https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84357
--- Comment #3 from rsandifo at gcc dot gnu.org <rsandifo at gcc dot gnu.org> --- Author: rsandifo Date: Wed Feb 14 13:14:51 2018 New Revision: 257657 URL: https://gcc.gnu.org/viewcvs?rev=257657&root=gcc&view=rev Log: 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: static void 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> gcc/ PR tree-optimization/84357 * tree-data-ref.c (object_address_invariant_in_loop_p): Check operand 1 of an ARRAY_REF too. gcc/testsuite/ PR tree-optimization/84357 * gcc.dg/vect/pr84357.c: New test. Added: trunk/gcc/testsuite/gcc.dg/vect/pr84357.c Modified: trunk/gcc/ChangeLog trunk/gcc/testsuite/ChangeLog trunk/gcc/tree-data-ref.c
