feat(): finished logic for LSTM cell, now to test

Signed-off-by: Abhiram Iyer <abhirami@nvidia.com>

Signed-off-by: Abhiram Iyer <abhi.iyer.ai@gmail.com>

Author: abhi-iyer

core/conversion/converters/impl/lstm_cell.cpp

@@ -99,16 +99,57 @@ auto lstm_cell_registrations TRTORCH_UNUSED = RegisterNodeConversionPatterns()
             TRTORCH_CHECK(add3, "Unable to create ElementWise layer from node: " << *n);
             auto add3_out = add3->getOutput(0);
 
-            
-
-
-
-            auto mm_layer = ctx->net->addMatrixMultiply(*self, nvinfer1::MatrixOperation::kNONE, *other, nvinfer1::MatrixOperation::kNONE);
-            TRTORCH_CHECK(mm_layer, "Unable to create matrix multiplication node: " << *n);
-            mm_layer->setName(util::node_info(n).c_str());
-            auto out_tensor = ctx->AssociateValueAndTensor(n->outputs()[0], mm_layer->getOutput(0));
+            // chunk Tensor into 4 parts and apply activation functions
+            auto dims = util::toVec(add3_out->getDimensions());
+            auto batch = dims[0];
+            auto hidden = dims[1]/4;
+
+            auto size = util::toDims(std::vector<int64_t>({batch, hidden}));
+            auto stride = util::toDims(std::vector<int64_t>({1, 1}));
+
+            auto slice1 = ctx->net->addSlice(*add3_out, util::toDims(std::vector<int64_t>({0, 0})), size, stride);
+            TRTORCH_CHECK(slice1, "Unable to create Slice layer from node: " << *n);
+            auto activ1 = ctx->net->addActivation(*slice1->getOutput(0), nvinfer1::ActivationType::kSIGMOID);
+            TRTORCH_CHECK(activ1, "Unable to create sigmoid activation layer from node: " << *n);
+            auto ingate = activ1->getOutput(0);
+
+            auto slice2 = ctx->net->addSlice(*add3_out, util::toDims(std::vector<int64_t>({0, hidden})), size, stride);
+            TRTORCH_CHECK(slice2, "Unable to create Slice layer from node: " << *n);
+            auto activ2 = ctx->net->addActivation(*slice2->getOutput(0), nvinfer1::ActivationType::kSIGMOID);
+            TRTORCH_CHECK(activ2, "Unable to create sigmoid activation layer from node: " << *n);
+            auto forgetgate = activ2->getOutput(0);
+
+            auto slice3 = ctx->net->addSlice(*add3_out, util::toDims(std::vector<int64_t>({0, 2*hidden})), size, stride);
+            TRTORCH_CHECK(slice3, "Unable to create Slice layer from node: " << *n);
+            auto activ3 = ctx->net->addActivation(*slice3->getOutput(0), nvinfer1::ActivationType::kTANH);
+            TRTORCH_CHECK(activ3, "Unable to create tanh activation layer from node: " << *n);
+            auto cellgate = activ3->getOutput(0);
+
+            auto slice4 = ctx->net->addSlice(*add3_out, util::toDims(std::vector<int64_t>({0, 3*hidden})), size, stride);
+            TRTORCH_CHECK(slice4, "Unable to create Slice layer from node: " << *n);
+            auto activ4 = ctx->net->addActivation(*slice4->getOutput(0), nvinfer1::ActivationType::kSIGMOID);
+            TRTORCH_CHECK(activ4, "Unable to create sigmoid activation layer from node: " << *n);
+            auto outgate = activ4->getOutput(0);
+
+            // compute cy
+            auto forget_cx = ctx->net->addElementWise(*forgetgate, *state[1], nvinfer1::ElementWiseOperation::kPROD);
+            TRTORCH_CHECK(forget_cx, "Unable to create ElementWise layer from node: " << *n);
+            auto in_cell = ctx->net->addElementWise(*ingate, *cellgate, nvinfer1::ElementWiseOperation::kPROD);
+            TRTORCH_CHECK(in_cell, "Unable to create ElementWise layer from node: " << *n);
+            auto cy = ctx->net->addElementWise(*forget_cx->getOutput(0), *in_cell->getOutput(0), nvinfer1::ElementWiseOperation::kPROD);
+            TRTORCH_CHECK(cy, "Unable to create ElementWise layer from node: " << *n);
+            auto cy_out = ctx->AssociateValueAndTensor(n->outputs()[1], cy->getOutput(0));
+
+            // compute hy
+            auto cy_tanh = ctx->net->addActivation(*cy_out, nvinfer1::ActivationType::kTANH);
+            TRTORCH_CHECK(cy_tanh, "Unable to create tanh activation layer from node: " << *n);
+            auto hy = ctx->net->addElementWise(*outgate, *cy_tanh->getOutput(0), nvinfer1::ElementWiseOperation::kPROD);
+            TRTORCH_CHECK(hy, "Unable to create ElementWise layer from node: " << *n);
+            auto hy_out = ctx->AssociateValueAndTensor(n->outputs()[0], hy->getOutput(0));
+
+            LOG_DEBUG("Output tensor [hy] shape: " << hy_out->getDimensions());
+            LOG_DEBUG("Output tensor [cy] shape: " << cy_out->getDimensions());
 
-            LOG_DEBUG("Output tensor shape: " << out_tensor->getDimensions());
             return true;
     }
   });