* invoke.texi (-malign-double): Re-add lost warning.

	* i386-protos.h (x86_output_mi_thunk): Declare.
	* unix.h (ASM_OUTPUT_MI_THUNK): Move offline to ...
	* i386.c (x86_output_mi_thunk): ... here; handle 64bits.

	* dwarf2out.c (output_call_frame_info): Do not skip unwind info
	when flag_asynchronous_unwind_tables is set.

	* flags.h (flag_reorder_functions): Declare.
	* function.c (prepare_function_start): Initialize frequnecy.
	* params.def (HOT_BB_COUNT_FRACTION, HOT_BB_FREQUENCY_FRACTION): New paramters.
	* Makefile.in (predict.o): Add dependency on target.h and params.h
	* defaults.h (HOT_TEXT_SECTION_NAME,
	UNLIKELY_EXECUTED_TEXT_SECTION_NAME): New macros.
	* predict.c (choose_function_section): New function.
	(estimate_bb_frequencies): Use it.
	* toplev.c (flag_reorder_functions): New global variable.
	(lang_independent_options): New.
	(parse_options_and_default_flags): Set.
	* varasm.c (assemble_start_function): Bypass functdion alignment
	for never executed functions.
	* invoke.texi (-freorder-blocks, -freorder-functions): Document.
	(param hot-bb-count-fraction, hot-bb-frequency-fraction): New.
	* tm.texi (HOT_TEXT_SECTION_NAME, UNLIKELY_EXECUTED_TEXT_SECTION_NAME):
	Document.

	Thu Jan  3 21:52:09 CET 2002  Jan Hubicka  <jh@suse.cz>

	* predict.c: Inlude profile.h
	(MIN_COUNT): Rename to MIN_COUNT_FRACTION
	(maybe_hot_bb_p, probably_cold_bb_p, probably_never_executed_bb_p):
	Use the information about maximal counter in the program.

	Thu Dec 20 22:14:00 CET 2001  Jan Hubicka  <jh@suse.cz>

	* basic-block.h (maybe_hot_bb_p, probably_cold_bb_p,
	probably_never_executed_bb_p): New functions.
	* cfgcleanup.c (outgoing_edges_match): Use them.
	* predict.c (MIN_COUNT, MIN_FREQUENCY): New macros.
	(maybe_hot_bb_p, probably_cold_bb_p,
	probably_never_executed_bb_p): New functions.

	* function.h (function): Add new field function_frequency.
	* predict.c (compute_function_frequency): New function.
	(estimate_probability): Call it.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@53478 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 184 insertions, 90 deletions

diff --git a/gcc/predict.c b/gcc/predict.c
index 5896c10a191..f457817956d 100644
--- a/gcc/predict.c
+++ b/gcc/predict.c
@@ -45,7 +45,10 @@ Software Foundation, 59 Temple Place - Suite 330, Boston, MA
 #include "recog.h"
 #include "expr.h"
 #include "predict.h"
+#include "profile.h"
 #include "real.h"
+#include "params.h"
+#include "target.h"
 
 /* real constants: 0, 1, 1-1/REG_BR_PROB_BASE, REG_BR_PROB_BASE, 0.5,
                    REAL_BB_FREQ_MAX.  */
@@ -75,6 +78,8 @@ static void process_note_predictions	 PARAMS ((basic_block, int *, int *,
 static void process_note_prediction	 PARAMS ((basic_block, int *, int *,
                                                   sbitmap *, int, int));
 static bool last_basic_block_p           PARAMS ((basic_block));
+static void compute_function_frequency	 PARAMS ((void));
+static void choose_function_section	 PARAMS ((void));
 
 /* Information we hold about each branch predictor.
    Filled using information from predict.def.  */
@@ -103,6 +108,54 @@ static const struct predictor_info predictor_info[]= {
   {NULL, 0, 0}
 };
 #undef DEF_PREDICTOR
+
+/* Return true in case BB can be CPU intensive and should be optimized
+   for maximal perofmrance.  */
+
+bool
+maybe_hot_bb_p (bb)
+     basic_block bb;
+{
+  if (profile_info.count_profiles_merged
+      && flag_branch_probabilities
+      && (bb->count
+	  < profile_info.max_counter_in_program
+	  / PARAM_VALUE (HOT_BB_COUNT_FRACTION)))
+    return false;
+  if (bb->frequency < BB_FREQ_MAX / PARAM_VALUE (HOT_BB_FREQUENCY_FRACTION))
+    return false;
+  return true;
+}
+
+/* Return true in case BB is cold and should be optimized for size.  */
+
+bool
+probably_cold_bb_p (bb)
+     basic_block bb;
+{
+  if (profile_info.count_profiles_merged
+      && flag_branch_probabilities
+      && (bb->count
+	  < profile_info.max_counter_in_program
+	  / PARAM_VALUE (HOT_BB_COUNT_FRACTION)))
+    return true;
+  if (bb->frequency < BB_FREQ_MAX / PARAM_VALUE (HOT_BB_FREQUENCY_FRACTION))
+    return true;
+  return false;
+}
+
+/* Return true in case BB is probably never executed.  */
+bool
+probably_never_executed_bb_p (bb)
+	basic_block bb;
+{
+  if (profile_info.count_profiles_merged
+      && flag_branch_probabilities)
+    return ((bb->count + profile_info.count_profiles_merged / 2)
+	    / profile_info.count_profiles_merged) == 0;
+  return false;
+}
+
 /* Return true if the one of outgoing edges is already predicted by
    PREDICTOR.  */
 
@@ -1095,118 +1148,159 @@ estimate_bb_frequencies (loops)
   REAL_VALUE_TYPE freq_max;
   enum machine_mode double_mode = TYPE_MODE (double_type_node);
 
-  REAL_VALUE_FROM_INT (real_zero, 0, 0, double_mode);
-  REAL_VALUE_FROM_INT (real_one, 1, 0, double_mode);
-  REAL_VALUE_FROM_INT (real_br_prob_base, REG_BR_PROB_BASE, 0, double_mode);
-  REAL_VALUE_FROM_INT (real_bb_freq_max, BB_FREQ_MAX, 0, double_mode);
-  REAL_VALUE_FROM_INT (real_one_half, 2, 0, double_mode);
+  if (flag_branch_probabilities)
+    counts_to_freqs ();
+  else
+    {
+      REAL_VALUE_FROM_INT (real_zero, 0, 0, double_mode);
+      REAL_VALUE_FROM_INT (real_one, 1, 0, double_mode);
+      REAL_VALUE_FROM_INT (real_br_prob_base, REG_BR_PROB_BASE, 0, double_mode);
+      REAL_VALUE_FROM_INT (real_bb_freq_max, BB_FREQ_MAX, 0, double_mode);
+      REAL_VALUE_FROM_INT (real_one_half, 2, 0, double_mode);
 
-  REAL_ARITHMETIC (real_one_half, RDIV_EXPR, real_one, real_one_half);
+      REAL_ARITHMETIC (real_one_half, RDIV_EXPR, real_one, real_one_half);
 
-  REAL_ARITHMETIC (real_almost_one, RDIV_EXPR, real_one, real_br_prob_base);
-  REAL_ARITHMETIC (real_almost_one, MINUS_EXPR, real_one, real_almost_one);
+      REAL_ARITHMETIC (real_almost_one, RDIV_EXPR, real_one, real_br_prob_base);
+      REAL_ARITHMETIC (real_almost_one, MINUS_EXPR, real_one, real_almost_one);
 
-  mark_dfs_back_edges ();
-  if (flag_branch_probabilities)
-    {
-      counts_to_freqs ();
-      return;
-    }
+      mark_dfs_back_edges ();
+      /* Fill in the probability values in flowgraph based on the REG_BR_PROB
+         notes.  */
+      for (i = 0; i < n_basic_blocks; i++)
+	{
+	  rtx last_insn = BLOCK_END (i);
 
-  /* Fill in the probability values in flowgraph based on the REG_BR_PROB
-     notes.  */
-  for (i = 0; i < n_basic_blocks; i++)
-    {
-      rtx last_insn = BLOCK_END (i);
+	  if (GET_CODE (last_insn) != JUMP_INSN || !any_condjump_p (last_insn)
+	      /* Avoid handling of conditional jumps jumping to fallthru edge.  */
+	      || BASIC_BLOCK (i)->succ->succ_next == NULL)
+	    {
+	      /* We can predict only conditional jumps at the moment.
+	         Expect each edge to be equally probable.
+	         ?? In the future we want to make abnormal edges improbable.  */
+	      int nedges = 0;
+	      edge e;
 
-      if (GET_CODE (last_insn) != JUMP_INSN || !any_condjump_p (last_insn)
-	  /* Avoid handling of conditional jumps jumping to fallthru edge.  */
-	  || BASIC_BLOCK (i)->succ->succ_next == NULL)
+	      for (e = BASIC_BLOCK (i)->succ; e; e = e->succ_next)
+		{
+		  nedges++;
+		  if (e->probability != 0)
+		    break;
+		}
+	      if (!e)
+		for (e = BASIC_BLOCK (i)->succ; e; e = e->succ_next)
+		  e->probability = (REG_BR_PROB_BASE + nedges / 2) / nedges;
+	    }
+	}
+
+      ENTRY_BLOCK_PTR->succ->probability = REG_BR_PROB_BASE;
+
+      /* Set up block info for each basic block.  */
+      alloc_aux_for_blocks (sizeof (struct block_info_def));
+      alloc_aux_for_edges (sizeof (struct edge_info_def));
+      for (i = -2; i < n_basic_blocks; i++)
 	{
-	  /* We can predict only conditional jumps at the moment.
-	     Expect each edge to be equally probable.
-	     ?? In the future we want to make abnormal edges improbable.  */
-	  int nedges = 0;
 	  edge e;
+	  basic_block bb;
 
-	  for (e = BASIC_BLOCK (i)->succ; e; e = e->succ_next)
+	  if (i == -2)
+	    bb = ENTRY_BLOCK_PTR;
+	  else if (i == -1)
+	    bb = EXIT_BLOCK_PTR;
+	  else
+	    bb = BASIC_BLOCK (i);
+
+	  BLOCK_INFO (bb)->tovisit = 0;
+	  for (e = bb->succ; e; e = e->succ_next)
 	    {
-	      nedges++;
-	      if (e->probability != 0)
-		break;
+
+	      REAL_VALUE_FROM_INT (EDGE_INFO (e)->back_edge_prob,
+				   e->probability, 0, double_mode);
+	      REAL_ARITHMETIC (EDGE_INFO (e)->back_edge_prob,
+			       RDIV_EXPR, EDGE_INFO (e)->back_edge_prob,
+			       real_br_prob_base);
 	    }
-	  if (!e)
-	    for (e = BASIC_BLOCK (i)->succ; e; e = e->succ_next)
-	      e->probability = (REG_BR_PROB_BASE + nedges / 2) / nedges;
 	}
-    }
 
-  ENTRY_BLOCK_PTR->succ->probability = REG_BR_PROB_BASE;
+      /* First compute probabilities locally for each loop from innermost
+         to outermost to examine probabilities for back edges.  */
+      estimate_loops_at_level (loops->tree_root);
 
-  /* Set up block info for each basic block.  */
-  alloc_aux_for_blocks (sizeof (struct block_info_def));
-  alloc_aux_for_edges (sizeof (struct edge_info_def));
-  for (i = -2; i < n_basic_blocks; i++)
-    {
-      edge e;
-      basic_block bb;
+      /* Now fake loop around whole function to finalize probabilities.  */
+      for (i = 0; i < n_basic_blocks; i++)
+	BLOCK_INFO (BASIC_BLOCK (i))->tovisit = 1;
 
-      if (i == -2)
-	bb = ENTRY_BLOCK_PTR;
-      else if (i == -1)
-	bb = EXIT_BLOCK_PTR;
-      else
-	bb = BASIC_BLOCK (i);
+      BLOCK_INFO (ENTRY_BLOCK_PTR)->tovisit = 1;
+      BLOCK_INFO (EXIT_BLOCK_PTR)->tovisit = 1;
+      propagate_freq (ENTRY_BLOCK_PTR);
 
-      BLOCK_INFO (bb)->tovisit = 0;
-      for (e = bb->succ; e; e = e->succ_next)
+      memcpy (&freq_max, &real_zero, sizeof (real_zero));
+      for (i = 0; i < n_basic_blocks; i++)
+	if (REAL_VALUES_LESS
+	    (freq_max, BLOCK_INFO (BASIC_BLOCK (i))->frequency))
+	  memcpy (&freq_max, &BLOCK_INFO (BASIC_BLOCK (i))->frequency,
+		  sizeof (freq_max));
+
+      for (i = -2; i < n_basic_blocks; i++)
 	{
-	
-	  REAL_VALUE_FROM_INT (EDGE_INFO (e)->back_edge_prob,
-			       e->probability, 0, double_mode);
-	  REAL_ARITHMETIC (EDGE_INFO (e)->back_edge_prob,
-			   RDIV_EXPR, EDGE_INFO (e)->back_edge_prob,
-			   real_br_prob_base);
-	}
-    }
+	  basic_block bb;
+	  REAL_VALUE_TYPE tmp;
 
-  /* First compute probabilities locally for each loop from innermost
-     to outermost to examine probabilities for back edges.  */
-  estimate_loops_at_level (loops->tree_root);
+	  if (i == -2)
+	    bb = ENTRY_BLOCK_PTR;
+	  else if (i == -1)
+	    bb = EXIT_BLOCK_PTR;
+	  else
+	    bb = BASIC_BLOCK (i);
 
-  /* Now fake loop around whole function to finalize probabilities.  */
-  for (i = 0; i < n_basic_blocks; i++)
-    BLOCK_INFO (BASIC_BLOCK (i))->tovisit = 1;
+	  REAL_ARITHMETIC (tmp, MULT_EXPR, BLOCK_INFO (bb)->frequency,
+			   real_bb_freq_max);
+	  REAL_ARITHMETIC (tmp, RDIV_EXPR, tmp, freq_max);
+	  REAL_ARITHMETIC (tmp, PLUS_EXPR, tmp, real_one_half);
+	  bb->frequency = REAL_VALUE_UNSIGNED_FIX (tmp);
+	}
 
-  BLOCK_INFO (ENTRY_BLOCK_PTR)->tovisit = 1;
-  BLOCK_INFO (EXIT_BLOCK_PTR)->tovisit = 1;
-  propagate_freq (ENTRY_BLOCK_PTR);
+      free_aux_for_blocks ();
+      free_aux_for_edges ();
+    }
+  compute_function_frequency ();
+  if (flag_reorder_functions)
+    choose_function_section ();
+}
 
-  memcpy (&freq_max, &real_zero, sizeof (real_zero));
+/* Decide whether function is hot, cold or unlikely executed.  */
+static void
+compute_function_frequency ()
+{
+  int i;
+  if (!profile_info.count_profiles_merged
+      || !flag_branch_probabilities)
+    return;
+  cfun->function_frequency = FUNCTION_FREQUENCY_UNLIKELY_EXECUTED;
   for (i = 0; i < n_basic_blocks; i++)
-    if (REAL_VALUES_LESS (freq_max, BLOCK_INFO (BASIC_BLOCK (i))->frequency))
-      memcpy (&freq_max, &BLOCK_INFO (BASIC_BLOCK (i))->frequency,
-	      sizeof (freq_max));
-
-  for (i = -2; i < n_basic_blocks; i++)
     {
-      basic_block bb;
-      REAL_VALUE_TYPE tmp;
-
-      if (i == -2)
-	bb = ENTRY_BLOCK_PTR;
-      else if (i == -1)
-	bb = EXIT_BLOCK_PTR;
-      else
-	bb = BASIC_BLOCK (i);
-
-      REAL_ARITHMETIC (tmp, MULT_EXPR, BLOCK_INFO (bb)->frequency,
-		       real_bb_freq_max);
-      REAL_ARITHMETIC (tmp, RDIV_EXPR, tmp, freq_max);
-      REAL_ARITHMETIC (tmp, PLUS_EXPR, tmp, real_one_half);
-      bb->frequency = REAL_VALUE_UNSIGNED_FIX (tmp);
+      basic_block bb = BASIC_BLOCK (i);
+      if (maybe_hot_bb_p (bb))
+	{
+	  cfun->function_frequency = FUNCTION_FREQUENCY_HOT;
+	  return;
+	}
+      if (!probably_never_executed_bb_p (bb))
+	cfun->function_frequency = FUNCTION_FREQUENCY_NORMAL;
     }
+}
 
-  free_aux_for_blocks ();
-  free_aux_for_edges ();
+/* Choose appropriate section for the function.  */
+static void
+choose_function_section ()
+{
+  if (DECL_SECTION_NAME (current_function_decl)
+      || !targetm.have_named_sections)
+    return;
+  if (cfun->function_frequency == FUNCTION_FREQUENCY_HOT)
+    DECL_SECTION_NAME (current_function_decl) =
+      build_string (strlen (HOT_TEXT_SECTION_NAME), HOT_TEXT_SECTION_NAME);
+  if (cfun->function_frequency == FUNCTION_FREQUENCY_UNLIKELY_EXECUTED)
+    DECL_SECTION_NAME (current_function_decl) =
+      build_string (strlen (UNLIKELY_EXECUTED_TEXT_SECTION_NAME),
+		    UNLIKELY_EXECUTED_TEXT_SECTION_NAME);
 }