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Message-ID: <3FBE6D21.1080305@redhat.com>
Date: Fri, 21 Nov 2003 14:53:05 -0500
From: "J. Johnston" <jjohnstn AT redhat DOT com>
Organization: Red Hat Inc.
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To: Wayne Hayes <wayne AT cs DOT toronto DOT edu>
Cc: newlib AT sources DOT redhat DOT com, cygwin AT cygwin DOT com
Subject: Re: [wayne AT cs DOT toronto DOT edu: Cygwin-1.5.5 sscanf on floats: 20 times
 slower than 2 years ago]
References: <03Nov17 DOT 130546edt DOT 453219-16291 AT jane DOT cs DOT toronto DOT edu>
In-Reply-To: <03Nov17.130546edt.453219-16291@jane.cs.toronto.edu>
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Wayne Hayes wrote:
>>Since scanf and the floating point arithmetic is implemented in newlib,
>>I've redirected this message there.  Does anybody have an idea, what
>>could slow down float scanning in sscanf by a factor of 20?
> 
> 
> Thanks!  Just to be pedentic, I realized that it's worse than a factor of 20.
> My *entire simulation* slows down by a factor of 20; there's significant
> other computation in it.  So the scanf slowdown is probably closer to
> hundreds of times.  *Something* fishy must be going on.  :-)
> 

The reason for the slow down is long double support.  A new routine _strtold is 
used instead of _strtod_r.  I am working on a patch to use the old routine for 
non-long-doubles to avoid the slow down.

-- Jeff J.


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