Deoptimization can occur at Dart calls (includes native calls to C) but not at runtime calls. This …

runtime/vm/deopt_instructions.cc

 // Copyright (c) 2012, 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_macros.h"
 #include "vm/intermediate_language.h"
 #include "vm/locations.h"
 #include "vm/parser.h"
@@ skipping 82 matching lines @@
     return chars;
   }
 
   void Execute(DeoptimizationContext* deopt_context, intptr_t to_index) {
     Function& function = Function::Handle(deopt_context->isolate());
     function ^= deopt_context->ObjectAt(object_table_index_);
     Smi& deopt_id_as_smi = Smi::Handle(deopt_context->isolate());
     deopt_id_as_smi ^= deopt_context->ObjectAt(object_table_index_ + 1);
     const Code& code =
         Code::Handle(deopt_context->isolate(), function.unoptimized_code());
-    uword continue_at_pc = code.GetDeoptPcAtDeoptId(deopt_id_as_smi.Value());
+    uword continue_at_pc =
+        code.GetDeoptBeforePcAtDeoptId(deopt_id_as_smi.Value());

[siva, 2012/08/30 01:37:30]

Ditto question about unoptimized code having a DeoptBefore entry?

[srdjan, 2012/08/30 17:16:16]

Ditto answer

     intptr_t* to_addr = deopt_context->GetToFrameAddressAt(to_index);
     *to_addr = continue_at_pc;
   }
 
  private:
   const intptr_t object_table_index_;
 
   DISALLOW_COPY_AND_ASSIGN(DeoptRetAddrInstr);
 };
 
@@ skipping 230 matching lines @@
   const intptr_t len = instructions_.length();
   const DeoptInfo& deopt_info = DeoptInfo::Handle(DeoptInfo::New(len));
   for (intptr_t i = 0; i < len; i++) {
     DeoptInstr* instr = instructions_[i];
     deopt_info.SetAt(i, instr->kind(), instr->from_index());
   }
   return deopt_info.raw();
 }
 
 }  // namespace dart