Re: Current code for function j2date does not have the same correct dynamic range as older code.

From: Dann Corbit
Sent: Tuesday, December 11, 2007 5:58 PM
To: pgsql-hackers@postgresql.org
Subject: Current code for function j2date does not have the
same correct dynamic range as older code.

It may not matter to the PostgreSQL group, since nothing goes
wrong until the year is 1,465,002 or larger. It may also be
an artifact of the Microsoft Visual C++ compiler. At any
rate, the modular math to compute the year month and day do
not remain accurate nearly as long for the new code as the
old. The old code here is j2dateOld(), and the new code is
j2dateNew3(). I made a few tests with other internal types to
try to extend the range of the new code, but neither long long
or using mostly unsigned seems to restore the old range
because the mathematics are not identical. At any rate, here
is a unit test driver you can fiddle with, if you so choose.

Correction:
It is the new routines that are sound. The old routines had overflow
problems.

So *cough* nevermind.
[snip of code]