Re: mingw32 floating point diff

Peter Eisentraut <peter(dot)eisentraut(at)2ndquadrant(dot)com> writes:
> On 2019-08-20 14:59, Peter Eisentraut wrote:
>> Running the regression tests on mingw32, I get the following diff in
>> circle.out:
...
> OK, the problem isn't the new output routines. The result of the
> computations is actually different. The test itself is new in PG12.
> The difference in output is due to the mingw32 target using -mfpmath=387
> by default. If you build with -mfpmath=sse -msee, the tests pass again.

Hm, so presumably we could replicate this on other Intel-oid platforms
by changing compiler switches? (I haven't tried.)

> Do we care to do anything about this? Pick slightly different test data
> perhaps?

Picking different test data might be a good "fix". Alternatively, we
could try to figure out where the discrepancy is arising and adjust
the code --- but that might be a lot more work than it's worth.

regards, tom lane