    /*
     * Return the length of an array.
     */
    mov     r1, rINST, lsr #12          @ r1<- B
    ubfx    r2, rINST, #8, #4           @ r2<- A
    GET_VREG r0, r1                     @ r0<- vB (object ref)
    cmp     r0, #0                      @ is object null?
    beq     common_errNullObject        @ yup, fail
    FETCH_ADVANCE_INST 1                @ advance rPC, load rINST
    ldr     r3, [r0, #MIRROR_ARRAY_LENGTH_OFFSET]    @ r3<- array length
    GET_INST_OPCODE ip                  @ extract opcode from rINST
    SET_VREG r3, r2                     @ vB<- length
    GOTO_OPCODE ip                      @ jump to next instruction
