Get rid of be_SetSP.

[libfirm] / ir / be / 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 */
} 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;

        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;

        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,
                       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;

        return res;
}

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

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;
}

ir_entity* be_get_MemPerm_out_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->out_entities[n];
}

int be_get_MemPerm_entity_arity(const ir_node *irn)
{
        return get_irn_arity(irn) - 1;
}

void be_set_constr_single_reg(ir_node *node, int pos, const arch_register_t *reg)
{
        arch_register_req_t *req = get_req(node, pos);
        const arch_register_class_t *cls = arch_register_get_class(reg);
        ir_graph *irg = get_irn_irg(node);
        struct obstack *obst = get_irg_obstack(irg);
        unsigned *limited_bitset;

        assert(req->cls == NULL || req->cls == cls);
        assert(! (req->type & arch_register_req_type_limited));
        assert(req->limited == NULL);

        limited_bitset = rbitset_obstack_alloc(obst, arch_register_class_n_regs(cls));
        rbitset_set(limited_bitset, arch_register_get_index(reg));

        req->cls = cls;
        req->type |= arch_register_req_type_limited;
        req->limited = limited_bitset;
}

void be_set_constr_limited(ir_node *node, int pos, const arch_register_req_t *req)
{
        ir_graph *irg = get_irn_irg(node);
        struct obstack *obst = get_irg_obstack(irg);
        arch_register_req_t *r = get_req(node, pos);

        assert(arch_register_req_is(req, limited));
        assert(! (req->type & (arch_register_req_type_should_be_same | arch_register_req_type_should_be_different)));
        memcpy(r, req, sizeof(r[0]));
        r->limited = rbitset_duplicate_obstack_alloc(obst, req->limited, req->cls->n_regs);
}

void be_node_set_flags(ir_node *irn, int pos, arch_irn_flags_t flags)
{
        be_req_t *bereq = get_be_req(irn, pos);
        bereq->flags = flags;
}

void be_node_set_reg_class(ir_node *irn, int pos, const arch_register_class_t *cls)
{
        arch_register_req_t *req = get_req(irn, pos);

        req->cls = cls;

        if (cls == NULL) {
                req->type = arch_register_req_type_none;
        } else if (req->type == arch_register_req_type_none) {
                req->type = arch_register_req_type_normal;
        }
}

void be_node_set_req_type(ir_node *irn, int pos, arch_register_req_type_t type)
{
        arch_register_req_t *req = get_req(irn, pos);
        req->type = type;
}

ir_node *be_get_IncSP_pred(ir_node *irn) {
        assert(be_is_IncSP(irn));
        return get_irn_n(irn, 0);
}

void be_set_IncSP_pred(ir_node *incsp, ir_node *pred) {
        assert(be_is_IncSP(incsp));
        set_irn_n(incsp, 0, pred);
}

void be_set_IncSP_offset(ir_node *irn, int offset)
{
        be_stack_attr_t *a = get_irn_attr(irn);
        assert(be_is_IncSP(irn));
        a->offset = offset;
}

int be_get_IncSP_offset(const ir_node *irn)
{
        be_stack_attr_t *a = get_irn_attr(irn);
        assert(be_is_IncSP(irn));
        return a->offset;
}

ir_node *be_spill(const arch_env_t *arch_env, ir_node *irn)
{
        ir_node                     *bl        = get_nodes_block(irn);
        ir_graph                    *irg       = get_irn_irg(bl);
        ir_node                     *frame     = get_irg_frame(irg);
        const arch_register_class_t *cls       = arch_get_irn_reg_class(arch_env, irn, -1);
        const arch_register_class_t *cls_frame = arch_get_irn_reg_class(arch_env, frame, -1);
        ir_node                     *spill;

        spill = be_new_Spill(cls, cls_frame, irg, bl, frame, irn);
        return spill;
}

ir_node *be_reload(const arch_env_t *arch_env, const arch_register_class_t *cls, ir_node *insert, ir_mode *mode, ir_node *spill)
{
        ir_node  *reload;
        ir_node  *bl    = is_Block(insert) ? insert : get_nodes_block(insert);
        ir_graph *irg   = get_irn_irg(bl);
        ir_node  *frame = get_irg_frame(irg);
        const arch_register_class_t *cls_frame = arch_get_irn_reg_class(arch_env, frame, -1);

        assert(be_is_Spill(spill) || (is_Phi(spill) && get_irn_mode(spill) == mode_M));

        reload = be_new_Reload(cls, cls_frame, irg, bl, frame, spill, mode);

        if (is_Block(insert)) {
                insert = sched_skip(insert, 0, sched_skip_cf_predicator, (void *) arch_env);
                sched_add_after(insert, reload);
        } else {
                sched_add_before(insert, reload);
        }

        return reload;
}

/*
  ____              ____
 |  _ \ ___  __ _  |  _ \ ___  __ _ ___
 | |_) / _ \/ _` | | |_) / _ \/ _` / __|
 |  _ <  __/ (_| | |  _ <  __/ (_| \__ \
 |_| \_\___|\__, | |_| \_\___|\__, |___/
            |___/                |_|

*/


static const
arch_register_req_t *get_out_reg_req(const ir_node *irn, int out_pos)
{
        const be_node_attr_t *a = get_irn_attr(irn);

        if(out_pos >= ARR_LEN(a->reg_data)) {
                return arch_no_register_req;
        }

        return &a->reg_data[out_pos].req.req;
}

static const
arch_register_req_t *get_in_reg_req(const ir_node *irn, int pos)
{
        const be_node_attr_t *a = get_irn_attr(irn);

        if(pos >= get_irn_arity(irn) || pos >= ARR_LEN(a->reg_data))
                return arch_no_register_req;

        return &a->reg_data[pos].in_req.req;
}

static const arch_register_req_t *
be_node_get_irn_reg_req(const void *self, const ir_node *irn, int pos)
{
        int out_pos = pos;

        (void) self;
        if (pos < 0) {
                if (get_irn_mode(irn) == mode_T)
                        return arch_no_register_req;

                out_pos = redir_proj((const ir_node **)&irn);
                assert(is_be_node(irn));
                return get_out_reg_req(irn, out_pos);
        } else if (is_be_node(irn)) {
                /*
                 * For spills and reloads, we return "none" as requirement for frame
                 * pointer, so every input is ok. Some backends need this (e.g. STA).
                 */
                if ((be_is_Spill(irn)  && pos == be_pos_Spill_frame) ||
                                (be_is_Reload(irn) && pos == be_pos_Reload_frame))
                        return arch_no_register_req;

                return get_in_reg_req(irn, pos);
        }

        return arch_no_register_req;
}

const arch_register_t *
be_node_get_irn_reg(const void *self, const ir_node *irn)
{
        be_reg_data_t *r;

        (void) self;
        if (get_irn_mode(irn) == mode_T)
                return NULL;
        r = retrieve_reg_data(irn);
        return r->reg;
}

static arch_irn_class_t be_node_classify(const void *self, const ir_node *irn)
{
        redir_proj((const ir_node **) &irn);

        (void) self;
        switch(be_get_irn_opcode(irn)) {
#define XXX(a,b) case beo_ ## a: return arch_irn_class_ ## b
                XXX(Spill, spill);
                XXX(Reload, reload);
                XXX(Perm, perm);
                XXX(Copy, copy);
                XXX(Return, branch);
#undef XXX
                default:
                return arch_irn_class_normal;
        }

        return 0;
}

static arch_irn_flags_t be_node_get_flags(const void *self, const ir_node *node)
{
        be_req_t *bereq;
        int pos = -1;
        (void) self;

        if(is_Proj(node)) {
                pos = OUT_POS(get_Proj_proj(node));
                node = skip_Proj_const(node);
        }

        bereq = get_be_req(node, pos);

        return bereq->flags;
}

static ir_entity *be_node_get_frame_entity(const void *self, const ir_node *irn)
{
        (void) self;
        return be_get_frame_entity(irn);
}

static void be_node_set_frame_entity(const void *self, ir_node *irn, ir_entity *ent)
{
        be_frame_attr_t *a;
        (void) self;

        assert(be_has_frame_entity(irn));

        a = get_irn_attr(irn);
        a->ent = ent;
}

static void be_node_set_frame_offset(const void *self, ir_node *irn, int offset)
{
        (void) self;
        if(be_has_frame_entity(irn)) {
                be_frame_attr_t *a = get_irn_attr(irn);
                a->offset = offset;
        }
}

static int be_node_get_sp_bias(const void *self, const ir_node *irn)
{
        (void) self;
        return be_is_IncSP(irn) ? be_get_IncSP_offset(irn) : 0;
}

/*
  ___ ____  _   _   _   _                 _ _
 |_ _|  _ \| \ | | | | | | __ _ _ __   __| | | ___ _ __
  | || |_) |  \| | | |_| |/ _` | '_ \ / _` | |/ _ \ '__|
  | ||  _ <| |\  | |  _  | (_| | | | | (_| | |  __/ |
 |___|_| \_\_| \_| |_| |_|\__,_|_| |_|\__,_|_|\___|_|

*/

static const arch_irn_ops_if_t be_node_irn_ops_if = {
        be_node_get_irn_reg_req,
        be_node_set_irn_reg,
        be_node_get_irn_reg,
        be_node_classify,
        be_node_get_flags,
        be_node_get_frame_entity,
        be_node_set_frame_entity,
        be_node_set_frame_offset,
        be_node_get_sp_bias,
        NULL,    /* get_inverse             */
        NULL,    /* get_op_estimated_cost   */
        NULL,    /* possible_memory_operand */
        NULL,    /* perform_memory_operand  */
};

static const arch_irn_ops_t be_node_irn_ops = {
        &be_node_irn_ops_if
};

const void *be_node_get_irn_ops(const arch_irn_handler_t *self, const ir_node *irn)
{
        redir_proj((const ir_node **) &irn);
        (void) self;
        return is_be_node(irn) ? &be_node_irn_ops : NULL;
}

const arch_irn_handler_t be_node_irn_handler = {
        be_node_get_irn_ops
};

/*
  ____  _     _   ___ ____  _   _   _   _                 _ _
 |  _ \| |__ (_) |_ _|  _ \| \ | | | | | | __ _ _ __   __| | | ___ _ __
 | |_) | '_ \| |  | || |_) |  \| | | |_| |/ _` | '_ \ / _` | |/ _ \ '__|
 |  __/| | | | |  | ||  _ <| |\  | |  _  | (_| | | | | (_| | |  __/ |
 |_|   |_| |_|_| |___|_| \_\_| \_| |_| |_|\__,_|_| |_|\__,_|_|\___|_|

*/

typedef struct {
        const arch_register_t *reg;
        arch_register_req_t    req;
        arch_irn_flags_t       flags;
} phi_attr_t;

typedef struct {
        arch_irn_handler_t irn_handler;
        arch_irn_ops_t     irn_ops;
        const arch_env_t   *arch_env;
        pmap               *phi_attrs;
} phi_handler_t;

#define get_phi_handler_from_handler(h)  container_of(h, phi_handler_t, irn_handler)
#define get_phi_handler_from_ops(h)      container_of(h, phi_handler_t, irn_ops)

static
const void *phi_get_irn_ops(const arch_irn_handler_t *handler,
                            const ir_node *irn)
{
        const phi_handler_t *h;
        if(!is_Phi(irn) || !mode_is_datab(get_irn_mode(irn)))
                return NULL;

        h = get_phi_handler_from_handler(handler);
        return &h->irn_ops;
}

static INLINE
phi_attr_t *get_Phi_attr(const phi_handler_t *handler, const ir_node *phi)
{
        phi_attr_t *attr = pmap_get(handler->phi_attrs, (void*) phi);
        if(attr == NULL) {
                ir_graph *irg = get_irn_irg(phi);
                struct obstack *obst = get_irg_obstack(irg);
                attr = obstack_alloc(obst, sizeof(attr[0]));
                memset(attr, 0, sizeof(attr[0]));
                pmap_insert(handler->phi_attrs, phi, attr);
        }

        return attr;
}

/**
 * Get register class of a Phi.
 */
static
const arch_register_req_t *get_Phi_reg_req_recursive(const phi_handler_t *h,
                                                     const ir_node *phi,
                                                     pset **visited)
{
        int n = get_irn_arity(phi);
        ir_node *op;
        int i;

        if(*visited && pset_find_ptr(*visited, phi))
                return NULL;

        for(i = 0; i < n; ++i) {
                op = get_irn_n(phi, i);
                /* Matze: don't we unnecessary constraint our phis with this?
                 * we only need to take the regclass IMO*/
                if(!is_Phi(op))
                        return arch_get_register_req(h->arch_env, op, BE_OUT_POS(0));
        }

        /*
         * The operands of that Phi were all Phis themselves.
         * We have to start a DFS for a non-Phi argument now.
         */
        if(!*visited)
                *visited = pset_new_ptr(16);

        pset_insert_ptr(*visited, phi);

        for(i = 0; i < n; ++i) {
                const arch_register_req_t *req;
                op = get_irn_n(phi, i);
                req = get_Phi_reg_req_recursive(h, op, visited);
                if(req != NULL)
                        return req;
        }

        return NULL;
}

static
const arch_register_req_t *phi_get_irn_reg_req(const void *self,
                                               const ir_node *irn, int pos)
{
        phi_handler_t *phi_handler = get_phi_handler_from_ops(self);
        phi_attr_t *attr;
        (void) self;
        (void) pos;

        if(!mode_is_datab(get_irn_mode(irn)))
                return arch_no_register_req;

        attr = get_Phi_attr(phi_handler, irn);

        if(attr->req.type == arch_register_req_type_none) {
                pset *visited = NULL;
                const arch_register_req_t *req;
                req = get_Phi_reg_req_recursive(phi_handler, irn, &visited);

                memcpy(&attr->req, req, sizeof(req[0]));
                assert(attr->req.cls != NULL);
                attr->req.type = arch_register_req_type_normal;

                if(visited != NULL)
                        del_pset(visited);
        }

        return &attr->req;
}

void be_set_phi_reg_req(const arch_env_t *arch_env, ir_node *node,
                        const arch_register_req_t *req)
{
        const arch_irn_ops_t *ops = arch_get_irn_ops(arch_env, node);
        const phi_handler_t *handler = get_phi_handler_from_ops(ops);
        phi_attr_t *attr;

        assert(mode_is_datab(get_irn_mode(node)));

        attr = get_Phi_attr(handler, node);
        memcpy(&attr->req, req, sizeof(req[0]));
}

void be_set_phi_flags(const arch_env_t *arch_env, ir_node *node,
                      arch_irn_flags_t flags)
{
        const arch_irn_ops_t *ops = arch_get_irn_ops(arch_env, node);
        const phi_handler_t *handler = get_phi_handler_from_ops(ops);
        phi_attr_t *attr;

        assert(mode_is_datab(get_irn_mode(node)));

        attr = get_Phi_attr(handler, node);
        attr->flags = flags;
}

static
void phi_set_irn_reg(const void *self, ir_node *irn, const arch_register_t *reg)
{
        phi_handler_t *h = get_phi_handler_from_ops(self);
        phi_attr_t *attr = get_Phi_attr(h, irn);
        attr->reg = reg;
}

static
const arch_register_t *phi_get_irn_reg(const void *self, const ir_node *irn)
{
        phi_handler_t *h = get_phi_handler_from_ops(self);
        phi_attr_t *attr = get_Phi_attr(h, irn);
        return attr->reg;
}

static
arch_irn_class_t phi_classify(const void *self, const ir_node *irn)
{
        (void) self;
        (void) irn;
        return arch_irn_class_normal;
}

static
arch_irn_flags_t phi_get_flags(const void *self, const ir_node *irn)
{
        phi_handler_t *h = get_phi_handler_from_ops(self);
        phi_attr_t *attr = get_Phi_attr(h, irn);
        (void) self;
        return attr->flags;
}

static
ir_entity *phi_get_frame_entity(const void *self, const ir_node *irn)
{
        (void) self;
        (void) irn;
        return NULL;
}

static
void phi_set_frame_entity(const void *self, ir_node *irn, ir_entity *ent)
{
        (void) self;
        (void) irn;
        (void) ent;
        assert(0);
}

static
void phi_set_frame_offset(const void *self, ir_node *irn, int bias)
{
        (void) self;
        (void) irn;
        (void) bias;
        assert(0);
}

static
int phi_get_sp_bias(const void* self, const ir_node *irn)
{
        (void) self;
        (void) irn;
        return 0;
}

static
const arch_irn_ops_if_t phi_irn_ops = {
        phi_get_irn_reg_req,
        phi_set_irn_reg,
        phi_get_irn_reg,
        phi_classify,
        phi_get_flags,
        phi_get_frame_entity,
        phi_set_frame_entity,
        phi_set_frame_offset,
        phi_get_sp_bias,
        NULL,    /* get_inverse             */
        NULL,    /* get_op_estimated_cost   */
        NULL,    /* possible_memory_operand */
        NULL,    /* perform_memory_operand  */
};

arch_irn_handler_t *be_phi_handler_new(const arch_env_t *arch_env)
{
        phi_handler_t *h           = xmalloc(sizeof(h[0]));
        h->irn_handler.get_irn_ops = phi_get_irn_ops;
        h->irn_ops.impl            = &phi_irn_ops;
        h->arch_env                = arch_env;
        h->phi_attrs               = pmap_create();
        return (arch_irn_handler_t *) h;
}

void be_phi_handler_free(arch_irn_handler_t *handler)
{
        phi_handler_t *h = get_phi_handler_from_handler(handler);
        pmap_destroy(h->phi_attrs);
        h->phi_attrs = NULL;
        free(handler);
}

void be_phi_handler_reset(arch_irn_handler_t *handler)
{
        phi_handler_t *h = get_phi_handler_from_handler(handler);
        if(h->phi_attrs)
                pmap_destroy(h->phi_attrs);
        h->phi_attrs = pmap_create();
}

/*
  _   _           _        ____                        _
 | \ | | ___   __| | ___  |  _ \ _   _ _ __ ___  _ __ (_)_ __   __ _
 |  \| |/ _ \ / _` |/ _ \ | | | | | | | '_ ` _ \| '_ \| | '_ \ / _` |
 | |\  | (_) | (_| |  __/ | |_| | |_| | | | | | | |_) | | | | | (_| |
 |_| \_|\___/ \__,_|\___| |____/ \__,_|_| |_| |_| .__/|_|_| |_|\__, |
                                                |_|            |___/
*/

/**
 * Dumps a register requirement to a file.
 */
static void dump_node_req(FILE *f, int idx, const arch_register_req_t *req,
                          const ir_node *node)
{
        int did_something = 0;
        char buf[16];
        const char *prefix = buf;

        snprintf(buf, sizeof(buf), "#%d ", idx);
        buf[sizeof(buf) - 1] = '\0';

        if(req->cls != 0) {
                char tmp[256];
                fprintf(f, prefix);
                arch_register_req_format(tmp, sizeof(tmp), req, node);
                fprintf(f, "%s", tmp);
                did_something = 1;
        }

        if(did_something)
                fprintf(f, "\n");
}

/**
 * Dumps node register requirements to a file.
 */
static void dump_node_reqs(FILE *f, ir_node *node)
{
        int i;
        be_node_attr_t *a = get_irn_attr(node);
        int len = ARR_LEN(a->reg_data);

        fprintf(f, "registers: \n");
        for(i = 0; i < len; ++i) {
                be_reg_data_t *rd = &a->reg_data[i];
                if(rd->reg)
                        fprintf(f, "#%d: %s\n", i, rd->reg->name);
        }

        fprintf(f, "in requirements:\n");
        for(i = 0; i < len; ++i) {
                dump_node_req(f, i, &a->reg_data[i].in_req.req, node);
        }

        fprintf(f, "\nout requirements:\n");
        for(i = 0; i < len; ++i) {
                dump_node_req(f, i, &a->reg_data[i].req.req, node);
        }
}

/**
 * ir_op-Operation: dump a be node to file
 */
static int dump_node(ir_node *irn, FILE *f, dump_reason_t reason)
{
        be_node_attr_t *at = get_irn_attr(irn);

        assert(is_be_node(irn));

        switch(reason) {
                case dump_node_opcode_txt:
                        fprintf(f, get_op_name(get_irn_op(irn)));
                        break;
                case dump_node_mode_txt:
                        if(be_is_Perm(irn) || be_is_Copy(irn) || be_is_CopyKeep(irn)) {
                                fprintf(f, " %s", get_mode_name(get_irn_mode(irn)));
                        }
                        break;
                case dump_node_nodeattr_txt:
                        if(be_is_Call(irn)) {
                                be_call_attr_t *a = (be_call_attr_t *) at;
                                if (a->ent)
                                        fprintf(f, " [%s] ", get_entity_name(a->ent));
                        }
                        if(be_is_IncSP(irn)) {
                                const be_stack_attr_t *attr = get_irn_generic_attr_const(irn);
                                if(attr->offset == BE_STACK_FRAME_SIZE_EXPAND) {
                                        fprintf(f, " [Setup Stackframe] ");
                                } else if(attr->offset == BE_STACK_FRAME_SIZE_SHRINK) {
                                        fprintf(f, " [Destroy Stackframe] ");
                                } else {
                                        fprintf(f, " [%d] ", attr->offset);
                                }
                        }
                        break;
                case dump_node_info_txt:
                        dump_node_reqs(f, irn);

                        if(be_has_frame_entity(irn)) {
                                be_frame_attr_t *a = (be_frame_attr_t *) at;
                                if (a->ent) {
                                        int bits = get_type_size_bits(get_entity_type(a->ent));
                                        ir_fprintf(f, "frame entity: %+F, offset 0x%x (%d), size 0x%x (%d) bits\n",
                                          a->ent, a->offset, a->offset, bits, bits);
                                }

                        }

                        switch(be_get_irn_opcode(irn)) {
                        case beo_IncSP:
                                {
                                        be_stack_attr_t *a = (be_stack_attr_t *) at;
                                        if (a->offset == BE_STACK_FRAME_SIZE_EXPAND)
                                                fprintf(f, "offset: FRAME_SIZE\n");
                                        else if(a->offset == BE_STACK_FRAME_SIZE_SHRINK)
                                                fprintf(f, "offset: -FRAME SIZE\n");
                                        else
                                                fprintf(f, "offset: %u\n", a->offset);
                                }
                                break;
                        case beo_Call:
                                {
                                        be_call_attr_t *a = (be_call_attr_t *) at;

                                        if (a->ent)
                                                fprintf(f, "\ncalling: %s\n", get_entity_name(a->ent));
                                }
                                break;
                        case beo_MemPerm:
                                {
                                        int i;
                                        for(i = 0; i < be_get_MemPerm_entity_arity(irn); ++i) {
                                                ir_entity *in, *out;
                                                in = be_get_MemPerm_in_entity(irn, i);
                                                out = be_get_MemPerm_out_entity(irn, i);
                                                if(in) {
                                                        fprintf(f, "\nin[%d]: %s\n", i, get_entity_name(in));
                                                }
                                                if(out) {
                                                        fprintf(f, "\nout[%d]: %s\n", i, get_entity_name(out));
                                                }
                                        }
                                }
                                break;

                        default:
                                break;
                        }
        }

        return 0;
}

/**
 * ir_op-Operation:
 * Copies the backend specific attributes from old node to new node.
 */
static void copy_attr(const ir_node *old_node, ir_node *new_node)
{
        be_node_attr_t *old_attr = get_irn_attr(old_node);
        be_node_attr_t *new_attr = get_irn_attr(new_node);
        struct obstack *obst = get_irg_obstack(get_irn_irg(new_node));
        unsigned i, len;

        assert(is_be_node(old_node));
        assert(is_be_node(new_node));

        memcpy(new_attr, old_attr, get_op_attr_size(get_irn_op(old_node)));
        new_attr->reg_data = NULL;

        if(old_attr->reg_data != NULL)
                len = ARR_LEN(old_attr->reg_data);
        else
                len = 0;

        if(get_irn_op(old_node)->opar == oparity_dynamic
                        || be_is_RegParams(old_node)) {
                new_attr->reg_data = NEW_ARR_F(be_reg_data_t, len);
        } else {
                new_attr->reg_data = NEW_ARR_D(be_reg_data_t, obst, len);
        }

        if(len > 0) {
                memcpy(new_attr->reg_data, old_attr->reg_data, len * sizeof(be_reg_data_t));
                for(i = 0; i < len; ++i) {
                        const be_reg_data_t *rd = &old_attr->reg_data[i];
                        be_reg_data_t *newrd = &new_attr->reg_data[i];
                        if(arch_register_req_is(&rd->req.req, limited)) {
                                const arch_register_req_t *req = &rd->req.req;
                                arch_register_req_t *new_req = &newrd->req.req;
                                new_req->limited
                                        = rbitset_duplicate_obstack_alloc(obst, req->limited, req->cls->n_regs);
                        }
                        if(arch_register_req_is(&rd->in_req.req, limited)) {
                                const arch_register_req_t *req = &rd->in_req.req;
                                arch_register_req_t *new_req = &newrd->in_req.req;
                                new_req->limited
                                        = rbitset_duplicate_obstack_alloc(obst, req->limited, req->cls->n_regs);
                        }
                }
        }
}

static const ir_op_ops be_node_op_ops = {
        NULL,
        NULL,
        NULL,
        NULL,
        NULL,
        copy_attr,
        NULL,
        NULL,
        NULL,
        NULL,
        NULL,
        dump_node,
        NULL
};