Greg Stark wrote:
> We're implementing things like box_distance and point_distance which
> as it happens will already be doing earlier arithmetic on the doubles,
> so whatever HYPOT() does had better be consistent with that or the
> results will be just an inexplicable mishmash.
>
>
Let's look a
On Tue, Aug 25, 2009 at 1:14 AM, Tom Lane wrote:
> Paul Matthews writes:
>> Just trying to implement correct C99 behaviour here.
>
> Around here we tend to read the Single Unix Spec before C99, and SUS
> saith something different:
It doesn't seem to anticipate NaN at all.
Neither of these seems
Paul Matthews writes:
> Just trying to implement correct C99 behaviour here.
Around here we tend to read the Single Unix Spec before C99, and SUS
saith something different:
http://www.opengroup.org/onlinepubs/007908799/xsh/hypot.html
It would be serious folly for us to suppose that every platfo
Greg Stark wrote:
> Also, the question arises what should be returned for hypot(Inf,NaN)
> which your code returns Inf for. Empirically, it seems the normal
> floating point behaviour is to return NaN so I think the NaN test
> should be first.
>
>
See http://www.opengroup.org/onlinepubs/9539
On Mon, Aug 24, 2009 at 6:52 PM, David Fetter wrote:
> double hypot( double x, double y )
> {
> double yx;
>
> if( isinf(x) || isinf(y) )
> return get_float8_infinity();
>
> if( isnan(x) || isnan(y) )
> return get_float8_nan();
For what it's worth though, check out the code in float
On Mon, Aug 24, 2009 at 06:59:38PM +0100, Sam Mason wrote:
> > On Mon, Aug 24, 2009 at 11:14:19PM +1000, Paul Matthews wrote:
> > > if (x == 0.0)
> > > return 0.0;
> > > else {
> > > yx = y/x;
>
> is preventing a divide by zero on the line above. So it's not a
> performanc
On Mon, Aug 24, 2009 at 07:07:13AM -0700, David Fetter wrote:
> These next two lines are a teensy bit baroque. Is there some
> significant speed increase that would justify them?
Just noticed with your revised code that the following check:
> On Mon, Aug 24, 2009 at 11:14:19PM +1000, Paul Matthe
On Mon, Aug 24, 2009 at 12:47:42PM -0500, Kevin Grittner wrote:
> David Fetter wrote:
> > On Mon, Aug 24, 2009 at 11:14:19PM +1000, Paul Matthews wrote:
>
> > These next two lines are a teensy bit baroque. Is there some
> > significant speed increase that would justify them?
> >
> >> if (
David Fetter wrote:
> On Mon, Aug 24, 2009 at 11:14:19PM +1000, Paul Matthews wrote:
> These next two lines are a teensy bit baroque. Is there some
> significant speed increase that would justify them?
>
>> if (x == 0.0)
>> return 0.0;
>> else {
>> yx = y/x;
>>
On Mon, Aug 24, 2009 at 11:14:19PM +1000, Paul Matthews wrote:
> This is to go with the hypot() patch I posted the other day.
>
> As other code, such as found in adt/float.c and adt/numeric.c, simply
> assumes that isnan() exists, despite it being a C99 function, I have
> assumed the same.
>
> Th
This is to go with the hypot() patch I posted the other day.
As other code, such as found in adt/float.c and adt/numeric.c, simply
assumes that isnan() exists, despite it being a C99 function, I have
assumed the same.
The below code should be placed into a file called src/port/hypot.c.
Unfortuna
2009/8/23 Magnus Hagander :
> For another data point, Microsoft documentation says:
> "This POSIX function is deprecated beginning in Visual C++ 2005. Use
> the ISO C++ conformant _hypot instead."
>
> _hypot() has been there since Windows 95, so it shouldn't be a problem
> to use it - it just nee
On Sun, Aug 23, 2009 at 07:42, Tom Lane wrote:
> Greg Stark writes:
>> If there's a performance advantage then we could add a configure test
>> and define the macro to call hypot(). You said it existed before C99
>> though, how widespread was it? If it's in all the platforms we support
>> it might
Tom Lane wrote:
> Greg Stark writes:
>
>> If there's a performance advantage then we could add a configure test
>> and define the macro to call hypot(). You said it existed before C99
>> though, how widespread was it? If it's in all the platforms we support
>> it might be reasonable to just go
Greg Stark writes:
> If there's a performance advantage then we could add a configure test
> and define the macro to call hypot(). You said it existed before C99
> though, how widespread was it? If it's in all the platforms we support
> it might be reasonable to just go with it.
For one data poin
On Sun, Aug 23, 2009 at 4:54 AM, Paul Matthews wrote:
>
> The hypot() function has been part of the C standard since C99 (ie 10
> years ago)
Postgres targets C89. The date of the standard is when the standard
came out, it takes years before it's widely available and then years
again before the sys
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