committing ilp based spilling
[libfirm] / ir / be / becopyilp2.c
index 93cb741..ee02479 100644 (file)
@@ -32,6 +32,9 @@
 
 #ifdef WITH_ILP
 
+#include <bitset.h>
+#include "pdeq.h"
+
 #include "irtools.h"
 #include "irgwalk.h"
 #include "becopyilp_t.h"
 #define DEBUG_LVL 1
 
 typedef struct _local_env_t {
-       firm_dbg_module_t *dbg;
        double time_limit;
        int first_x_var, last_x_var;
        pmap *nr_2_irn;
+       DEBUG_ONLY(firm_dbg_module_t *dbg;)
 } local_env_t;
 
 static void build_coloring_cstr(ilp_env_t *ienv) {
@@ -71,8 +74,10 @@ static void build_coloring_cstr(ilp_env_t *ienv) {
                        /* get assignable colors */
                        if (arch_register_req_is(&req, limited))
                                req.limited(req.limited_env, colors);
-                       else
-                               arch_put_non_ignore_regs(ienv->co->aenv, req.cls, colors);
+                       else {
+                               arch_register_class_put(req.cls, colors);
+                               // bitset_andnot(colors, ienv->co->cenv->ignore_colors);
+                       }
 
                        /* add the coloring constraint */
                        cst_idx = lpp_add_cst(ienv->lp, NULL, lpp_equal, 1.0);
@@ -113,8 +118,13 @@ static void build_interference_cstr(ilp_env_t *ienv) {
 
        /* for each maximal clique */
        be_ifg_foreach_clique(ifg, iter, clique, &size) {
+               int realsize = 0;
+
+               for (i=0; i<size; ++i)
+                       if (!sr_is_removed(ienv->sr, clique[i]))
+                               ++realsize;
 
-               if (size < 2)
+               if (realsize < 2)
                        continue;
 
                /* for all colors */
@@ -134,6 +144,12 @@ static void build_interference_cstr(ilp_env_t *ienv) {
        }
 }
 
+
+/**
+ * TODO: Remove the dependency of the opt-units data structure
+ *       by walking over all affinity edges. Graph structure
+ *       does not provide this walker, yet.
+ */
 static void build_affinity_cstr(ilp_env_t *ienv) {
        unit_t *curr;
        int n_colors = arch_register_class_n_regs(ienv->co->cls);
@@ -166,24 +182,265 @@ static void build_affinity_cstr(ilp_env_t *ienv) {
 
                                lpp_set_factor_fast(ienv->lp, cst_idx, root_idx,  1.0);
                                lpp_set_factor_fast(ienv->lp, cst_idx, arg_idx,  -1.0);
-                               lpp_set_factor_fast(ienv->lp, cst_idx, root_idx, -1.0);
+                               lpp_set_factor_fast(ienv->lp, cst_idx, y_idx, -1.0);
                        }
                }
        }
 }
 
 /**
- *
+ * Helping stuff for build_clique_star_cstr
+ */
+typedef struct _edge_t {
+       ir_node *n1, *n2;
+} edge_t;
+
+static int compare_edge_t(const void *k1, const void *k2, size_t size) {
+       const edge_t *e1 = k1;
+       const edge_t *e2 = k2;
+
+       return ! (e1->n1 == e2->n1   &&   e1->n2 == e2->n2);
+}
+
+#define HASH_EDGE(e) (HASH_PTR((e)->n1) ^ HASH_PTR((e)->n2))
+
+static INLINE edge_t *add_edge(set *edges, ir_node *n1, ir_node *n2, int *counter) {
+       edge_t new_edge;
+
+       if (PTR_TO_INT(n1) < PTR_TO_INT(n2)) {
+               new_edge.n1 = n1;
+               new_edge.n2 = n2;
+       } else {
+               new_edge.n1 = n2;
+               new_edge.n2 = n1;
+       }
+       (*counter)++;
+       return set_insert(edges, &new_edge, sizeof(new_edge), HASH_EDGE(&new_edge));
+}
+
+static INLINE edge_t *find_edge(set *edges, ir_node *n1, ir_node *n2) {
+       edge_t new_edge;
+
+       if (PTR_TO_INT(n1) < PTR_TO_INT(n2)) {
+               new_edge.n1 = n1;
+               new_edge.n2 = n2;
+       } else {
+               new_edge.n1 = n2;
+               new_edge.n2 = n1;
+       }
+       return set_find(edges, &new_edge, sizeof(new_edge), HASH_EDGE(&new_edge));
+}
+
+static INLINE void remove_edge(set *edges, ir_node *n1, ir_node *n2, int *counter) {
+       edge_t new_edge, *e;
+
+       if (PTR_TO_INT(n1) < PTR_TO_INT(n2)) {
+               new_edge.n1 = n1;
+               new_edge.n2 = n2;
+       } else {
+               new_edge.n1 = n2;
+               new_edge.n2 = n1;
+       }
+       e = set_find(edges, &new_edge, sizeof(new_edge), HASH_EDGE(&new_edge));
+       if (e) {
+               e->n1 = NULL;
+               e->n2 = NULL;
+               (*counter)--;
+       }
+}
+
+#define pset_foreach(pset, irn)  for(irn=pset_first(pset); irn; irn=pset_next(pset))
+
+/**
+ * Search for an interference clique and an external node
+ * with affinity edges to all nodes of the clique.
+ * At most 1 node of the clique can be colored equally with the external node.
  */
 static void build_clique_star_cstr(ilp_env_t *ienv) {
+       affinity_node_t *aff;
+
+       /* for each node with affinity edges */
+       co_gs_foreach_aff_node(ienv->co, aff) {
+               struct obstack ob;
+               neighb_t *nbr;
+               ir_node *center = aff->irn;
+               ir_node **nodes;
+               set *edges;
+               int i, o, n_nodes, n_edges;
+
+               obstack_init(&ob);
+               edges = new_set(compare_edge_t, 8);
+
+               /* get all affinity neighbours */
+               n_nodes = 0;
+               co_gs_foreach_neighb(aff, nbr) {
+                       obstack_ptr_grow(&ob, nbr->irn);
+                       ++n_nodes;
+               }
+               nodes = obstack_finish(&ob);
+
+               /* get all interference edges between these */
+               n_edges = 0;
+               for (i=0; i<n_nodes; ++i)
+                       for (o=0; o<i; ++o)
+                               if (be_ifg_connected(ienv->co->cenv->ifg, nodes[i], nodes[o]))
+                                       add_edge(edges, nodes[i], nodes[o], &n_edges);
+
+               /* cover all these interference edges with maximal cliques */
+               while (n_edges) {
+                       edge_t *e;
+                       pset *clique = pset_new_ptr(8);
+                       int growed;
+
+                       /* get 2 starting nodes to form a clique */
+                       for (e=set_first(edges); !e->n1; e=set_next(edges))
+                               /*nothing*/ ;
+
+                       pset_insert_ptr(clique, e->n1);
+                       pset_insert_ptr(clique, e->n2);
+                       remove_edge(edges, e->n1, e->n2, &n_edges);
+
+                       /* while the clique is growing */
+                       do {
+                               growed = 0;
+
+                               /* search for a candidate to extend the clique */
+                               for (i=0; i<n_nodes; ++i) {
+                                       ir_node *member, *cand = nodes[i];
+                                       int is_cand;
+
+                                       /* if its already in the clique try the next */
+                                       if (pset_find_ptr(clique, cand))
+                                               continue;
+
+                                       /* are there all necessary interferences? */
+                                       is_cand = 1;
+                                       pset_foreach(clique, member) {
+                                               if (!find_edge(edges, cand, member)) {
+                                                       is_cand = 0;
+                                                       pset_break(clique);
+                                                       break;
+                                               }
+                                       }
+
+                                       /* now we know if we have a clique extender */
+                                       if (is_cand) {
+                                               /* first remove all covered edges */
+                                               pset_foreach(clique, member)
+                                                       remove_edge(edges, cand, member, &n_edges);
+
+                                               /* insert into clique */
+                                               pset_insert_ptr(clique, cand);
+                                               growed = 1;
+                                               break;
+                                       }
+                               }
+                       } while (growed);
+
+                       /* now the clique is maximal. Finally add the constraint */
+                       {
+                               ir_node *member;
+                               int var_idx, cst_idx, center_nr, member_nr;
+                               char buf[16];
+
+                               cst_idx = lpp_add_cst(ienv->lp, NULL, lpp_greater, pset_count(clique)-1);
+                               center_nr = get_irn_node_nr(center);
+
+                               pset_foreach(clique, member) {
+                                       member_nr = get_irn_node_nr(member);
+                                       var_idx = lpp_get_var_idx(ienv->lp, name_cdd_sorted(buf, 'y', center_nr, member_nr));
+                                       lpp_set_factor_fast(ienv->lp, cst_idx, var_idx, 1.0);
+                               }
+                       }
+
+                       del_pset(clique);
+               }
+
+               del_set(edges);
+               obstack_free(&ob, NULL);
+       }
+}
+
+
+static void extend_path(ilp_env_t *ienv, pdeq *path, ir_node *irn) {
+       be_ifg_t *ifg = ienv->co->cenv->ifg;
+       int i, len;
+       ir_node **curr_path;
+       affinity_node_t *aff;
+       neighb_t *nbr;
+
+       /* do not walk backwards or in circles */
+       if (pdeq_contains(path, irn))
+               return;
+
+       /* insert the new irn */
+       pdeq_putr(path, irn);
+
+
+
+       /* check for forbidden interferences */
+       len = pdeq_len(path);
+       curr_path = alloca(len * sizeof(*curr_path));
+       pdeq_copyl(path, (const void **)curr_path);
+
+       for (i=1; i<len; ++i)
+               if (be_ifg_connected(ifg, irn, curr_path[i]))
+                       goto end;
+
+
+
+       /* check for terminating interference */
+       if (be_ifg_connected(ifg, irn, curr_path[0])) {
+
+               /* One node is not a path. */
+               /* And a path of length 2 is covered by a clique star constraint. */
+               if (len > 2) {
+                       /* finally build the constraint */
+                       int cst_idx = lpp_add_cst(ienv->lp, NULL, lpp_greater, 1.0);
+                       for (i=1; i<len; ++i) {
+                               char buf[16];
+                               int nr_1    = get_irn_node_nr(curr_path[i-1]);
+                               int nr_2    = get_irn_node_nr(curr_path[i]);
+                               int var_idx = lpp_get_var_idx(ienv->lp, name_cdd_sorted(buf, 'y', nr_1, nr_2));
+                               lpp_set_factor_fast(ienv->lp, cst_idx, var_idx, 1.0);
+                       }
+               }
+
+               /* this path cannot be extended anymore */
+               goto end;
+       }
+
+
+
+       /* recursively extend the path */
+       aff = get_affinity_info(ienv->co, irn);
+       co_gs_foreach_neighb(aff, nbr)
+               extend_path(ienv, path, nbr->irn);
+
+
+end:
+       /* remove the irn */
+       pdeq_getr(path);
 
 }
 
 /**
- *
+ *  Search a path of affinity edges, whose ends are connected
+ *  by an interference edge and there are no other interference
+ *  edges in between.
+ *  Then at least one of these affinity edges must break.
  */
 static void build_path_cstr(ilp_env_t *ienv) {
+       affinity_node_t *aff_info;
 
+       /* for each node with affinity edges */
+       co_gs_foreach_aff_node(ienv->co, aff_info) {
+               pdeq *path = new_pdeq();
+
+               extend_path(ienv, path, aff_info->irn);
+
+               del_pdeq(path);
+       }
 }
 
 static void ilp2_build(ilp_env_t *ienv) {
@@ -208,28 +465,32 @@ static void ilp2_apply(ilp_env_t *ienv) {
        lpp_sol_state_t state;
        int i, count;
 
-       count = lenv->last_x_var - lenv->first_x_var + 1;
-       sol = xmalloc(count * sizeof(sol[0]));
-       state = lpp_get_solution(ienv->lp, sol, lenv->first_x_var, lenv->last_x_var);
-       if (state != lpp_optimal) {
-               printf("WARNING %s: Solution state is not 'optimal': %d\n", ienv->co->name, state);
-               assert(state >= lpp_feasible && "The solution should at least be feasible!");
-       }
+       /* first check if there was sth. to optimize */
+       if (lenv->first_x_var >= 0) {
 
-       for (i=0; i<count; ++i) {
-               int nodenr, color;
-               char var_name[16];
+               count = lenv->last_x_var - lenv->first_x_var + 1;
+               sol = xmalloc(count * sizeof(sol[0]));
+               state = lpp_get_solution(ienv->lp, sol, lenv->first_x_var, lenv->last_x_var);
+               if (state != lpp_optimal) {
+                       printf("WARNING %s: Solution state is not 'optimal': %d\n", ienv->co->name, state);
+                       assert(state >= lpp_feasible && "The solution should at least be feasible!");
+               }
+
+               for (i=0; i<count; ++i) {
+                       int nodenr, color;
+                       char var_name[16];
 
-               if (sol[i] > 1-EPSILON) { /* split variable name into components */
-                       lpp_get_var_name(ienv->lp, lenv->first_x_var+i, var_name, sizeof(var_name));
+                       if (sol[i] > 1-EPSILON) { /* split variable name into components */
+                               lpp_get_var_name(ienv->lp, lenv->first_x_var+i, var_name, sizeof(var_name));
 
-                       if (sscanf(var_name, "x_%d_%d", &nodenr, &color) == 2) {
-                               ir_node *irn = pmap_get(lenv->nr_2_irn, INT_TO_PTR(nodenr));
-                               assert(irn && "This node number must be present in the map");
+                               if (sscanf(var_name, "x_%d_%d", &nodenr, &color) == 2) {
+                                       ir_node *irn = pmap_get(lenv->nr_2_irn, INT_TO_PTR(nodenr));
+                                       assert(irn && "This node number must be present in the map");
 
-                               set_irn_col(ienv->co, irn, color);
-                       } else
-                               assert(0 && "This should be a x-var");
+                                       set_irn_col(ienv->co, irn, color);
+                               } else
+                                       assert(0 && "This should be a x-var");
+                       }
                }
        }
 
@@ -247,12 +508,14 @@ int co_solve_ilp2(copy_opt_t *co, double time_limit) {
        ilp_env_t *ienv;
        local_env_t my;
 
+       ASSERT_OU_AVAIL(co); //See build_clique_st
+       ASSERT_GS_AVAIL(co);
+
        my.time_limit  = time_limit;
        my.first_x_var = -1;
        my.last_x_var  = -1;
        my.nr_2_irn    = pmap_create();
-       my.dbg         = firm_dbg_register("ir.be.coilp2");
-       firm_dbg_set_mask(my.dbg, DEBUG_LVL);
+       FIRM_DBG_REGISTER(my.dbg, "firm.be.coilp2");
 
        ienv = new_ilp_env(co, ilp2_build, ilp2_apply, &my);