BFI : Bit Field Insert

SPA 5.0:
        {@{!}Pg}   BFI   Rd{.CC},Ra,Sb,Sc   {&req_6}   {?sched}   ;   

 .CC:       Write condition codes

BFI allows the following sources Sb,Sc:
    Sb(register),                         Sc(register)
    Sb(constant with immediate address),  Sc(register)
    Sb(#Imm20),                           Sc(register)
    Sb(register),                         Sc(constant with immediate address)

Align and insert a right-aligned bit field from Ra into Sc.

Sb contains:

   bits[07:00]: start position of inserted bit field
   bits[15:08]: size of inserted bit field

If the position is greater or equal to 32, Sc is copied to destination unchanged.
If the bit field insert size is 0, Sc is copied to destination unchanged
If the bit field insert size is greater than 32, then BFI behaves as if the width was 32.

BFI R0,R1,R2,R3;