[libfirm] / ir / be / beilpsched.c

/**
 * Scheduling algorithms.
 * An ILP scheduler based on
 * "ILP-based Instruction Scheduling for IA-64"
 * by Daniel Kaestner and Sebastian Winkel
 *
 * @date   22.10.2005
 * @author Christian Wuerdig
 * @cvs-id $Id$
 */
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#ifdef WITH_ILP

#include <math.h>

#ifndef _WIN32
#include <strings.h>
#endif /* _WIN32 */

#include "irnode_t.h"
#include "irgwalk.h"
#include "irbitset.h"
#include "irphase_t.h"
#include "iredges.h"
#include "debug.h"
#include "pdeq.h"
#include "irtools.h"
#include "irdump.h"

#include <lpp/lpp.h>
#include <lpp/lpp_net.h>

#ifdef WITH_LIBCORE
#include <libcore/lc_opts.h>
#include <libcore/lc_opts_enum.h>
#include <libcore/lc_timing.h>
#endif /* WITH_LIBCORE */

#include "be.h"
#include "benode_t.h"
#include "besched_t.h"

typedef struct _ilpsched_options_t {
        unsigned time_limit;
        char     log_file[1024];
} ilpsched_options_t;

typedef struct _unit_type_info_t {
        int                            n_units;
        const be_execution_unit_type_t *tp;
} unit_type_info_t;

/**
 * holding the ILP variables of the different types
 */
typedef struct _ilp_var_types_t {
        int *x;   /* x_{nt}^k variables */
        int *d;   /* d_{nt}^k variables */
        int *y;   /* y_{nt}^k variables */
} ilp_var_types_t;

/* attributes for a node */
typedef struct _ilpsched_node_attr_t {
        unsigned asap;                     /**< The ASAP scheduling control step */
        unsigned alap;                     /**< The ALAP scheduling control step */
        unsigned sched_point;              /**< the step in which the node is finally scheduled */
        unsigned visit_idx;                /**< Index of the node having visited this node last */
        unsigned consumer_idx;             /**< Index of the node having counted this node as consumer last */
        unsigned n_consumer;               /**< Number of consumers */
        ir_node  **block_consumer;         /**< List of consumer being in the same block */
        unsigned block_idx : 31;           /**< A unique per block index */
        unsigned enqueued  : 1;            /**< Node is already enqueued for ALAP calculation */
        bitset_t *transitive_block_nodes;  /**< Set of transitive block nodes (predecessors
                                                                                        for ASAP, successors for ALAP */
        unsigned n_unit_types;             /**< number of allowed execution unit types */
        unit_type_info_t *type_info;       /**< list of allowed execution unit types */
        ilp_var_types_t  ilp_vars;         /**< the different ILP variables */
} ilpsched_node_attr_t;

/* attributes for a block */
typedef struct _ilpsched_block_attr_t {
        unsigned block_last_idx;        /**< The highest node index in block so far */
        unsigned n_interesting_nodes;   /**< The number of nodes interesting for scheduling */
        unsigned max_steps;             /**< Upper bound for block execution */
        waitq    *root_nodes;           /**< A queue of nodes having no user in current block */
        ir_node  *head_ilp_nodes;       /**< A linked list of nodes which will contribute to ILP */
} ilpsched_block_attr_t;

typedef union _ilpsched_attr_ {
        ilpsched_node_attr_t  node_attr;
        ilpsched_block_attr_t block_attr;
} ilpsched_attr_t;

/* A irn for the phase and it's attributes (either node or block) */
typedef struct {
        ir_node         *irn;
        ilpsched_attr_t attr;
} be_ilpsched_irn_t;

/* The ILP scheduling environment */
typedef struct {
        phase_t             ph;            /**< The phase */
        ir_graph            *irg;          /**< The current irg */
        waitq               *alap_queue;   /**< An queue of nodes waiting for final ALAP calculation */
        const arch_env_t    *arch_env;
        const be_main_env_t *main_env;
        const be_machine_t  *cpu;          /**< the current abstract machine */
        ilpsched_options_t  *opts;         /**< the ilp options for current irg */
        DEBUG_ONLY(firm_dbg_module_t *dbg);
} be_ilpsched_env_t;

/* convenience macros to handle phase irn data */
#define get_ilpsched_irn(ilpsched_env, irn) (phase_get_or_set_irn_data(&(ilpsched_env)->ph, (irn)))
#define is_ilpsched_block(node)             (is_Block((node)->irn))
#define get_ilpsched_block_attr(block)      (&(block)->attr.block_attr)
#define get_ilpsched_node_attr(node)        (&(node)->attr.node_attr)

/* iterate over a list of ir_nodes linked by link field */
#define foreach_linked_irns(head, iter) for ((iter) = (head); (iter); (iter) = get_irn_link((iter)))

/* check if node is considered for ILP scheduling */
#define consider_for_sched(irn) \
        (! (is_Block(irn)   ||      \
                is_Proj(irn)    ||      \
                is_Phi(irn)     ||      \
                be_is_Keep(irn) ||      \
                is_NoMem(irn)   ||      \
                is_Jmp(irn)     ||      \
                is_End(irn)             \
                ))

/* gives the valid scheduling time step interval for a node */
#define VALID_SCHED_INTERVAL(na) ((na)->alap - (na)->asap + 1)

/* gives the valid interval where a node can die */
#define VALID_KILL_INTERVAL(ba, na) ((ba)->max_steps - (na)->asap + 1)

/* gives the corresponding ILP variable for given node, unit and time step */
#define ILPVAR_IDX(na, unit, control_step) \
        ((unit) * VALID_SCHED_INTERVAL((na)) + (control_step) - (na)->asap + 1)

/* gives the corresponding dead nodes ILP variable for given node, unit and time step */
#define ILPVAR_IDX_DEAD(ba, na, unit, control_step) \
        ((unit) * VALID_KILL_INTERVAL((ba), (na)) + (control_step) - (na)->asap + 1)

/* check if a double value is within an epsilon environment of 0 */
#define LPP_VALUE_IS_0(dbl) (fabs((dbl)) <= 1e-10)

#ifdef WITH_LIBCORE
        #define ilp_timer_push(t)         lc_timer_push((t))
        #define ilp_timer_pop()           lc_timer_pop()
        #define ilp_timer_elapsed_usec(t) lc_timer_elapsed_usec((t))
#else /* WITH_LIBCORE */
        #define ilp_timer_push(t)
        #define ilp_timer_pop()
        #define ilp_timer_elapsed_usec(t) 0.0
#endif /* WITH_LIBCORE */

/* option variable */
static ilpsched_options_t ilp_opts = {
        120,   /* 120 sec per block time limit */
        ""     /* no log file */
};

#ifdef WITH_LIBCORE
/* ILP options */
static const lc_opt_table_entry_t ilpsched_option_table[] = {
        LC_OPT_ENT_INT("time_limit", "ILP time limit per block", &ilp_opts.time_limit),
        LC_OPT_ENT_STR("lpp_log",    "LPP logfile (stderr and stdout are supported)", ilp_opts.log_file, sizeof(ilp_opts.log_file)),
        { NULL }
};
#endif /* WITH_LIBCORE */

/**
 * Compare scheduling time steps of two be_ilpsched_irn's.
 */
static int cmp_ilpsched_irn(const void *a, const void *b) {
        be_ilpsched_irn_t    *n1   = *(be_ilpsched_irn_t **)a;
        be_ilpsched_irn_t    *n2   = *(be_ilpsched_irn_t **)b;
        ilpsched_node_attr_t *n1_a = get_ilpsched_node_attr(n1);
        ilpsched_node_attr_t *n2_a = get_ilpsched_node_attr(n2);

        return QSORT_CMP(n1_a->sched_point, n2_a->sched_point);
}

/**
 * In case there is no phase information for irn, initialize it.
 */
static void *init_ilpsched_irn(phase_t *ph, ir_node *irn, void *old) {
        be_ilpsched_irn_t *res = old ? old : phase_alloc(ph, sizeof(res[0]));

        if (res == old) {
                /* if we have already some data: check for reinitialization */

                if (! is_Block(irn)) {
                        ilpsched_node_attr_t *na = get_ilpsched_node_attr(res);

                        if (! na->transitive_block_nodes) {
                                ir_node               *block      = get_nodes_block(irn);
                                be_ilpsched_irn_t     *block_node = phase_get_or_set_irn_data(ph, block);
                                ilpsched_block_attr_t *ba         = get_ilpsched_block_attr(block_node);

                                /* we are called after the block indicees have been build: create bitset */
                                na->transitive_block_nodes = bitset_obstack_alloc(phase_obst(ph), ba->block_last_idx);
                        }
                        else {
                                /* we are called from reinit block data: clear the bitset */
                                bitset_clear_all(na->transitive_block_nodes);
                                na->visit_idx = 0;
                        }
                }
                return old;
        }

        res->irn = irn;

        /* set ilpsched irn attributes (either block or irn) */
        if (is_Block(irn)) {
                ilpsched_block_attr_t *ba = get_ilpsched_block_attr(res);

                ba->n_interesting_nodes = 0;
                ba->block_last_idx      = 0;
                ba->root_nodes          = new_waitq();
                ba->head_ilp_nodes      = NULL;
        }
        else {
                ilpsched_node_attr_t *na = get_ilpsched_node_attr(res);
                memset(na, 0, sizeof(*na));
        }

        return res;
}

/**
 * Assign a per block unique number to each node.
 */
static void build_block_idx(ir_node *irn, void *walk_env) {
        be_ilpsched_env_t     *env = walk_env;
        be_ilpsched_irn_t     *node, *block_node;
        ilpsched_node_attr_t  *na;
        ilpsched_block_attr_t *ba;

        if (! consider_for_sched(irn))
                return;

        node       = get_ilpsched_irn(env, irn);
        na         = get_ilpsched_node_attr(node);
        block_node = get_ilpsched_irn(env, get_nodes_block(irn));
        ba         = get_ilpsched_block_attr(block_node);

        na->block_idx = ba->block_last_idx++;
}

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

/**
 * Add all nodes having no user in current block to last_nodes list.
 */
static void collect_alap_root_nodes(ir_node *irn, void *walk_env) {
        ir_node               *block;
        const ir_edge_t       *edge;
        be_ilpsched_irn_t     *block_node, *node;
        ilpsched_block_attr_t *ba;
        ilpsched_node_attr_t  *na;
        int                   i, j;
        be_ilpsched_env_t     *env           = walk_env;
        int                   has_block_user = 0;
        unsigned              n_consumer     = 0;
        ir_edge_kind_t        ekind[2]       = { EDGE_KIND_NORMAL, EDGE_KIND_DEP };
        ir_node               **consumer;
        int                   idx;

        if (! consider_for_sched(irn))
                return;

        block    = get_nodes_block(irn);
    idx      = get_irn_idx(irn);
        consumer = NEW_ARR_F(ir_node *, 0);

        DBG((env->dbg, LEVEL_3, "%+F (%+F) is interesting, examining ... ", irn, block));

        /* check data and dependency out edges */
        for (i = 0; i < 2 && ! has_block_user; ++i) {
                foreach_out_edge_kind(irn, edge, ekind[i]) {
                        ir_node *user = get_edge_src_irn(edge);

                        if (is_Proj(user)) {
                                const ir_edge_t *user_edge;

                                if (get_irn_mode(user) == mode_X)
                                        continue;

                                /* The ABI ensures, that there will be no ProjT nodes in the graph. */
                                for (j = 0; j < 2; ++j) {
                                        foreach_out_edge_kind(user, user_edge, ekind[j]) {
                                                ir_node *real_user = get_edge_src_irn(user_edge);

                                                if (! is_Phi(real_user) && ! be_is_Keep(real_user)) {
                                                        be_ilpsched_irn_t    *node = get_ilpsched_irn(env, real_user);
                                                        ilpsched_node_attr_t *ua   = get_ilpsched_node_attr(node);

                                                        /* skip already visited nodes */
                                                        if (ua->consumer_idx == idx)
                                                                continue;

                                                        /* check if node has user in this block and collect the user if it's a data user */
                                                        if (get_nodes_block(real_user) == block) {
                                                                if (i == 0 && j == 0)
                                                                        ARR_APP1(ir_node *, consumer, real_user);
                                                                has_block_user = 1;
                                                        }

                                                        /* only count data consumer */
                                                        if (i == 0)
                                                                n_consumer++;

                                                        /* mark user as visited by this node */
                                                        ua->consumer_idx = idx;
                                                }
                                        }
                                }
                        }
                        else if (is_Block(user)) {
                                continue;
                        }
                        else if (! is_Phi(user) && ! be_is_Keep(user)) {
                                be_ilpsched_irn_t    *node = get_ilpsched_irn(env, user);
                                ilpsched_node_attr_t *ua   = get_ilpsched_node_attr(node);

                                /* skip already visited nodes */
                                if (ua->consumer_idx == idx)
                                        continue;

                                /* check if node has user in this block and collect the user if it's a data user */
                                if (get_nodes_block(user) == block) {
                                        if (i == 0)
                                                ARR_APP1(ir_node *, consumer, user);
                                        has_block_user = 1;
                                }

                                /* only count data consumer */
                                if (i == 0)
                                        n_consumer++;

                                /* mark user visited by this node */
                                ua->consumer_idx = idx;
                        }
                }
        }

        block_node = get_ilpsched_irn(env, block);
        ba         = get_ilpsched_block_attr(block_node);

        ba->n_interesting_nodes++;

        /* current irn has no user inside this block, add to queue */
        if (! has_block_user) {
                DB((env->dbg, LEVEL_3, "root node\n"));
                waitq_put(ba->root_nodes, irn);
        }
        else {
                DB((env->dbg, LEVEL_3, "normal node\n"));
        }

        /* record number of all consumer and the consumer within the same block */
        node = get_ilpsched_irn(env, irn);
        na   = get_ilpsched_node_attr(node);
        na->n_consumer     = n_consumer;
        na->block_consumer = NEW_ARR_D(ir_node *, phase_obst(&env->ph), ARR_LEN(consumer));
        memcpy(na->block_consumer, consumer, ARR_LEN(consumer) * sizeof(na->block_consumer[0]));
        DEL_ARR_F(consumer);
}

/**
 * Calculate the ASAP scheduling step for current irn.
 */
static void calculate_irn_asap(ir_node *irn, void *walk_env) {
        be_ilpsched_irn_t *node;
        be_ilpsched_env_t *env = walk_env;
        int      i;
        ir_node  *block;
        ilpsched_node_attr_t *na;

        /* These nodes are handled separate */
        if (! consider_for_sched(irn))
                return;

        DBG((env->dbg, LEVEL_2, "Calculating ASAP of node %+F\n", irn));

        node  = get_ilpsched_irn(env, irn);
        block = get_nodes_block(irn);
        na    = get_ilpsched_node_attr(node);

        /* accumulate all transitive predecessors of current node */
        for (i = get_irn_ins_or_deps(irn) - 1; i >= 0; --i) {
                ir_node              *pred = skip_Proj(get_irn_in_or_dep(irn, i));
                be_ilpsched_irn_t    *pred_node;
                ilpsched_node_attr_t *pna;
                unsigned             idx;

                if (be_is_Keep(pred))
                        pred = skip_Proj(get_irn_n(pred, 0));

                if (is_Phi(pred) || block != get_nodes_block(pred) || is_NoMem(pred))
                        continue;

                pred_node = get_ilpsched_irn(env, pred);
                pna       = get_ilpsched_node_attr(pred_node);
                idx       = get_irn_idx(irn);

                assert(pna->asap && "missing ASAP of predecessor");

                /*
                        We have not already visited this predecessor
                        -> accumulate it's predecessors
                */
                if (pna->visit_idx != idx) {
                        pna->visit_idx = idx;
                        na->transitive_block_nodes = bitset_or(na->transitive_block_nodes, pna->transitive_block_nodes);
                        DBG((env->dbg, LEVEL_3, "\taccumulating preds of %+F\n", pred));
                }
        }

        /* every node is it's own transitive predecessor in block */
        bitset_set(na->transitive_block_nodes, na->block_idx);

        /* asap = number of transitive predecessors in this block */
        na->asap = bitset_popcnt(na->transitive_block_nodes);

        DBG((env->dbg, LEVEL_2, "\tcalculated ASAP is %u\n", na->asap));
}

/**
 * Accumulate the successors of all nodes from irn on upwards.
 */
static void accumulate_succs(be_ilpsched_env_t *env, ir_node *irn) {
        unsigned             i, n;
        be_ilpsched_irn_t    *node  = get_ilpsched_irn(env, irn);
        ilpsched_node_attr_t *na    = get_ilpsched_node_attr(node);
        ir_node              *block = get_nodes_block(irn);
        waitq                *wq    = new_waitq();

        DBG((env->dbg, LEVEL_3, "\taccumulating succs of %+F\n", irn));

        /* enqueue node for final alap calculation */
        if (! na->enqueued) {
                be_ilpsched_irn_t     *block_node = get_ilpsched_irn(env, block);
                ilpsched_block_attr_t *ba         = get_ilpsched_block_attr(block_node);

                na->enqueued = 1;
                na->alap     = ba->n_interesting_nodes;
                waitq_put(env->alap_queue, node);

                set_irn_link(irn, ba->head_ilp_nodes);
                ba->head_ilp_nodes = irn;
                DBG((env->dbg, LEVEL_5, "\t\tlinked %+F to ilp nodes of %+F, attr %p\n", irn, block, ba));
                DBG((env->dbg, LEVEL_4, "\t\tenqueueing %+F for final ALAP calculation\n", irn));
        }

        for (i = 0, n = get_irn_ins_or_deps(irn); i < n; ++i) {
                ir_node              *pred = skip_Proj(get_irn_in_or_dep(irn, i));
                unsigned             idx;
                be_ilpsched_irn_t    *pred_node;
                ilpsched_node_attr_t *pna;

                if (be_is_Keep(pred))
                        pred = skip_Proj(get_irn_n(pred, 0));

                if (is_Phi(pred) || block != get_nodes_block(pred) || is_NoMem(pred))
                        continue;

                pred_node = get_ilpsched_irn(env, pred);
                pna       = get_ilpsched_node_attr(pred_node);
                idx       = get_irn_idx(irn);

                /* accumulate the successors */
                if (pna->visit_idx != idx) {
                        pna->visit_idx = idx;
                        pna->transitive_block_nodes = bitset_or(pna->transitive_block_nodes, na->transitive_block_nodes);

                        /* set current node as successor */
                        bitset_set(pna->transitive_block_nodes, na->block_idx);
                        waitq_put(wq, pred);

                        DBG((env->dbg, LEVEL_3, "\taccumulating succs of %+F to %+F\n", irn, pred));
                }
        }

        /* process all predecessors */
        while (! waitq_empty(wq)) {
                accumulate_succs(env, waitq_get(wq));
        }

        del_waitq(wq);
}

/**
 * Calculate the ALAP scheduling step of all irns in current block.
 * Depends on ASAP being calculated.
 */
static void calculate_block_alap(ir_node *block, void *walk_env) {
        be_ilpsched_env_t     *env        = walk_env;
        be_ilpsched_irn_t     *block_node = get_ilpsched_irn(env, block);
        ilpsched_block_attr_t *ba         = get_ilpsched_block_attr(block_node);

        assert(is_Block(block));

        DBG((env->dbg, LEVEL_2, "Calculating ALAP for nodes in %+F (%u nodes)\n", block, ba->n_interesting_nodes));

        /* TODO: Might be faster to use out edges and call phase_reinit_single_irn_data */
        phase_reinit_block_irn_data(&env->ph, block);

        /* calculate the alap of all nodes, starting at collected roots upwards */
        while (! waitq_empty(ba->root_nodes)) {
                accumulate_succs(env, waitq_get(ba->root_nodes));
        }

        /* we don't need it anymore */
        del_waitq(ba->root_nodes);
        ba->root_nodes = NULL;

        /* all interesting nodes should have their successors accumulated now */
        while (! waitq_empty(env->alap_queue)) {
                be_ilpsched_irn_t    *node = waitq_get(env->alap_queue);
                ilpsched_node_attr_t *na   = get_ilpsched_node_attr(node);

                /* control flow ops must always be scheduled last */
                if (is_cfop(node->irn) && ! is_Start(node->irn) && get_irn_opcode(node->irn) != iro_End)
                        na->asap = na->alap;
                else
                        na->alap -= bitset_popcnt(na->transitive_block_nodes);
                DBG((env->dbg, LEVEL_2, "\tALAP of %+F is %u (%u succs, %u consumer)\n",
                        node->irn, na->alap, bitset_popcnt(na->transitive_block_nodes), na->n_consumer));

                /* maximum block steps is maximum alap of all nodes */
                ba->max_steps = MAX(ba->max_steps, na->alap);
        }
}

/*******************************************
 *           _              _       _
 *          | |            | |     | |
 *  ___  ___| |__   ___  __| |_   _| | ___
 * / __|/ __| '_ \ / _ \/ _` | | | | |/ _ \
 * \__ \ (__| | | |  __/ (_| | |_| | |  __/
 * |___/\___|_| |_|\___|\__,_|\__,_|_|\___|
 *
 *******************************************/

static INLINE void check_for_keeps(waitq *keeps, ir_node *block, ir_node *irn) {
        const ir_edge_t *edge;

        foreach_out_edge(irn, edge) {
                ir_node *user = get_edge_src_irn(edge);

                if (be_is_Keep(user)) {
                        assert(get_nodes_block(user) == block && "Keep must not be in different block.");
                        waitq_put(keeps, user);
                }
        }
}

/**
 * Adds a node, it's Projs (in case of mode_T nodes) and
 * it's Keeps to schedule.
 */
static void add_to_sched(ir_node *block, ir_node *irn) {
        const ir_edge_t *edge;
        waitq           *keeps = new_waitq();

        /* mode_M nodes are not scheduled */
        if (get_irn_mode(irn) == mode_M)
                return;

        sched_add_before(block, irn);

        /* add Projs */
        if (get_irn_mode(irn) == mode_T) {
                foreach_out_edge(irn, edge) {
                        ir_node *user = get_edge_src_irn(edge);

                        assert(is_Proj(user) && "User of mode_T node must be a Proj");

                        if (to_appear_in_schedule(user))
                                sched_add_before(block, user);

                        check_for_keeps(keeps, block, user);
                }
        }
        else {
                check_for_keeps(keeps, block, irn);
        }

        /* add Keeps */
        while (! waitq_empty(keeps)) {
                ir_node *keep = waitq_get(keeps);
                if (! sched_is_scheduled(keep))
                        sched_add_before(block, keep);
        }

        del_waitq(keeps);
}

/**
 * Schedule all nodes in the given block, according to the ILP solution.
 */
static void apply_solution(be_ilpsched_env_t *env, lpp_t *lpp, ir_node *block) {
        be_ilpsched_irn_t     *block_node = get_ilpsched_irn(env, block);
        ilpsched_block_attr_t *ba         = get_ilpsched_block_attr(block_node);
        sched_info_t          *info       = get_irn_sched_info(block);
        be_ilpsched_irn_t     **sched_nodes;
        unsigned              i, l;
        ir_node               *cfop, *irn;
        const ir_edge_t       *edge;

        /* init block schedule list */
        INIT_LIST_HEAD(&info->list);
        info->scheduled = 1;

        /* collect nodes and their scheduling time step */
        sched_nodes = NEW_ARR_F(be_ilpsched_irn_t *, 0);
        if (ba->n_interesting_nodes == 0) {
                /* ignore */
        }
        else if (ba->n_interesting_nodes == 1) {
                be_ilpsched_irn_t *node = get_ilpsched_irn(env, ba->head_ilp_nodes);

                /* add the single node */
                ARR_APP1(be_ilpsched_irn_t *, sched_nodes, node);
        }
        else {
                /* check all nodes for their positive solution */
                foreach_linked_irns(ba->head_ilp_nodes, irn) {
                        be_ilpsched_irn_t    *node;
                        ilpsched_node_attr_t *na;
                        int                  tp_idx, found;
                        unsigned             cur_var, t;

                        node    = get_ilpsched_irn(env, irn);
                        na      = get_ilpsched_node_attr(node);
                        cur_var = 0;
                        found   = 0;

                        /* go over all variables of a node until the non-zero one is found */
                        for (tp_idx = na->n_unit_types - 1; ! found && tp_idx >= 0; --tp_idx) {
                                for (t = na->asap - 1; ! found && t <= na->alap - 1; ++t) {
                                        double val = lpp_get_var_sol(lpp, na->ilp_vars.x[cur_var++]);

                                        /* check, if variable is set to one (it's not zero then :) */
                                        if (! LPP_VALUE_IS_0(val)) {
                                                na->sched_point = t;
                                                ARR_APP1(be_ilpsched_irn_t *, sched_nodes, node);
                                                DBG((env->dbg, LEVEL_1, "Schedpoint of %+F is %u at unit type %s\n",
                                                        irn, t, na->type_info[tp_idx].tp->name));
                                                found = 1;
                                        }
                                }
                        }
                }

                /* sort nodes ascending by scheduling time step */
                qsort(sched_nodes, ARR_LEN(sched_nodes), sizeof(sched_nodes[0]), cmp_ilpsched_irn);
        }

        /* make all Phis ready and remember the single cf op */
        cfop = NULL;
        foreach_out_edge(block, edge) {
                irn = get_edge_src_irn(edge);

                switch (get_irn_opcode(irn)) {
                        case iro_Phi:
                                add_to_sched(block, irn);
                                break;
                        case iro_Start:
                        case iro_End:
                        case iro_Proj:
                        case iro_Bad:
                                break;
                        default:
                                if (is_cfop(irn)) {
                                        assert(cfop == NULL && "Highlander - there can be only one");
                                        cfop = irn;
                                }
                        break;
                }
        }

        /* add all nodes from list */
        for (i = 0, l = ARR_LEN(sched_nodes); i < l; ++i) {
                add_to_sched(block, sched_nodes[i]->irn);
        }

        /* schedule control flow node if not already done */
        if (cfop && ! sched_is_scheduled(cfop))
                add_to_sched(block, cfop);

        DEL_ARR_F(sched_nodes);
}

/***************************************************************
 *   _____ _      _____     _____           _   _
 *  |_   _| |    |  __ \   / ____|         | | (_)
 *    | | | |    | |__) | | (___   ___  ___| |_ _  ___  _ __
 *    | | | |    |  ___/   \___ \ / _ \/ __| __| |/ _ \| '_ \
 *   _| |_| |____| |       ____) |  __/ (__| |_| | (_) | | | |
 *  |_____|______|_|      |_____/ \___|\___|\__|_|\___/|_| |_|
 *
 ***************************************************************/

/**
 * Check if node can be executed on given unit type.
 */
static INLINE int is_valid_unit_type_for_node(const be_execution_unit_type_t *tp, be_ilpsched_irn_t *node) {
        int                  i;
        ilpsched_node_attr_t *na = get_ilpsched_node_attr(node);

        for (i = na->n_unit_types - 1; i >= 0; --i) {
                if (na->type_info[i].tp == tp)
                        return i;
        }

        return -1;
}

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

/**
 * Create the following variables:
 * - x_{nt}^k    binary     weigthed with: t
 *      node n is scheduled at time step t to unit type k
 * ==>> These variables represent the schedule
 * TODO:
 *
 * - d_{nt}^k    binary     weighted with: t
 *      node n dies at time step t on unit type k
 *
 * - y_{nt}^k    binary     weighted with: num_nodes^2
 *      node n is scheduled at time step t to unit type k
 *      although all units of this type are occupied
 * ==>> These variables represent the register pressure
 */
static void create_variables(be_ilpsched_env_t *env, lpp_t *lpp, be_ilpsched_irn_t *block_node, struct obstack *var_obst) {
        char                  buf[1024];
        ir_node               *irn;
        unsigned              num_block_var, num_nodes;
        ilpsched_block_attr_t *ba      = get_ilpsched_block_attr(block_node);
        unsigned              weigth_y = ba->n_interesting_nodes * ba->n_interesting_nodes;
#ifdef WITH_LIBCORE
        lc_timer_t            *t_var   = lc_timer_register("beilpsched_var", "create ilp variables");
#endif /* WITH_LIBCORE */

        ilp_timer_push(t_var);
        num_block_var = num_nodes = 0;
        foreach_linked_irns(ba->head_ilp_nodes, irn) {
                const be_execution_unit_t ***execunits = arch_isa_get_allowed_execution_units(env->arch_env->isa, irn);
                be_ilpsched_irn_t         *node;
                ilpsched_node_attr_t      *na;
                unsigned                  n_unit_types, tp_idx, unit_idx, n_var, cur_unit;
                unsigned                  cur_var_d, cur_var_x, cur_var_y, num_die;

                /* count number of available unit types for this node */
                for (n_unit_types = 0; execunits[n_unit_types]; ++n_unit_types)
                        /* just count */ ;

                node = get_ilpsched_irn(env, irn);
                na   = get_ilpsched_node_attr(node);

                na->n_unit_types = n_unit_types;
                na->type_info    = NEW_ARR_D(unit_type_info_t, var_obst, n_unit_types);

                /* fill the type info array */
                for (tp_idx = 0; tp_idx < n_unit_types; ++tp_idx) {
                        for (unit_idx = 0; execunits[tp_idx][unit_idx]; ++unit_idx)
                                /* just count units of this type */;

                        na->type_info[tp_idx].tp      = execunits[tp_idx][0]->tp;
                        na->type_info[tp_idx].n_units = unit_idx;
                }

                /* allocate space for ilp variables */
                na->ilp_vars.x = NEW_ARR_D(int, var_obst, n_unit_types * VALID_SCHED_INTERVAL(na));
                na->ilp_vars.y = NEW_ARR_D(int, var_obst, n_unit_types * VALID_SCHED_INTERVAL(na));
                memset(na->ilp_vars.x, -1, ARR_LEN(na->ilp_vars.x) * sizeof(na->ilp_vars.x[0]));
                memset(na->ilp_vars.y, -1, ARR_LEN(na->ilp_vars.y) * sizeof(na->ilp_vars.y[0]));

                num_die        = ba->max_steps - na->asap + 1;
                na->ilp_vars.d = NEW_ARR_D(int, var_obst, n_unit_types * num_die);
                memset(na->ilp_vars.d, -1, ARR_LEN(na->ilp_vars.d) * sizeof(na->ilp_vars.d[0]));

                DBG((env->dbg, LEVEL_3, "\thandling %+F (asap %u, alap %u, unit types %u):\n",
                        irn, na->asap, na->alap, na->n_unit_types));

                cur_var_x = cur_var_d = cur_var_y = cur_unit = n_var = 0;
                /* create variables */
                for (tp_idx = 0; tp_idx < n_unit_types; ++tp_idx) {
                        unsigned t;

                        for (t = na->asap - 1; t <= na->alap - 1; ++t) {
                                /* x_{nt}^k variables */
                                snprintf(buf, sizeof(buf), "x_n%u_%s_%u",
                                        get_irn_idx(irn), na->type_info[tp_idx].tp->name, t);
                                na->ilp_vars.x[cur_var_x++] = lpp_add_var(lpp, buf, lpp_binary, (double)(t + 1));
                                DBG((env->dbg, LEVEL_4, "\t\tcreated ILP variable %s\n", buf));

                                /* y_{nt}^k variables */
                                snprintf(buf, sizeof(buf), "y_n%u_%s_%u",
                                        get_irn_idx(irn), na->type_info[tp_idx].tp->name, t);
                                na->ilp_vars.y[cur_var_y++] = lpp_add_var(lpp, buf, lpp_binary, (double)(weigth_y));
                                DBG((env->dbg, LEVEL_4, "\t\tcreated ILP variable %s\n", buf));

                                /* variable counter */
                                n_var         += 2;
                                num_block_var += 2;
                        }

                        /* a node can die at any step t: asap(n) <= t <= U */
                        for (t = na->asap - 1; t <= ba->max_steps; ++t) {
                                /* d_{nt}^k variables */
                                snprintf(buf, sizeof(buf), "d_n%u_%s_%u",
                                        get_irn_idx(irn), na->type_info[tp_idx].tp->name, t);
                                na->ilp_vars.d[cur_var_d++] = lpp_add_var(lpp, buf, lpp_binary, (double)(t + 1));
                                DBG((env->dbg, LEVEL_4, "\t\tcreated ILP variable %s\n", buf));

                                /* variable counter */
                                n_var++;
                                num_block_var++;
                        }
                }

                DB((env->dbg, LEVEL_3, "%u variables created\n", n_var));
                num_nodes++;
        }
        ilp_timer_pop();
        DBG((env->dbg, LEVEL_1, "... %u variables for %u nodes created (%g sec)\n",
                num_block_var, num_nodes, ilp_timer_elapsed_usec(t_var) / 1000000.0));
}

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

/**
 * Create following ILP constraints:
 * - the assignment constraints:
 *     assure each node is executed once by exactly one (allowed) execution unit
 * - the dead node assignment constraints:
 *     assure a node can only die at most once
 * - the precedence constraints:
 *     assure that no data dependencies are violated
 */
static void create_assignment_and_precedence_constraints(be_ilpsched_env_t *env, lpp_t *lpp, be_ilpsched_irn_t *block_node) {
        unsigned              num_cst_assign, num_cst_prec, num_cst_dead;
        char                  buf[1024];
        ir_node               *irn;
        ilpsched_block_attr_t *ba            = get_ilpsched_block_attr(block_node);
        bitset_t              *bs_block_irns = bitset_alloca(ba->block_last_idx);
#ifdef WITH_LIBCORE
        lc_timer_t            *t_cst_assign  = lc_timer_register("beilpsched_cst_assign",      "create assignment constraints");
        lc_timer_t            *t_cst_dead    = lc_timer_register("beilpsched_cst_assign_dead", "create dead node assignment constraints");
        lc_timer_t            *t_cst_prec    = lc_timer_register("beilpsched_cst_prec",        "create precedence constraints");
#endif /* WITH_LIBCORE */

        num_cst_assign = num_cst_prec = num_cst_dead = 0;
        foreach_linked_irns(ba->head_ilp_nodes, irn) {
                int                  cst, tp_idx, i;
                unsigned             cur_var;
                be_ilpsched_irn_t    *node;
                ilpsched_node_attr_t *na;

                node    = get_ilpsched_irn(env, irn);
                na      = get_ilpsched_node_attr(node);
                cur_var = 0;

                /* the assignment constraint */
                ilp_timer_push(t_cst_assign);
                snprintf(buf, sizeof(buf), "assignment_cst_n%u", get_irn_idx(irn));
                cst = lpp_add_cst_uniq(lpp, buf, lpp_equal, 1.0);
                DBG((env->dbg, LEVEL_2, "added constraint %s\n", buf));
                num_cst_assign++;

                lpp_set_factor_fast_bulk(lpp, cst, na->ilp_vars.x, ARR_LEN(na->ilp_vars.x), 1.0);
                ilp_timer_pop();

                /* the dead node assignment constraint */
                ilp_timer_push(t_cst_dead);
                snprintf(buf, sizeof(buf), "dead_node_assign_cst_n%u", get_irn_idx(irn));
                cst = lpp_add_cst_uniq(lpp, buf, lpp_less, 1.0);
                DBG((env->dbg, LEVEL_2, "added constraint %s\n", buf));

                lpp_set_factor_fast_bulk(lpp, cst, na->ilp_vars.d, ARR_LEN(na->ilp_vars.d), 1.0);
                ilp_timer_pop();

                /* the precedence constraints */
                ilp_timer_push(t_cst_prec);
                bs_block_irns = bitset_clear_all(bs_block_irns);
                for (i = get_irn_ins_or_deps(irn) - 1; i >= 0; --i) {
                        ir_node              *pred = skip_Proj(get_irn_in_or_dep(irn, i));
                        unsigned             t_low, t_high, t;
                        be_ilpsched_irn_t    *pred_node;
                        ilpsched_node_attr_t *pna;

                        if (be_is_Keep(pred))
                                pred = skip_Proj(get_irn_n(pred, 0));

                        if (is_Phi(pred) || block_node->irn != get_nodes_block(pred) || is_NoMem(pred))
                                continue;

                        pred_node = get_ilpsched_irn(env, pred);
                        pna       = get_ilpsched_node_attr(pred_node);

                        assert(pna->asap > 0 && pna->alap >= pna->asap && "Invalid scheduling interval.");

                        if (! bitset_is_set(bs_block_irns, pna->block_idx))
                                bitset_set(bs_block_irns, pna->block_idx);
                        else
                                continue;

                        /* irn = n, pred = m */
                        t_low  = MAX(na->asap, pna->asap);
                        t_high = MIN(na->alap, pna->alap);
                        for (t = t_low - 1; t <= t_high - 1; ++t) {
                                int tn, tm, cur_idx;
                                int int_na       = (t >= na->asap - 1) ? t - na->asap + 2 : 0;
                                int int_pna      = (t < pna->alap)     ? pna->alap - t    : 0;
                                int *tmp_var_idx = NEW_ARR_F(int, int_na * na->n_unit_types + int_pna * pna->n_unit_types);

                                snprintf(buf, sizeof(buf), "precedence_n%u_n%u_%u", get_irn_idx(pred), get_irn_idx(irn), t);
                                cst = lpp_add_cst_uniq(lpp, buf, lpp_less, 1.0);
                                DBG((env->dbg, LEVEL_2, "added constraint %s\n", buf));
                                num_cst_prec++;

                                cur_idx = 0;

                                /* lpp_set_factor_fast_bulk needs variables sorted ascending by index */
                                if (na->ilp_vars.x[0] < pna->ilp_vars.x[0]) {
                                        /* node variables have smaller index than pred variables */
                                        for (tp_idx = na->n_unit_types - 1; tp_idx >= 0; --tp_idx) {
                                                for (tn = na->asap - 1; tn <= t; ++tn) {
                                                        unsigned idx = ILPVAR_IDX(na, tp_idx, tn);
                                                        tmp_var_idx[cur_idx++] = na->ilp_vars.x[idx];
                                                }
                                        }

                                        for (tp_idx = pna->n_unit_types - 1; tp_idx >= 0; --tp_idx) {
                                                for (tm = t; tm < pna->alap; ++tm) {
                                                        unsigned idx = ILPVAR_IDX(pna, tp_idx, tm);
                                                        tmp_var_idx[cur_idx++] = pna->ilp_vars.x[idx];
                                                }
                                        }
                                }
                                else {
                                        /* pred variables have smaller index than node variables */
                                        for (tp_idx = pna->n_unit_types - 1; tp_idx >= 0; --tp_idx) {
                                                for (tm = t; tm < pna->alap; ++tm) {
                                                        unsigned idx = ILPVAR_IDX(pna, tp_idx, tm);
                                                        tmp_var_idx[cur_idx++] = pna->ilp_vars.x[idx];
                                                }
                                        }

                                        for (tp_idx = na->n_unit_types - 1; tp_idx >= 0; --tp_idx) {
                                                for (tn = na->asap - 1; tn <= t; ++tn) {
                                                        unsigned idx = ILPVAR_IDX(na, tp_idx, tn);
                                                        tmp_var_idx[cur_idx++] = na->ilp_vars.x[idx];
                                                }
                                        }
                                }

                                lpp_set_factor_fast_bulk(lpp, cst, tmp_var_idx, ARR_LEN(tmp_var_idx), 1.0);

                                DEL_ARR_F(tmp_var_idx);
                        }
                }
                ilp_timer_pop();
        }
        DBG((env->dbg, LEVEL_1, "\t%u assignement constraints (%g sec)\n",
                num_cst_assign, ilp_timer_elapsed_usec(t_cst_assign) / 1000000.0));
        DBG((env->dbg, LEVEL_1, "\t%u precedence constraints (%g sec)\n",
                num_cst_prec, ilp_timer_elapsed_usec(t_cst_prec) / 1000000.0));
}

/**
 * Create ILP resource constraints:
 * - assure that for each time step not more instructions are scheduled
 *   to the same unit types as units of this type are available
 */
static void create_ressource_constraints(be_ilpsched_env_t *env, lpp_t *lpp, be_ilpsched_irn_t *block_node) {
        int                   glob_type_idx;
        char                  buf[1024];
        unsigned              num_cst_resrc = 0;
        ilpsched_block_attr_t *ba           = get_ilpsched_block_attr(block_node);
#ifdef WITH_LIBCORE
        lc_timer_t            *t_cst_rsrc   = lc_timer_register("beilpsched_cst_rsrc",   "create resource constraints");
#endif /* WITH_LIBCORE */

        ilp_timer_push(t_cst_rsrc);
        for (glob_type_idx = env->cpu->n_unit_types - 1; glob_type_idx >= 0; --glob_type_idx) {
                unsigned                 t;
                be_execution_unit_type_t *cur_tp = &env->cpu->unit_types[glob_type_idx];

                for (t = 0; t < ba->max_steps; ++t) {
                        ir_node *irn;
                        int     cst;
                        int     *tmp_var_idx = NEW_ARR_F(int, ba->max_steps);
                        int     cur_idx      = 0;

                        snprintf(buf, sizeof(buf), "resource_cst_%s_%u", cur_tp->name, t);
                        cst = lpp_add_cst_uniq(lpp, buf, lpp_less, (double)cur_tp->n_units);
                        DBG((env->dbg, LEVEL_2, "added constraint %s\n", buf));
                        num_cst_resrc++;

                        foreach_linked_irns(ba->head_ilp_nodes, irn) {
                                be_ilpsched_irn_t    *node = get_ilpsched_irn(env, irn);
                                ilpsched_node_attr_t *na   = get_ilpsched_node_attr(node);
                                int                  tp_idx;

                                tp_idx = is_valid_unit_type_for_node(cur_tp, node);

                                if (tp_idx >= 0 && t >= na->asap - 1 && t <= na->alap - 1) {
                                        int cur_var = ILPVAR_IDX(na, tp_idx, t);
                                        tmp_var_idx[cur_idx++] = na->ilp_vars.x[cur_var];
                                }
                        }

                        /* set constraints if we have some */
                        if (cur_idx)
                                lpp_set_factor_fast_bulk(lpp, cst, tmp_var_idx, ARR_LEN(tmp_var_idx), 1.0);

                        DEL_ARR_F(tmp_var_idx);
                }
        }
        ilp_timer_pop();
        DBG((env->dbg, LEVEL_1, "\t%u resource constraints (%g sec)\n",
                num_cst_resrc, ilp_timer_elapsed_usec(t_cst_rsrc) / 1000000.0));
}

/**
 * Create ILP bundle constraints:
 * - assure, at most bundle_size * bundles_per_cycle instructions
 *   can be started at a certain point.
 */
static void create_bundle_constraints(be_ilpsched_env_t *env, lpp_t *lpp, be_ilpsched_irn_t *block_node) {
        char                  buf[1024];
        unsigned              t;
        unsigned              num_cst_bundle = 0;
        unsigned              n_instr_max    = env->cpu->bundle_size * env->cpu->bundels_per_cycle;
        ilpsched_block_attr_t *ba            = get_ilpsched_block_attr(block_node);
#ifdef WITH_LIBCORE
        lc_timer_t            *t_cst_bundle  = lc_timer_register("beilpsched_cst_bundle", "create bundle constraints");
#endif /* WITH_LIBCORE */

        ilp_timer_push(t_cst_bundle);
        for (t = 0; t < ba->max_steps; ++t) {
                ir_node *irn;
                int     cst;
                int     *tmp_var_idx = NEW_ARR_F(int, 0);

                snprintf(buf, sizeof(buf), "bundle_cst_%u", t);
                cst = lpp_add_cst_uniq(lpp, buf, lpp_less, (double)n_instr_max);
                DBG((env->dbg, LEVEL_2, "added constraint %s\n", buf));
                num_cst_bundle++;

                foreach_linked_irns(ba->head_ilp_nodes, irn) {
                        be_ilpsched_irn_t    *node;
                        ilpsched_node_attr_t *na;
                        int                  tp_idx;

                        node = get_ilpsched_irn(env, irn);
                        na   = get_ilpsched_node_attr(node);

                        if (t >= na->asap - 1 && t <= na->alap - 1) {
                                for (tp_idx = na->n_unit_types - 1; tp_idx >= 0; --tp_idx) {
                                        int idx = ILPVAR_IDX(na, tp_idx, t);
                                        ARR_APP1(int, tmp_var_idx, na->ilp_vars.x[idx]);
                                }
                        }
                }

                if (ARR_LEN(tmp_var_idx) > 0)
                        lpp_set_factor_fast_bulk(lpp, cst, tmp_var_idx, ARR_LEN(tmp_var_idx), 1.0);

                DEL_ARR_F(tmp_var_idx);
        }
        ilp_timer_pop();
        DBG((env->dbg, LEVEL_1, "\t%u bundle constraints (%g sec)\n",
                num_cst_bundle, ilp_timer_elapsed_usec(t_cst_bundle) / 1000000.0));
}

/**
 * Create ILP dying nodes constraints:
 * - set variable d_{nt}^k to 1 if nodes n dies at step t on unit k
 */
static void create_dying_nodes_constraint(be_ilpsched_env_t *env, lpp_t *lpp, be_ilpsched_irn_t *block_node) {
        char                  buf[1024];
        unsigned              t;
        unsigned              num_cst = 0;
        ilpsched_block_attr_t *ba     = get_ilpsched_block_attr(block_node);
#ifdef WITH_LIBCORE
        lc_timer_t            *t_cst  = lc_timer_register("beilpsched_cst_dying_nodes", "create dying nodes constraints");
#endif /* WITH_LIBCORE */

        ilp_timer_push(t_cst);
        /* check all time_steps */
        for (t = 0; t < ba->max_steps; ++t) {
                ir_node *irn;

                /* for all nodes */
                foreach_linked_irns(ba->head_ilp_nodes, irn) {
                        be_ilpsched_irn_t    *node = get_ilpsched_irn(env, irn);
                        ilpsched_node_attr_t *na   = get_ilpsched_node_attr(node);

                        /* if node has no consumer within current block, it cannot die here */
                        if (ARR_LEN(na->block_consumer) < 1)
                                continue;

                        /* node can only die here if t at least asap(n) */
                        if (t >= na->asap - 1) {
                                int node_tp_idx;

                                /* for all unit types */
                                for (node_tp_idx = na->n_unit_types - 1; node_tp_idx >= 0; --node_tp_idx) {
                                        int tp_idx, i, cst;
                                        int *tmp_var_idx = NEW_ARR_F(int, 0);

                                        snprintf(buf, sizeof(buf), "dying_node_cst_%u_n%u", t, get_irn_idx(irn));
                                        cst = lpp_add_cst_uniq(lpp, buf, lpp_less, (double)(na->n_consumer - 1));
                                        DBG((env->dbg, LEVEL_2, "added constraint %s\n", buf));
                                        num_cst++;

                                        /* number of consumer scheduled till t */
                                        for (i = ARR_LEN(na->block_consumer) - 1; i >= 0; --i) {
                                                be_ilpsched_irn_t    *cons = get_ilpsched_irn(env, na->block_consumer[i]);
                                                ilpsched_node_attr_t *ca   = get_ilpsched_node_attr(cons);

                                                for (tp_idx = ca->n_unit_types - 1; tp_idx >= 0; --tp_idx) {
                                                        unsigned tm;

                                                        for (tm = ca->asap - 1; tm <= t && tm <= ca->alap - 1; ++tm) {
                                                                int idx = ILPVAR_IDX(ca, tp_idx, tm);
                                                                ARR_APP1(int, tmp_var_idx, ca->ilp_vars.x[idx]);
                                                        }
                                                }
                                        }

                                        /* could be that no consumer can be scheduled at this point */
                                        if (ARR_LEN(tmp_var_idx)) {
                                                int      idx;
                                                unsigned tn;

                                                /* subtract possible prior kill points */
                                                for (tn = na->asap - 1; tn < t; ++tn) {
                                                        idx = ILPVAR_IDX_DEAD(ba, na, node_tp_idx, tn);
                                                        lpp_set_factor_fast(lpp, cst, na->ilp_vars.d[idx], -1.0);
                                                }

                                                idx = ILPVAR_IDX_DEAD(ba, na, node_tp_idx, t);
                                                lpp_set_factor_fast(lpp, cst, na->ilp_vars.d[idx], 0.0 - (double)(na->n_consumer));
                                                lpp_set_factor_fast_bulk(lpp, cst, tmp_var_idx, ARR_LEN(tmp_var_idx), 1.0);
                                        }

                                        DEL_ARR_F(tmp_var_idx);
                                }
                        }

                }
        }
        ilp_timer_pop();
        DBG((env->dbg, LEVEL_1, "\t%u dying nodes constraints (%g sec)\n",
                num_cst, ilp_timer_elapsed_usec(t_cst) / 1000000.0));
}

/**
* Create ILP pressure constraints:
* - add additional costs to objective function if a node is scheduled
*   on a unit although all units of this type are currently occupied
*/
static void create_pressure_constraint(be_ilpsched_env_t *env, lpp_t *lpp, be_ilpsched_irn_t *block_node) {
        char                  buf[1024];
        unsigned              t;
        unsigned              num_cst = 0;
        ilpsched_block_attr_t *ba     = get_ilpsched_block_attr(block_node);
#ifdef WITH_LIBCORE
        lc_timer_t            *t_cst  = lc_timer_register("beilpsched_cst_pressure", "create pressure constraints");
#endif /* WITH_LIBCORE */

        ilp_timer_push(t_cst);
        /* check all time_steps */
        for (t = 0; t < ba->max_steps; ++t) {
                int glob_type_idx;

                /* for all types */
                for (glob_type_idx = env->cpu->n_unit_types - 1; glob_type_idx >= 0; --glob_type_idx) {
                        be_execution_unit_type_t *cur_tp = &env->cpu->unit_types[glob_type_idx];
                        int                      cst;

                        snprintf(buf, sizeof(buf), "pressure_cst_%u_%s", t, cur_tp->name);
                        cst = lpp_add_cst_uniq(lpp, buf, lpp_less, (double)(cur_tp->n_units - 1));
                        DBG((env->dbg, LEVEL_2, "added constraint %s\n", buf));
                        num_cst++;

                        /* to be continued ... */
                }
        }
        ilp_timer_pop();
        DBG((env->dbg, LEVEL_1, "\t%u pressure constraints (%g sec)\n",
                num_cst, ilp_timer_elapsed_usec(t_cst) / 1000000.0));
}

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

/**
 * Create the ilp (add variables, build constraints, solve, build schedule from solution).
 */
static void create_ilp(ir_node *block, void *walk_env) {
        be_ilpsched_env_t     *env           = walk_env;
        be_ilpsched_irn_t     *block_node    = get_ilpsched_irn(env, block);
        ilpsched_block_attr_t *ba            = get_ilpsched_block_attr(block_node);
        FILE                  *logfile       = NULL;
        lpp_t                 *lpp           = NULL;
        struct obstack        var_obst;

        DBG((env->dbg, 255, "\n\n\n=========================================\n"));
        DBG((env->dbg, 255, "  ILP Scheduling for %+F\n", block));
        DBG((env->dbg, 255, "=========================================\n\n"));

        DBG((env->dbg, LEVEL_1, "Creating ILP Variables for nodes in %+F (%u interesting nodes)\n",
                block, ba->n_interesting_nodes));

        /* if we have less than two interesting nodes, there is no need to create the ILP */
        if (ba->n_interesting_nodes > 1) {
                double fact_var        = ba->n_interesting_nodes > 25 ? 1.1 : 1.2;
                double fact_cst        = ba->n_interesting_nodes > 25 ? 0.7 : 1.5;
                int    base_num        = ba->n_interesting_nodes * ba->n_interesting_nodes;
                int    estimated_n_var = (int)((double)base_num * fact_var);
                int    estimated_n_cst = (int)((double)base_num * fact_cst);

                DBG((env->dbg, LEVEL_1, "Creating LPP with estimed numbers: %d vars, %d cst\n",
                        estimated_n_var, estimated_n_cst));

                /* set up the LPP object */
                lpp = new_lpp_userdef(
                        "be ilp scheduling",
                        lpp_minimize,
                        estimated_n_cst + 1,  /* num vars */
                        estimated_n_cst + 20, /* num cst */
                        1.2);                 /* grow factor */
                obstack_init(&var_obst);

                /* create ILP variables */
                create_variables(env, lpp, block_node, &var_obst);

                /* create ILP constraints */
                DBG((env->dbg, LEVEL_1, "Creating constraints for nodes in %+F:\n", block));
                create_assignment_and_precedence_constraints(env, lpp, block_node);
                create_ressource_constraints(env, lpp, block_node);
                create_bundle_constraints(env, lpp, block_node);
                create_dying_nodes_constraint(env, lpp, block_node);

                DBG((env->dbg, LEVEL_1, "ILP to solve: %u variables, %u constraints\n", lpp->var_next, lpp->cst_next));

                /* debug stuff, dump lpp when debugging is on  */
                DEBUG_ONLY(
                        if (firm_dbg_get_mask(env->dbg) > 0) {
                                char buf[1024];
                                FILE *f;

                                snprintf(buf, sizeof(buf), "lpp_block_%lu.txt", get_irn_node_nr(block));
                                f = fopen(buf, "w");
                                lpp_dump_plain(lpp, f);
                                fclose(f);
                                snprintf(buf, sizeof(buf), "lpp_block_%lu.mps", get_irn_node_nr(block));
                                lpp_dump(lpp, buf);
                        }
                );

                /* set solve time limit */
                lpp_set_time_limit(lpp, env->opts->time_limit);

                /* set logfile if requested */
                if (strlen(env->opts->log_file) > 0) {
                        if (strcasecmp(env->opts->log_file, "stdout") == 0)
                                lpp_set_log(lpp, stdout);
                        else if (strcasecmp(env->opts->log_file, "stderr") == 0)
                                lpp_set_log(lpp, stderr);
                        else {
                                logfile = fopen(env->opts->log_file, "w");
                                if (! logfile)
                                        fprintf(stderr, "Could not open logfile '%s'! Logging disabled.\n", env->opts->log_file);
                                else
                                        lpp_set_log(lpp, logfile);
                        }
                }

                /* solve the ILP */
                lpp_solve_net(lpp, env->main_env->options->ilp_server, env->main_env->options->ilp_solver);

                if (logfile)
                        fclose(logfile);

                /* check for valid solution */
                if (! lpp_is_sol_valid(lpp)) {
                        char buf[1024];
                        FILE *f;

                        snprintf(buf, sizeof(buf), "lpp_block_%lu.assert.txt", get_irn_node_nr(block));
                        f = fopen(buf, "w");
                        lpp_dump_plain(lpp, f);
                        fclose(f);
                        snprintf(buf, sizeof(buf), "lpp_block_%lu.assert.mps", get_irn_node_nr(block));
                        lpp_dump(lpp, buf);
                        dump_ir_block_graph(env->irg, "-assert");

                        assert(0 && "ILP solution is not feasible!");
                }

                DBG((env->dbg, LEVEL_1, "\nSolution:\n"));
                DBG((env->dbg, LEVEL_1, "\tsend time: %g sec\n", lpp->send_time / 1000000.0));
                DBG((env->dbg, LEVEL_1, "\treceive time: %g sec\n", lpp->recv_time / 1000000.0));
                DBG((env->dbg, LEVEL_1, "\titerations: %d\n", lpp->iterations));
                DBG((env->dbg, LEVEL_1, "\tsolution time: %g\n", lpp->sol_time));
                DBG((env->dbg, LEVEL_1, "\tobjective function: %g\n", LPP_VALUE_IS_0(lpp->objval) ? 0.0 : lpp->objval));
                DBG((env->dbg, LEVEL_1, "\tbest bound: %g\n", LPP_VALUE_IS_0(lpp->best_bound) ? 0.0 : lpp->best_bound));

                DBG((env->dbg, LEVEL_1, "variables used %u bytes\n", obstack_memory_used(&var_obst)));
        }

        /* apply solution */
        apply_solution(env, lpp, block);

        if (lpp)
                free_lpp(lpp);
}

/**
 * Perform ILP scheduling on the given irg.
 */
void be_ilp_sched(const be_irg_t *birg) {
        be_ilpsched_env_t env;
        const char        *name = "be ilp scheduling";

        FIRM_DBG_REGISTER(env.dbg, "firm.be.sched.ilp");

        //firm_dbg_set_mask(env.dbg, 31);

        env.irg        = birg->irg;
        env.main_env   = birg->main_env;
        env.alap_queue = new_waitq();
        env.arch_env   = birg->main_env->arch_env;
        env.cpu        = arch_isa_get_machine(birg->main_env->arch_env->isa);
        env.opts       = &ilp_opts;
        phase_init(&env.ph, name, env.irg, PHASE_DEFAULT_GROWTH, init_ilpsched_irn);

        /* assigne a unique per block number to all interesting nodes */
        irg_walk_in_or_dep_graph(env.irg, NULL, build_block_idx, &env);

        /*
                The block indicees are completely build after the walk,
                now we can allocate the bitsets (size depends on block indicees)
                for all nodes.
        */
        phase_reinit_irn_data(&env.ph);

        /* Collect all root nodes (having no user in their block) and calculate ASAP. */
        irg_walk_in_or_dep_blkwise_graph(env.irg, collect_alap_root_nodes, calculate_irn_asap, &env);

        /* calculate ALAP and perform ILP scheduling */
        irg_block_walk_graph(env.irg, calculate_block_alap, create_ilp, &env);

        DEBUG_ONLY(
                if (firm_dbg_get_mask(env.dbg)) {
                        phase_stat_t stat;
                        phase_stat_t *stat_ptr = phase_stat(&env.ph, &stat);

                        fprintf(stderr, "Phase used: %u bytes\n", stat_ptr->overall_bytes);
                }
        );

        /* free all allocated object */
        del_waitq(env.alap_queue);
        phase_free(&env.ph);
}

#ifdef WITH_LIBCORE
/**
 * Register ILP scheduler options.
 */
void ilpsched_register_options(lc_opt_entry_t *grp) {
        static int     run_once = 0;
        lc_opt_entry_t *sched_grp;

        if (! run_once) {
                run_once  = 1;
                sched_grp = lc_opt_get_grp(grp, "ilpsched");

                lc_opt_add_table(sched_grp, ilpsched_option_table);
        }
}
#endif /* WITH_LIBCORE */

#else /* WITH_ILP */

static int some_picky_compiler_do_not_allow_empty_files;

#endif /* WITH_ILP */