Mesa's r300 DRI driver produces incorrect output (garbles the display) if r300_state.c is compiled with -ftree-vrp (-O2 -fno-tree-vrp works fine; all files except r300_state.c can be compiled with normal -O2).
-- Summary: gcc 4.2.1 miscompiles Mesa's r300 DRI driver with - ftree-vrp Product: gcc Version: 4.2.1 Status: UNCONFIRMED Severity: normal Priority: P3 Component: tree-optimization AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: bero at arklinux dot org GCC build triplet: i586-pc-linux-gnu GCC host triplet: i586-pc-linux-gnu GCC target triplet: i586-pc-linux-gnu http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32544