Translate the following LEGv8 assembly into C, assuming that:

X19 = f, X20 = g, X21 = h, X22 = &a

SUB X9, X20, X21

CBZ X9, ELSE

LSL X9, X20, #3

ADD X9, X22, X9

LDUR X19, [X9, #0]

B END

ELSE: LDUR X19, [X22, #0]

END: SUB X21, X19, X20