10.67 NOP

No Operation.


is an optional condition code.


NOP does nothing. If NOP is not implemented as a specific instruction on your target architecture, the assembler treats it as a pseudo-instruction and generates an alternative instruction that does nothing, such as MOV r0, r0 (ARM) or MOV r8, r8 (Thumb).
NOP is not necessarily a time-consuming NOP. The processor might remove it from the pipeline before it reaches the execution stage.
You can use NOP for padding, for example to place the following instruction on a 64-bit boundary in ARM, or a 32-bit boundary in Thumb.


This ARM instruction is available in ARMv6K and above.
This 32-bit Thumb instruction is available in ARMv6T2 and above.
This 16-bit Thumb instruction is available in ARMv6T2 and above.
NOP is available on all other ARM and Thumb architectures as a pseudo-instruction.
Related reference
10.8 Condition code suffixes
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