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

runtime/vm/object.cc

Index: runtime/vm/object.cc
===================================================================
--- runtime/vm/object.cc	(revision 11621)
+++ runtime/vm/object.cc	(working copy)
@@ -3909,7 +3909,8 @@
 
 bool Function::is_optimizable() const {
   return OptimizableBit::decode(raw_ptr()->kind_tag_) &&
-         (script() != Script::null());
+         (script() != Script::null()) &&
+         !is_native();
 }
 
 
@@ -6654,13 +6655,14 @@
 
 const char* PcDescriptors::KindAsStr(intptr_t index) const {
   switch (DescriptorKind(index)) {
-    case PcDescriptors::kDeopt:      return "deopt   ";
-    case PcDescriptors::kDeoptIndex: return "deopt-ix";
-    case PcDescriptors::kPatchCode:  return "patch   ";
-    case PcDescriptors::kIcCall:     return "ic-call ";
-    case PcDescriptors::kFuncCall:   return "fn-call ";
-    case PcDescriptors::kReturn:     return "return  ";
-    case PcDescriptors::kOther:      return "other   ";
+    case PcDescriptors::kDeoptBefore: return "deopt-before ";
+    case PcDescriptors::kDeoptAfter:  return "deopt-after  ";
+    case PcDescriptors::kDeoptIndex:  return "deopt-ix     ";
+    case PcDescriptors::kPatchCode:   return "patch        ";
+    case PcDescriptors::kIcCall:      return "ic-call      ";
+    case PcDescriptors::kFuncCall:    return "fn-call      ";
+    case PcDescriptors::kReturn:      return "return       ";
+    case PcDescriptors::kOther:       return "other        ";
   }
   UNREACHABLE();
   return "";
@@ -6742,7 +6744,7 @@
     // 'deopt_id' is set for kDeopt and kIcCall and must be unique for one kind.
     intptr_t deopt_id = Isolate::kNoDeoptId;
     if (check_ids) {
-      if ((DescriptorKind(i) == PcDescriptors::kDeopt) ||
+      if ((DescriptorKind(i) == PcDescriptors::kDeoptBefore) ||
           (DescriptorKind(i) == PcDescriptors::kIcCall)) {
         deopt_id = DeoptId(i);
       }
@@ -7289,18 +7291,32 @@
 }
 
 
-uword Code::GetDeoptPcAtDeoptId(intptr_t deopt_id) const {
+uword Code::GetPcForDeoptId(intptr_t deopt_id, PcDescriptors::Kind kind) const {
   const PcDescriptors& descriptors = PcDescriptors::Handle(pc_descriptors());
   for (intptr_t i = 0; i < descriptors.Length(); i++) {
     if ((descriptors.DeoptId(i) == deopt_id) &&
-        (descriptors.DescriptorKind(i) == PcDescriptors::kDeopt)) {
-      return descriptors.PC(i);
+        (descriptors.DescriptorKind(i) == kind)) {
+      uword pc = descriptors.PC(i);
+      ASSERT((EntryPoint() < pc) && (pc < (EntryPoint() + Size())));
+      return pc;
     }
   }
   return 0;
 }
 
 
+uword Code::GetDeoptBeforePcAtDeoptId(intptr_t deopt_id) const {
+  ASSERT(!is_optimized());
+  return GetPcForDeoptId(deopt_id, PcDescriptors::kDeoptBefore);
+}
+
+
+uword Code::GetDeoptAfterPcAtDeoptId(intptr_t deopt_id) const {
+  ASSERT(!is_optimized());
+  return GetPcForDeoptId(deopt_id, PcDescriptors::kDeoptAfter);
+}
+
+
 const char* Code::ToCString() const {
   const char* kFormat = "Code entry:0x%d";
   intptr_t len = OS::SNPrint(NULL, 0, kFormat, EntryPoint()) + 1;