Re: long_int vs int byte sizes

[Corinna Vinschen <corinna-cygwin at cygwin dot com>]

On Apr  6 16:35, sisyphus1@optusnet.com.au wrote:
> -----Original Message----- From: Joseph Maxwell
> 
> >[quote]
> >int x = 0xAB78 in decimal format is : 43896
> >and
> >unsigned int y = 0xAB78 in decimal format is : 43896
> >The  size of int is 4 bytes
> >[/quote]
> >
> >Not quite what I expected, sine the leftmost bit in 'int' is 1 and
> >would be the negative flag.
> 
> No - the full 32-bit representation of 0xAB78 is:
> 
> 0000 0000 0000 0000 1010 1011 0111 1000
> 
> The leftmost bit is zero.
> 
> 
> >Note size of int and long int are the same both are 4 bytes long
> >
> >Is this to be expected?
> 
> I think so. I've not yet struck a case on Windows where either int
> or long are not 4 bytes. (Haven't tried Cygwin64.)

On x86_64 Cygwin, sizeof (long) == 8.  See
http://cygwin.com/faq/faq.html#faq.programming.64bitporting

> Certainly, on some other systems, int is 4 bytes and long is 8 bytes.
> The standards permit both configurations.

There's no standard which restricts the sizes of the datatypes in
that way.  There's only this rule to follow:

  sizeof (char) <= sizeof (short) <= sizeof (int) <= sizeof (long)


Corinna

-- 
Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Maintainer                 cygwin AT cygwin DOT com
Red Hat

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