🚀 go-pugleaf

In comp.std.c, dik@cwi.nl (Dik T. Winter) writes:

>   What it comes down to is that << is not a mathematical operation, there
>   is nothing in mathematics that tells us that 16384 << 1 equals 32768.
>   So what is the meaning of:

I'm not so sure about that.  Conceptually, the common-usage interpretation
of the operation a << b can be represented mathematically as a*(2^b).
I can even propose a hypothetical machine that lacks a true shift instruction
and actually implements the << and >> operators by such means, especially
when b is a constant.

Given that potential implementation, it is easy to imagine that INT_MAX << 1
would generate overflow on such a machine.  Now, considering that the ANSI
standard in general places as few restrictions as possible on implementations
so as to maximize performance, I'm not sure that there is anything in the
standard that would judge this implementation as non-conforming.

Art Boyne, boyne@hplvla.lvld.hp.com
"An innocent bystander bemused by the furor of this discussion"