A small (very small) optimization
authorSebastian Hack <hack@ipd.info.uni-karlsruhe.de>
Fri, 5 Oct 2007 11:19:40 +0000 (11:19 +0000)
committerSebastian Hack <hack@ipd.info.uni-karlsruhe.de>
Fri, 5 Oct 2007 11:19:40 +0000 (11:19 +0000)
[r16097]

ir/be/bessaconstr.c
ir/be/bessaconstr.h

index d73bc7c..5498be6 100644 (file)
 
 DEBUG_ONLY(static firm_dbg_module_t *dbg = NULL;)
 
+static INLINE int is_inside(unsigned what, unsigned low, unsigned hi)
+{
+       return what - low < hi;
+}
+
 /**
  * Calculates the iterated dominance frontier of a set of blocks. Marks the
  * blocks as visited. Sets the link fields of the blocks in the dominance
  * frontier to the block itself.
  */
 static
-void mark_iterated_dominance_frontiers(const be_dom_front_info_t *domfronts,
-                                       waitq *worklist)
+void mark_iterated_dominance_frontiers(const be_ssa_construction_env_t *env)
 {
+       stat_ev_cnt_decl(blocks);
        DBG((dbg, LEVEL_3, "Dominance Frontier:"));
-       while(!pdeq_empty(worklist)) {
+       stat_ev_tim_push();
+       while (!pdeq_empty(env->worklist)) {
                int i;
-               ir_node *block = waitq_get(worklist);
-               ir_node **domfront = be_get_dominance_frontier(domfronts, block);
+               ir_node *block = waitq_get(env->worklist);
+               ir_node **domfront = be_get_dominance_frontier(env->domfronts, block);
                int domfront_len = ARR_LEN(domfront);
 
                for (i = 0; i < domfront_len; ++i) {
                        ir_node *y = domfront[i];
-                       if(Block_block_visited(y))
+                       if (Block_block_visited(y))
+                               continue;
+
+                       /*
+                        * It makes no sense to add phi-functions to blocks
+                        * that are not dominated by any definition;
+                        * all uses are dominated, hence the paths reaching the uses
+                        * have to stay in the dominance subtrees of the given definitions.
+                        */
+
+                       if (!is_inside(get_Block_dom_tree_pre_num(y), env->min_dom, env->max_dom))
                                continue;
 
-                       if(!irn_visited(y)) {
+                       if (!irn_visited(y)) {
                                set_irn_link(y, NULL);
-                               waitq_put(worklist, y);
+                               waitq_put(env->worklist, y);
                        }
+
                        DBG((dbg, LEVEL_3, " %+F", y));
                        mark_Block_block_visited(y);
+                       stat_ev_cnt_inc(blocks);
                }
        }
+       stat_ev_tim_pop("bessaconstr_idf_time");
+       stat_ev_cnt_done(blocks, "bessaconstr_idf_blocks");
        DBG((dbg, LEVEL_3, "\n"));
 }
 
@@ -160,7 +180,6 @@ ir_node *search_def_end_of_block(be_ssa_construction_env_t *env, ir_node *block)
                ir_node *def = get_def_at_idom(env, block);
                mark_irn_visited(block);
                set_irn_link(block, def);
-
                return def;
        }
 }
@@ -206,6 +225,16 @@ ir_node *search_def(be_ssa_construction_env_t *env, ir_node *at)
        return get_def_at_idom(env, block);
 }
 
+static
+void update_domzone(be_ssa_construction_env_t *env, const ir_node *bl)
+{
+       int start = get_Block_dom_tree_pre_num(bl);
+       int end   = get_Block_dom_max_subtree_pre_num(bl) + 1;
+
+       env->min_dom = MIN(env->min_dom, start);
+       env->max_dom = MAX(env->max_dom, end);
+}
+
 /**
  * Adds a definition into the link field of the block. The definitions are
  * sorted by dominance. A non-visited block means no definition has been
@@ -243,14 +272,24 @@ void introduce_def_at_block(ir_node *block, ir_node *def)
 void be_ssa_construction_init(be_ssa_construction_env_t *env, be_irg_t *birg)
 {
        ir_graph *irg = be_get_birg_irg(birg);
-       memset(env, 0, sizeof(env[0]));
+       ir_node *sb   = get_irg_start_block(irg);
+       int n_blocks  = get_Block_dom_max_subtree_pre_num(sb);
+
+       stat_ev_ctx_push_fobj("bessaconstr", irg);
+       stat_ev_tim_push();
 
+       (void) n_blocks;
+       stat_ev_dbl("bessaconstr_n_blocks", n_blocks);
+
+       memset(env, 0, sizeof(env[0]));
        be_assure_dom_front(birg);
 
        env->irg       = irg;
        env->domfronts = be_get_birg_dom_front(birg);
        env->new_phis  = NEW_ARR_F(ir_node*, 0);
        env->worklist  = new_waitq();
+       env->min_dom   = INT_MAX;
+       env->max_dom   = 0;
 
        set_using_visited(irg);
        set_using_block_visited(irg);
@@ -266,12 +305,16 @@ void be_ssa_construction_init(be_ssa_construction_env_t *env, be_irg_t *birg)
 
 void be_ssa_construction_destroy(be_ssa_construction_env_t *env)
 {
+       stat_ev_int("bessaconstr_phis", ARR_LEN(env->new_phis));
        del_waitq(env->worklist);
        DEL_ARR_F(env->new_phis);
 
        clear_using_visited(env->irg);
        clear_using_block_visited(env->irg);
        clear_using_irn_link(env->irg);
+
+       stat_ev_tim_pop("bessaconstr_total_time");
+       stat_ev_ctx_pop("bessaconstr");
 }
 
 void be_ssa_construction_add_copy(be_ssa_construction_env_t *env,
@@ -293,6 +336,7 @@ void be_ssa_construction_add_copy(be_ssa_construction_env_t *env,
                waitq_put(env->worklist, block);
        }
        introduce_def_at_block(block, copy);
+       update_domzone(env, block);
 }
 
 void be_ssa_construction_add_copies(be_ssa_construction_env_t *env,
@@ -315,6 +359,7 @@ void be_ssa_construction_add_copies(be_ssa_construction_env_t *env,
                        waitq_put(env->worklist, block);
                }
                introduce_def_at_block(block, copy);
+               update_domzone(env, block);
        }
 }
 
@@ -329,59 +374,65 @@ ir_node **be_ssa_construction_get_new_phis(be_ssa_construction_env_t *env)
        return env->new_phis;
 }
 
-void be_ssa_construction_fix_users(be_ssa_construction_env_t *env,
-                                   ir_node *value)
+void be_ssa_construction_fix_users_array(be_ssa_construction_env_t *env,
+                                         ir_node **nodes, size_t nodes_len)
 {
+       stat_ev_cnt_decl(uses);
        const ir_edge_t *edge, *next;
+       size_t i;
 
        if(!env->iterated_domfront_calculated) {
-               mark_iterated_dominance_frontiers(env->domfronts, env->worklist);
+               mark_iterated_dominance_frontiers(env);
                env->iterated_domfront_calculated = 1;
        }
 
-       /*
-        * Search the valid def for each use and set it.
-        */
-       foreach_out_edge_safe(value, edge, next) {
-               ir_node *use = get_edge_src_irn(edge);
-               ir_node *at  = use;
-               int pos      = get_edge_src_pos(edge);
-               ir_node *def;
-
-               if(env->ignore_uses != NULL     &&
-                  ir_nodeset_contains(env->ignore_uses, use))
-                       continue;
-               if(is_Anchor(use))
-                       continue;
-
-               if(is_Phi(use)) {
-                       ir_node *block = get_nodes_block(use);
-                       ir_node *predblock = get_Block_cfgpred_block(block, pos);
-                       at = sched_last(predblock);
-               }
+       stat_ev_int("bessaconstr_domzone", env->max_dom - env->min_dom);
+       stat_ev_tim_push();
+       for(i = 0; i < nodes_len; ++i) {
+               ir_node *value = nodes[i];
+
+               /*
+                * Search the valid def for each use and set it.
+                */
+               foreach_out_edge_safe(value, edge, next) {
+                       ir_node *use = get_edge_src_irn(edge);
+                       ir_node *at  = use;
+                       int pos      = get_edge_src_pos(edge);
+                       ir_node *def;
+
+                       if(env->ignore_uses != NULL     &&
+                          ir_nodeset_contains(env->ignore_uses, use))
+                               continue;
+                       if(is_Anchor(use))
+                               continue;
 
-               def = search_def(env, at);
+                       if(is_Phi(use)) {
+                               ir_node *block = get_nodes_block(use);
+                               ir_node *predblock = get_Block_cfgpred_block(block, pos);
+                               at = sched_last(predblock);
+                       }
 
-               if(def == NULL) {
-                       panic("no definition found for %+F at position %d\n", use, pos);
-               }
+                       def = search_def(env, at);
 
-               DBG((dbg, LEVEL_2, "\t%+F(%d) -> %+F\n", use, pos, def));
-               set_irn_n(use, pos, def);
+                       if(def == NULL) {
+                               panic("no definition found for %+F at position %d\n", use, pos);
+                       }
+
+                       DBG((dbg, LEVEL_2, "\t%+F(%d) -> %+F\n", use, pos, def));
+                       set_irn_n(use, pos, def);
+                       stat_ev_cnt_inc(uses);
+               }
        }
+       stat_ev_tim_pop("bessaconstr_fix_time");
+       stat_ev_cnt_done(uses, "bessaconstr_uses");
 }
 
-void be_ssa_construction_fix_users_array(be_ssa_construction_env_t *env,
-                                         ir_node **nodes, size_t nodes_len)
+void be_ssa_construction_fix_users(be_ssa_construction_env_t *env, ir_node *value)
 {
-       size_t i;
-
-       for(i = 0; i < nodes_len; ++i) {
-               ir_node *node = nodes[i];
-               be_ssa_construction_fix_users(env, node);
-       }
+       be_ssa_construction_fix_users_array(env, &value, 1);
 }
 
+
 void be_ssa_construction_update_liveness_phis(be_ssa_construction_env_t *env,
                                               be_lv_t *lv)
 {
index c8d77f3..4070298 100644 (file)
@@ -53,6 +53,7 @@
 #include "bedomfront.h"
 #include "irnodeset.h"
 #include "belive.h"
+#include "bitset.h"
 #include "beirg.h"
 #include "pdeq.h"
 
@@ -64,6 +65,8 @@ typedef struct be_ssa_construction_env_t {
        const ir_nodeset_t        *ignore_uses;
        ir_node                   **new_phis;
        int                       iterated_domfront_calculated;
+       int                       min_dom;
+       int                       max_dom;
 } be_ssa_construction_env_t;
 
 /**