Still trying to get more info, but here is what I have. Trying to build HDF5 1.7.52 on Fedora Core 5 i386 with gcc-4.1.0-3 (also seem to see it with gcc-4.1.0-4 from rawhide).
The Dataspaces (h5s) test segfaults. I've tracked it down to the following code in H5Dio.c:2263-2270 (in H5D_create_chunk_map) apparently not actually setting fm->chunk_dim: /* Decide the number of chunks in each dimension*/ for(u=0; u<f_ndims; u++) { /* Keep the size of the chunk dimensions as hsize_t for various routines */ fm->chunk_dim[u]=fm->layout->u.chunk.dim[u]; /* Round up to the next integer # of chunks, to accomodate partial chunks */ fm->chunks[u] = ((fm->f_dims[u]+dataset->shared->layout.u.chunk.dim[u])-1) / dataset->shared->layout.u.chunk.dim[u]; } /* end for */ Probably is getting optimized away for some reason. fm->chunk_dim is not reference again in H5D_create_chunk_map, but it is later on I have not been able to distill to a simple test case. Flags used to compile are the standard RPM_OPT_FLAGS for FC5: -O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector --param=ssp-buffer-size=4 -m32 -march=i386 -mtune=generic -fasynchronous-unwind-tables Flags used with 4.0.2 were: -O2 -g -pipe -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -m32 -march=i386 -mtune=penti um4 -fasynchronous-unwind-tables So there might be something there too.... -- Summary: HDF5 1.7.52 test segfaults with 4.1.0, fine with 4.0.2 (regression) Product: gcc Version: 4.1.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: orion at cora dot nwra dot com GCC host triplet: i386-redhat-linux http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26968