Re: Use of C99 int types

[Adrian Bunk <bunk@stusta.de>]

On Mon, Apr 04, 2005 at 12:48:04AM +0200, Dag Arne Osvik wrote:
> Andreas Schwab wrote:
> 
> >Dag Arne Osvik <da@osvik.no> writes:
> >
> > 
> >
> >>Yes, but wouldn't it be much better to avoid code like the following, 
> >>which may also be wrong (in terms of speed)?
> >>
> >>#ifdef CONFIG_64BIT  // or maybe CONFIG_X86_64?
> >>#define fast_u32 u64
> >>#else
> >>#define fast_u32 u32
> >>#endif
> >>   
> >>
> >
> >How about using just unsigned long instead?
> > 
> >
> 
> unsigned long happens to coincide with uint_fast32_t for x86 and x86-64, 
> but there's no guarantee that it will on other architectures.
>...

The stdint.h shipped with glibc says:

<--  snip  -->

/* Unsigned.  */
typedef unsigned char           uint_fast8_t;
#if __WORDSIZE == 64
typedef unsigned long int       uint_fast16_t;
typedef unsigned long int       uint_fast32_t;
typedef unsigned long int       uint_fast64_t;
#else
typedef unsigned int            uint_fast16_t;
typedef unsigned int            uint_fast32_t;
__extension__
typedef unsigned long long int  uint_fast64_t;
#endif

<--  snip  -->

>  Dag Arne

cu
Adrian

-- 

       "Is there not promise of rain?" Ling Tan asked suddenly out
        of the darkness. There had been need of rain for many days.
       "Only a promise," Lao Er said.
                                       Pearl S. Buck - Dragon Seed

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