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Groups > comp.lang.c++ > #67667

Re: Performance of unaligned memory-accesses

From David Brown <david.brown@hesbynett.no>
Newsgroups comp.lang.c++
Subject Re: Performance of unaligned memory-accesses
Date 2019-08-15 10:15 +0200
Organization A noiseless patient Spider
Message-ID <qj34ac$4m0$1@dont-email.me> (permalink)
References (17 earlier) <qiufut$cde$1@news.albasani.net> <86mugb7lvg.fsf@mailhub.linuxsc.com> <qj1l7a$b1i$1@news.albasani.net> <d6d186f1-45fa-4a1c-9d5f-1154f9b9ac5d@googlegroups.com> <lnlfvv5rp9.fsf@kst-u.example.com>

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On 15/08/2019 00:04, Keith Thompson wrote:
> Öö Tiib <ootiib@hot.ee> writes:
>> On Wednesday, 14 August 2019 21:51:32 UTC+3, Bonita Montero  wrote:
>>>>> As I said that's not undefined behaviour because the compiler would
>>>>> be unable to generate the code as expected but because the CPU might
>>>>> fail / trap an unaligned access at runtime and the OS might emulate
>>>>> tzhe unaligned access or not.  So it depends on the platform you
>>>>> target.
>>>
>>>> If a given operation has undefined behavior, it doesn't stop
>>>> having undefined behavior just because it happens to do what
>>>> you want it to.
>>>
>>> In theory, but in practice it has an expectable behaviour depending
>>> on the platform.
>>
>> So it may change because of change of compiler, its version, compiling
>> options, device that it is ran on, settings of operating system or
>> other (possibly unrelated) code in same code-base.
>> Program that happens to do something in narrow conditions but not in
>> others is unreliable and unreliability is the most disliked property
>> of software.
> 
> It's important to remember what "undefined behavior" means.  It's not
> "this program will blow up".  It is simply
> 
>     behavior for which this document imposes no requirements
> 
> where "this document" is the C++ standard.  If something other than
> the standard imposes requirements, it's still undefined behavior.
> 

True.

But in this case, nothing else imposes requirements or definitions
either, leaving the behaviour undefined.

Neither Bonita nor anyone else has given any references, pointers to
documentation or manuals, or other indications that their C or C++
compiler supports unaligned accesses via normal pointers.

So this /is/ undefined behaviour - nothing has defined the behaviour in
question.  But that does not imply that there is unexpected or
undesirable behaviour - it seems that in all testing that has been done,
compilers treated the unaligned accesses as though they /were/ defined,
in the expected way, and that is what Bonita desires.

> If you want to talk about unexpected or undesirable behavior,
> call it that.  That's not what "undefined behavior" means.
> 

That distinction is important.  However, the behaviour here is
undefined, but it is not unexpected and not (to Bonita) undesirable.


Let me try to summarise what we know about unaligned accesses, and I
think you will see what I mean.

At the hardware level, we know:

1. Many cpus support unaligned accesses (though perhaps with
limitations, such as slower access or lacking features like locks or
atomic guarantees).  Examples include x86 and Arm-64.

2. Many cpus trap on unaligned accesses.  Examples include SPARC, Arm-32.

3. Some cpus have silent corruption on unaligned accesses, such as the
MSP430.

4. For some cpu families, there are members that support unaligned
accesses, and members that trap, despite having broadly compatible
binary code.  That includes the 68K family.


At the OS level, we know:

1. Some OS's have trap handlers that emulate the unaligned access for
processors that don't support it in hardware.  That includes at least
some versions of Solaris for SPARC, and some (but not all) 32-bit ARM
Linux systems.

2. Other OS's don't have such handlers.


At the language standards level, we know:

1. The C standards clearly state that creating unaligned pointers is
undefined behaviour in most cases.  (It may be possible, using something
like memcpy.)  Dereferencing unaligned pointers is explicitly undefined
behaviour.

2. The C++ standards are not as clear to me (due to lack of
familiarity), but I believe using unaligned pointers is also undefined
in C++.

3. In C and C++, the actual alignments are implementation dependent, and
are not required to be the same as the sizes of the types or the
"natural" alignment preferred by the hardware.

4. The standards rarely say something is "not allowed", but explicitly
stating that something is "undefined behaviour" is usually interpreted
as a strong suggestion to avoid the behaviour in portable code, and to
avoid it in non-portable code unless the compiler explicitly defines the
behaviour.  For safe and reliable coding standards, this is often an
rule rather than a suggestion.


At the compiler level, we know:

1. You can always access unaligned data by char, or by using memcpy.
Many compilers will turn common patterns into optimal instructions for
the target, while the source code remains safe, portable and fully
defined on all toolchains and targets.

2. Many compilers support extensions that can be used to safely and
reliably access unaligned data in convenient ways, such as "packed"
structs or MSVC's "__unaligned" keyword.  These methods are documented,
and will work correctly even on targets that don't support unaligned
access in hardware.

3. Compilers try to minimise surprises, unexpected code generation, and
behaviour changes for code that "worked with an older version".

4. Compilers try to maximise efficiency of correct code.  This is
sometimes in conflict with point 3.

5. Compilers optimise on the assumption that certain types of undefined
behaviour do not occur (or at least, the programmer doesn't care what
happens if it does occur).  This applies to /all/ compilers.  But some
compilers are more aggressive about this than others.

6. No tests have yet shown a compiler optimising on the assumption that
pointers are aligned (for targets that support unaligned accesses).
That may be luck, limitations of tests, or limitations of optimisations.
 It may also be intentional but undocumented behaviour for the compiler.

7. No references have been found for any compiler that explicitly
documents supporting unaligned accesses (other than via specific
extensions).

8. Compilers are often poor at issuing warnings or errors about
undefined behaviour or potentially undefined behaviour, such as making
or using unaligned pointers.

9. Future directions of compiler technology, including link-time
optimisations and pointer provenance tracking, make it a serious risk
that compilers /will/ optimise code on the assumption that pointers are
valid (including being aligned).  Hopefully, this will also improve
their ability to warn about potential problems.


So we know that general unaligned accesses usually appear to work as
expected and as desired (by those that use them).  But we know that this
is not documented or defined anywhere, not guaranteed, and certainly not
portable to all types of processor.  We know it is often considered bad,
or at least risky, programming practice from general rule of "don't rely
on undefined behaviour".  We know that despite working now, it might
fail in the future.  We know that some programmers are quite happy with
"it worked when I tried it" coding, without concern for guarantees or
documentation of behaviour.


To me, using unaligned pointers is therefore a fine example of undefined
behaviour, and Bonita's blasé attitude is an example of what is often
wrong in the programming world.

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Thread

Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-07 07:13 +0200
  Re: Performance of unaligned memory-accesses "Chris M. Thomasson" <invalid_chris_thomasson_invalid@invalid.com> - 2019-08-06 23:20 -0700
    Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-07 08:57 +0200
      Re: Performance of unaligned memory-accesses "Chris M. Thomasson" <invalid_chris_thomasson_invalid@invalid.com> - 2019-08-07 00:22 -0700
        Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-07 09:26 +0200
          Re: Performance of unaligned memory-accesses "Chris M. Thomasson" <invalid_chris_thomasson_invalid@invalid.com> - 2019-08-07 00:33 -0700
            Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-07 09:52 +0200
              Re: Performance of unaligned memory-accesses "Chris M. Thomasson" <invalid_chris_thomasson_invalid@invalid.com> - 2019-08-07 13:37 -0700
                Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-08 08:06 +0200
                Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-08 08:14 +0200
                Re: Performance of unaligned memory-accesses "Chris M. Thomasson " <ahh_f_it@crap.nothing> - 2019-08-08 00:00 -0700
                Re: Performance of unaligned memory-accesses "Chris M. Thomasson " <ahh_f_it@crap.nothing> - 2019-08-07 23:59 -0700
                Re: Performance of unaligned memory-accesses "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2019-08-17 22:13 -0700
          Re: Performance of unaligned memory-accesses "Chris M. Thomasson" <invalid_chris_thomasson_invalid@invalid.com> - 2019-08-07 00:35 -0700
          Re: Performance of unaligned memory-accesses scott@slp53.sl.home (Scott Lurndal) - 2019-08-07 14:47 +0000
            Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-07 16:55 +0200
              Re: Performance of unaligned memory-accesses scott@slp53.sl.home (Scott Lurndal) - 2019-08-07 15:11 +0000
                Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-07 17:41 +0200
                Re: Performance of unaligned memory-accesses scott@slp53.sl.home (Scott Lurndal) - 2019-08-07 15:58 +0000
      Re: Performance of unaligned memory-accesses "Chris M. Thomasson" <invalid_chris_thomasson_invalid@invalid.com> - 2019-08-07 00:24 -0700
        Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-07 10:07 +0200
          Re: Performance of unaligned memory-accesses "Chris M. Thomasson" <invalid_chris_thomasson_invalid@invalid.com> - 2019-08-07 20:55 -0700
            Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-08 08:03 +0200
              Re: Performance of unaligned memory-accesses "Chris M. Thomasson" <invalid_chris_thomasson_invalid@invalid.com> - 2019-08-07 23:54 -0700
    Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-07 08:57 +0200
      Re: Performance of unaligned memory-accesses "Chris M. Thomasson" <invalid_chris_thomasson_invalid@invalid.com> - 2019-08-07 22:42 -0700
    Re: Performance of unaligned memory-accesses scott@slp53.sl.home (Scott Lurndal) - 2019-08-07 14:46 +0000
      Re: Performance of unaligned memory-accesses "Chris M. Thomasson" <invalid_chris_thomasson_invalid@invalid.com> - 2019-08-07 14:09 -0700
  Re: Performance of unaligned memory-accesses Paavo Helde <myfirstname@osa.pri.ee> - 2019-08-07 11:00 +0300
    Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-07 10:03 +0200
      Re: Performance of unaligned memory-accesses Paavo Helde <myfirstname@osa.pri.ee> - 2019-08-07 11:46 +0300
    Re: Performance of unaligned memory-accesses David Brown <david.brown@hesbynett.no> - 2019-08-07 11:19 +0200
      Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-07 13:13 +0200
        Re: Performance of unaligned memory-accesses David Brown <david.brown@hesbynett.no> - 2019-08-07 13:29 +0200
          Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-07 14:02 +0200
            Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-07 14:08 +0200
              Re: Performance of unaligned memory-accesses David Brown <david.brown@hesbynett.no> - 2019-08-07 15:57 +0200
  Re: Performance of unaligned memory-accesses Jorgen Grahn <grahn+nntp@snipabacken.se> - 2019-08-07 12:37 +0000
    Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-07 14:47 +0200
      Re: Performance of unaligned memory-accesses David Brown <david.brown@hesbynett.no> - 2019-08-07 16:18 +0200
        Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-07 16:53 +0200
          Re: Performance of unaligned memory-accesses David Brown <david.brown@hesbynett.no> - 2019-08-07 17:30 +0200
            Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-07 17:39 +0200
              Re: Performance of unaligned memory-accesses David Brown <david.brown@hesbynett.no> - 2019-08-07 18:12 +0200
                Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-07 18:33 +0200
                Re: Performance of unaligned memory-accesses David Brown <david.brown@hesbynett.no> - 2019-08-07 21:32 +0200
                Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-07 22:01 +0200
                Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-07 22:48 +0200
                Re: Performance of unaligned memory-accesses Chris Vine <chris@cvine--nospam--.freeserve.co.uk> - 2019-08-07 23:02 +0100
                Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-08 07:43 +0200
                Re: Performance of unaligned memory-accesses "Chris M. Thomasson" <invalid_chris_thomasson_invalid@invalid.com> - 2019-08-07 22:54 -0700
                Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-08 08:04 +0200
                Re: Performance of unaligned memory-accesses "Chris M. Thomasson" <invalid_chris_thomasson_invalid@invalid.com> - 2019-08-08 00:16 -0700
                Re: Performance of unaligned memory-accesses David Brown <david.brown@hesbynett.no> - 2019-08-08 09:58 +0200
                Re: Performance of unaligned memory-accesses "Chris M. Thomasson" <invalid_chris_thomasson_invalid@invalid.com> - 2019-08-08 01:20 -0700
                Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-08 16:47 +0200
                Re: Performance of unaligned memory-accesses Chris Vine <chris@cvine--nospam--.freeserve.co.uk> - 2019-08-08 10:29 +0100
                Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-08 16:50 +0200
                Re: Performance of unaligned memory-accesses David Brown <david.brown@hesbynett.no> - 2019-08-08 17:05 +0200
                Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-08 17:33 +0200
                Re: Performance of unaligned memory-accesses David Brown <david.brown@hesbynett.no> - 2019-08-08 09:56 +0200
                Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-08 16:51 +0200
                Re: Performance of unaligned memory-accesses David Brown <david.brown@hesbynett.no> - 2019-08-08 17:10 +0200
                Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-08 17:35 +0200
                Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-08 17:38 +0200
                Re: Performance of unaligned memory-accesses David Brown <david.brown@hesbynett.no> - 2019-08-08 21:45 +0200
                Re: Performance of unaligned memory-accesses scott@slp53.sl.home (Scott Lurndal) - 2019-08-08 20:00 +0000
                Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-09 06:52 +0200
                Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-09 07:59 +0200
                Re: Performance of unaligned memory-accesses David Brown <david.brown@hesbynett.no> - 2019-08-09 09:19 +0200
                Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-09 09:32 +0200
                Re: Performance of unaligned memory-accesses David Brown <david.brown@hesbynett.no> - 2019-08-09 10:14 +0200
                Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-09 10:21 +0200
                Re: Performance of unaligned memory-accesses David Brown <david.brown@hesbynett.no> - 2019-08-09 13:01 +0200
                Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-09 13:09 +0200
                Re: Performance of unaligned memory-accesses David Brown <david.brown@hesbynett.no> - 2019-08-09 15:38 +0200
                Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-09 15:45 +0200
                Re: Performance of unaligned memory-accesses Robert Wessel <robertwessel2@yahoo.com> - 2019-08-09 09:37 -0500
                Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-09 16:59 +0200
                Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-09 17:04 +0200
                Re: Performance of unaligned memory-accesses Bart <bc@freeuk.com> - 2019-08-09 16:43 +0100
                Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-09 19:18 +0200
                Re: Performance of unaligned memory-accesses Bart <bc@freeuk.com> - 2019-08-09 23:28 +0100
                Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-10 08:55 +0200
                Re: Performance of unaligned memory-accesses David Brown <david.brown@hesbynett.no> - 2019-08-10 17:21 +0200
                Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-10 17:25 +0200
                Re: Performance of unaligned memory-accesses David Brown <david.brown@hesbynett.no> - 2019-08-10 23:32 +0200
                Re: Performance of unaligned memory-accesses Ian Collins <ian-news@hotmail.com> - 2019-08-11 10:59 +1200
                Re: Performance of unaligned memory-accesses David Brown <david.brown@hesbynett.no> - 2019-08-11 02:24 +0200
                Re: Performance of unaligned memory-accesses Keith Thompson <kst-u@mib.org> - 2019-08-10 17:53 -0700
                Re: Performance of unaligned memory-accesses David Brown <david.brown@hesbynett.no> - 2019-08-11 17:26 +0200
                Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-11 19:18 +0200
                Re: Performance of unaligned memory-accesses David Brown <david.brown@hesbynett.no> - 2019-08-11 23:00 +0200
                Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-11 23:44 +0200
                Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-11 23:46 +0200
                Re: Performance of unaligned memory-accesses David Brown <david.brown@hesbynett.no> - 2019-08-12 01:02 +0200
                Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-12 09:15 +0200
                Re: Performance of unaligned memory-accesses "Chris M. Thomasson" <invalid_chris_thomasson_invalid@example.com> - 2019-08-11 16:37 -0700
                Re: Performance of unaligned memory-accesses "Chris M. Thomasson" <invalid_chris_thomasson_invalid@example.com> - 2019-08-11 16:42 -0700
                Re: Performance of unaligned memory-accesses "Chris M. Thomasson" <invalid_chris_thomasson_invalid@example.com> - 2019-08-11 22:05 -0700
                Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-11 07:25 +0200
                Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-11 07:24 +0200
                Re: Performance of unaligned memory-accesses Keith Thompson <kst-u@mib.org> - 2019-08-10 17:22 -0700
                Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-11 07:23 +0200
                Re: Performance of unaligned memory-accesses David Brown <david.brown@hesbynett.no> - 2019-08-10 17:10 +0200
                Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-10 17:21 +0200
                Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-10 17:31 +0200
                Re: Performance of unaligned memory-accesses David Brown <david.brown@hesbynett.no> - 2019-08-10 23:47 +0200
                Re: Performance of unaligned memory-accesses Keith Thompson <kst-u@mib.org> - 2019-08-10 17:40 -0700
                Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-11 07:27 +0200
                Re: Performance of unaligned memory-accesses David Brown <david.brown@hesbynett.no> - 2019-08-10 23:46 +0200
                Re: Performance of unaligned memory-accesses Bart <bc@freeuk.com> - 2019-08-10 23:22 +0100
                Re: Performance of unaligned memory-accesses James Kuyper <jameskuyper@alumni.caltech.edu> - 2019-08-10 16:11 -0700
                Re: Performance of unaligned memory-accesses Keith Thompson <kst-u@mib.org> - 2019-08-10 17:32 -0700
                Re: Performance of unaligned memory-accesses David Brown <david.brown@hesbynett.no> - 2019-08-11 15:41 +0200
                Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-11 15:55 +0200
                Re: Performance of unaligned memory-accesses David Brown <david.brown@hesbynett.no> - 2019-08-11 18:06 +0200
                Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-11 18:15 +0200
                Re: Performance of unaligned memory-accesses David Brown <david.brown@hesbynett.no> - 2019-08-11 18:59 +0200
                Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-11 19:03 +0200
                Re: Performance of unaligned memory-accesses David Brown <david.brown@hesbynett.no> - 2019-08-11 23:48 +0200
                Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-12 00:15 +0200
                Re: Performance of unaligned memory-accesses David Brown <david.brown@hesbynett.no> - 2019-08-12 01:06 +0200
                Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-12 09:13 +0200
                Re: Performance of unaligned memory-accesses David Brown <david.brown@hesbynett.no> - 2019-08-12 13:32 +0200
                Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-12 13:40 +0200
                Re: Performance of unaligned memory-accesses Melzzzzz <Melzzzzz@zzzzz.com> - 2019-08-12 11:44 +0000
                Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-12 14:30 +0200
                Re: Performance of unaligned memory-accesses Melzzzzz <Melzzzzz@zzzzz.com> - 2019-08-12 13:09 +0000
                Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-12 15:14 +0200
                Re: Performance of unaligned memory-accesses Melzzzzz <Melzzzzz@zzzzz.com> - 2019-08-12 19:13 +0000
                Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-12 21:15 +0200
                Re: Performance of unaligned memory-accesses Melzzzzz <Melzzzzz@zzzzz.com> - 2019-08-12 19:25 +0000
                Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-13 02:28 +0200
                Re: Performance of unaligned memory-accesses Melzzzzz <Melzzzzz@zzzzz.com> - 2019-08-13 01:08 +0000
                Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-13 16:03 +0200
                Re: Performance of unaligned memory-accesses Tim Rentsch <tr.17687@z991.linuxsc.com> - 2019-08-14 09:27 -0700
                Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-14 20:51 +0200
                Re: Performance of unaligned memory-accesses Öö Tiib <ootiib@hot.ee> - 2019-08-14 13:14 -0700
                Re: Performance of unaligned memory-accesses Keith Thompson <kst-u@mib.org> - 2019-08-14 15:04 -0700
                Re: Performance of unaligned memory-accesses Öö Tiib <ootiib@hot.ee> - 2019-08-14 15:47 -0700
                Re: Performance of unaligned memory-accesses David Brown <david.brown@hesbynett.no> - 2019-08-15 10:15 +0200
                Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-15 07:11 +0200
                Re: Performance of unaligned memory-accesses Öö Tiib <ootiib@hot.ee> - 2019-08-14 23:37 -0700
                Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-15 09:25 +0200
                Re: Performance of unaligned memory-accesses Öö Tiib <ootiib@hot.ee> - 2019-08-15 03:41 -0700
                Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-15 14:25 +0200
                Re: Performance of unaligned memory-accesses David Brown <david.brown@hesbynett.no> - 2019-08-15 16:06 +0200
                Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-15 16:21 +0200
                Re: Performance of unaligned memory-accesses Tim Rentsch <tr.17687@z991.linuxsc.com> - 2019-08-15 16:56 -0700
                Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-16 06:44 +0200
                Re: Performance of unaligned memory-accesses James Kuyper <jameskuyper@alumni.caltech.edu> - 2019-08-14 16:53 -0700
                Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-11 18:40 +0200
                Re: Performance of unaligned memory-accesses Ralf Goertz <me@myprovider.invalid> - 2019-08-13 08:53 +0200
                Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-13 09:18 +0200
                Re: Performance of unaligned memory-accesses Bart <bc@freeuk.com> - 2019-08-11 19:00 +0100
                Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-11 21:06 +0200
                Re: Performance of unaligned memory-accesses Keith Thompson <kst-u@mib.org> - 2019-08-11 13:07 -0700
                Re: Performance of unaligned memory-accesses Bart <bc@freeuk.com> - 2019-08-11 23:58 +0100
                Re: Performance of unaligned memory-accesses Keith Thompson <kst-u@mib.org> - 2019-08-11 17:07 -0700
                Re: Performance of unaligned memory-accesses Chris Vine <chris@cvine--nospam--.freeserve.co.uk> - 2019-08-12 10:14 +0100
                Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-12 11:30 +0200
                Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-12 13:03 +0200
                Re: Performance of unaligned memory-accesses Chris Vine <chris@cvine--nospam--.freeserve.co.uk> - 2019-08-12 13:06 +0100
                Re: Performance of unaligned memory-accesses Bart <bc@freeuk.com> - 2019-08-12 10:34 +0100
                Re: Performance of unaligned memory-accesses Keith Thompson <kst-u@mib.org> - 2019-08-12 08:49 -0700
                Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-12 18:10 +0200
                Re: Performance of unaligned memory-accesses Öö Tiib <ootiib@hot.ee> - 2019-08-12 09:22 -0700
                Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-12 18:24 +0200
                Re: Performance of unaligned memory-accesses James Kuyper <jameskuyper@alumni.caltech.edu> - 2019-08-12 16:38 -0700
                Re: Performance of unaligned memory-accesses Keith Thompson <kst-u@mib.org> - 2019-08-12 09:33 -0700
                Re: Performance of unaligned memory-accesses Keith Thompson <kst-u@mib.org> - 2019-08-11 13:11 -0700
                Re: Performance of unaligned memory-accesses David Brown <david.brown@hesbynett.no> - 2019-08-11 23:59 +0200
                Re: Performance of unaligned memory-accesses James Kuyper <jameskuyper@alumni.caltech.edu> - 2019-08-10 19:31 -0400
                Re: Performance of unaligned memory-accesses David Brown <david.brown@hesbynett.no> - 2019-08-11 15:52 +0200
                Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-11 07:28 +0200
                Re: Performance of unaligned memory-accesses James Kuyper <jameskuyper@alumni.caltech.edu> - 2019-08-10 16:37 -0700
                Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-09 21:35 +0200
                Re: Performance of unaligned memory-accesses David Brown <david.brown@hesbynett.no> - 2019-08-08 21:43 +0200
                Re: Performance of unaligned memory-accesses Jorgen Grahn <grahn+nntp@snipabacken.se> - 2019-08-08 12:51 +0000
                Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-08 16:55 +0200
                Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-08 16:57 +0200
            Re: Performance of unaligned memory-accesses scott@slp53.sl.home (Scott Lurndal) - 2019-08-07 16:07 +0000
              Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-07 18:38 +0200
                Re: Performance of unaligned memory-accesses scott@slp53.sl.home (Scott Lurndal) - 2019-08-07 17:34 +0000
                Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-07 20:07 +0200
                Re: Performance of unaligned memory-accesses scott@slp53.sl.home (Scott Lurndal) - 2019-08-07 20:16 +0000
                Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-07 22:42 +0200
                Re: Performance of unaligned memory-accesses scott@slp53.sl.home (Scott Lurndal) - 2019-08-07 21:19 +0000
                Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-07 23:40 +0200
              Re: Performance of unaligned memory-accesses Jorgen Grahn <grahn+nntp@snipabacken.se> - 2019-08-07 19:58 +0000
                Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-07 22:08 +0200
                Re: Performance of unaligned memory-accesses David Brown <david.brown@hesbynett.no> - 2019-08-07 22:13 +0200
                Re: Performance of unaligned memory-accesses Jorgen Grahn <grahn+nntp@snipabacken.se> - 2019-08-21 20:26 +0000
            Re: Performance of unaligned memory-accesses Christopher Collins <ccollins476ad@gmail.com> - 2019-08-07 12:50 -0700
              Re: Performance of unaligned memory-accesses David Brown <david.brown@hesbynett.no> - 2019-08-07 22:18 +0200
                Re: Performance of unaligned memory-accesses Bart <bc@freeuk.com> - 2019-08-07 22:52 +0100
                Re: Performance of unaligned memory-accesses Keith Thompson <kst-u@mib.org> - 2019-08-07 17:52 -0700
                Re: Performance of unaligned memory-accesses David Brown <david.brown@hesbynett.no> - 2019-08-08 10:39 +0200
                Re: Performance of unaligned memory-accesses Bart <bc@freeuk.com> - 2019-08-08 13:48 +0100
                Re: Performance of unaligned memory-accesses David Brown <david.brown@hesbynett.no> - 2019-08-08 15:53 +0200
                Re: Performance of unaligned memory-accesses Keith Thompson <kst-u@mib.org> - 2019-08-07 17:27 -0700
                Re: Performance of unaligned memory-accesses David Brown <david.brown@hesbynett.no> - 2019-08-08 10:43 +0200
                Re: Performance of unaligned memory-accesses Keith Thompson <kst-u@mib.org> - 2019-08-08 13:33 -0700
                Re: Performance of unaligned memory-accesses David Brown <david.brown@hesbynett.no> - 2019-08-08 23:34 +0200
                Re: Performance of unaligned memory-accesses Christopher Collins <ccollins476ad@gmail.com> - 2019-08-07 17:28 -0700
                Re: Performance of unaligned memory-accesses Bonita Montero <Bonita.Montero@gmail.com> - 2019-08-08 09:30 +0200
            Re: Performance of unaligned memory-accesses "Chris M. Thomasson" <invalid_chris_thomasson_invalid@invalid.com> - 2019-08-07 14:20 -0700
            Re: Performance of unaligned memory-accesses Keith Thompson <kst-u@mib.org> - 2019-08-07 17:27 -0700
              Re: Performance of unaligned memory-accesses David Brown <david.brown@hesbynett.no> - 2019-08-08 11:39 +0200
        Re: Performance of unaligned memory-accesses Jorgen Grahn <grahn+nntp@snipabacken.se> - 2019-08-07 19:48 +0000
        Re: Performance of unaligned memory-accesses Keith Thompson <kst-u@mib.org> - 2019-08-07 15:51 -0700
          Re: Performance of unaligned memory-accesses David Brown <david.brown@hesbynett.no> - 2019-08-08 12:51 +0200
            Re: Performance of unaligned memory-accesses scott@slp53.sl.home (Scott Lurndal) - 2019-08-08 14:46 +0000
              Re: Performance of unaligned memory-accesses David Brown <david.brown@hesbynett.no> - 2019-08-08 17:14 +0200

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