http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58041
--- Comment #37 from Bernd Edlinger <bernd.edlinger at hotmail dot de> --- this version fixes the warning: --- ../gcc-4.9-20130728/gcc/testsuite/gcc.dg/torture/pr58041.c 2013-08-02 20:59:38.000000000 +0200 +++ pr58041.c 2013-08-06 18:30:51.000000000 +0200 @@ -3,8 +3,6 @@ typedef long long V __attribute__ ((vector_size (2 * sizeof (long long)), may_alias)); -typedef struct S { V v; } P __attribute__((aligned (1))); - struct s { char u; @@ -12,24 +10,24 @@ } __attribute__((packed,aligned(1))); __attribute__((noinline, noclone)) -long long foo(struct s *x, int y, V z) +long long foo(struct s *x, int y, V *z) { V a = x->v[y]; - x->v[y] = z; + x->v[y] = *z; return a[1]; } -struct s a = {0,{0,0}}; +struct s a = {0,{{0,0},{0,0}}}; int main() { V v1 = {0,1}; V v2 = {0,2}; - if (foo(&a,0,v1) != 0) + if (foo(&a,0,&v1) != 0) __builtin_abort(); - if (foo(&a,0,v2) != 1) + if (foo(&a,0,&v2) != 1) __builtin_abort(); - if (foo(&a,1,v1) != 0) + if (foo(&a,1,&v1) != 0) __builtin_abort(); return 0; }