Re: [boost] [predef] Status and review results?

Subject: Re: [boost] [predef] Status and review results?
From: Rene Rivera (grafikrobot_at_[hidden])
Date: 2013-04-22 23:45:53

On Mon, Apr 22, 2013 at 10:57 AM, Petr Machata <pmachata_at_[hidden]> wrote:

> Rene Rivera <grafikrobot_at_[hidden]> writes:
>
> > Just a quick message to mention that I've finished all the review related
> > changes to the Predef library.
> > [...] browse the current documentation at <http://tinyurl.com/cqqhhev>.
>
> I noticed that HP/PA RISC architecture seems to be tied to macro
> BOOST_ARCH_PARISK.  Is that intentional, or a typo?
>

It's intentional. As, AFAIK, PA-RISC is the common name for that
architecture. And also the macros it's based on for the version information
are also PA_RISC.

> Regarding System/360 and its descendands.  A defined __s390x__ actually
> indicates z/Architecture.  If __s390__ is defined, it could be either
> System/390, or a z/Architecture.  FWIW, GCC doesn't seem to define
> __SYSC_ZARCH__ for z/Architecture machines.
>

I can't claim to know much about those.. But is __SYSC_ZARCH__ enough ro
match any z/Architecture regardless of the s390 defines? If you think those
detections are bugs.. Could you add a bug in github to that effect? -- Just
so that I don't forgot about it ;-)

> I always considered the relation betwenn z/Architecture and s390 to be
> approximately the same as between i386 and x86_64.  Maybe it would make
> sense to have an overarching is-z-system define, similar to
> BOOST_ARCH_X86?  No idea what to call it though.
>

Hm.. Perhaps. Is that a popular understanding of those architectures?

> Also, does it even make sense to add S/370 defines?  Can one actually
> meet such environment in practice?  I know that ptrace layer in Linux
> kernel recently started requiring proper setting of 31bit/24bit
> backward-compatible flag, so I don't know... maybe there are people
> actually running 24bit systems.  It just somehow seems strange ;)
>

Don't know.. Although anything is possible with emulation.

> Last, do you envision adding defines for 64-bit PowerPC?  I don't know
> the history here, apparently there's also that RS6000 business that I'm
> not familiar with at all, but FWIW, __powerpc64__ is the define on
> Linux.  Similarly to above, __powerpc__ would be defined for any
> PowerPC, 32- or 64-bit one.
>

Yes, if it seems useful to have that distinction. Although as pointed out
by others.. At some point separately detecting/defining ABI sizes might be
more apt.

I'm not out to be dogmatic or pedantic in this library.. Just to provide as
much information we can gather from existing definitions.

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