https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70729
--- Comment #9 from Richard Biener <rguenth at gcc dot gnu.org> ---
Oh, and I believe to make nests with only outer safelen > 0 work correctly we
need to move the check elsewhere:
Index: gcc/tree-ssa-loop-im.c
===================================================================
--- gcc/tree-ssa-loop-im.c (revision 235237)
+++ gcc/tree-ssa-loop-im.c (working copy)
@@ -2120,6 +2120,12 @@ ref_indep_loop_p_1 (struct loop *loop, i
bitmap_iterator bi;
im_mem_ref *aref;
+ /* If the Ith and the I + nth iterations can be evaluated
+ concurrently a reference with an invariant address is
+ not dependent on any other memory reference. */
+ if (loop->safelen > 0)
+ return true;
+
if (stored_p)
refs_to_check = &memory_accesses.refs_in_loop[loop->num];
else
