common.opt: Add description of the new -fgcse-after-reload flag.

common.opt: Add description of the new -fgcse-after-reload flag.

2004-03-03  Mostafa Hagog  <mustafa@il.ibm.com>

        * common.opt: Add description of the new -fgcse-after-reload flag.

        * flags.h (flag_gcse_after_reload): Declaration of global variable.

        * gcse.c (reg_used_on_edge ,reg_set_between_after_reload_p,
        reg_used_between_after_reload_p, rtx get_avail_load_store_reg,
        is_jump_table_basic_block, bb_has_well_behaved_predecessors,
        get_bb_avail_insn, hash_scan_set_after_reload,
        compute_hash_table_after_reload, eliminate_partially_redundant_loads,
        gcse_after_reload, get_bb_avail_insn): New functions to implement
        gcse-after-reload.
        (gcse_after_reload_main): New function, the main entry point to
        gcse-after-reload.

        * rtl.h (gcse_after_reload_main): Declaration of the new function.

        * opts.c (common_handle_option): Handle the -fgcse-after-reload flag.

        * toplev.c (flag_gcse_after_reload): Initialization.

        * passes.c (rest_of_handl_gcse2): Call gcse_after_reload_main.

        * params.def (PARAM_GCSE_AFTER_RELOAD_PARTIAL_FRACTION,
        PARAM_GCSE_AFTER_RELOAD_CRITICAL_FRACTION): New parameters for tuning
        the gcse after reload optimization.

        * params.h (GCSE_AFTER_RELOAD_PARTIAL_FRACTION,
        GCSE_AFTER_RELOAD_CRITICAL_FRACTION): Two macros to access the tuning
        parameters.

        * doc/invoke.texi: Documentation for the new flag gcse-after-reload.

From-SVN: r78842