Low bit support for ARM Cortex-M export

• Add aidge types (type not compressed & type compressed)
  • int4 (. . . . v v v v) & dual_int4 (v v v v v v v v)
  • int3 (. . . . . v v v) & dual_int3 (. v v v . v v v)
  • int2 & quad_int2
  • uint4 & dual_uint4
  • uint3 & dual_uint3
  • uint2 & quad_uint2
  • binary & octo_binary
• Each aidge type uses a std::int8_t or std::uint8_t (for aide tensor, tensor binding to numpy,...)
• Add operator WeightInterleaving that compact tensor data on the last dimension of the Tensor. It requires input tensor format NHWC because the implemented kernels in ARM Cortex-M are HWC.
• Python binding of Operator WeightInterleaving and ApplyWeightInterleaving recipe
• Adapt data_convertion to a generic function taking a data conversionmap as input and integrate it into nodeExport. Each nodeExport instanciation in the export operator registry can specify a different data conversion map (from aidge to export type).

Closes : aidge_export_arm_cortexm#22 (closed)

aidge_core/export_utils/data_conversion.py

@@ -19,6 +19,8 @@ datatype_converter_aide2c = {
 def aidge2c(datatype):
     """Convert a aidge datatype to C type
 
+    If the type is not convertible to a C type (e.g. int4), return None and raise a warning.
+
     :param datatype: Aidge datatype to convert
     :type datatype: :py:object:`aidge_core.DataType`
     :return: A string representing the C type
@@ -27,4 +29,6 @@ def aidge2c(datatype):
     if datatype in datatype_converter_aide2c:
         return datatype_converter_aide2c[datatype]
     else:
-        raise ValueError(f"Unsupported {datatype} aidge datatype")
+        # raise ValueError(f"Unsupported {datatype} aidge datatype")
+        aidge_core.Log.warn(f"Unsupported conversion of {datatype} (aidge datatype) to a C type.")
+        return None