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A comment on XOR'ing a register with itself is the idiom for zeroing it out. Why not sub?. Parent comment

Re:XOR'ing a register with itself is the idiom for zeroing i... by virexene on Wednesday April 22, 2026 @03:57AM (#47860489)
The operation is slightly more complex yes, but has there ever been an x86 CPU where SUB or XOR takes more than a single CPU cycle?
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Re:XOR'ing a register with itself is the idiom for zeroing i... by praptak on Wednesday April 22, 2026 @04:01AM (#47860524)
I wonder if you could measure the difference in power consumption.

I mean, not for zeroing because we know from the TFA that it's special-cased anyway. But maybe if you test on different registers?

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