#!/usr/bin/perl -w

#
# Copyright (C) 1995-2008 University of Karlsruhe.  All right reserved.
#
# This file is part of libFirm.
#
# This file may be distributed and/or modified under the terms of the
# GNU General Public License version 2 as published by the Free Software
# Foundation and appearing in the file LICENSE.GPL included in the
# packaging of this file.
#
# Licensees holding valid libFirm Professional Edition licenses may use
# this file in accordance with the libFirm Commercial License.
# Agreement provided with the Software.
#
# This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
# WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
# PURPOSE.
#

# This script generates the C code which creates the irop's and
# their coresponding node constructors for all operations in a given spec
# so they can be used as normal firm nodes.
# Creation: 2005/10/19
# $Id$

use strict;
use Data::Dumper;

my $specfile   = $ARGV[0];
my $target_dir = $ARGV[1];
my $state      = 1;
my $cur_op     = "";
my $line_nr    = 0;

our $arch;
our $additional_opcodes;
our %nodes;
our %operands;
our %cpu;
our $default_op_attr_type;
our $default_attr_type;
our $default_cmp_attr;
our $default_copy_attr;
our %init_attr;
our $custom_init_attr_func;
our %compare_attr;
our %copy_attr;
our %reg_classes;

# include spec file

my $return;

no strict "subs";
unless ($return = do $specfile) {
	die "Fatal error: couldn't parse $specfile: $@" if $@;
	die "Fatal error: couldn't do $specfile: $!"    unless defined $return;
	die "Fatal error: couldn't run $specfile"       unless $return;
}
use strict "subs";

my $target_c = $target_dir."/gen_".$arch."_new_nodes.c.inl";
my $target_h = $target_dir."/gen_".$arch."_new_nodes.h";

if(!defined($default_attr_type)) {
	$default_attr_type = "${arch}_attr_t";
}
if(!defined(%init_attr)) {
	%init_attr = (
		"$default_attr_type" => "\tinit_${arch}_attributes(res, flags, in_reqs, exec_units, n_res);",
	);
}
if(!defined($default_cmp_attr)) {
	$default_cmp_attr = "${arch}_compare_attr";
}
if(!defined(%compare_attr)) {
	%compare_attr = (
		"${default_attr_type}" => "${default_cmp_attr}",
	);
}

# Operands are really just nodes with some special constraints, we check
# these and create new entries in the nodes hashmap
foreach my $op (keys(%operands)) {
	my %operand = %{ $operands{"$op"} };
	my %op_node;

	# constraints
	if(defined($operand{op_flags})) { die "Fatal error: operands can't have op_flags ($op)"; }
	if(defined($operand{cmp_attr})) { die "Fatal error: cmp_attr not allowed for operands ($op)"; }
	if(defined($operand{mode})) { die "Operand must not have a mode defined ($op)"; }
	if(defined($operand{out_arity})) { die "operand must not have out_arity defined ($op)"; }
	if(defined($nodes{$op})) { die "$op defined as operand and as node"; };


	foreach my $flag (keys(%operand)) {
		$op_node{$flag} = $operand{$flag};
	}
	$op_node{op_flags} = "O";
	$op_node{cmp_attr} = 'return 1;';
	$op_node{mode}     = 'mode_ANY';

	$nodes{$op} = \%op_node;
}

#print Dumper(%nodes);
#print Dumper(%operands);

# create c code file from specs

my @obst_limit_func;
my @obst_reg_reqs;
my @obst_opvar;       # stack for the "ir_op *op_<arch>_<op-name> = NULL;" statements
my @obst_get_opvar;   # stack for the get_op_<arch>_<op-name>() functions
my $obst_constructor; # stack for node constructor functions
my @obst_new_irop;    # stack for the new_ir_op calls
my @obst_enum_op;     # stack for creating the <arch>_opcode enum
my $obst_header;      # stack for function prototypes
my @obst_is_archirn;  # stack for the is_$arch_irn() function
my @obst_cmp_attr;    # stack for the compare attribute functions
my $obst_proj = "";   # stack for the pn_ numbers
my $orig_op;
my $arity;
my $cmp_attr_func;
my $temp;
my $n_opcodes = 0;    # number of opcodes
my $ARITY_VARIABLE = -1;
my $ARITY_DYNAMIC  = -2;
my %requirements = ();
my %limit_bitsets = ();
my %reg2class = ();
my %regclass2len = ();

# build register->class hashes
foreach my $class_name (keys(%reg_classes)) {
	my @class         = @{ $reg_classes{"$class_name"} };
	my $old_classname = $class_name;

	pop(@class);

	$class_name = $arch."_".$class_name;

	my $idx = 0;
	foreach (@class) {
		$reg2class{$_->{name}} = {
			"class" => $old_classname,
			"index" => $idx
		};
		$idx++;
	}

	$regclass2len{$old_classname} = $idx;
}


# for registering additional opcodes
$n_opcodes += $additional_opcodes if (defined($additional_opcodes));

$obst_header .= "void ${arch}_create_opcodes(const arch_irn_ops_t *be_ops);\n";

sub create_constructor {
	my $op   = shift;
	my $name = shift;
	my $n    = shift;
	my $on   = shift;
	my $known_mode;

	my $suffix = "";
	if ($name ne "") {
		$suffix = "_${name}";
	}

	# determine mode
	if (exists($n->{mode})) {
		$known_mode = $n->{mode};
	}

	# determine arity
	my $arity = 0;
	if(exists($n->{"arity"})) {
		$arity = $n->{"arity"};
	} elsif (exists($n->{"reg_req"}) && exists($n->{"reg_req"}{"in"})) {
		$arity = scalar(@{ $n->{"reg_req"}{"in"} });
	} elsif (exists($n->{"ins"})) {
		$arity = scalar(@{ $n->{"ins"} });
	}
	if($arity eq "variable") {
		$arity = $ARITY_VARIABLE;
	} elsif($arity eq "dynamic") {
		$arity = $ARITY_DYNAMIC;
	}

	# determine out arity
	my $out_arity = 0;
	if(exists($n->{"out_arity"})) {
		$out_arity = $n->{"out_arity"};
	} elsif (exists($n->{"reg_req"}) && exists($n->{"reg_req"}{"out"})) {
		$out_arity = scalar(@{ $n->{"reg_req"}{"out"} });
	} elsif (exists($n->{"outs"})) {
		$out_arity = scalar(@{ $n->{"outs"} });
	}
	if($out_arity eq "variable") {
		$out_arity = $ARITY_VARIABLE;
	} elsif($out_arity eq "dynamic") {
		$out_arity = $ARITY_DYNAMIC;
	}


	my $comment = $n->{"comment"};
	if(!exists($n->{"comment"})) {
		$comment = "construct ${orig_op} node";
	}
	$comment =
		"/**\n".
		" * ${comment}\n".
		" */\n";

	$obst_constructor .= $comment;

	# create constructor head
	my $complete_args = "";
	$temp             = "";

	$temp = "ir_node *new_bd_${arch}_${op}${suffix}(dbg_info *dbgi, ir_node *block";
	if (!exists($n->{"args"})) { # default args
		if ($arity == $ARITY_VARIABLE) {
			$complete_args = ", int arity, ir_node *in[]";
		} elsif ($arity == $ARITY_DYNAMIC) {
			$complete_args = "";
		} else {
			for (my $i = 0; $i < $arity; $i++) {
				my $opname = "op${i}";
				if (exists($n->{"ins"})) {
					my @ins = @{ $n->{"ins"} };
					$opname = $ins[$i];
				}

				$complete_args .= ", ir_node *${opname}";
			}
		}
		if ($out_arity == $ARITY_VARIABLE) {
			$complete_args .= ", int n_res";
		}

		if (!defined($known_mode)) {
			$complete_args .= ", ir_mode *mode";
		}
	} else { # user defined args
		for my $href (@{ $n->{"args"} }) {
			$href->{"type"} .= " " if ($href->{"type"} !~ / [*]?$/); # put a space between name and type if there is none at the end
			$complete_args  .= ", ".$href->{"type"}.$href->{"name"};
		}
	}

	# we have additional attribute arguements
	if (exists($n->{"attr"})) {
		$complete_args .= ", ".$n->{"attr"};
	}

	$temp .= "$complete_args)";
	$obst_constructor .= "${temp}\n{\n";

	$obst_header .= $comment;
	$obst_header .= "${temp};\n";

	# emit constructor code
	$temp = <<EOF;
	ir_node        *res;
	ir_op          *op      = op_${arch}_${op};
	int             flags   = 0;
	backend_info_t *info;
EOF

	if($arity == $ARITY_DYNAMIC) {
		$temp .= <<EOF;
	int             arity   = -1;
	ir_node       **in      = NULL;
EOF
	} elsif($arity == $ARITY_VARIABLE) {
	} else {
		$temp .= <<EOF;
	int             arity   = $arity;
EOF
		if($arity > 0) {
			$temp .= <<EOF;
	ir_node        *in[$arity];
EOF
		} else {
			$temp .= <<EOF;
	ir_node       **in      = NULL;
EOF
		}
	}
	if($out_arity == $ARITY_DYNAMIC) {
		$temp .= <<EOF;
	int             n_res   = -1;
EOF
	} elsif($out_arity == $ARITY_VARIABLE) {
	} else {
		$temp .= <<EOF;
	int             n_res   = ${out_arity};
EOF
	}

	if (defined($known_mode)) {
		$temp .= <<EOF;
	ir_mode        *mode    = ${known_mode};
EOF
	}

	# set up static variables for cpu execution unit assigments
	if (exists($n->{"units"})) {
		$temp .= gen_execunit_list_initializer($n->{"units"});
	} else {
		$temp .= <<EOF;
	static const be_execution_unit_t ***exec_units = NULL;
EOF
	}

	undef my $in_req_var;
	undef my $out_req_var;

	my $set_out_reqs = "";

	# set up static variables for requirements and registers
	if (exists($n->{"reg_req"})) {
		my %req = %{ $n->{"reg_req"} };
		my $idx;

		undef my @in;
		@in = @{ $req{"in"} } if (exists($req{"in"}));
		undef my @out;
		@out = @{ $req{"out"} } if exists(($req{"out"}));

		for(my $idx = 0; $idx < $#in; $idx++) {
			my $req = $in[$idx];
			generate_requirements($req, $n, "${arch}_${op}", $idx, 1);
		}
		for(my $idx = 0; $idx < $#out; $idx++) {
			my $req = $out[$idx];
			generate_requirements($req, $n, "${arch}_${op}", $idx, 0);
		}

		if (@in) {
			if($arity >= 0 && scalar(@in) != $arity) {
				die "Fatal error: Arity and number of in requirements don't match for ${op}\n";
			}

			$temp .= "\tstatic const arch_register_req_t *in_reqs[] =\n";
			$temp .= "\t{\n";
			for ($idx = 0; $idx <= $#in; $idx++) {
				my $req = $in[$idx];
				my $reqstruct = generate_requirements($req, $n, "${arch}_${op}", $idx, 1);
				$temp .= "\t\t& ${reqstruct},\n";
			}
			$temp .= "\t};\n";
		} else {
			if($arity > 0) {
				die "Fatal error: need in requirements for ${op}\n";
			}
			$temp .= "\tstatic const arch_register_req_t **in_reqs = NULL;\n";
		}

		if (@out) {
			if($out_arity >= 0 && scalar(@out) != $out_arity) {
				die "Fatal error: Out-Arity and number of out requirements don't match for ${op}\n";
			}

			for ($idx = 0; $idx <= $#out; $idx++) {
				my $req = $out[$idx];
				my $reqstruct = generate_requirements($req, $n, "${arch}_${op}", $idx, 0);
				$set_out_reqs .= <<EOF;
info->out_infos[${idx}].req = &${reqstruct};
EOF
			}
		} else {
			if($out_arity > 0) {
				die "Fatal error: need out requirements for ${op}\n";
			}
		}
	} else {
		$temp .= "\tstatic const arch_register_req_t **in_reqs = NULL;\n";
	}
	my $attr_type = $on->{attr_type};
	if(exists($n->{"init_attr"})) {
		$temp .= "\t${attr_type} *attr;\n";
	}

	$temp .= "\n";

	if($arity > 0) {
		$temp .= "\t/* construct in array */\n";
		for (my $i = 0; $i < $arity; $i++) {
			my $opname = "op${i}";
			if (exists($n->{"ins"})) {
				my @ins = @{ $n->{"ins"} };
				$opname = $ins[$i];
			}

			$temp .= "\tin[${i}] = ${opname};\n";
		}
		$temp .= "\n";
	}

	# set flags
	if (exists($n->{"irn_flags"})) {
		$temp .= "\t/* flags */\n";
		foreach my $flag (split(/\|/, $n->{"irn_flags"})) {
			if ($flag eq "R") {
				$temp .= "\tflags |= arch_irn_flags_rematerializable;\n";
			} elsif ($flag eq "N") {
				$temp .= "\tflags |= arch_irn_flags_dont_spill;\n";
			} elsif ($flag eq "F") {
				$temp .= "\tflags |= arch_irn_flags_modify_flags;\n";
			} elsif ($flag eq "J") {
				$temp .= "\t flags |= arch_irn_flags_simple_jump;\n";
			} else {
				die "Fatal error: unknown flag $flag for ${op}\n";
			}
		}
		$temp .= "\n";
	}

	# lookup init function
	my $attr_init_code = $init_attr{$attr_type};
	if(!defined($attr_init_code)) {
		die "Fatal error: Couldn't find attribute initialisation code for type '${attr_type}'";
	}
	my $custominit = "";
	if(defined($custom_init_attr_func)) {
		$custominit .= &$custom_init_attr_func($n, $on, "${arch}_${op}");
	}
	if(defined($n->{custominit})) {
		$custominit .= $n->{custominit};
	}

	$temp .= <<EOF;
	/* create node */
	assert(op != NULL);
	res = new_ir_node(dbgi, current_ir_graph, block, op, mode, arity, in);

	/* init node attributes */
	${attr_init_code}
	${custominit}
	info = be_get_info(res);
	${set_out_reqs}

EOF

	if (exists($n->{"init_attr"})) {
		$temp .= "\tattr = get_irn_generic_attr(res);\n";
		$temp .= "\t".$n->{"init_attr"}."\n";
	}

	$temp .= <<EOF;
	/* optimize node */
	res = optimize_node(res);
	irn_vrfy_irg(res, current_ir_graph);

	return res;
EOF

	$obst_constructor .= $temp;

	# close constructor function
	$obst_constructor .= "}\n\n";
}

push(@obst_enum_op, "typedef enum _${arch}_opcodes {\n");
foreach my $op (keys(%nodes)) {
	my %n        = %{ $nodes{"$op"} };
	my $known_mode;
	my $num_outs = 0;
	my $out_arity;
	my @out_flags;

	# determine arity
	$arity = 0;
	if(exists($n{"arity"})) {
		$arity = $n{"arity"};
	} elsif (exists($n{"reg_req"}) && exists($n{"reg_req"}{"in"})) {
		$arity = scalar(@{ $n{"reg_req"}{"in"} });
	} elsif (exists($n{"ins"})) {
		$arity = scalar(@{ $n{"ins"} });
	}
	if($arity eq "variable") {
		$arity = $ARITY_VARIABLE;
	} elsif($arity eq "dynamic") {
		$arity = $ARITY_DYNAMIC;
	}

	# determine out arity
	$out_arity = 0;
	if(exists($n{"out_arity"})) {
		$out_arity = $n{"out_arity"};
	} elsif (exists($n{"reg_req"}) && exists($n{"reg_req"}{"out"})) {
		$out_arity = scalar(@{ $n{"reg_req"}{"out"} });
	} elsif (exists($n{"outs"})) {
		$out_arity = scalar(@{ $n{"outs"} });
	}
	if($out_arity eq "variable") {
		$out_arity = $ARITY_VARIABLE;
	} elsif($out_arity eq "dynamic") {
		$out_arity = $ARITY_DYNAMIC;
	}

	$orig_op = $op;
	$op      = $arch."_".$op;
	$temp    = "";

	# define proj numbers and in numbers
	if (exists($n{"outs"})) {
		undef my @outs;

		@outs = @{ $n{"outs"} };
		if($out_arity >= 0 && scalar(@outs) != $out_arity) {
			die "Fatal error: Op ${op} has different number of outs and out_arity\n";
		}

		$num_outs = $#outs + 1;

		$obst_proj .= "\nenum pn_${op} {\n";

		for (my $idx = 0; $idx <= $#outs; $idx++) {
			# check, if we have additional flags annotated to out
			if ($outs[$idx] =~ /:((S|I)(\|(S|I))*)/) {
				push(@out_flags, $1);
				$outs[$idx] =~ s/:((S|I)(\|(S|I))*)//;
			}
			$obst_proj .= "\tpn_${op}_".$outs[$idx]." = ${idx},\n";
		}

		$obst_proj .= "};\n";
		# outs have names, it must be a mode_T node
		if (!defined($n{mode})) {
			$n{mode} = "mode_T";
		}
	}
	if (exists($n{"ins"})) {
		undef my @ins;

		@ins = @{ $n{"ins"} };
		if($arity >= 0 && scalar(@ins) != $arity) {
			die "Fatal error: Op ${op} has different number of ins and arity\n";
		}

		$obst_proj .= "\nenum n_$op {\n";
		for (my $idx = 0; $idx <= $#ins; $idx++) {
			$obst_proj .= "\tn_${op}_".$ins[$idx]." = ${idx},\n";
		}
		$obst_proj .= "};\n";
	}

	# Create opcode
	push(@obst_opvar, "ir_op *op_$op = NULL;\n");
	push(@obst_get_opvar, "ir_op *get_op_$op(void)         { return op_$op; }\n");
	push(@obst_get_opvar, "int    is_$op(const ir_node *n) { return get_$arch\_irn_opcode(n) == iro_$op; }\n\n");

	push(@obst_is_archirn, "is_$op(node)");

	$obst_header .= <<EOF;
extern ir_op *op_${op};
ir_op *get_op_${op}(void);
int is_${op}(const ir_node *n);
EOF

	my $attr_type= $n{attr_type};
	if(!defined($attr_type)) {
		$attr_type = $default_attr_type;
		$n{attr_type} = $attr_type;
	}

	# determine hash function
	my $hash_func;
	if (exists($n{"hash_func"})) {
		$hash_func = $n{"hash_func"};
	}

	# determine compare function
	my $cmp_attr_func;
	if (exists($n{"cmp_attr"})) {
		my $cmpcode = $n{"cmp_attr"};

		push(@obst_cmp_attr, "static int cmp_attr_$op(ir_node *a, ir_node *b) {\n");
		if($cmpcode =~ m/attr_a/) {
			push(@obst_cmp_attr, "\t${attr_type} *attr_a = get_irn_generic_attr(a);\n");
		} else {
			push(@obst_cmp_attr, "\t(void) a;\n");
		}
		if($cmpcode =~ m/attr_b/) {
			push(@obst_cmp_attr, "\t${attr_type} *attr_b = get_irn_generic_attr(b);\n");
		} else {
			push(@obst_cmp_attr, "\t(void) b;\n");
		}
		push(@obst_cmp_attr, "\t${cmpcode}\n");
		push(@obst_cmp_attr, "}\n\n");

		$cmp_attr_func = "cmp_attr_${op}";
	} else {
		if(defined($compare_attr{${attr_type}})) {
			$cmp_attr_func = $compare_attr{${attr_type}};
		} else {
			die "Fatal error: No compare function defined for ${attr_type} attributes.";
		}
	}

	my %constructors;
	if (exists($n{constructors})) {
		%constructors = %{ $n{constructors} };
	} else {
		# Create 1 default constructor
		my %constructor = ();
		foreach my $a ("comment", "ins", "outs", "args", "attr", "units",
				"reg_req", "init_attr", "irn_flags", "mode", "arity",
				"out_arity", "custominit") {
			if (defined($n{$a})) {
				$constructor{$a} = $n{$a};
			}
		}
		%constructors = ( "" => \%constructor );
	}

	foreach my $constr (keys(%constructors)) {
		my %cstr = %{ $constructors{$constr} };
		# Copy some values from outer node if they don't exists in the constr
		foreach my $a ("ins", "outs", "irn_flags", "mode", "args", "attr",
		               "custominit") {
			if (!defined($cstr{$a}) && defined($n{$a})) {
				$cstr{$a} = $n{$a};
			}
		}
		create_constructor($orig_op, $constr, \%cstr, \%n);
	}

#	if (exists($n{"rd_constructor"}) && $n{"rd_constructor"} =~ /^NONE$/i) {
#		# we explicitly skip the constructor if the specification entry says NONE
#	} else {
#		my $comment = $n{"comment"};
#		if(!exists($n{"comment"})) {
#			$comment = "construct ${orig_op} node";
#		}
#		$comment =
#			"/**\n".
#			" * ${comment}\n".
#			" */\n";
#
#		$obst_constructor .= $comment;
#
#		# create constructor head
#		my $complete_args = "";
#		$temp             = "";
#
#		$temp = "ir_node *new_bd_$op(dbg_info *db, ir_node *block";
#		if (!exists($n{"args"})) { # default args
#			if ($arity == $ARITY_VARIABLE) {
#				$complete_args = ", int arity, ir_node *in[]";
#			} elsif ($arity == $ARITY_DYNAMIC) {
#				$complete_args = "";
#			} else {
#				for (my $i = 0; $i < $arity; $i++) {
#					my $opname = "op${i}";
#					if (exists($n{"ins"})) {
#						my @ins = @{ $n{"ins"} };
#						$opname = $ins[$i];
#					}
#
#					$complete_args .= ", ir_node *${opname}";
#				}
#			}
#			if ($out_arity == $ARITY_VARIABLE) {
#				$complete_args .= ", int n_res";
#			}
#
#			if (!defined($known_mode)) {
#				$complete_args .= ", ir_mode *mode";
#			}
#		} else { # user defined args
#			for my $href (@{ $n{"args"} }) {
#				$href->{"type"} .= " " if ($href->{"type"} !~ / [*]?$/); # put a space between name and type if there is none at the end
#				$complete_args  .= ", ".$href->{"type"}.$href->{"name"};
#			}
#		}
#
#		# we have additional attribute arguements
#		if (exists($n{"attr"})) {
#			$complete_args .= ", ".$n{"attr"};
#		}
#
#		$temp .= "$complete_args)";
#		$obst_constructor .= "${temp}\n{\n";
#		$obst_header .= $comment;
#		$obst_header .= "${temp};\n";
#
#		# emit constructor code
#		if (!exists($n{"rd_constructor"})) { # default constructor
#			$temp = <<EOF;
#	ir_node        *res;
#	ir_op          *op      = op_${op};
#	int             flags   = 0;
#	backend_info_t *info;
#EOF
#
#			if($arity == $ARITY_DYNAMIC) {
#				$temp .= <<EOF;
#	int             arity   = -1;
#	ir_node       **in      = NULL;
#EOF
#			} elsif($arity == $ARITY_VARIABLE) {
#			} else {
#				$temp .= <<EOF;
#	int             arity   = $arity;
#EOF
#				if($arity > 0) {
#					$temp .= <<EOF;
#	ir_node        *in[$arity];
#EOF
#				} else {
#					$temp .= <<EOF;
#	ir_node       **in    = NULL;
#EOF
#				}
#			}
#			if($out_arity == $ARITY_DYNAMIC) {
#				$temp .= <<EOF;
#	int             n_res   = -1;
#EOF
#			} elsif($out_arity == $ARITY_VARIABLE) {
#			} else {
#				$temp .= <<EOF;
#	int             n_res   = ${out_arity};
#EOF
#			}
#
#			if (defined($known_mode)) {
#				$temp .= <<EOF;
#	ir_mode        *mode    = ${known_mode};
#EOF
#			}
#
#			# set up static variables for cpu execution unit assigments
#			if (exists($n{"units"})) {
#				$temp .= gen_execunit_list_initializer($n{"units"});
#			} else {
#				$temp .= <<EOF;
#	static const be_execution_unit_t ***exec_units = NULL;
#EOF
#			}
#
#			undef my $in_req_var;
#			undef my $out_req_var;
#
#			my $set_out_reqs = "";
#
#			# set up static variables for requirements and registers
#			if (exists($n{"reg_req"})) {
#				my %req = %{ $n{"reg_req"} };
#				my $idx;
#
#				undef my @in;
#				@in = @{ $req{"in"} } if (exists($req{"in"}));
#				undef my @out;
#				@out = @{ $req{"out"} } if exists(($req{"out"}));
#
#				for(my $idx = 0; $idx < $#in; $idx++) {
#					my $req = $in[$idx];
#					generate_requirements($req, \%n, $op, $idx, 1);
#				}
#				for(my $idx = 0; $idx < $#out; $idx++) {
#					my $req = $out[$idx];
#					generate_requirements($req, \%n, $op, $idx, 0);
#				}
#
#				if (@in) {
#					if($arity >= 0 && scalar(@in) != $arity) {
#						die "Fatal error: Arity and number of in requirements don't match for ${op}\n";
#					}
#
#					$temp .= "\tstatic const arch_register_req_t *in_reqs[] =\n";
#					$temp .= "\t{\n";
#					for ($idx = 0; $idx <= $#in; $idx++) {
#						my $req = $in[$idx];
#						my $reqstruct = generate_requirements($req, \%n, $op, $idx, 1);
#						$temp .= "\t\t& ${reqstruct},\n";
#					}
#					$temp .= "\t};\n";
#				} else {
#					if($arity > 0) {
#						die "Fatal error: need in requirements for ${op}\n";
#					}
#					$temp .= "\tstatic const arch_register_req_t **in_reqs = NULL;\n";
#				}
#
#				if (@out) {
#					if($out_arity >= 0 && scalar(@out) != $out_arity) {
#						die "Fatal error: Out-Arity and number of out requirements don't match for ${op}\n";
#					}
#
#					for ($idx = 0; $idx <= $#out; $idx++) {
#						my $req = $out[$idx];
#						my $reqstruct = generate_requirements($req, \%n, $op, $idx, 0);
#						$set_out_reqs .= <<EOF;
#	info->out_infos[${idx}].req = &${reqstruct};
#EOF
#					}
#				} else {
#					if($out_arity > 0) {
#						die "Fatal error: need out requirements for ${op}\n";
#					}
#				}
#			} else {
#				$temp .= "\tstatic const arch_register_req_t **in_reqs = NULL;\n";
#			}
#			if(exists($n{"init_attr"})) {
#				$temp .= "\t${attr_type} *attr;\n";
#			}
#
#			$temp .= "\n";
#
#			if($arity > 0) {
#				$temp .= "\t/* construct in array */\n";
#				for (my $i = 0; $i < $arity; $i++) {
#					my $opname = "op${i}";
#					if (exists($n{"ins"})) {
#						my @ins = @{ $n{"ins"} };
#						$opname = $ins[$i];
#					}
#
#					$temp .= "\tin[${i}] = ${opname};\n";
#				}
#				$temp .= "\n";
#			}
#
#			# set flags
#			if (exists($n{"irn_flags"})) {
#				$temp .= "\t/* flags */\n";
#				foreach my $flag (split(/\|/, $n{"irn_flags"})) {
#					if ($flag eq "R") {
#						$temp .= "\tflags |= arch_irn_flags_rematerializable;\n";
#					} elsif ($flag eq "N") {
#						$temp .= "\tflags |= arch_irn_flags_dont_spill;\n";
#					} elsif ($flag eq "J") {
#						$temp .= "\t flags |= arch_irn_flags_simple_jump;\n";
#					} else {
#						die "Fatal error: unknown flag $flag for ${op}\n";
#					}
#				}
#				$temp .= "\n";
#			}
#
#			# lookup init function
#			my $attr_init_code = $init_attr{$attr_type};
#			if(!defined($attr_init_code)) {
#				die "Fatal error: Couldn't find attribute initialisation code for type '${attr_type}'";
#			}
#			my $custominit = "";
#			if(defined($custom_init_attr_func)) {
#				$custominit .= &$custom_init_attr_func(\%n, $op);
#			}
#
#			$temp .= <<EOF;
#	/* create node */
#	assert(op != NULL);
#	res = new_ir_node(db, current_ir_graph, block, op, mode, arity, in);
#
#	/* init node attributes */
#	${attr_init_code}
#	${custominit}
#	info = be_get_info(res);
#	${set_out_reqs}
#
#EOF
#
#			if (exists($n{"init_attr"})) {
#				$temp .= "\tattr = get_irn_generic_attr(res);\n";
#				$temp .= "\t".$n{"init_attr"}."\n";
#			}
#
#			$temp .= <<EOF;
#	/* optimize node */
#	res = optimize_node(res);
#	irn_vrfy_irg(res, current_ir_graph);
#
#	return res;
#EOF
#
#			$obst_constructor .= $temp;
#		}
#		else { # user defined constructor
#			$obst_constructor .= $n{"rd_constructor"};
#		}
#
#		# close constructor function
#		$obst_constructor .= "}\n\n";
#	} # constructor creation

	# set default values for state and flags if not given
	$n{"state"}    = "floats" if (! exists($n{"state"}));
	$n{"op_flags"} = "N"      if (! exists($n{"op_flags"}));


	push(@obst_new_irop, "\n\tmemset(&ops, 0, sizeof(ops));\n");
	push(@obst_new_irop, "\tops.be_ops        = be_ops;\n");
	push(@obst_new_irop, "\tops.dump_node     = $arch\_dump_node;\n");

	if (defined($cmp_attr_func)) {
		push(@obst_new_irop, "\tops.node_cmp_attr = ${cmp_attr_func};\n");
	}
	my $copy_attr_func = $copy_attr{$attr_type};
	if (!defined($copy_attr_func)) {
		$copy_attr_func = $default_copy_attr;
	}
	if (defined($copy_attr_func)) {
		push(@obst_new_irop, "\tops.copy_attr = ${copy_attr_func};\n");
	}
	if (defined($hash_func)) {
		push(@obst_new_irop, "\tops.hash = ${hash_func};\n");
	}

	$n_opcodes++;
	$temp  = "\top_$op = new_ir_op(cur_opcode + iro_$op, \"$op\", op_pin_state_".$n{"state"}.", ".$n{"op_flags"};
	$temp .= "|M, ".translate_arity($arity).", 0, sizeof(${attr_type}), &ops);\n";
	push(@obst_new_irop, $temp);
	push(@obst_new_irop, "\tset_op_tag(op_$op, $arch\_op_tag);\n");
	if(defined($default_op_attr_type)) {
		push(@obst_new_irop, "\tattr = &attrs[iro_$op];\n");
		if(defined($n{op_attr_init})) {
			push(@obst_new_irop, "\t".$n{op_attr_init}."\n");
		}
		push(@obst_new_irop, "\tset_op_attr(op_$op, attr);\n");
	}

	push(@obst_enum_op, "\tiro_$op,\n");

	$obst_header .= "\n";
}
push(@obst_enum_op, "\tiro_$arch\_last_generated,\n");
push(@obst_enum_op, "\tiro_$arch\_last = iro_$arch\_last_generated");
push(@obst_enum_op, " + $additional_opcodes") if (defined($additional_opcodes));
push(@obst_enum_op, "\n} $arch\_opcodes;\n\n");

# emit the code

open(OUT, ">$target_c") || die("Fatal error: Could not open $target_c, reason: $!\n");

print OUT "#include \"gen_$arch\_regalloc_if.h\"\n\n";
print OUT @obst_cmp_attr;
print OUT "\n";
print OUT @obst_opvar;
print OUT "\n";
print OUT @obst_get_opvar;
print OUT "\n";

print OUT<<EOF;

static int $arch\_opcode_start = -1;
static int $arch\_opcode_end   = -1;

EOF

# build the FOURCC arguments from $arch

my ($a, $b, $c, $d) = ('\0', '\0', '\0', '\0');

if (length($arch) >= 1) {
	$a = uc(substr($arch, 0, 1));
}

if (length($arch) >= 2) {
	$b = uc(substr($arch, 1, 1));
}

if (length($arch) >= 3) {
	$c = uc(substr($arch, 2, 1));
}

if (length($arch) >= 4) {
	$d = uc(substr($arch, 3, 1));
}

print OUT<<ENDOFISIRN;

/** A tag for the $arch opcodes. Note that the address is used as a tag value, NOT the FOURCC code. */
#define $arch\_op_tag FOURCC('$a', '$b', '$c', '$d')

/** Return the opcode number of the first $arch opcode. */
int get_$arch\_opcode_first(void) {
	return $arch\_opcode_start;
}

/** Return the opcode number of the last $arch opcode + 1. */
int get_$arch\_opcode_last(void) {
	return $arch\_opcode_end;
}

/** Return 1 if the given opcode is a $arch machine op, 0 otherwise */
int is_$arch\_op(const ir_op *op) {
	return get_op_tag(op) == $arch\_op_tag;
}

/** Return 1 if the given node is a $arch machine node, 0 otherwise */
int is_$arch\_irn(const ir_node *node) {
	return is_$arch\_op(get_irn_op(node));
}

int get_$arch\_irn_opcode(const ir_node *node) {
	if (is_$arch\_irn(node))
		return get_irn_opcode(node) - $arch\_opcode_start;
	return -1;
}

ENDOFISIRN

print OUT <<END;
#ifdef BIT
#undef BIT
#endif
#define BIT(x)  (1 << (x % 32))

END

print OUT @obst_limit_func;
print OUT "\n";

print OUT @obst_reg_reqs;
print OUT "\n";

print OUT<<ENDOFMAIN;
$obst_constructor

/**
 * Creates the $arch specific Firm machine operations
 * needed for the assembler irgs.
 */
void $arch\_create_opcodes(const arch_irn_ops_t *be_ops) {
#define N   irop_flag_none
#define L   irop_flag_labeled
#define C   irop_flag_commutative
#define X   irop_flag_cfopcode
#define I   irop_flag_ip_cfopcode
#define F   irop_flag_fragile
#define Y   irop_flag_forking
#define H   irop_flag_highlevel
#define c   irop_flag_constlike
#define K   irop_flag_keep
#define M   irop_flag_machine
#define O   irop_flag_machine_op
#define NB  irop_flag_dump_noblock
#define NI  irop_flag_dump_noinput
#define n   irop_flag_cse_neutral
#define R   (irop_flag_user << 0)

	ir_op_ops  ops;
	int        cur_opcode;
	static int run_once = 0;
ENDOFMAIN

	if (defined($default_op_attr_type)) {
		print OUT "\t$default_op_attr_type *attr, *attrs;\n";
	}

print OUT<<ENDOFMAIN;

	if (run_once)
		return;
	run_once = 1;

	cur_opcode = get_next_ir_opcodes(iro_$arch\_last);

	$arch\_opcode_start = cur_opcode;
ENDOFMAIN

	if (defined($default_op_attr_type)) {
		print OUT "\tattrs = xmalloc(sizeof(attr[0]) * iro_$arch\_last);\n";
		print OUT "\tmemset(attrs, 0, sizeof(attr[0]) * iro_$arch\_last);\n";
	}

print OUT @obst_new_irop;
print OUT "\n";
print OUT "\t$arch\_register_additional_opcodes(cur_opcode);\n" if (defined($additional_opcodes));
print OUT "\t$arch\_opcode_end = cur_opcode + iro_$arch\_last";
print OUT " + $additional_opcodes" if (defined($additional_opcodes));
print OUT ";\n";
print OUT "}\n";

close(OUT);

open(OUT, ">$target_h") || die("Fatal error: Could not open $target_h, reason: $!\n");

my $creation_time = localtime(time());
my $tmp = uc($arch);

print OUT<<EOF;
/**
 * \@file
 * \@brief Function prototypes for the new opcode functions.
 * \@note  DO NOT EDIT THIS FILE, your changes will be lost.
 *        Edit $specfile instead.
 *        created by: $0 $specfile $target_dir
 * \@date  $creation_time
 */
#ifndef FIRM_BE_${tmp}_GEN_${tmp}_NEW_NODES_H
#define FIRM_BE_${tmp}_GEN_${tmp}_NEW_NODES_H

EOF

print OUT @obst_enum_op;
print OUT <<EOF;
int is_${arch}_irn(const ir_node *node);
int is_${arch}_op(const ir_op *op);

int get_${arch}_opcode_first(void);
int get_${arch}_opcode_last(void);
int get_${arch}_irn_opcode(const ir_node *node);
${obst_header}
${obst_proj}

#endif
EOF

close(OUT);

###
# Translates numeric arity into string constant.
###
sub translate_arity {
	my $arity = shift;

	if ($arity =~ /^\d+$/) {
		if    ($arity == 0) {
			return "oparity_zero";
		}
		elsif ($arity == 1) {
			return "oparity_unary";
		}
		elsif ($arity == 2) {
			return "oparity_binary";
		}
		elsif ($arity == 3) {
			return "oparity_trinary";
		}
		else {
			return "oparity_any";
		}
	} elsif ($arity == $ARITY_VARIABLE) {
		return "oparity_variable";
	} elsif ($arity == $ARITY_DYNAMIC) {
		return "oparity_dynamic";
	} else {
		die "Fatal error: Unknown arity $arity";
	}
}

###
# Return the list of pointers for the given execution units.
###
sub gen_execunit_list_initializer {
	my $units   = shift;
	my $uc_arch = uc($arch);
	my $ret     = "";
	my $ret2    = "";
	my %init;

	foreach my $unit (@{ $units }) {
		if ($unit eq "DUMMY") {
			push(@{ $init{"DUMMY"} }, "\t\t&be_machine_execution_units_DUMMY[0]");
		}
		elsif (exists($cpu{"$unit"})) {
			# operation can be executed on all units of this type
			# -> add them all
			my $tp_name = "$arch\_execution_units_$unit";
			my $idx     = 0;
			foreach (@{ $cpu{"$unit"} }) {
				next if ($idx++ == 0);  # skip first element (it's not a unit)
				my $unit_name = "$uc_arch\_EXECUNIT_TP_$unit\_$_";
				push(@{ $init{"$unit"} }, "\t\t&".$tp_name."[".$unit_name."]");
			}
		}
		else {
			# operation can be executed only a certain unit
			# -> find corresponding unit type
			my $found = 0;
TP_SEARCH:	foreach my $cur_type (keys(%cpu)) {
				foreach my $cur_unit (@{ $cpu{"$cur_type"} }) {
					if ($unit eq $cur_unit) {
						my $tp_name   = "$arch\_execution_units_$cur_type";
						my $unit_name = "$uc_arch\_EXECUNIT_TP_$cur_type\_$unit";
						push(@{ $init{"$unit"} }, "\t\t&".$tp_name."[".$unit_name."]");
						$found = 1;
						last TP_SEARCH;
					}
				}
			}

			if (! $found) {
				print STDERR "Invalid execution unit $unit specified!\n";
			}
		}
	}

	# prepare the 2-dim array init
	foreach my $key (keys(%init)) {
		$ret .= "\tstatic const be_execution_unit_t *allowed_units_".$key."[] =\n";
		$ret .= "\t{\n";
		foreach (@{ $init{"$key"} }) {
			$ret .= "$_,\n";
		}
		$ret .= "\t\tNULL\n";
		$ret .= "\t};\n";
		$ret2 .= "\t\tallowed_units_$key,\n";
	}
	$ret2 .= "\t\tNULL\n";

	$ret .= "\tstatic const be_execution_unit_t **exec_units[] =\n";
	$ret .= "\t{\n";
	$ret .= $ret2;
	$ret .= "\t};\n";

	return $ret;
}

sub mangle_requirements {
	my $reqs  = shift;
	my $class = shift;
	my $flags = shift;

	my @alternatives = split(/ /, $reqs);
	for(my $idx = 0; $idx < scalar(@alternatives); $idx++) {
		$alternatives[$idx] =~ s/!/not_/g;
	}

	@alternatives = sort @alternatives;

	my $name = $class."_".join('_', @alternatives);
	if (defined($flags)) {
		$flags =~ s/\|/_/g;
		$name .= "_$flags";
	}

	return $name;
}

###
# Determines whether $name is a specified register class or not.
# @return 1 if name is register class, 0 otherwise
###
sub is_reg_class {
    my $name = shift;
    return 1 if exists($reg_classes{"$name"});
    return 0;
}

###
# Returns the register class for a given register.
# @return class or undef
###
sub get_reg_class {
    my $reg = shift;
    $reg = substr($reg, 1) if ($reg =~ /!.*/);
    return $reg2class{"$reg"}{"class"} if (exists($reg2class{"$reg"}));
    return undef;
}

###
# Returns the index of a given register within it's register class.
# @return index or undef
###
sub get_reg_index {
    my $reg = shift;
    return $reg2class{"$reg"}{"index"} if (exists($reg2class{"$reg"}));
    return undef;
}

###
# Remember the register class for each index in the given requirements.
# We need this information for requirements like "in_sX" or "out_dX"
# @return array of classes corresponding to the requirement for each index
###
sub build_inout_idx_class {
	my $n     = shift;
	my $op    = shift;
	my $is_in = shift;
	my @idx_class;

	my $inout = ($is_in ? "in" : "out");

	if (exists($n->{"reg_req"}{"$inout"})) {
		my @reqs = @{ $n->{"reg_req"}{"$inout"} };

		for (my $idx = 0; $idx <= $#reqs; $idx++) {
			my $class = undef;
			my ($req,) = split(/:/, $reqs[$idx]);

			if ($req eq "none") {
				$class = "none";
			} elsif (is_reg_class($req)) {
				$class = $req;
			} else {
				my @regs = split(/ /, $req);
GET_CLASS:		foreach my $reg (@regs) {
					if ($reg =~ /!?(in|out)\_r\d+/ || $reg =~ /!in/) {
						$class = "UNKNOWN_CLASS";
					} else {
						$class = get_reg_class($reg);
						if (!defined $class) {
							die("Fatal error: Could not get ".uc($inout)." register class for '$op' pos $idx (reg $reg) ... exiting.\n");
						} else {
							last GET_CLASS;
						} # !defined class
					} # if (reg =~ ...
				} # foreach
			} # if

			push(@idx_class, $class);
		} # for
	} # if

	return @idx_class;
}

###
# Generates the function for a given $op and a given IN-index
# which returns a subset of possible register from a register class
# @return classname from which the subset is derived or undef and
#         pos which corresponds to in/out reference position or undef
###
sub build_subset_class_func {
	my $neg           = undef;
	my $class         = undef;
	my $has_limit     = 0;
	my $limit_name;
	my $same_pos      = 0;
	my $different_pos = 0;
	my $temp;
	my @obst_init;
	my @obst_limits;
	my @obst_ignore;
	my @limit_array;
	my $limit_reqs;   #used for name mangling

	# build function header
	my $node  = shift;
	my $op    = shift;
	my $idx   = shift;
	my $is_in = shift;
	my @regs  = split(/ /, shift);
	my $flags = shift;

	my @idx_class = build_inout_idx_class($node, $op, !$is_in);

	# set/unset registers
CHECK_REQS: foreach (@regs) {
		if (!$is_in && /(!)?in_r(\d+)/) {
			my $bit_pos = 1 << ($2 - 1);
			if ($different_pos & $bit_pos) {
				if ($1) {
					print STDERR "duplicate !in constraint\n";
				} else {
					print STDERR "conflicting !in and in constraints\n";
				}
				return (undef, undef, undef, undef);
			}

			if ($same_pos & $bit_pos) {
				if ($1) {
					print STDERR "conflicting !in and in constraints\n";
				} else {
					print STDERR "duplicate in constraint\n";
				}
				return (undef, undef, undef, undef);
			}

			if ($1) {
				$different_pos |= $bit_pos;
			} else {
				$same_pos      |= $bit_pos;
			}

			$class = $idx_class[$2 - 1];
			next CHECK_REQS;
		}

		# check for negate
		if (substr($_, 0, 1) eq "!") {
			if (defined($neg) && $neg == 0) {
				# we have seen a positiv constraint as first one but this one is negative
				# this doesn't make sense
				print STDERR "Mixed positive and negative constraints for the same slot are not allowed.\n";
				return (undef, undef, undef, undef);
			}

			if (!defined($neg)) {
				$has_limit = 1;
			}

			$_   = substr($_, 1); # skip '!'
			$neg = 1;
		} else {
			if (defined($neg) && $neg == 1) {
				# we have seen a negative constraint as first one but this one is positive
				# this doesn't make sense
				print STDERR "Mixed positive and negative constraints for the same slot are not allowed.\n";
				return (undef, undef, undef, undef);
			}

			$has_limit = 1;
			$neg = 0;
		}

		# check if register belongs to one of the given classes
		$temp = get_reg_class($_);
		if (!defined($temp)) {
			print STDERR "Unknown register '$_'!\n";
			return (undef, undef, undef, undef);
		}

		# set class
		if (!defined($class)) {
			$class = $temp;
		} elsif ($class ne $temp) {
			# all registers must belong to the same class
			print STDERR "Registerclass mismatch. '$_' is not member of class '$class'.\n";
			return (undef, undef, undef, undef);
		}

		# calculate position inside the initializer bitfield (only 32 bits per
		# element)
		my $regidx = get_reg_index($_);
		my $arrayp = $regidx / 32;
		push(@{$limit_array[$arrayp]}, $_);
		$limit_reqs .= "$_ ";
	}

	# don't allow ignore regs in negative constraints
	if($neg) {
		my @cur_class = @{ $reg_classes{"$class"} };
		for (my $idx = 0; $idx <= $#cur_class; $idx++) {
			if (defined($cur_class[$idx]{"type"}) && ($cur_class[$idx]{"type"} & 4)) {
				my $reg    = $cur_class[$idx]{"name"};
				my $regix  = get_reg_index($reg);
				my $arrayp = $regix / 32;
				push(@{$limit_array[$arrayp]}, $reg);
				$limit_reqs .= "$reg ";
			}
		}
	}

	if ($has_limit == 1) {
		$limit_name = "${arch}_limit_".mangle_requirements($limit_reqs, $class);

		if(defined($limit_bitsets{$limit_name})) {
			$limit_name = $limit_bitsets{$limit_name};
			return ($class, $limit_name, $same_pos, $different_pos);
		}

		$limit_bitsets{$limit_name} = $limit_name;

		push(@obst_limit_func, "static const unsigned " . $limit_name . "[] = { ");
		my $first = 1;
		my $limitbitsetlen = $regclass2len{$class};
		my $limitarraylen = ($limitbitsetlen+31) / 32;
		for(my $i = 0; $i < $limitarraylen; $i++) {

			my $limitarraypart = $limit_array[$i];
			if($first) {
				$first = 0;
			} else {
				push(@obst_limit_func, ", ");
			}
			my $temp;
			if($neg) {
				$temp = "0xFFFFFFFF";
			}
			foreach my $reg (@{$limitarraypart}) {
				if($neg) {
					$temp .= " & ~";
				} elsif(defined($temp)) {
					$temp .= " | ";
				}
				$temp .= "BIT(REG_".uc(${reg}).")";
			}
			if(defined($temp)) {
				push(@obst_limit_func, "${temp}");
			} else {
				push(@obst_limit_func, "0");
			}
		}
		push(@obst_limit_func, " };\n");
	}

	return ($class, $limit_name, $same_pos, $different_pos);
}

###
# Generate register requirements structure
###
sub generate_requirements {
	my ($reqs, $flags) = split(/:/, shift);
	my $node  = shift;
	my $op    = shift;
	my $idx   = shift;
	my $is_in = shift;
	my $class = "";
	my $result;

	my @req_type_mask;
	if (defined($flags)) {
		foreach my $f (split(/|/, $flags)) {
			if ($f eq "I") {
				push(@req_type_mask, "arch_register_req_type_ignore");
			} elsif ($f eq "S") {
				push(@req_type_mask, "arch_register_req_type_produces_sp");
			}
		}
	}

	if ($reqs eq "none") {

		$result = <<EOF;
{
	arch_register_req_type_none,
	NULL,                         /* regclass */
	NULL,                         /* limit bitset */
	0,                            /* same pos */
	0                             /* different pos */
};

EOF
	} elsif (is_reg_class($reqs)) {
		push(@req_type_mask, "arch_register_req_type_normal");
		my $reqtype = join(" | ", @req_type_mask);
		$class  = $reqs;
		$result = <<EOF;
{
	${reqtype},
	& ${arch}_reg_classes[CLASS_${arch}_${class}],
	NULL,        /* limit bitset */
	0,           /* same pos */
	0            /* different pos */
};

EOF

	} else {
		my ($regclass, $limit_bitset, $same_pos, $different_pos)
			= build_subset_class_func($node, $op, $idx, $is_in, $reqs, $flags);

		if (!defined($regclass)) {
			die("Fatal error: Could not build subset for requirements '$reqs' of '$op' pos $idx ... exiting.\n");
		}

		if (defined($limit_bitset) && $limit_bitset ne "NULL") {
			push(@req_type_mask, "arch_register_req_type_limited");
		}
		if ($same_pos != 0) {
			push(@req_type_mask, "arch_register_req_type_should_be_same");
		}
		if ($different_pos != 0) {
			push(@req_type_mask, "arch_register_req_type_must_be_different");
		}
		my $reqtype = join(" | ", @req_type_mask);

 		if(!defined($limit_bitset)) {
			$limit_bitset = "NULL";
		}

		$class  = $regclass;
		$result = <<EOF;
{
	${reqtype},
	& ${arch}_reg_classes[CLASS_${arch}_${class}],
	${limit_bitset},
	${same_pos},        /* same pos */
	${different_pos}        /* different pos */
};

EOF
	}

	my $name = "${arch}_requirements_".mangle_requirements($reqs, $class, $flags);
	if(defined($requirements{$name})) {
		return $name;
	}
	$requirements{$name} = $name;
	push(@obst_reg_reqs, <<EOF);
static const arch_register_req_t ${name} = ${result}
EOF

	return $name;
}
