RE: [PATCH 04/18] csum_and_copy_..._user(): pass 0xffffffff instead of 0 as initial sum

[David Laight]

From: Al Viro
> Sent: 23 July 2020 16:21
...
> The point is, your "~4.5 cycles per vector" is pretty much noise and the
> difference between the 3-argument and 4-argument variants could easily be
> in the same range.  It might be a valid microoptimization, it might be not.
> 3-argument variant is simpler and IMO in absence of strong data we ought
> to go with that.

There is definitely more to be gained by rewriting the x86-86 asm.

	David

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