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<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Forwarded...<o:p></o:p></span></font></p>
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10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Eric - I added you to the list so you can
participate in this discussion.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>I will be flying all day tomorrow. I’ll
respond after I am back and settled.<o:p></o:p></span></font></p>
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<p class=MsoNormal><b><font size=2 face=Tahoma><span style='font-size:10.0pt;
font-family:Tahoma;font-weight:bold'>From:</span></font></b><font size=2
face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'> E M [mailto:<st1:PersonName
w:st="on">eric@sulawesi.net</st1:PersonName>] <br>
<b><span style='font-weight:bold'>Sent:</span></b> Saturday, November 11, 2006
11:17 PM<br>
<b><span style='font-weight:bold'>To:</span></b> Daniel Leuck; <st1:PersonName
w:st="on">sdl-developers@ikayzo.org</st1:PersonName><br>
<b><span style='font-weight:bold'>Cc:</span></b> <st1:PersonName w:st="on">eric@sulawesi.net</st1:PersonName><br>
<b><span style='font-weight:bold'>Subject:</span></b> RE: Couple of things</span></font><o:p></o:p></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>I am not an expert on numerical analysis, and have not worked on SDL. I
wrote some code which used and compared GMP and OpenSSL BigNum libraries, which
is my only hook into this thread...<br>
<br>
29 decimal digits of precision is equivalent to 96 binary digits of precision.
Therefore it seems reasonable to use GMP (or appropriate equivalent) with
precision set to 0x60.<br>
<br>
However, the exponent in GMP is always a word--32 or 64 bits, where the
"decimal" type is claiming 32 bits (128 - 96). So GMP in this case
would only be equivalent on 32 bit systems.<br>
<br>
GMP does not claim to conform to any specific floating point standard (much
less THE gold standard IEEE754). Nor does GMP even claim that the same
operations will give the same results on architectures with different native
word sizes.<br>
<br>
This might be a minor point if the implementation of SDL allows platforms to do
calculations to the best of their abilities, instead of with exact equivalency.
<br>
<br>
Do the Java and C# implementations give the same results when operating on 128
bit fp quantities?<br>
<br>
One route could be to restrict SDL to floats and doubles, and make this 128 bit
(C#) fp operation an extension. That way the C++ port gets off the ground
without having to worry about it :)<br>
<br>
Eric<o:p></o:p></span></font></p>
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<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>> </span></font>Also, there is
currently no portable way to implement the 128 bit decimal type in SDL C++,
that I<o:p></o:p></p>
<u1:p></u1:p></div>
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<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>> </span></font>know of, short of
bundling the GNU MP library.<o:p></o:p></p>
<u1:p></u1:p></div>
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<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>That's a tough one. Do any other
list members have suggestions? Eric? A description of the C#
decimal type is here: <a
href="http://msdn2.microsoft.com/en-US/library/364x0z75.aspx">http://msdn2.microsoft.com/en-US/library/364x0z75.aspx</a>
<u1:p></u1:p></span></font><o:p></o:p></p>
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<p class=MsoNormal><b><font size=2 face=Tahoma><span style='font-size:10.0pt;
font-family:Tahoma;font-weight:bold'>From:</span></font></b><font size=2
face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'> Jesse Weaver
[mailto:pianohacker@gmail.com] <br>
<b><span style='font-weight:bold'>Sent:</span></b> Saturday, November 11, 2006
2:41 PM<br>
<b><span style='font-weight:bold'>To:</span></b> SDL_Developers<br>
<b><span style='font-weight:bold'>Subject:</span></b> Couple of things</span></font><o:p></o:p></p>
<u1:p></u1:p></div>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>My own two cents on a couple of things:<br>
Has anyone done any testing to make sure that the .NET port works with Mono? If
this is a priority, I imagine it wouldn't be too much work, and I could compile
it on my machine.<br>
Also, there is currently no portable way to implement the 128 bit decimal type
in SDL C++, that I know of, short of bundling the GNU MP library. What should I
do?<br clear=all>
<br>
-- <br>
Jesse<br>
<br>
-----------<br>
There is a theory which states that if anybody ever discovers exactly what the
Universe is for and why it is here, it will instantly disappear and be replaced
by something even more bizarre and inexplicable. There is another theory which
states that this has already happened. - Douglas Adams, author of Hitchhiker's
Guide to the Galaxy <u1:p></u1:p><o:p></o:p></span></font></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><br>
<br>
<br>
"Those who would give up essential liberty to purchase<br>
a little temporary safety deserve neither liberty nor<br>
safety." -- B. Franklin<o:p></o:p></span></font></p>
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