Subj : __int64 problem
To   : borland.public.cpp.borlandcpp
From : Joergen Ibsen
Date : Sun Oct 17 2004 03:27 pm

Is there a problem with applying a unary operator to the result of an 
arithmetic operation on two unsigned __int64 values?

As an example, the code:

   printf("-1     %016I64X\n",
          -( (unsigned __int64)1 ));
   printf("-(1+1) %016I64X\n",
          -( (unsigned __int64)1 + (unsigned __int64)1 ));
   printf("~1     %016I64X\n",
          ~( (unsigned __int64)1 ));
   printf("~(1+1) %016I64X\n",
          ~( (unsigned __int64)1 + (unsigned __int64)1 ));

produces:

   -1     FFFFFFFFFFFFFFFF
   -(1+1) 00000000FFFFFFFE
   ~1     FFFFFFFFFFFFFFFE
   ~(1+1) 00000000FFFFFFFD

on both the free Borland C++ 5.5.1 and Borland C++ Builder 6.

Visual C++, Pelles C, MinGW (GCC) and Digital Mars C all produce:

   -1     FFFFFFFFFFFFFFFF
   -(1+1) FFFFFFFFFFFFFFFE
   ~1     FFFFFFFFFFFFFFFE
   ~(1+1) FFFFFFFFFFFFFFFD

.