This is the mail archive of the gsl-discuss@sourceware.org mailing list for the GSL project.
Index Nav: | [Date Index] [Subject Index] [Author Index] [Thread Index] | |
---|---|---|
Message Nav: | [Date Prev] [Date Next] | [Thread Prev] [Thread Next] |
Other format: | [Raw text] |
> Here is an interesting test case, it aborts with a "shouldn't get > here" error in extended precision but works in double precision (via > GSL_IEEE_MODE). > > Might be worth also looking at the previous case you had that went > away when changing the optimisation - did you try it in > double-precision? I could not reproduce the exact error you got, but that same test case is giving incorrect eigenvalues when gsl is compiled with -O2 with gcc 4.1.2 with single precision. When GSL_IEEE_MODE is set to double-precision, it gives correct output. If I compile libgsleigen without -O2, it gives correct output in both cases...very odd. I'm still looking into this. It may be an issue with not properly detecting when a matrix element has become negligible. When trying to debug this, I came across the following issue: when GSL_IEEE_MODE is set to double-precision, gsl_finite(GSL_POSINF) fails. I have attached a sample test program to demonstrate this: > gcc --version gcc (GCC) 4.1.2 > gcc -g -Wall -o testfin testfin.c -lgsl -lgslcblas > setenv GSL_IEEE_MODE "double-precision" > ./testfin GSL_IEEE_MODE="double-precision,trap-common" Floating exception (core dumped) > gdb testfin core ... Program terminated with signal 8, Arithmetic exception. #0 0xb7ef3578 in gsl_finite (x=inf) at infnan.c:103 103 const double y = x - x; ... > unsetenv GSL_IEEE_MODE > ./testfin s = 0 Is this a known issue? I'm trying to use gsl_finite() in testgen to better sort the eigenvalues so I can compare them to lapack if there are infinities present. Basically I'm getting segfaults all over the place whenever I try to access nans/infs in double-precision mode. Patrick Alken
Attachment:
testfin.c
Description: Text document
Index Nav: | [Date Index] [Subject Index] [Author Index] [Thread Index] | |
---|---|---|
Message Nav: | [Date Prev] [Date Next] | [Thread Prev] [Thread Next] |