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Date:      Sun, 18 Jan 1998 20:36:40 +0100 (CET)
From:      Oliver Fromme <olli@dorifer.heim3.tu-clausthal.de>
To:        freebsd-hackers@FreeBSD.ORG
Subject:   Re: New typedefs in sys/types.h
Message-ID:  <199801181936.UAA22085@dorifer.heim3.tu-clausthal.de>

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ichael K. Sanders <msanders@aros.net> wrote in list.freebsd-hackers:
 > In message <199801132239.WAA10230@awfulhak.org>, Brian Somers writes:
 > >> Well, FWIW, apparently Digital Unix has int = 32 and long = 64.
 > >
 > >As does OpenBSD/Alpha, and I believe NetBSD/Alpha.  Nobody's been 
 > >brave/stupid enough to make sizeof(int) != 4 yet !
 > 
 > Like there'd really be a whole lot of difference there... if
 > OpenBSD/alpha is that way, you're pretty safe in assuming NetBSD/alpha
 > is, since I doubt there have been many changes to that code.

I'd like to add the fact that both 32 and 64 bits are "natural"
sizes for the Alpha processor.  It can perform memory accesses
in 32 bits units as well as in 64 bits units.  It also has
special provisions to access 8 bit parts of its registers.

It's also interesting to know that DEC's C compiler for Alpha
has a special option which causes all pointer values to be
below 2^32, and even a #pragma directive to make all pointers
32 bits.  This certainly shouldn't matter for cleanly written
software, but the truth it that there is still a lot of
software which requires those options (e.g. Doom -- although
that's probably not a typical example).

To make a long story short, I'd vote for LP64, that is, 8 bit
chars, 16 bit shorts, 32 bit ints, 64 bit longs and pointers.
Maybe even 128 bit long long (BTW, the upcoming C9X standard
even legalizes "long long").

Regards
   Oliver

PS:  The width of the memory bus of modern Alphas is 128 or
256 bits -- I don't think that should be taken into account
when deciding about the size of ints.  ;-)

-- 
Oliver Fromme, Leibnizstr. 18-61, 38678 Clausthal, Germany
(Info: finger userinfo:olli@dorifer.heim3.tu-clausthal.de)



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