pr 33870 * tree.h (strcut tree_memory_tag): add field unpartitionable. remove field in_nested_struct. (struct tree_struct_field_tag): add field nesting_level. (sft_in_nested_struct): remove. (sft_nesting_level): define. (sft_unpartitionable_p): define. * tree-ssa-alias.c (mem_sym_score): if mp->var is not partitionable, return long_max. (compute_memory_partitions): do not partition sfts marked unpartitionable. (create_sft): add argument nesting_level. set sft_nesting_level with it. update all users. (create_overlap_variables_for): show nesting level. * tree-dfa.c (dump_subvars_for): likewise. (dump_variable): likewise. show whether the sft is partitionable or not. * tree-flow.h (struct fieldoff): remove field in_nested_struct. add field nesting_level. * tree-ssa-structalias.c (struct variable_info): remove field in_nested_struct. (push_fields_onto_fieldstack): add argument nesting_level. update all users. update documentation. update pair->nesting_level with nesting_level. make recursive calls with nesting_level + 1. (set_uids_in_ptset): if an sft is added to the points-to set, mark it as unpartitionable. * tree-ssa-operands.c (ref_nesting_level): new. (add_vars_for_offset): call it. add argument full_ref. update callers. if var is inside a nested structure and the nesting level of full_ref is lower than the nesting level of var, adjust offset by the offset of var. testsuite/ChangeLog PR 33870 * gcc.c-torture/execute/pr33870-1.c: New test. * gcc.dg/tree-ssa/alias-16.c: New test. From-SVN: r130141