Re: [PATCH 02/11] x86: code shrink in paranoid_exit

From: H. Peter Anvin
Date: Wed Feb 11 2015 - 16:02:39 EST


On 02/11/2015 12:36 PM, Andy Lutomirski wrote:
>
> This is sort of a reply to the wrong thread, but wouldn't it be nicer
> if we could pop a bunch of regs instead of using mov followed by add?
> (Yes, this could be a followup, but it could be easier to spot now by
> changing macros like RESTORE_XYZ.)
>

As far as I recall, it was an optimization for the Pentium 4 and
possibly K8. At this point, most CPUs have stack engines so push/pop
may be faster or at least the same speed. It would be nice to
microbenchmark.

-hpa


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