Remove BASOP_Util_Add_Mant32Exp() from ACcontextMapping_enc_fx.c

Basic info

It can be assumed, that the function BASOP_Util_Add_Mant32Exp() has been used as an intermediate step inside the file ACcontextMapping_enc_fx.c during the transistion from floating point to fixpoint. Though functional, it is eating up a lot of WMOPS. One solution could be to replace it by proper 64 Bit Fixpoint.

• Float reference:
  • Encoder (float):
  • Decoder (float):
• Fixed point:
  • Encoder (fixed):
  • Decoder (fixed):

Bug description

Ways to reproduce

Box folder: ...\Box_EXTERNAL_IVAS_BASOP_VERIFICATION\issues\issue-xxxx