On 11/14/05, The Rasterman Carsten Haitzler <[EMAIL PROTECTED]> wrote: > On Tue, 15 Nov 2005 05:58:52 +0000 Mike Frysinger <[EMAIL PROTECTED]> babbled: > > > On Tue, Nov 15, 2005 at 06:38:33AM +0100, Vincent Torri wrote: > > > > > > maybe one should test in configure.in if the processor is an mad64 or not, > > > then define a specific flag according tot the arch and add it to the flags > > > when one compiles. > > > > gcc bugs change greatly between releases ... trying to track which CFLAGS > > are 'safe' and which ones are not is a huge pita > > > > a lot easier to say to the user: > > dont use stupid optimizations > > -funroll-loops... ummm (i just HAD to say that!) > > um.. the main problem is gcc4's amd64 build usies sse math by DEFAULT - thats > the problem.
not just gcc4, i have gcc 3.4.4 here, and it compiles sse by default. > i frankly dont know what exactly the problewm is - someone being > able to print a list of results, variables over a series of calculations and > plot the difference (errors) in them all at all stages (all intermediate > variable values too) would be useful. this is exactly what i did. i'll attach my boneheaded program and results, including binaries in case you want to disassemble or something. Hopefully it will be useful to you. Right off the bat, the first thing i notice is that all errors are introduced in divisions, but not all divisions. > i personalyl suspect its a bug in the sse > math either in the processor or compiler simply losing excess precision > somewhere - either just by the way the fpmath sse is used or by a real "silly" > bug. as the fp math seems fine on ARM (emulated fp math), ppc fp math, x87 > fpmath etc. and i dont really use extremes of the fp range in calculation as > best i know... but then again - a good analysis of the situation might be > useful. > > > -- > ------------- Codito, ergo sum - "I code, therefore I am" -------------- > The Rasterman (Carsten Haitzler) [EMAIL PROTECTED] > 裸好多 > Tokyo, Japan (東京 日本) > > > ------------------------------------------------------- > This SF.Net email is sponsored by the JBoss Inc. Get Certified Today > Register for a JBoss Training Course. Free Certification Exam > for All Training Attendees Through End of 2005. For more info visit: > http://ads.osdn.com/?ad_id=7628&alloc_id=16845&op=click > _______________________________________________ > enlightenment-devel mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/enlightenment-devel >
floattest.tar.bz2
Description: BZip2 compressed data
