Re: Slaying the HYPOTamus

From: Sam Mason <sam(at)samason(dot)me(dot)uk>
To: pgsql-hackers(at)postgresql(dot)org
Subject: Re: Slaying the HYPOTamus
Date: 2009-08-24 18:04:56
Message-ID: 20090824180456.GM5407@samason.me.uk
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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 just allowing it to remain correct as a result of
> changing the maths around.

I've also just realized why it's safe to return zero here; "y" contains
the smaller number and so if "x" is zero, "y" must be zero as well.

--
Sam http://samason.me.uk/

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