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From: Tim Rentsch <tr.17687@z991.linuxsc.com>
Newsgroups: comp.lang.c++
Subject: Re: Performance of unaligned memory-accesses
Date: Wed, 14 Aug 2019 09:27:47 -0700
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Bonita Montero <Bonita.Montero@gmail.com> writes:

>> Again, I commented assertion that unaligned access causes undefined
>> behavior.  And I don't care what 0x3 means.
>
> 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.