re PR target/65697 (__atomic memory barriers not strong enough for __sync builtins)
[gcc.git] / gcc / predict.c
index 56e45d963c061260369f9928685eecc188f3e9ca..9a69c6f4e39a7017320cfe4cae4e36b95bf0c77a 100644 (file)
@@ -1,5 +1,5 @@
 /* Branch prediction routines for the GNU compiler.
-   Copyright (C) 2000-2014 Free Software Foundation, Inc.
+   Copyright (C) 2000-2015 Free Software Foundation, Inc.
 
 This file is part of GCC.
 
@@ -31,31 +31,42 @@ along with GCC; see the file COPYING3.  If not see
 #include "system.h"
 #include "coretypes.h"
 #include "tm.h"
+#include "alias.h"
+#include "symtab.h"
 #include "tree.h"
+#include "fold-const.h"
 #include "calls.h"
 #include "rtl.h"
 #include "tm_p.h"
 #include "hard-reg-set.h"
+#include "predict.h"
+#include "function.h"
+#include "dominance.h"
+#include "cfg.h"
+#include "cfganal.h"
 #include "basic-block.h"
 #include "insn-config.h"
 #include "regs.h"
 #include "flags.h"
-#include "function.h"
+#include "profile.h"
 #include "except.h"
 #include "diagnostic-core.h"
 #include "recog.h"
+#include "expmed.h"
+#include "dojump.h"
+#include "explow.h"
+#include "emit-rtl.h"
+#include "varasm.h"
+#include "stmt.h"
 #include "expr.h"
-#include "predict.h"
 #include "coverage.h"
 #include "sreal.h"
 #include "params.h"
 #include "target.h"
 #include "cfgloop.h"
-#include "hash-map.h"
 #include "tree-ssa-alias.h"
 #include "internal-fn.h"
 #include "gimple-expr.h"
-#include "is-a.h"
 #include "gimple.h"
 #include "gimple-iterator.h"
 #include "gimple-ssa.h"
@@ -67,11 +78,10 @@ along with GCC; see the file COPYING3.  If not see
 #include "tree-ssa-loop.h"
 #include "tree-pass.h"
 #include "tree-scalar-evolution.h"
-#include "cfgloop.h"
 
 /* real constants: 0, 1, 1-1/REG_BR_PROB_BASE, REG_BR_PROB_BASE,
                   1/REG_BR_PROB_BASE, 0.5, BB_FREQ_MAX.  */
-static sreal real_zero, real_one, real_almost_one, real_br_prob_base,
+static sreal real_almost_one, real_br_prob_base,
             real_inv_br_prob_base, real_one_half, real_bb_freq_max;
 
 static void combine_predictions_for_insn (rtx_insn *, basic_block);
@@ -114,7 +124,8 @@ static inline bool
 maybe_hot_frequency_p (struct function *fun, int freq)
 {
   struct cgraph_node *node = cgraph_node::get (fun->decl);
-  if (!profile_info || !flag_branch_probabilities)
+  if (!profile_info
+      || !opt_for_fn (fun->decl, flag_branch_probabilities))
     {
       if (node->frequency == NODE_FREQUENCY_UNLIKELY_EXECUTED)
         return false;
@@ -161,7 +172,7 @@ set_hot_bb_threshold (gcov_type min)
 
 /* Return TRUE if frequency FREQ is considered to be hot.  */
 
-static inline bool
+bool
 maybe_hot_count_p (struct function *fun, gcov_type count)
 {
   if (fun && profile_status_for_fn (fun) != PROFILE_READ)
@@ -184,39 +195,6 @@ maybe_hot_bb_p (struct function *fun, const_basic_block bb)
   return maybe_hot_frequency_p (fun, bb->frequency);
 }
 
-/* Return true if the call can be hot.  */
-
-bool
-cgraph_edge::maybe_hot_p (void)
-{
-  if (profile_info && flag_branch_probabilities
-      && !maybe_hot_count_p (NULL, count))
-    return false;
-  if (caller->frequency == NODE_FREQUENCY_UNLIKELY_EXECUTED
-      || (callee
-         && callee->frequency == NODE_FREQUENCY_UNLIKELY_EXECUTED))
-    return false;
-  if (caller->frequency > NODE_FREQUENCY_UNLIKELY_EXECUTED
-      && (callee
-         && callee->frequency <= NODE_FREQUENCY_EXECUTED_ONCE))
-    return false;
-  if (optimize_size)
-    return false;
-  if (caller->frequency == NODE_FREQUENCY_HOT)
-    return true;
-  if (caller->frequency == NODE_FREQUENCY_EXECUTED_ONCE
-      && frequency < CGRAPH_FREQ_BASE * 3 / 2)
-    return false;
-  if (flag_guess_branch_prob)
-    {
-      if (PARAM_VALUE (HOT_BB_FREQUENCY_FRACTION) == 0
-         || frequency <= (CGRAPH_FREQ_BASE
-                                / PARAM_VALUE (HOT_BB_FREQUENCY_FRACTION)))
-        return false;
-    }
-  return true;
-}
-
 /* Return true in case BB can be CPU intensive and should be optimized
    for maximal performance.  */
 
@@ -228,8 +206,6 @@ maybe_hot_edge_p (edge e)
   return maybe_hot_frequency_p (cfun, EDGE_FREQUENCY (e));
 }
 
-
-
 /* Return true if profile COUNT and FREQUENCY, or function FUN static
    node frequency reflects never being executed.  */
    
@@ -238,34 +214,34 @@ probably_never_executed (struct function *fun,
                          gcov_type count, int frequency)
 {
   gcc_checking_assert (fun);
-  if (profile_status_for_fn (cfun) == PROFILE_READ)
+  if (profile_status_for_fn (fun) == PROFILE_READ)
     {
       int unlikely_count_fraction = PARAM_VALUE (UNLIKELY_BB_COUNT_FRACTION);
       if (count * unlikely_count_fraction >= profile_info->runs)
        return false;
       if (!frequency)
        return true;
-      if (!ENTRY_BLOCK_PTR_FOR_FN (cfun)->frequency)
+      if (!ENTRY_BLOCK_PTR_FOR_FN (fun)->frequency)
        return false;
-      if (ENTRY_BLOCK_PTR_FOR_FN (cfun)->count)
+      if (ENTRY_BLOCK_PTR_FOR_FN (fun)->count)
        {
           gcov_type computed_count;
           /* Check for possibility of overflow, in which case entry bb count
              is large enough to do the division first without losing much
              precision.  */
-         if (ENTRY_BLOCK_PTR_FOR_FN (cfun)->count < REG_BR_PROB_BASE *
+         if (ENTRY_BLOCK_PTR_FOR_FN (fun)->count < REG_BR_PROB_BASE *
              REG_BR_PROB_BASE)
             {
               gcov_type scaled_count
-                 = frequency * ENTRY_BLOCK_PTR_FOR_FN (cfun)->count *
+                 = frequency * ENTRY_BLOCK_PTR_FOR_FN (fun)->count *
             unlikely_count_fraction;
              computed_count = RDIV (scaled_count,
-                                    ENTRY_BLOCK_PTR_FOR_FN (cfun)->frequency);
+                                    ENTRY_BLOCK_PTR_FOR_FN (fun)->frequency);
             }
           else
             {
-             computed_count = RDIV (ENTRY_BLOCK_PTR_FOR_FN (cfun)->count,
-                                    ENTRY_BLOCK_PTR_FOR_FN (cfun)->frequency);
+             computed_count = RDIV (ENTRY_BLOCK_PTR_FOR_FN (fun)->count,
+                                    ENTRY_BLOCK_PTR_FOR_FN (fun)->frequency);
               computed_count *= frequency * unlikely_count_fraction;
             }
           if (computed_count >= profile_info->runs)
@@ -273,7 +249,7 @@ probably_never_executed (struct function *fun,
        }
       return true;
     }
-  if ((!profile_info || !flag_branch_probabilities)
+  if ((!profile_info || !(opt_for_fn (fun->decl, flag_branch_probabilities)))
       && (cgraph_node::get (fun->decl)->frequency
          == NODE_FREQUENCY_UNLIKELY_EXECUTED))
     return true;
@@ -298,29 +274,13 @@ probably_never_executed_edge_p (struct function *fun, edge e)
   return probably_never_executed (fun, e->count, EDGE_FREQUENCY (e));
 }
 
-/* Return true if function should be optimized for size.  */
-
-bool
-cgraph_node::optimize_for_size_p (void)
-{
-  if (optimize_size)
-    return true;
-  if (frequency == NODE_FREQUENCY_UNLIKELY_EXECUTED)
-    return true;
-  else
-    return false;
-}
-
 /* Return true when current function should always be optimized for size.  */
 
 bool
 optimize_function_for_size_p (struct function *fun)
 {
-  if (optimize_size)
-    return true;
   if (!fun || !fun->decl)
-    return false;
-
+    return optimize_size;
   cgraph_node *n = cgraph_node::get (fun->decl);
   return n && n->optimize_for_size_p ();
 }
@@ -739,10 +699,10 @@ dump_prediction (FILE *file, enum br_predictor predictor, int probability,
 
   if (bb->count)
     {
-      fprintf (file, "  exec %"PRId64, bb->count);
+      fprintf (file, "  exec %" PRId64, bb->count);
       if (e)
        {
-         fprintf (file, " hit %"PRId64, e->count);
+         fprintf (file, " hit %" PRId64, e->count);
          fprintf (file, " (%.1f%%)", e->count * 100.0 / bb->count);
        }
     }
@@ -1104,7 +1064,7 @@ get_base_value (tree t)
    Otherwise return false and set LOOP_INVAIANT to NULL.  */
 
 static bool
-is_comparison_with_loop_invariant_p (gimple stmt, struct loop *loop,
+is_comparison_with_loop_invariant_p (gcond *stmt, struct loop *loop,
                                     tree *loop_invariant,
                                     enum tree_code *compare_code,
                                     tree *loop_step,
@@ -1269,7 +1229,8 @@ predict_iv_comparison (struct loop *loop, basic_block bb,
   stmt = last_stmt (bb);
   if (!stmt || gimple_code (stmt) != GIMPLE_COND)
     return;
-  if (!is_comparison_with_loop_invariant_p (stmt, loop, &compare_var,
+  if (!is_comparison_with_loop_invariant_p (as_a <gcond *> (stmt),
+                                           loop, &compare_var,
                                            &compare_code,
                                            &compare_step_var,
                                            &compare_base))
@@ -1442,12 +1403,19 @@ predict_extra_loop_exits (edge exit_edge)
 {
   unsigned i;
   bool check_value_one;
-  gimple phi_stmt;
+  gimple lhs_def_stmt;
+  gphi *phi_stmt;
   tree cmp_rhs, cmp_lhs;
-  gimple cmp_stmt = last_stmt (exit_edge->src);
+  gimple last;
+  gcond *cmp_stmt;
 
-  if (!cmp_stmt || gimple_code (cmp_stmt) != GIMPLE_COND)
+  last = last_stmt (exit_edge->src);
+  if (!last)
     return;
+  cmp_stmt = dyn_cast <gcond *> (last);
+  if (!cmp_stmt)
+    return;
+
   cmp_rhs = gimple_cond_rhs (cmp_stmt);
   cmp_lhs = gimple_cond_lhs (cmp_stmt);
   if (!TREE_CONSTANT (cmp_rhs)
@@ -1463,8 +1431,12 @@ predict_extra_loop_exits (edge exit_edge)
                    ^ (gimple_cond_code (cmp_stmt) == EQ_EXPR))
                    ^ ((exit_edge->flags & EDGE_TRUE_VALUE) != 0));
 
-  phi_stmt = SSA_NAME_DEF_STMT (cmp_lhs);
-  if (!phi_stmt || gimple_code (phi_stmt) != GIMPLE_PHI)
+  lhs_def_stmt = SSA_NAME_DEF_STMT (cmp_lhs);
+  if (!lhs_def_stmt)
+    return;
+
+  phi_stmt = dyn_cast <gphi *> (lhs_def_stmt);
+  if (!phi_stmt)
     return;
 
   for (i = 0; i < gimple_phi_num_args (phi_stmt); i++)
@@ -1510,7 +1482,7 @@ predict_loops (void)
       tree loop_bound_step = NULL;
       tree loop_bound_var = NULL;
       tree loop_iv_base = NULL;
-      gimple stmt = NULL;
+      gcond *stmt = NULL;
 
       exits = get_loop_exit_edges (loop);
       n_exits = exits.length ();
@@ -1577,12 +1549,12 @@ predict_loops (void)
        if (nb_iter->stmt
            && gimple_code (nb_iter->stmt) == GIMPLE_COND)
          {
-           stmt = nb_iter->stmt;
+           stmt = as_a <gcond *> (nb_iter->stmt);
            break;
          }
       if (!stmt && last_stmt (loop->header)
          && gimple_code (last_stmt (loop->header)) == GIMPLE_COND)
-       stmt = last_stmt (loop->header);
+       stmt = as_a <gcond *> (last_stmt (loop->header));
       if (stmt)
        is_comparison_with_loop_invariant_p (stmt, loop,
                                             &loop_bound_var,
@@ -1902,6 +1874,8 @@ expr_expected_value_1 (tree type, tree op0, enum tree_code code,
                if (predictor)
                  *predictor = PRED_COMPARE_AND_SWAP;
                return boolean_true_node;
+             default:
+               break;
            }
        }
 
@@ -2138,10 +2112,10 @@ return_prediction (tree val, enum prediction *prediction)
 static void
 apply_return_prediction (void)
 {
-  gimple return_stmt = NULL;
+  greturn *return_stmt = NULL;
   tree return_val;
   edge e;
-  gimple phi;
+  gphi *phi;
   int phi_num_args, i;
   enum br_predictor pred;
   enum prediction direction;
@@ -2149,10 +2123,13 @@ apply_return_prediction (void)
 
   FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR_FOR_FN (cfun)->preds)
     {
-      return_stmt = last_stmt (e->src);
-      if (return_stmt
-         && gimple_code (return_stmt) == GIMPLE_RETURN)
-       break;
+      gimple last = last_stmt (e->src);
+      if (last
+         && gimple_code (last) == GIMPLE_RETURN)
+       {
+         return_stmt = as_a <greturn *> (last);
+         break;
+       }
     }
   if (!e)
     return;
@@ -2163,7 +2140,7 @@ apply_return_prediction (void)
       || !SSA_NAME_DEF_STMT (return_val)
       || gimple_code (SSA_NAME_DEF_STMT (return_val)) != GIMPLE_PHI)
     return;
-  phi = SSA_NAME_DEF_STMT (return_val);
+  phi = as_a <gphi *> (SSA_NAME_DEF_STMT (return_val));
   phi_num_args = gimple_phi_num_args (phi);
   pred = return_prediction (PHI_ARG_DEF (phi, 0), &direction);
 
@@ -2268,12 +2245,12 @@ tree_estimate_probability_bb (basic_block bb)
          gimple_stmt_iterator gi;
          for (gi = gsi_start_bb (e->dest); !gsi_end_p (gi); gsi_next (&gi))
            {
-             gimple stmt = gsi_stmt (gi);
+             glabel *label_stmt = dyn_cast <glabel *> (gsi_stmt (gi));
              tree decl;
 
-             if (gimple_code (stmt) != GIMPLE_LABEL)
+             if (!label_stmt)
                break;
-             decl = gimple_label_label (stmt);
+             decl = gimple_label_label (label_stmt);
              if (DECL_ARTIFICIAL (decl))
                continue;
 
@@ -2520,6 +2497,7 @@ struct edge_prob_info
 };
 
 #define BLOCK_INFO(B)  ((block_info *) (B)->aux)
+#undef EDGE_INFO
 #define EDGE_INFO(E)   ((edge_prob_info *) (E)->aux)
 
 /* Helper function for estimate_bb_frequencies.
@@ -2562,15 +2540,13 @@ propagate_freq (basic_block head, bitmap tovisit)
        bb->count = bb->frequency = 0;
     }
 
-  memcpy (&BLOCK_INFO (head)->frequency, &real_one, sizeof (real_one));
+  BLOCK_INFO (head)->frequency = 1;
   last = head;
   for (bb = head; bb; bb = nextbb)
     {
       edge_iterator ei;
-      sreal cyclic_probability, frequency;
-
-      memcpy (&cyclic_probability, &real_zero, sizeof (real_zero));
-      memcpy (&frequency, &real_zero, sizeof (real_zero));
+      sreal cyclic_probability = 0;
+      sreal frequency = 0;
 
       nextbb = BLOCK_INFO (bb)->next;
       BLOCK_INFO (bb)->next = NULL;
@@ -2587,42 +2563,34 @@ propagate_freq (basic_block head, bitmap tovisit)
          FOR_EACH_EDGE (e, ei, bb->preds)
            if (EDGE_INFO (e)->back_edge)
              {
-               sreal_add (&cyclic_probability, &cyclic_probability,
-                          &EDGE_INFO (e)->back_edge_prob);
+               cyclic_probability += EDGE_INFO (e)->back_edge_prob;
              }
            else if (!(e->flags & EDGE_DFS_BACK))
              {
-               sreal tmp;
-
                /*  frequency += (e->probability
                                  * BLOCK_INFO (e->src)->frequency /
                                  REG_BR_PROB_BASE);  */
 
-               sreal_init (&tmp, e->probability, 0);
-               sreal_mul (&tmp, &tmp, &BLOCK_INFO (e->src)->frequency);
-               sreal_mul (&tmp, &tmp, &real_inv_br_prob_base);
-               sreal_add (&frequency, &frequency, &tmp);
+               sreal tmp = e->probability;
+               tmp *= BLOCK_INFO (e->src)->frequency;
+               tmp *= real_inv_br_prob_base;
+               frequency += tmp;
              }
 
-         if (sreal_compare (&cyclic_probability, &real_zero) == 0)
+         if (cyclic_probability == 0)
            {
-             memcpy (&BLOCK_INFO (bb)->frequency, &frequency,
-                     sizeof (frequency));
+             BLOCK_INFO (bb)->frequency = frequency;
            }
          else
            {
-             if (sreal_compare (&cyclic_probability, &real_almost_one) > 0)
-               {
-                 memcpy (&cyclic_probability, &real_almost_one,
-                         sizeof (real_almost_one));
-               }
+             if (cyclic_probability > real_almost_one)
+               cyclic_probability = real_almost_one;
 
              /* BLOCK_INFO (bb)->frequency = frequency
                                              / (1 - cyclic_probability) */
 
-             sreal_sub (&cyclic_probability, &real_one, &cyclic_probability);
-             sreal_div (&BLOCK_INFO (bb)->frequency,
-                        &frequency, &cyclic_probability);
+             cyclic_probability = sreal (1) - cyclic_probability;
+             BLOCK_INFO (bb)->frequency = frequency / cyclic_probability;
            }
        }
 
@@ -2631,16 +2599,13 @@ propagate_freq (basic_block head, bitmap tovisit)
       e = find_edge (bb, head);
       if (e)
        {
-         sreal tmp;
-
          /* EDGE_INFO (e)->back_edge_prob
             = ((e->probability * BLOCK_INFO (bb)->frequency)
             / REG_BR_PROB_BASE); */
 
-         sreal_init (&tmp, e->probability, 0);
-         sreal_mul (&tmp, &tmp, &BLOCK_INFO (bb)->frequency);
-         sreal_mul (&EDGE_INFO (e)->back_edge_prob,
-                    &tmp, &real_inv_br_prob_base);
+         sreal tmp = e->probability;
+         tmp *= BLOCK_INFO (bb)->frequency;
+         EDGE_INFO (e)->back_edge_prob = tmp * real_inv_br_prob_base;
        }
 
       /* Propagate to successor blocks.  */
@@ -2850,7 +2815,7 @@ counts_to_freqs (void)
   /* Don't overwrite the estimated frequencies when the profile for
      the function is missing.  We may drop this function PROFILE_GUESSED
      later in drop_profile ().  */
-  if (!ENTRY_BLOCK_PTR_FOR_FN (cfun)->count)
+  if (!flag_auto_profile && !ENTRY_BLOCK_PTR_FOR_FN (cfun)->count)
     return 0;
 
   FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR_FOR_FN (cfun), NULL, next_bb)
@@ -2920,13 +2885,11 @@ estimate_bb_frequencies (bool force)
       if (!real_values_initialized)
         {
          real_values_initialized = 1;
-         sreal_init (&real_zero, 0, 0);
-         sreal_init (&real_one, 1, 0);
-         sreal_init (&real_br_prob_base, REG_BR_PROB_BASE, 0);
-         sreal_init (&real_bb_freq_max, BB_FREQ_MAX, 0);
-         sreal_init (&real_one_half, 1, -1);
-         sreal_div (&real_inv_br_prob_base, &real_one, &real_br_prob_base);
-         sreal_sub (&real_almost_one, &real_one, &real_inv_br_prob_base);
+         real_br_prob_base = REG_BR_PROB_BASE;
+         real_bb_freq_max = BB_FREQ_MAX;
+         real_one_half = sreal (1, -1);
+         real_inv_br_prob_base = sreal (1) / real_br_prob_base;
+         real_almost_one = sreal (1) - real_inv_br_prob_base;
        }
 
       mark_dfs_back_edges ();
@@ -2944,10 +2907,8 @@ estimate_bb_frequencies (bool force)
 
          FOR_EACH_EDGE (e, ei, bb->succs)
            {
-             sreal_init (&EDGE_INFO (e)->back_edge_prob, e->probability, 0);
-             sreal_mul (&EDGE_INFO (e)->back_edge_prob,
-                        &EDGE_INFO (e)->back_edge_prob,
-                        &real_inv_br_prob_base);
+             EDGE_INFO (e)->back_edge_prob = e->probability;
+             EDGE_INFO (e)->back_edge_prob *= real_inv_br_prob_base;
            }
        }
 
@@ -2955,19 +2916,16 @@ estimate_bb_frequencies (bool force)
          to outermost to examine frequencies for back edges.  */
       estimate_loops ();
 
-      memcpy (&freq_max, &real_zero, sizeof (real_zero));
+      freq_max = 0;
       FOR_EACH_BB_FN (bb, cfun)
-       if (sreal_compare (&freq_max, &BLOCK_INFO (bb)->frequency) < 0)
-         memcpy (&freq_max, &BLOCK_INFO (bb)->frequency, sizeof (freq_max));
+       if (freq_max < BLOCK_INFO (bb)->frequency)
+         freq_max = BLOCK_INFO (bb)->frequency;
 
-      sreal_div (&freq_max, &real_bb_freq_max, &freq_max);
+      freq_max = real_bb_freq_max / freq_max;
       FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR_FOR_FN (cfun), NULL, next_bb)
        {
-         sreal tmp;
-
-         sreal_mul (&tmp, &BLOCK_INFO (bb)->frequency, &freq_max);
-         sreal_add (&tmp, &tmp, &real_one_half);
-         bb->frequency = sreal_to_int (&tmp);
+         sreal tmp = BLOCK_INFO (bb)->frequency * freq_max + real_one_half;
+         bb->frequency = tmp.to_int ();
        }
 
       free_aux_for_blocks ();
@@ -3077,6 +3035,9 @@ pass_profile::execute (function *fun)
 {
   unsigned nb_loops;
 
+  if (profile_status_for_fn (cfun) == PROFILE_GUESSED)
+    return 0;
+
   loop_optimizer_init (LOOPS_NORMAL);
   if (dump_file && (dump_flags & TDF_DETAILS))
     flow_loops_dump (dump_file, NULL, 0);
@@ -3221,7 +3182,8 @@ rebuild_frequencies (void)
     count_max = MAX (bb->count, count_max);
 
   if (profile_status_for_fn (cfun) == PROFILE_GUESSED
-      || (profile_status_for_fn (cfun) == PROFILE_READ && count_max < REG_BR_PROB_BASE/10))
+      || (!flag_auto_profile && profile_status_for_fn (cfun) == PROFILE_READ
+         && count_max < REG_BR_PROB_BASE/10))
     {
       loop_optimizer_init (0);
       add_noreturn_fake_exit_edges ();