-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 4/9/2011 23:03, K. Frank wrote: > > What, then, would be the advantage of using decimal floating-point? > I don't really know the history or what people were thinking when > they built those early decimal floating-point systems, but there is > a (minor) advantage of having the numbers people work with on > paper being represented exactly. I have 1.2345 * 10^10, and > 7.6543 * 10^-12 written down on a piece of paper ad type them > into my decimal computer. They are represented exactly. Of > course the sum and product of these numbers is not represented > exactly (with, say, seven-digit floating-point), so any advantage > of having used decimal floating-point is minor. > > Decimal floating-point rarely buys you anything you really care about, > which is probably why almost all modern computers support binary > floating-point, but not decimal. > > This does raise the question that Ruben alluded to: Why might > someone bother with implementing a decimal floating-point package > for the gcc environment? It's a fair amount of work and rather tricky > to do it right, and if you don't do it right, there's no point to it. >
Its part of the upcoming ISO/IEC TR 24732:2009. What you use it for, or whether you will use it or not is tangent to the issue. To give a proper explanation, binary floats doesn't give the proper machine epsilon for equivalent decimal float sizes. Sure, you can cover DECIMAL64 and lower with long doubles, but what happens for DECIMAL128? I am concerned about the correctness of its implementation, and its performance implications (runtime and precession), and/or trade-offs. Right now, I opted to just map things to use the long double, its wrong but its definitely something. I haven't really got into it since I am quite busy at the moment. -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.16 (MingW32) iEYEARECAAYFAk2gkmAACgkQp56AKe10wHc8rgCfYQX+bVEV2B73q8G9i/POkwvO fAAAnR7Qkk+M1apqMaQRmA1txNYvQ3OI =O1sJ -----END PGP SIGNATURE-----
0xED74C077.asc
Description: application/pgp-keys
------------------------------------------------------------------------------ Xperia(TM) PLAY It's a major breakthrough. An authentic gaming smartphone on the nation's most reliable network. And it wants your games. http://p.sf.net/sfu/verizon-sfdev
_______________________________________________ Mingw-w64-public mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/mingw-w64-public
