Re: Userspace compiler support of "long long"

[Kyle Moffett]

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.

Cheers,
Kyle Moffett

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