def _get_final_replacement(self, replacement_map, instr):
        '''Find the final replacement instruction for a given initial
        instruction by chasing instructions in a map from instructions
        to replacement instructions.
        '''
        replacement = replacement_map[instr]
        while replacement in replacement_map:
            replacement = replacement_map[replacement]
        return replacement
Find the final replacement instruction for a given initial
        instruction by chasing instructions in a map from instructions
        to replacement instructions.
        
numba/np/ufunc/array_exprs.py