* c-common.h (enum rid): Add new enumeration values of RID_SAT,

	* c-common.h (enum rid): Add new enumeration values of RID_SAT,
	RID_FRACT, and RID_ACCUM.  RID_SAT needs to be inserted before
	RID_ONEWAY, so that it can be checked in declspecs_add_type.
	(c_common_fixed_point_type_for_size): Declare.
	* c-parser.c (reswords): Add _Fract, _Accum, and _Sat.
	(c_token_starts_typename): Handle RID_FRACT, RID_ACCUM, and RID_SAT.
	(c_token_starts_declspecs): Likewise.
	(c_parser_declspecs): Likewise.
	(c_parser_attributes): Likewise.
	* c-tree.h (enum c_typespec_keyword): Add cts_fract and cts_accum.
	(c_declspecs): Add saturating_p.
	* c-decl.c (build_null_declspecs): Initialize saturating_p.
	(declspecs_add_type): Avoid using complex with _Fract, _Accum, or _Sat.
	Handle RID_SAT.
	Avoid using void, bool, char, int, float, double, _Decimal32,
	_Decimal64, _Decimal128, and complex with _Sat.
	Handle RID_FRACT and RID_ACCUM.
	Make sure _Sat is used with _Fract or _Accum.
	(finish_declspecs): Handle cts_fract and cts_accum.
	* c-common.c (fixed-value.h): New include.
	(constant_expression_warning): Handle FIXED_CST.
	(overflow_warning): Likewise.
	(warnings_for_convert_and_check): Likewise.
	(c_common_fixed_point_type_for_size): New.
	(c_common_type_for_mode): Handle fixed-point modes to
	return various saturating/non-saturating, signed/unsigned types.
	(c_common_signed_or_unsigned_type): Support fixed-point types.
	(shorten_compare): Check fixed-point zero.
	Handle FIXED_POINT_TYPE.
	(c_common_truthvalue_conversion): Handle FIXED_CST.
	Handle FIXED_POINT_TYPE.
	(c_common_nodes_and_builtins): Record builtin types for fixed-point
	types.
	(handle_mode_attribute): Handle fixed-point modes.  Need to check
	if the signness of base type and fixed-point modes are consistent.
	(handle_vector_size_attribute): Handle fixed-point modes.
	(same_scalar_type_ignoring_signedness): Handle FIXED_POINT_TYPE.
	(warn_for_div_by_zero): Check fixed-point zero.
	* c-typeck.c (c_common_type): Check FIXED_POINT_TYPE.  Build
	a common fixed-point type based on fbit, ibit, sign, and saturation.
	(build_unary_op): Allow FIXED_POINT_TYPE for CONVERT_EXPR,
	NEGATE_EXPR, TRUTH_NOT_EXPR, PREINCREMENT_EXPR, POSTINCREMENT_EXPR,
	PREDECREMENT_EXPR, and POSTDECREMENT_EXPR.
	(convert_for_assignment): Support FIXED_POINT_TYPE.
	(digest_init): Handle FIXED_POINT_TYPE.
	(build_binary_op): Support FIXED_POINT_TYPE in *_DIV_EXPR,
	TRUTH_ANDIF_EXPR, TRUTH_ORIF_EXPR, TRUTH_AND_EXPR, TRUTH_OR_EXPR,
	TRUTH_XOR_EXPR, RSHIFT_EXPR, LSHIFT_EXPR, EQ_EXPR, NE_EXPR, LE_EXPR,
	GE_EXPR, LT_EXPR, GT_EXPR.
	* target-def.h (TARGET_FIXED_POINT_SUPPORTED_P): New.
	(TARGET_INITIALIZER): Add TARGET_FIXED_POINT_SUPPORTED_P.
	* target.h (gcc_target): Add fixed_point_supported_p.
	* targhooks.c (default_scalar_mode_supported_p): Handle MODE_FRACT,
	MODE_UFRACT, MODE_ACCUM, and MODE_UACCUM.
	(default_fixed_point_supported_p): Define.
	* targhooks.h (default_fixed_point_supported_p): Declare.
	* doc/tm.texi (TARGET_FIXED_POINT_SUPPORTED_P): Add.
	* doc/install.texi (Configuration): Add --enable-fixed-point.
	* configure.ac (--enable-fixed-point): New to enable fixed-point
	arithmetic extension to C.  For mips targets, we enable it by default.
	* configure, config.in: Regenerate.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@127652 138bc75d-0d04-0410-961f-82ee72b054a4