Xi Wang <xi.w...@gmail.com> writes:
> The reality is that C compilers are not friendly to postcondition
> checking; they consider signed integer overflow as undefined behavior,
> so they do whatever they want to do.  Even workaround options like
> -fwrapv are often broken, not to mention that they may not even have
> those options.

I think it's probably past time that we stopped guessing about this
sort of thing and added some regression test cases for it.  I'm
planning to add cases like this:

-- check sane handling of INT_MIN overflow cases
SELECT (-2147483648)::int4 * (-1)::int4;
SELECT (-2147483648)::int4 / (-1)::int4;
SELECT (-2147483648)::int4 % (-1)::int4;

                        regards, tom lane


-- 
Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-hackers

Reply via email to