Why long long

[czerny]

I have a little question:

The long -2147483648 could be represented by 0x80000000 and fit in 32 bits, but is convertet to long long by pelles c. Why?

czerny

[CommonTater]

I think we need a little more detail...   Converted where?

[czerny]

Code: [Select]

#include <stdio.h>
 
int main(void)
{
if ((-2147483648 & 0xffffffff) > 0)     printf("positive\n");

return 0;

}

or try to print it. The compiler wants %llx

Code: [Select]

#include <stdio.h>
 
int main(void)
{
printf("%llx\n",-2147483648);
 
return 0;

}

czerny

[CommonTater]

Try it with -2147483647  and see what it does...

It might be trying to prevent an overflow.
 

Code: [Select]

#include <stdio.h>
 
int main(void)
{
 printf("%d\n",-2147483648);
 printf("%u\n",-2147483648);
 printf("%x\n",-2147483648);
 printf("%llx\n",-2147483648);
 
 return 0;
}


[czerny]

It might be trying to prevent an overflow.

czerny