[turbofan] Checking monotonicity of representation inference outputs and inputs.

src/compiler/representation-change.h

 // 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.
 
 #ifndef V8_COMPILER_REPRESENTATION_CHANGE_H_
 #define V8_COMPILER_REPRESENTATION_CHANGE_H_
 
 #include "src/compiler/js-graph.h"
 #include "src/compiler/simplified-operator.h"
 
@@ skipping 28 matching lines @@
     return LessGeneral(kind_, TruncationKind::kFloat64) ||
            LessGeneral(kind_, TruncationKind::kWord64);
   }
 
   // Operators.
   bool operator==(Truncation other) const { return kind() == other.kind(); }
   bool operator!=(Truncation other) const { return !(*this == other); }
 
   // Debug utilities.
   const char* description() const;
+  bool IsLessGeneralThan(Truncation other) {
+    return LessGeneral(kind(), other.kind());
+  }
 
  private:
   enum class TruncationKind : uint8_t {
     kNone,
     kBool,
     kWord32,
     kWord64,
     kFloat32,
     kFloat64,
     kAny
@@ skipping 68 matching lines @@
   Factory* factory() const { return isolate()->factory(); }
   SimplifiedOperatorBuilder* simplified() { return jsgraph()->simplified(); }
   MachineOperatorBuilder* machine() { return jsgraph()->machine(); }
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_REPRESENTATION_CHANGE_H_