Extend some operations to range types.

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 "src/types.h"
 
 #include "src/ostreams.h"
 #include "src/types-inl.h"
 
 namespace v8 {
 namespace internal {
 
+
+// -----------------------------------------------------------------------------
+// Range-related custom order on doubles.
+// We want -0 to be less than +0.
+
+static bool dle(double x, double y) {
+  return x <= y && (!IsMinusZero(y) || x != 0 || IsMinusZero(x));

[rossberg, 2014/08/07 14:12:57]

Nit: I would order this

(x != 0 || IsMinusZero(x) || !IsMinusZero(y))

+}
+
+
+static bool deq(double x, double y) {
+  return dle(x, y) && dle(y, x);
+}
+
+
 // -----------------------------------------------------------------------------
 // Glb and lub computation.
 
 // The largest bitset subsumed by this type.
 template<class Config>
 int TypeImpl<Config>::BitsetType::Glb(TypeImpl* type) {
   DisallowHeapAllocation no_allocation;
   if (type->IsBitset()) {
     return type->AsBitset();
   } else if (type->IsUnion()) {
@@ skipping 18 matching lines @@
     for (int i = 0; i < unioned->Length(); ++i) {
       bitset |= unioned->Get(i)->BitsetLub();
     }
     return bitset;
   } else 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();
   } else if (type->IsConstant()) {
     return type->AsConstant()->Bound()->AsBitset();
+  } else if (type->IsRange()) {
+    return type->AsRange()->Bound()->AsBitset();
   } else if (type->IsContext()) {
     return type->AsContext()->Bound()->AsBitset();
   } else if (type->IsArray()) {
     return type->AsArray()->Bound()->AsBitset();
   } else if (type->IsFunction()) {
     return type->AsFunction()->Bound()->AsBitset();
   } else {
     UNREACHABLE();
     return kNone;
   }
@@ skipping 10 matching lines @@
     UnionHandle unioned = handle(type->AsUnion());
     int bitset = kNone;
     for (int i = 0; i < unioned->Length(); ++i) {
       bitset |= unioned->Get(i)->InherentBitsetLub();
     }
     return bitset;
   } else if (type->IsClass()) {
     return Lub(*type->AsClass()->Map());
   } else if (type->IsConstant()) {
     return Lub(*type->AsConstant()->Value());
+  } else if (type->IsRange()) {
+    return Lub(type->AsRange()->Min(), type->AsRange()->Max());
   } else if (type->IsContext()) {
     return kInternal & kTaggedPtr;
   } else if (type->IsArray()) {
     return kArray;
   } else if (type->IsFunction()) {
     return kFunction;
   } else {
     UNREACHABLE();
     return kNone;
   }
@@ skipping 15 matching lines @@
   DisallowHeapAllocation no_allocation;
   if (i::IsMinusZero(value)) return kMinusZero;
   if (std::isnan(value)) return kNaN;
   if (IsUint32Double(value)) return Lub(FastD2UI(value));
   if (IsInt32Double(value)) return Lub(FastD2I(value));
   return kOtherNumber;
 }
 
 
 template<class Config>
+int TypeImpl<Config>::BitsetType::Lub(double min, double max) {
+  DisallowHeapAllocation no_allocation;
+  DCHECK(dle(min, max));
+  if (deq(min, max)) return BitsetType::Lub(min);  // Singleton range.
+  int bitset = BitsetType::kNumber ^ SEMANTIC(BitsetType::kNaN);
+  if (dle(0, min) || max < 0) bitset ^= SEMANTIC(BitsetType::kMinusZero);
+  return bitset;
+  // TODO(neis): Could refine this further by doing more checks on min/max.
+}
+
+
+template<class Config>
 int TypeImpl<Config>::BitsetType::Lub(int32_t value) {
   if (value >= 0x40000000) {
     return i::SmiValuesAre31Bits() ? kOtherUnsigned31 : kUnsignedSmall;
   }
   if (value >= 0) return kUnsignedSmall;
   if (value >= -0x40000000) return kOtherSignedSmall;
   return i::SmiValuesAre31Bits() ? kOtherSigned32 : kOtherSignedSmall;
 }
 
 
@@ skipping 123 matching lines @@
         && *this->AsClass()->Map() == *that->AsClass()->Map()
         && ((Config::is_class(that) && Config::is_class(this)) ||
             BitsetType::New(this->BitsetLub())->Is(
                 BitsetType::New(that->BitsetLub())));
   }
   if (that->IsConstant()) {
     return this->IsConstant()
         && *this->AsConstant()->Value() == *that->AsConstant()->Value()
         && this->AsConstant()->Bound()->Is(that->AsConstant()->Bound());
   }
+  if (that->IsRange()) {
+    return this->IsRange()
+        && this->AsRange()->Bound()->Is(that->AsRange()->Bound())
+        && dle(that->AsRange()->Min(), this->AsRange()->Min())
+        && dle(this->AsRange()->Max(), that->AsRange()->Max());
+  }
   if (that->IsContext()) {
     return this->IsContext()
         && this->AsContext()->Outer()->Equals(that->AsContext()->Outer());
   }
   if (that->IsArray()) {
     return this->IsArray()
         && this->AsArray()->Element()->Equals(that->AsArray()->Element());
   }
   if (that->IsFunction()) {
     // We currently do not allow for any variance here, in order to keep
@@ skipping 112 matching lines @@
   }
 
   return false;
 }
 
 
 // Check if value is contained in (inhabits) type.
 template<class Config>
 bool TypeImpl<Config>::Contains(i::Object* value) {
   DisallowHeapAllocation no_allocation;
+  if (this->IsRange()) {
+    return value->IsNumber() &&
+           dle(this->AsRange()->Min(), value->Number()) &&
+           dle(value->Number(), this->AsRange()->Max()) &&
+           BitsetType::Is(BitsetType::Lub(value), this->BitsetLub());
+  }
   for (Iterator<i::Object> it = this->Constants(); !it.Done(); it.Advance()) {
     if (*it.Current() == value) return true;
   }
   return BitsetType::New(BitsetType::Lub(value))->Is(this);
 }
 
 
 template<class Config>
 bool TypeImpl<Config>::UnionType::Wellformed() {
   DCHECK(this->Length() >= 2);
@@ skipping 12 matching lines @@
 // Union and intersection
 
 template<class Config>
 typename TypeImpl<Config>::TypeHandle TypeImpl<Config>::Rebound(
     int bitset, Region* region) {
   TypeHandle bound = BitsetType::New(bitset, region);
   if (this->IsClass()) {
     return ClassType::New(this->AsClass()->Map(), bound, region);
   } else if (this->IsConstant()) {
     return ConstantType::New(this->AsConstant()->Value(), bound, region);
+  } else if (this->IsRange()) {
+    return RangeType::New(
+        this->AsRange()->Min(), this->AsRange()->Max(), bound, region);
   } else if (this->IsContext()) {
     return ContextType::New(this->AsContext()->Outer(), bound, region);
   } else if (this->IsArray()) {
     return ArrayType::New(this->AsArray()->Element(), bound, region);
   } else if (this->IsFunction()) {
     FunctionHandle function = Config::handle(this->AsFunction());
     int arity = function->Arity();
     FunctionHandle type = FunctionType::New(
         function->Result(), function->Receiver(), bound, arity, region);
     for (int i = 0; i < arity; ++i) {
@@ skipping 68 matching lines @@
   if (type->IsUnion()) {
     UnionHandle unioned = handle(type->AsUnion());
     for (int i = 0; i < unioned->Length(); ++i) {
       TypeHandle type_i = unioned->Get(i);
       DCHECK(i == 0 || !(type_i->IsBitset() || type_i->Is(unioned->Get(0))));
       if (!type_i->IsBitset()) {
         size = ExtendUnion(result, size, type_i, other, is_intersect, region);
       }
     }
   } else if (!type->IsBitset()) {
-    DCHECK(type->IsClass() || type->IsConstant() ||
-           type->IsArray() || type->IsFunction() || type->IsContext());
+    DCHECK(type->IsClass() || type->IsConstant() || type->IsRange() ||
+           type->IsContext() || type->IsArray() || type->IsFunction());
     int inherent_bound = type->InherentBitsetLub();
     int old_bound = type->BitsetLub();
     int other_bound = type->BoundBy(other->unhandle()) & inherent_bound;
     int new_bound =
         is_intersect ? (old_bound & other_bound) : (old_bound | other_bound);
     if (new_bound != BitsetType::kNone) {
       int i = type->IndexInUnion(new_bound, result, size);
       if (i == -1) {
         i = size++;
       } else if (result->Get(i)->IsBitset()) {
@@ skipping 222 matching lines @@
 typename TypeImpl<Config>::TypeHandle TypeImpl<Config>::Convert(
     typename OtherType::TypeHandle type, Region* region) {
   if (type->IsBitset()) {
     return BitsetType::New(type->AsBitset(), region);
   } else if (type->IsClass()) {
     TypeHandle bound = BitsetType::New(type->BitsetLub(), region);
     return ClassType::New(type->AsClass()->Map(), bound, region);
   } else if (type->IsConstant()) {
     TypeHandle bound = Convert<OtherType>(type->AsConstant()->Bound(), region);
     return ConstantType::New(type->AsConstant()->Value(), bound, region);
+  } else if (type->IsRange()) {
+    TypeHandle bound = Convert<OtherType>(type->AsRange()->Bound(), region);
+    return RangeType::New(
+        type->AsRange()->Min(), type->AsRange()->Max(), bound, region);
   } else if (type->IsContext()) {
     TypeHandle bound = Convert<OtherType>(type->AsContext()->Bound(), region);
     TypeHandle outer = Convert<OtherType>(type->AsContext()->Outer(), region);
     return ContextType::New(outer, bound, region);
   } else if (type->IsUnion()) {
     int length = type->AsUnion()->Length();
     UnionHandle unioned = UnionType::New(length, region);
     for (int i = 0; i < length; ++i) {
       TypeHandle t = Convert<OtherType>(type->AsUnion()->Get(i), region);
       unioned->Set(i, t);
@@ skipping 163 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