2.6.9.2.2 Operation
Use the CBZ or CBNZ instructions to avoid changing the condition code flags and to reduce the number of instructions.
CBZ Rn, label does not change condition flags but is otherwise equivalent to:
CMP Rn, #0
BEQ label
CBNZ Rn, label does not change condition flags but is otherwise equivalent to:
CMP Rn, #0
BNE label