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

 import numpy as np
 import aidge_core
 
+from typing import Dict
 
-datatype_converter_aide2c = {
+datatype_converter_aidge2c = {
     aidge_core.dtype.float64 : "double",
     aidge_core.dtype.float32 : "float",
     aidge_core.dtype.float16 : "half_float::half",
@@ -19,12 +20,31 @@ 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
     :rtype: string
     """
-    if datatype in datatype_converter_aide2c:
-        return datatype_converter_aide2c[datatype]
+    if datatype in datatype_converter_aidge2c:
+        return datatype_converter_aidge2c[datatype]
     else:
         raise ValueError(f"Unsupported {datatype} aidge datatype")
+
+def aidge2export_type(datatype: aidge_core.dtype, conversion_map: Dict[aidge_core.dtype, str] = datatype_converter_aidge2c) -> str:
+    """Convert a aidge datatype to the export type specified by the map passed in argument
+
+    If the aidge type is not convertible, that is to say, is not specified in the map, a value Error is raised.
+
+    :param datatype: Aidge datatype to convert
+    :type datatype: :py:object:`aidge_core.DataType`
+    :param conversion_map: Map that specify the conversion
+    :type conversion_map: Dict[:py:object:`aidge_core.DataType`, str]
+    :return: A string representing the export type
+    :rtype: string
+    """
+    if datatype in conversion_map:
+        return conversion_map[datatype]
+    else:
+        raise ValueError(f"Unsupported type conversion {datatype} aidge datatype for export")