[gcc(refs/users/kubaneko/heads/histogram)] started with conversion to parametric histograms

[Ondrej Kubanek <kubaneko@gcc.gnu.org>]

https://gcc.gnu.org/g:ecf3c41ca0dd4b6cf8319b2a444e8b6e71d5c25f

commit ecf3c41ca0dd4b6cf8319b2a444e8b6e71d5c25f
Author: kubaneko <kubanek0ondrej@gmail.com>
Date:   Sat Dec 31 21:31:38 2022 +0000

    started with conversion to parametric histograms

Diff:
---
 gcc/cfgloop.h             | 31 ++++++++++++++-----------------
 gcc/params.opt            |  8 ++++++++
 gcc/profile.cc            |  2 +-
 gcc/value-prof.cc         | 13 ++++++++-----
 libgcc/libgcov-profiler.c |  9 +++++++++
 5 files changed, 40 insertions(+), 23 deletions(-)

diff --git a/gcc/cfgloop.h b/gcc/cfgloop.h
index 94a18e56e5e..8ec6bb03ad1 100644
--- a/gcc/cfgloop.h
+++ b/gcc/cfgloop.h
@@ -98,25 +98,22 @@ struct GTY(()) histogram_counters{
     gcov_type sum;
     int histogram_size;
     gcov_type hist[69];
-
-    // need to think about overflows
-    // quantil function for the distribution
-    // returns index under which is koef part of the distribution
-    // int quantil(float koef){
-    //     gcc_assert(0<koef && koef<=1);
-    //     gcov_type quant=0;
-    //     int i=0;
-    //     for (;i<69;++i) {
-    //         if (quant+hist[i]<koef*sum) {
-    //             quant+=hist[i];
-    //         } else {
-    //             break;
-    //         }
-    //     }
-    //     return i;
-    // };
 };
 
+// quantil function for the distribution
+// int quantil_asdf(float koef, histogram_counters* count){
+//     gcc_assert(0<koef && koef<=1);
+//     gcov_type quant=0;
+//     int i=0;
+//     for (;i<69;++i) {
+//         if (quant+count->hist[i]<koef*count->sum) {
+//             quant+=count->hist[i];
+//         } else {
+//             break;
+//         }
+//     }
+//     return i;
+// };
 
 typedef class loop *loop_p;
 
diff --git a/gcc/params.opt b/gcc/params.opt
index 41d8bef245e..804c5cdbe76 100644
--- a/gcc/params.opt
+++ b/gcc/params.opt
@@ -874,6 +874,14 @@ Min. ratio of insns to mem ops to enable prefetching in a loop.
 Common Joined UInteger Var(param_prefetch_minimum_stride) Init(-1) Param Optimization
 The minimum constant stride beyond which we should use prefetch hints for.
 
+-param=profile-histogram-size=
+Common Joined UInteger Var(param_profile_histogram_size) Init(69) Param Optimization
+Total size of the histogram counter for profile feedback.
+
+-param=profile-histogram-size-lin=
+Common Joined UInteger Var(param_profile_histogram_size_lin) Init(8) Param Optimization
+Size of the linear portion of the histogram counter for profile feedback.
+
 -param=profile-func-internal-id=
 Common Joined UInteger Var(param_profile_func_internal_id) IntegerRange(0, 1) Param
 Use internal function id in profile lookup.
diff --git a/gcc/profile.cc b/gcc/profile.cc
index 6e99a6501c3..5a6cedfaaec 100644
--- a/gcc/profile.cc
+++ b/gcc/profile.cc
@@ -930,7 +930,7 @@ compute_value_histograms (histogram_values values, unsigned cfg_checksum,
         if (act_count[t]){
            lp->counters=ggc_alloc<histogram_counters>();
            gcov_type sum=0;
-           for (int i=0;i<69;++i){
+           for (int i=0;i<param_profile_histogram_size;++i){
                lp->counters->hist[i]=act_count[t][i];
                sum+=act_count[t][i];
            }
diff --git a/gcc/value-prof.cc b/gcc/value-prof.cc
index d81b210b068..133ed62118a 100644
--- a/gcc/value-prof.cc
+++ b/gcc/value-prof.cc
@@ -265,17 +265,20 @@ dump_histogram_value (FILE *dump_file, histogram_value hist)
       break;
     case HIST_TYPE_HISTOGRAM:
       if (hist->hvalue.counters){
-        for (int i=0; i<=8; ++i){
+        for (int i=0; i<=param_profile_histogram_size_lin; ++i){
   	  fprintf (dump_file, "Histogram counter histogram%" PRId64
 	     ":%" PRId64 ".\n",
 	     (int64_t) i,
 	     (int64_t) hist->hvalue.counters[i]);
         }
-        for (int64_t i=4; i<64; ++i){
+        int lin2_log=floor_log2 (param_profile_histogram_size_lin);
+        for (int64_t i=lin2_log;
+                i<param_profile_histogram_size-param_profile_histogram_size_lin+lin2_log;
+        ++i){
   	  fprintf (dump_file, "Histogram counter histogram%" PRId64
 	     ":%" PRId64 ".\n",
 	     (int64_t) 1>>i,
-	     (int64_t) hist->hvalue.counters[5+i]);
+	     (int64_t) hist->hvalue.counters[(param_profile_histogram_size_lin-lin2_log)+i]);
         }
       }
       break;
@@ -397,7 +400,7 @@ stream_in_histogram_value (class lto_input_block *ib, gimple *stmt)
 	  break;
 
     case HIST_TYPE_HISTOGRAM:
-	  ncounters = 69;
+	  ncounters = param_profile_histogram_size;
 	  break;
 	case HIST_TYPE_POW2:
 	case HIST_TYPE_AVERAGE:
@@ -1998,7 +2001,7 @@ gimple_find_values_to_profile (histogram_values *values)
 	  break;
 
 	case HIST_TYPE_HISTOGRAM:
-	  hist->n_counters = 69;
+	  hist->n_counters = param_profile_histogram_size;
 	  break;
 
 	default:
diff --git a/libgcc/libgcov-profiler.c b/libgcc/libgcov-profiler.c
index 5469276f8a7..739a30043c0 100644
--- a/libgcc/libgcov-profiler.c
+++ b/libgcc/libgcov-profiler.c
@@ -65,6 +65,15 @@ __gcov_histogram_profiler (gcov_type *counters, gcov_type value)
   }
 }
 
+//  if (value>=0 && value<param_profile_histogram_size_lin){
+//    counters[value]++;
+//  }else{
+//    gcc_assert(value>0);
+//    int pow2=floor_log2(value);
+//    counters[pow2+(param_profile_histogram_size_lin-floor_log2
+//            (param_profile_histogram_size_lin))]++;
+//  }
+
 #endif