Messages in this thread | | | From | nathan.zook@amd ... | Subject | RE: Linux Kernel Floating Point Emulation and CORDIC | Date | Fri, 24 Dec 1999 16:53:56 -0600 |
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EEEEEwwww! Cordic is UGLY! There is a reason that Intel & we (AMD) have gone with polyonmial & rational function approximations. BTW, our algorithms are quite accurate. If you are running in another world, or just want to emulate, look into equal-ripple approximations. You will chew some serious processor power finding good functions, but what you get can be nice.
Nathan
> -----Original Message----- > From: Arthur Jerijian [SMTP:lightmanaj@earthlink.net] > Sent: Thursday, December 23, 1999 5:58 PM > To: linux-kernel@vger.rutgers.edu > Subject: Linux Kernel Floating Point Emulation and CORDIC > > For the mathematics and theoretical computer science enthusiasts here on > this > list: > > I have taken a look at the source code of the Linux Kernel floating point > emulation engine for i386 (as of 2.2.12, don't know if it changed in > 2.3.x). I > noticed that it uses Taylor/Maclaurin polynomials to approximate the sine, > cosine, tangent, and inverse tangent functions. Wouldn't CORDIC be a > better > algorithm for computing trigonometric and exponential functions instead? > CORDIC > is a method for calculating mathematical functions using only addition, > shifting, and looking up entries in a table. More details can be found at > http://www.ezcomm.com/%7Ecyliax/Articles/RobNav/sidebar.html > > Thanks, > --Arthur > > - > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.rutgers.edu > Please read the FAQ at http://www.tux.org/lkml/
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.rutgers.edu Please read the FAQ at http://www.tux.org/lkml/
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