* rtl.def (define_constraint, define_register_constraint)

* rtl.def (define_constraint, define_register_constraint)
	(define_memory_constraint, define_address_constraint): New MD forms.
	* gensupport.c (process_rtx): Put define_constraint etc on the
	predicate queue.
	* genpreds.c (process_define_predicate): Adjust comment.  Validate
	the name, and call validate_exp to validate the expression.
	(mark_mode_tests, write_extract_subexp): Can assume correct input.
	(write_predicate_expr): Likewise.  NAME argument no longer necessary;
	all callers changed.
	(validate_exp, needs_variable, struct constraint_data)
	(constraints_by_letter_table, first_constraint, last_constraint_ptr)
	(FOR_ALL_CONSTRAINTS, generic_constraint_letters, const_int_constraints)
	(const_dbl_constraints, constraint_max_namelen)
	(have_register_constraints, have_memory_constraints)
	(have_address_constraints, have_address_constraints)
	(have_extra_constraints, have_const_int_constraints)
	(have_const_dbl_constraints, mangle, add_constraint)
	(process_define_constraint, process_define_register_constraint)
	(write_enum_constraint_num, write_lookup_constraint)
	(write_insn_constraint_len, write_regclass_for_constraint)
	(write_constraint_satisfied_p, write_insn_const_int_ok_for_constraint)
	(write_insn_extra_memory_constraint)
	(write_insn_extra_address_constraint)
	(write_satisfies_constraint_fns): New.
	(write_tm_preds_h): If we have new-style constraint definitions,
	prototype the functions generated from them, and define the
	old constraint interface (still used by generic code) in terms of
	those functions.
	(write_insn_preds_c): If we have new-style constraint definitions,
	generate all relevant functions from those definitions.
	(main): Handle define_constraint etc.
	* genoutput.c (struct constraint_data, indep_constraints)
	(mdep_constraint_letters, constraints_by_letter_table, note_constraint)
	(mdep_constraint_len): New data structures and functions, defined
	#ifdef USE_MD_CONSTRAINTS.
	(check_constraint_len): Don't define #ifdef USE_MD_CONSTRAINTS.
	(validate_insn_alternatives): If USE_MD_CONSTRAINTS is defined,
	use new logic to validate operand constraints against constraint
	definitions.
	(main): Process define_constraint etc. if USE_MD_CONSTRAINTS is
	defined.
	* defaults.h: If none of the old-style constraint macros are
	defined, define USE_MD_CONSTRAINTS; do not provide defaults for any
	old-style macros; and poison REG_CLASS_FROM_LETTER,
	CONST_OK_FOR_LETTER_P, CONST_DOUBLE_OK_FOR_LETTER_P, and
	EXTRA_CONSTRAINT.
	* recog.c (reg_fits_class_p): If cl is NO_REGS, return 0 immediately.
	* doc/md.texi: Document new constraint-definition mechanism and the
	C interface it provides.  Remove references to old mechanism
 	elsewhere in the document.
	(Machine Constraints): Use pathnames relative to gcc directory,
	i.e. config/ARCH/FILE.  Change i386 section to refer to
	config/i386/predicates.md; update that section to match docstrings.
	* doc/tm.texi: Move all documentation of the old constraint-
	definition macros to their own section, clearly mark as obsolete.

	* config/i386/predicates.md (R, q, Q, l, a, b, c, d, S, D, A, f, t)
	(u, y, x, Y, I, J, K, L, M, N, O, G, C, e, Z): New constraint
	definitions.
	* config/i386/i386.h (REG_CLASS_FROM_LETTER, CONST_OK_FOR_LETTER_P)
	(CONST_DOUBLE_OK_FOR_LETTER_P, EXTRA_CONSTRAINT): Delete.
	* config/i386/i386.md (*movdf_nointeger): Remove stray 'H' from
	constraint strings.
	(splits and peepholes): Use satisfies_constraint_*.
	* config/i386/i386.c (memory_address_length)
	(ix86_attr_length_immediate_default): Use satisfies_constraint_*.

From-SVN: r111508