decimal constants

[junky_fellow@yahoo.co.in]

Consider the following piece of code:
Note: The size of long is 64 bits on my processor.

#define MYCONSTANT 0x80000000UL

int main(void)
{
unsigned long i = 0x1000;

i &= ~MYCONSTANT;


}

My question is which is better,
#define MYCONSTANT 0x80000000UL
or
#define MYCONSTANT 0x80000000L


Thanx for any help in advance ....

[Vladimir S. Oka]

Re: decimal constants

junky_fellow@ya hoo.co.in wrote:[color=blue]
> Consider the following piece of code:
> Note: The size of long is 64 bits on my processor.
>
> #define MYCONSTANT 0x80000000UL
>
> int main(void)
> {
> unsigned long i = 0x1000;
>
> i &= ~MYCONSTANT;
>
>
> }
>
> My question is which is better,
> #define MYCONSTANT 0x80000000UL
> or
> #define MYCONSTANT 0x80000000L
>
>
> Thanx for any help in advance ....
>[/color]

Size of long being 64 bits you'd get the same result either way
(0x80000000 being the same as 0x0000000080000 000).

However, if you declare i as unsigned long, then MYCONSTANT is most
naturally a UL as well, especially if you don't want to be bitten
porting to a machine where long is shorter, and also especially if
MYCONSTANT is going to be used non-negated as well.

Cheers

Vladimir


--
My e-mail address is real, and I read it.

[Vladimir S. Oka]

Re: decimal constants

junky_fellow@ya hoo.co.in wrote:[color=blue]
> Consider the following piece of code:
> Note: The size of long is 64 bits on my processor.
>
> #define MYCONSTANT 0x80000000UL
>
> int main(void)
> {
> unsigned long i = 0x1000;
>
> i &= ~MYCONSTANT;
>
>
> }
>
> My question is which is better,
> #define MYCONSTANT 0x80000000UL
> or
> #define MYCONSTANT 0x80000000L
>
>
> Thanx for any help in advance ....
>[/color]

Size of long being 64 bits you'd get the same result either way
(0x80000000 being the same as 0x0000000080000 000).

However, if you declare i as unsigned long, then MYCONSTANT is most
naturally a UL as well, especially if you don't want to be bitten
porting to a machine where long is shorter, and also especially if
MYCONSTANT is going to be used non-negated as well.

Cheers

Vladimir


--
My e-mail address is real, and I read it.