Hi Siva, > If we consider following sample C language code : > > long long int k=0x123; > int p=1; > k = k + p << 33; > > Here the value in variable 'p' is shifted by 33 and then the result > (only 32 bit result)was promoted to 64 bit. Yes, that's correct. ((k) = ((k) + ((p) << (33)))); Using L to mark long long, and I to mark int, and @ to mark promotion: L(L(k) = L(L(k) + L@(I(I(p) << I(33))))); Also note that where int is 32-bit, doing a i << 33 is undefined behavior. It could shift to zero. It could leave the number as-is. It could shift by one. It could... DESTROY THE UNIVERSE. So be careful with that. (If shifting a 32-bit int by 33 with GCC does destroy the universe, please file a bug <http://gcc.gnu.org/bugs.html>.) > Is it an expected behavior? Yes. > Is there any way to specify in gcc to perform implicit type promotion > first and then perform operation on it (without explicit type casting). Yes. long long k=0x123; // <-- implicit promotion 0x123 --> 0x123LL long long p=1; // <-- implicit promotion 1 --> 1LL k = k + p << 33; HTH, --Eljay
