-/**
- * @file beuse.c
- * @date 27.06.2005
- * @author Sebastian Hack, Matthias Braun
+/*
+ * Copyright (C) 1995-2011 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.
*
- * Methods to compute when a value will be used again.
+ * Licensees holding valid libFirm Professional Edition licenses may use
+ * this file in accordance with the libFirm Commercial License.
+ * Agreement provided with the Software.
*
- * Copyright (C) 2005 Universitaet Karlsruhe
- * Released under the GPL
+ * 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 Methods to compute when a value will be used again.
+ * @author Sebastian Hack, Matthias Braun
+ * @date 27.06.2005
*/
-#ifdef HAVE_CONFIG_H
#include "config.h"
-#endif
#include <limits.h>
#include <stdlib.h>
#include "irgraph_t.h"
#include "iredges_t.h"
#include "irdom_t.h"
+#include "util.h"
#include "be_t.h"
#include "beutil.h"
#include "belive_t.h"
-#include "benode_t.h"
-#include "besched_t.h"
+#include "benode.h"
+#include "besched.h"
#include "beirgmod.h"
#include "bearch.h"
-#include "beuses_t.h"
-#include "benodesets.h"
+#include "beuses.h"
-#define SCAN_INTERBLOCK_USES
+#define UNKNOWN_OUTERMOST_LOOP ((unsigned)-1)
-typedef struct _be_use_t {
+typedef struct be_use_t {
const ir_node *block;
const ir_node *node;
+ unsigned outermost_loop;
unsigned next_use;
+ ir_visited_t visited;
} be_use_t;
-struct _be_uses_t {
- set *uses;
- ir_graph *irg;
- const ir_exec_freq *execfreqs;
- const be_lv_t *lv;
- DEBUG_ONLY(firm_dbg_module_t *dbg;)
+/**
+ * The "uses" environment.
+ */
+struct be_uses_t {
+ set *uses; /**< cache: contains all computed uses so far. */
+ ir_graph *irg; /**< the graph for this environment. */
+ const be_lv_t *lv; /**< the liveness for the graph. */
+ ir_visited_t visited_counter; /**< current search counter. */
+ DEBUG_ONLY(firm_dbg_module_t *dbg; /**< debug module for debug messages. */)
};
+/**
+ * Set-compare two uses.
+ */
static int cmp_use(const void *a, const void *b, size_t n)
{
- const be_use_t *p = a;
- const be_use_t *q = b;
+ const be_use_t *p = (const be_use_t*)a;
+ const be_use_t *q = (const be_use_t*)b;
+ (void) n;
+
return !(p->block == q->block && p->node == q->node);
}
-static const be_use_t *get_or_set_use_block(be_uses_t *uses,
+static be_next_use_t get_next_use(be_uses_t *env, ir_node *from,
+ const ir_node *def, int skip_from_uses);
+
+/**
+ * Return the use for the given definition in the given block if exists,
+ * else create it.
+ *
+ * @param env the uses environment
+ * @param block the block we search the use in
+ * @param def the definition of the value we are searching
+ */
+static const be_use_t *get_or_set_use_block(be_uses_t *env,
const ir_node *block,
const ir_node *def)
{
- unsigned hash = HASH_COMBINE(nodeset_hash(block), nodeset_hash(def));
+ unsigned hash = hash_combine(hash_irn(block), hash_irn(def));
be_use_t temp;
be_use_t* result;
temp.block = block;
temp.node = def;
- result = set_find(uses->uses, &temp, sizeof(temp), hash);
+ result = set_find(be_use_t, env->uses, &temp, sizeof(temp), hash);
- if(result == NULL) {
+ if (result == NULL) {
// insert templ first as we might end in a loop in the get_next_use
// call otherwise
temp.next_use = USES_INFINITY;
- result = set_insert(uses->uses, &temp, sizeof(temp), hash);
+ temp.outermost_loop = UNKNOWN_OUTERMOST_LOOP;
+ temp.visited = 0;
+ result = set_insert(be_use_t, env->uses, &temp, sizeof(temp), hash);
+ }
+
+ if (result->outermost_loop == UNKNOWN_OUTERMOST_LOOP && result->visited < env->visited_counter) {
+ be_next_use_t next_use;
- result->next_use = be_get_next_use(uses, sched_first(block), 0, def, 0);
+ result->visited = env->visited_counter;
+ next_use = get_next_use(env, sched_first(block), def, 0);
+ if (next_use.outermost_loop != UNKNOWN_OUTERMOST_LOOP) {
+ result->next_use = next_use.time;
+ result->outermost_loop = next_use.outermost_loop;
+ DBG((env->dbg, LEVEL_5, "Setting nextuse of %+F in block %+F to %u (outermostloop %d)\n",
+ def, block, result->next_use, result->outermost_loop));
+ }
}
return result;
}
-unsigned be_get_next_use(be_uses_t *uses, const ir_node *from,
- unsigned from_step, const ir_node *def,
- int skip_from_uses)
+/**
+ * Check if a value of the given definition is used in the given block
+ * as a Phi argument.
+ *
+ * @param block the block to check
+ * @param def the definition of the value
+ *
+ * @return non-zero if the value is used in the given block as a Phi argument
+ * in one of its successor blocks.
+ */
+static int be_is_phi_argument(const ir_node *block, const ir_node *def)
{
- unsigned step = from_step;
- ir_node *block = get_nodes_block(from);
- const ir_node *node;
- const ir_edge_t *edge;
+#if 1
+ if (get_irn_n_edges_kind(block, EDGE_KIND_BLOCK) < 1)
+#else
+ if (get_irn_n_edges_kind(block, EDGE_KIND_BLOCK) != 1)
+#endif
+ return 0;
- if(skip_from_uses) {
- step++;
- from = sched_next(from);
+ ir_node *const succ_block = get_first_block_succ(block);
+
+ if (get_Block_n_cfgpreds(succ_block) <= 1) {
+ /* no Phis in the successor */
+ return 0;
}
- sched_foreach_from(from, node) {
- int i, arity;
+ /* find the index of block in its successor */
+ int const i = get_Block_cfgpred_pos(succ_block, block);
+ assert(i >= 0);
- arity = get_irn_arity(node);
- for (i = 0; i < arity; ++i) {
- const ir_node *operand = get_irn_n(node, i);
+ /* iterate over the Phi nodes in the successor and check if def is
+ * one of its arguments */
+ sched_foreach(succ_block, node) {
+ ir_node *arg;
- if (operand == def) {
- DBG((uses->dbg, LEVEL_3, "found use of %+F at %+F\n", operand, node));
- return step;
- }
+ if (!is_Phi(node)) {
+ /* found first non-Phi node, we can stop the search here */
+ break;
}
- step++;
+ arg = get_irn_n(node, i);
+ if (arg == def)
+ return 1;
}
- if(be_is_live_end(uses->lv, block, def))
- return step;
+ return 0;
+}
-#ifdef SCAN_INTERBLOCK_USES
- {
- double best_execfreq = -1;
- unsigned next_use = USES_INFINITY;
+/**
+ * Retrieve the scheduled index (the "step") of this node in its
+ * block.
+ *
+ * @param node the node
+ */
+static inline unsigned get_step(const ir_node *node)
+{
+ return (unsigned)PTR_TO_INT(get_irn_link(node));
+}
+
+/**
+ * Set the scheduled index (the "step") of this node in its
+ * block.
+ *
+ * @param node the node
+ * @param step the scheduled index of the node
+ */
+static inline void set_step(ir_node *node, unsigned step)
+{
+ set_irn_link(node, INT_TO_PTR(step));
+}
+
+/**
+ * Find the next use of a value defined by def, starting at node from.
+ *
+ * @param env the uses environment
+ * @param from the node at which we should start the search
+ * @param def the definition of the value
+ * @param skip_from_uses if non-zero, ignore from uses
+ */
+static be_next_use_t get_next_use(be_uses_t *env, ir_node *from,
+ const ir_node *def, int skip_from_uses)
+{
+ unsigned step;
+ ir_node *block = get_nodes_block(from);
+ ir_node *next_use_node;
+ ir_node *node;
+ unsigned timestep;
+ unsigned next_use_step;
+
+ assert(skip_from_uses == 0 || skip_from_uses == 1);
+ if (skip_from_uses) {
+ from = sched_next(from);
+ }
+ next_use_node = NULL;
+ next_use_step = INT_MAX;
+ timestep = get_step(from);
+ foreach_out_edge(def, edge) {
+ unsigned node_step;
+ node = get_edge_src_irn(edge);
+
+ if (is_Anchor(node))
+ continue;
+ if (get_nodes_block(node) != block)
+ continue;
+ if (is_Phi(node))
+ continue;
+
+ node_step = get_step(node);
+ if (node_step < timestep)
+ continue;
+ if (node_step < next_use_step) {
+ next_use_node = node;
+ next_use_step = node_step;
+ }
+ }
+
+ if (next_use_node != NULL) {
+ be_next_use_t result;
+ result.time = next_use_step - timestep + skip_from_uses;
+ result.outermost_loop = get_loop_depth(get_irn_loop(block));
+ result.before = next_use_node;
+ return result;
+ }
+
+ node = sched_last(block);
+ step = get_step(node) + 1 + timestep + skip_from_uses;
+
+ if (be_is_phi_argument(block, def)) {
+ // TODO we really should continue searching the uses of the phi,
+ // as a phi isn't a real use that implies a reload (because we could
+ // easily spill the whole phi)
+
+ be_next_use_t result;
+ result.time = step;
+ result.outermost_loop = get_loop_depth(get_irn_loop(block));
+ result.before = block;
+ return result;
+ }
+
+ {
+ unsigned next_use = USES_INFINITY;
+ unsigned outermost_loop;
+ be_next_use_t result;
+ ir_loop *loop = get_irn_loop(block);
+ unsigned loopdepth = get_loop_depth(loop);
+ int found_visited = 0;
+ int found_use = 0;
+ ir_graph *irg = get_irn_irg(block);
+ ir_node *startblock = get_irg_start_block(irg);
+
+ result.before = NULL;
+ outermost_loop = loopdepth;
foreach_block_succ(block, edge) {
const be_use_t *use;
const ir_node *succ_block = get_edge_src_irn(edge);
- double execfreq = get_block_execfreq(uses->execfreqs, succ_block);
+ ir_loop *succ_loop;
+ unsigned use_dist;
- //execfreq_sum += execfreq;
+ if (succ_block == startblock)
+ continue;
- if(execfreq > best_execfreq) {
- best_execfreq = execfreq;
+ DBG((env->dbg, LEVEL_5, "Checking succ of block %+F: %+F (for use of %+F)\n", block, succ_block, def));
+ if (!be_is_live_in(env->lv, succ_block, def)) {
+ //next_use = USES_INFINITY;
+ DBG((env->dbg, LEVEL_5, " not live in\n"));
+ continue;
+ }
- if(!be_is_live_in(uses->lv, succ_block, def)) {
- next_use = USES_INFINITY;
- continue;
+ use = get_or_set_use_block(env, succ_block, def);
+ DBG((env->dbg, LEVEL_5, "Found %u (loopdepth %u) (we're in block %+F)\n", use->next_use,
+ use->outermost_loop, block));
+ if (USES_IS_INFINITE(use->next_use)) {
+ if (use->outermost_loop == UNKNOWN_OUTERMOST_LOOP) {
+ found_visited = 1;
}
+ continue;
+ }
- use = get_or_set_use_block(uses, succ_block, def);
- //if(USES_IS_INFINITE(use->next_use))
- // continue;
+ found_use = 1;
+ use_dist = use->next_use;
- next_use = use->next_use;
+ succ_loop = get_irn_loop(succ_block);
+ if (get_loop_depth(succ_loop) < loopdepth) {
+ unsigned factor = (loopdepth - get_loop_depth(succ_loop)) * 5000;
+ DBG((env->dbg, LEVEL_5, "Increase usestep because of loop out edge %d -> %d (%u)\n", factor));
+ // TODO we should use the number of nodes in the loop or so...
+ use_dist += factor;
}
- //next_use += use->next_use / execfreq;
+ if (use_dist < next_use) {
+ next_use = use_dist;
+ outermost_loop = use->outermost_loop;
+ result.before = use->node;
+ }
}
- /*if(next_use == 0)
- return USES_INFINITY;*/
+ if (loopdepth < outermost_loop)
+ outermost_loop = loopdepth;
- //next_use /= execfreq_sum;
+ result.time = next_use + step;
+ result.outermost_loop = outermost_loop;
- return ((unsigned) next_use) + step;
+ if (!found_use && found_visited) {
+ // the current result is correct for the current search, but isn't
+ // generally correct, so mark it
+ result.outermost_loop = UNKNOWN_OUTERMOST_LOOP;
+ }
+ DBG((env->dbg, LEVEL_5, "Result: %d (outerloop: %u)\n", result.time, result.outermost_loop));
+ return result;
}
-#else
- return USES_INFINITY;
-#endif
}
-be_uses_t *be_begin_uses(ir_graph *irg, const ir_exec_freq *execfreqs, const be_lv_t *lv)
+be_next_use_t be_get_next_use(be_uses_t *env, ir_node *from,
+ const ir_node *def, int skip_from_uses)
{
- be_uses_t *uses = xmalloc(sizeof(uses[0]));
+ ++env->visited_counter;
+ return get_next_use(env, from, def, skip_from_uses);
+}
+
+/**
+ * Pre-block walker, set the step number for every scheduled node
+ * in increasing order.
+ *
+ * After this, two scheduled nodes can be easily compared for the
+ * "scheduled earlier in block" property.
+ */
+static void set_sched_step_walker(ir_node *block, void *data)
+{
+ unsigned step = 0;
+ (void) data;
+
+ sched_foreach(block, node) {
+ set_step(node, step);
+ if (is_Phi(node))
+ continue;
+ ++step;
+ }
+}
+
+be_uses_t *be_begin_uses(ir_graph *irg, const be_lv_t *lv)
+{
+ be_uses_t *env = XMALLOC(be_uses_t);
+
+ assure_edges(irg);
+
+ //set_using_irn_link(irg);
- edges_assure(irg);
+ /* precalculate sched steps */
+ irg_block_walk_graph(irg, set_sched_step_walker, NULL, NULL);
- uses->uses = new_set(cmp_use, 512);
- uses->irg = irg;
- uses->execfreqs = execfreqs;
- uses->lv = lv;
- FIRM_DBG_REGISTER(uses->dbg, "firm.be.uses");
+ env->uses = new_set(cmp_use, 512);
+ env->irg = irg;
+ env->lv = lv;
+ env->visited_counter = 0;
+ FIRM_DBG_REGISTER(env->dbg, "firm.be.uses");
- return uses;
+ return env;
}
-void be_end_uses(be_uses_t *uses)
+void be_end_uses(be_uses_t *env)
{
- del_set(uses->uses);
- free(uses);
+ //clear_using_irn_link(env->irg);
+ del_set(env->uses);
+ free(env);
}
projects / libfirm / blobdiff