text: // Copyright 2020 Google LLC
  //
  // This source code is licensed under the BSD-style license found in the
  // LICENSE file in the root directory of this source tree.
  
  #include <math.h>
  #include <stddef.h>
  #include <stdint.h>
  
  #include <xnnpack.h>
  #include <xnnpack/log.h>
  #include <xnnpack/params.h>
  #include <xnnpack/subgraph.h>
  
  
  static enum xnn_status create_clamp_operator(
    const struct xnn_node* node,
    const struct xnn_value* values,
    size_t num_values,
    struct xnn_operator_data* opdata,
    struct xnn_code_cache* code_cache)
  {
    assert(node->num_inputs == 1);
    const uint32_t input_id = node->inputs[0];
    assert(input_id != XNN_INVALID_VALUE_ID);
    assert(input_id < num_values);
  
    assert(node->num_outputs == 1);
    const uint32_t output_id = node->outputs[0];
    assert(output_id != XNN_INVALID_VALUE_ID);
    assert(output_id < num_values);
  
    const size_t num_input_dims = values[input_id].shape.num_dims;
    const size_t channel_dim = num_input_dims == 0 ? 1 : values[input_id].shape.dim[num_input_dims - 1];
  
    enum xnn_status status;
    switch (node->compute_type) {
  #ifndef XNN_NO_F16_OPERATORS
      case xnn_compute_type_fp16:
        status = xnn_create_clamp_nc_f16(
          channel_dim /* channels */, channel_dim /* input stride */, channel_dim /* output stride */,
          node->activation.output_min,
          node->activation.output_max,
          node->flags,
          &opdata->operator_object);
        break;
  #endif  // XNN_NO_F16_OPERATORS
      case xnn_compute_type_fp32:
        status = xnn_create_clamp_nc_f32(
          channel_dim /* channels */, channel_dim /* input stride */, channel_dim /* output stride */,
          node->activation.output_min,
          node->activation.output_max,
          node->flags,
          &opdata->operator_object);
        break;
  #ifndef XNN_NO_S8_OPERATORS
      case xnn_compute_type_qs8:
      {
        const float output_scale = values[output_id].quantization.scale;
        const int32_t output_zero_point = values[output_id].quantization.zero_point;
        const int8_t output_min =
          (int8_t) lrintf(fminf(fmaxf(node->activation.output_min / output_scale + (float) output_zero_point, -128.0f), 127.0f));
        const int8_t output_max =
          (int8_t) lrintf(fminf(fmaxf(node->activation.output_max / output_scale + (float) output_zero_point, -128.0f), 127.0f));
        status = xnn_create_clamp_nc_s8(
          channel_dim /* channels */, channel_dim /* input stride */, channel_dim /* output stride */,
          output_min,
          output_max,
          node->flags,
          &opdata->operator_object);
        break;
      }
  #endif  // !defined(XNN_NO_S8_OPERATORS)
  #ifndef XNN_NO_U8_OPERATORS
      case xnn_compute_type_qu8:
      {
        const float output_scale = values[output_id].quantization.scale;
        const int32_t output_zero_point = values[output_id].quantization.zero_point;
        const uint8_t output_min =
          (uint8_t) lrintf(fminf(fmaxf(node->activation.output_min / output_scale + (float) output_zero_point, 0.0f), 255.0f));
        const uint8_t output_max =
          (uint8_t) lrintf(fminf(fmaxf(node->activation.output_max / output_scale + (float) output_zero_point, 0.0f), 255.0f));
        status = xnn_create_clamp_nc_u8(
          channel_dim /* channels */, channel_dim /* input stride */, channel_dim /* output stride */,
          output_min,
          output_max,
          node->flags,
          &opdata->operator_object);
        break;
      }
  #endif  // !defined(XNN_NO_U8_OPERATORS)
      default:
        XNN_UNREACHABLE;
    }
    if (status == xnn_status_success) {
      opdata->batch_size = xnn_shape_multiply_non_channel_dims(&values[input_id].shape);
      opdata->inputs[0] = input_id;
      opdata->outputs[0] = output_id;
    }
    return status;
  }
  
  static enum xnn_status setup_clamp_operator(
    const struct xnn_operator_data* opdata,
    const struct xnn_blob* blobs,
    size_t num_blobs,
    pthreadpool_t threadpool)
  {
    const uint32_t input_id = opdata->inputs[0];
    assert(input_id != XNN_INVALID_VALUE_ID);
    assert(input_id < num_blobs);
  
    const uint32_t output_id = opdata->outputs[0];
    assert(output_id != XNN_INVALID_VALUE_ID);
    assert(output_id < num_blobs);
  
    const struct xnn_blob* input_blob = blobs + input_id;
    const void* input_data = input_blob->data;
    assert(input_data != NULL);
  
    const struct xnn_blob* output_blob = blobs + output_id;
    void* output_data = output_blob->data;
    assert(output_data != NULL);
  
    switch (opdata->operator_object->type) {
  #ifndef XNN_NO_F16_OPERATORS
      case xnn_operator_type_clamp_nc_f16:
        return xnn_setup_clamp_nc_f16(
          opdata->operator_object,
          opdata->batch_size,
          input_data,
          output_data,
          threadpool);
  #endif  // !defined(XNN_NO_F16_OPERATORS)
      case xnn_operator_type_clamp_nc_f32:
        return xnn_setup_clamp_nc_f32(
          opdata->operator_object,
          opdata->batch_size,
          input_data,
          output_data,
          threadpool);
  #ifndef XNN_NO_S8_OPERATORS
      case xnn_operator_type_clamp_nc_s8:
        return xnn_setup_clamp_nc_s8(
          opdata->operator_object,
          opdata->batch_size,
          input_data,
          output_data,
          threadpool);
  #endif  // !defined(XNN_NO_S8_OPERATORS)
  #ifndef XNN_NO_U8_OPERATORS
      case xnn_operator_type_clamp_nc_u8:
        return xnn_setup_clamp_nc_u8(
          opdata->operator_object,
          opdata->batch_size,
          input_data,
          output_data,
          threadpool);
        break;
  #endif  // !defined(XNN_NO_U8_OPERATORS)
      default:
        XNN_UNREACHABLE;
    }
  }
  
  enum xnn_status xnn_define_clamp(
    xnn_subgraph_t subgraph,
    float output_min,
    float output_max,
    uint32_t input_id,
    uint32_t output_id,
    uint32_t flags)
  {
    if ((xnn_params.init_flags & XNN_INIT_FLAG_XNNPACK) == 0) {
      xnn_log_error("failed to define %s operator: XNNPACK is not initialized",
        xnn_node_type_to_string(xnn_node_type_clamp));
      return xnn_status_uninitialized;
    }
  
    if (input_id >= subgraph->num_values) {
      xnn_log_error(
        "failed to define %s operator with input ID #%" PRIu32 ": invalid Value ID",
        xnn_node_type_to_string(xnn_node_type_clamp), input_id);
      return xnn_status_invalid_parameter;
    }
  
    const struct xnn_value* input_value = &subgraph->values[input_id];
    if (input_value->type != xnn_value_type_dense_tensor) {
      xnn_log_error(
        "failed to define %s operator with input ID #%" PRIu32 ": unsupported Value type %d (expected dense tensor)",
        xnn_node_type_to_string(xnn_node_type_clamp), input_id, input_value->type);
      return xnn_status_invalid_parameter;
    }
  
    switch (input_value->datatype) {
      case xnn_datatype_fp32:
  #ifndef XNN_NO_S8_OPERATORS
      case xnn_datatype_qint8:
  #endif  // !defined(XNN_NO_S8_OPERATORS)
  #ifndef XNN_NO_U8_OPERATORS
      case xnn_datatype_quint8:
  #endif  // !defined(XNN_NO_U8_OPERATORS)
        break;
      default:
        xnn_log_error(
          "failed to define %s operator with input ID #%" PRIu32 ": unsupported Value datatype %s (%d)",
          xnn_node_type_to_string(xnn_node_type_clamp), input_id,
          xnn_datatype_to_string(input_value->datatype), input_value->datatype);
        return xnn_status_invalid_parameter;
    }
  
    if (output_id >= subgraph->num_values) {
      xnn_log_error(
        "failed to define %s operator with output ID #%" PRIu32 ": invalid Value ID",
        xnn_node_type_to_string(xnn_node_type_clamp), output_id);
      return xnn_status_invalid_parameter;
    }
  
    const struct xnn_value* output_value = &subgraph->values[output_id];
    if (output_value->type != xnn_value_type_dense_tensor) {
      xnn_log_error(
        "failed to define %s operator with output ID #%" PRIu32 ": unsupported Value type %d (expected dense tensor)",
        xnn_node_type_to_string(xnn_node_type_clamp), output_id, output_value->type);
      return xnn_status_invalid_parameter;
    }
  
    enum xnn_compute_type compute_type = xnn_compute_type_invalid;
    switch (output_value->datatype) {
      case xnn_datatype_fp32:
        compute_type = xnn_compute_type_fp32;
        break;
  #ifndef XNN_NO_S8_OPERATORS
      case xnn_datatype_qint8:
        compute_type = xnn_compute_type_qs8;
        break;
  #endif  // !defined(XNN_NO_S8_OPERATORS)
  #ifndef XNN_NO_U8_OPERATORS
      case xnn_datatype_quint8:
        compute_type = xnn_compute_type_qu8;
        break;
  #endif  // !defined(XNN_NO_U8_OPERATORS)
      default:
        xnn_log_error(
          "failed to define %s operator with output ID #%" PRIu32 ": unsupported Value datatype %s (%d)",
          xnn_node_type_to_string(xnn_node_type_clamp), output_id,
          xnn_datatype_to_string(output_value->datatype), output_value->datatype);
        return xnn_status_invalid_parameter;
    }
    assert(compute_type != xnn_compute_type_invalid);
  
    if (input_value->datatype != output_value->datatype) {
      xnn_log_error(
        "failed to define %s operator with input ID #%" PRIu32 " and output ID #%" PRIu32
        ": mismatching datatypes across input (%s) and output (%s)",
        xnn_node_type_to_string(xnn_node_type_clamp), input_id, output_id,
        xnn_datatype_to_string(input_value->datatype),
        xnn_datatype_to_string(output_value->datatype));
      return xnn_status_invalid_parameter;
    }
  
  #if !defined(XNN_NO_U8_OPERATORS) || !defined(XNN_NO_S8_OPERATORS)
    if (compute_type == xnn_datatype_qint8 || compute_type == xnn_datatype_quint8) {
      if (input_value->quantization.zero_point != output_value->quantization.zero_point) {
        xnn_log_error(
          "failed to define %s operator with input ID #%" PRIu32 " and output ID #%" PRIu32
          ": mismatching zero point quantization parameter across input (%"PRId32") and output (%"PRId32")",
          xnn_node_type_to_string(xnn_node_type_clamp), input_id, output_id,
          input_value->quantization.zero_point, output_value->quantization.zero_point);
        return xnn_status_invalid_parameter;
      }
      if (input_value->quantization.scale != output_value->quantization.scale) {
        xnn_log_error(
          "failed to define %s operator with input ID #%" PRIu32 " and output ID #%" PRIu32
          ": mismatching zero point quantization parameter across input (%.7g) and output (%.7g)",
          xnn_node_type_to_string(xnn_node_type_clamp), input_id, output_id,
          input_value->quantization.scale, output_value->quantization.scale);
        return xnn_status_invalid_parameter;
      }
    }
  #endif  // !defined(XNN_NO_U8_OPERATORS) || !defined(XNN_NO_S8_OPERATORS)
  
    struct xnn_node* node = xnn_subgraph_new_node(subgraph);
    if (node == NULL) {
      return xnn_status_out_of_memory;
    }
  
    node->type = xnn_node_type_clamp;
    node->compute_type = compute_type;
    node->activation.output_min = output_min;
    node->activation.output_max = output_max;
    node->num_inputs = 1;
    node->inputs[0] = input_id;
    node->num_outputs = 1;
    node->outputs[0] = output_id;
    node->flags = flags;
  
    node->create = create_clamp_operator;
    node->setup = setup_clamp_operator;
  
    return xnn_status_success;
  }
  