Created attachment 359767 [details] Example program to show slowness of expf function Description of problem: Single precision expf function is 5.5x slower than double precision exp function on x86_64. Version-Release number of selected component (if applicable): glibc-2.9-3.x86_64 How reproducible: Every time Steps to Reproduce: 1. Download attached file test.f 2. gfortran test.f 3. time ./a.out Actual results: 4.4816890 real 0m28.698s user 0m28.467s sys 0m0.089s Expected results: gfortran -fdefault-real-8 test.f time ./a.out 4.4816890703380645 real 0m5.134s user 0m5.082s sys 0m0.016s Additional info: Still present in F12 alpha, glibc-2.10.90-12.x86_64. Above is simplest test case I could make. I originally noticed the problem running a 1000 line single precision code and comparing run times when compiled with g77 and gfortran. g77 calls the double precision exp function whereas gfortran calls the single precision expf function. The runtime when compiling with g77was x2 - x3 faster than using gfortran. Also noticed similar type of problems with sin function reported at: http://sources.redhat.com/bugzilla/show_bug.cgi?id=5997 and http://sourceware.org/bugzilla/show_bug.cgi?id=5781 This problem doesnt seem to show up on the 32-bit architecture.
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Fedora 10 changed to end-of-life (EOL) status on 2009-12-17. Fedora 10 is no longer maintained, which means that it will not receive any further security or bug fix updates. As a result we are closing this bug. If you can reproduce this bug against a currently maintained version of Fedora please feel free to reopen this bug against that version. Thank you for reporting this bug and we are sorry it could not be fixed.
Still present in Fedora 12 so reopening with "Version" set to "12". Changing "Status" from "CLOSED" back to "ASSIGNED".
This message is a reminder that Fedora 12 is nearing its end of life. Approximately 30 (thirty) days from now Fedora will stop maintaining and issuing updates for Fedora 12. It is Fedora's policy to close all bug reports from releases that are no longer maintained. At that time this bug will be closed as WONTFIX if it remains open with a Fedora 'version' of '12'. Package Maintainer: If you wish for this bug to remain open because you plan to fix it in a currently maintained version, simply change the 'version' to a later Fedora version prior to Fedora 12's end of life. Bug Reporter: Thank you for reporting this issue and we are sorry that we may not be able to fix it before Fedora 12 is end of life. If you would still like to see this bug fixed and are able to reproduce it against a later version of Fedora please change the 'version' of this bug to the applicable version. If you are unable to change the version, please add a comment here and someone will do it for you. Although we aim to fix as many bugs as possible during every release's lifetime, sometimes those efforts are overtaken by events. Often a more recent Fedora release includes newer upstream software that fixes bugs or makes them obsolete. The process we are following is described here: http://fedoraproject.org/wiki/BugZappers/HouseKeeping
Still present in Fedora 14 so changing "Version" set to "14".
This package has changed ownership in the Fedora Package Database. Reassigning to the new owner of this component.
Known issue with 64bit exp, upstream glibc has already made it pretty clear they're not going to change this code unless someone comes up with code that has the same accuracy.