According to the Borland user manual (which implements floats the same as mspgcc), a 32bit float has this range: 3.4x10^-38 to 3.4x10^38 with 7-digit precision. And after googling, I found this doc which more accurately states the precision to be 7.22 digits. http://babbage.cs.qc.edu/courses/cs341/IEEE-754references.html A good description of how it works can be found here: http://www.engr.usask.ca/~mjr347/prog/geoe314/geoe314.005b.html#float -Mark
-----Original Message----- From: mspgcc-users-ad...@lists.sourceforge.net [mailto:mspgcc-users-ad...@lists.sourceforge.net] On Behalf Of Ricardo H. Wiggers Sent: Wednesday, February 12, 2003 10:06 AM To: mspgcc-users@lists.sourceforge.net Subject: Re: [Mspgcc-users] Double data type? Correct me if i´m wrong. Using 32bit long as fixed point (Q31) I could reach a range from -1 to 0,9999999995 (=1-2^-31), wich seems to satisfy the specification. Bye, Ricardo ----- Original Message ----- From: "Bill Knight" <bi...@rosw.com> To: <mspgcc-users@lists.sourceforge.net> Sent: Wednesday, February 12, 2003 10:32 AM Subject: Re: [Mspgcc-users] Double data type? > This got me thinking (warning). Looks like values can range from > 0.00000000 to 99999999. What about using 'long long's? I think > that should cover the range. Would someone remind me, does mspgcc > have long long support? > > Anyway, just a thought. > > -Bill Knight > R O SoftWare > > > On Wed, 12 Feb 2003 08:16:15 -0500 (EST), Thomas Carley wrote: > > >Would a fixed point representation work well here? If you use base 2 > >(binary fixed point) it is very efficient. What is the range of data you > >need to represent, and with what precision? > > >On Wed, 12 Feb 2003, Dmitry wrote: > > >> 64bits doubles are not supported. > >> I have no plans to make this support. > >> > >> only 32bits IEEE754 floats are (somehow) suported. > >> > >> ~d > >> > >> > >> On Wednesday 12 February 2003 00:17, Mark Stokes wrote: > >> > What happened to the double data type that was discussed earlier. I > >> > have found a need for it and was wondering. Here's my dilemma: > >> > I am using 8-digit 7-seg display to represent things on the screen. > >> > This means that if I want to represent a floating point number that is > >> > less than one like 0.9999999 I would have a number that is out of the > >> > bounds of the "float" data type. For example: > >> > > >> > float floatvar; > >> > > >> > floatvar = 0.99999999 > >> > > >> > Then floatvar ends up == 1 which is not helping me. I need it to == > >> > .99999999 because internally the controller can't deal w/ numbers (in > >> > this particular variable) that are >= 1.0. > >> > However, if I take the same code and put on Borland, and use "double's", > >> > then I get the intended result (floatvar ends up == to 0.99999999). > >> > {footnote: if I use float in Borland the same thing happens.} > >> > > >> > Any ideas on when "double" will be available? What about a new release > >> > of the win32 executables? Perhaps I'll get the gnu tree working so that > >> > I can make win32 releases, but right now I don't have the time to mess > >> > w/ that. > >> > > >> > Thanks > >> > -Mark > >> > > >> > > >> > > >> > ------------------------------------------------------- > >> > This SF.NET email is sponsored by: > >> > SourceForge Enterprise Edition + IBM + LinuxWorld = Something 2 See! > >> > http://www.vasoftware.com > >> > _______________________________________________ > >> > Mspgcc-users mailing list > >> > Mspgcc-users@lists.sourceforge.net > >> > https://lists.sourceforge.net/lists/listinfo/mspgcc-users > >> > >> -- > >> /******************************************************************** > >> ("`-''-/").___..--''"`-._ (\ Dimmy the Wild UA1ACZ > >> `6_ 6 ) `-. ( ).`-.__.`) Enterprise Information Sys > >> (_Y_.)' ._ ) `._ `. ``-..-' Nevsky prospekt, 20 / 44 > >> _..`--'_..-_/ /--'_.' ,' Saint Petersburg, Russia > >> (il),-'' (li),' ((!.-' +7 (812) 3468202, 5585314 > >> ********************************************************************/ > >> > >> > >> > >> ------------------------------------------------------- > >> This SF.NET email is sponsored by: > >> SourceForge Enterprise Edition + IBM + LinuxWorld http://www.vasoftware.com > >> _______________________________________________ > >> Mspgcc-users mailing list > >> Mspgcc-users@lists.sourceforge.net > >> https://lists.sourceforge.net/lists/listinfo/mspgcc-users > >> > > > > >------------------------------------------------------- > >This SF.NET email is sponsored by: > >SourceForge Enterprise Edition + IBM + LinuxWorld = Something 2 See! > >http://www.vasoftware.com > >_______________________________________________ > >Mspgcc-users mailing list > >Mspgcc-users@lists.sourceforge.net > >https://lists.sourceforge.net/lists/listinfo/mspgcc-users > > > > > > ------------------------------------------------------- > This SF.NET email is sponsored by: > SourceForge Enterprise Edition + IBM + LinuxWorld = Something 2 See! > http://www.vasoftware.com > _______________________________________________ > Mspgcc-users mailing list > Mspgcc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/mspgcc-users > > > ------------------------------------------------------- This SF.NET email is sponsored by: SourceForge Enterprise Edition + IBM + LinuxWorld = Something 2 See! http://www.vasoftware.com _______________________________________________ Mspgcc-users mailing list Mspgcc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/mspgcc-users
