X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Fana%2Fexecution_frequency.c;h=d95f84496e8a294683d140f5b6e23f291421db00;hb=7e8388fa7996ff182d3aa4e0cdd41b27bed4982f;hp=08e845cd21a4fa7ec1c3d7008f5eec9d6e642d10;hpb=2c6a8fa3e3be84a942fdf9c7f385f61e0f913110;p=libfirm

diff --git a/ir/ana/execution_frequency.c b/ir/ana/execution_frequency.c
index 08e845cd2..d95f84496 100644
--- a/ir/ana/execution_frequency.c
+++ b/ir/ana/execution_frequency.c
@@ -1,13 +1,28 @@
 /*
- * Project:     libFIRM
- * File name:   ir/ana/execution_frequency.c
- * Purpose:     Compute an estimate of basic block executions.
- * Author:      Goetz Lindenmaier
- * Modified by:
- * Created:     5.11.2004
- * CVS-ID:      $Id$
- * Copyright:   (c) 2004 Universität Karlsruhe
- * Licence:     This file protected by GPL -  GNU GENERAL PUBLIC LICENSE.
+ * 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.
+ *
+ * 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     Compute an estimate of basic block executions.
+ * @author    Goetz Lindenmaier
+ * @date      5.11.2004
+ * @version   $Id$
  */
 #ifdef HAVE_CONFIG_H
 #include "config.h"
@@ -18,12 +33,18 @@
 #include "firm_common_t.h"
 #include "set.h"
 #include "pdeq.h"
+#include "hashptr.h"
 
-#include "irprog.h"
+#include "irprog_t.h"
+#include "irgraph_t.h"
+#include "irnode_t.h"
 #include "irloop.h"
+#include "irgwalk.h"
 
 #include "interval_analysis.h"
 
+void set_irp_exec_freq_state(exec_freq_state s);
+
 /*------------------------------------------------------------------*/
 /* A hashmap mapping the frequency to block and loop nodes.  Block
  * and loop nodes are regions.                                      */
@@ -32,6 +53,7 @@
 typedef struct {
   void   *reg;
   double  freq;
+  int     prob;
 } reg_exec_freq;
 
 /* We use this set for all nodes in all irgraphs. */
@@ -40,12 +62,13 @@ static set *exec_freq_set = NULL;
 static int exec_freq_cmp(const void *e1, const void *e2, size_t size) {
   reg_exec_freq *ef1 = (reg_exec_freq *)e1;
   reg_exec_freq *ef2 = (reg_exec_freq *)e2;
+  (void) size;
+
   return (ef1->reg != ef2->reg);
 }
 
-static INLINE unsigned int exec_freq_hash(void *e) {
-  unsigned int v = (unsigned int) ((reg_exec_freq *)e)->reg;
-  return v ^ (v>>8);
+static INLINE unsigned int exec_freq_hash(reg_exec_freq *e) {
+  return HASH_PTR(e->reg);
 }
 
 static INLINE void set_region_exec_freq(void *reg, double freq) {
@@ -55,13 +78,18 @@ static INLINE void set_region_exec_freq(void *reg, double freq) {
   set_insert(exec_freq_set, &ef, sizeof(ef), exec_freq_hash(&ef));
 }
 
-INLINE double get_region_exec_freq(void *reg) {
+double get_region_exec_freq(void *reg) {
   reg_exec_freq ef, *found;
   ef.reg  = reg;
+  assert(exec_freq_set);
 
   found = set_find(exec_freq_set, &ef, sizeof(ef), exec_freq_hash(&ef));
-  assert(found);
-  return found->freq;
+
+  /* Not found if information is invalid. */
+  if (found)
+    return found->freq;
+  else
+    return 0;
 }
 
 /* Returns the number of times the block is executed. */
@@ -76,7 +104,189 @@ double get_irn_exec_freq(ir_node *n) {
 
 
 /*------------------------------------------------------------------*/
-/* The algorithm to compute the execution freqencies.
+/* A algorithm that precomputes whether Conds lead to an exception.
+ * Computes a field for all Projs from Conds that says the following:
+ *   - The Proj projs from a normal dual Cond with probability 50:50
+ *   - This Proj of the Cond leads to an exception, i.e., a raise node.
+ *     It is taken with exception probability.
+ *   - The Proj of the Cond avoids an exception.  It is taken with
+ *     1 - exception probability.                                   */
+/*------------------------------------------------------------------*/
+
+#include "irouts.h"
+
+typedef enum {
+  Cond_prob_none,
+  Cond_prob_normal,
+  Cond_prob_avoid_exception,
+  Cond_prob_exception_taken,
+  Cond_prob_was_exception_taken,
+} Cond_prob;
+
+static int just_passed_a_Raise = 0;
+static ir_node *Cond_list = NULL;
+
+/* We do not use an extra set, as Projs are not yet in the existing one. */
+void set_ProjX_probability(ir_node *n, Cond_prob prob) {
+  reg_exec_freq ef;
+  ef.reg  = n;
+  ef.prob = prob;
+  set_insert(exec_freq_set, &ef, sizeof(ef), exec_freq_hash(&ef));
+}
+
+Cond_prob get_ProjX_probability(ir_node *n) {
+  reg_exec_freq ef, *found;
+  ef.reg  = n;
+
+  found = set_find(exec_freq_set, &ef, sizeof(ef), exec_freq_hash(&ef));
+
+  if (found)
+    return (Cond_prob)found->prob;
+  else
+    return Cond_prob_none;
+}
+
+/* A walker that only visits the nodes we want to see. */
+
+static void
+my_irg_walk_2_both(ir_node *node, irg_walk_func *pre, irg_walk_func *post, void * env) {
+  int i;
+  set_irn_visited(node, current_ir_graph->visited);
+
+  pre(node, env);
+
+  if (node->op != op_Block) {
+    ir_node *pred;
+    if (node->op == op_Proj)
+      pred = get_irn_n(node, 0);
+    else
+      pred = get_irn_n(node, -1);
+    if (pred->visited < current_ir_graph->visited)
+      my_irg_walk_2_both(pred, pre, post, env);
+  }
+
+  else {  /* a Block */
+    for (i = get_irn_arity(node) - 1; i >= 0; --i) {
+      ir_node *pred = get_irn_n(node, i);
+      if (pred->visited < current_ir_graph->visited)
+        my_irg_walk_2_both(pred, pre, post, env);
+    }
+  }
+
+  if (node->op == op_End) {
+    for (i = get_irn_arity(node) - 1; i >= 0; --i) {
+      ir_node *pred = get_irn_n(node, i);
+      if ((pred->op == op_Block) && (pred->visited < current_ir_graph->visited))
+        my_irg_walk_2_both(pred, pre, post, env);
+    }
+  }
+
+  post(node, env);
+}
+static void my_irg_walk_current_graph(irg_walk_func *pre, irg_walk_func *post, void *env) {
+  inc_irg_visited(current_ir_graph);
+  my_irg_walk_2_both(get_irg_end(current_ir_graph), pre, post, env);
+}
+
+
+static void walk_pre(ir_node *n, void *env)
+{
+  (void) env;
+  if (get_irn_op(n) == op_Raise)
+    just_passed_a_Raise = 1;
+
+  if (   (get_irn_op(n) == op_Proj)
+      && (get_irn_op(get_Proj_pred(n)) == op_Cond)
+      && (just_passed_a_Raise)) {
+    ir_node *other_proj;
+    ir_node *c = get_Proj_pred(n);
+
+    /* If we already visited the other Proj, and it also leads to a Raise,
+       we are in the middle of something. Continue searching. */
+    assert(get_irn_n_outs(c) == 2 && "encountered a switch cond");
+    other_proj = get_irn_out(c, 0);
+    if (other_proj == n) other_proj = get_irn_out(c, 1);
+    if (get_ProjX_probability(other_proj) == Cond_prob_exception_taken) {
+      set_ProjX_probability(other_proj, Cond_prob_was_exception_taken);
+      /* Keep searching for the Proj, so keep just_passed_a_Raise. */
+    } else {
+      set_ProjX_probability(n, Cond_prob_exception_taken);
+      just_passed_a_Raise = 0;
+    }
+  }
+
+  if (get_irn_op(n) == op_Cond) {
+    set_irn_link(n, Cond_list);
+    Cond_list = n;
+  }
+}
+
+static void walk_post(ir_node *n, void *env)
+{
+  (void) env;
+  if (get_irn_op(n) == op_Raise)
+    just_passed_a_Raise = 0;
+
+  if (   (get_irn_op(n) == op_Proj)
+      && (get_irn_op(get_Proj_pred(n)) == op_Cond)
+      && ((get_ProjX_probability(n) == Cond_prob_exception_taken)    ||
+	  (get_ProjX_probability(n) == Cond_prob_was_exception_taken)   )) {
+    just_passed_a_Raise = 1;
+  }
+}
+
+/** Precompute which Conds test for an exception.
+ *
+ *  Operates on current_ir_graph. */
+void precompute_cond_evaluation(void) {
+  ir_node *c;
+
+  compute_irg_outs(current_ir_graph);
+
+  just_passed_a_Raise = 0;
+  Cond_list = NULL;
+  my_irg_walk_current_graph(walk_pre, walk_post, NULL);
+
+  for (c = Cond_list; c; c = get_irn_link(c)) {
+    ir_node *p0, *p1;
+
+    assert(get_irn_n_outs(c) == 2 && "encountered a switch cond");
+    p0 = get_irn_out(c, 0);
+    p1 = get_irn_out(c, 1);
+
+    /* both are exceptions */
+    if ((get_ProjX_probability(p0) == Cond_prob_exception_taken) &&
+        (get_ProjX_probability(p1) == Cond_prob_exception_taken)   ) {
+      assert(0 && "I tried to avoid these!");
+      /* It's a */
+      set_ProjX_probability(p0, Cond_prob_normal);
+      set_ProjX_probability(p1, Cond_prob_normal);
+    }
+
+    /* p0 is exception */
+    else if (get_ProjX_probability(p0) == Cond_prob_exception_taken) {
+      set_ProjX_probability(p1, Cond_prob_avoid_exception);
+    }
+
+    /* p1 is exception */
+    else if (get_ProjX_probability(p1) == Cond_prob_exception_taken) {
+      set_ProjX_probability(p0, Cond_prob_avoid_exception);
+    }
+
+    /* none is exception */
+    else {
+      set_ProjX_probability(p0, Cond_prob_normal);
+      set_ProjX_probability(p1, Cond_prob_normal);
+    }
+  }
+}
+
+int is_fragile_Proj(ir_node *n) {
+  return is_Proj(n) && (get_ProjX_probability(n) == Cond_prob_exception_taken);
+}
+
+/*------------------------------------------------------------------*/
+/* The algorithm to compute the execution frequencies.
  *
  * Walk the control flow loop tree which we consider the interval
  * tree.  Compute the execution for the lowest loop, add inner loops
@@ -86,25 +296,33 @@ double get_irn_exec_freq(ir_node *n) {
 
 static double exception_prob = 0.001;
 
-static INLINE int is_loop_head(ir_node *cond) {
-  return false;
+static INLINE int is_loop_head(ir_node *cond)
+{
+  (void) cond;
+  return 0;
 }
 
+/** Weight a single region in edge.
+ *
+ *  Given all outs of the predecessor region, we can compute the weight of
+ *  this single edge. */
 static INLINE double get_weighted_region_exec_freq(void *reg, int pos) {
-  void *pred_reg = get_region_in(reg, pos);
-  double res, full_freq = get_region_exec_freq(pred_reg);
-  int n_outs     = get_region_n_outs    (pred_reg);
-  int n_exc_outs = get_region_n_exc_outs(pred_reg);
+  void *pred_reg        = get_region_in(reg, pos);
+  double res, full_freq = get_region_exec_freq (pred_reg);
+  int n_outs            = get_region_n_outs    (pred_reg);
+  int n_exc_outs        = get_region_n_exc_outs(pred_reg);
 
   ir_node *cfop;
   if (is_ir_node(reg)) {
-    cfop = skip_Proj(get_Block_cfgpred((ir_node *)reg, pos));
+    cfop = get_Block_cfgpred((ir_node *)reg, pos);
+    if (is_Proj(cfop) && (get_irn_op(get_Proj_pred(cfop)) != op_Cond))
+      cfop = skip_Proj(cfop);
   } else {
     assert(is_ir_loop(reg));
     cfop = get_loop_cfop(reg, pos);
   }
 
-  if (is_fragile_op(cfop)) {
+  if (is_fragile_op(cfop) || is_fragile_Proj(cfop)) {
     res = full_freq * exception_prob;
   } else {
 
@@ -135,8 +353,10 @@ static INLINE void compute_region_freqency(void *reg, double head_weight) {
   set_region_exec_freq(reg, my_freq);
 }
 
-static void check_proper_head(ir_loop *l, void *reg) {
+static void check_proper_head(ir_loop *l, void *reg)
+{
   int i, n_ins = get_region_n_ins(reg);
+  (void) l;
   for (i = 0; i < n_ins; ++i) {
     assert(!get_region_in(reg, i));
   }
@@ -155,7 +375,7 @@ static void compute_frequency(int default_loop_weight) {
     ir_loop *l = (ir_loop *)pdeq_getl(block_worklist);
     int i, n_elems = get_loop_n_elements(l);
 
-    /* The header is initialized with the freqency of the full loop times the iteration weight. */
+    /* The header is initialized with the frequency of the full loop times the iteration weight. */
     check_proper_head(l, get_loop_element(l, 0).son);
 
     for (i = 0; i < n_elems; ++i) {
@@ -179,9 +399,14 @@ void compute_execution_frequency(ir_graph *irg, int default_loop_weight, double
   exception_prob = exception_probability;
   if (!exec_freq_set) exec_freq_set = new_set(exec_freq_cmp, 256);
 
+  precompute_cond_evaluation();
   construct_intervals(current_ir_graph);
   compute_frequency(default_loop_weight);
 
+  set_irg_exec_freq_state(irg, exec_freq_consistent);
+  if (get_irp_exec_freq_state() == exec_freq_none)
+    set_irp_exec_freq_state(exec_freq_inconsistent);
+
   /*
     dump_loop_tree     (current_ir_graph, "-execfreq");
     dump_ir_block_graph(current_ir_graph, "-execfreq");
@@ -198,10 +423,53 @@ void compute_execution_frequencies(int default_loop_weight, double exception_pro
   for (i = 0; i < n_irgs; ++i) {
     compute_execution_frequency(get_irp_irg(i), default_loop_weight, exception_probability);
   }
+  set_irp_exec_freq_state(exec_freq_consistent);
 }
 
 /** free occupied memory, reset */
 void free_execution_frequency(void) {
+  int i, n_irgs = get_irp_n_irgs();
   free_intervals();
   del_set(exec_freq_set);
+
+  for (i = 0; i < n_irgs; ++i)
+    set_irg_exec_freq_state(get_irp_irg(i), exec_freq_none);
+  set_irp_exec_freq_state(exec_freq_none);
+}
+
+exec_freq_state get_irg_exec_freq_state(ir_graph *irg) {
+  return irg->execfreq_state;
+}
+void            set_irg_exec_freq_state(ir_graph *irg, exec_freq_state s) {
+  if ((get_irp_exec_freq_state() == exec_freq_consistent && s != exec_freq_consistent) ||
+      (get_irp_exec_freq_state() == exec_freq_none       && s != exec_freq_none))
+    irp->execfreq_state = exec_freq_inconsistent;
+  irg->execfreq_state = s;
+}
+
+/* Sets irg and irp exec freq state to inconsistent if it is set to consistent. */
+void            set_irg_exec_freq_state_inconsistent(ir_graph *irg) {
+  if (get_irg_exec_freq_state(irg) == exec_freq_consistent)
+    set_irg_exec_freq_state(irg, exec_freq_inconsistent);
+}
+
+void set_irp_exec_freq_state(exec_freq_state s) {
+  irp->execfreq_state = s;
+}
+
+exec_freq_state get_irp_exec_freq_state(void) {
+  return irp->execfreq_state;
+}
+
+/* Sets irp and all irg exec freq states to inconsistent if it is set to consistent. */
+void            set_irp_exec_freq_state_inconsistent(void) {
+  if (get_irp_exec_freq_state() != exec_freq_none) {
+    int i, n_irgs = get_irp_n_irgs();
+    set_irp_exec_freq_state(exec_freq_inconsistent);
+    for (i = 0; i < n_irgs; ++i) {
+      ir_graph *irg = get_irp_irg(i);
+      if (get_irg_exec_freq_state(irg) != exec_freq_none)
+	irg->execfreq_state = exec_freq_inconsistent;
+    }
+  }
 }