[turbofan] Initial version of number type feedback.

src/compiler/type-hints.cc

 // Copyright 2015 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/type-hints.h"
 
 namespace v8 {
 namespace internal {
 namespace compiler {
 
 std::ostream& operator<<(std::ostream& os, BinaryOperationHints::Hint hint) {
   switch (hint) {
     case BinaryOperationHints::kNone:
       return os << "None";
     case BinaryOperationHints::kSignedSmall:
       return os << "SignedSmall";
     case BinaryOperationHints::kSigned32:
       return os << "Signed32";
-    case BinaryOperationHints::kNumber:
-      return os << "Number";
+    case BinaryOperationHints::kNumberOrUndefined:
+      return os << "NumberOrUndefined";
     case BinaryOperationHints::kString:
       return os << "String";
     case BinaryOperationHints::kAny:
       return os << "Any";
   }
   UNREACHABLE();
   return os;
 }
 
 
@@ skipping 40 matching lines @@
     ToBooleanHint const hint = static_cast<ToBooleanHint>(1u << i);
     if (hints & hint) {
       if (!first) os << "|";
       first = false;
       os << hint;
     }
   }
   return os;
 }
 
+// static
+bool BinaryOperationHints::Is(Hint h1, Hint h2) {
+  if (h1 == h2) return true;
+  switch (h1) {
+    case kNone:
+      return true;
+    case kSignedSmall:
+      return h2 == kSigned32 || h2 == kNumberOrUndefined || h2 == kAny;
+    case kSigned32:
+      return h2 == kNumberOrUndefined || h2 == kAny;
+    case kNumberOrUndefined:
+      return h2 == kAny;
+    case kString:
+      return h2 == kAny;
+    case kAny:
+      return false;
+  }
+  UNREACHABLE();
+  return false;
+}
+
+// static
+BinaryOperationHints::Hint BinaryOperationHints::Combine(Hint h1, Hint h2) {
+  if (Is(h1, h2)) return h2;
+  if (Is(h2, h1)) return h1;
+  return kAny;
+}
+
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8