Re: Target-specific Front-Ends? (Was: front end changes for altivec)

[Stan Shebs <shebs@apple.com>]

Ira Ruben wrote:
> 
> >There were some real boners,
> >such as the context sensitivity of the vector keyword, that I think
> >could have been avoided if some GCC folks had participated.
> 
> At the time the AltiVec language model was being designed gcc was
> never in the picture -- period!  The only "players" were MrC[pp] and
> Moto's Mcc (not even MW).  I'm not sure what prompted Moto to try to
> later retrofit the design into gcc.

Easy - Motorola wasn't going to be able to sell G4s to either
Linux or embedded users (VxWorks etc) without having AltiVec
support in GCC.  It speaks volumes that nobody at Motorola seemed
to be aware that GCC was Wind River's standard compiler, and
that it thus might be a good idea to talk to GCC people about the
proposed extension.

> And I don't consider the use of
> "vector" as a context-sensitive keyword a "real boner".  THAT WAS MY
> DECISION/DESIGN!

I wasn't going to mention your name, but if you want to take
credit I can't stop you... :-)

> For MrC[pp] is was easy to do.  And it was based on
> feedback from our internal (Apple) AltiVec users (the *only* users at
> that time other than Moto).  They didn't want to write __vector and
> they certainly couldn't tolerate "vector" being a macro that expanded
> to __vector (which Moto was proposing).  And "vector" couldn't be
> treated as an unconditional reserved word either.

Nevertheless, I still think it was a mistake.  When it comes to
messing with the language, we often need to say "no" to users, who
typically don't understand the consequences of tinkering with language
syntax and semantics - indeed, they're paying us to be the experts.
While it may have been easy to do in MrC, did anybody consider that
the extension was going to affect every other PowerPC compiler in
the world?  Ironically, this extension makes our internal version of
GCC more complicated and time-consuming to merge with FSF sources, so
our imports take longer and have more problems, which means that your
own daily work today has been made more difficult by the expedient
choice of several years ago.

Stan