Red Hat Bugzilla – Bug 146447
dlamc1 never returns
Last modified: 2007-11-30 17:10:59 EST
Description of problem:
All calls made to dlamc1 subroutine of lapack never return. Try the
following test program:
INTEGER BETA, T
LOGICAL RND, IEEE1
CALL DLAMC1( BETA, T, RND, IEEE1 )
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):
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.
Recompiling the routine with current g77 and only -O option makes the
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.