rename set_using_visited to set_using_irn_visited, some cosmetics, remove obsolete...
[libfirm] / ir / be / beuses.c
index 36f586d..b3261d3 100644 (file)
@@ -1,12 +1,28 @@
-/**
- * @file   beuse.c
- * @date   27.06.2005
- * @author Sebastian Hack, Matthias Braun
+/*
+ * Copyright (C) 1995-2008 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
+ * @version     $Id$
  */
 #ifdef HAVE_CONFIG_H
 #include "config.h"
 #include "benode_t.h"
 #include "besched_t.h"
 #include "beirgmod.h"
-#include "bearch.h"
-#include "beuses_t.h"
-#include "benodesets.h"
+#include "bearch_t.h"
+#include "beuses.h"
 
 #define SCAN_INTERBLOCK_USES
 
 typedef struct _be_use_t {
        const ir_node *block;
        const ir_node *node;
+       int outermost_loop;
        unsigned next_use;
+       unsigned visited;
 } be_use_t;
 
 struct _be_uses_t {
        set *uses;
        ir_graph *irg;
-       const ir_exec_freq *execfreqs;
        const be_lv_t *lv;
+       unsigned visited_counter;
        DEBUG_ONLY(firm_dbg_module_t *dbg;)
 };
 
@@ -57,146 +74,329 @@ 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;
+       (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,
+                                                                 unsigned from_step, const ir_node *def,
+                                                                 int skip_from_uses);
+
+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(env->uses, &temp, sizeof(temp), hash);
 
        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 = -1;
+               temp.visited = 0;
+               result = set_insert(env->uses, &temp, sizeof(temp), hash);
+       }
 
-               result->next_use = be_get_next_use(uses, sched_first(block), 0, def, 0);
+       if(result->outermost_loop < 0 && result->visited < env->visited_counter) {
+               be_next_use_t next_use;
+
+               result->visited = env->visited_counter;
+               next_use = get_next_use(env, sched_first(block), 0, def, 0);
+               if(next_use.outermost_loop >= 0) {
+                       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;
 }
 
-static int is_real_use(const ir_node *node)
+static int be_is_phi_argument(const ir_node *block, const ir_node *def)
 {
-       if(be_is_Spill(node))
+       ir_node *node;
+       ir_node *succ_block = NULL;
+       const ir_edge_t *edge;
+       int arity, i;
+
+#if 0
+       if(get_irn_n_edges_kind(block, EDGE_KIND_BLOCK) > 1)
                return 0;
-       /* we don't check for phi loops yet, so don't enable this
-       if(is_Phi(node))
+#endif
+
+       foreach_block_succ(block, edge) {
+               succ_block = get_edge_src_irn(edge);
+               break;
+       }
+
+       arity = get_Block_n_cfgpreds(succ_block);
+       if(arity <= 1)
                return 0;
-       */
 
-       return 1;
+       for(i = 0; i < arity; ++i) {
+               if(get_Block_cfgpred_block(succ_block, i) == block)
+                       break;
+       }
+       assert(i < arity);
+
+       sched_foreach(succ_block, node) {
+               ir_node *arg;
+
+               if(!is_Phi(node))
+                       break;
+
+               arg = get_irn_n(node, i);
+               if(arg == def)
+                       return 1;
+       }
+
+       return 0;
 }
 
-unsigned be_get_next_use(be_uses_t *uses, const ir_node *from,
-                         unsigned from_step, const ir_node *def,
-                         int skip_from_uses)
+static INLINE
+unsigned get_step(const ir_node *node)
 {
-       unsigned step = from_step;
-       ir_node *block = get_nodes_block(from);
-       const ir_node *node;
+       return PTR_TO_INT(get_irn_link(node));
+}
+
+static be_next_use_t get_next_use(be_uses_t *env, ir_node *from,
+                                                                 unsigned from_step, const ir_node *def,
+                                                                 int skip_from_uses)
+{
+       unsigned  step  = from_step;
+       ir_node  *block = get_nodes_block(from);
+       ir_node  *next_use;
+       ir_node  *node;
+       unsigned  timestep;
+       unsigned  next_use_step;
        const ir_edge_t *edge;
 
+#if 1
+       assert(skip_from_uses == 0 || skip_from_uses == 1);
        if(skip_from_uses) {
-               step++;
                from = sched_next(from);
        }
 
+       next_use      = NULL;
+       next_use_step = INT_MAX;
+       timestep      = get_step(from);
+       foreach_out_edge(def, edge) {
+               ir_node  *node = get_edge_src_irn(edge);
+               unsigned  node_step;
+
+               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;
+                       next_use_step = node_step;
+               }
+       }
+
+       if(next_use != 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;
+               return result;
+       }
+
+       node = sched_last(block);
+       step = get_step(node) + 1 + timestep + skip_from_uses;
+
+#else
+       if(skip_from_uses) {
+               from = sched_next(from);
+               ++step;
+       }
+
        sched_foreach_from(from, node) {
                int i, arity;
 
+               if(is_Phi(node)) {
+                       step++;
+                       continue;
+               }
+
                arity = get_irn_arity(node);
                for (i = 0; i < arity; ++i) {
                        const ir_node *operand = get_irn_n(node, i);
 
                        if (operand == def) {
-                               DBG((uses->dbg, LEVEL_3, "found use of %+F at %+F\n", operand, node));
+                               be_next_use_t result;
+
+                               DBG((env->dbg, LEVEL_3, "found use of %+F at %+F\n", operand, node));
 
-                               if(!is_real_use(node)) {
-                                       return be_get_next_use(uses, node, step, node, 1);
-                               } else {
-                                       return step;
+                               /**
+                                * Spills/Reloads are a special case, they're not really a
+                                * usage of a value, continue searching
+                                */
+                               if (be_is_Spill(node) || be_is_Reload(node)) {
+                                       return be_get_next_use(env, node, step, node, 1);
                                }
+
+                               result.time           = step;
+                               result.outermost_loop = get_loop_depth(get_irn_loop(block));
+                               result.before         = node;
+                               return result;
                        }
                }
 
                step++;
        }
+#endif
 
-       if(be_is_live_end(uses->lv, block, def)) {
+       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)
-               return step;
+
+               be_next_use_t result;
+               result.time           = step;
+               result.outermost_loop = get_loop_depth(get_irn_loop(block));
+               result.before         = block;
+               return result;
        }
 
 #ifdef SCAN_INTERBLOCK_USES
        {
-       double best_execfreq = -1;
-       unsigned next_use = USES_INFINITY;
-
+       unsigned next_use   = USES_INFINITY;
+       int outermost_loop;
+       be_next_use_t result;
+       ir_loop *loop       = get_irn_loop(block);
+       int 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 %d) (we're in block %+F)\n", use->next_use,
+                                       use->outermost_loop, block));
+               if(USES_IS_INFINITE(use->next_use)) {
+                       if(use->outermost_loop < 0) {
+                               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 = -1;
+       }
+       DBG((env->dbg, LEVEL_5, "Result: %d (outerloop: %d)\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,
+                         unsigned from_step, const ir_node *def,
+                         int skip_from_uses)
+{
+       env->visited_counter++;
+       return get_next_use(env, from, from_step, def, skip_from_uses);
+}
+
+static
+void set_sched_step_walker(ir_node *block, void *data)
+{
+       ir_node  *node;
+       unsigned step = 0;
+       (void) data;
+
+       sched_foreach(block, node) {
+               set_irn_link(node, INT_TO_PTR(step));
+               if(is_Phi(node))
+                       continue;
+               if(is_Proj(node))
+                       continue;
+               ++step;
+       }
+}
+
+be_uses_t *be_begin_uses(ir_graph *irg, const be_lv_t *lv)
 {
-       be_uses_t *uses = xmalloc(sizeof(uses[0]));
+       be_uses_t *env = xmalloc(sizeof(env[0]));
 
        edges_assure(irg);
 
-       uses->uses = new_set(cmp_use, 512);
-       uses->irg = irg;
-       uses->execfreqs = execfreqs;
-       uses->lv = lv;
-       FIRM_DBG_REGISTER(uses->dbg, "firm.be.uses");
+       //set_using_irn_link(irg);
+
+       /* precalculate sched steps */
+       irg_block_walk_graph(irg, set_sched_step_walker, NULL, NULL);
+
+       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);
 }