On 2008-04-17 14:02:17 +0400, Alexei Sheplyakov wrote: > I don't think it's a bug. Rather, it's a wrong expectation from the > user side. You are comparing results of FP calculation done on 3 > different platforms: ix87, sse2, and MPFR, and expect them to be the > same. I think your expectation is wrong.
I agree with you, the testcase doesn't show any bug, but... > That said, I'm not really an expert. Feel free to point out which > requirements of IEEE 754 are violated. IEEE 754 allows computations to be performed in an extended precision (this is still true in the current version, IEEE 754-2008). However the long answer is more complex: the C99 language has additional requirements (5.1.2.3#12, 6.3.1.5#2 and 6.3.1.8#2[52]) and bindings (Annex F, when IEEE 754 is claimed to be supported). See upstream bug 323 for more information: http://gcc.gnu.org/bugzilla/show_bug.cgi?id=323 and in particular my comment #125: http://gcc.gnu.org/bugzilla/show_bug.cgi?id=323#c125 Since the "incorrect" result was obtained *without* optimizations, I suppose that the problem is not due to the GCC bug 323, but is due to double rounding only. So, in this case, as I've said there (in my comment #125), this is a bug in glibc: http://sourceware.org/bugzilla/show_bug.cgi?id=6981 -- Vincent Lefèvre <vinc...@vinc17.org> - Web: <http://www.vinc17.org/> 100% accessible validated (X)HTML - Blog: <http://www.vinc17.org/blog/> Work: CR INRIA - computer arithmetic / Arenaire project (LIP, ENS-Lyon) -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org
