We can throw an exception but we cannot deoptimize at a runtime call.

runtime/vm/intermediate_language_x64.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/globals.h"  // Needed here to get TARGET_ARCH_X64.
 #if defined(TARGET_ARCH_X64)
 
 #include "vm/intermediate_language.h"
 
 #include "lib/error.h"
@@ skipping 67 matching lines @@
       __ Bind(&not_yet_hot);
       __ Bind(&already_optimized);
     }
   }
   if (FLAG_trace_functions) {
     const Function& function =
         Function::ZoneHandle(compiler->parsed_function().function().raw());
     __ LoadObject(temp, function);
     __ pushq(result);  // Preserve result.
     __ pushq(temp);
-    compiler->GenerateCallRuntime(Isolate::kNoDeoptId,
-                                  0,
+    compiler->GenerateCallRuntime(0,
                                   kTraceFunctionExitRuntimeEntry,
                                   NULL);
     __ popq(temp);  // Remove argument.
     __ popq(result);  // Restore result.
   }
 #if defined(DEBUG)
   // TODO(srdjan): Fix for functions with finally clause.
   // A finally clause may leave a previously pushed return value if it
   // has its own return instruction. Method that have finally are currently
   // not optimized.
@@ skipping 111 matching lines @@
   if (!is_eliminated()) {
     // Check that the type of the value is allowed in conditional context.
     // Call the runtime if the object is not bool::true or bool::false.
     Label done;
     __ CompareObject(obj, compiler->bool_true());
     __ j(EQUAL, &done, Assembler::kNearJump);
     __ CompareObject(obj, compiler->bool_false());
     __ j(EQUAL, &done, Assembler::kNearJump);
 
     __ pushq(obj);  // Push the source object.
-    compiler->GenerateCallRuntime(deopt_id(),
-                                  token_pos(),
+    compiler->GenerateCallRuntime(token_pos(),
                                   kConditionTypeErrorRuntimeEntry,
                                   locs());
     // We should never return here.
     __ int3();
     __ Bind(&done);
   }
   ASSERT(obj == result);
 }
 
 
@@ skipping 10 matching lines @@
 
 void ArgumentDefinitionTestComp::EmitNativeCode(FlowGraphCompiler* compiler) {
   Register saved_args_desc = locs()->in(0).reg();
   Register result = locs()->out().reg();
 
   // Push the result place holder initialized to NULL.
   __ PushObject(Object::ZoneHandle());
   __ pushq(Immediate(Smi::RawValue(formal_parameter_index())));
   __ PushObject(formal_parameter_name());
   __ pushq(saved_args_desc);
-  compiler->GenerateCallRuntime(deopt_id(),
-                                token_pos(),
+  compiler->GenerateCallRuntime(token_pos(),
                                 kArgumentDefinitionTestRuntimeEntry,
                                 locs());
   __ Drop(3);
   __ popq(result);  // Pop bool result.
 }
 
 
 static Condition TokenKindToSmiCondition(Token::Kind kind) {
   switch (kind) {
     case Token::kEQ: return EQUAL;
@@ skipping 806 matching lines @@
   summary->set_out(Location::RegisterLocation(RAX));
   return summary;
 }
 
 
 void InstanceOfComp::EmitNativeCode(FlowGraphCompiler* compiler) {
   ASSERT(locs()->in(0).reg() == RAX);  // Value.
   ASSERT(locs()->in(1).reg() == RCX);  // Instantiator.
   ASSERT(locs()->in(2).reg() == RDX);  // Instantiator type arguments.
 
-  compiler->GenerateInstanceOf(deopt_id(),
-                               token_pos(),
+  compiler->GenerateInstanceOf(token_pos(),
                                type(),
                                negate_result(),
                                locs());
   ASSERT(locs()->out().reg() == RAX);
 }
 
 
 LocationSummary* CreateArrayComp::MakeLocationSummary() const {
   const intptr_t kNumInputs = 1;
   const intptr_t kNumTemps = 0;
@@ skipping 41 matching lines @@
   const Class& cls = Class::ZoneHandle(constructor().Owner());
   Register type_arguments = locs()->in(0).reg();
   Register instantiator_type_arguments = locs()->in(1).reg();
   Register result = locs()->out().reg();
 
   // Push the result place holder initialized to NULL.
   __ PushObject(Object::ZoneHandle());
   __ PushObject(cls);
   __ pushq(type_arguments);
   __ pushq(instantiator_type_arguments);
-  compiler->GenerateCallRuntime(deopt_id(),
-                                token_pos(),
+  compiler->GenerateCallRuntime(token_pos(),
                                 kAllocateObjectWithBoundsCheckRuntimeEntry,
                                 locs());
   // Pop instantiator type arguments, type arguments, and class.
   __ Drop(3);
   __ popq(result);  // Pop new instance.
 }
 
 
 LocationSummary* LoadVMFieldComp::MakeLocationSummary() const {
   return LocationSummary::Make(1,
@@ skipping 51 matching lines @@
     __ j(NOT_EQUAL, &type_arguments_uninstantiated, Assembler::kNearJump);
     __ cmpq(FieldAddress(instantiator_reg, TypeArguments::length_offset()),
             Immediate(Smi::RawValue(len)));
     __ j(EQUAL, &type_arguments_instantiated, Assembler::kNearJump);
     __ Bind(&type_arguments_uninstantiated);
   }
   // A runtime call to instantiate the type arguments is required.
   __ PushObject(Object::ZoneHandle());  // Make room for the result.
   __ PushObject(type_arguments());
   __ pushq(instantiator_reg);  // Push instantiator type arguments.
-  compiler->GenerateCallRuntime(deopt_id(),
-                                token_pos(),
+  compiler->GenerateCallRuntime(token_pos(),
                                 kInstantiateTypeArgumentsRuntimeEntry,
                                 locs());
   __ Drop(2);  // Drop instantiator and uninstantiated type arguments.
   __ popq(result_reg);  // Pop instantiated type arguments.
   __ Bind(&type_arguments_instantiated);
   ASSERT(instantiator_reg == result_reg);
   // 'result_reg': Instantiated type arguments.
 }
 
 
@@ skipping 153 matching lines @@
   return locs;
 }
 
 
 void CloneContextComp::EmitNativeCode(FlowGraphCompiler* compiler) {
   Register context_value = locs()->in(0).reg();
   Register result = locs()->out().reg();
 
   __ PushObject(Object::ZoneHandle());  // Make room for the result.
   __ pushq(context_value);
-  compiler->GenerateCallRuntime(deopt_id(),
-                                token_pos(),
+  compiler->GenerateCallRuntime(token_pos(),
                                 kCloneContextRuntimeEntry,
                                 locs());
   __ popq(result);  // Remove argument.
   __ popq(result);  // Get result (cloned context).
 }
 
 
 LocationSummary* CatchEntryComp::MakeLocationSummary() const {
   return LocationSummary::Make(0,
                                Location::NoLocation(),
@@ skipping 34 matching lines @@
 
 
 class CheckStackOverflowSlowPath : public SlowPathCode {
  public:
   explicit CheckStackOverflowSlowPath(CheckStackOverflowComp* computation)
       : computation_(computation) { }
 
   virtual void EmitNativeCode(FlowGraphCompiler* compiler) {
     __ Bind(entry_label());
     compiler->SaveLiveRegisters(computation_->locs());
-    compiler->GenerateCallRuntime(computation_->deopt_id(),
-                                  computation_->token_pos(),
+    compiler->GenerateCallRuntime(computation_->token_pos(),
                                   kStackOverflowRuntimeEntry,
                                   computation_->locs());
     compiler->RestoreLiveRegisters(computation_->locs());
     __ jmp(exit_label());
   }
 
  private:
   CheckStackOverflowComp* computation_;
 };
 
@@ skipping 796 matching lines @@
   }
   __ j(ABOVE_EQUAL, deopt);
 }
 
 
 }  // namespace dart
 
 #undef __
 
 #endif  // defined TARGET_ARCH_X64