Re: [PATCH] Improve geometric types - Mailing list pgsql-hackers

From Tomas Vondra
Subject Re: [PATCH] Improve geometric types
Date
Msg-id 0999e487-9842-dedf-4a7d-4c8366fe7af5@2ndquadrant.com
Whole thread Raw
In response to Re: [PATCH] Improve geometric types  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers

On 09/26/2018 10:58 PM, Tom Lane wrote:
> Tomas Vondra <tomas.vondra@2ndquadrant.com> writes:
>> Hmmm, interesting. It seems both failures happen in the chunk that
>> multiplies paths with points, i.e. essentially point_mul_point. So it
>> seems most platforms end up with
> 
>>     (0,0) * (-3,4) = (-0, 0)
> 
>> while gaur apparently thinks it's (0,0). And indeed, that's what the
>> attached trivial program does - I'd bet if you run it on gaur, it'll
>> print 0.000000, not -0.000000.
> 
> Nope, no cigar:
> 
> $ gcc -Wall -O2 test.c
> $ ./a.out
> -0.000000
> 
> (I tried a couple other -O levels to see if that affected anything,
> but it didn't.)
> 

Interesting ...

> I'll try to isolate the problem more closely, but it will take awhile.
> That machine is slow :-(
> 

OK, thanks.


regards

-- 
Tomas Vondra                  http://www.2ndQuadrant.com
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services


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