nop meaning: definition, quotations

nop

noun

UK /nɒp/ · US /nɔp/

Computing, Engineering, Mathematics, Natural sciences, Physical sciences, Programming, Sciences A no-op; a CPU instruction that does nothing.

The MIPS instruction set is rich in nops, since any instruction with zero as a destination is guaranteed to do nothing.1999, Dominic Sweetman, See MIPS Run:
2004, Patterson et al, Computer Organization and Design: The Hardware/Software Interface Notice that in computing CPI or IPC, we do not count any nops executed as useful instructions.

verb

Computing, Engineering, Mathematics, Natural sciences, Physical sciences, Programming, Sciences To replace machine code with nop instructions when modifying software.

For example, if there is a CALL 3140 and we want to skip this call, we can NOP it out.1992, The Cyborg, The Cracking Manual:
Worse, some patching can result in codes which cannot be executed: for example nopping the load which provides the value for the denominator of a division can result in a division by zero.2012, Michael W. Berry, Kyle A. Gallivan, Efstratios Gallopoulos, High-Performance Scientific Computing: Algorithms and Applications:

Entry derived from the Wiktionary, under licence CC BY-SA 4.0 — list of authors.