PHP bitwise left shifting 32 spaces problem and bad results with large numbers arithmetic operations

Question

I have the following problems:

First: I am trying to do a 32-spaces bitwise left shift on a large number, and for some reason the number is always returned as-is. Fo

Answer 1

Php integer precision is limited to machine word size (32, 64). To work with arbitrary precision integers you have to store them as strings and use bc or gmp library:

   echo bcmul('516103988', bcpow(2, 32));  // 2216649749795176448