re PR tree-optimization/46556 (Code size regression in struct access)

re PR tree-optimization/46556 (Code size regression in struct access)

gcc:

	PR tree-optimization/46556
	* gimple-ssa-strength-reduction.c (enum cand_kind): Add CAND_REF.
	(base_cand_map): Change to hash table.
	(base_cand_hash): New function.
	(base_cand_free): Likewise.
	(base_cand_eq): Likewise.
	(lookup_cand): Change base_cand_map to hash table.
	(find_basis_for_candidate): Likewise.
	(base_cand_from_table): Exclude CAND_REF.
	(restructure_reference): New function.
	(slsr_process_ref): Likewise.
	(find_candidates_in_block): Call slsr_process_ref.
	(dump_candidate): Handle CAND_REF.
	(base_cand_dump_callback): New function.
	(dump_cand_chains): Change base_cand_map to hash table.
	(replace_ref): New function.
	(replace_refs): Likewise.
	(analyze_candidates_and_replace): Call replace_refs.
	(execute_strength_reduction): Change base_cand_map to hash table.

gcc/testsuite:

	PR tree-optimization/46556
	* testsuite/gcc.dg/tree-ssa/slsr-27.c: New.
	* testsuite/gcc.dg/tree-ssa/slsr-28.c: New.
	* testsuite/gcc.dg/tree-ssa/slsr-29.c: New.

From-SVN: r190037