From: Konstantin Ananyev <konstantin.ananyev@huawei.com>
To: "Morten Brørup" <mb@smartsharesystems.com>,
"Stephen Hemminger" <stephen@networkplumber.org>
Cc: "dev@dpdk.org" <dev@dpdk.org>,
Bruce Richardson <bruce.richardson@intel.com>
Subject: RE: [PATCH] eal/x86: optimize memcpy of small 64-byte blocks
Date: Wed, 5 Aug 2026 05:45:51 +0000 [thread overview]
Message-ID: <6f474724bc22441a8a4f516f3398ca76@huawei.com> (raw)
In-Reply-To: <98CBD80474FA8B44BF855DF32C47DC35F659B8@smartserver.smartshare.dk>
> > From: Stephen Hemminger [mailto:stephen@networkplumber.org]
> > Sent: Tuesday, 4 August 2026 17.52
> >
> > On Tue, 4 Aug 2026 14:33:04 +0000
> > Morten Brørup <mb@smartsharesystems.com> wrote:
> >
> > > + /* Common way for small copy size of 64-byte blocks. Unlikely, so
> > constant size only */
> > > + if (__rte_constant(n) && (n & 63) == 0 && n <=
> > RTE_MEMCPY_BLOCK_64_MAX) {
> > > + void *ret = dst;
> > > +
> >
> > Maybe just let compiler decide, it will generate vector instructions in
> > most cases.
> >
> > if (__rte_constant(n))
> > return mempcpy(dst, src, n);
>
> Maybe in most, but not in all:
> https://godbolt.org/z/KvdKqT5rY
With '-mavx' or '-mavx512f' it looks like it does for your sample code.
next prev parent reply other threads:[~2026-08-05 5:45 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-08-04 14:33 [PATCH] eal/x86: optimize memcpy of small 64-byte blocks Morten Brørup
2026-08-04 14:33 ` [RFC PATCH] pile stack and mempool driver (resend) Morten Brørup
2026-08-04 14:38 ` Morten Brørup
2026-08-04 15:52 ` [PATCH] eal/x86: optimize memcpy of small 64-byte blocks Stephen Hemminger
2026-08-04 16:25 ` Morten Brørup
2026-08-05 5:45 ` Konstantin Ananyev [this message]
2026-08-05 5:56 ` Morten Brørup
2026-08-05 6:50 ` Konstantin Ananyev
2026-08-05 8:36 ` Morten Brørup
2026-08-04 19:11 ` Morten Brørup
2026-08-04 20:42 ` Stephen Hemminger
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