cavis/libnd4j/include/ops/declarable/generic/shape/expand_dims.cpp

/*******************************************************************************
 * Copyright (c) 2015-2018 Skymind, Inc.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Apache License, Version 2.0 which is available at
 * https://www.apache.org/licenses/LICENSE-2.0.
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations
 * under the License.
 *
 * SPDX-License-Identifier: Apache-2.0
 ******************************************************************************/

//
// Created by raver119 on 02.11.2017.
//

#include <system/op_boilerplate.h>
#if NOT_EXCLUDED(OP_expand_dims)

#include <ops/declarable/CustomOperations.h>

namespace sd {
    namespace ops {
        CUSTOM_OP_IMPL(expand_dims, 1, 1, false, 0, -2) {
            auto input = INPUT_VARIABLE(0);
            auto output = OUTPUT_VARIABLE(0);

            if (input->isScalar()) {
                output->assign(input);
                return Status::OK();
            }

            Nd4jLong axis = block.numI() > 0 ? INT_ARG(0) : INPUT_VARIABLE(1)->e<int>(0);

            if (axis < 0)
                axis += input->rankOf() + 1;

            REQUIRE_TRUE(axis >= 0 && axis <= input->rankOf()+1, 0, "ExpandDims: axis should be in range of 0...%i in this case, but got %i instead", input->rankOf() + 1, axis);

            std::vector<Nd4jLong> shape(input->rankOf());

            for(int e = 0; e < input->rankOf(); e++)
                shape[input->sizeAt(e)];

            shape.insert(shape.begin() + axis, 1);

            if (input->ews() == 1 && output->ews() == 1 && input->ordering() == output->ordering()) {
                output->dataBuffer()->copyBufferFrom(*input->dataBuffer().get(), output->lengthOf() * DataTypeUtils::sizeOfElement(output->dataType()), 0, input->bufferOffset());
            } else {
                auto tmp = input->reshape(input->ordering(), shape);
                output->assign(tmp);
            }
            return Status::OK();
        }

        DECLARE_TYPES(expand_dims) {
            getOpDescriptor()
                    ->setAllowedInputTypes(sd::DataType::ANY)
                    ->setSameMode(true);
        }

        DECLARE_SHAPE_FN(expand_dims) {
            auto inShape = inputShape->at(0);

            // 0D scalar edge case
            if (shape::rank(inShape) == 0) {

                Nd4jLong x = 1;
                auto newShape = ConstantShapeHelper::getInstance()->createShapeInfo(ArrayOptions::dataType(inShape), 'c', 1, &x);
                return SHAPELIST(newShape);
            }

            // FIXME: temp workaround for TF
            if (shape::isScalar(inShape)) {                
                auto newShape = ConstantShapeHelper::getInstance()->createShapeInfo(ArrayOptions::dataType(inShape), 'c', 2, shape::shapeOf(inShape));
                return SHAPELIST(newShape);
            }

            auto x_rank = shape::rank(inShape);
            char order = shape::order(inShape);

            Nd4jLong axis = block.numI() > 0 ? INT_ARG(0) : INPUT_VARIABLE(1)->e<int>(0);

            if (axis < 0)
                axis += x_rank + 1;

            std::vector<Nd4jLong> shape;
            for(int e = 0; e < x_rank; e++)
                shape.emplace_back(shape::shapeOf(inShape)[e]);

            shape.insert(shape.begin() + axis, 1);

            auto newShape = ConstantShapeHelper::getInstance()->createShapeInfo(ArrayOptions::dataType(inShape), order, shape);
            return SHAPELIST(newShape);
        }
    }
}

#endif