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 at
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.
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.
The
David Fetter da...@fetter.org 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 12:47:42PM -0500, Kevin Grittner wrote:
David Fetter da...@fetter.org 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?
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 Matthews
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
performance hack, it's
On Mon, Aug 24, 2009 at 6:52 PM, David Fetterda...@fetter.org 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
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
Paul Matthews p...@netspace.net.au 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
On Tue, Aug 25, 2009 at 1:14 AM, Tom Lanet...@sss.pgh.pa.us wrote:
Paul Matthews p...@netspace.net.au 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
Tom Lane wrote:
Greg Stark gsst...@mit.edu 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
On Sun, Aug 23, 2009 at 07:42, Tom Lanet...@sss.pgh.pa.us wrote:
Greg Stark gsst...@mit.edu 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
2009/8/23 Magnus Hagander mag...@hagander.net:
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 -
Like some ancient precursor to the modern hypot()enuse the dreaded
ill-tempered HYPOT()amus lurks in the recesses of geo_ops.c and
geo_decls.h. And many a line of code has been swallowed by its mighty maw.
This patch replaces the HYPOT() macro with a calls to the hypot() function.
The hypot()
On Sun, Aug 23, 2009 at 4:54 AM, Paul Matthewsp...@netspace.net.au 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
Greg Stark gsst...@mit.edu 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
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