q8_copy_int8_weight_and_add_offset Class — pytorch Architecture

Source Code

aten/src/ATen/native/quantized/cpu/XnnpackUtils.cpp lines 31–48

template <typename PT>
void q8_copy_int8_weight_and_add_offset(const at::Tensor& in, at::Tensor& out) {
  using T = typename PT::underlying;
  static constexpr auto offset = std::is_same_v<T, uint8_t> ? 128 : 0;
  TORCH_CHECK(
      in.scalar_type() == c10::kQInt8,
      "q8_copy_int8_weight_and_add_offset: Expected input weight data type ",
      toString(c10::kQInt8),
      " but got ",
      toString(in.scalar_type()))
  const int8_t* in_ptr =
      reinterpret_cast<const int8_t*>(in.data_ptr<c10::qint8>());
  T* out_ptr = reinterpret_cast<T*>(out.data_ptr<PT>());

  for (const auto i : c10::irange(in.numel())) {
    out_ptr[i] = static_cast<T>(static_cast<int32_t>(in_ptr[i]) + offset);
  }
}