Bug 146447
| Summary: | dlamc1 never returns | ||
|---|---|---|---|
| Product: | [Fedora] Fedora | Reporter: | Pawel Salek <pawsa> |
| Component: | lapack | Assignee: | Ivana Varekova <varekova> |
| Status: | CLOSED DUPLICATE | QA Contact: | |
| Severity: | medium | Docs Contact: | |
| Priority: | medium | ||
| Version: | 3 | ||
| Target Milestone: | --- | ||
| Target Release: | --- | ||
| Hardware: | i686 | ||
| OS: | Linux | ||
| URL: | http://www.theochem.kth.se/~pawsa/dlamc1.f | ||
| Whiteboard: | |||
| Fixed In Version: | Doc Type: | Bug Fix | |
| Doc Text: | Story Points: | --- | |
| Clone Of: | Environment: | ||
| Last Closed: | 2006-02-21 19:08:04 UTC | Type: | --- |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Embargoed: | |||
I seem to be unable to attach a file to the report. Anyway, the URL locates a file that contains relevant subroutines from lapack and servers as a test case. Compiling it with -O give a code that works as expected. Code compiled with -O2 will never stop. *** This bug has been marked as a duplicate of 138447 *** Changed to 'CLOSED' state since 'RESOLVED' has been deprecated. |
Description of problem: All calls made to dlamc1 subroutine of lapack never return. Try the following test program: PROGRAM aaa INTEGER BETA, T LOGICAL RND, IEEE1 CALL DLAMC1( BETA, T, RND, IEEE1 ) END This behavior is compiler dependent and does not occur when the library is compiled with lower optimization options. I cannot tell whether it is a compiler bug (I tested with native gcc-g77-3.4.2-6.fc3) or actually a bug in algorithm: it seems to do pretty ugly things and - I think - rely on IEEE arithmetics. Older gcc versions (eg. gcc-g77-3.3.3-7) do not expose the bug. Version-Release number of selected component (if applicable): lapack-3.0-25 How reproducible: Always Steps to Reproduce: 1. Compile test program with "g77 test.f -llapack -lblas" and run it Actual Results: Program will never stop. Expected Results: Program should return instantenously. Additional info: Recompiling the routine with current g77 and only -O option makes the problem dissappear.