patch to shrink the size of df_refs.

[Kenneth Zadeck]

This patch makes a modest reduction in the size of df_refs.   It does
this by changing the df_ref from being a structure to a union.  There
are various fields that are not necessary for certain of the variants. 
In particular, the loc and the basic block fields are only useful for
some of the variants.  It is also true that currently the insn_info is
not useful for the artificial refs, but stevenb plans a use for that
when he does FUDS.

I spent an enormous amount of time trying to remove the regno field.   I
do not believe that this can be done even though it can be deduced from
the reg field.   The problem is that the contents of the reg is
sometimes hacked (lower_subreg and cse are cases in point).   When this
happens, it is no longer possible to update the chains for each register
since it is not possible to remove the ref from the old chain. 

I fully tested this on ia-64 and x86-64 and compiled it on ppc-32.  It
is quite likely that there are minor ports that contain "struct df_ref
*" that need to be replaced with "df_ref" which is now a typedef which
hides a pointer to a union or explicit accesses to fields that need to
now use the macros. In these cases, the fixes are very easy.   Most of
this patch are changes of that sort.   The only significant changes are
to df.h and df-scan.c which needs to really understand the layout of the
union.

I will now go out and attach the rest of this pr, and investigate why
there are so many refs. 

There is one followup to this patch that needs to be done by someone
qualified (hint honza).
It may be possible to reduce the size of the df_ref further by
reordering the fields and changing the regno and id fields to be
integers that are never larger than 32 bits, even on a 64 bit machine. 

OK to commit?

Kenny


2008-09-24  Kenneth Zadeck <zadeck@naturalbridge.com>

    PR rtl-optimization/37448
    * df.h: (df_ref_class): New enum.
    (DF_REF_TYPE_NAMES, df_ref_extract): Removed.
    (struct df_ref): Replaced with union df_ref_d.
    (df_base_ref, df_artificial_ref, df_regular_ref, df_extract_ref):
    New members of df_ref_d union.
    (DF_REF_REAL_REG, DF_REF_REGNO, DF_REF_REAL_LOC, DF_REF_REG,
    DF_REF_LOC, DF_REF_BB, DF_REF_INSN_INFO, DF_REF_INSN,
    DF_REF_CLASS, DF_REF_TYPE, DF_REF_CHAIN, DF_REF_ID, DF_REF_FLAGS,
    DF_REF_ORDER, DF_REF_IS_ARTIFICIAL, DF_REF_NEXT_REG,
    DF_REF_PREV_REG, DF_REF_EXTRACT_WIDTH, DF_REF_EXTRACT_OFFSET,
    DF_REF_EXTRACT_MODE): Replaced definition to access union
    df_ref_d.
           (DF_MWS_REG_DEF_P, DF_MWS_REG_USE_P, DF_MWS_TYPE): New macros.
    (df_scan_bb_info, df_bb_regno_first_def_find,
    df_bb_regno_last_def_find, df_find_def, df_find_use,
    df_refs_chain_dump, df_regs_chain_dump, df_ref_debug,
    debug_df_ref, df_chain_create, df_chain_unlink, df_chain_copy,
    df_ref_create, df_ref_remove, df_compute_accessed_bytes,
    df_get_artificial_defs, df_get_artificial_uses, union_defs)
    Replaced struct df_ref * with df_ref.
    * df-scan.c (df_collection_rec, df_null_ref_rec,
    df_ref_chain_delete_du_chain, df_ref_chain_delete, df_install_ref,
    df_grow_ref_info, df_ref_create, df_reg_chain_unlink,
    df_ref_compress_rec, df_ref_remove, df_ref_chain_delete_du_chain,
    df_ref_chain_delete, df_free_collection_rec, df_insn_rescan,
    df_reorganize_refs_by_reg_by_reg,
    df_reorganize_refs_by_reg_by_insn, df_reorganize_refs_by_reg,
    df_ref_change_reg_with_loc_1, df_notes_rescan, df_swap_refs,
    df_sort_and_compress_refs, df_install_ref, df_install_refs,
    df_ref_record, df_get_conditional_uses, df_get_call_refs,
    df_bb_refs_record, df_exit_block_uses_collect,
    df_record_exit_block_uses, df_reg_chain_mark,
    df_reg_chain_verify_unmarked, df_refs_verify): Replaced struct
    df_ref * with df_ref.
    (df_ref_record, df_uses_record, df_ref_create_structure): Added
    df_ref_class parameter.
    (df_scan_problem_data): Added new pools for different types of
    refs.
    (df_scan_free_internal, df_scan_alloc, df_free_ref,
    df_ref_create_structure): Processed new ref pools.
    (df_ref_create, df_notes_rescan, df_def_record_1, df_uses_record,
    df_get_call_refs, df_insn_refs_collect, df_bb_refs_collect,
    df_entry_block_defs_collect, df_exit_block_uses_collect): Added
    code to pass df_ref_class down to ref creation functions.
    (df_reg_chain_unlink, df_ref_remove, df_ref_change_reg_with_loc_1,
    df_reg_chain_mark): Use macros to hide references to df_refs.
    (df_ref_chain_change_bb): Removed.
    (df_insn_change_bb): Remove calls to df_ref_insn_change_bb.
    (df_ref_equal_p, df_ref_compare, df_ref_create_structure):
    Enhanced to understand df_ref union structure.
    * fwprop.c (local_ref_killed_between_p, use_killed_between,
    all_uses_available_at, update_df, try_fwprop_subst,
    forward_propagate_subreg, forward_propagate_and_simplify,
    forward_propagate_into, fwprop, fwprop_addr): Replaced struct
    df_ref * with df_ref.
    (use_killed_between, all_uses_available_at): Use macros to hide
    references to df_refs.
    * regstat.c (regstat_bb_compute_ri,
    regstat_bb_compute_calls_crossed): Replaced struct df_ref * with
    df_ref.
    * see.c (see_handle_relevant_defs, see_handle_relevant_uses,
    see_handle_relevant_refs, see_analyze_one_def,
    see_update_relevancy, see_propagate_extensions_to_uses): Replaced
    struct df_ref * with df_ref.
    * ra-conflict.c (record_one_conflict, clear_reg_in_live,
    global_conflicts): Replaced struct df_ref * with df_ref.
    * ddg.c (create_ddg_dep_from_intra_loop_link,
    add_cross_iteration_register_deps, build_inter_loop_deps):
    Replaced struct df_ref * with df_ref.
    (create_ddg_dep_from_intra_loop_link,
    add_cross_iteration_register_deps): Use macros to hide references
    to df_refs.
    * auto-inc-dec.c (find_inc, merge_in_block): Replaced struct
    df_ref * with df_ref.
    * df-core.c (df_bb_regno_first_def_find,
    df_bb_regno_last_def_find, df_find_def, df_find_use,
    df_refs_chain_dump, df_regs_chain_dump, df_ref_debug,
    debug_df_ref): Replaced struct df_ref * with df_ref.
    (df_mws_dump, df_ref_debug): Use macros to hide references to
    df_refs.
    * cse.c (cse_extended_basic_block): Replaced struct df_ref * with
    df_ref.
    * web.c (union_defs, entry_register, replace_ref, web_main):
    Replaced struct df_ref * with df_ref.
    (union_defs, replace_ref): Use macros to hide references to
    df_refs.
    * global.c (compute_regs_asm_clobbered, build_insn_chain):
    Replaced struct df_ref * with df_ref.
    * ifcvt.c (dead_or_predicable): Replaced struct df_ref * with
    df_ref.
    * sel-sched-ir.c (maybe_downgrade_id_to_use, setup_id_reg_sets, ):
    Replaced struct df_ref * with df_ref.
    * ira-lives.c (mark_ref_live, def_conflicts_with_inputs_p,
    mark_ref_dead, process_bb_node_lives): Replaced struct df_ref *
    with df_ref.
    * local-alloc.c (block_alloc): Replaced struct df_ref * with
    df_ref.
    * df-byte-scan.c (df_compute_accessed_bytes_extract,
    df_compute_accessed_bytes_strict_low_part,
    df_compute_accessed_bytes_subreg, df_compute_accessed_bytes):
    Replaced struct df_ref * with df_ref.
    (df_compute_accessed_bytes): Use macros to hide references to
    df_refs.
    * init-regs.c (initialize_uninitialized_regs): Replaced struct
    df_ref * with df_ref.
    * loop-invariant.c (invariant_for_use, hash_invariant_expr_1,
    check_dependency, check_dependencies, record_uses): Replaced
    struct df_ref * with df_ref.
    (invariant_for_use, check_dependency): Use macros to hide
    references to df_refs.
    * loop-iv.c (iv_analysis_loop_init, iv_get_reaching_def,
    get_biv_step_1, get_biv_step, record_iv, iv_analyze_def,
    iv_analyze, biv_p): Replaced struct df_ref * with df_ref.
    (iv_analysis_loop_init, iv_get_reaching_def): Use macros to hide
    references to df_refs.
    * ira.c (compute_regs_asm_clobbered): Replaced struct df_ref * with
df_ref.
    * combine.c (create_log_links): Replaced struct df_ref * with df_ref.
    * df-problems.c (df_rd_bb_local_compute_process_def,
    df_lr_bb_local_compute, df_live_bb_local_compute, df_chain_create,
    df_chain_unlink_1, df_chain_unlink, df_chain_copy,
    df_chain_remove_problem, df_chain_create_bb_process_use,
    df_chain_create_bb, df_chain_top_dump, df_chain_bottom_dump,
    df_byte_lr_check_regs, df_byte_lr_bb_local_compute,
    df_byte_lr_simulate_defs, df_byte_lr_simulate_uses,
    df_byte_lr_simulate_artificial_refs_at_top,
    df_byte_lr_simulate_artificial_refs_at_end, df_create_unused_note,
    df_note_bb_compute, df_note_add_problem, df_simulate_defs,
    df_simulate_uses, df_simulate_artificial_refs_at_end,
    df_simulate_artificial_refs_at_top): Replaced struct df_ref * with
df_ref.
    (df_chain_dump): Use macros to hide
    references to df_refs.
    * dce.c (mark_nonreg_stores, delete_corresponding_reg_eq_notes,
    mark_artificial_uses, mark_reg_dependencies,
    byte_dce_process_block): Replaced struct df_ref * with df_ref.

-------------- next part --------------
A non-text attachment was scrubbed...
Name: refshrink1.diff
Type: text/x-patch
Size: 143725 bytes
Desc: not available
URL: <http://gcc.gnu.org/pipermail/gcc-patches/attachments/20080925/a4f73fdb/attachment.bin>