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2026-07-13 12:47:05 +08:00

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/* ******************************************************************************
*
*
* 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 Yurii Shyrma (iuriish@yahoo.com), created on 25.11.2017.
//
#include <system/op_boilerplate.h>
#if NOT_EXCLUDED(OP_softmax_cross_entropy_loss)
#include <ops/declarable/CustomOperations.h>
namespace sd {
namespace ops {
//////////////////////////////////////////////////////////////////////////
CUSTOM_OP_IMPL(softmax_cross_entropy_loss, 3, 1, false, 1, 1) {
auto logits = INPUT_VARIABLE(0);
auto weights = INPUT_VARIABLE(1);
auto labels = INPUT_VARIABLE(2);
auto output = OUTPUT_VARIABLE(0);
int reductionMode =
INT_ARG(0); // 0 - "none"; 1 - "weighted_sum"; 2 - "weighted_mean"; 3 - "weighted_sum_by_nonzero_weights"
double labelsSmoothing = T_ARG(0);
// input validation
REQUIRE_TRUE(labels->isSameShape(logits), 0,
"SOFTMAX_CROSS_ENTROPY_LOSS OP: labels and logits arrays must have the same shapes, but got %s and %s "
"correspondingly !",
ShapeUtils::shapeAsString(labels).c_str(), ShapeUtils::shapeAsString(logits).c_str());
// only 4 possible reduction modes exist
REQUIRE_TRUE(reductionMode == 0 || reductionMode == 1 || reductionMode == 2 || reductionMode == 3, 0,
"SOFTMAX_CROSS_ENTROPY_LOSS OP: reduction mode value is not acceptable, possible values are 0, 1, 2, 3, "
"but got %i instead!",
reductionMode);
// smoothing is possible for rank of logits/labels > 1
REQUIRE_TRUE(labels->rankOf() > 1 || (labels->rankOf() == 1 && labelsSmoothing == 0.), 0,
"SOFTMAX_CROSS_ENTROPY_LOSS OP: smoothing is not possible when rank of labels/ logits = 1 !");
if (!output->isScalar()) {
// weights array can be single scalar or has the same shape as output, and must be broadcastable to output shape
REQUIRE_TRUE(weights->isScalar() || weights->rankOf() == output->rankOf(), 0,
"SOFTMAX_CROSS_ENTROPY_LOSS OP: weights array should be scalar or have the same rank as output array, "
"but got %i and %i correspondingly!",
weights->rankOf(), output->rankOf());
// check whether broadcast operation is possible for weights array
REQUIRE_TRUE(weights->isScalar() || ShapeUtils::areShapesBroadcastable(*weights, *output), 0,
"SOFTMAX_CROSS_ENTROPY_LOSS OP: shapes of weights and output arrays should be broadcastable, but got "
"weights = %s and output = %s instead!",
ShapeUtils::shapeAsString(weights).c_str(), ShapeUtils::shapeAsString(labels).c_str());
}
// If label_smoothing is nonzero, smooth the labels towards 1/num_classes: new_onehot_labels = onehot_labels * (1 -
// label_smoothing) + label_smoothing / num_classes num_classes = labels->sizeAt(1)
NDArray* cLabels = labels->cast(weights->dataType()); // cast() already returns NDArray*
NDArray* newLabels = cLabels;
if (labelsSmoothing != 0.) {
newLabels = new NDArray(cLabels);
NDArray* term1 = (1.f - labelsSmoothing) * (*cLabels);
NDArray* term2 = (*term1) + (labelsSmoothing / cLabels->sizeAt(1));
delete term1;
newLabels->assign(term2);
delete term2;
}
// main formula: result = - sum_i(lables_i * log(softmax_i)) - sum over last dimension
// softmax_i = exp(logits_i) / sum_j(exp(logits_j))
// so result = sum_i( lables_i * (log(sum_j(exp(logits_j))) - logits_i) )
// for numerical stability we use shifted logits (one can approve this using simple math):
// softmax_i = exp(logits_i - maxLogit) / sum_j(exp(logits_j - maxLogit))
// maxLogit is max among logits_i
std::vector<LongType> dimensions = {-1};
NDArray* maxLogits = logits->reduceAlongDimension(reduce::Max, &dimensions, true);
NDArray* shiftedLogits_ptr = (*logits) - (*maxLogits);
delete maxLogits;
NDArray shiftedLogits = *shiftedLogits_ptr;
delete shiftedLogits_ptr;
NDArray* expShifted = shiftedLogits.transform(transform::Exp);
NDArray* sumExp = expShifted->reduceAlongDimension(reduce::Sum, &dimensions, true);
delete expShifted;
NDArray* logSumExp_ptr = sumExp->transform(transform::Log);
delete sumExp;
NDArray logSumExp = *logSumExp_ptr;
delete logSumExp_ptr;
// E = (newLabels * (logSumExp - shiftedLogits)).reduceAlongDimension(Sum)
NDArray* diff = logSumExp - shiftedLogits;
NDArray* product = (*newLabels) * (*diff);
delete diff;
NDArray* E_ptr = product->reduceAlongDimension(reduce::Sum, &dimensions);
delete product;
NDArray E = *E_ptr;
delete E_ptr;
// perform weights broadcasting/tile to E if it is necessary
auto weightsBroad = weights;
if (!weights->isScalar() && !weights->isSameShape(&E)) {
std::vector<LongType> weightsShape = {weights->lengthOf()};
if (E.rankOf() == 1 && weights->isVector() && weights->rankOf() > 1)
weightsBroad = weights->reshape(weights->ordering(), weightsShape);
else
weightsBroad = new NDArray(weights->tileToShape(E.shapeInfo()));
}
// multiply E on weights
E *= *weightsBroad;
switch (reductionMode) {
case 0: // 0 - "none", un-reduced weighted losses with the same shape as labels.
output->assign(&E);
break;
case 1: { // 1 - "weighted_sum", output is scalar and equal to sum of all elements of E array
E.reduceNumber(reduce::Sum, output);
break;
}
case 2: { // 2 - "weighted_mean", output is scalar and equal to sum of all elements of E array divided by sum of
// all elements of weightsBroad array
double sum;
if (weights->isScalar())
sum = weights->e<double>(0) * E.lengthOf();
else {
NDArray* sumPtr = weightsBroad->reduceNumber(reduce::Sum);
sum = sumPtr->e<double>(0);
delete sumPtr;
}
if (sum == 0.)
*output = 0.;
else {
NDArray* eSum = E.reduceNumber(reduce::Sum);
NDArray* result = (*eSum) / sum;
delete eSum;
output->assign(result);
delete result;
}
break;
}
case 3: { // 3 - "weighted_sum_by_nonzero_weights", output is scalar and equal to scalar sum of all elements of E
// array divided by number of non-zero weights
LongType numOfNonZeroWeights = 0;
if (weights->isScalar()) {
if (weights->e<double>(0) != 0.) numOfNonZeroWeights = E.lengthOf();
} else {
NDArray* countNonZero = weightsBroad->reduceNumber(reduce::CountNonZero);
numOfNonZeroWeights = countNonZero->e<LongType>(0);
delete countNonZero;
}
if (numOfNonZeroWeights == 0)
*output = 0.;
else {
NDArray* eSum = E.reduceNumber(reduce::Sum);
NDArray* result = (*eSum) / double(numOfNonZeroWeights);
delete eSum;
output->assign(result);
delete result;
}
break;
}
}
if (weightsBroad != weights) delete weightsBroad;
if (newLabels != cLabels) delete newLabels;
delete cLabels;
return Status::OK;
}
//////////////////////////////////////////////////////////////////////////
DECLARE_TYPES(softmax_cross_entropy_loss) {
getOpDescriptor()
->setAllowedInputTypes(0, {ALL_FLOATS})
->setAllowedInputTypes(1, {ALL_FLOATS})
->setAllowedInputTypes(2, {ALL_FLOATS, ALL_INTS})
->setAllowedOutputTypes({ALL_FLOATS});
}
//////////////////////////////////////////////////////////////////////////
DECLARE_SHAPE_FN(softmax_cross_entropy_loss) {
auto logitsShapeInfo = inputShape->at(0);
auto weightsShapeInfo = inputShape->at(1);
auto labelsShapeInfo = inputShape->at(2);
// labels and logits must have the same shapes
REQUIRE_TRUE(shape::shapeEquals(logitsShapeInfo, labelsShapeInfo), 0,
"SOFTMAX_CROSS_ENTROPY_LOSS OP: labels and logits arrays must have the same shapes, but got %s and %s "
"correspondingly!",
ShapeUtils::shapeAsString(labelsShapeInfo).c_str(), ShapeUtils::shapeAsString(logitsShapeInfo).c_str());
DataType outType = DataTypeUtils::pickFloatingType(ArrayOptions::dataType(logitsShapeInfo));
LongType* outShapeInfo = nullptr;
if (INT_ARG(0) != 0) // in this case output is scalar
outShapeInfo = ConstantShapeHelper::getInstance().scalarShapeInfo(outType);
else { // in this case output has the shape as labels and logits minus last dimension
std::vector<LongType> dimensions = {-1};
outShapeInfo = ShapeUtils::evalReduceShapeInfo(shape::order(logitsShapeInfo), &dimensions, logitsShapeInfo, false,
true, block.getWorkspace());
// weights array can be single scalar or has the same rank as output, and must be broadcastable to output
REQUIRE_TRUE(shape::isScalar(weightsShapeInfo) || shape::rank(weightsShapeInfo) == shape::rank(outShapeInfo), 0,
"SOFTMAX_CROSS_ENTROPY_LOSS OP: weights array should be scalar or have the same rank as output array, "
"but got %i and %i correspondingly!",
shape::rank(weightsShapeInfo), shape::rank(outShapeInfo));
// check whether broadcast operation is possible for weights array
REQUIRE_TRUE(
shape::isScalar(weightsShapeInfo) || ShapeUtils::areShapesBroadcastable(weightsShapeInfo, outShapeInfo), 0,
"SOFTMAX_CROSS_ENTROPY_LOSS OP: shapes of weights and output arrays should be broadcastable, but got weights = "
"%s and output = %s instead!",
ShapeUtils::shapeAsString(weightsShapeInfo).c_str(), ShapeUtils::shapeAsString(outShapeInfo).c_str());
}
return SHAPELIST(outShapeInfo);
}
//////////////////////////////////////////////////////////////////////////
CUSTOM_OP_IMPL(softmax_cross_entropy_loss_grad, 3, 3, false, 1, 1) {
auto logits = INPUT_VARIABLE(0);
auto weights = INPUT_VARIABLE(1);
auto labels = INPUT_VARIABLE(2);
auto dLdp = OUTPUT_VARIABLE(0); // dL/dlogits
auto dLdw = OUTPUT_VARIABLE(1); // dL/dweights
auto dLdl = OUTPUT_VARIABLE(2); // dL/dlabels
auto labelsSmoothing = T_ARG(0);
int reductionMode =
INT_ARG(0); // 0 - "none"; 1 - "weighted_sum"; 2 - "weighted_mean"; 3 - "weighted_sum_by_nonzero_weights"
// take into account Alex's proposition to treat "none" the same as "weighted_sum" mode when calculating gradients
if (reductionMode == 0) reductionMode = 1;
std::vector<LongType> *dimensions = new std::vector<LongType>({-1});
// input validation
REQUIRE_TRUE(labels->isSameShape(logits), 0,
"SOFTMAX_CROSS_ENTROPY_LOSS_GRAD OP: labels and logits arrays must have the same shapes, but got %s and "
"%s correspondingly !",
ShapeUtils::shapeAsString(labels).c_str(), ShapeUtils::shapeAsString(logits).c_str());
// only 4 possible reduction modes exist
REQUIRE_TRUE(reductionMode == 0 || reductionMode == 1 || reductionMode == 2 || reductionMode == 3, 0,
"SOFTMAX_CROSS_ENTROPY_LOSS_GRAD OP: reduction mode value is not acceptable, possible values are 0, 1, "
"2, 3, but got %i instead!",
reductionMode);
auto lossShapeInfo = ShapeUtils::evalReduceShapeInfo(logits->ordering(), dimensions, logits->shapeInfo(), false,
false, block.getWorkspace());
// weights array can be single scalar or has the same shape as loss, and must be broadcastable to loss shape
REQUIRE_TRUE(weights->isScalar() || weights->rankOf() == shape::rank(lossShapeInfo), 0,
"SOFTMAX_CROSS_ENTROPY_LOSS_GRAD OP: weights array should be scalar or have the same rank as loss "
"array, but got %i and %i correspondingly!",
weights->rankOf(), shape::rank(lossShapeInfo));
// check whether broadcast operation is possible for weights array
REQUIRE_TRUE(weights->isScalar() || ShapeUtils::areShapesBroadcastable(weights->shapeInfo(), lossShapeInfo), 0,
"SOFTMAX_CROSS_ENTROPY_LOSS_GRAD OP: shapes of weights and loss arrays should be broadcastable, but got "
"weights = %s and loss = %s instead!",
ShapeUtils::shapeAsString(weights).c_str(), ShapeUtils::shapeAsString(lossShapeInfo).c_str());
// smoothing is possible for rank of logits/labels > 1
REQUIRE_TRUE(labels->rankOf() > 1 || (labels->rankOf() == 1 && labelsSmoothing == 0.), 0,
"SOFTMAX_CROSS_ENTROPY_LOSS_GRAD OP: smoothing is not possible when rank of labels/ logits = 1 !");
// If label_smoothing is nonzero, smooth the labels towards 1/num_classes: new_onehot_labels = onehot_labels * (1 -
// label_smoothing) + label_smoothing / num_classes num_classes = labels->sizeAt(1)
NDArray* cLabels = labels->cast(weights->dataType()); // cast() already returns NDArray*
NDArray* newLabels = cLabels;
if (labelsSmoothing != 0.) {
newLabels = new NDArray(labels->shapeInfo(), dLdl->dataType(), false, block.launchContext());
NDArray* term1 = (1.f - labelsSmoothing) * (*cLabels);
NDArray* term2 = (*term1) + (labelsSmoothing / cLabels->sizeAt(1));
delete term1;
newLabels->assign(term2);
delete term2;
}
// Compute softmax
NDArray* maxLogits = logits->reduceAlongDimension(reduce::Max, dimensions, true);
NDArray* shiftedLogits_ptr = (*logits) - (*maxLogits);
delete maxLogits;
NDArray* expShifted = shiftedLogits_ptr->transform(transform::Exp);
delete shiftedLogits_ptr;
NDArray* sumExp = expShifted->reduceAlongDimension(reduce::Sum, dimensions, true);
NDArray* softmax_ptr = (*expShifted) / (*sumExp);
delete expShifted;
delete sumExp;
NDArray softmax = *softmax_ptr;
delete softmax_ptr;
// dEdp = softmax * sum_i(lables_i) - labels
NDArray* labelSum = newLabels->reduceAlongDimension(reduce::Sum, dimensions, true);
NDArray* softmaxTimesLabelSum = softmax * (*labelSum);
delete labelSum;
NDArray* dLdpTemp_ptr = (*softmaxTimesLabelSum) - (*newLabels);
delete softmaxTimesLabelSum;
dLdp->assign(dLdpTemp_ptr);
delete dLdpTemp_ptr;
// dEdl = -log(softmax)
NDArray* logSoftmax = softmax.transform(transform::Log);
NDArray negLogSoftmax = -(*logSoftmax); // unary negation returns value
delete logSoftmax;
NDArray* dLdlTemp_ptr = negLogSoftmax * (1.f - labelsSmoothing);
dLdl->assign(dLdlTemp_ptr);
delete dLdlTemp_ptr;
// Compute E for gradient calculations
NDArray* maxLogits2 = logits->reduceAlongDimension(reduce::Max, dimensions, true);
NDArray* shiftedLogits2_ptr = (*logits) - (*maxLogits2);
delete maxLogits2;
NDArray shiftedLogits = *shiftedLogits2_ptr;
delete shiftedLogits2_ptr;
NDArray* expShifted2 = shiftedLogits.transform(transform::Exp);
NDArray* sumExp2 = expShifted2->reduceAlongDimension(reduce::Sum, dimensions, true);
delete expShifted2;
NDArray* logSumExp_ptr = sumExp2->transform(transform::Log);
delete sumExp2;
NDArray logSumExp = *logSumExp_ptr;
delete logSumExp_ptr;
NDArray* diff = logSumExp - shiftedLogits;
NDArray* product = (*newLabels) * (*diff);
delete diff;
NDArray* E_ptr = product->reduceAlongDimension(reduce::Sum, dimensions);
delete product;
NDArray E = *E_ptr;
delete E_ptr;
// perform weights broadcasting/tile to E if it is necessary
auto weightsBroad = weights;
if (!weights->isScalar() && !weights->isSameShape(&E))
weightsBroad = new NDArray(weights->tileToShape(E.shapeInfo()));
auto excludeDims = ShapeUtils::evalDimsToExclude(dLdp->rankOf(), dimensions->size(), dimensions->data());
switch (reductionMode) {
case 1: { // 1 - "none" and "weighted_sum", output is scalar and equal to sum of all elements of E array
if (weights->isScalar() || weights->lengthOf() == 1) {
NDArray* eSum = E.reduceNumber(reduce::Sum);
dLdw->assign(eSum);
delete eSum;
*dLdp *= *weights;
*dLdl *= *weights;
} else {
dLdp->applyBroadcast(broadcast::Multiply, excludeDims, weightsBroad, dLdp);
dLdl->applyBroadcast(broadcast::Multiply, excludeDims, weightsBroad, dLdl);
if (weights != weightsBroad) {
std::vector<LongType> axesToReduceAlong =
ShapeUtils::evalBroadcastBackwardAxis(weights->shapeInfo(), weightsBroad->shapeInfo());
E.reduceAlongDimension(reduce::Sum, dLdw, &axesToReduceAlong, true);
} else
dLdw->assign(&E);
}
break;
}
case 2: { // 2 - "weighted_mean", output is scalar and equal to sum of all elements of E array divided by sum of
// all elements of weightsBroad array
NDArray* sum_ptr = nullptr;
if (weights->isScalar())
sum_ptr = (*weights) * E.lengthOf();
else
sum_ptr = weightsBroad->reduceNumber(reduce::Sum);
NDArray sum = *sum_ptr;
delete sum_ptr;
if (sum.e<double>(0) == 0.) {
*dLdp = 0.;
*dLdl = 0.;
*dLdw = 0.;
} else {
if (weights->isScalar() || weights->lengthOf() == 1) {
NDArray* temp_ptr = (*weights) / sum;
NDArray temp = *temp_ptr;
delete temp_ptr;
*dLdp *= temp;
*dLdl *= temp;
*dLdw = 0.;
} else {
NDArray* temp_ptr = (*weightsBroad) / sum;
NDArray temp = *temp_ptr;
delete temp_ptr;
dLdp->applyBroadcast(broadcast::Multiply, dimensions, &temp, dLdp);
dLdl->applyBroadcast(broadcast::Multiply, dimensions, &temp, dLdl);
if (weights != weightsBroad) {
std::vector<LongType> axesToReduceAlong =
ShapeUtils::evalBroadcastBackwardAxis(weights->shapeInfo(), weightsBroad->shapeInfo());
// Compute (E * sum - (E * weightsBroad).reduceNumber(Sum)) / (sum * sum)
NDArray* ETimesSum = E * sum;
NDArray* ETimesWeights = E * (*weightsBroad);
NDArray* ETimesWeightsSum = ETimesWeights->reduceNumber(reduce::Sum);
delete ETimesWeights;
NDArray* numerator = (*ETimesSum) - (*ETimesWeightsSum);
delete ETimesSum;
delete ETimesWeightsSum;
NDArray* sumSquared = sum * sum;
NDArray* result = (*numerator) / (*sumSquared);
delete numerator;
delete sumSquared;
result->reduceAlongDimension(reduce::Sum, dLdw, &axesToReduceAlong, true);
delete result;
} else {
// Compute (E * sum - (E * weightsBroad).reduceNumber(Sum)) / (sum * sum)
NDArray* ETimesSum = E * sum;
NDArray* ETimesWeights = E * (*weightsBroad);
NDArray* ETimesWeightsSum = ETimesWeights->reduceNumber(reduce::Sum);
delete ETimesWeights;
NDArray* numerator = (*ETimesSum) - (*ETimesWeightsSum);
delete ETimesSum;
delete ETimesWeightsSum;
NDArray* sumSquared = sum * sum;
NDArray* result = (*numerator) / (*sumSquared);
delete numerator;
delete sumSquared;
dLdw->assign(result);
delete result;
}
}
}
break;
}
case 3: { // 3 - "weighted_sum_by_nonzero_weights", output is scalar and equal to scalar sum of all elements of E
// array divided by number of non-zero weights
LongType numOfNonZeroWeights = 0;
if (weights->isScalar()) {
if (weights->e<double>(0) != 0.) numOfNonZeroWeights = E.lengthOf();
} else {
NDArray* countNonZero = weightsBroad->reduceNumber(reduce::CountNonZero);
numOfNonZeroWeights = countNonZero->e<LongType>(0);
delete countNonZero;
}
if (numOfNonZeroWeights == 0) {
*dLdp = 0.;
*dLdl = 0.;
*dLdw = 0.;
} else {
if (weights->isScalar() || weights->lengthOf() == 1) {
NDArray* temp_ptr = (*weights) / numOfNonZeroWeights;
NDArray temp = *temp_ptr;
delete temp_ptr;
*dLdp *= temp;
*dLdl *= temp;
NDArray* eSum = E.reduceNumber(reduce::Sum);
NDArray* result = (*eSum) / numOfNonZeroWeights;
delete eSum;
dLdw->assign(result);
delete result;
} else {
NDArray* temp_ptr = (*weightsBroad) / numOfNonZeroWeights;
NDArray temp = *temp_ptr;
delete temp_ptr;
dLdp->applyBroadcast(broadcast::Multiply, dimensions, &temp, dLdp);
dLdl->applyBroadcast(broadcast::Multiply, dimensions, &temp, dLdl);
if (weights != weightsBroad) {
std::vector<LongType> axesToReduceAlong =
ShapeUtils::evalBroadcastBackwardAxis(weights->shapeInfo(), weightsBroad->shapeInfo());
E.reduceAlongDimension(reduce::Sum, dLdw, &axesToReduceAlong, true);
*dLdw /= numOfNonZeroWeights;
} else {
NDArray* eDivNum = E / numOfNonZeroWeights;
dLdw->assign(eDivNum);
delete eDivNum;
}
}
}
break;
}
}
if (weightsBroad != weights) delete weightsBroad;
if (newLabels != cLabels) delete newLabels;
delete cLabels;
return Status::OK;
}
//////////////////////////////////////////////////////////////////////////
DECLARE_TYPES(softmax_cross_entropy_loss_grad) {
getOpDescriptor()
->setAllowedInputTypes(0, {ALL_FLOATS})
->setAllowedInputTypes(1, {ALL_FLOATS})
->setAllowedInputTypes(2, {ALL_FLOATS, ALL_INTS})
->setAllowedInputTypes(3, {ALL_FLOATS})
->setAllowedInputTypes(4, {ALL_FLOATS})
->setAllowedInputTypes(5, {ALL_FLOATS})
->setAllowedOutputTypes({ALL_FLOATS});
}
//////////////////////////////////////////////////////////////////////////
DECLARE_SHAPE_FN(softmax_cross_entropy_loss_grad) {
auto logitsShapeInfo = inputShape->at(0);
auto weightsShapeInfo = inputShape->at(1);
auto labelsShapeInfo = inputShape->at(2);
std::vector<LongType> dimensions = {-1};
// labels and logits must have the same shapes
REQUIRE_TRUE(shape::shapeEquals(logitsShapeInfo, labelsShapeInfo), 0,
"SOFTMAX_CROSS_ENTROPY_LOSS_GRAD OP: labels and logits arrays must have the same shapes, but got %s and "
"%s correspondingly!",
ShapeUtils::shapeAsString(labelsShapeInfo).c_str(), ShapeUtils::shapeAsString(logitsShapeInfo).c_str());
auto lossShapeInfo = ShapeUtils::evalReduceShapeInfo(shape::order(logitsShapeInfo), &dimensions, logitsShapeInfo,
false, false, block.getWorkspace());
// weights array can be single scalar or has the same rank as loss, and must be broadcastable to loss
REQUIRE_TRUE(shape::isScalar(weightsShapeInfo) || shape::rank(weightsShapeInfo) == shape::rank(lossShapeInfo), 0,
"SOFTMAX_CROSS_ENTROPY_LOSS_GRAD OP: weights array should be scalar or have the same rank as loss "
"array, but got %i and %i correspondingly!",
shape::rank(weightsShapeInfo), shape::rank(lossShapeInfo));
// check whether broadcast operation is possible for weights array
REQUIRE_TRUE(shape::isScalar(weightsShapeInfo) || ShapeUtils::areShapesBroadcastable(weightsShapeInfo, lossShapeInfo),
0,
"SOFTMAX_CROSS_ENTROPY_LOSS_GRAD OP: shapes of weights and loss arrays should be broadcastable, but got "
"weights = %s and loss = %s instead!",
ShapeUtils::shapeAsString(weightsShapeInfo).c_str(), ShapeUtils::shapeAsString(lossShapeInfo).c_str());
auto outType = DataTypeUtils::pickFloatingType(ArrayOptions::dataType(logitsShapeInfo));
auto dLdpShapeInfo = ConstantShapeHelper::getInstance().bufferForShapeInfo(outType, shape::order(logitsShapeInfo),
shape::rank(logitsShapeInfo),
shape::shapeOf(logitsShapeInfo))->primary();
auto dLdwShapeInfo = ConstantShapeHelper::getInstance().bufferForShapeInfo(outType, shape::order(weightsShapeInfo),
shape::rank(weightsShapeInfo),
shape::shapeOf(weightsShapeInfo))->primary();
auto dLdlShapeInfo = ConstantShapeHelper::getInstance().bufferForShapeInfo(outType, shape::order(labelsShapeInfo),
shape::rank(labelsShapeInfo),
shape::shapeOf(labelsShapeInfo))->primary();
return SHAPELIST(dLdpShapeInfo, dLdwShapeInfo, dLdlShapeInfo);
}
} // namespace ops
} // namespace sd
#endif