60    }
61
62    for (int i = numInputDims; i < kMaxDim; i++) {
63      starts.emplace_back(0);
64      stops.emplace_back(1);
65      strides.emplace_back(1);
66    }
67
68    beginMask = ReverseMaskBits(beginMask, numInputDims);
69    endMask = ReverseMaskBits(endMask, numInputDims);
70    shrinkAxisMask = ReverseMaskBits(shrinkAxisMask, numInputDims);
71
72    if (inputShape.type == OperandType::TENSOR_FLOAT32) {
73        tflite::reference_ops::StridedSlice(
74                reinterpret_cast<const float*>(inputData),
75                convertShapeToDims(inputShape),
76                beginMask, endMask, shrinkAxisMask,
77                starts, stops, strides,
78                reinterpret_cast<float*>(outputData),
79                convertShapeToDims(outputShape));
80    } else if (inputShape.type == OperandType::TENSOR_QUANT8_ASYMM) {
81        tflite::reference_ops::StridedSlice(
82                reinterpret_cast<const uint8_t*>(inputData),
83                convertShapeToDims(inputShape),
84                beginMask, endMask, shrinkAxisMask,
85                starts, stops, strides,
86                reinterpret_cast<uint8_t*>(outputData),
87                convertShapeToDims(outputShape));
88    } else {
89        LOG(ERROR) << "Unsupported data type";
90        return false;
91    }
92
93    return true;
94}
95
96} // namespace nn
97} // namespace android
98