Intersection of certain constants with bitsets was wrongly non-empty.

R=jarin
BUG=

Review URL: https://codereview.chromium.org/1343933002

Cr-Commit-Position: refs/heads/master@{#30790}

src/compiler/typer.cc

@@ -53,6 +53,7 @@ Typer::Typer(Isolate* isolate, Graph* graph, Type::FunctionType* function_type)
   Type* truncating_to_zero =
       Type::Union(Type::Union(infinity, minus_infinity, zone),
                   Type::MinusZeroOrNaN(), zone);
+  DCHECK(!truncating_to_zero->Maybe(Type::Integral32()));
 
   singleton_false_ = Type::Constant(factory->false_value(), zone);
   singleton_true_ = Type::Constant(factory->true_value(), zone);

src/types.cc

@@ -152,7 +152,7 @@ TypeImpl<Config>::BitsetType::Glb(TypeImpl* type) {
 }
 
 
-// The smallest bitset subsuming this type.
+// The smallest bitset subsuming this type, possibly not a proper one.
 template<class Config>
 typename TypeImpl<Config>::bitset
 TypeImpl<Config>::BitsetType::Lub(TypeImpl* type) {
@@ -168,13 +168,9 @@ TypeImpl<Config>::BitsetType::Lub(TypeImpl* type) {
     }
     return bitset;
   }
-  if (type->IsClass()) {
-    // Little hack to avoid the need for a region for handlification here...
-    return Config::is_class(type) ? Lub(*Config::as_class(type)) :
-        type->AsClass()->Bound(NULL)->AsBitset();
-  }
-  if (type->IsConstant()) return type->AsConstant()->Bound()->AsBitset();
-  if (type->IsRange()) return type->AsRange()->Bound();
+  if (type->IsClass()) return type->AsClass()->Lub();
+  if (type->IsConstant()) return type->AsConstant()->Lub();
+  if (type->IsRange()) return type->AsRange()->Lub();
   if (type->IsContext()) return kInternal & kTaggedPointer;
   if (type->IsArray()) return kOtherObject;
   if (type->IsFunction()) return kOtherObject;  // TODO(rossberg): kFunction
@@ -341,22 +337,21 @@ TypeImpl<Config>::BitsetType::Lub(double value) {
   if (i::IsMinusZero(value)) return kMinusZero;
   if (std::isnan(value)) return kNaN;
   if (IsUint32Double(value) || IsInt32Double(value)) return Lub(value, value);
-  return kPlainNumber;
+  return kOtherNumber;
 }
 
 
-// Minimum values of regular numeric bitsets.
+// Minimum values of plain numeric bitsets.
 template <class Config>
 const typename TypeImpl<Config>::BitsetType::Boundary
-    TypeImpl<Config>::BitsetType::BoundariesArray[] = {
-  {kPlainNumber, -V8_INFINITY},
-  {kNegative32, kMinInt},
-  {kNegative31, -0x40000000},
-  {kUnsigned30, 0},
-  {kUnsigned31, 0x40000000},
-  {kUnsigned32, 0x80000000},
-  {kPlainNumber, static_cast<double>(kMaxUInt32) + 1}
-};
+TypeImpl<Config>::BitsetType::BoundariesArray[] = {
+        {kOtherNumber, kPlainNumber, -V8_INFINITY},
+        {kOtherSigned32, kNegative32, kMinInt},
+        {kNegative31, kNegative31, -0x40000000},
+        {kUnsigned30, kUnsigned30, 0},
+        {kOtherUnsigned31, kUnsigned31, 0x40000000},
+        {kOtherUnsigned32, kUnsigned32, 0x80000000},
+        {kOtherNumber, kPlainNumber, static_cast<double>(kMaxUInt32) + 1}};
 
 
 template <class Config>
@@ -374,6 +369,21 @@ size_t TypeImpl<Config>::BitsetType::BoundariesSize() {
 }
 
 
+template <class Config>
+typename TypeImpl<Config>::bitset TypeImpl<Config>::BitsetType::ExpandInternals(
+    typename TypeImpl<Config>::bitset bits) {
+  DisallowHeapAllocation no_allocation;
+  if (!(bits & SEMANTIC(kPlainNumber))) return bits;  // Shortcut.
+  const Boundary* boundaries = Boundaries();
+  for (size_t i = 0; i < BoundariesSize(); ++i) {
+    DCHECK(BitsetType::Is(boundaries[i].internal, boundaries[i].external));
+    if (bits & SEMANTIC(boundaries[i].internal))
+      bits |= SEMANTIC(boundaries[i].external);
+  }
+  return bits;
+}
+
+
 template<class Config>
 typename TypeImpl<Config>::bitset
 TypeImpl<Config>::BitsetType::Lub(double min, double max) {
@@ -381,18 +391,13 @@ TypeImpl<Config>::BitsetType::Lub(double min, double max) {
   int lub = kNone;
   const Boundary* mins = Boundaries();
 
-  // Make sure the min-max range touches 0, so we are guaranteed no holes
-  // in unions of valid bitsets.
-  if (max < -1) max = -1;
-  if (min > 0) min = 0;
-
   for (size_t i = 1; i < BoundariesSize(); ++i) {
     if (min < mins[i].min) {
-      lub |= mins[i-1].bits;
+      lub |= mins[i-1].internal;
       if (max < mins[i].min) return lub;
     }
   }
-  return lub |= mins[BoundariesSize() - 1].bits;
+  return lub | mins[BoundariesSize() - 1].internal;
 }
 
 
@@ -403,16 +408,6 @@ typename TypeImpl<Config>::bitset TypeImpl<Config>::BitsetType::NumberBits(
 }
 
 
-template <class Config>
-void TypeImpl<Config>::BitsetType::CheckNumberBits(bitset bits) {
-  // Check that the bitset does not contain any holes in number ranges.
-  bitset number_bits = NumberBits(bits);
-  if (number_bits != 0) {
-    bitset lub = SEMANTIC(Lub(Min(number_bits), Max(number_bits)));
-    CHECK(lub == number_bits);
-  }
-}
-
 template <class Config>
 typename TypeImpl<Config>::bitset TypeImpl<Config>::BitsetType::Glb(
     double min, double max) {
@@ -426,13 +421,11 @@ typename TypeImpl<Config>::bitset TypeImpl<Config>::BitsetType::Glb(
   for (size_t i = 1; i + 1 < BoundariesSize(); ++i) {
     if (min <= mins[i].min) {
       if (max + 1 < mins[i + 1].min) break;
-      glb |= mins[i].bits;
+      glb |= mins[i].external;
     }
   }
   // OtherNumber also contains float numbers, so it can never be
-  // in the greatest lower bound. (There is also the small trouble
-  // of kOtherNumber having a range hole, which we can conveniently
-  // ignore here.)
+  // in the greatest lower bound.
   return glb & ~(SEMANTIC(kOtherNumber));
 }
 
@@ -444,7 +437,7 @@ double TypeImpl<Config>::BitsetType::Min(bitset bits) {
   const Boundary* mins = Boundaries();
   bool mz = SEMANTIC(bits & kMinusZero);
   for (size_t i = 0; i < BoundariesSize(); ++i) {
-    if (Is(SEMANTIC(mins[i].bits), bits)) {
+    if (Is(SEMANTIC(mins[i].internal), bits)) {
       return mz ? std::min(0.0, mins[i].min) : mins[i].min;
     }
   }
@@ -459,11 +452,11 @@ double TypeImpl<Config>::BitsetType::Max(bitset bits) {
   DCHECK(Is(SEMANTIC(bits), kNumber));
   const Boundary* mins = Boundaries();
   bool mz = SEMANTIC(bits & kMinusZero);
-  if (BitsetType::Is(SEMANTIC(mins[BoundariesSize() - 1].bits), bits)) {
+  if (BitsetType::Is(SEMANTIC(mins[BoundariesSize() - 1].internal), bits)) {
     return +V8_INFINITY;
   }
   for (size_t i = BoundariesSize() - 1; i-- > 0;) {
-    if (Is(SEMANTIC(mins[i].bits), bits)) {
+    if (Is(SEMANTIC(mins[i].internal), bits)) {
       return mz ?
           std::max(0.0, mins[i+1].min - 1) : mins[i+1].min - 1;
     }
@@ -944,7 +937,7 @@ typename TypeImpl<Config>::TypeHandle TypeImpl<Config>::NormalizeRangeAndBitset(
   // 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)) {
+  if (BitsetType::Is(range_lub, *bits)) {
     return None(region);
   }
 
@@ -956,6 +949,8 @@ typename TypeImpl<Config>::TypeHandle TypeImpl<Config>::NormalizeRangeAndBitset(
   double range_max = range->Max();
 
   // Remove the number bits from the bitset, they would just confuse us now.
+  // NOTE: bits contains OtherNumber iff bits contains PlainNumber, in which
+  // case we already returned after the subtype check above.
   *bits &= ~number_bits;
 
   if (range_min <= bitset_min && range_max >= bitset_max) {

src/types.h

@@ -257,6 +257,11 @@ namespace internal {
  *     -2^31   -2^30     0      2^30    2^31    2^32
  *
  * E.g., OtherUnsigned32 (OU32) covers all integers from 2^31 to 2^32-1.
+ *
+ * Some of the atomic numerical bitsets are internal only (see
+ * INTERNAL_BITSET_TYPE_LIST).  To a types user, they should only occur in
+ * union with certain other bitsets.  For instance, OtherNumber should only
+ * occur as part of PlainNumber.
  */
 
 #define PROPER_BITSET_TYPE_LIST(V) \
@@ -436,10 +441,12 @@ class TypeImpl : public Config::Base {
   static TypeHandle Intersect(TypeHandle type1, TypeHandle type2, Region* reg);
 
   static TypeHandle Of(double value, Region* region) {
-    return Config::from_bitset(BitsetType::Lub(value), region);
+    return Config::from_bitset(BitsetType::ExpandInternals(
+        BitsetType::Lub(value)), region);
   }
   static TypeHandle Of(i::Object* value, Region* region) {
-    return Config::from_bitset(BitsetType::Lub(value), region);
+    return Config::from_bitset(BitsetType::ExpandInternals(
+        BitsetType::Lub(value)), region);
   }
   static TypeHandle Of(i::Handle<i::Object> value, Region* region) {
     return Of(*value, region);
@@ -657,11 +664,9 @@ class TypeImpl<Config>::BitsetType : public TypeImpl<Config> {
   bitset Bitset() { return Config::as_bitset(this); }
 
   static TypeImpl* New(bitset bits) {
-    if (FLAG_enable_slow_asserts) CheckNumberBits(bits);
     return Config::from_bitset(bits);
   }
   static TypeHandle New(bitset bits, Region* region) {
-    if (FLAG_enable_slow_asserts) CheckNumberBits(bits);
     return Config::from_bitset(bits, region);
   }
 
@@ -687,6 +692,7 @@ class TypeImpl<Config>::BitsetType : public TypeImpl<Config> {
   static bitset Lub(i::Object* value);
   static bitset Lub(double value);
   static bitset Lub(double min, double max);
+  static bitset ExpandInternals(bitset bits);
 
   static const char* Name(bitset);
   static void Print(std::ostream& os, bitset);  // NOLINT
@@ -698,14 +704,13 @@ class TypeImpl<Config>::BitsetType : public TypeImpl<Config> {
 
  private:
   struct Boundary {
-    bitset bits;
+    bitset internal;
+    bitset external;
     double min;
   };
   static const Boundary BoundariesArray[];
   static inline const Boundary* Boundaries();
   static inline size_t BoundariesSize();
-
-  static void CheckNumberBits(bitset bits);
 };
 
 
@@ -790,11 +795,6 @@ class TypeImpl<Config>::UnionType : public StructuralType {
 template<class Config>
 class TypeImpl<Config>::ClassType : public StructuralType {
  public:
-  TypeHandle Bound(Region* region) {
-    return Config::is_class(this) ?
-        BitsetType::New(BitsetType::Lub(*Config::as_class(this)), region) :
-        this->Get(0);
-  }
   i::Handle<i::Map> Map() {
     return Config::is_class(this) ? Config::as_class(this) :
         this->template GetValue<i::Map>(1);
@@ -816,6 +816,14 @@ class TypeImpl<Config>::ClassType : public StructuralType {
     DCHECK(type->IsClass());
     return static_cast<ClassType*>(type);
   }
+
+ private:
+  template<class> friend class TypeImpl;
+  bitset Lub() {
+    return Config::is_class(this) ?
+        BitsetType::Lub(*Config::as_class(this)) :
+        this->Get(0)->AsBitset();
+  }
 };
 
 
@@ -825,7 +833,6 @@ class TypeImpl<Config>::ClassType : public StructuralType {
 template<class Config>
 class TypeImpl<Config>::ConstantType : public StructuralType {
  public:
-  TypeHandle Bound() { return this->Get(0); }
   i::Handle<i::Object> Value() { return this->template GetValue<i::Object>(1); }
 
   static ConstantHandle New(i::Handle<i::Object> value, Region* region) {
@@ -840,6 +847,10 @@ class TypeImpl<Config>::ConstantType : public StructuralType {
     DCHECK(type->IsConstant());
     return static_cast<ConstantType*>(type);
   }
+
+ private:
+  template<class> friend class TypeImpl;
+  bitset Lub() { return this->Get(0)->AsBitset(); }
 };
 // TODO(neis): Also cache value if numerical.
 // TODO(neis): Allow restricting the representation.
@@ -851,7 +862,6 @@ class TypeImpl<Config>::ConstantType : public StructuralType {
 template <class Config>
 class TypeImpl<Config>::RangeType : public TypeImpl<Config> {
  public:
-  bitset Bound() { return Config::range_get_bitset(Config::as_range(this)); }
   double Min() { return Config::range_get_double(Config::as_range(this), 0); }
   double Max() { return Config::range_get_double(Config::as_range(this), 1); }
 
@@ -881,8 +891,13 @@ class TypeImpl<Config>::RangeType : public TypeImpl<Config> {
     DCHECK(type->IsRange());
     return static_cast<RangeType*>(type);
   }
+
+ private:
+  template<class> friend class TypeImpl;
+  bitset Lub() {
+    return Config::range_get_bitset(Config::as_range(this));
+  }
 };
-// TODO(neis): Also cache min and max values.
 
 
 // -----------------------------------------------------------------------------