[turbofan] First shot at eager deoptimization in Turbofan.

src/compiler/instruction-selector.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/instruction-selector.h"
 
 #include <limits>
 
 #include "src/compiler/instruction-selector-impl.h"
 #include "src/compiler/node-matchers.h"
@@ skipping 527 matching lines @@
         case_values[index] = value;
         if (min_value > value) min_value = value;
         if (max_value < value) max_value = value;
       }
       DCHECK_LE(min_value, max_value);
       return VisitSwitch(input, default_branch, case_branches, case_values,
                          case_count, min_value, max_value);
     }
     case BasicBlock::kReturn: {
       // If the result itself is a return, return its input.
-      Node* value = (input != NULL && input->opcode() == IrOpcode::kReturn)
+      Node* value = (input != nullptr && input->opcode() == IrOpcode::kReturn)
                         ? input->InputAt(0)
                         : input;
       return VisitReturn(value);
     }
+    case BasicBlock::kDeoptimize: {
+      // If the result itself is a return, return its input.
+      Node* value =
+          (input != nullptr && input->opcode() == IrOpcode::kDeoptimize)
+              ? input->InputAt(0)
+              : input;
+      return VisitDeoptimize(value);
+    }
     case BasicBlock::kThrow:
       DCHECK_EQ(IrOpcode::kThrow, input->opcode());
       return VisitThrow(input->InputAt(0));
     case BasicBlock::kNone: {
       // TODO(titzer): exit block doesn't have control.
       DCHECK_NULL(input);
       break;
     }
     default:
       UNREACHABLE();
@@ skipping 520 matching lines @@
   if (value != NULL) {
     Emit(kArchRet, g.NoOutput(),
          g.UseLocation(value, linkage()->GetReturnLocation(),
                        linkage()->GetReturnType()));
   } else {
     Emit(kArchRet, g.NoOutput());
   }
 }
 
 
+void InstructionSelector::VisitDeoptimize(Node* value) {
+  DCHECK(FLAG_turbo_deoptimization);
+
+  OperandGenerator g(this);
+
+  FrameStateDescriptor* desc = GetFrameStateDescriptor(value);
+  size_t arg_count = desc->GetTotalSize() + 1;  // Include deopt id.
+
+  InstructionOperandVector args(instruction_zone());
+  args.reserve(arg_count);
+
+  InstructionSequence::StateId state_id =
+      sequence()->AddFrameStateDescriptor(desc);
+  args.push_back(g.TempImmediate(state_id.ToInt()));
+
+  AddFrameStateInputs(value, &args, desc);
+
+  DCHECK_EQ(args.size(), arg_count);
+
+  Emit(kArchDeoptimize, 0, nullptr, arg_count, &args.front(), 0, nullptr);
+}
+
+
 void InstructionSelector::VisitThrow(Node* value) {
   OperandGenerator g(this);
   Emit(kArchNop, g.NoOutput());  // TODO(titzer)
 }
 
 
 void InstructionSelector::FillTypeVectorFromStateValues(
     ZoneVector<MachineType>* types, Node* state_values) {
   DCHECK(state_values->opcode() == IrOpcode::kStateValues);
   int count = state_values->InputCount();
@@ skipping 113 matching lines @@
 MachineOperatorBuilder::Flags
 InstructionSelector::SupportedMachineOperatorFlags() {
   return MachineOperatorBuilder::Flag::kNoFlags;
 }
 
 #endif  // !V8_TURBOFAN_BACKEND
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8