+/*
+ * This file is part of libFirm.
+ * Copyright (C) 2012 University of Karlsruhe.
+ */
+
/**
- * Author: Daniel Grund
- * Date: 28.02.2006
- * Copyright: (c) Universitaet Karlsruhe
- * Licence: This file protected by GPL - GNU GENERAL PUBLIC LICENSE.
+ * @file
+ * @brief ILP based copy minimization.
+ * @author Daniel Grund
+ * @date 28.02.2006
*
* ILP formalization using G=(V, E, Q):
- * - 1 class of variables: equal color vars
+ * - 2 class of variables: coloring vars x_ic and equal color vars y_ij
* - Path constraints
- * - Clique path constraints
+ * - Clique-star constraints
*
*
- * \min \sum_{ (i,j) \in Q } w_ij y_ij
+ * \min \sum_{ (i,j) \in Q } w_ij y_ij
*
- * y_ij = 1 (i,j) \in E
+ * \sum_c x_nc = 1 n \in N, c \in C
*
- * \sum_c y_nc = |C| - 1 n \in N, c \in C
+ * x_nc = 0 n \in N, c \not\in C(n)
*
- * y_nc = 1 n \in N, c \not\in C(n)
+ * \sum x_nc <= 1 x_nc \in Clique \in AllCliques, c \in C
*
- * \sum_{e \in p} y_e >= 1 p \in P path constraints
+ * \sum_{e \in p} y_e >= 1 p \in P path constraints
*
- * \sum_{e \in cp} y_e >= |cp| - 1 cp \in CP clique-path constraints
+ * \sum_{e \in cs} y_e >= |cs| - 1 cs \in CP clique-star constraints
*
- * y_ij \in N, w_ij \in R^+
+ * x_nc, y_ij \in N, w_ij \in R^+
*/
-
-#ifdef HAVE_CONFIG_H
#include "config.h"
-#endif /* HAVE_CONFIG_H */
-#ifdef WITH_ILP
+#include "be_t.h"
+#include "beintlive_t.h"
+#include "beirg.h"
+#include "bitset.h"
+#include "error.h"
+#include "raw_bitset.h"
+#include "pdeq.h"
+#include "util.h"
+#include "irgwalk.h"
#include "becopyilp_t.h"
+#include "beifg.h"
+#include "besched.h"
+#include "bemodule.h"
+
+DEBUG_ONLY(static firm_dbg_module_t *dbg;)
+
+typedef struct local_env_t {
+ int first_x_var;
+ int last_x_var;
+ const unsigned *allocatable_colors;
+} local_env_t;
+
+static unsigned check_alignment_constraints(ir_node *node)
+{
+ const arch_register_req_t *req = arch_get_irn_register_req(node);
+ // For larger than 1 variables, support only aligned constraints
+ assert((arch_register_req_is(req, aligned) || req->width == 1) && "Unaligned large (width > 1) variables not supported");
+ return arch_register_req_is(req, aligned) && req->width > 1;
+}
+
+static void make_color_var_name(char *buf, size_t buf_size,
+ const ir_node *node, unsigned color)
+{
+ unsigned node_idx = get_irn_idx(node);
+ snprintf(buf, buf_size, "x_%u_%u", node_idx, color);
+}
+
+static void build_coloring_cstr(ilp_env_t *ienv)
+{
+ local_env_t *lenv = (local_env_t*)ienv->env;
+ be_ifg_t *ifg = ienv->co->cenv->ifg;
+ unsigned n_regs = arch_register_class_n_regs(ienv->co->cls);
+ const unsigned *allocatable_colors = lenv->allocatable_colors;
+ char buf[32];
+
+ unsigned *const colors = rbitset_alloca(n_regs);
+ be_ifg_foreach_node(ifg, irn) {
+ const arch_register_req_t *req;
+ unsigned col;
+ int cst_idx;
+ unsigned curr_node_color;
+ unsigned has_alignment_cstr;
+
+ if (sr_is_removed(ienv, irn))
+ continue;
+
+ has_alignment_cstr = check_alignment_constraints(irn);
+
+ req = arch_get_irn_register_req(irn);
+
+ /* get assignable colors */
+ if (arch_register_req_is(req, limited)) {
+ rbitset_copy(colors, req->limited, n_regs);
+ } else {
+ rbitset_copy(colors, allocatable_colors, n_regs);
+ }
-#define DEBUG_LVL 1
+ /* add the coloring constraint */
+ cst_idx = lpp_add_cst(ienv->lp, NULL, lpp_equal, 1.0);
-typedef struct _my_env_t {
- int foo;
-} my_env_t;
+ curr_node_color = get_irn_col(irn);
+ for (col = 0; col < n_regs; ++col) {
+ int var_idx;
+ double val;
+ if (!rbitset_is_set(colors, col)
+ || (has_alignment_cstr && ((col % req->width) != 0)))
+ continue;
+ make_color_var_name(buf, sizeof(buf), irn, col);
+ var_idx = lpp_add_var(ienv->lp, buf, lpp_binary, 0.0);
+ lpp_set_factor_fast(ienv->lp, cst_idx, var_idx, 1);
-static void ilp2_build(ilp_env_t *ienv) {
- ienv->lp = new_lpp(ienv->co->name, lpp_minimize);
+ val = (col == curr_node_color) ? 1.0 : 0.0;
+ lpp_set_start_value(ienv->lp, var_idx, val);
+ lenv->last_x_var = var_idx;
+ if (lenv->first_x_var == -1)
+ lenv->first_x_var = var_idx;
+ }
+
+ /* add register constraint constraints */
+ for (col = 0; col < n_regs; ++col) {
+ int cst_idx;
+ int var_idx;
+ if (rbitset_is_set(colors, col)
+ // for aligned variable, we set the unaligned part to 0
+ && (!has_alignment_cstr || ((col % req->width) == 0)))
+ continue;
+
+ make_color_var_name(buf, sizeof(buf), irn, col);
+ cst_idx = lpp_add_cst(ienv->lp, NULL, lpp_equal, 0.0);
+ var_idx = lpp_add_var(ienv->lp, buf, lpp_binary, 0.0);
+ lpp_set_start_value(ienv->lp, var_idx, 0.0);
+ lpp_set_factor_fast(ienv->lp, cst_idx, var_idx, 1);
+
+ lenv->last_x_var = var_idx;
+ }
+ }
}
-static void ilp2_apply(ilp_env_t *ienv) {
+static void build_interference_cstr(ilp_env_t *ienv)
+{
+ lpp_t *lpp = ienv->lp;
+ local_env_t *lenv = (local_env_t*)ienv->env;
+ be_ifg_t *ifg = ienv->co->cenv->ifg;
+ unsigned n_colors = arch_register_class_n_regs(ienv->co->cls);
+ ir_node **clique = ALLOCAN(ir_node*, n_colors);
+ const unsigned *allocatable_colors = lenv->allocatable_colors;
+ cliques_iter_t iter;
+ int size;
+ unsigned col;
+ int i;
+
+ /* for each maximal clique */
+ be_ifg_foreach_clique(ifg, &iter, clique, &size) {
+ unsigned realsize = 0;
+
+ for (i=0; i<size; ++i) {
+ if (!sr_is_removed(ienv, clique[i]))
+ ++realsize;
+ }
+
+ if (realsize < 2)
+ continue;
+
+ /* for all colors */
+ for (col=0; col<n_colors; ++col) {
+ int cst_idx;
+ if (!rbitset_is_set(allocatable_colors, col))
+ continue;
+ cst_idx = lpp_add_cst(lpp, NULL, lpp_less_equal, 1.0);
+
+ /* for each member of this clique */
+ for (i=0; i<size; ++i) {
+ ir_node *irn = clique[i];
+ char buf[32];
+ int var_idx;
+ unsigned aligment_offset = 0;
+
+ if (sr_is_removed(ienv, irn))
+ continue;
+
+ // Use the first part of the large registers for all
+ // interference, since it is the only colorable one.
+ if (check_alignment_constraints(irn)) {
+ const arch_register_req_t *req
+ = arch_get_irn_register_req(irn);
+ aligment_offset = col % req->width;
+ }
+
+ make_color_var_name(buf, sizeof(buf), irn,
+ col - aligment_offset);
+ var_idx = lpp_get_var_idx(lpp, buf);
+ lpp_set_factor_fast(lpp, cst_idx, var_idx, 1);
+ }
+ }
+ }
}
-int co_solve_ilp2(copy_opt_t *co, double time_limit) {
+static void make_affinity_var_name(char *buf, size_t buf_size,
+ const ir_node *node1, const ir_node *node2)
+{
+ unsigned n1 = get_irn_idx(node1);
+ unsigned n2 = get_irn_idx(node2);
+ if (n1 < n2) {
+ snprintf(buf, buf_size, "y_%u_%u", n1, n2);
+ } else {
+ snprintf(buf, buf_size, "y_%u_%u", n2, n1);
+ }
+}
+
+
+/**
+ * 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)
+{
+ unsigned n_colors = arch_register_class_n_regs(ienv->co->cls);
+
+ /* for all optimization units */
+ list_for_each_entry(unit_t, curr, &ienv->co->units, units) {
+ ir_node *root = curr->nodes[0];
+ unsigned root_col = get_irn_col(root);
+ int i;
+
+ for (i = 1; i < curr->node_count; ++i) {
+ ir_node *arg = curr->nodes[i];
+ unsigned arg_col = get_irn_col(arg);
+ double val;
+ char buf[32];
+ unsigned col;
+ int y_idx;
+
+ /* add a new affinity variable */
+ make_affinity_var_name(buf, sizeof(buf), arg, root);
+ y_idx = lpp_add_var(ienv->lp, buf, lpp_binary, curr->costs[i]);
+ val = (root_col == arg_col) ? 0.0 : 1.0;
+ lpp_set_start_value(ienv->lp, y_idx, val);
+
+ /* add constraints relating the affinity var to the color vars */
+ for (col=0; col<n_colors; ++col) {
+ int cst_idx = lpp_add_cst(ienv->lp, NULL, lpp_less_equal, 0.0);
+ int root_idx;
+ int arg_idx;
+
+ make_color_var_name(buf, sizeof(buf), root, col);
+ root_idx = lpp_get_var_idx(ienv->lp, buf);
+ make_color_var_name(buf, sizeof(buf), arg, col);
+ arg_idx = lpp_get_var_idx(ienv->lp, buf);
+
+ 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, y_idx, -1.0);
+ }
+ }
+ }
+}
+
+/**
+ * Helping stuff for build_clique_star_cstr
+ */
+typedef struct edge_t {
+ ir_node *n1;
+ ir_node *n2;
+} edge_t;
+
+static int compare_edge_t(const void *k1, const void *k2, size_t size)
+{
+ const edge_t *e1 = (const edge_t*)k1;
+ const edge_t *e2 = (const edge_t*)k2;
+ (void) size;
+
+ return ! (e1->n1 == e2->n1 && e1->n2 == e2->n2);
+}
+
+#define HASH_EDGE(e) (hash_irn((e)->n1) ^ hash_irn((e)->n2))
+
+static inline edge_t *add_edge(set *edges, ir_node *n1, ir_node *n2, size_t *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(edge_t, 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(edge_t, edges, &new_edge, sizeof(new_edge), HASH_EDGE(&new_edge));
+}
+
+static inline void remove_edge(set *edges, ir_node *n1, ir_node *n2, size_t *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(edge_t, edges, &new_edge, sizeof(new_edge), HASH_EDGE(&new_edge));
+ if (e) {
+ e->n1 = NULL;
+ e->n2 = NULL;
+ (*counter)--;
+ }
+}
+
+#define pset_foreach(pset, irn) foreach_pset((pset), ir_node, (irn))
+
+/**
+ * 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)
+{
+ /* for each node with affinity edges */
+ be_lv_t *const lv = be_get_irg_liveness(ienv->co->irg);
+ co_gs_foreach_aff_node(ienv->co, aff) {
+ struct obstack ob;
+ const ir_node *center = aff->irn;
+ ir_node **nodes;
+ set *edges;
+ int i, o, n_nodes;
+ size_t n_edges;
+
+ if (arch_irn_is_ignore(aff->irn))
+ continue;
+
+ obstack_init(&ob);
+ edges = new_set(compare_edge_t, 8);
+
+ /* get all affinity neighbours */
+ n_nodes = 0;
+ co_gs_foreach_neighb(aff, nbr) {
+ if (!arch_irn_is_ignore(nbr->irn)) {
+ obstack_ptr_grow(&ob, nbr->irn);
+ ++n_nodes;
+ }
+ }
+ nodes = (ir_node**)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_values_interfere(lv, 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);
+ bool growed;
+
+ /* get 2 starting nodes to form a clique */
+ for (e = set_first(edge_t, edges); !e->n1; e = set_next(edge_t, edges)) {}
+
+ /* we could be stepped out of the loop before the set iterated to the end */
+ set_break(edges);
+
+ 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 = false;
+
+ /* search for a candidate to extend the clique */
+ for (i=0; i<n_nodes; ++i) {
+ ir_node *cand = nodes[i];
+ bool 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 = true;
+ pset_foreach(clique, member) {
+ if (!find_edge(edges, cand, member)) {
+ is_cand = false;
+ 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 = true;
+ break;
+ }
+ }
+ } while (growed);
+
+ /* now the clique is maximal. Finally add the constraint */
+ {
+ int var_idx;
+ int cst_idx;
+ char buf[32];
+
+ cst_idx = lpp_add_cst(ienv->lp, NULL, lpp_greater_equal, pset_count(clique)-1);
+
+ pset_foreach(clique, member) {
+ make_affinity_var_name(buf, sizeof(buf), center, member);
+ var_idx = lpp_get_var_idx(ienv->lp, buf);
+ 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, const ir_node *irn)
+{
+ int i, len;
+ ir_node **curr_path;
+ affinity_node_t *aff;
+
+ /* do not walk backwards or in circles */
+ if (pdeq_contains(path, irn))
+ return;
+
+ if (arch_irn_is_ignore(irn))
+ return;
+
+ /* insert the new irn */
+ pdeq_putr(path, irn);
+
+ /* check for forbidden interferences */
+ len = pdeq_len(path);
+ curr_path = ALLOCAN(ir_node*, len);
+ pdeq_copyl(path, (const void **)curr_path);
+
+ be_lv_t *const lv = be_get_irg_liveness(ienv->co->irg);
+ for (i=1; i<len; ++i) {
+ if (be_values_interfere(lv, irn, curr_path[i]))
+ goto end;
+ }
+
+ /* check for terminating interference */
+ if (be_values_interfere(lv, 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_equal, 1.0);
+ for (i=1; i<len; ++i) {
+ char buf[32];
+ int var_idx;
+
+ make_affinity_var_name(buf, sizeof(buf), curr_path[i-1], curr_path[i]);
+ var_idx = lpp_get_var_idx(ienv->lp, buf);
+ 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)
+{
+ /* 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)
+{
+ int lower_bound;
+
+ ienv->lp = lpp_new("copyilp", lpp_minimize);
+ build_coloring_cstr(ienv);
+ build_interference_cstr(ienv);
+ build_affinity_cstr(ienv);
+ build_clique_star_cstr(ienv);
+ build_path_cstr(ienv);
+
+ lower_bound = co_get_lower_bound(ienv->co) - co_get_inevit_copy_costs(ienv->co);
+ lpp_set_bound(ienv->lp, lower_bound);
+}
+
+static void ilp2_apply(ilp_env_t *ienv)
+{
+ local_env_t *lenv = (local_env_t*)ienv->env;
+ ir_graph *irg = ienv->co->irg;
+
+ /* first check if there was sth. to optimize */
+ if (lenv->first_x_var >= 0) {
+ int count = lenv->last_x_var - lenv->first_x_var + 1;
+ double *sol = XMALLOCN(double, count);
+ lpp_sol_state_t state = lpp_get_solution(ienv->lp, sol, lenv->first_x_var, lenv->last_x_var);
+ int i;
+
+ if (state != lpp_optimal) {
+ ir_printf("WARNING: Solution state of %F register class %s is not 'optimal': %d\n", ienv->co->irg, ienv->co->cls->name, (int)state);
+ if (state < lpp_feasible) {
+ panic("Copy coalescing solution not feasible!");
+ }
+ }
+
+ for (i=0; i<count; ++i) {
+ unsigned nodenr;
+ unsigned color;
+ char var_name[32];
+ if (sol[i] <= 1-EPSILON)
+ continue;
+ /* 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_%u_%u", &nodenr, &color) == 2) {
+ ir_node *irn = get_idx_irn(irg, nodenr);
+ set_irn_col(ienv->co->cls, irn, color);
+ } else {
+ panic("This should be a x-var");
+ }
+ }
+
+ xfree(sol);
+ }
+
+#ifdef COPYOPT_STAT
+ /* TODO adapt to multiple possible ILPs */
+ copystat_add_ilp_time((int)(1000.0*lpp_get_sol_time(pi->curr_lp))); //now we have ms
+ copystat_add_ilp_vars(lpp_get_var_count(pi->curr_lp));
+ copystat_add_ilp_csts(lpp_get_cst_count(pi->curr_lp));
+ copystat_add_ilp_iter(lpp_get_iter_cnt(pi->curr_lp));
+#endif
+}
+
+/**
+ * Solves the problem using mixed integer programming
+ * @returns 1 iff solution state was optimal
+ * Uses the OU and the GRAPH data structure
+ * Dependency of the OU structure can be removed
+ */
+static int co_solve_ilp2(copy_opt_t *co)
+{
+ unsigned n_regs = arch_register_class_n_regs(co->cls);
lpp_sol_state_t sol_state;
- ilp_env_t *ienv;
- my_env_t my;
- firm_dbg_module_t *dbg = firm_dbg_register("ir.be.coilp2");
+ ilp_env_t *ienv;
+ local_env_t my;
+
+ ASSERT_OU_AVAIL(co); //See build_clique_st
+ ASSERT_GS_AVAIL(co);
- firm_dbg_set_mask(dbg, DEBUG_LVL);
+ my.first_x_var = -1;
+ my.last_x_var = -1;
+ FIRM_DBG_REGISTER(dbg, "firm.be.coilp2");
- // my.bla = TODO
+ unsigned *const allocatable_colors = rbitset_alloca(n_regs);
+ be_set_allocatable_regs(co->irg, co->cls, allocatable_colors);
+ my.allocatable_colors = allocatable_colors;
- ienv = new_ilp_env(co, dbg, ilp2_build, ilp2_apply, &my);
+ ienv = new_ilp_env(co, ilp2_build, ilp2_apply, &my);
- sol_state = ilp_go(ienv, time_limit);
+ sol_state = ilp_go(ienv);
free_ilp_env(ienv);
return sol_state == lpp_optimal;
}
-#else /* WITH_ILP */
+BE_REGISTER_MODULE_CONSTRUCTOR(be_init_copyilp2)
+void be_init_copyilp2(void)
+{
+ static co_algo_info copyheur = {
+ co_solve_ilp2, 1
+ };
-static void only_that_you_can_compile_without_WITH_ILP_defined(void) {
+ be_register_copyopt("ilp", ©heur);
}
-
-#endif /* WITH_ILP */
projects / libfirm / blobdiff