cobol: Changes to eliminate _Float128 from the front end [PR119241]

cobol: Changes to eliminate _Float128 from the front end [PR119241]

These changes switch _Float128 types to REAL_VALUE_TYPE in the front end.
Some __int128 variables and function return values are changed to
FIXED_WIDE_INT(128)

gcc/cobol

	PR cobol/119241
	* cdf.y: (cdfval_base_t::operator()): Return const.
	* cdfval.h: (struct cdfval_base_t): Add const cdfval_base_t&
	operator().
	(struct cdfval_t): Add cdfval_t constructor.  Change cdf_value
	definitions.
	* gcobolspec.cc (lang_specific_driver): Formatting fix.
	* genapi.cc: Include fold-const.h and realmpfr.h.
	(initialize_variable_internal): Use real_to_decimal instead of
	strfromf128.
	(get_binary_value_from_float): Use wide_int_to_tree instead of
	build_int_cst_type.
	(psa_FldLiteralN): Use fold_convert instead of strfromf128,
	real_from_string and build_real.
	(parser_display_internal): Rewritten to work on REAL_VALUE_TYPE
	rather than _Float128.
	(mh_source_is_literalN): Use FIXED_WIDE_INT(128) rather than
	__int128, wide_int_to_tree rather than build_int_cst_type,
	fold_convert rather than build_string_literal.
	(real_powi10): New function.
	(binary_initial_from_float128): Change type of last argument from
	_Float128 to REAL_VALUE_TYPE, process it using real.cc and mpfr
	APIs.
	(digits_from_float128): Likewise.
	(initial_from_float128): Make static.  Remove value argument, add
	local REAL_VALUE_TYPE value variable instead, process it using
	real.cc and native_encode_expr APIs.
	(parser_symbol_add): Adjust initial_from_float128 caller.
	* genapi.h (initial_from_float128): Remove declaration.
	* genutil.cc (get_power_of_ten): Change return type from __int128
	to FIXED_WIDE_INT(128), ditto for retval type, change type of pos
	from __int128 to unsigned long long.
	(scale_by_power_of_ten_N): Use wide_int_to_tree instead of
	build_int_cst_type.  Use FIXED_WIDE_INT(128) instead of __int128
	as power_of_ten variable type.
	(copy_little_endian_into_place): Likewise.
	* genutil.h (get_power_of_ten): Change return type from __int128
	to FIXED_WIDE_INT(128).
	* parse.y (%union): Change type of float128 from _Float128 to
	REAL_VALUE_TYPE.
	(string_of): Change argument type from _Float128 to
	const REAL_VALUE_TYPE &, use real_to_decimal rather than
	strfromf128.  Add another overload with tree argument type.
	(field: cdf): Use real_zerop rather than comparison against 0.0.
	(occurs_clause, const_value): Use real_to_integer.
	(value78): Use build_real and real_to_integer.
	(data_descr1): Use real_to_integer.
	(count): Use real_to_integer, real_from_integer and real_identical
	instead of direct comparison.
	(value_clause): Use real_from_string3 instead of num_str2i.  Use
	real_identical instead of direct comparison.  Use build_real.
	(allocate): Use real_isneg and real_iszero instead of <= 0 comparison.
	(move_tgt): Use real_to_integer, real_value_truncate,
	real_from_integer and real_identical instead of comparison of casts.
	(cce_expr): Use real_arithmetic and real_convert or real_value_negate
	instead of direct arithmetics on _Float128.
	(cce_factor): Use real_from_string3 instead of numstr2i.
	(literal_refmod_valid): Use real_to_integer.
	* symbols.cc (symbol_table_t::registers_t::registers_t): Formatting
	fix.
	(ERROR_FIELD): Likewise.
	(extend_66_capacity): Likewise.
	(cbl_occurs_t::subscript_ok): Use real_to_integer, real_from_integer
	and real_identical.
	* symbols.h (cbl_field_data_t::etc_t::value): Change type from
	_Float128 to tree.
	(cbl_field_data_t::etc_t::etc_t): Adjust defaulted argument value.
	(cbl_field_data_t::cbl_field_data_t): Formatting fix.  Use etc()
	rather than etc(0).
	(cbl_field_data_t::value_of): Change return type from _Float128 to
	tree.
	(cbl_field_data_t::operator=): Change return and argument type from
	_Float128 to tree.
	(cbl_field_data_t::valify): Use real_from_string, real_value_truncate
	and build_real.
	(cbl_field_t::same_as): Use build_zero_cst instead of _Float128(0.0).

gcc/testsuite

	* cobol.dg/literal1.cob: New testcase.
	* cobol.dg/output1.cob: Likewise

Co-authored-by: Richard Biener <rguenth@suse.de>
Co-authored-by: Jakub Jelinek <jakub@redhat.com>
Co-authored-by: James K. Lowden <jklowden@cobolworx.com>
Co-authored-by: Robert Dubner <rdubher@symas.com>