* config/i386/i386.c (ix86_function_regparm): Early exit for 64-bit;
        don't increase local_regparm with force_align_arg_pointer check.
        (ix86_function_sseregparm): Assert 32-bit.
        (type_has_variadic_args_p): New.
        (ix86_return_pops_args): Early exit for 64-bit.  Reindent; use
        type_has_variadic_args_p.
        (ix86_function_arg_regno_p): Use == 0 instead of ! test for eax.
        (init_cumulative_args): Remove TARGET_DEBUG_ARG.  Remove zero_cum;
        use memset instead.  Do maybe_vaarg check first; skip attribute
        tests if true; skip attribute tests for 64-bit.
        (construct_container): Remove TARGET_DEBUG_ARG.
        (function_arg_advance_32, function_arg_advance_64): Split out ...
        (function_arg_advance): ... from here.
        (function_arg_32, function_arg_64): Split out ...
        (function_arg): ... from here.
        (ix86_pass_by_reference): Tidy.
        (ix86_function_value_regno_p): Rearrange w/ switch on regno.
        (function_value_32): New, from parts of ix86_function_value
        and ix86_value_regno.
        (function_value_64): New, from parts of ix86_function_value
        and ix86_libcall_value.
        (ix86_function_value_1): New.
        (ix86_function_value, ix86_libcall_value): Use it.
        (return_in_memory_32, return_in_memory_64): Split out ...
        (ix86_return_in_memory): ... from here. 
        (ix86_struct_value_rtx): Skip for 64-bit.
        (ix86_libcall_value, ix86_value_regno): Remove.
        (setup_incoming_varargs_64): Split out ...
        (ix86_setup_incoming_varargs): ... from here. 
        (ix86_va_start): Remove TARGET_DEBUG_ARG.
        (legitimate_address_p, legitimize_address): Remove TARGET_DEBUG_ADDR.
        * config/i386/i386-protos.h (ix86_function_value): Remove.
        * config/i386/i386.opt (TARGET_DEBUG_ADDR, TARGET_DEBUG_ARG): Remove.

From-SVN: r123146