Implement N disk counters for single value and indirect call counters.

2019-06-10  Martin Liska  <mliska@suse.cz>

	* gcov-io.h (GCOV_DISK_SINGLE_VALUES): New.
	(GCOV_SINGLE_VALUE_COUNTERS): Likewise.
	* ipa-profile.c (ipa_profile_generate_summary):
	Use get_most_common_single_value.
	* tree-profile.c (gimple_init_gcov_profiler):
	Instrument with __gcov_one_value_profiler_v2
	and __gcov_indirect_call_profiler_v4.
	* value-prof.c (dump_histogram_value):
	Print all values for HIST_TYPE_SINGLE_VALUE.
	(stream_out_histogram_value): Update assert for
	N values.
	(stream_in_histogram_value): Set number of
	counters for HIST_TYPE_SINGLE_VALUE.
	(get_most_common_single_value): New.
	(gimple_divmod_fixed_value_transform):
	Use get_most_common_single_value.
	(gimple_ic_transform): Likewise.
	(gimple_stringops_transform): Likewise.
	(gimple_find_values_to_profile): Set number
	of counters for HIST_TYPE_SINGLE_VALUE.
	* value-prof.h (get_most_common_single_value):
	New.
2019-06-10  Martin Liska  <mliska@suse.cz>

	* Makefile.in: Add __gcov_one_value_profiler_v2,
	__gcov_one_value_profiler_v2_atomic and
	__gcov_indirect_call_profiler_v4.
	* libgcov-merge.c (__gcov_merge_single): Change
	function signature.
	(merge_single_value_set): New.
	* libgcov-profiler.c (__gcov_one_value_profiler_body):
	Update functionality.
	(__gcov_one_value_profiler): Remove.
	(__gcov_one_value_profiler_v2): ... this.
	(__gcov_one_value_profiler_atomic): Rename to ...
	(__gcov_one_value_profiler_v2_atomic): this.
	(__gcov_indirect_call_profiler_v3): Rename to ...
	(__gcov_indirect_call_profiler_v4): ... this.
	* libgcov.h (__gcov_one_value_profiler): Remove.
	(__gcov_one_value_profiler_atomic): Remove.
	(__gcov_one_value_profiler_v2_atomic): New.
	(__gcov_indirect_call_profiler_v3): Remove.
	(__gcov_one_value_profiler_v2): New.
	(__gcov_indirect_call_profiler_v4): New.
	(gcov_get_counter_ignore_scaling): New function.

From-SVN: r272106

5 files changed, 126 insertions, 49 deletions

diff --git a/libgcc/ChangeLog b/libgcc/ChangeLog
index 7ef347a..669041e 100644
--- a/libgcc/ChangeLog
+++ b/libgcc/ChangeLog
@@ -1,3 +1,27 @@
+2019-06-10  Martin Liska  <mliska@suse.cz>
+
+	* Makefile.in: Add __gcov_one_value_profiler_v2,
+	__gcov_one_value_profiler_v2_atomic and
+	__gcov_indirect_call_profiler_v4.
+	* libgcov-merge.c (__gcov_merge_single): Change
+	function signature.
+	(merge_single_value_set): New.
+	* libgcov-profiler.c (__gcov_one_value_profiler_body):
+	Update functionality.
+	(__gcov_one_value_profiler): Remove.
+	(__gcov_one_value_profiler_v2): ... this.
+	(__gcov_one_value_profiler_atomic): Rename to ...
+	(__gcov_one_value_profiler_v2_atomic): this.
+	(__gcov_indirect_call_profiler_v3): Rename to ...
+	(__gcov_indirect_call_profiler_v4): ... this.
+	* libgcov.h (__gcov_one_value_profiler): Remove.
+	(__gcov_one_value_profiler_atomic): Remove.
+	(__gcov_one_value_profiler_v2_atomic): New.
+	(__gcov_indirect_call_profiler_v3): Remove.
+	(__gcov_one_value_profiler_v2): New.
+	(__gcov_indirect_call_profiler_v4): New.
+	(gcov_get_counter_ignore_scaling): New function.
+
 2019-06-07  Martin Liska  <mliska@suse.cz>
 
 	* Makefile.in: Remove usage of
diff --git a/libgcc/Makefile.in b/libgcc/Makefile.in
index fb77881..33b8380 100644
--- a/libgcc/Makefile.in
+++ b/libgcc/Makefile.in
@@ -893,13 +893,13 @@ LIBGCOV_PROFILER = _gcov_interval_profiler				\
 	_gcov_interval_profiler_atomic					\
 	_gcov_pow2_profiler						\
 	_gcov_pow2_profiler_atomic					\
-	_gcov_one_value_profiler					\
-	_gcov_one_value_profiler_atomic					\
+	_gcov_one_value_profiler_v2					\
+	_gcov_one_value_profiler_v2_atomic					\
 	_gcov_average_profiler						\
 	_gcov_average_profiler_atomic					\
 	_gcov_ior_profiler						\
 	_gcov_ior_profiler_atomic					\
-	_gcov_indirect_call_profiler_v3					\
+	_gcov_indirect_call_profiler_v4					\
 	_gcov_time_profiler
 LIBGCOV_INTERFACE = _gcov_dump _gcov_flush _gcov_fork			\
 	_gcov_execl _gcov_execlp					\
diff --git a/libgcc/libgcov-merge.c b/libgcc/libgcov-merge.c
index 702a69f..4241634 100644
--- a/libgcc/libgcov-merge.c
+++ b/libgcc/libgcov-merge.c
@@ -34,8 +34,9 @@ void __gcov_merge_add (gcov_type *counters  __attribute__ ((unused)),
 #endif
 
 #ifdef L_gcov_merge_single
-void __gcov_merge_single (gcov_type *counters  __attribute__ ((unused)),
-                          unsigned n_counters __attribute__ ((unused))) {}
+void __gcov_merge_single (gcov_type *counters  __attribute__ ((unused)))
+{
+}
 #endif
 
 #else
@@ -85,40 +86,72 @@ __gcov_merge_time_profile (gcov_type *counters, unsigned n_counters)
 #endif /* L_gcov_merge_time_profile */
 
 #ifdef L_gcov_merge_single
+
+static void
+merge_single_value_set (gcov_type *counters)
+{
+  unsigned j;
+  gcov_type value, counter;
+
+  /* First value is number of total executions of the profiler.  */
+  gcov_type all = gcov_get_counter_ignore_scaling (-1);
+  counters[0] += all;
+  ++counters;
+
+  for (unsigned i = 0; i < GCOV_DISK_SINGLE_VALUES; i++)
+    {
+      value = gcov_get_counter_target ();
+      counter = gcov_get_counter_ignore_scaling (-1);
+
+      if (counter == -1)
+	{
+	  counters[1] = -1;
+	  /* We can't return as we need to read all counters.  */
+	  continue;
+	}
+      else if (counter == 0 || counters[1] == -1)
+	{
+	  /* We can't return as we need to read all counters.  */
+	  continue;
+	}
+
+      for (j = 0; j < GCOV_DISK_SINGLE_VALUES; j++)
+	{
+	  if (counters[2 * j] == value)
+	    {
+	      counters[2 * j + 1] += counter;
+	      break;
+	    }
+	  else if (counters[2 * j + 1] == 0)
+	    {
+	      counters[2 * j] = value;
+	      counters[2 * j + 1] = counter;
+	      break;
+	    }
+	}
+
+      /* We haven't found a free slot for the value, mark overflow.  */
+      if (j == GCOV_DISK_SINGLE_VALUES)
+	counters[1] = -1;
+    }
+}
+
 /* The profile merging function for choosing the most common value.
    It is given an array COUNTERS of N_COUNTERS old counters and it
    reads the same number of counters from the gcov file.  The counters
-   are split into 3-tuples where the members of the tuple have
+   are split into pairs where the members of the tuple have
    meanings:
 
    -- the stored candidate on the most common value of the measured entity
    -- counter
-   -- total number of evaluations of the value  */
+   */
 void
 __gcov_merge_single (gcov_type *counters, unsigned n_counters)
 {
-  unsigned i, n_measures;
-  gcov_type value, counter, all;
+  gcc_assert (!(n_counters % GCOV_SINGLE_VALUE_COUNTERS));
 
-  gcc_assert (!(n_counters % 3));
-  n_measures = n_counters / 3;
-  for (i = 0; i < n_measures; i++, counters += 3)
-    {
-      value = gcov_get_counter_target ();
-      counter = gcov_get_counter ();
-      all = gcov_get_counter ();
-
-      if (counters[0] == value)
-        counters[1] += counter;
-      else if (counter > counters[1])
-        {
-          counters[0] = value;
-          counters[1] = counter - counters[1];
-        }
-      else
-        counters[1] -= counter;
-      counters[2] += all;
-    }
+  for (unsigned i = 0; i < (n_counters / GCOV_SINGLE_VALUE_COUNTERS); i++)
+    merge_single_value_set (counters + (i * GCOV_SINGLE_VALUE_COUNTERS));
 }
 #endif /* L_gcov_merge_single */
 
diff --git a/libgcc/libgcov-profiler.c b/libgcc/libgcov-profiler.c
index 40f0858..9ba65b9 100644
--- a/libgcc/libgcov-profiler.c
+++ b/libgcc/libgcov-profiler.c
@@ -112,40 +112,37 @@ __gcov_pow2_profiler_atomic (gcov_type *counters, gcov_type value)
    COUNTERS[1] is decremented.  Otherwise COUNTERS[1] is set to one and
    VALUE is stored to COUNTERS[0].  This algorithm guarantees that if this
    function is called more than 50% of the time with one value, this value
-   will be in COUNTERS[0] in the end.
-
-   In any case, COUNTERS[2] is incremented.  If USE_ATOMIC is set to 1,
-   COUNTERS[2] is updated with an atomic instruction.  */
+   will be in COUNTERS[0] in the end.  */
 
 static inline void
 __gcov_one_value_profiler_body (gcov_type *counters, gcov_type value,
 				int use_atomic)
 {
-  if (value == counters[0])
-    counters[1]++;
-  else if (counters[1] == 0)
+  if (value == counters[1])
+    counters[2]++;
+  else if (counters[2] == 0)
     {
-      counters[1] = 1;
-      counters[0] = value;
+      counters[2] = 1;
+      counters[1] = value;
     }
   else
-    counters[1]--;
+    counters[2]--;
 
   if (use_atomic)
-    __atomic_fetch_add (&counters[2], 1, __ATOMIC_RELAXED);
+    __atomic_fetch_add (&counters[0], 1, __ATOMIC_RELAXED);
   else
-    counters[2]++;
+    counters[0]++;
 }
 
-#ifdef L_gcov_one_value_profiler
+#ifdef L_gcov_one_value_profiler_v2
 void
-__gcov_one_value_profiler (gcov_type *counters, gcov_type value)
+__gcov_one_value_profiler_v2 (gcov_type *counters, gcov_type value)
 {
   __gcov_one_value_profiler_body (counters, value, 0);
 }
 #endif
 
-#if defined(L_gcov_one_value_profiler_atomic) && GCOV_SUPPORTS_ATOMIC
+#if defined(L_gcov_one_value_profiler_v2_atomic) && GCOV_SUPPORTS_ATOMIC
 
 /* Update one value profilers (COUNTERS) for a given VALUE.
 
@@ -157,13 +154,13 @@ __gcov_one_value_profiler (gcov_type *counters, gcov_type value)
    https://gcc.gnu.org/ml/gcc-patches/2016-08/msg00024.html.  */
 
 void
-__gcov_one_value_profiler_atomic (gcov_type *counters, gcov_type value)
+__gcov_one_value_profiler_v2_atomic (gcov_type *counters, gcov_type value)
 {
   __gcov_one_value_profiler_body (counters, value, 1);
 }
 #endif
 
-#ifdef L_gcov_indirect_call_profiler_v3
+#ifdef L_gcov_indirect_call_profiler_v4
 
 /* These two variables are used to actually track caller and callee.  Keep
    them in TLS memory so races are not common (they are written to often).
@@ -185,7 +182,7 @@ struct indirect_call_tuple __gcov_indirect_call;
 
 /* Tries to determine the most common value among its inputs. */
 void
-__gcov_indirect_call_profiler_v3 (gcov_type value, void* cur_func)
+__gcov_indirect_call_profiler_v4 (gcov_type value, void* cur_func)
 {
   /* If the C++ virtual tables contain function descriptors then one
      function may have multiple descriptors and we need to dereference
diff --git a/libgcc/libgcov.h b/libgcc/libgcov.h
index b4f1ec5..144b481 100644
--- a/libgcc/libgcov.h
+++ b/libgcc/libgcov.h
@@ -271,9 +271,9 @@ extern void __gcov_interval_profiler_atomic (gcov_type *, gcov_type, int,
 					     unsigned);
 extern void __gcov_pow2_profiler (gcov_type *, gcov_type);
 extern void __gcov_pow2_profiler_atomic (gcov_type *, gcov_type);
-extern void __gcov_one_value_profiler (gcov_type *, gcov_type);
-extern void __gcov_one_value_profiler_atomic (gcov_type *, gcov_type);
-extern void __gcov_indirect_call_profiler_v3 (gcov_type, void *);
+extern void __gcov_one_value_profiler_v2 (gcov_type *, gcov_type);
+extern void __gcov_one_value_profiler_v2_atomic (gcov_type *, gcov_type);
+extern void __gcov_indirect_call_profiler_v4 (gcov_type, void *);
 extern void __gcov_time_profiler (gcov_type *);
 extern void __gcov_time_profiler_atomic (gcov_type *);
 extern void __gcov_average_profiler (gcov_type *, gcov_type);
@@ -324,6 +324,29 @@ gcov_get_counter (void)
 #endif
 }
 
+/* Similar function as gcov_get_counter(), but do not scale
+   when read value is equal to IGNORE_SCALING.  */
+
+static inline gcov_type
+gcov_get_counter_ignore_scaling (gcov_type ignore_scaling)
+{
+#ifndef IN_GCOV_TOOL
+  /* This version is for reading count values in libgcov runtime:
+     we read from gcda files.  */
+
+  return gcov_read_counter ();
+#else
+  /* This version is for gcov-tool. We read the value from memory and
+     multiply it by the merge weight.  */
+
+  gcov_type v = gcov_read_counter_mem ();
+  if (v != ignore_scaling)
+    v *= gcov_get_merge_weight ();
+
+  return v;
+#endif
+}
+
 /* Similar function as gcov_get_counter(), but handles target address
    counters.  */