deeplearning4j--deeplearning4j/libnd4j/include/ops/declarable/generic/helpers/BroadcastHelper.h

/* ******************************************************************************
 *
 *
 * 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.
 *
 *  See the NOTICE file distributed with this work for additional
 *  information regarding copyright ownership.
 * 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
 ******************************************************************************/

//
//  @author raver119@gmail.com
//

#ifndef LIBND4J_BROADCAST_HELPER_H
#define LIBND4J_BROADCAST_HELPER_H

#include <array/NDArray.h>
#include <array/NDArrayFactory.h>
#include <helpers/ShapeUtils.h>
#include <ops/BroadcastBoolOpsTuple.h>
#include <ops/BroadcastOpsTuple.h>

namespace sd {
namespace ops {
class BroadcastHelper {
 public:
  static SD_INLINE NDArray* broadcastApply(BroadcastOpsTuple op, NDArray* x, NDArray* y, NDArray* z,
                                           ExtraArguments* extraArgs = nullptr) {
    if (x->isEmpty() || y->isEmpty()) {
      return z;
    }

    if (x->lengthOf() > 1 && y->lengthOf() > 1 && x->isSameShape(y)) {
      x->applyPairwiseTransform(op.p, y, z, extraArgs);
    } else if (x->lengthOf() > 1 && y->lengthOf() <= 1) {
      x->applyScalarArr(op.s, y, z);
    } else if (x->lengthOf() <= 1 && y->lengthOf() > 1) {
      NDArray &xRef = *x;
      NDArray &yRef = *y;
      if (z->isSameShape(y)) {
        if (op.s == scalar::Add || op.s == scalar::Multiply) {
          y->applyScalarArr(op.s, x, z);
        } else if (op.s == scalar::SquaredSubtract) {
          y->applyScalarArr(scalar::SquaredReverseSubtract, x, z);
        } else if (op.s == scalar::Subtract) {
          y->applyScalarArr(scalar::ReverseSubtract, x, z);
        } else if (op.s == scalar::Divide) {
          y->applyScalarArr(scalar::ReverseDivide, x, z);
        } else if (op.s == scalar::Pow) {
          y->applyScalarArr(scalar::ReversePow, x, z);
        } else if (op.s == scalar::ReverseSubtract) {
          y->applyScalarArr(scalar::Subtract, x, z);
        } else if (op.s == scalar::ReverseDivide) {
          y->applyScalarArr(scalar::Divide, x, z);
        } else if (op.s == scalar::MaxPairwise || op.s == scalar::MinPairwise || op.s == scalar::AMaxPairwise ||
                   op.s == scalar::AMinPairwise) {
          y->applyScalarArr(op.s, x, z);
        } else if (op.s == scalar::CopyPws) {
          z->assign(&yRef);
        } else {
          z->assign(&xRef);
          z->applyPairwiseTransform(op.p, y, extraArgs);
        }
        return z;
      } else {
        auto v = y->getShapeAsVector();
        auto tZ = NDArrayFactory::valueOf(v, y, y->ordering());
        tZ->applyPairwiseTransform(op.p, y, extraArgs);
        return tZ;
      }
    } else if (x->lengthOf() <= 1 && y->lengthOf() <= 1) {
      x->applyScalarArr(op.s, y, z);
    } else if (ShapeUtils::areShapesBroadcastable(*x, *y)) {
      x->applyTrueBroadcast(op, y, z, true, extraArgs);
      return z;
    } else {
      auto sx = ShapeUtils::shapeAsString(x);
      auto sy = ShapeUtils::shapeAsString(y);
      sd_printf("Broadcast: shapes should be equal, or broadcastable. But got %s vs %s instead\n", sx.c_str(),
                sy.c_str());
      return nullptr;
    }

    return z;
  }

  static SD_INLINE NDArray* broadcastApply(BroadcastBoolOpsTuple op, NDArray* x, NDArray* y, NDArray* z,
                                           ExtraArguments* extraArgs = nullptr) {
    if (x->isEmpty() || y->isEmpty()) {
      if (!z->isEmpty()) {
        std::string errorMessage;
        errorMessage += "BroadcastHelper::broadcastApply: when some of input arrays (or both) is empty, output array must be empty as well !";
        errorMessage += "X is empty: ";
        errorMessage += std::to_string(x->isEmpty());
        errorMessage += "Y is empty: ";
        errorMessage += std::to_string(y->isEmpty());
        THROW_EXCEPTION(
            errorMessage.c_str());
      }
      return z;
    }

    if (!x->isScalar() && !y->isScalar() && x->isSameShape(y)) {
      x->applyPairwiseTransform(op.p, y, z);
    } else if (ShapeUtils::areShapesBroadcastable(*x, *y)) {
      x->applyTrueBroadcast(op, y, z, true, extraArgs);
      return z;
    } else if (!x->isScalar() && y->isScalar()) {
      x->applyScalarArr(op.s, y, z);
    } else if (x->isScalar() && !y->isScalar()) {
      if (z->isSameShape(y)) {
        x->applyPairwiseTransform(op.p, y, z, extraArgs);
        return z;
      } else {
        auto v = y->getShapeAsVector();
        auto tZ = NDArrayFactory::valueOf(v, y, y->ordering());
        return tZ;
      }
    } else if (x->isScalar() && y->isScalar()) {  // x->isScalar() && y->isScalar()
      x->applyScalarArr(op.s, y, z);
    } else if (ShapeUtils::areShapesBroadcastable(*x, *y)) {
      x->applyTrueBroadcast(op, y, z, true, extraArgs);
      return z;
    } else {
      auto sx = ShapeUtils::shapeAsString(x);
      auto sy = ShapeUtils::shapeAsString(y);
      return nullptr;
    }

    return z;
  }
};
}  // namespace ops
}  // namespace sd

#endif