http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50596
--- Comment #14 from vincenzo Innocente <vincenzo.innocente at cern dot ch> 2011-10-07 10:15:03 UTC --- signed char k[1024]; void foo6() { for (int i=0; i!=N; ++i) k[i] = (a[i]<b[i] ? -1 : 0) & (c[i]<d[i] ? -1 : 0); } requires -fno-tree-pre to vectorize w/o I get not vectorized: relevant stmt not supported: prephitmp.214_16 = D.2173_10 < D.2174_11 ? iftmp.2_2 : 0; btw in almost all code of mine -fno-tree-pre produces always faster code when vectorization matters!