cavis/libnd4j/include/ops/declarable/helpers/cuda/maximum.cu

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/*******************************************************************************
* 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
******************************************************************************/
//
// @author sgazeos@gmail.com
//
#include <op_boilerplate.h>
#include <NDArray.h>
#include <helpers/ShapeUtils.h>
namespace nd4j {
namespace ops {
namespace helpers {
template <typename T>
void maximumBPFunctor_(NDArray* x, NDArray* y, NDArray* epsNext, NDArray* gradX, NDArray* gradY) {
auto lambdaX = LAMBDA_TTT(_e, _x, _y) {
return _x >= _y ? _e : (T) 0.;
};
auto lambdaY = LAMBDA_TTT(_e, _x, _y) {
return _x <= _y ? _e : (T) 0.;
};
if (x->isSameShape(y)) {
// PWT case case
// X gradient
epsNext->applyTriplewiseLambda(*x, *y, lambdaX, *gradX);
// Y gradient
epsNext->applyTriplewiseLambda(*x, *y, lambdaY, *gradY);
} else if (y->isScalar()) {
T s = y->e<T>(0);
auto lambdaS = LAMBDA_TT(_e, _x, s) {
return _x >= s ? _e : (T) 0.;
};
// scalar case
auto tmp = epsNext->reduceNumber(reduce::Sum);
if (x <= y)
gradY->assign(tmp);
else
gradY->assign(0.0f);
epsNext->applyPairwiseLambda(*x, lambdaS, *gradX);
} else {
// broadcast case
// in this case we want to boost our X and Y shapes to the size of FF pass output (or epsNext, which has the same shape)
auto preX = x->dup();
auto preY = y->dup();
auto targetShape = epsNext->getShapeAsVector();
preX.tileToShape(targetShape, preX);
preY.tileToShape(targetShape, preY);
epsNext->applyTriplewiseLambda(preX, preY, lambdaX, preX);
epsNext->applyTriplewiseLambda(preX, preY, lambdaY, preY);
auto axisX = ShapeUtils::evalBroadcastBackwardAxis(x->shapeInfo(), epsNext->shapeInfo());
auto axisY = ShapeUtils::evalBroadcastBackwardAxis(y->shapeInfo(), epsNext->shapeInfo());
if (axisX.size() > 0) {
auto sum = preX.reduceAlongDimension(reduce::Sum, axisX);
gradX->assign(sum);
} else
gradX->assign(preX);
if (axisY.size() > 0) {
auto sum = preY.reduceAlongDimension(reduce::Sum, axisY);
gradY->assign(sum);
} else
gradY->assign(preY);
}
}
void maximumBPFunctor(nd4j::LaunchContext * context, NDArray* x, NDArray* y, NDArray* epsNext, NDArray* gradX, NDArray* gradY) {
NDArray::prepareSpecialUse({gradX, gradY}, {x, y, epsNext});
BUILD_SINGLE_SELECTOR(x->dataType(), maximumBPFunctor_, (x, y, epsNext, gradX, gradY), NUMERIC_TYPES);
NDArray::registerSpecialUse({gradX, gradY}, {x, y, epsNext});
}
}
}
}