Recover GOTO predictor.

2017-07-31  Jan Hubicka <hubicka@ucw.cz>
	    Martin Liska  <mliska@suse.cz>

	* c-typeck.c (c_finish_goto_label): Build gimple predict
	stament.
2017-07-31  Jan Hubicka <hubicka@ucw.cz>
	    Martin Liska  <mliska@suse.cz>

	* predict.def: Remove old comment and adjust probability.
	* gimplify.c (should_warn_for_implicit_fallthrough): Ignore
	PREDICT statements.
2017-07-31  Jan Hubicka <hubicka@ucw.cz>
	    Martin Liska  <mliska@suse.cz>

	* gcc.dg/predict-15.c: New test.
	* gcc.dg/tree-ssa/vrp24.c: Update scanned pattern.
2017-07-31  Jan Hubicka <hubicka@ucw.cz>
	    Martin Liska  <mliska@suse.cz>

	* pt.c (tsubst_copy): Copy PREDICT_EXPR.
	* semantics.c (finish_goto_stmt): Build gimple predict
	stament.
	* constexpr.c (potential_constant_expression_1): Handle
	PREDICT_EXPR.

Co-Authored-By: Martin Liska <mliska@suse.cz>

From-SVN: r250737

gcc/ChangeLog

+2017-07-31  Jan Hubicka <hubicka@ucw.cz>
+	    Martin Liska  <mliska@suse.cz>
+
+	* predict.def: Remove old comment and adjust probability.
+	* gimplify.c (should_warn_for_implicit_fallthrough): Ignore
+	PREDICT statements.
+
 2017-07-31  Uros Bizjak  <ubizjak@gmail.com>
 
 	PR target/25967

gcc/c/ChangeLog

+2017-07-31  Jan Hubicka <hubicka@ucw.cz>
+	    Martin Liska  <mliska@suse.cz>
+
+	* c-typeck.c (c_finish_goto_label): Build gimple predict
+	stament.
+
 2017-07-31  Martin Liska  <mliska@suse.cz>
 
 	PR sanitize/81530

gcc/c/c-typeck.c

@@ -9824,6 +9824,7 @@ c_finish_goto_label (location_t loc, tree label)
     return NULL_TREE;
   TREE_USED (decl) = 1;
   {
+    add_stmt (build_predict_expr (PRED_GOTO, NOT_TAKEN));
     tree t = build1 (GOTO_EXPR, void_type_node, decl);
     SET_EXPR_LOCATION (t, loc);
     return add_stmt (t);

gcc/cp/ChangeLog

+2017-07-31  Jan Hubicka <hubicka@ucw.cz>
+	    Martin Liska  <mliska@suse.cz>
+
+	* pt.c (tsubst_copy): Copy PREDICT_EXPR.
+	* semantics.c (finish_goto_stmt): Build gimple predict
+	stament.
+	* constexpr.c (potential_constant_expression_1): Handle
+	PREDICT_EXPR.
+
 2017-07-31  Martin Liska  <mliska@suse.cz>
 
 	PR sanitize/81530

gcc/cp/constexpr.c

@@ -5782,6 +5782,7 @@ potential_constant_expression_1 (tree t, bool want_rval, bool strict,
 
     case CLEANUP_STMT:
     case EMPTY_CLASS_EXPR:
+    case PREDICT_EXPR:
       return false;
 
     case GOTO_EXPR:

gcc/cp/pt.c

@@ -15105,6 +15105,8 @@ tsubst_copy (tree t, tree args, tsubst_flags_t complain, tree in_decl)
       return tsubst_binary_left_fold (t, args, complain, in_decl);
     case BINARY_RIGHT_FOLD_EXPR:
       return tsubst_binary_right_fold (t, args, complain, in_decl);
+    case PREDICT_EXPR:
+      return t;
 
     default:
       /* We shouldn't get here, but keep going if !flag_checking.  */

gcc/cp/semantics.c

@@ -41,6 +41,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "omp-general.h"
 #include "convert.h"
 #include "gomp-constants.h"
+#include "predict.h"
 
 /* There routines provide a modular interface to perform many parsing
    operations.  They may therefore be used during actual parsing, or
@@ -630,6 +631,7 @@ finish_goto_stmt (tree destination)
 
   check_goto (destination);
 
+  add_stmt (build_predict_expr (PRED_GOTO, NOT_TAKEN));
   return add_stmt (build_stmt (input_location, GOTO_EXPR, destination));
 }
 

gcc/gimplify.c

@@ -2037,7 +2037,9 @@ should_warn_for_implicit_fallthrough (gimple_stmt_iterator *gsi_p, tree label)
   gsi = *gsi_p;
 
   /* Skip all immediately following labels.  */
-  while (!gsi_end_p (gsi) && gimple_code (gsi_stmt (gsi)) == GIMPLE_LABEL)
+  while (!gsi_end_p (gsi)
+	 && (gimple_code (gsi_stmt (gsi)) == GIMPLE_LABEL
+	     || gimple_code (gsi_stmt (gsi)) == GIMPLE_PREDICT))
     gsi_next (&gsi);
 
   /* { ... something; default:; } */

gcc/predict.def

@@ -132,9 +132,8 @@ DEF_PREDICTOR (PRED_RECURSIVE_CALL, "recursive call", HITRATE (75), 0)
 DEF_PREDICTOR (PRED_TREE_EARLY_RETURN, "early return (on trees)", HITRATE (66),
 	       0)
 
-/* Branch containing goto is probably not taken.
-   FIXME: Currently not used.  */
-DEF_PREDICTOR (PRED_GOTO, "goto", HITRATE (70), 0)
+/* Branch containing goto is probably not taken.  */
+DEF_PREDICTOR (PRED_GOTO, "goto", HITRATE (66), 0)
 
 /* Branch ending with return constant is probably not taken.  */
 DEF_PREDICTOR (PRED_CONST_RETURN, "const return", HITRATE (69), 0)

gcc/testsuite/ChangeLog

+2017-07-31  Jan Hubicka <hubicka@ucw.cz>
+	    Martin Liska  <mliska@suse.cz>
+
+	* gcc.dg/predict-15.c: New test.
+	* gcc.dg/tree-ssa/vrp24.c: Update scanned pattern.
+
 2017-07-31  Uros Bizjak  <ubizjak@gmail.com>
 
 	PR target/25967

gcc/testsuite/gcc.dg/predict-15.c

+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-profile_estimate" } */
+
+int main(int argc, char **argv)
+{
+  if (argc == 123)
+    goto exit;
+  else
+    {
+      return 0;
+    }
+
+exit:
+  return 1;
+}
+
+/* { dg-final { scan-tree-dump "goto heuristics of edge" "profile_estimate"} } */

gcc/testsuite/gcc.dg/tree-ssa/attr-hotcold-2.c

 /* { dg-do compile } */
-/* { dg-options "-O2 -fdump-tree-profile_estimate-blocks-details" } */
+/* { dg-options "-O2 -fdump-tree-profile_estimate" } */
 
-void g(void);
-void h(void);
+int v1, v2;
 void f(int x, int y)
 {
   if (x) goto A;
@@ -10,11 +9,11 @@ void f(int x, int y)
   return;
 
  A: __attribute__((cold))
-  g();
+  v1 = x;
   return;
 
  B: __attribute__((hot))
-  h();
+  v2 = y;
   return;
 }
 

gcc/testsuite/gcc.dg/tree-ssa/vrp24.c

 /* { dg-do compile } */
-/* { dg-options "-O2 -fno-tree-forwprop -fdump-tree-vrp1-details" } */
+/* { dg-options "-O2 -fno-tree-forwprop -fdump-tree-vrp1-details -fdump-tree-optimized" } */
 
 
 struct rtx_def;
@@ -86,10 +86,8 @@ L7:
 
 /* The first n_sets > 0 test can be simplfiied into n_sets == 1 since
    n_sets can only have the values [0, 1] as it's the result of a
-   boolean operation.
+   boolean operation.  */
 
-   The second n_sets > 0 test can also be simplified into n_sets == 1
-   as the only way to reach the tests is when n_sets <= 1 and the only
-   value which satisfies both conditions is n_sets == 1.  */
-/* { dg-final { scan-tree-dump-times "Simplified relational" 2 "vrp1" } } */
+/* { dg-final { scan-tree-dump-times "Simplified relational" 1 "vrp1" } } */
+/* { dg-final { scan-tree-dump-times "if " 4 "optimized" } } */