Merge the different LSTM EvalFloat/EvalHybrid calls into a single file.

PiperOrigin-RevId: 215870962

1 files changed, 909 insertions, 0 deletions

diff --git a/tensorflow/contrib/lite/kernels/lstm_eval.cc b/tensorflow/contrib/lite/kernels/lstm_eval.cc
new file mode 100644
index 0000000000..c6c21eb085
--- /dev/null
+++ b/tensorflow/contrib/lite/kernels/lstm_eval.cc
@@ -0,0 +1,909 @@
+/* Copyright 2018 The TensorFlow Authors. All Rights Reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://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.
+==============================================================================*/
+#include "tensorflow/contrib/lite/kernels/lstm_eval.h"
+
+#include <stdint.h>
+
+#include "tensorflow/contrib/lite/kernels/internal/kernel_utils.h"
+#include "tensorflow/contrib/lite/kernels/internal/tensor_utils.h"
+
+namespace tflite {
+namespace ops {
+namespace builtin {
+namespace lstm_eval {
+
+namespace {
+
+// Performs an LSTM batch inference step for input specified by input_ptr_batch.
+// The LSTM cell is specified by the pointers to its weights (*_weights_ptr) and
+// biases (*_bias_ptr), and buffers (*_scratch), along with additional
+// parameters:
+//  - params: various LSTM params including activation, clipping, etc.,
+//  - n_batch: size of batch,
+//  - n_cell: number of cells (or units),
+//  - n_input: the input size,
+//  - n_output: the output size.
+//
+// The pointers to the cell and output state and the output are updated.
+//
+// The pointers with the suffix "_batch" point to data aligned in batch_major
+// order, and each step processes batch_size many inputs from input_ptr_batch,
+// and updates batch_size many cell and output states.
+inline void LstmStepWithAuxInput(
+    const float* input_ptr_batch, const float* input_to_input_weights_ptr,
+    const float* input_to_forget_weights_ptr,
+    const float* input_to_cell_weights_ptr,
+    const float* input_to_output_weights_ptr, const float* aux_input_ptr_batch,
+    const float* aux_input_to_input_weights_ptr,
+    const float* aux_input_to_forget_weights_ptr,
+    const float* aux_input_to_cell_weights_ptr,
+    const float* aux_input_to_output_weights_ptr,
+    const float* recurrent_to_input_weights_ptr,
+    const float* recurrent_to_forget_weights_ptr,
+    const float* recurrent_to_cell_weights_ptr,
+    const float* recurrent_to_output_weights_ptr,
+    const float* cell_to_input_weights_ptr,
+    const float* cell_to_forget_weights_ptr,
+    const float* cell_to_output_weights_ptr, const float* input_gate_bias_ptr,
+    const float* forget_gate_bias_ptr, const float* cell_bias_ptr,
+    const float* output_gate_bias_ptr, const float* projection_weights_ptr,
+    const float* projection_bias_ptr, const TfLiteLSTMParams* params,
+    int n_batch, int n_cell, int n_input, int n_aux_input, int n_output,
+    float* output_state_ptr, float* cell_state_ptr, float* input_gate_scratch,
+    float* forget_gate_scratch, float* cell_scratch, float* output_gate_scratch,
+    float* output_ptr_batch) {
+  // Since we have already checked that weights are all there or none, we can
+  // check the existense of only one to the get the condition.
+  const bool use_cifg = (input_to_input_weights_ptr == nullptr);
+  const bool use_peephole = (cell_to_output_weights_ptr != nullptr);
+  // Initialize scratch buffers with bias.
+  if (!use_cifg) {
+    tensor_utils::VectorBatchVectorAssign(input_gate_bias_ptr, n_cell, n_batch,
+                                          input_gate_scratch);
+  }
+  tensor_utils::VectorBatchVectorAssign(forget_gate_bias_ptr, n_cell, n_batch,
+                                        forget_gate_scratch);
+  tensor_utils::VectorBatchVectorAssign(cell_bias_ptr, n_cell, n_batch,
+                                        cell_scratch);
+  tensor_utils::VectorBatchVectorAssign(output_gate_bias_ptr, n_cell, n_batch,
+                                        output_gate_scratch);
+
+  // For each batch and cell: compute input_weight * input.
+  if (!use_cifg) {
+    tensor_utils::MatrixBatchVectorMultiplyAccumulate(
+        input_to_input_weights_ptr, n_cell, n_input, input_ptr_batch, n_batch,
+        input_gate_scratch, /*result_stride=*/1);
+  }
+
+  tensor_utils::MatrixBatchVectorMultiplyAccumulate(
+      input_to_forget_weights_ptr, n_cell, n_input, input_ptr_batch, n_batch,
+      forget_gate_scratch, /*result_stride=*/1);
+  tensor_utils::MatrixBatchVectorMultiplyAccumulate(
+      input_to_cell_weights_ptr, n_cell, n_input, input_ptr_batch, n_batch,
+      cell_scratch, /*result_stride=*/1);
+  tensor_utils::MatrixBatchVectorMultiplyAccumulate(
+      input_to_output_weights_ptr, n_cell, n_input, input_ptr_batch, n_batch,
+      output_gate_scratch, /*result_stride=*/1);
+
+  // If auxiliary input is available then compute aux_input_weight * aux_input
+  if (aux_input_ptr_batch != nullptr) {
+    if (!use_cifg) {
+      tensor_utils::MatrixBatchVectorMultiplyAccumulate(
+          aux_input_to_input_weights_ptr, n_cell, n_aux_input,
+          aux_input_ptr_batch, n_batch, input_gate_scratch,
+          /*result_stride=*/1);
+    }
+
+    tensor_utils::MatrixBatchVectorMultiplyAccumulate(
+        aux_input_to_forget_weights_ptr, n_cell, n_aux_input,
+        aux_input_ptr_batch, n_batch, forget_gate_scratch, /*result_stride=*/1);
+    tensor_utils::MatrixBatchVectorMultiplyAccumulate(
+        aux_input_to_cell_weights_ptr, n_cell, n_aux_input, aux_input_ptr_batch,
+        n_batch, cell_scratch, /*result_stride=*/1);
+    tensor_utils::MatrixBatchVectorMultiplyAccumulate(
+        aux_input_to_output_weights_ptr, n_cell, n_aux_input,
+        aux_input_ptr_batch, n_batch, output_gate_scratch, /*result_stride=*/1);
+  }
+
+  // For each batch and cell: compute recurrent_weight * output_state.
+  if (!use_cifg) {
+    tensor_utils::MatrixBatchVectorMultiplyAccumulate(
+        recurrent_to_input_weights_ptr, n_cell, n_output, output_state_ptr,
+        n_batch, input_gate_scratch, /*result_stride=*/1);
+  }
+  tensor_utils::MatrixBatchVectorMultiplyAccumulate(
+      recurrent_to_forget_weights_ptr, n_cell, n_output, output_state_ptr,
+      n_batch, forget_gate_scratch,
+      /*result_stride=*/1);
+  tensor_utils::MatrixBatchVectorMultiplyAccumulate(
+      recurrent_to_cell_weights_ptr, n_cell, n_output, output_state_ptr,
+      n_batch, cell_scratch, /*result_stride=*/1);
+  tensor_utils::MatrixBatchVectorMultiplyAccumulate(
+      recurrent_to_output_weights_ptr, n_cell, n_output, output_state_ptr,
+      n_batch, output_gate_scratch,
+      /*result_stride=*/1);
+
+  // For each batch and cell: update input gate.
+  if (!use_cifg) {
+    if (use_peephole) {
+      tensor_utils::VectorBatchVectorCwiseProductAccumulate(
+          cell_to_input_weights_ptr, n_cell, cell_state_ptr, n_batch,
+          input_gate_scratch);
+    }
+    tensor_utils::ApplySigmoidToVector(input_gate_scratch, n_cell * n_batch,
+                                       input_gate_scratch);
+  }
+
+  // For each batch and cell: update forget gate.
+  if (use_peephole) {
+    tensor_utils::VectorBatchVectorCwiseProductAccumulate(
+        cell_to_forget_weights_ptr, n_cell, cell_state_ptr, n_batch,
+        forget_gate_scratch);
+  }
+  tensor_utils::ApplySigmoidToVector(forget_gate_scratch, n_cell * n_batch,
+                                     forget_gate_scratch);
+
+  // For each batch and cell: update the cell.
+  tensor_utils::VectorVectorCwiseProduct(forget_gate_scratch, cell_state_ptr,
+                                         n_batch * n_cell, cell_state_ptr);
+  tensor_utils::ApplyActivationToVector(cell_scratch, n_batch * n_cell,
+                                        params->activation, cell_scratch);
+  if (use_cifg) {
+    tensor_utils::Sub1Vector(forget_gate_scratch, n_batch * n_cell,
+                             forget_gate_scratch);
+    tensor_utils::VectorVectorCwiseProductAccumulate(
+        cell_scratch, forget_gate_scratch, n_batch * n_cell, cell_state_ptr);
+  } else {
+    tensor_utils::VectorVectorCwiseProductAccumulate(
+        cell_scratch, input_gate_scratch, n_batch * n_cell, cell_state_ptr);
+  }
+  if (params->cell_clip > 0.0) {
+    tensor_utils::ClipVector(cell_state_ptr, n_batch * n_cell,
+                             params->cell_clip, cell_state_ptr);
+  }
+
+  // For each batch and cell: update the output gate.
+  if (use_peephole) {
+    tensor_utils::VectorBatchVectorCwiseProductAccumulate(
+        cell_to_output_weights_ptr, n_cell, cell_state_ptr, n_batch,
+        output_gate_scratch);
+  }
+  tensor_utils::ApplySigmoidToVector(output_gate_scratch, n_batch * n_cell,
+                                     output_gate_scratch);
+  tensor_utils::ApplyActivationToVector(cell_state_ptr, n_batch * n_cell,
+                                        params->activation, cell_scratch);
+  tensor_utils::VectorVectorCwiseProduct(output_gate_scratch, cell_scratch,
+                                         n_batch * n_cell, output_gate_scratch);
+
+  // For each batch: update the projection and output_state.
+  const bool use_projection_weight = (projection_weights_ptr != nullptr);
+  const bool use_projection_bias = (projection_bias_ptr != nullptr);
+  if (use_projection_weight) {
+    if (use_projection_bias) {
+      tensor_utils::VectorBatchVectorAssign(projection_bias_ptr, n_output,
+                                            n_batch, output_ptr_batch);
+    } else {
+      tensor_utils::ZeroVector(output_ptr_batch, n_batch * n_output);
+    }
+    tensor_utils::MatrixBatchVectorMultiplyAccumulate(
+        projection_weights_ptr, n_output, n_cell, output_gate_scratch, n_batch,
+        output_ptr_batch, /*result_stride=*/1);
+    if (params->proj_clip > 0.0) {
+      tensor_utils::ClipVector(output_ptr_batch, n_batch * n_output,
+                               params->proj_clip, output_ptr_batch);
+    }
+  } else {
+    tensor_utils::CopyVector(output_gate_scratch, n_batch * n_output,
+                             output_ptr_batch);
+  }
+  tensor_utils::CopyVector(output_ptr_batch, n_batch * n_output,
+                           output_state_ptr);
+}
+
+// Same as above but with quantized weight matrices. In detail:
+// Input of size 'n_batch * n_input':
+//   input_ptr_batch
+//
+// LSTM weights:
+// Quantized input weights of size 'n_cell * n_input':
+//   input_to_input_weights            - optional (can be nullptr)
+//   input_to_forget_weights
+//   input_to_cell_weights
+//   input_to_input_weights
+// Quantized recurrent weights of size 'n_cell * n_output':
+//   recurrent_to_input_weights        - optional
+//   recurrent_to_forget_weights
+//   recurrent_to_cell_weights
+//   recurrent_to_input_weights
+// Quantized peephole weights of size 'n_cell', representing diagonal matrices.
+//   cell_to_input_weights             - optional
+//   cell_to_cell_weights              - optional
+//   cell_to_output_weights            - optional
+// Quantized projection weights of size 'n_output * n_cell'
+//   projection_weights_ptr            - optional
+// Weight scales (scalars) for each of the weights above.
+//   input_to_input_weights_scale      - optional
+//   input_to_forget_weights_scale
+//   input_to_cell_weights_scale
+//   input_to_output_weights_scale
+//   recurrent_to_input_weights_scale  - optional
+//   recurrent_to_forget_weights_scale
+//   recurrent_to_cell_weights_scale
+//   recurrent_to_output_weights_scale
+//   cell_to_input_weights_scale,
+//   cell_to_forget_weights_scale,
+//   cell_to_output_weights_scale,
+//   projection_weights_scale          - optional
+// Gate biases of size 'n_cell':
+//   input_gate_bias_ptr               - optional
+//   forget_gate_bias_ptr
+//   cell_gate_bias_ptr
+//   output_gate_bias_ptr
+//
+// Temporary pre-allocated storage for quantized values:
+//   quantized_input_ptr_batch (same size as input_ptr_batch)
+//   quantized_output_state_ptr (same size as output_state_ptr)
+//   quantized_cell_state_ptr (same size as cell_state_ptr)
+// Temporary pre-allocated storage for recovered values:
+//   recovered_cell_weights (same size as cell_to_*_weights)
+//
+// Outputs:
+//   output_state_ptr - size 'n_batch * n_output'
+//   cell_state_ptr   - size 'n_batch * n_cell'
+//   output_ptr_batch - size 'n_batch * n_output'
+inline void LstmStepWithAuxInput(
+    const float* input_ptr_batch, const int8_t* input_to_input_weights_ptr,
+    float input_to_input_weights_scale,
+    const int8_t* input_to_forget_weights_ptr,
+    float input_to_forget_weights_scale,
+    const int8_t* input_to_cell_weights_ptr, float input_to_cell_weights_scale,
+    const int8_t* input_to_output_weights_ptr,
+    float input_to_output_weights_scale, const float* aux_input_ptr_batch,
+    const int8_t* aux_input_to_input_weights_ptr,
+    float aux_input_to_input_weights_scale,
+    const int8_t* aux_input_to_forget_weights_ptr,
+    float aux_input_to_forget_weights_scale,
+    const int8_t* aux_input_to_cell_weights_ptr,
+    float aux_input_to_cell_weights_scale,
+    const int8_t* aux_input_to_output_weights_ptr,
+    float aux_input_to_output_weights_scale,
+    const int8_t* recurrent_to_input_weights_ptr,
+    float recurrent_to_input_weights_scale,
+    const int8_t* recurrent_to_forget_weights_ptr,
+    float recurrent_to_forget_weights_scale,
+    const int8_t* recurrent_to_cell_weights_ptr,
+    float recurrent_to_cell_weights_scale,
+    const int8_t* recurrent_to_output_weights_ptr,
+    float recurrent_to_output_weights_scale,
+    const int8_t* cell_to_input_weights_ptr, float cell_to_input_weights_scale,
+    const int8_t* cell_to_forget_weights_ptr,
+    float cell_to_forget_weights_scale,
+    const int8_t* cell_to_output_weights_ptr,
+    float cell_to_output_weights_scale, const float* input_gate_bias_ptr,
+    const float* forget_gate_bias_ptr, const float* cell_bias_ptr,
+    const float* output_gate_bias_ptr, const int8_t* projection_weights_ptr,
+    float projection_weights_scale, const float* projection_bias_ptr,
+    const TfLiteLSTMParams* params, int n_batch, int n_cell, int n_input,
+    int n_aux_input, int n_output, float* input_gate_scratch,
+    float* forget_gate_scratch, float* cell_scratch, float* output_gate_scratch,
+    float* scaling_factors, float* product_scaling_factors,
+    float* recovered_cell_weights, int8_t* quantized_input_ptr_batch,
+    int8_t* quantized_aux_input_ptr_batch, int8_t* quantized_output_state_ptr,
+    int8_t* quantized_cell_state_ptr, float* output_state_ptr,
+    float* cell_state_ptr, float* output_ptr_batch) {
+  // Since we have already checked that weights are all there or none, we
+  // can check the existense of only one to the get the condition.
+  const bool use_cifg = (input_to_input_weights_ptr == nullptr);
+  const bool use_peephole = (cell_to_output_weights_ptr != nullptr);
+  // Initialize scratch buffers with bias.
+  if (!use_cifg) {
+    tensor_utils::VectorBatchVectorAssign(input_gate_bias_ptr, n_cell, n_batch,
+                                          input_gate_scratch);
+  }
+  tensor_utils::VectorBatchVectorAssign(forget_gate_bias_ptr, n_cell, n_batch,
+                                        forget_gate_scratch);
+  tensor_utils::VectorBatchVectorAssign(cell_bias_ptr, n_cell, n_batch,
+                                        cell_scratch);
+  tensor_utils::VectorBatchVectorAssign(output_gate_bias_ptr, n_cell, n_batch,
+                                        output_gate_scratch);
+
+  if (!tensor_utils::IsZeroVector(input_ptr_batch, n_batch * n_input)) {
+    // Save quantization and matmul computation for all zero input.
+    float unused_min, unused_max;
+    for (int b = 0; b < n_batch; ++b) {
+      const int offset = b * n_input;
+      tensor_utils::SymmetricQuantizeFloats(
+          input_ptr_batch + offset, n_input, quantized_input_ptr_batch + offset,
+          &unused_min, &unused_max, &scaling_factors[b]);
+    }
+    // For each batch and cell: compute input_weight * input.
+    if (!use_cifg) {
+      for (int b = 0; b < n_batch; ++b) {
+        product_scaling_factors[b] =
+            scaling_factors[b] * input_to_input_weights_scale;
+      }
+      tensor_utils::MatrixBatchVectorMultiplyAccumulate(
+          input_to_input_weights_ptr, n_cell, n_input,
+          quantized_input_ptr_batch, product_scaling_factors, n_batch,
+          input_gate_scratch, /*result_stride=*/1);
+    }
+
+    for (int b = 0; b < n_batch; ++b) {
+      product_scaling_factors[b] =
+          scaling_factors[b] * input_to_forget_weights_scale;
+    }
+    tensor_utils::MatrixBatchVectorMultiplyAccumulate(
+        input_to_forget_weights_ptr, n_cell, n_input, quantized_input_ptr_batch,
+        product_scaling_factors, n_batch, forget_gate_scratch,
+        /*result_stride=*/1);
+
+    for (int b = 0; b < n_batch; ++b) {
+      product_scaling_factors[b] =
+          scaling_factors[b] * input_to_cell_weights_scale;
+    }
+    tensor_utils::MatrixBatchVectorMultiplyAccumulate(
+        input_to_cell_weights_ptr, n_cell, n_input, quantized_input_ptr_batch,
+        product_scaling_factors, n_batch, cell_scratch, /*result_stride=*/1);
+
+    for (int b = 0; b < n_batch; ++b) {
+      product_scaling_factors[b] =
+          scaling_factors[b] * input_to_output_weights_scale;
+    }
+    tensor_utils::MatrixBatchVectorMultiplyAccumulate(
+        input_to_output_weights_ptr, n_cell, n_input, quantized_input_ptr_batch,
+        product_scaling_factors, n_batch, output_gate_scratch,
+        /*result_stride=*/1);
+  }
+
+  if (aux_input_ptr_batch != nullptr &&
+      !tensor_utils::IsZeroVector(aux_input_ptr_batch, n_batch * n_input)) {
+    // Save quantization and matmul computation for all zero input.
+    float unused_min, unused_max;
+    for (int b = 0; b < n_batch; ++b) {
+      const int offset = b * n_input;
+      tensor_utils::SymmetricQuantizeFloats(
+          aux_input_ptr_batch + offset, n_input,
+          quantized_aux_input_ptr_batch + offset, &unused_min, &unused_max,
+          &scaling_factors[b]);
+    }
+    // For each batch and cell: compute input_weight * input.
+    if (!use_cifg) {
+      for (int b = 0; b < n_batch; ++b) {
+        product_scaling_factors[b] =
+            scaling_factors[b] * aux_input_to_input_weights_scale;
+      }
+      tensor_utils::MatrixBatchVectorMultiplyAccumulate(
+          aux_input_to_input_weights_ptr, n_cell, n_input,
+          quantized_aux_input_ptr_batch, product_scaling_factors, n_batch,
+          input_gate_scratch, /*result_stride=*/1);
+    }
+
+    for (int b = 0; b < n_batch; ++b) {
+      product_scaling_factors[b] =
+          scaling_factors[b] * aux_input_to_forget_weights_scale;
+    }
+    tensor_utils::MatrixBatchVectorMultiplyAccumulate(
+        aux_input_to_forget_weights_ptr, n_cell, n_input,
+        quantized_aux_input_ptr_batch, product_scaling_factors, n_batch,
+        forget_gate_scratch, /*result_stride=*/1);
+
+    for (int b = 0; b < n_batch; ++b) {
+      product_scaling_factors[b] =
+          scaling_factors[b] * aux_input_to_cell_weights_scale;
+    }
+    tensor_utils::MatrixBatchVectorMultiplyAccumulate(
+        aux_input_to_cell_weights_ptr, n_cell, n_input,
+        quantized_aux_input_ptr_batch, product_scaling_factors, n_batch,
+        cell_scratch, /*result_stride=*/1);
+
+    for (int b = 0; b < n_batch; ++b) {
+      product_scaling_factors[b] =
+          scaling_factors[b] * aux_input_to_output_weights_scale;
+    }
+    tensor_utils::MatrixBatchVectorMultiplyAccumulate(
+        aux_input_to_output_weights_ptr, n_cell, n_input,
+        quantized_aux_input_ptr_batch, product_scaling_factors, n_batch,
+        output_gate_scratch, /*result_stride=*/1);
+  }
+
+  if (!tensor_utils::IsZeroVector(output_state_ptr, n_batch * n_output)) {
+    // Save quantization and matmul computation for all zero input.
+    float unused_min, unused_max;
+    for (int b = 0; b < n_batch; ++b) {
+      const int offset = b * n_output;
+      tensor_utils::SymmetricQuantizeFloats(output_state_ptr + offset, n_output,
+                                            quantized_output_state_ptr + offset,
+                                            &unused_min, &unused_max,
+                                            &scaling_factors[b]);
+    }
+    // For each batch and cell: compute recurrent_weight * output_state.
+    if (!use_cifg) {
+      for (int b = 0; b < n_batch; ++b) {
+        product_scaling_factors[b] =
+            scaling_factors[b] * recurrent_to_input_weights_scale;
+      }
+      tensor_utils::MatrixBatchVectorMultiplyAccumulate(
+          recurrent_to_input_weights_ptr, n_cell, n_output,
+          quantized_output_state_ptr, product_scaling_factors, n_batch,
+          input_gate_scratch, /*result_stride=*/1);
+    }
+
+    for (int b = 0; b < n_batch; ++b) {
+      product_scaling_factors[b] =
+          scaling_factors[b] * recurrent_to_forget_weights_scale;
+    }
+    tensor_utils::MatrixBatchVectorMultiplyAccumulate(
+        recurrent_to_forget_weights_ptr, n_cell, n_output,
+        quantized_output_state_ptr, product_scaling_factors, n_batch,
+        forget_gate_scratch, /*result_stride=*/1);
+
+    for (int b = 0; b < n_batch; ++b) {
+      product_scaling_factors[b] =
+          scaling_factors[b] * recurrent_to_cell_weights_scale;
+    }
+    tensor_utils::MatrixBatchVectorMultiplyAccumulate(
+        recurrent_to_cell_weights_ptr, n_cell, n_output,
+        quantized_output_state_ptr, product_scaling_factors, n_batch,
+        cell_scratch, /*result_stride=*/1);
+
+    for (int b = 0; b < n_batch; ++b) {
+      product_scaling_factors[b] =
+          scaling_factors[b] * recurrent_to_output_weights_scale;
+    }
+    tensor_utils::MatrixBatchVectorMultiplyAccumulate(
+        recurrent_to_output_weights_ptr, n_cell, n_output,
+        quantized_output_state_ptr, product_scaling_factors, n_batch,
+        output_gate_scratch, /*result_stride=*/1);
+  }
+
+  // Save quantization and matmul computation for all zero input.
+  bool is_cell_state_all_zeros =
+      tensor_utils::IsZeroVector(cell_state_ptr, n_batch * n_cell);
+
+  // For each batch and cell: update input gate.
+  if (!use_cifg) {
+    if (use_peephole && !is_cell_state_all_zeros) {
+      tensor_utils::VectorScalarMultiply(cell_to_input_weights_ptr, n_cell,
+                                         cell_to_input_weights_scale,
+                                         recovered_cell_weights);
+      tensor_utils::VectorBatchVectorCwiseProductAccumulate(
+          recovered_cell_weights, n_cell, cell_state_ptr, n_batch,
+          input_gate_scratch);
+    }
+    tensor_utils::ApplySigmoidToVector(input_gate_scratch, n_cell * n_batch,
+                                       input_gate_scratch);
+  }
+
+  // For each batch and cell: update forget gate.
+  if (use_peephole && !is_cell_state_all_zeros) {
+    tensor_utils::VectorScalarMultiply(cell_to_forget_weights_ptr, n_cell,
+                                       cell_to_forget_weights_scale,
+                                       recovered_cell_weights);
+    tensor_utils::VectorBatchVectorCwiseProductAccumulate(
+        recovered_cell_weights, n_cell, cell_state_ptr, n_batch,
+        forget_gate_scratch);
+  }
+  tensor_utils::ApplySigmoidToVector(forget_gate_scratch, n_cell * n_batch,
+                                     forget_gate_scratch);
+
+  // For each batch and cell: update the cell.
+  tensor_utils::VectorVectorCwiseProduct(forget_gate_scratch, cell_state_ptr,
+                                         n_batch * n_cell, cell_state_ptr);
+  tensor_utils::ApplyActivationToVector(cell_scratch, n_batch * n_cell,
+                                        params->activation, cell_scratch);
+  if (use_cifg) {
+    tensor_utils::Sub1Vector(forget_gate_scratch, n_batch * n_cell,
+                             forget_gate_scratch);
+    tensor_utils::VectorVectorCwiseProductAccumulate(
+        cell_scratch, forget_gate_scratch, n_batch * n_cell, cell_state_ptr);
+  } else {
+    tensor_utils::VectorVectorCwiseProductAccumulate(
+        cell_scratch, input_gate_scratch, n_batch * n_cell, cell_state_ptr);
+  }
+  if (params->cell_clip > 0.0) {
+    tensor_utils::ClipVector(cell_state_ptr, n_batch * n_cell,
+                             params->cell_clip, cell_state_ptr);
+  }
+
+  is_cell_state_all_zeros =
+      tensor_utils::IsZeroVector(cell_state_ptr, n_batch * n_cell);
+  // For each batch and cell: update the output gate.
+  if (use_peephole && !is_cell_state_all_zeros) {
+    tensor_utils::VectorScalarMultiply(cell_to_output_weights_ptr, n_cell,
+                                       cell_to_output_weights_scale,
+                                       recovered_cell_weights);
+    tensor_utils::VectorBatchVectorCwiseProductAccumulate(
+        recovered_cell_weights, n_cell, cell_state_ptr, n_batch,
+        output_gate_scratch);
+  }
+  tensor_utils::ApplySigmoidToVector(output_gate_scratch, n_batch * n_cell,
+                                     output_gate_scratch);
+  tensor_utils::ApplyActivationToVector(cell_state_ptr, n_batch * n_cell,
+                                        params->activation, cell_scratch);
+  tensor_utils::VectorVectorCwiseProduct(output_gate_scratch, cell_scratch,
+                                         n_batch * n_cell, output_gate_scratch);
+
+  // For each batch: update the projection and output_state.
+  const bool use_projection_weight = (projection_weights_ptr != nullptr);
+  const bool use_projection_bias = (projection_bias_ptr != nullptr);
+  if (use_projection_weight) {
+    if (use_projection_bias) {
+      tensor_utils::VectorBatchVectorAssign(projection_bias_ptr, n_output,
+                                            n_batch, output_ptr_batch);
+    } else {
+      tensor_utils::ZeroVector(output_ptr_batch, n_batch * n_output);
+    }
+    if (!tensor_utils::IsZeroVector(output_gate_scratch, n_batch * n_cell)) {
+      // Save quantization and matmul computation for all zero input.
+      float unused_min, unused_max;
+      for (int b = 0; b < n_batch; ++b) {
+        const int offset = b * n_cell;
+        tensor_utils::SymmetricQuantizeFloats(
+            output_gate_scratch + offset, n_cell,
+            quantized_cell_state_ptr + offset, &unused_min, &unused_max,
+            &scaling_factors[b]);
+      }
+      for (int b = 0; b < n_batch; ++b) {
+        product_scaling_factors[b] =
+            scaling_factors[b] * projection_weights_scale;
+      }
+      tensor_utils::MatrixBatchVectorMultiplyAccumulate(
+          projection_weights_ptr, n_output, n_cell, quantized_cell_state_ptr,
+          product_scaling_factors, n_batch, output_ptr_batch,
+          /*result_stride=*/1);
+    }
+    if (params->proj_clip > 0.0) {
+      tensor_utils::ClipVector(output_ptr_batch, n_batch * n_output,
+                               params->proj_clip, output_ptr_batch);
+    }
+  } else {
+    tensor_utils::CopyVector(output_gate_scratch, n_batch * n_output,
+                             output_ptr_batch);
+  }
+  tensor_utils::CopyVector(output_ptr_batch, n_batch * n_output,
+                           output_state_ptr);
+}
+}  // namespace
+
+TfLiteStatus EvalFloat(
+    const TfLiteTensor* input, const TfLiteTensor* input_to_input_weights,
+    const TfLiteTensor* input_to_forget_weights,
+    const TfLiteTensor* input_to_cell_weights,
+    const TfLiteTensor* input_to_output_weights,
+    const TfLiteTensor* recurrent_to_input_weights,
+    const TfLiteTensor* recurrent_to_forget_weights,
+    const TfLiteTensor* recurrent_to_cell_weights,
+    const TfLiteTensor* recurrent_to_output_weights,
+    const TfLiteTensor* cell_to_input_weights,
+    const TfLiteTensor* cell_to_forget_weights,
+    const TfLiteTensor* cell_to_output_weights, const TfLiteTensor* aux_input,
+    const TfLiteTensor* aux_input_to_input_weights,
+    const TfLiteTensor* aux_input_to_forget_weights,
+    const TfLiteTensor* aux_input_to_cell_weights,
+    const TfLiteTensor* aux_input_to_output_weights,
+    const TfLiteTensor* input_gate_bias, const TfLiteTensor* forget_gate_bias,
+    const TfLiteTensor* cell_bias, const TfLiteTensor* output_gate_bias,
+    const TfLiteTensor* projection_weights, const TfLiteTensor* projection_bias,
+    const TfLiteLSTMParams* params, bool forward_sequence, int output_offset,
+    TfLiteTensor* scratch_buffer, TfLiteTensor* activation_state,
+    TfLiteTensor* cell_state, TfLiteTensor* output) {
+  const int max_time = (input->dims->size == 2) ? 1 : input->dims->data[0];
+  const int n_batch = input->dims->data[input->dims->size - 2];
+  const int n_input = input->dims->data[input->dims->size - 1];
+  const int aux_input_size =
+      (aux_input) ? aux_input->dims->data[aux_input->dims->size - 1] : 0;
+
+  // n_cell and n_output will be the same size when there is no projection.
+  const int n_cell = input_to_output_weights->dims->data[0];
+  const int n_output = recurrent_to_output_weights->dims->data[1];
+
+  // Since we have already checked that weights are all there or none, we can
+  // check the existense of only one to the get the condition.
+  const bool use_cifg = (input_to_input_weights == nullptr);
+  const bool use_peephole = (cell_to_output_weights != nullptr);
+
+  // Index the scratch buffers pointers to the global scratch buffer.
+  float* input_gate_scratch = nullptr;
+  float* cell_scratch = nullptr;
+  float* forget_gate_scratch = nullptr;
+  float* output_gate_scratch = nullptr;
+  if (use_cifg) {
+    cell_scratch = scratch_buffer->data.f;
+    forget_gate_scratch = scratch_buffer->data.f + n_cell * n_batch;
+    output_gate_scratch = scratch_buffer->data.f + 2 * n_cell * n_batch;
+  } else {
+    input_gate_scratch = scratch_buffer->data.f;
+    cell_scratch = scratch_buffer->data.f + n_cell * n_batch;
+    forget_gate_scratch = scratch_buffer->data.f + 2 * n_cell * n_batch;
+    output_gate_scratch = scratch_buffer->data.f + 3 * n_cell * n_batch;
+  }
+
+  // Check optional tensors, the respective pointers can be null.
+  const float* input_to_input_weights_ptr =
+      (use_cifg) ? nullptr : input_to_input_weights->data.f;
+  const float* recurrent_to_input_weights_ptr =
+      (use_cifg) ? nullptr : recurrent_to_input_weights->data.f;
+  const float* input_gate_bias_ptr =
+      (use_cifg) ? nullptr : input_gate_bias->data.f;
+  const float* cell_to_input_weights_ptr =
+      (use_peephole && !use_cifg) ? cell_to_input_weights->data.f : nullptr;
+  const float* cell_to_forget_weights_ptr =
+      (use_peephole) ? cell_to_forget_weights->data.f : nullptr;
+  const float* cell_to_output_weights_ptr =
+      (use_peephole) ? cell_to_output_weights->data.f : nullptr;
+  const float* projection_weights_ptr =
+      (projection_weights == nullptr) ? nullptr : projection_weights->data.f;
+  const float* projection_bias_ptr =
+      (projection_bias == nullptr) ? nullptr : projection_bias->data.f;
+
+  float* aux_input_ptr = nullptr;
+  float* aux_input_to_input_weights_ptr = nullptr;
+  float* aux_input_to_forget_weights_ptr = nullptr;
+  float* aux_input_to_cell_weights_ptr = nullptr;
+  float* aux_input_to_output_weights_ptr = nullptr;
+  if (aux_input_size > 0) {
+    aux_input_ptr = aux_input->data.f;
+    aux_input_to_input_weights_ptr = aux_input_to_input_weights->data.f;
+    aux_input_to_forget_weights_ptr = aux_input_to_forget_weights->data.f;
+    aux_input_to_cell_weights_ptr = aux_input_to_cell_weights->data.f;
+    aux_input_to_output_weights_ptr = aux_input_to_output_weights->data.f;
+  }
+
+  // Loop through the sequence.
+  const int input_step = n_batch * n_input;
+  const int output_step = n_batch * output->dims->data[output->dims->size - 1];
+  for (int t = 0; t < max_time; t++) {
+    // If this is the forward_sequence, step forward, otherwise step backwards.
+    const int t_rel = forward_sequence ? t : max_time - t - 1;
+    const float* input_ptr = input->data.f + t_rel * input_step;
+    float* output_ptr_time =
+        output->data.f + t_rel * output_step + output_offset;
+
+    LstmStepWithAuxInput(
+        input_ptr, input_to_input_weights_ptr, input_to_forget_weights->data.f,
+        input_to_cell_weights->data.f, input_to_output_weights->data.f,
+        aux_input_ptr, aux_input_to_input_weights_ptr,
+        aux_input_to_forget_weights_ptr, aux_input_to_cell_weights_ptr,
+        aux_input_to_output_weights_ptr, recurrent_to_input_weights_ptr,
+        recurrent_to_forget_weights->data.f, recurrent_to_cell_weights->data.f,
+        recurrent_to_output_weights->data.f, cell_to_input_weights_ptr,
+        cell_to_forget_weights_ptr, cell_to_output_weights_ptr,
+        input_gate_bias_ptr, forget_gate_bias->data.f, cell_bias->data.f,
+        output_gate_bias->data.f, projection_weights_ptr, projection_bias_ptr,
+        params, n_batch, n_cell, n_input, aux_input_size, n_output,
+        activation_state->data.f, cell_state->data.f, input_gate_scratch,
+        forget_gate_scratch, cell_scratch, output_gate_scratch,
+        output_ptr_time);
+  }
+  return kTfLiteOk;
+}
+
+TfLiteStatus EvalHybrid(
+    const TfLiteTensor* input, const TfLiteTensor* input_to_input_weights,
+    const TfLiteTensor* input_to_forget_weights,
+    const TfLiteTensor* input_to_cell_weights,
+    const TfLiteTensor* input_to_output_weights,
+    const TfLiteTensor* recurrent_to_input_weights,
+    const TfLiteTensor* recurrent_to_forget_weights,
+    const TfLiteTensor* recurrent_to_cell_weights,
+    const TfLiteTensor* recurrent_to_output_weights,
+    const TfLiteTensor* cell_to_input_weights,
+    const TfLiteTensor* cell_to_forget_weights,
+    const TfLiteTensor* cell_to_output_weights, const TfLiteTensor* aux_input,
+    const TfLiteTensor* aux_input_to_input_weights,
+    const TfLiteTensor* aux_input_to_forget_weights,
+    const TfLiteTensor* aux_input_to_cell_weights,
+    const TfLiteTensor* aux_input_to_output_weights,
+    const TfLiteTensor* input_gate_bias, const TfLiteTensor* forget_gate_bias,
+    const TfLiteTensor* cell_bias, const TfLiteTensor* output_gate_bias,
+    const TfLiteTensor* projection_weights, const TfLiteTensor* projection_bias,
+    const TfLiteLSTMParams* params, bool forward_sequence, int output_offset,
+    TfLiteTensor* scratch_buffer, TfLiteTensor* scaling_factors,
+    TfLiteTensor* prod_scaling_factors, TfLiteTensor* recovered_cell_weights,
+    TfLiteTensor* input_quantized, TfLiteTensor* aux_input_quantized,
+    TfLiteTensor* output_state_quantized, TfLiteTensor* cell_state_quantized,
+    TfLiteTensor* output_state, TfLiteTensor* cell_state,
+    TfLiteTensor* output) {
+  const int max_time = (input->dims->size == 2) ? 1 : input->dims->data[0];
+  const int n_batch = input->dims->data[input->dims->size - 2];
+  const int n_input = input->dims->data[input->dims->size - 1];
+  const int aux_input_size =
+      (aux_input) ? aux_input->dims->data[aux_input->dims->size - 1] : 0;
+  // n_cell and n_output will be the same size when there is no projection.
+  const int n_cell = input_to_output_weights->dims->data[0];
+  const int n_output = recurrent_to_output_weights->dims->data[1];
+
+  // Since we have already checked that weights are all there or none, we can
+  // check the existence of only one to get the condition.
+  const bool use_cifg = (input_to_input_weights == nullptr);
+  const bool use_peephole = (cell_to_output_weights != nullptr);
+
+  float* input_gate_scratch = nullptr;
+  float* cell_scratch = nullptr;
+  float* forget_gate_scratch = nullptr;
+  float* output_gate_scratch = nullptr;
+  if (use_cifg) {
+    cell_scratch = scratch_buffer->data.f;
+    forget_gate_scratch = scratch_buffer->data.f + n_cell * n_batch;
+    output_gate_scratch = scratch_buffer->data.f + 2 * n_cell * n_batch;
+  } else {
+    input_gate_scratch = scratch_buffer->data.f;
+    cell_scratch = scratch_buffer->data.f + n_cell * n_batch;
+    forget_gate_scratch = scratch_buffer->data.f + 2 * n_cell * n_batch;
+    output_gate_scratch = scratch_buffer->data.f + 3 * n_cell * n_batch;
+  }
+
+  // Check optional tensors, the respective pointers can be null.
+  int8_t* input_to_input_weights_ptr = nullptr;
+  float input_to_input_weights_scale = 1.0f;
+  int8_t* recurrent_to_input_weights_ptr = nullptr;
+  float recurrent_to_input_weights_scale = 1.0f;
+  float* input_gate_bias_ptr = nullptr;
+  if (!use_cifg) {
+    input_to_input_weights_ptr =
+        reinterpret_cast<int8_t*>(input_to_input_weights->data.uint8);
+    recurrent_to_input_weights_ptr =
+        reinterpret_cast<int8_t*>(recurrent_to_input_weights->data.uint8);
+    input_gate_bias_ptr = input_gate_bias->data.f;
+    input_to_input_weights_scale = input_to_input_weights->params.scale;
+    recurrent_to_input_weights_scale = recurrent_to_input_weights->params.scale;
+  }
+
+  int8_t* cell_to_input_weights_ptr = nullptr;
+  int8_t* cell_to_forget_weights_ptr = nullptr;
+  int8_t* cell_to_output_weights_ptr = nullptr;
+  float cell_to_input_weights_scale = 1.0f;
+  float cell_to_forget_weights_scale = 1.0f;
+  float cell_to_output_weights_scale = 1.0f;
+  if (use_peephole) {
+    if (!use_cifg) {
+      cell_to_input_weights_ptr =
+          reinterpret_cast<int8_t*>(cell_to_input_weights->data.uint8);
+      cell_to_input_weights_scale = cell_to_input_weights->params.scale;
+    }
+    cell_to_forget_weights_ptr =
+        reinterpret_cast<int8_t*>(cell_to_forget_weights->data.uint8);
+    cell_to_output_weights_ptr =
+        reinterpret_cast<int8_t*>(cell_to_output_weights->data.uint8);
+    cell_to_forget_weights_scale = cell_to_forget_weights->params.scale;
+    cell_to_output_weights_scale = cell_to_output_weights->params.scale;
+  }
+
+  const int8_t* projection_weights_ptr =
+      (projection_weights == nullptr)
+          ? nullptr
+          : reinterpret_cast<int8_t*>(projection_weights->data.uint8);
+  const float projection_weights_scale =
+      (projection_weights == nullptr) ? 1.0f : projection_weights->params.scale;
+  const float* projection_bias_ptr =
+      (projection_bias == nullptr) ? nullptr : projection_bias->data.f;
+
+  // Required tensors, pointers are non-null.
+  const int8_t* input_to_forget_weights_ptr =
+      reinterpret_cast<int8_t*>(input_to_forget_weights->data.uint8);
+  const float input_to_forget_weights_scale =
+      input_to_forget_weights->params.scale;
+  const int8_t* input_to_cell_weights_ptr =
+      reinterpret_cast<int8_t*>(input_to_cell_weights->data.uint8);
+  const float input_to_cell_weights_scale = input_to_cell_weights->params.scale;
+  const int8_t* input_to_output_weights_ptr =
+      reinterpret_cast<int8_t*>(input_to_output_weights->data.uint8);
+  const float input_to_output_weights_scale =
+      input_to_output_weights->params.scale;
+  const int8_t* recurrent_to_forget_weights_ptr =
+      reinterpret_cast<int8_t*>(recurrent_to_forget_weights->data.uint8);
+  const float recurrent_to_forget_weights_scale =
+      recurrent_to_forget_weights->params.scale;
+  const int8_t* recurrent_to_cell_weights_ptr =
+      reinterpret_cast<int8_t*>(recurrent_to_cell_weights->data.uint8);
+  const float recurrent_to_cell_weights_scale =
+      recurrent_to_cell_weights->params.scale;
+  const int8_t* recurrent_to_output_weights_ptr =
+      reinterpret_cast<int8_t*>(recurrent_to_output_weights->data.uint8);
+  const float recurrent_to_output_weights_scale =
+      recurrent_to_output_weights->params.scale;
+  const float* forget_gate_bias_ptr = forget_gate_bias->data.f;
+  const float* cell_bias_ptr = cell_bias->data.f;
+  const float* output_gate_bias_ptr = output_gate_bias->data.f;
+
+  float* output_state_ptr = output_state->data.f;
+  float* cell_state_ptr = cell_state->data.f;
+
+  // Temporary storage for quantized values and scaling factors.
+  int8_t* quantized_input_ptr =
+      reinterpret_cast<int8_t*>(input_quantized->data.uint8);
+  int8_t* quantized_aux_input_ptr =
+      (aux_input_quantized == nullptr)
+          ? nullptr
+          : reinterpret_cast<int8_t*>(aux_input_quantized->data.uint8);
+  int8_t* quantized_output_state_ptr =
+      reinterpret_cast<int8_t*>(output_state_quantized->data.uint8);
+  int8_t* quantized_cell_state_ptr =
+      reinterpret_cast<int8_t*>(cell_state_quantized->data.uint8);
+  float* scaling_factors_ptr = scaling_factors->data.f;
+  float* prod_scaling_factors_ptr = prod_scaling_factors->data.f;
+  float* recovered_cell_weights_ptr = recovered_cell_weights->data.f;
+
+  // Auxiliary input and weights.
+  float* aux_input_ptr = nullptr;
+  int8_t* aux_input_to_input_weights_ptr = nullptr;
+  int8_t* aux_input_to_forget_weights_ptr = nullptr;
+  int8_t* aux_input_to_cell_weights_ptr = nullptr;
+  int8_t* aux_input_to_output_weights_ptr = nullptr;
+  float aux_input_to_input_weights_scale = 0.0f;
+  float aux_input_to_forget_weights_scale = 0.0f;
+  float aux_input_to_cell_weights_scale = 0.0f;
+  float aux_input_to_output_weights_scale = 0.0f;
+  if (aux_input_size > 0) {
+    aux_input_ptr = aux_input->data.f;
+    aux_input_to_input_weights_ptr =
+        reinterpret_cast<int8_t*>(aux_input_to_input_weights->data.uint8);
+    aux_input_to_forget_weights_ptr =
+        reinterpret_cast<int8_t*>(aux_input_to_forget_weights->data.uint8);
+    aux_input_to_cell_weights_ptr =
+        reinterpret_cast<int8_t*>(aux_input_to_cell_weights->data.uint8);
+    aux_input_to_output_weights_ptr =
+        reinterpret_cast<int8_t*>(aux_input_to_output_weights->data.uint8);
+    aux_input_to_input_weights_scale = aux_input_to_input_weights->params.scale;
+    aux_input_to_forget_weights_scale =
+        aux_input_to_forget_weights->params.scale;
+    aux_input_to_cell_weights_scale = aux_input_to_cell_weights->params.scale;
+    aux_input_to_output_weights_scale =
+        aux_input_to_output_weights->params.scale;
+  }
+
+  // Feed the sequence into the LSTM step-by-step.
+  const int input_step = n_batch * n_input;
+  const int output_step = n_batch * output->dims->data[output->dims->size - 1];
+  for (int t = 0; t < max_time; t++) {
+    // If this is the forward_sequence, step forward, otherwise step backwards.
+    const int t_rel = forward_sequence ? t : max_time - t - 1;
+    const float* input_ptr = input->data.f + t_rel * input_step;
+    float* output_ptr = output->data.f + t_rel * output_step + output_offset;
+
+    LstmStepWithAuxInput(
+        input_ptr, input_to_input_weights_ptr, input_to_input_weights_scale,
+        input_to_forget_weights_ptr, input_to_forget_weights_scale,
+        input_to_cell_weights_ptr, input_to_cell_weights_scale,
+        input_to_output_weights_ptr, input_to_output_weights_scale,
+        aux_input_ptr, aux_input_to_input_weights_ptr,
+        aux_input_to_input_weights_scale, aux_input_to_forget_weights_ptr,
+        aux_input_to_forget_weights_scale, aux_input_to_cell_weights_ptr,
+        aux_input_to_cell_weights_scale, aux_input_to_output_weights_ptr,
+        aux_input_to_output_weights_scale, recurrent_to_input_weights_ptr,
+        recurrent_to_input_weights_scale, recurrent_to_forget_weights_ptr,
+        recurrent_to_forget_weights_scale, recurrent_to_cell_weights_ptr,
+        recurrent_to_cell_weights_scale, recurrent_to_output_weights_ptr,
+        recurrent_to_output_weights_scale, cell_to_input_weights_ptr,
+        cell_to_input_weights_scale, cell_to_forget_weights_ptr,
+        cell_to_forget_weights_scale, cell_to_output_weights_ptr,
+        cell_to_output_weights_scale, input_gate_bias_ptr, forget_gate_bias_ptr,
+        cell_bias_ptr, output_gate_bias_ptr, projection_weights_ptr,
+        projection_weights_scale, projection_bias_ptr, params, n_batch, n_cell,
+        n_input, aux_input_size, n_output, input_gate_scratch,
+        forget_gate_scratch, cell_scratch, output_gate_scratch,
+        scaling_factors_ptr, prod_scaling_factors_ptr,
+        recovered_cell_weights_ptr, quantized_input_ptr,
+        quantized_aux_input_ptr, quantized_output_state_ptr,
+        quantized_cell_state_ptr, output_state_ptr, cell_state_ptr, output_ptr);
+  }
+
+  return kTfLiteOk;
+}
+
+}  // namespace lstm_eval
+}  // namespace builtin
+}  // namespace ops
+}  // namespace tflite