> Sent: Wednesday, November 13, 2024 at 8:11 PM > From: "home user via users" <users@lists.fedoraproject.org> > To: users@lists.fedoraproject.org > Cc: "home user" <mattis...@comcast.net> > Subject: Re: gcc/gsl > > On 11/13/24 11:32 AM, Patrick Dupre via users wrote: > > Hello, > > > > I am not sure this issue is entirely relevant on this mailing list. > > Maybe you could redirect me. > > > > The same application (relatively heavy code), provides different values > > when it > > is run and compiled on 2 different machines. > > Both F40 (last update) > > gcc (GCC) 14.2.1 20240912 (Red Hat 14.2.1-3) > > One > > Intel(R) Core(TM) i5-7400 CPU @ 3.00GHz > > The other one > > Intel(R) Core(TM) i7-8700 CPU @ 3.20GHz > > Actually, this happens when I use the gsl library. > > gsl-devel-2.7.1-8.fc40.x86_64 > > for integration (gsl_integration_cquad). > > Before integration, the values are strictly identical. > > The same Makefile is used. > > Now, if I copy the code generated by the machine A on machine B, > > I get the same results as it had been run on machine A. > > The size of both codes are slightly different. > > I conclude that the issue is due to the compiler. > > Indeed, the difference in the generated values seems pretty constant, > > i.e., it seems proportional to the value itself: of the order 2.7e-8 > > (relative difference) > > i.e. a lot higher than the accuracy of the machine: < 1e-35. > > > > Which one is the good one? > > Why this behavior? > > Can I solve the issue? > > > > Thank for any help. > > (just some thoughts) > > It's been a long time, but I recall that some libraries are linked in during > the build, and some (shared libraries?) are linked in at run time. Is the > gsl identical (version, size, etc.) on both machines? Is the gsl linked > during the build or at run time?
The final binary code is generated with the option -lgsl (dynamic ) > Maybe try simple math programs (a square root, a trig function, and so on), > same source code on both machines. If the answers are different, then it > seems likely to be the gsl. As I said, the maths are OK until the integration > Does the diff command confirm that source, makefile, and libraries are > identical? (Copy from one machine to the other, then do the diff.) The c code and the Makefile are strictly identical (cp -a) libraries are strictly identical > > Does the diff command confirm that input data files are identical? No input file (input parameters are in the c code). > -- > _______________________________________________ > users mailing list -- users@lists.fedoraproject.org > To unsubscribe send an email to users-le...@lists.fedoraproject.org > Fedora Code of Conduct: > https://docs.fedoraproject.org/en-US/project/code-of-conduct/ > List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines > List Archives: > https://lists.fedoraproject.org/archives/list/users@lists.fedoraproject.org > Do not reply to spam, report it: > https://pagure.io/fedora-infrastructure/new_issue > -- _______________________________________________ users mailing list -- users@lists.fedoraproject.org To unsubscribe send an email to users-le...@lists.fedoraproject.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/users@lists.fedoraproject.org Do not reply to spam, report it: https://pagure.io/fedora-infrastructure/new_issue
