[turbofan] Address the useless overflow bit materialization.

src/compiler/simplified-lowering.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/simplified-lowering.h"
 
 #include <limits>
 
 #include "src/address-map.h"
 #include "src/base/bits.h"
@@ skipping 1073 matching lines @@
       Node* effect = NodeProperties::GetEffectInput(node);
       ReplaceEffectControlUses(node, effect, control);
       node->TrimInputCount(new_op->ValueInputCount());
     } else {
       DCHECK_EQ(0, node->op()->ControlInputCount());
     }
 
     NodeProperties::ChangeOp(node, new_op);
   }
 
-  void ChangeToInt32OverflowOp(Node* node, const Operator* op) {
-    Node* effect = NodeProperties::GetEffectInput(node);
-    Node* control = NodeProperties::GetControlInput(node);
-    Node* arith = graph()->NewNode(op, node->InputAt(0), node->InputAt(1));
-    Node* overflow = graph()->NewNode(common()->Projection(1), arith);
-    effect =
-        graph()->NewNode(simplified()->CheckIf(), overflow, effect, control);
-    Node* value = graph()->NewNode(common()->Projection(0), arith);
-    ReplaceEffectControlUses(node, effect, control);
-    DeferReplacement(node, value);
+  void ChangeToInt32OverflowOp(Node* node, const Operator* new_op) {
+    NodeProperties::ChangeOp(node, new_op);
   }
 
   void VisitSpeculativeAdditiveOp(Node* node, Truncation truncation,
                                   SimplifiedLowering* lowering) {
     if (BothInputsAre(node, type_cache_.kSigned32OrMinusZero) &&
         NodeProperties::GetType(node)->Is(Type::Signed32())) {
       // int32 + int32 = int32   ==>   signed Int32Add/Sub
       VisitInt32Binop(node);
       if (lower()) ChangeToPureOp(node, Int32Op(node));
       return;
@@ skipping 907 matching lines @@
       case IrOpcode::kStateValues:
         return VisitStateValues(node);
 
       // The following opcodes are not produced before representation
       // inference runs, so we do not have any real test coverage.
       // Simply fail here.
       case IrOpcode::kChangeFloat64ToInt32:
       case IrOpcode::kChangeFloat64ToUint32:
       case IrOpcode::kTruncateInt64ToInt32:
       case IrOpcode::kChangeFloat32ToFloat64:
+      case IrOpcode::kCheckedInt32Add:
+      case IrOpcode::kCheckedInt32Sub:
       case IrOpcode::kCheckedUint32ToInt32:
       case IrOpcode::kCheckedFloat64ToInt32:
       case IrOpcode::kCheckedTaggedToInt32:
       case IrOpcode::kCheckedTaggedToFloat64:
       case IrOpcode::kPlainPrimitiveToWord32:
       case IrOpcode::kPlainPrimitiveToFloat64:
         FATAL("Representation inference: unsupported opcodes.");
         break;
 
       default:
@@ skipping 1015 matching lines @@
         isolate(), graph()->zone(), callable.descriptor(), 0, flags,
         Operator::kNoProperties);
     to_number_operator_.set(common()->Call(desc));
   }
   return to_number_operator_.get();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8