Bug#718577: libc6: Libc6/libm-2.17 almost two times slower than 2.13 in trigonometric calculations

2013-08-03 Thread Hal BugsBuster
Dear Carlos, One more time, thank you again for your quick and detailed answer... I really appreciate... I do not want to voice my opposition to changes to fix correctness over performances because this does not make sense: I fully agree on the fact that quickly obtaining false result(s) is

Bug#718577: libc6: Libc6/libm-2.17 almost two times slower than 2.13 in trigonometric calculations

2013-08-02 Thread bugsbuster
Package: libc6 Version: 2.17-7 Severity: important Dear Maintainer, * What led up to the situation? I tried to upgrade my debian testing 64 bits, based on a 3.2.0-amd64 kernel (and libc6/libm-2.13.so) to use the current testing/jessie debian based on a 3.9.8-amd64 kernel (and

Bug#718577: libc6: Libc6/libm-2.17 almost two times slower than 2.13 in trigonometric calculations

2013-08-02 Thread Carlos O'Donell
On Fri, Aug 2, 2013 at 12:10 PM, bugsbuster hal.bugsbus...@gmail.com wrote: * What led up to the situation? Upstream glibc fixed a number of correctness issues in non-default rounding modes. These correctness issues had a performance impact which has only just been fixed in 2.18. I suggest

Bug#718577: libc6: Libc6/libm-2.17 almost two times slower than 2.13 in trigonometric calculations

2013-08-02 Thread Hal BugsBuster
Hello, First of all, thank you for this quick answer and sorry for this (long) answer... However, I am not sure (sorry) to understand the full consequences of what you called a justified tradeoff... I cannot fully explain what I am doing exactly but I am working on soft real-time avionic

Bug#718577: libc6: Libc6/libm-2.17 almost two times slower than 2.13 in trigonometric calculations

2013-08-02 Thread Carlos O'Donell
On Fri, Aug 2, 2013 at 7:45 PM, Hal BugsBuster hal.bugsbus...@gmail.com wrote: I cannot fully explain what I am doing exactly but I am working on soft real-time avionic problems and the use of libm2-17 is ... IMPOSSIBLE since it multiplies by two the duration of all our computations... I'm