+++ /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 Naive spilling algorithm
- * @author Matthias Braun
- * @date 20.09.2005
- * @version $Id$
- * @summary
- * This implements a naive 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;
- 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_liveness_assure_sets(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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