text: /*
   *  ******************************************************************************
   *  *
   *  *
   *  * 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 Alex Black
  //
  
  #include <system/op_boilerplate.h>
  #if NOT_EXCLUDED(OP_lstmBlockCell)
  
  #include <ops/declarable/CustomOperations.h>
  #include <ops/declarable/helpers/lstmBlock.h>
  
  namespace sd {
  namespace ops {
  
  //////////////////////////////////////////////////////////////////////////
  CUSTOM_OP_IMPL(lstmBlockCell, 8, 7, false, 2, 1) {
    // Notation: mostly following https://arxiv.org/pdf/1503.04069.pdf
    auto xt = INPUT_VARIABLE(0);     // input [bS, inSize] at time t
    auto cLast = INPUT_VARIABLE(1);  // previous cell state  [bS, numUnits], time t-1
    auto yLast = INPUT_VARIABLE(2);  // previous output [bS, numUnits], time t-1
  
    auto W = INPUT_VARIABLE(3);    // Weights - concatenated (input-to-hidden, hidden-to-hidden weights)  weights,
                                   // [(inSize+numUnits), 4*numUnits]
    auto Wci = INPUT_VARIABLE(4);  // weights - cell peephole (t-1) connections to input modulation gate, [numUnits]
    auto Wcf = INPUT_VARIABLE(5);  // weights - cell peephole (t-1) connections to forget gate, [numUnits]
    auto Wco = INPUT_VARIABLE(6);  // weights - cell peephole (t) connections to output gate, [numUnits]
    auto b = INPUT_VARIABLE(7);    // biases, [4*numUnits]
  
    auto i = OUTPUT_VARIABLE(0);  // Output - input modulation gate activations [bS, numUnits]
    auto c = OUTPUT_VARIABLE(1);  // Activations, cell state (pre tanh) [bs, numUnits]
    auto f = OUTPUT_VARIABLE(2);  // Output - forget gate activations [bs, numUnits]
    auto o = OUTPUT_VARIABLE(3);  // Output - output gate activations [bs, numUnits]
    auto z = OUTPUT_VARIABLE(4);  // Output - input gate activations [bs, numUnits]
    auto h = OUTPUT_VARIABLE(5);  // Cell state, post tanh [bs, numUnits]
    auto y = OUTPUT_VARIABLE(6);  // current cell output [bS, numProj], time t
  
    const int peephole = INT_ARG(0);  // if 1, provide peephole connections
  
    const double forgetBias = T_ARG(0);
    const double clippingCellValue = T_ARG(1);
    // clipping value for ct, if it is not equal to zero, then cell state is clipped
  
    REQUIRE_TRUE(xt->rankOf() == 2 && cLast->rankOf() == 2 && yLast->rankOf() == 2, 0,
                 "lstmBlockCell: Input ranks must be 2 for inputs 0/1/2 (x, cLast, outLast) - got %i, %i, %i",
                 xt->rankOf(), cLast->rankOf(), yLast->rankOf());
    const int rank = xt->rankOf();
    const int bS = xt->sizeAt(0);
    const int inSize = xt->sizeAt(1);
    const int numUnits = cLast->sizeAt(1);
  
    REQUIRE_TRUE(xt->sizeAt(0) == yLast->sizeAt(0) && xt->sizeAt(0) == cLast->sizeAt(0), 0,
                 "lstmBlockCell: Input minibatch sizes (dimension 0) must be same for xt, cLast, yLast");
    REQUIRE_TRUE(W->rankOf() == 2, 0, "lstmBlockCell: Weights array rank must be 2");
    REQUIRE_TRUE(W->sizeAt(0) == (inSize + numUnits), 0,
                 "lstmBlockCell: Weights size(0) must be equal to inSize + numUnits, got %i", W->sizeAt(0));
    REQUIRE_TRUE(W->sizeAt(1) == (4 * numUnits), 0, "lstmBlockCell: Weights size(1) must be equal to 4*numUnits, got %i",
                 W->sizeAt(1));
    REQUIRE_TRUE(b->rankOf() == 1 && b->sizeAt(0) == (4 * numUnits), 0,
                 "lstmBlockCell: Biases must be rank 1, size 4*numUnits");
    REQUIRE_TRUE(i->rankOf() == 2 && c->rankOf() == 2 && f->rankOf() == 2 && o->rankOf() == 2 && z->rankOf() == 2 &&
                     h->rankOf() == 2 && y->rankOf() == 2 && i->sizeAt(0) == bS && c->sizeAt(0) == bS &&
                     f->sizeAt(0) == bS && o->sizeAt(0) == bS && z->sizeAt(0) == bS && h->sizeAt(0) == bS &&
                     y->sizeAt(0) == bS && i->sizeAt(1) == numUnits && c->sizeAt(1) == numUnits &&
                     f->sizeAt(1) == numUnits && o->sizeAt(1) == numUnits && z->sizeAt(1) == numUnits &&
                     h->sizeAt(1) == numUnits && y->sizeAt(1) == numUnits,
                 0, "lstmBlockCell: Output arrays must all be rank 2 with size(0) == batchSize and size(1) == numUnits");
  
    // calculations
    helpers::lstmBlockCell(xt, cLast, yLast, W, Wci, Wcf, Wco, b, i, c, f, o, z, h, y,
                           {(double)peephole, forgetBias, clippingCellValue});
  
    return sd::Status::OK;
  }
  
  DECLARE_TYPES(lstmBlockCell) {
    getOpDescriptor()->setAllowedInputTypes(sd::DataType::ANY)->setAllowedOutputTypes({ALL_FLOATS});
  }
  
  DECLARE_SHAPE_FN(lstmBlockCell) {
    auto xt = inputShape->at(0);     // input [bS, inSize] at time t
    auto cLast = inputShape->at(1);  // previous cell state  [bS, numUnits], time t-1
    auto yLast = inputShape->at(2);  // previous output [bS, numUnits], time t-1
  
    auto W = inputShape->at(3);    // Weights - concatenated (input-to-hidden, hidden-to-hidden weights)  weights,
                                   // [(inSize+numUnits), 4*numUnits]
    auto Wci = inputShape->at(4);  // weights - cell peephole (t-1) connections to input modulation gate, [numUnits]
    auto Wcf = inputShape->at(5);  // weights - cell peephole (t-1) connections to forget gate, [numUnits]
    auto Wco = inputShape->at(6);  // weights - cell peephole (t) connections to output gate, [numUnits]
    auto b = inputShape->at(7);    // biases, [4*numUnits]
  
    REQUIRE_TRUE(shape::rank(xt) == 2 && shape::rank(cLast) == 2 && shape::rank(yLast) == 2, 0,
                 "lstmBlockCell: Input ranks must be 2 for inputs 0/1/2 (x, cLast, outLast) - got %i, %i, %i",
                 shape::rank(xt), shape::rank(cLast), shape::rank(yLast));
    const int inSize = xt[2];
    const int numUnits = cLast[2];  //[rank, bS, nOut, ...]
    REQUIRE_TRUE(xt[1] == yLast[1] && xt[1] == cLast[1], 0,
                 "lstmBlockCell: Input minibatch sizes (dimension 0) must be same for xt, cLast, yLast");
    REQUIRE_TRUE(shape::rank(W) == 2, 0, "lstmBlockCell: Weights array rank must be rank 2, got %i", shape::rank(W));
    REQUIRE_TRUE(W[1] == (inSize + numUnits), 0,
                 "lstmBlockCell: Weights size(0) must be equal to inSize + numUnits, got %i", W[1]);
    REQUIRE_TRUE(W[2] == (4 * numUnits), 0, "lstmBlockCell: Weights size(1) must be equal to 4*numUnits, got %i", W[2]);
    REQUIRE_TRUE(shape::rank(b) == 1 && b[1] == (4 * numUnits), 0,
                 "lstmBlockCell: Biases must be rank 1, size 4*numUnits");
  
    // evaluate output shapeInfos
    const int bS = xt[1];
    sd::LongType *s(nullptr);
    ALLOCATE(s, block.getWorkspace(), shape::shapeInfoLength(2), sd::LongType);  // [bS, numUnits]
  
    s[0] = 2;
    s[1] = bS;
    s[2] = numUnits;
  
    ShapeUtils::updateStridesAndType(s, xt, 'c');
  
    auto s1 = CONSTANT(s);
  
    // 7 outputs, all same shape: z, i, f, o, h, c, y
    return SHAPELIST(s1, s1, s1, s1, s1, s1, s1);
  }
  
  }  // namespace ops
  }  // namespace sd
  
  #endif
  