On 27 July 2011 12:45, Christian Weisgerber <[email protected]> wrote:
> Can PowerPC do unaligned accesses or not?
>

I'm far from an expert but I know at least some power pc can do
unalign access, like those MPC8xxx, so the socppc port can do
unaligned accesses.


> I'm bringing this up *again*, because the fragmentary dialog on ICB
> about how powerpc is supposed to behave doesn't agree with observable
> reality.
>
> | <miod> some models can afford unaligned access with a msr setting,
> | but we frown upon this and won't enable this anyway
> | <miod> so: no.
> | <deraadt> we should keep running powerpc strict align.
>
> The reality is that we *do* support unaligned accesses, at least
> on the machines people test on.  sthen@ noticed when testing the
> proposed port for snappy (Google's fast compression library) that
> unaligned accesses work fine and is reluctant to disable them in
> the port.
>
> I just noticed that archivers/xz also uses unaligned accesses on
> powerpc and nobody has complained to me that it breaks.
>
> I don't have a problem with disabling unaligned accesses in ports
> on powerpc, but without errors we are unlikely to find all of them
> and what's the justification then?
>
> --
> Christian "naddy" Weisgerber                          [email protected]

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