[turbofan] Optimize tagged conversion based on type.

src/compiler/verifier.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/verifier.h"
 
 #include <algorithm>
 #include <deque>
 #include <queue>
 #include <sstream>
@@ skipping 778 matching lines @@
     }
     case IrOpcode::kChangeTaggedToFloat64: {
       // Number /\ Tagged -> Number /\ UntaggedFloat64
       // TODO(neis): Activate once ChangeRepresentation works in typer.
       // Type* from = Type::Intersect(Type::Number(), Type::Tagged());
       // Type* to = Type::Intersect(Type::Number(), Type::UntaggedFloat64());
       // CheckValueInputIs(node, 0, from));
       // CheckUpperIs(node, to));
       break;
     }
+    case IrOpcode::kChangeInt31ToTagged: {
+      // Signed31 /\ UntaggedInt32 -> Signed31 /\ Tagged
+      // TODO(neis): Activate once ChangeRepresentation works in typer.
+      // Type* from =Type::Intersect(Type::Signed31(), Type::UntaggedInt32());
+      // Type* to = Type::Intersect(Type::Signed31(), Type::Tagged());
+      // CheckValueInputIs(node, 0, from));
+      // CheckUpperIs(node, to));
+      break;
+    }
     case IrOpcode::kChangeInt32ToTagged: {
       // Signed32 /\ UntaggedInt32 -> Signed32 /\ Tagged
       // TODO(neis): Activate once ChangeRepresentation works in typer.
       // Type* from =Type::Intersect(Type::Signed32(), Type::UntaggedInt32());
       // Type* to = Type::Intersect(Type::Signed32(), Type::Tagged());
       // CheckValueInputIs(node, 0, from));
       // CheckUpperIs(node, to));
       break;
     }
     case IrOpcode::kChangeUint32ToTagged: {
@@ skipping 520 matching lines @@
          replacement->op()->EffectOutputCount() > 0);
   DCHECK(!NodeProperties::IsFrameStateEdge(edge) ||
          replacement->opcode() == IrOpcode::kFrameState);
 }
 
 #endif  // DEBUG
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8