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Date: Tue, 2 Dec 2014 16:29:08 -0800
From: Steve Kargl <sgk@troutmask.apl.washington.edu>
To: freebsd-numerics@freebsd.org
Subject: Re: bug in j0f()
Message-ID: <20141203002908.GA98589@troutmask.apl.washington.edu>
References: <20141202214325.GA94909@troutmask.apl.washington.edu>
 <20141203000941.GA98467@troutmask.apl.washington.edu>
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On Tue, Dec 02, 2014 at 04:09:41PM -0800, Steve Kargl wrote:
> On Tue, Dec 02, 2014 at 01:43:25PM -0800, Steve Kargl wrote:
> > Anyone object to the following patch?
> > 
> > Index: e_j0f.c
> > ===================================================================
> > --- e_j0f.c	(revision 275211)
> > +++ e_j0f.c	(working copy)
> > @@ -62,7 +62,7 @@
> >  	 * j0(x) = 1/sqrt(pi) * (P(0,x)*cc - Q(0,x)*ss) / sqrt(x)
> >  	 * y0(x) = 1/sqrt(pi) * (P(0,x)*ss + Q(0,x)*cc) / sqrt(x)
> >  	 */
> > -		if(ix>0x80000000) z = (invsqrtpi*cc)/sqrtf(x);
> > +		if(ix>0x4b800000) z = (invsqrtpi*cc)/sqrtf(x);
> 
> Exhaustive testing in the range 0x1p38 to 0x1p100 
> indicated at the constant should be 0x54000000.
> 

Note, a similar wrong condition exists within y0f().  I have
not tested y0f(), but propose making a similar change in y0f()
as well.

-- 
Steve