[Interpreter] Adds support for throw to bytecode graph builder.

src/compiler/bytecode-graph-builder.cc

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/compiler/bytecode-graph-builder.h"
 
 #include "src/compiler/linkage.h"
 #include "src/compiler/operator-properties.h"
 #include "src/interpreter/bytecode-array-iterator.h"
 
@@ skipping 798 matching lines @@
   const Operator* call = javascript()->CallConstruct(
       static_cast<int>(arg_count) + 2, VectorSlotPair());
   Node* value = ProcessCallNewArguments(call, callee, first_arg, arg_count + 2);
   AddEmptyFrameStateInputs(value);
   environment()->BindAccumulator(value);
 }
 
 
 void BytecodeGraphBuilder::VisitThrow(
     const interpreter::BytecodeArrayIterator& iterator) {
-  UNIMPLEMENTED();
+  Node* value = environment()->LookupAccumulator();
+  NewNode(javascript()->CallRuntime(Runtime::kReThrow, 1), value);

[Michael Starzinger, 2015/11/26 17:27:45]

This should be Runtime::kThrow, not Runtime::kReThrow, otherwise the exception
message will not be created and the throw location won't be setup.

[Michael Starzinger, 2015/11/27 09:28:46]

I realized later that creating the exception message will require deoptimization
information, which we don't yet have for these graphs. So I would be fine with
keeping kReThrow here for now (until we have deopt info) but at least leave a
big TODO here.

[mythria, 2015/11/27 14:54:47]

Thanks for pointing this. We should use Runtime::kReThrow because interpreter
does not support deopt yet right? I just wanted to be explicit in the TODO
comment.

[Michael Starzinger, 2015/11/27 15:09:18]

Acknowledged. Yep, correct, TODO sounds good to me.

+  Node* control = NewNode(common()->Throw(), value);
+  UpdateControlDependencyToLeaveFunction(control);
+  environment()->BindAccumulator(value);
 }
 
 
 void BytecodeGraphBuilder::BuildBinaryOp(
     const Operator* js_op, const interpreter::BytecodeArrayIterator& iterator) {
   Node* left = environment()->LookupRegister(iterator.GetRegisterOperand(0));
   Node* right = environment()->LookupAccumulator();
   Node* node = NewNode(js_op, left, right);
 
   AddEmptyFrameStateInputs(node);
@@ skipping 422 matching lines @@
 
 void BytecodeGraphBuilder::UpdateControlDependencyToLeaveFunction(Node* exit) {
   if (environment()->IsMarkedAsUnreachable()) return;
   environment()->MarkAsUnreachable();
   exit_controls_.push_back(exit);
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8