[turbofan] Normalize union of representation and range to a range.

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 759 matching lines @@
   // remove the number bits from the bitset.
   if (!IsEmpty(lims)) {
     size = UpdateRange(RangeType::New(lims, representation, region), result,
                        size, region);
 
     // Remove the number bits.
     bitset number_bits = BitsetType::NumberBits(bits);
     bits &= ~number_bits;
     result->Set(0, BitsetType::New(bits, region));
   }
-  return NormalizeUnion(result, size);
+  return NormalizeUnion(result, size, region);
 }
 
 
 template<class Config>
 int TypeImpl<Config>::UpdateRange(
     RangeHandle range, UnionHandle result, int size, Region* region) {
   if (size == 1) {
     result->Set(size++, range);
   } else {
     // Make space for the range.
@@ skipping 194 matching lines @@
   } else if (range2 != NULL) {
     range = NormalizeRangeAndBitset(handle(range2), &new_bitset, region);
   }
   new_bitset = SEMANTIC(new_bitset) | representation;
   TypeHandle bits = BitsetType::New(new_bitset, region);
   result->Set(size++, bits);
   if (!range->IsNone()) result->Set(size++, range);
 
   size = AddToUnion(type1, result, size, region);
   size = AddToUnion(type2, result, size, region);
-  return NormalizeUnion(result, size);
+  return NormalizeUnion(result, size, region);
 }
 
 
 // Add [type] to [result] unless [type] is bitset, range, or already subsumed.
 // Return new size of [result].
 template<class Config>
 int TypeImpl<Config>::AddToUnion(
     TypeHandle type, UnionHandle result, int size, Region* region) {
   if (type->IsBitset() || type->IsRange()) return size;
   if (type->IsUnion()) {
     for (int i = 0, n = type->AsUnion()->Length(); i < n; ++i) {
       size = AddToUnion(type->AsUnion()->Get(i), result, size, region);
     }
     return size;
   }
   for (int i = 0; i < size; ++i) {
     if (type->SemanticIs(result->Get(i)->unhandle())) return size;
   }
   result->Set(size++, type);
   return size;
 }
 
 
-template<class Config>
+template <class Config>
 typename TypeImpl<Config>::TypeHandle TypeImpl<Config>::NormalizeUnion(
-    UnionHandle unioned, int size) {
+    UnionHandle unioned, int size, Region* region) {
   DCHECK(size >= 1);
   DCHECK(unioned->Get(0)->IsBitset());
   // If the union has just one element, return it.
   if (size == 1) {
     return unioned->Get(0);
   }
   bitset bits = unioned->Get(0)->AsBitset();
   // If the union only consists of a range, we can get rid of the union.
   if (size == 2 && SEMANTIC(bits) == BitsetType::kNone) {
     bitset representation = REPRESENTATION(bits);
     if (representation == unioned->Get(1)->Representation()) {
       return unioned->Get(1);
     }
-    // TODO(jarin) If the element at 1 is range of constant, slap
-    // the representation on it and return that.
+    if (unioned->Get(1)->IsRange()) {
+      return RangeType::New(unioned->Get(1)->AsRange()->Min(),
+                            unioned->Get(1)->AsRange()->Max(), unioned->Get(0),
+                            region);
+    }
   }
   unioned->Shrink(size);
   SLOW_DCHECK(unioned->Wellformed());
   return unioned;
 }
 
 
 // -----------------------------------------------------------------------------
 // Component extraction
 
@@ skipping 310 matching lines @@
 template class TypeImpl<HeapTypeConfig>::Iterator<i::Object>;
 
 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 v8::internal