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
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 @@
    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 @@
    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 @@
 
 /* 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