--- Comment #3 from rsandifo at gcc dot gnu.org <rsandifo at gcc dot gnu.org>
Date: Wed Feb 14 13:14:51 2018
New Revision: 257657
Check array indices in object_address_invariant_in_loop_p (PR 84357)
object_address_invariant_in_loop_p ignored ARRAY_REF indices on
the basis that:
/* Index of the ARRAY_REF was zeroed in analyze_indices, thus we only
need to check the stride and the lower bound of the reference. */
That was true back in 2007 when the code was added:
dr_analyze_indices (struct data_reference *dr, struct loop *nest)
while (handled_component_p (aref))
if (TREE_CODE (aref) == ARRAY_REF)
op = TREE_OPERAND (aref, 1);
access_fn = analyze_scalar_evolution (loop, op);
access_fn = resolve_mixers (nest, access_fn);
VEC_safe_push (tree, heap, access_fns, access_fn);
TREE_OPERAND (aref, 1) = build_int_cst (TREE_TYPE (op), 0);
aref = TREE_OPERAND (aref, 0);
but the assignment was removed a few years ago. We were therefore
treating "two->arr[i]" and "three->arr[i]" as loop invariant.
2018-02-14 Richard Sandiford <richard.sandif...@linaro.org>
* tree-data-ref.c (object_address_invariant_in_loop_p): Check
operand 1 of an ARRAY_REF too.
* gcc.dg/vect/pr84357.c: New test.