Add deoptimization history to optimized functions.

runtime/vm/deopt_instructions.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/deopt_instructions.h"
 
 #include "vm/assembler.h"
 #include "vm/code_patcher.h"
 #include "vm/intermediate_language.h"
 #include "vm/locations.h"
 #include "vm/parser.h"
 #include "vm/stack_frame.h"
 
 namespace dart {
 
 DEFINE_FLAG(bool, compress_deopt_info, true,
             "Compress the size of the deoptimization info for optimized code.");
 DECLARE_FLAG(bool, trace_deoptimization);
+DECLARE_FLAG(bool, trace_deoptimization_verbose);
 
 DeoptimizationContext::DeoptimizationContext(intptr_t* to_frame_start,
                                              intptr_t to_frame_size,
                                              const Array& object_table,
                                              intptr_t num_args,
                                              DeoptReasonId deopt_reason)
     : object_table_(object_table),
       to_frame_(to_frame_start),
       to_frame_size_(to_frame_size),
       from_frame_(NULL),
@@ skipping 247 matching lines @@
     uword pc = code.GetPcForDeoptId(deopt_id_, PcDescriptors::kIcCall);
     if (pc != 0) {
       // If the deoptimization happened at an IC call, update the IC data
       // to avoid repeated deoptimization at the same site next time around.
       ICData& ic_data = ICData::Handle();
       CodePatcher::GetInstanceCallAt(pc, code, &ic_data, NULL);
       if (!ic_data.IsNull()) {
         ic_data.set_deopt_reason(deopt_context->deopt_reason());
       }
     }
+
+    const Array& deopt_history = Array::Handle(function.deopt_history());
+    ASSERT(!deopt_history.IsNull());
+    intptr_t count = function.deoptimization_counter();
+    ASSERT(count > 0);
+    if (count <= deopt_history.Length()) {
+      deopt_history.SetAt(count - 1, Smi::Handle(Smi::New(deopt_id_)));
+      if (FLAG_trace_deoptimization_verbose) {
+        OS::Print("  adding id %"Pd" to history at %"Pd"\n",
+                  deopt_id_, count - 1);
+      }
+    }
   }
 
   intptr_t object_table_index() const { return object_table_index_; }
   intptr_t deopt_id() const { return deopt_id_; }
 
  private:
   static const intptr_t kFieldWidth = kBitsPerWord / 2;
   class ObjectTableIndex : public BitField<intptr_t, 0, kFieldWidth> { };
   class DeoptId : public BitField<intptr_t, kFieldWidth, kFieldWidth> { };
 
@@ skipping 800 matching lines @@
                           Smi* offset,
                           DeoptInfo* info,
                           Smi* reason) {
   intptr_t i = index * kEntrySize;
   *offset ^= table.At(i);
   *info ^= table.At(i + 1);
   *reason ^= table.At(i + 2);
 }
 
 }  // namespace dart