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Re: [avr-libc-dev] New release?


From: Dmitry K.
Subject: Re: [avr-libc-dev] New release?
Date: Fri, 30 Nov 2007 16:52:19 +1000
User-agent: KMail/1.5

On Friday 30 November 2007 01:30, Weddington, Eric wrote:
[...]
> > Yes nog using -lm indeed adds the 256 bytes
>
> Oh, how interesting! So there may be a workaround? :-)
>
> Can you add that bit of information to the bug report?
>
> We usually tell users that if they are working with any floating point
> then they should always use -lm, otherwise all bets are off.
>
> Also, is there any way that you can confirm that this also works with
> the CVS version of avr-libc? Or the 1.5.x version of avr-libc? Both
> contain the new FP library.

Hi.

Has checked up with version 4.2.2. Addition of the '-lm'
option reduces the size up to 770 bytes and eliminates an
array in the RAM.  It is right: Avr-libc's conversion
functions are used, not from libgcc. It is no matter, CVS
or 1.4 branch.

Float library from Avr-libc 1.5 (or CVS) is very similar to
libgcc's one. Such thinks as subnormal numbers, negative
zero, infinities and NaNs are supported. So it is possible
to say: if you are use 1.5 branch, you can use the '-lm'
options always.

But if you are use older, 1.4 branch, you can obtain the
different results with and without '-lm' option, as the
older fplib is not correct for unnormal numbers.

Dmitry.





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