Construct Range rather than Constant when typing integers.

src/types.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 <iomanip>
 
 #include "src/types.h"
 
 #include "src/ostreams.h"
 #include "src/types-inl.h"
@@ skipping 912 matching lines @@
   }
   if (lhs->SimplyEquals(rhs->unhandle())) {
     return AddToUnion(lhs, result, size, region);
   }
   return size;
 }
 
 
 // Make sure that we produce a well-formed range and bitset:
 // If the range is non-empty, the number bits in the bitset should be
-// clear. Moreover, if we have a canonical range (such as Signed32(),
+// clear. Moreover, if we have a canonical range (such as Signed32),
 // we want to produce a bitset rather than a range.
 template <class Config>
 typename TypeImpl<Config>::TypeHandle TypeImpl<Config>::NormalizeRangeAndBitset(
     RangeHandle range, bitset* bits, Region* region) {
   // Fast path: If the bitset does not mention numbers, we can just keep the
   // range.
   bitset number_bits = BitsetType::NumberBits(*bits);
   if (number_bits == 0) {
     return range;
   }
 
-  // If the range is contained within the bitset, return an empty range
-  // (but make sure we take the representation).
+  // If the range is semantically contained within the bitset, return None and
+  // leave the bitset untouched.
   bitset range_lub = SEMANTIC(range->BitsetLub());
   if (BitsetType::Is(BitsetType::NumberBits(range_lub), *bits)) {
     return None(region);
   }
 
   // Slow path: reconcile the bitset range and the range.
   double bitset_min = BitsetType::Min(number_bits);
   double bitset_max = BitsetType::Max(number_bits);
 
   double range_min = range->Min();
@@ skipping 29 matching lines @@
   // Fast case: top or bottom types.
   if (type1->IsAny() || type2->IsNone()) return type1;
   if (type2->IsAny() || type1->IsNone()) return type2;
 
   // Semi-fast case.
   if (type1->Is(type2)) return type2;
   if (type2->Is(type1)) return type1;
 
   // Figure out the representation of the result.
   // The rest of the method should not change this representation and
-  // it should make any decisions based on representations (i.e.,
+  // it should not make any decisions based on representations (i.e.,
   // it should only use the semantic part of types).
   const bitset representation =
       type1->Representation() | type2->Representation();
 
   // Slow case: create union.
   int size1 = type1->IsUnion() ? type1->AsUnion()->Length() : 1;
   int size2 = type2->IsUnion() ? type2->AsUnion()->Length() : 1;
   if (!AddIsSafe(size1, size2)) return Any(region);
   int size = size1 + size2;
   if (!AddIsSafe(size, 2)) return Any(region);
@@ skipping 393 matching lines @@
 
 template TypeImpl<ZoneTypeConfig>::TypeHandle
   TypeImpl<ZoneTypeConfig>::Convert<HeapType>(
     TypeImpl<HeapTypeConfig>::TypeHandle, TypeImpl<ZoneTypeConfig>::Region*);
 template TypeImpl<HeapTypeConfig>::TypeHandle
   TypeImpl<HeapTypeConfig>::Convert<Type>(
     TypeImpl<ZoneTypeConfig>::TypeHandle, TypeImpl<HeapTypeConfig>::Region*);
 
 }  // namespace internal
 }  // namespace v8