assembly - What is faster: JMP or string of NOPs? -

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i'm implementing binary translation , have deal sequences of nops (0x90) length 16 opcodes. better performance place jmp (to end) @ start of such sequences?

the intel architecture software developer's guide, volume 2b (instructions n-z) contains following table (pg 4-12) nop:

table 4-9. recommended multi-byte sequence of nop instruction

 length    assembly                                   byte sequence ================================================================================= 2 bytes   66 nop                                     66 90h 3 bytes   nop dword ptr [eax]                        0f 1f 00h 4 bytes   nop dword ptr [eax + 00h]                  0f 1f 40 00h 5 bytes   nop dword ptr [eax + eax*1 + 00h]          0f 1f 44 00 00h 6 bytes   66 nop dword ptr [eax + eax*1 + 00h]       66 0f 1f 44 00 00h 7 bytes   nop dword ptr [eax + 00000000h]            0f 1f 80 00 00 00 00h 8 bytes   nop dword ptr [eax + eax*1 + 00000000h]    0f 1f 84 00 00 00 00 00h 9 bytes   66 nop dword ptr [eax + eax*1 + 00000000h] 66 0f 1f 84 00 00 00 00 00h

this allows construct "padding nop" of sizes. 2 of those, can bridge 16 bytes, although second suggestion check optimization guides (for cpu you're targeting) whether jmp faster 2 such nops.


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