Our HDF5 software has been having some data conversion problem with GCC's optimization for a few years. One example is to convert data from short to int. You can find the program at
ftp://ftp.hdfgroup.uiuc.edu/pub/outgoing/slu/tmp/ctest.c When I use "gcc -O2" or "gcc -O3" to compile it, I get wrong values after the conversion. When I use "gcc -O0" or "gcc -O1", the values are correct. I'll greatly appreciate your help if you can have a look at it. -- Summary: Optimization Problem With Data Conversion Product: gcc Version: 4.1.2 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: songyulu at hdfgroup dot org http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40686