[turbofan] Introduce lazy bailout, masked as a call.

src/compiler/ast-graph-builder.cc

 // Copyright 2014 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/ast-graph-builder.h"
 
 #include "src/compiler.h"
 #include "src/compiler/ast-loop-assignment-analyzer.h"
 #include "src/compiler/control-builders.h"
 #include "src/compiler/js-type-feedback.h"
@@ skipping 1392 matching lines @@
   try_control.BeginTry();
   {
     ControlScopeForCatch scope(this, &try_control);
     STATIC_ASSERT(TryBlockConstant::kElementCount == 1);
     environment()->Push(current_context());
     Visit(stmt->try_block());
     environment()->Pop();
   }
   try_control.EndTry();
 
-  // TODO(mstarzinger): We are only using a runtime call to get a lazy bailout
-  // point, there is no need to really emit an actual call. Optimize this!
-  Node* guard = NewNode(javascript()->CallRuntime(Runtime::kMaxSmi, 0));
-  PrepareFrameState(guard, stmt->HandlerId());
+  // Insert lazy bailout point.
+  // TODO(mstarzinger): We are only using a 'call' to get a lazy bailout
+  // point. Ideally, we whould not re-enter optimized code when deoptimized
+  // lazily. Tracked by issue v8:4195.
+  NewNode(common()->LazyBailout(),
+          jsgraph()->ZeroConstant(),                      // dummy target.
+          environment()->Checkpoint(stmt->HandlerId()));  // frame state.
 
   // Clear message object as we enter the catch block.
   Node* the_hole = jsgraph()->TheHoleConstant();
   BuildStoreExternal(message_object, kMachAnyTagged, the_hole);
 
   // Create a catch scope that binds the exception.
   Node* exception = try_control.GetExceptionNode();
   Handle<String> name = stmt->variable()->name();
   const Operator* op = javascript()->CreateCatchContext(name);
   Node* context = NewNode(op, exception, GetFunctionClosureForContext());
@@ skipping 27 matching lines @@
   try_control.BeginTry();
   {
     ControlScopeForFinally scope(this, commands, &try_control);
     STATIC_ASSERT(TryBlockConstant::kElementCount == 1);
     environment()->Push(current_context());
     Visit(stmt->try_block());
     environment()->Pop();
   }
   try_control.EndTry(commands->GetFallThroughToken(), fallthrough_result);
 
-  // TODO(mstarzinger): We are only using a runtime call to get a lazy bailout
-  // point, there is no need to really emit an actual call. Optimize this!
-  Node* guard = NewNode(javascript()->CallRuntime(Runtime::kMaxSmi, 0));
-  PrepareFrameState(guard, stmt->HandlerId());
+  // Insert lazy bailout point.
+  // TODO(mstarzinger): We are only using a 'call' to get a lazy bailout
+  // point. Ideally, we whould not re-enter optimized code when deoptimized
+  // lazily. Tracked by issue v8:4195.
+  NewNode(common()->LazyBailout(),
+          jsgraph()->ZeroConstant(),                      // dummy target.
+          environment()->Checkpoint(stmt->HandlerId()));  // frame state.
 
   // The result value semantics depend on how the block was entered:
   //  - ReturnStatement: It represents the return value being returned.
   //  - ThrowStatement: It represents the exception being thrown.
   //  - BreakStatement/ContinueStatement: Filled with the hole.
   //  - Falling through into finally-block: Filled with the hole.
   Node* result = try_control.GetResultValueNode();
   Node* token = try_control.GetDispatchTokenNode();
 
   // The result value, dispatch token and message is expected on the operand
@@ skipping 2807 matching lines @@
     // Phi does not exist yet, introduce one.
     value = NewPhi(inputs, value, control);
     value->ReplaceInput(inputs - 1, other);
   }
   return value;
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8