Re: Userspace compiler support of "long long"

[Randy Dunlap <randy.dunlap@oracle.com>]

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).

---
~Randy
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