http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55573
--- Comment #8 from vincenzo Innocente <vincenzo.innocente at cern dot ch> 2012-12-03 14:32:06 UTC --- comment 7 reduced to typedef float __attribute__( ( vector_size( 4*sizeof(float) ) ) ) V4; constexpr V4 build(float x,float y, float z) { return (V4){x,y,z,0};} constexpr V4 x = build(1,0,0); and moved to PR53094 (where I think it belongs to)