Re: Simple loop with a strange output

[Adam Beneschan <adam@irvine.com>]

On Thursday, May 23, 2013 6:53:19 AM UTC-7, Luca Cappelletti wrote:

> do you know what's happening?

Overflow.

The largest possible value of an "integer" type on this platform is (2**31)-1.  So when X hits 2**30 and then you double it, the actual value, 2**31, won't fit in an integer.  If you use the right flags when compiling (I don't remember what they are), this will cause a Constraint_Error to be raised.  But since you didn't use those flags, the result will be whatever the processor returns, which will be -2**31.  Since this is less than 1099999999, it will loop back and try to double it again; now when you double it the processor will return 0, and then you get stuck in an infinite loop.

                          -- Adam