https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65270
--- Comment #12 from rguenther at suse dot de <rguenther at suse dot de> --- On Tue, 3 Mar 2015, hubicka at gcc dot gnu.org wrote: > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65270 > > --- Comment #10 from Jan Hubicka <hubicka at gcc dot gnu.org> --- > Hi, > while looking for a testcase that would trigger with tree-tail-merge (because > gimple-fold seems to also miss MEM_REF merging) I noticed following oddity: > > struct a > { > int a[100000]; > }; > typedef struct a b __attribute__ ((aligned (32))); > typedef struct a c __attribute__ ((aligned (8))); > typedef struct a d __attribute__ ((aligned (32))); > > __attribute__ ((used)) > t(b *a, int aligned, b *d) > { > int i,v; > c *ptr = a; > for (i=0;i<100000;i++) > { > ptr->a[i]++; > } > } > main() > { > } > > here the loop gets vectorized with assumed alignmen 32. > Changing declaretion to: > t(c *a, int aligned, b *d) > produces correct 8 byte alignment loop. > Alignment of the type of variable A shall not be used. Hmm. And it's correctly handled by get_object_alignment. It's the vectorizer code that does odd things here. I'll fix it.
