On Mon, Jun 15, 2026 at 09:48:00PM -0700, Richard Henderson wrote: > On 6/15/26 21:23, Michael S. Tsirkin wrote: > > B. Also on x86, I do not see why we should not use memcpy for large > > accesses if we can. Better perf. > > We have an example where memcpy writes to the same location 3 times. > This is not appropriate for any host. > > > r~
Ah, checked libc and sure enough, it does it. E.g. it uses 2 overlapping SSE stores to do a 17 byte write. Not sure how we get 3 but whatevs. But just to clarify, I am talking about DMA accesses, that are not initiated by the VCPU. I am not so sure we care about multiple stores in this instance? Do we? We do care about speed, for sure. -- MST
