benode.c

/*
 * Copyright (C) 1995-2007 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.
 */

/**
 * @file
 * @brief       Backend node support for generic backend nodes.
 * @author      Sebastian Hack
 * @date        17.05.2005
 * @version     $Id$
 *
 * Backend node support for generic backend nodes.
 * This file provides Perm, Copy, Spill and Reload nodes.
 */
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <stdlib.h>

#include "obst.h"
#include "set.h"
#include "pmap.h"
#include "util.h"
#include "debug.h"
#include "fourcc.h"
#include "offset.h"
#include "bitfiddle.h"
#include "raw_bitset.h"

#include "irop_t.h"
#include "irmode_t.h"
#include "irnode_t.h"
#include "ircons_t.h"
#include "irprintf.h"
#include "irgwalk.h"
#include "iropt_t.h"

#include "be_t.h"
#include "belive_t.h"
#include "besched_t.h"
#include "benode_t.h"

#include "beirgmod.h"

#define OUT_POS(x) (-((x) + 1))

/* Sometimes we want to put const nodes into get_irn_generic_attr ... */
#define get_irn_attr(irn) get_irn_generic_attr((ir_node *) (irn))

static unsigned be_node_tag = FOURCC('B', 'E', 'N', 'O');

typedef struct {
	arch_register_req_t req;
	arch_irn_flags_t    flags;
} be_req_t;

typedef struct {
	const arch_register_t *reg;
	be_req_t req;
	be_req_t in_req;
} be_reg_data_t;

/** The generic be nodes attribute type. */
typedef struct {
	be_reg_data_t         *reg_data;
} be_node_attr_t;

/** The be_Return nodes attribute type. */
typedef struct {
	be_node_attr_t node_attr;
	int            num_ret_vals;  /**< number of return values */
	unsigned       pop;           /**< number of bytes that should be popped */
} be_return_attr_t;

/** The be_Stack attribute type. */
typedef struct {
	be_node_attr_t node_attr;
	int offset;           /**< The offset by which the stack shall be expanded/shrinked. */
} be_stack_attr_t;

/** The be_Frame attribute type. */
typedef struct {
	be_node_attr_t node_attr;
	ir_entity *ent;
	int offset;
} be_frame_attr_t;

/** The be_Call attribute type. */
typedef struct {
	be_node_attr_t node_attr;
	ir_entity *ent;      /**< The called entity if this is a static call. */
	ir_type *call_tp;    /**< The call type, copied from the original Call node. */
} be_call_attr_t;

typedef struct {
	be_node_attr_t node_attr;
	ir_entity **in_entities;
	ir_entity **out_entities;
} be_memperm_attr_t;

ir_op *op_be_Spill;
ir_op *op_be_Reload;
ir_op *op_be_Perm;
ir_op *op_be_MemPerm;
ir_op *op_be_Copy;
ir_op *op_be_Keep;
ir_op *op_be_CopyKeep;
ir_op *op_be_Call;
ir_op *op_be_Return;
ir_op *op_be_IncSP;
ir_op *op_be_AddSP;
ir_op *op_be_SubSP;
ir_op *op_be_RegParams;
ir_op *op_be_FrameAddr;
ir_op *op_be_Barrier;

static int beo_base = -1;

static const ir_op_ops be_node_op_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


/**
 * Compare two node attributes.
 *
 * @return zero if both attributes are identically
 */
static int _node_cmp_attr(be_node_attr_t *a, be_node_attr_t *b) {
	int i, len;

	if(ARR_LEN(a->reg_data) != ARR_LEN(b->reg_data))
		return 1;

	len = ARR_LEN(a->reg_data);
	for (i = 0; i < len; ++i) {
		if (a->reg_data[i].reg != b->reg_data[i].reg ||
				memcmp(&a->reg_data[i].in_req, &b->reg_data[i].in_req, sizeof(b->reg_data[i].in_req)) ||
			    memcmp(&a->reg_data[i].req,    &b->reg_data[i].req,    sizeof(a->reg_data[i].req)))
			return 1;
	}

	return 0;
}

static int node_cmp_attr(ir_node *a, ir_node *b) {
	be_node_attr_t *a_attr = get_irn_attr(a);
	be_node_attr_t *b_attr = get_irn_attr(b);

	return _node_cmp_attr(a_attr, b_attr);
}

/**
 * Compare the attributes of two FrameAddr nodes.
 *
 * @return zero if both attributes are identically
 */
static int FrameAddr_cmp_attr(ir_node *a, ir_node *b) {
	be_frame_attr_t *a_attr = get_irn_attr(a);
	be_frame_attr_t *b_attr = get_irn_attr(b);

	if (a_attr->ent != b_attr->ent || a_attr->offset != b_attr->offset)
		return 1;

	return _node_cmp_attr((be_node_attr_t*) a_attr, (be_node_attr_t*) b_attr);
}

static int Return_cmp_attr(ir_node *a, ir_node *b) {
	be_return_attr_t *a_attr = get_irn_attr(a);
	be_return_attr_t *b_attr = get_irn_attr(b);

	if (a_attr->num_ret_vals != b_attr->num_ret_vals)
		return 1;
	if (a_attr->pop != b_attr->pop)
		return 1;

	return _node_cmp_attr((be_node_attr_t*) a_attr, (be_node_attr_t*) b_attr);
}

static int Stack_cmp_attr(ir_node *a, ir_node *b) {
	be_stack_attr_t *a_attr = get_irn_attr(a);
	be_stack_attr_t *b_attr = get_irn_attr(b);

	if (a_attr->offset != b_attr->offset)
		return 1;

	return _node_cmp_attr((be_node_attr_t*) a_attr, (be_node_attr_t*) b_attr);
}

static int Call_cmp_attr(ir_node *a, ir_node *b) {
	be_call_attr_t *a_attr = get_irn_attr(a);
	be_call_attr_t *b_attr = get_irn_attr(b);

	if (a_attr->ent != b_attr->ent ||
			a_attr->call_tp != b_attr->call_tp)
		return 1;

	return _node_cmp_attr((be_node_attr_t*) a_attr, (be_node_attr_t*) b_attr);
}

static INLINE be_req_t *get_be_req(const ir_node *node, int pos)
{
	int idx;
	be_node_attr_t *attr;
	be_reg_data_t *rd;

	assert(is_be_node(node));
	attr = get_irn_attr(node);

	if(pos < 0) {
		idx = -(pos + 1);
	} else {
		idx = pos;
		assert(idx < get_irn_arity(node));
	}
	assert(idx < ARR_LEN(attr->reg_data));
	rd = &attr->reg_data[idx];

	return pos < 0 ? &rd->req : &rd->in_req;
}

static INLINE arch_register_req_t *get_req(const ir_node *node, int pos)
{
	be_req_t *bereq = get_be_req(node, pos);
	return &bereq->req;
}

void be_node_init(void) {
	static int inited = 0;

	if(inited)
		return;

	inited = 1;

	/* Acquire all needed opcodes. */
	beo_base = get_next_ir_opcodes(beo_Last);

	op_be_Spill      = new_ir_op(beo_base + beo_Spill,      "be_Spill",      op_pin_state_pinned,     N, oparity_unary,    0, sizeof(be_frame_attr_t),   &be_node_op_ops);
	op_be_Reload     = new_ir_op(beo_base + beo_Reload,     "be_Reload",     op_pin_state_pinned,     N, oparity_zero,     0, sizeof(be_frame_attr_t),   &be_node_op_ops);
	op_be_Perm       = new_ir_op(beo_base + beo_Perm,       "be_Perm",       op_pin_state_pinned,     N, oparity_variable, 0, sizeof(be_node_attr_t),    &be_node_op_ops);
	op_be_MemPerm    = new_ir_op(beo_base + beo_MemPerm,    "be_MemPerm",    op_pin_state_pinned,     N, oparity_variable, 0, sizeof(be_memperm_attr_t), &be_node_op_ops);
	op_be_Copy       = new_ir_op(beo_base + beo_Copy,       "be_Copy",       op_pin_state_floats,     N, oparity_unary,    0, sizeof(be_node_attr_t),    &be_node_op_ops);
	op_be_Keep       = new_ir_op(beo_base + beo_Keep,       "be_Keep",       op_pin_state_pinned,     K, oparity_dynamic,  0, sizeof(be_node_attr_t),    &be_node_op_ops);
	op_be_CopyKeep   = new_ir_op(beo_base + beo_CopyKeep,   "be_CopyKeep",   op_pin_state_pinned,     K, oparity_variable, 0, sizeof(be_node_attr_t),    &be_node_op_ops);
	op_be_Call       = new_ir_op(beo_base + beo_Call,       "be_Call",       op_pin_state_pinned,     F, oparity_variable, 0, sizeof(be_call_attr_t),    &be_node_op_ops);
	op_be_Return     = new_ir_op(beo_base + beo_Return,     "be_Return",     op_pin_state_pinned,     X, oparity_dynamic,  0, sizeof(be_return_attr_t),  &be_node_op_ops);
	op_be_AddSP      = new_ir_op(beo_base + beo_AddSP,      "be_AddSP",      op_pin_state_pinned,     N, oparity_unary,    0, sizeof(be_node_attr_t),    &be_node_op_ops);
	op_be_SubSP      = new_ir_op(beo_base + beo_SubSP,      "be_SubSP",      op_pin_state_pinned,     N, oparity_unary,    0, sizeof(be_node_attr_t),    &be_node_op_ops);
	op_be_IncSP      = new_ir_op(beo_base + beo_IncSP,      "be_IncSP",      op_pin_state_pinned,     N, oparity_unary,    0, sizeof(be_stack_attr_t),   &be_node_op_ops);
	op_be_RegParams  = new_ir_op(beo_base + beo_RegParams,  "be_RegParams",  op_pin_state_pinned,     N, oparity_zero,     0, sizeof(be_node_attr_t),    &be_node_op_ops);
	op_be_FrameAddr  = new_ir_op(beo_base + beo_FrameAddr,  "be_FrameAddr",  op_pin_state_floats,     N, oparity_unary,    0, sizeof(be_frame_attr_t),   &be_node_op_ops);
	op_be_Barrier    = new_ir_op(beo_base + beo_Barrier,    "be_Barrier",    op_pin_state_pinned,     N, oparity_dynamic,  0, sizeof(be_node_attr_t),    &be_node_op_ops);

	set_op_tag(op_be_Spill,      &be_node_tag);
	op_be_Spill->ops.node_cmp_attr = FrameAddr_cmp_attr;
	set_op_tag(op_be_Reload,     &be_node_tag);
	op_be_Reload->ops.node_cmp_attr = FrameAddr_cmp_attr;
	set_op_tag(op_be_Perm,       &be_node_tag);
	op_be_Perm->ops.node_cmp_attr = node_cmp_attr;
	set_op_tag(op_be_MemPerm,    &be_node_tag);
	op_be_MemPerm->ops.node_cmp_attr = node_cmp_attr;
	set_op_tag(op_be_Copy,       &be_node_tag);
	op_be_Copy->ops.node_cmp_attr = node_cmp_attr;
	set_op_tag(op_be_Keep,       &be_node_tag);
	op_be_Keep->ops.node_cmp_attr = node_cmp_attr;
	set_op_tag(op_be_CopyKeep,   &be_node_tag);
	op_be_CopyKeep->ops.node_cmp_attr = node_cmp_attr;
	set_op_tag(op_be_Call,       &be_node_tag);
	op_be_Call->ops.node_cmp_attr = Call_cmp_attr;
	set_op_tag(op_be_Return,     &be_node_tag);
	op_be_Return->ops.node_cmp_attr = Return_cmp_attr;
	set_op_tag(op_be_AddSP,      &be_node_tag);
	op_be_AddSP->ops.node_cmp_attr = node_cmp_attr;
	set_op_tag(op_be_SubSP,      &be_node_tag);
	op_be_SubSP->ops.node_cmp_attr = node_cmp_attr;
	set_op_tag(op_be_IncSP,      &be_node_tag);
	op_be_IncSP->ops.node_cmp_attr = Stack_cmp_attr;
	set_op_tag(op_be_RegParams,  &be_node_tag);
	op_be_RegParams->ops.node_cmp_attr = node_cmp_attr;
	set_op_tag(op_be_FrameAddr,  &be_node_tag);
	op_be_FrameAddr->ops.node_cmp_attr = FrameAddr_cmp_attr;
	set_op_tag(op_be_Barrier,    &be_node_tag);
	op_be_Barrier->ops.node_cmp_attr = node_cmp_attr;
}

/**
 * Initializes the generic attribute of all be nodes and return ir.
 */
static void *init_node_attr(ir_node *node, int max_reg_data)
{
	ir_graph *irg = get_irn_irg(node);
	struct obstack *obst = get_irg_obstack(irg);
	be_node_attr_t *a = get_irn_attr(node);

	memset(a, 0, sizeof(get_op_attr_size(get_irn_op(node))));

	if(max_reg_data >= 0) {
		a->reg_data = NEW_ARR_D(be_reg_data_t, obst, max_reg_data);
		memset(a->reg_data, 0, max_reg_data * sizeof(a->reg_data[0]));
	} else {
		a->reg_data = NEW_ARR_F(be_reg_data_t, 0);
	}

	return a;
}

static void add_register_req(ir_node *node)
{
	be_node_attr_t *a = get_irn_attr(node);
	be_reg_data_t regreq;
	memset(&regreq, 0, sizeof(regreq));
	ARR_APP1(be_reg_data_t, a->reg_data, regreq);
}

int is_be_node(const ir_node *irn)
{
	return get_op_tag(get_irn_op(irn)) == &be_node_tag;
}

be_opcode_t be_get_irn_opcode(const ir_node *irn)
{
	return is_be_node(irn) ? (be_opcode_t) get_irn_opcode(irn) - beo_base : beo_NoBeOp;
}

/**
 * Skip Proj nodes and return their Proj numbers.
 *
 * If *node is a Proj or Proj(Proj) node, skip it.
 *
 * @param node  points to the node to be skipped
 *
 * @return 0 if *node was no Proj node, its Proj number else.
 */
static int redir_proj(const ir_node **node)
{
	const ir_node *n = *node;

	if(is_Proj(n)) {
		ir_node *irn;

		*node = irn = get_Proj_pred(n);
		if(is_Proj(irn)) {
			assert(get_irn_mode(irn) == mode_T);
			*node = get_Proj_pred(irn);
		}
		return get_Proj_proj(n);
	}

	return 0;
}

static be_reg_data_t *retrieve_reg_data(const ir_node *node)
{
	be_node_attr_t *attr;
	int pos = 0;

	if(is_Proj(node)) {
		pos = get_Proj_proj(node);
		node = get_Proj_pred(node);
	}

	assert(is_be_node(node));
	attr = get_irn_attr(node);
	assert(pos >= 0 && pos < ARR_LEN(attr->reg_data) && "illegal proj number");

	return &attr->reg_data[pos];
}

static void
be_node_set_irn_reg(const void *self, ir_node *irn, const arch_register_t *reg)
{
	be_reg_data_t *r = retrieve_reg_data(irn);
	(void) self;
	r->reg = reg;
}

ir_node *be_new_Spill(const arch_register_class_t *cls, const arch_register_class_t *cls_frame,
	ir_graph *irg, ir_node *bl, ir_node *frame, ir_node *to_spill)
{
	be_frame_attr_t *a;
	ir_node         *in[2];
	ir_node         *res;

	in[0]     = frame;
	in[1]     = to_spill;
	res       = new_ir_node(NULL, irg, bl, op_be_Spill, mode_M, 2, in);
	a         = init_node_attr(res, 2);
	a->ent    = NULL;
	a->offset = 0;

	be_node_set_reg_class(res, be_pos_Spill_frame, cls_frame);
	be_node_set_reg_class(res, be_pos_Spill_val, cls);
	return res;
}

ir_node *be_new_Reload(const arch_register_class_t *cls, const arch_register_class_t *cls_frame,
	ir_graph *irg, ir_node *bl, ir_node *frame, ir_node *mem, ir_mode *mode)
{
	ir_node *in[2];
	ir_node *res;

	in[0] = frame;
	in[1] = mem;
	res   = new_ir_node(NULL, irg, bl, op_be_Reload, mode, 2, in);

	init_node_attr(res, 2);
	be_node_set_reg_class(res, -1, cls);
	be_node_set_reg_class(res, be_pos_Reload_frame, cls_frame);
	be_node_set_flags(res, -1, arch_irn_flags_rematerializable);
	return res;
}

ir_node *be_get_Reload_mem(const ir_node *irn)
{
	assert(be_is_Reload(irn));
	return get_irn_n(irn, be_pos_Reload_mem);
}

ir_node *be_get_Reload_frame(const ir_node *irn)
{
	assert(be_is_Reload(irn));
	return get_irn_n(irn, be_pos_Reload_frame);
}

ir_node *be_get_Spill_val(const ir_node *irn)
{
	assert(be_is_Spill(irn));
	return get_irn_n(irn, be_pos_Spill_val);
}

ir_node *be_get_Spill_frame(const ir_node *irn)
{
	assert(be_is_Spill(irn));
	return get_irn_n(irn, be_pos_Spill_frame);
}

ir_node *be_new_Perm(const arch_register_class_t *cls, ir_graph *irg, ir_node *bl, int n, ir_node *in[])
{
	int i;
	ir_node *irn = new_ir_node(NULL, irg, bl, op_be_Perm, mode_T, n, in);
	init_node_attr(irn, n);
	for(i = 0; i < n; ++i) {
		be_node_set_reg_class(irn, i, cls);
		be_node_set_reg_class(irn, OUT_POS(i), cls);
	}

	return irn;
}

void be_Perm_reduce(ir_node *perm, int new_size, int *map)
{
	ir_graph *irg           = get_irn_irg(perm);
	int            arity    = get_irn_arity(perm);
	be_reg_data_t *old_data = alloca(arity * sizeof(old_data[0]));
	be_node_attr_t *attr    = get_irn_attr(perm);
	ir_node **new_in        = NEW_ARR_D(ir_node *, irg->obst, new_size);

	int i;

	assert(be_is_Perm(perm));
	assert(new_size <= arity);

	/* save the old register data */
	memcpy(old_data, attr->reg_data, arity * sizeof(old_data[0]));

	/* compose the new in array and set the new register data directly in place */
	for (i = 0; i < new_size; ++i) {
		int idx = map[i];
		new_in[i]         = get_irn_n(perm, idx);
		attr->reg_data[i] = old_data[idx];
	}

	set_irn_in(perm, new_size, new_in);
}

ir_node *be_new_MemPerm(const arch_env_t *arch_env, ir_graph *irg, ir_node *bl, int n, ir_node *in[])
{
	int i;
	ir_node *frame = get_irg_frame(irg);
	const arch_register_class_t *cls_frame = arch_get_irn_reg_class(arch_env, frame, -1);
	ir_node *irn;
	const arch_register_t *sp = arch_env->isa->sp;
	be_memperm_attr_t *attr;
	ir_node **real_in;

	real_in = alloca((n+1) * sizeof(real_in[0]));
	real_in[0] = frame;
	memcpy(&real_in[1], in, n * sizeof(real_in[0]));

	irn =  new_ir_node(NULL, irg, bl, op_be_MemPerm, mode_T, n+1, real_in);

	init_node_attr(irn, n + 1);
	be_node_set_reg_class(irn, 0, sp->reg_class);
	for(i = 0; i < n; ++i) {
		be_node_set_reg_class(irn, i + 1, cls_frame);
		be_node_set_reg_class(irn, OUT_POS(i), cls_frame);
	}

	attr = get_irn_attr(irn);

	attr->in_entities = obstack_alloc(irg->obst, n * sizeof(attr->in_entities[0]));
	memset(attr->in_entities, 0, n * sizeof(attr->in_entities[0]));
	attr->out_entities = obstack_alloc(irg->obst, n*sizeof(attr->out_entities[0]));
	memset(attr->out_entities, 0, n*sizeof(attr->out_entities[0]));

	return irn;
}


ir_node *be_new_Copy(const arch_register_class_t *cls, ir_graph *irg, ir_node *bl, ir_node *op)
{
	ir_node *in[1];
	ir_node *res;
	arch_register_req_t *req;

	in[0] = op;
	res   = new_ir_node(NULL, irg, bl, op_be_Copy, get_irn_mode(op), 1, in);
	init_node_attr(res, 1);
	be_node_set_reg_class(res, 0, cls);
	be_node_set_reg_class(res, OUT_POS(0), cls);

	req = get_req(res, OUT_POS(0));
	req->cls = cls;
	req->type = arch_register_req_type_should_be_same;
	req->other_same[0] =  0;
	req->other_same[1] = -1;

	return res;
}

ir_node *be_get_Copy_op(const ir_node *cpy) {
	return get_irn_n(cpy, be_pos_Copy_op);
}

void be_set_Copy_op(ir_node *cpy, ir_node *op) {
	set_irn_n(cpy, be_pos_Copy_op, op);
}

ir_node *be_new_Keep(const arch_register_class_t *cls, ir_graph *irg, ir_node *bl, int n, ir_node *in[])
{
	int i;
	ir_node *res;

	res = new_ir_node(NULL, irg, bl, op_be_Keep, mode_ANY, -1, NULL);
	init_node_attr(res, -1);

	for(i = 0; i < n; ++i) {
		add_irn_n(res, in[i]);
		add_register_req(res);
		be_node_set_reg_class(res, i, cls);
	}
	keep_alive(res);

	return res;
}

void be_Keep_add_node(ir_node *keep, const arch_register_class_t *cls, ir_node *node)
{
	int n;

	assert(be_is_Keep(keep));
	n = add_irn_n(keep, node);
	add_register_req(keep);
	be_node_set_reg_class(keep, n, cls);
}

/* creates a be_Call */
ir_node *be_new_Call(dbg_info *dbg, ir_graph *irg, ir_node *bl, ir_node *mem, ir_node *sp, ir_node *ptr,
                     int n_outs, int n, ir_node *in[], ir_type *call_tp)
{
	be_call_attr_t *a;
	int real_n = be_pos_Call_first_arg + n;
	ir_node *irn;
	ir_node **real_in;

	NEW_ARR_A(ir_node *, real_in, real_n);
	real_in[be_pos_Call_mem] = mem;
	real_in[be_pos_Call_sp]  = sp;
	real_in[be_pos_Call_ptr] = ptr;
	memcpy(&real_in[be_pos_Call_first_arg], in, n * sizeof(in[0]));

	irn = new_ir_node(dbg, irg, bl, op_be_Call, mode_T, real_n, real_in);
	a = init_node_attr(irn, (n_outs > real_n ? n_outs : real_n));
	a->ent     = NULL;
	a->call_tp = call_tp;
	return irn;
}

/* Gets the call entity or NULL if this is no static call. */
ir_entity *be_Call_get_entity(const ir_node *call) {
	be_call_attr_t *a = get_irn_attr(call);
	assert(be_is_Call(call));
	return a->ent;
}

/* Sets the call entity. */
void be_Call_set_entity(ir_node *call, ir_entity *ent) {
	be_call_attr_t *a = get_irn_attr(call);
	assert(be_is_Call(call));
	a->ent = ent;
}

/* Gets the call type. */
ir_type *be_Call_get_type(ir_node *call) {
	be_call_attr_t *a = get_irn_attr(call);
	assert(be_is_Call(call));
	return a->call_tp;
}

/* Sets the call type. */
void be_Call_set_type(ir_node *call, ir_type *call_tp) {
	be_call_attr_t *a = get_irn_attr(call);
	assert(be_is_Call(call));
	a->call_tp = call_tp;
}

/* Construct a new be_Return. */
ir_node *be_new_Return(dbg_info *dbg, ir_graph *irg, ir_node *block, int n_res,
                       unsigned pop, int n, ir_node *in[])
{
	be_return_attr_t *a;
	ir_node *res;
	int i;

	res = new_ir_node(dbg, irg, block, op_be_Return, mode_X, -1, NULL);
	init_node_attr(res, -1);
	for(i = 0; i < n; ++i) {
		add_irn_n(res, in[i]);
		add_register_req(res);
	}

	a = get_irn_attr(res);
	a->num_ret_vals = n_res;
	a->pop          = pop;

	return res;
}

/* Returns the number of real returns values */
int be_Return_get_n_rets(const ir_node *ret)
{
	const be_return_attr_t *a = get_irn_generic_attr_const(ret);
	return a->num_ret_vals;
}

unsigned be_Return_get_pop(const ir_node *ret)
{
	const be_return_attr_t *a = get_irn_generic_attr_const(ret);
	return a->pop;
}

int be_Return_append_node(ir_node *ret, ir_node *node)
{
	int pos;

	pos = add_irn_n(ret, node);
	add_register_req(ret);

	return pos;
}

ir_node *be_new_IncSP(const arch_register_t *sp, ir_graph *irg, ir_node *bl, ir_node *old_sp, int offset)
{
	be_stack_attr_t *a;
	ir_node *irn;
	ir_node *in[1];

	in[0]     = old_sp;
	irn       = new_ir_node(NULL, irg, bl, op_be_IncSP, sp->reg_class->mode, sizeof(in) / sizeof(in[0]), in);
	a         = init_node_attr(irn, 1);
	a->offset = offset;

	be_node_set_flags(irn, -1, arch_irn_flags_ignore | arch_irn_flags_modify_sp);

	/* Set output constraint to stack register. */
	be_node_set_reg_class(irn, 0, sp->reg_class);
	be_set_constr_single_reg(irn, BE_OUT_POS(0), sp);
	be_node_set_irn_reg(NULL, irn, sp);

	return irn;
}

ir_node *be_new_AddSP(const arch_register_t *sp, ir_graph *irg, ir_node *bl, ir_node *old_sp, ir_node *sz)
{
	be_node_attr_t *a;
	ir_node *irn;
	ir_node *in[be_pos_AddSP_last];
	const arch_register_class_t *class;

	in[be_pos_AddSP_old_sp] = old_sp;
	in[be_pos_AddSP_size]   = sz;

	irn = new_ir_node(NULL, irg, bl, op_be_AddSP, mode_T, be_pos_AddSP_last, in);
	a   = init_node_attr(irn, be_pos_AddSP_last);

	be_node_set_flags(irn, OUT_POS(pn_be_AddSP_sp),
	                  arch_irn_flags_ignore | arch_irn_flags_modify_sp);

	/* Set output constraint to stack register. */
	be_set_constr_single_reg(irn, be_pos_AddSP_old_sp, sp);
	be_node_set_reg_class(irn, be_pos_AddSP_size, arch_register_get_class(sp));
	be_set_constr_single_reg(irn, OUT_POS(pn_be_AddSP_sp), sp);
	a->reg_data[pn_be_AddSP_sp].reg = sp;

	class = arch_register_get_class(sp);
	be_node_set_reg_class(irn, OUT_POS(pn_be_AddSP_res), class);

	return irn;
}

ir_node *be_new_SubSP(const arch_register_t *sp, ir_graph *irg, ir_node *bl, ir_node *old_sp, ir_node *sz)
{
	be_node_attr_t *a;
	ir_node *irn;
	ir_node *in[be_pos_SubSP_last];

	in[be_pos_SubSP_old_sp] = old_sp;
	in[be_pos_SubSP_size]   = sz;

	irn = new_ir_node(NULL, irg, bl, op_be_SubSP, mode_T, be_pos_SubSP_last, in);
	a   = init_node_attr(irn, be_pos_SubSP_last);

	be_node_set_flags(irn, OUT_POS(pn_be_SubSP_sp),
	                  arch_irn_flags_ignore | arch_irn_flags_modify_sp);

	/* Set output constraint to stack register. */
	be_set_constr_single_reg(irn, be_pos_SubSP_old_sp, sp);
	be_node_set_reg_class(irn, be_pos_SubSP_size, arch_register_get_class(sp));
	be_set_constr_single_reg(irn, OUT_POS(pn_be_SubSP_sp), sp);
	a->reg_data[pn_be_SubSP_sp].reg = sp;

	return irn;
}

ir_node *be_new_RegParams(ir_graph *irg, ir_node *bl, int n_outs)
{
	ir_node *res;
	int i;

	res = new_ir_node(NULL, irg, bl, op_be_RegParams, mode_T, 0, NULL);
	init_node_attr(res, -1);
	for(i = 0; i < n_outs; ++i)
		add_register_req(res);

	return res;
}

ir_node *be_RegParams_append_out_reg(ir_node *regparams,
                                     const arch_env_t *arch_env,
                                     const arch_register_t *reg)
{
	ir_graph *irg = get_irn_irg(regparams);
	ir_node *block = get_nodes_block(regparams);
	be_node_attr_t *attr = get_irn_attr(regparams);
	const arch_register_class_t *cls = arch_register_get_class(reg);
	ir_mode *mode = arch_register_class_mode(cls);
	int n = ARR_LEN(attr->reg_data);
	ir_node *proj;

	assert(be_is_RegParams(regparams));
	proj = new_r_Proj(irg, block, regparams, mode, n);
	add_register_req(regparams);
	be_set_constr_single_reg(regparams, BE_OUT_POS(n), reg);
	arch_set_irn_register(arch_env, proj, reg);

	/* TODO decide, whether we need to set ignore/modify sp flags here? */

	return proj;
}

ir_node *be_new_FrameAddr(const arch_register_class_t *cls_frame, ir_graph *irg, ir_node *bl, ir_node *frame, ir_entity *ent)
{
	be_frame_attr_t *a;
	ir_node *irn;
	ir_node *in[1];

	in[0]  = frame;
	irn    = new_ir_node(NULL, irg, bl, op_be_FrameAddr, get_irn_mode(frame), 1, in);
	a      = init_node_attr(irn, 1);
	a->ent = ent;
	a->offset = 0;
	be_node_set_reg_class(irn, 0, cls_frame);
	be_node_set_reg_class(irn, OUT_POS(0), cls_frame);

	return optimize_node(irn);
}

ir_node *be_get_FrameAddr_frame(const ir_node *node) {
	assert(be_is_FrameAddr(node));
	return get_irn_n(node, be_pos_FrameAddr_ptr);
}

ir_entity *be_get_FrameAddr_entity(const ir_node *node)
{
	const be_frame_attr_t *attr = get_irn_generic_attr_const(node);
	return attr->ent;
}

ir_node *be_new_CopyKeep(const arch_register_class_t *cls, ir_graph *irg, ir_node *bl, ir_node *src, int n, ir_node *in_keep[], ir_mode *mode)
{
	ir_node *irn;
	ir_node **in = (ir_node **) alloca((n + 1) * sizeof(in[0]));

	in[0] = src;
	memcpy(&in[1], in_keep, n * sizeof(in[0]));
	irn   = new_ir_node(NULL, irg, bl, op_be_CopyKeep, mode, n + 1, in);
	init_node_attr(irn, n + 1);
	be_node_set_reg_class(irn, OUT_POS(0), cls);
	be_node_set_reg_class(irn, 0, cls);

	return irn;
}

ir_node *be_new_CopyKeep_single(const arch_register_class_t *cls, ir_graph *irg, ir_node *bl, ir_node *src, ir_node *keep, ir_mode *mode)
{
	ir_node *in[1];

	in[0] = keep;
	return be_new_CopyKeep(cls, irg, bl, src, 1, in, mode);
}

ir_node *be_get_CopyKeep_op(const ir_node *cpy) {
	return get_irn_n(cpy, be_pos_CopyKeep_op);
}

void be_set_CopyKeep_op(ir_node *cpy, ir_node *op) {
	set_irn_n(cpy, be_pos_CopyKeep_op, op);
}

ir_node *be_new_Barrier(ir_graph *irg, ir_node *bl, int n, ir_node *in[])
{
	ir_node *res;
	int i;

	res = new_ir_node(NULL, irg, bl, op_be_Barrier, mode_T, -1, NULL);
	init_node_attr(res, -1);
	for(i = 0; i < n; ++i) {
		add_irn_n(res, in[i]);
		add_register_req(res);
	}

	return res;
}

ir_node *be_Barrier_append_node(ir_node *barrier, ir_node *node)
{
	ir_graph *irg = get_irn_irg(barrier);
	ir_node *block = get_nodes_block(barrier);
	ir_mode *mode = get_irn_mode(node);
	int n = add_irn_n(barrier, node);

	ir_node *proj = new_r_Proj(irg, block, barrier, mode, n);
	add_register_req(barrier);

	return proj;
}

int be_is_Spill         (const ir_node *irn) { return be_get_irn_opcode(irn) == beo_Spill          ; }
int be_is_Reload        (const ir_node *irn) { return be_get_irn_opcode(irn) == beo_Reload         ; }
int be_is_Copy          (const ir_node *irn) { return be_get_irn_opcode(irn) == beo_Copy           ; }
int be_is_CopyKeep      (const ir_node *irn) { return be_get_irn_opcode(irn) == beo_CopyKeep       ; }
int be_is_Perm          (const ir_node *irn) { return be_get_irn_opcode(irn) == beo_Perm           ; }
int be_is_MemPerm       (const ir_node *irn) { return be_get_irn_opcode(irn) == beo_MemPerm        ; }
int be_is_Keep          (const ir_node *irn) { return be_get_irn_opcode(irn) == beo_Keep           ; }
int be_is_Call          (const ir_node *irn) { return be_get_irn_opcode(irn) == beo_Call           ; }
int be_is_Return        (const ir_node *irn) { return be_get_irn_opcode(irn) == beo_Return         ; }
int be_is_IncSP         (const ir_node *irn) { return be_get_irn_opcode(irn) == beo_IncSP          ; }
int be_is_AddSP         (const ir_node *irn) { return be_get_irn_opcode(irn) == beo_AddSP          ; }
int be_is_SubSP         (const ir_node *irn) { return be_get_irn_opcode(irn) == beo_SubSP          ; }
int be_is_RegParams     (const ir_node *irn) { return be_get_irn_opcode(irn) == beo_RegParams      ; }
int be_is_FrameAddr     (const ir_node *irn) { return be_get_irn_opcode(irn) == beo_FrameAddr      ; }
int be_is_Barrier       (const ir_node *irn) { return be_get_irn_opcode(irn) == beo_Barrier        ; }

int be_has_frame_entity(const ir_node *irn)
{
	switch(be_get_irn_opcode(irn)) {
	case beo_Spill:
	case beo_Reload:
	case beo_FrameAddr:
		return 1;
	default:
		return 0;
	}
}

ir_entity *be_get_frame_entity(const ir_node *irn)
{
	if (be_has_frame_entity(irn)) {
		be_frame_attr_t *a = get_irn_attr(irn);
		return a->ent;
	}
	return NULL;
}

int be_get_frame_offset(const ir_node *irn)
{
	assert(is_be_node(irn));
	if (be_has_frame_entity(irn)) {
		be_frame_attr_t *a = get_irn_attr(irn);
		return a->offset;
	}
	return 0;
}

void be_set_MemPerm_in_entity(const ir_node *irn, int n, ir_entity *ent)
{
	be_memperm_attr_t *attr = get_irn_attr(irn);

	assert(be_is_MemPerm(irn));
	assert(n < be_get_MemPerm_entity_arity(irn));

	attr->in_entities[n] = ent;
}

ir_entity* be_get_MemPerm_in_entity(const ir_node* irn, int n)
{
	be_memperm_attr_t *attr = get_irn_attr(irn);

	assert(be_is_MemPerm(irn));
	assert(n < be_get_MemPerm_entity_arity(irn));

	return attr->in_entities[n];
}

void be_set_MemPerm_out_entity(const ir_node *irn, int n, ir_entity *ent)
{
	be_memperm_attr_t *attr = get_irn_attr(irn);

	assert(be_is_MemPerm(irn));
	assert(n < be_get_MemPerm_entity_arity(irn));

	attr->out_entities[n] = ent;
}