When I compile the small program with the actual snapshot of gcc41 (20050723) I get an ICE.
Michael Cieslinski unsigned int foo () { unsigned int y[256]; unsigned int* x; for (x = y + 1; x < y + 256; ++x) *x += x[-1]; return y[0]; } gcc41h -O -ftree-vectorize -c sort.i -o sort.o sort.i: In function 'foo': sort.i:3: internal compiler error: in tree_low_cst, at tree.c:4268 Please submit a full bug report, with preprocessed source if appropriate. gcc41h -v Using built-in specs. Target: x86_64-unknown-linux-gnu Configured with: ../gcc-4.1-20050723/configure --prefix=/usr/local/gcc41h -- program-suffix=41h --with-arch=opteron --enable-languages=c,c++ --enable- checking Thread model: posix gcc version 4.1.0 20050723 (experimental) -- Summary: ICE in tree_low_cst, at tree.c:4268 with -ftree- vectorize Product: gcc Version: 4.1.0 Status: UNCONFIRMED Severity: normal Priority: P2 Component: tree-optimization AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: micis at gmx dot de CC: gcc-bugs at gcc dot gnu dot org GCC build triplet: x86_64-unknown-linux-gnu GCC host triplet: x86_64-unknown-linux-gnu GCC target triplet: x86_64-unknown-linux-gnu http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23079