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From: "hjl.tools at gmail dot com" <sourceware-bugzilla@sourceware.org>
To: glibc-bugs@sourceware.org
Subject: [Bug string/27130] New: "rep movsb" performance issue
Date: Wed, 30 Dec 2020 18:06:27 +0000
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https://sourceware.org/bugzilla/show_bug.cgi?id=3D27130

            Bug ID: 27130
           Summary: "rep movsb" performance issue
           Product: glibc
           Version: 2.33
            Status: NEW
          Severity: normal
          Priority: P2
         Component: string
          Assignee: unassigned at sourceware dot org
          Reporter: hjl.tools at gmail dot com
  Target Milestone: ---
            Target: x86-64

When copying with "rep movsb", if the distance between source and destinati=
on
is [1..63], performance can be very slow on some processors as shown in a t=
est
case at

https://gitlab.com/x86-benchmarks/microbenchmark/-/tree/memcpy/63b

--=20
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