--- /dev/null
+/*
+ * Copyright (C) 1995-2007 University of Karlsruhe. All right reserved.
+ *
+ * This file is part of libFirm.
+ *
+ * This file may be distributed and/or modified under the terms of the
+ * GNU General Public License version 2 as published by the Free Software
+ * Foundation and appearing in the file LICENSE.GPL included in the
+ * packaging of this file.
+ *
+ * Licensees holding valid libFirm Professional Edition licenses may use
+ * this file in accordance with the libFirm Commercial License.
+ * Agreement provided with the Software.
+ *
+ * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
+ * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE.
+ */
+
+/**
+ * @file
+ * @brief Naiv spilling algorithm
+ * @author Matthias Braun
+ * @date 20.09.2005
+ * @version $Id: bespillbelady.c 13913 2007-05-18 12:48:56Z matze $
+ * @summary
+ * This implements a naiv spilling algorithm. It is design to produce similar
+ * effects to the spill decisions produced by traditional graph coloring
+ * register allocators that spill while they are coloring the graph.
+ *
+ * This spiller walks over all blocks and looks for places with too high
+ * register pressure where it spills the values that are cheapest to spill.
+ * Spilling in this context means placing a spill instruction behind the
+ * definition of the value and a reload before each usage.
+ */
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include "debug.h"
+
+#include "irnodeset.h"
+#include "irgwalk.h"
+#include "irprintf.h"
+#include "iredges_t.h"
+#include "error.h"
+
+#include "beirg.h"
+#include "bespilloptions.h"
+#include "bespill.h"
+#include "bemodule.h"
+#include "besched.h"
+#include "bearch_t.h"
+#include "be_t.h"
+#include "benode_t.h"
+#include "beirg.h"
+
+DEBUG_ONLY(static firm_dbg_module_t *dbg = NULL;)
+
+typedef struct daemel_env_t daemel_env_t;
+struct daemel_env_t {
+ spill_env_t *spill_env;
+ int n_regs;
+ const arch_env_t *arch_env;
+ const arch_register_class_t *cls;
+ const be_lv_t *lv;
+ bitset_t *spilled_nodes;
+};
+
+typedef struct spill_candidate_t spill_candidate_t;
+struct spill_candidate_t {
+ double costs;
+ ir_node *node;
+};
+
+static
+int compare_spill_candidates_desc(const void *d1, const void *d2)
+{
+ const spill_candidate_t *c1 = d1;
+ const spill_candidate_t *c2 = d2;
+
+ return (int) (c1->costs - c2->costs);
+}
+
+static
+double get_spill_costs(daemel_env_t *env, ir_node *node)
+{
+ const ir_edge_t *edge;
+ spill_env_t *spill_env = env->spill_env;
+ double costs = be_get_spill_costs(spill_env, node, node);
+
+ foreach_out_edge(node, edge) {
+ ir_node *use = get_edge_src_irn(edge);
+
+ if(is_Phi(use)) {
+ int in = get_edge_src_pos(edge);
+ ir_node *block = get_nodes_block(use);
+
+ costs += be_get_reload_costs_on_edge(spill_env, node, block, in);
+ } else {
+ costs += be_get_reload_costs(spill_env, node, use);
+ }
+ }
+
+ return costs;
+}
+
+/**
+ * spills a node by placing a reload before each usage
+ */
+static
+void spill_node(daemel_env_t *env, ir_node *node, ir_nodeset_t *nodes)
+{
+ const ir_edge_t *edge;
+ spill_env_t *spill_env = env->spill_env;
+ const arch_register_class_t *cls = env->cls;
+
+ DBG((dbg, LEVEL_3, "\tspilling %+F\n", node));
+
+ foreach_out_edge(node, edge) {
+ ir_node *use = get_edge_src_irn(edge);
+
+ if(is_Phi(use)) {
+ int in = get_edge_src_pos(edge);
+ ir_node *block = get_nodes_block(use);
+
+ be_add_reload_on_edge(spill_env, node, block, in, cls, 1);
+ } else if(!be_is_Keep(use)) {
+ be_add_reload(spill_env, node, use, cls, 1);
+ }
+ }
+
+ bitset_set(env->spilled_nodes, get_irn_idx(node));
+ ir_nodeset_remove(nodes, node);
+}
+
+/**
+ * spill @p n nodes from a nodeset. Removes the nodes from the nodeset and
+ * sets the spilled bits in env->spilled_nodes.
+ */
+static
+void do_spilling(daemel_env_t *env, ir_nodeset_t *nodes, ir_node *node,
+ ir_node *spill_phis_in)
+{
+ size_t node_count = ir_nodeset_size(nodes);
+ size_t additional_defines = 0;
+ int registers = env->n_regs;
+ const arch_env_t *arch_env = env->arch_env;
+ const arch_register_class_t *cls = env->cls;
+ spill_candidate_t *candidates;
+ ir_nodeset_iterator_t iter;
+ size_t i, arity;
+ int spills_needed;
+ int cand_idx;
+ ir_node *n;
+
+ /* mode_T nodes define several values at once. Count them */
+ if(get_irn_mode(node) == mode_T) {
+ ir_node *proj = sched_next(node);
+
+ while(is_Proj(proj)) {
+ if(arch_irn_consider_in_reg_alloc(arch_env, cls, proj)) {
+ ++additional_defines;
+ }
+ proj = sched_next(proj);
+ }
+ }
+
+ spills_needed = (node_count + additional_defines) - registers;
+ if(spills_needed <= 0)
+ return;
+ DBG((dbg, LEVEL_2, "\tspills needed after %+F: %d\n", node, spills_needed));
+
+ candidates = malloc(node_count * sizeof(candidates[0]));
+
+ /* construct array with spill candidates and calculate their costs */
+ i = 0;
+ foreach_ir_nodeset(nodes, n, iter) {
+ spill_candidate_t *candidate = & candidates[i];
+
+ candidate->node = n;
+ candidate->costs = get_spill_costs(env, n);
+ ++i;
+ }
+ assert(i == node_count);
+
+ /* sort spill candidates */
+ qsort(candidates, node_count, sizeof(candidates[0]),
+ compare_spill_candidates_desc);
+
+ /* spill cheapest ones */
+ cand_idx = 0;
+ arity = get_irn_arity(node);
+ while(spills_needed > 0) {
+ spill_candidate_t *candidate = &candidates[cand_idx];
+ ir_node *cand_node = candidate->node;
+ int is_use;
+ ++cand_idx;
+
+ if(cand_idx >= node_count) {
+ panic("can't spill enough values for node %+F\n", node);
+ }
+
+ /* make sure the node is not a use of the instruction */
+ is_use = 0;
+ for(i = 0; i < arity; ++i) {
+ ir_node *in = get_irn_n(node, i);
+ if(in == cand_node) {
+ is_use = 1;
+ break;
+ }
+ }
+ if(is_use) {
+ continue;
+ }
+
+ spill_node(env, cand_node, nodes);
+ --spills_needed;
+ if(spill_phis_in != NULL && is_Phi(node) &&
+ get_nodes_block(node) == spill_phis_in) {
+ DBG((dbg, LEVEL_3, "\tspilled phi\n"));
+ be_spill_phi(env->spill_env, node);
+ }
+ }
+
+ free(candidates);
+}
+
+/**
+ * similar to be_liveness_transfer.
+ * custom liveness transfer function, that doesn't place already spilled values
+ * into the liveness set
+ */
+static
+void liveness_transfer(daemel_env_t *env, ir_node *node, ir_nodeset_t *nodeset)
+{
+ int i, arity;
+ const arch_register_class_t *cls = env->cls;
+ const arch_env_t *arch_env = env->arch_env;
+ const bitset_t *bitset = env->spilled_nodes;
+
+ /* You should better break out of your loop when hitting the first phi
+ * function. */
+ assert(!is_Phi(node) && "liveness_transfer produces invalid results for phi nodes");
+
+ if(arch_irn_consider_in_reg_alloc(arch_env, cls, node)) {
+ ir_nodeset_remove(nodeset, node);
+ }
+
+ arity = get_irn_arity(node);
+ for(i = 0; i < arity; ++i) {
+ ir_node *op = get_irn_n(node, i);
+
+ if(arch_irn_consider_in_reg_alloc(arch_env, cls, op)
+ && !bitset_is_set(bitset, get_irn_idx(op))) {
+ ir_nodeset_insert(nodeset, op);
+ }
+ }
+}
+
+/**
+ * make sure register pressure in a block is always equal or below the number
+ * of available registers
+ */
+static
+void spill_block(ir_node *block, void *data)
+{
+ daemel_env_t *env = data;
+ const arch_env_t *arch_env = env->arch_env;
+ const arch_register_class_t *cls = env->cls;
+ const be_lv_t *lv = env->lv;
+ ir_nodeset_t live_nodes;
+ ir_nodeset_iterator_t iter;
+ ir_node *node;
+ bitset_t *spilled_nodes = env->spilled_nodes;
+
+ DBG((dbg, LEVEL_1, "spilling block %+F\n", block));
+
+ ir_nodeset_init(&live_nodes);
+ be_liveness_end_of_block_ir_nodeset(lv, arch_env, cls, block, &live_nodes);
+
+ foreach_ir_nodeset(&live_nodes, node, iter) {
+ DBG((dbg, LEVEL_2, "\t%+F is live-in... ", node));
+ if(bitset_is_set(spilled_nodes, get_irn_idx(node))) {
+ DBG((dbg, LEVEL_2, "but spilled; removing.\n"));
+ } else {
+ DBG((dbg, LEVEL_2, "keeping.\n"));
+ }
+ }
+
+ sched_foreach_reverse(block, node) {
+ if(is_Phi(node))
+ break;
+
+ if(is_Proj(node) || be_is_Keep(node)) {
+ liveness_transfer(env, node, &live_nodes);
+ continue;
+ }
+
+ do_spilling(env, &live_nodes, node, NULL);
+
+ liveness_transfer(env, node, &live_nodes);
+ }
+
+ do_spilling(env, &live_nodes, node, block);
+
+ ir_nodeset_destroy(&live_nodes);
+}
+
+void be_spill_daemel(be_irg_t *birg, const arch_register_class_t *cls)
+{
+ daemel_env_t env;
+ ir_graph *irg = be_get_birg_irg(birg);
+ int n_regs = cls->n_regs - be_put_ignore_regs(birg, cls, NULL);
+
+ if(n_regs == 0)
+ return;
+
+ be_invalidate_liveness(birg);
+ be_assure_liveness(birg);
+
+ env.spill_env = be_new_spill_env(birg);
+ env.n_regs = n_regs;
+ env.arch_env = be_get_birg_arch_env(birg);
+ env.cls = cls;
+ env.lv = be_get_birg_liveness(birg);
+ env.spilled_nodes = bitset_malloc(get_irg_last_idx(irg));
+
+ irg_block_walk_graph(irg, spill_block, NULL, &env);
+
+ bitset_free(env.spilled_nodes);
+
+ be_insert_spills_reloads(env.spill_env);
+
+ be_delete_spill_env(env.spill_env);
+}
+
+void be_init_daemelspill(void)
+{
+ static be_spiller_t daemel_spiller = {
+ be_spill_daemel
+ };
+
+ be_register_spiller("daemel", &daemel_spiller);
+ FIRM_DBG_REGISTER(dbg, "ir.be.spilldaemel");
+}
+
+BE_REGISTER_MODULE_CONSTRUCTOR(be_init_doedelspill);
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