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SubjectRe: Userspace compiler support of "long long"
On Wed, 27 Jun 2007 15:57:15 -0700 Randy Dunlap wrote:

> On Wed, 27 Jun 2007 18:30:52 -0400 Kyle Moffett wrote:
>
> > On Jun 27, 2007, at 13:32:40, Adrian Bunk wrote:
> > > AFAIR the Intel compiler claims to be gcc.
> > >
> > > But these are by far not the only C compilers under Linux, and the
> > > more important points are:
> > >
> > > Is there any userspace Linux compiler that does not support "long
> > > long"?
> >
> > Don't know, but I'd guess not.
> >
> >
> > > If yes, is there any other way to tell that something is a 64bit
> > > int on 32bit architectures?
> >
> > Not that I know of. Probably the straight #else conditional is OK.
> > We should also merge up the types since *EVERY* linux architecture
> > has these same types:
> >
> > typedef signed char __s8;
> > typedef unsigned char __u8;
> > typedef signed short __s16;
> > typedef unsigned short __u16;
> > typedef signed int __s32;
> > typedef unsigned int __u32;
> >
> > Then all 64-bit archs have:
> > typedef signed long __s64;
> > typedef unsigned long __u64;
> >
> > While all 32-bit archs have:
> > typedef signed long long __s64;
> > typedef unsigned long long __u64;
> >
> > The only trick is if you care about building 32-bit compat code using
> > 64-bit linux kernel headers. In that case we should probably just
> > make all archs use "long long" for their 64-bit integers, unless
> > there's some platform I'm not remembering where "long long" is 128-
> > bits or bigger. The other benefit is that people could then just use
> > the printf format "%llu" for 64-bit integers instead of having to
> > conditionalize it all over the place.
> >
> > I'm working on a patch now.
>
> LDD3 ch. 11 says that long on Sparc64 is 32 bits.
> Same for "ppc" (don't know which power* arch. they mean by that).

Hm, I suppose that table only applies to userspace, not kernel...

---
~Randy
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