Revert #1142 - Remove unboxed objects

- accounting for removal of watch()/unwatch()

1 files changed, 183 insertions, 0 deletions

diff --git a/js/src/jit/IonBuilder.cpp b/js/src/jit/IonBuilder.cpp
index 1e12f5dbe..f00167d92 100644
--- a/js/src/jit/IonBuilder.cpp
+++ b/js/src/jit/IonBuilder.cpp
@@ -10940,6 +10940,63 @@ IonBuilder::getDefiniteSlot(TemporaryTypeSet* types, PropertyName* name, uint32_
     return slot;
 }
 
+uint32_t
+IonBuilder::getUnboxedOffset(TemporaryTypeSet* types, PropertyName* name, JSValueType* punboxedType)
+{
+    if (!types || types->unknownObject() || !types->objectOrSentinel()) {
+        trackOptimizationOutcome(TrackedOutcome::NoTypeInfo);
+        return UINT32_MAX;
+    }
+
+    uint32_t offset = UINT32_MAX;
+
+    for (size_t i = 0; i < types->getObjectCount(); i++) {
+        TypeSet::ObjectKey* key = types->getObject(i);
+        if (!key)
+            continue;
+
+        if (key->unknownProperties()) {
+            trackOptimizationOutcome(TrackedOutcome::UnknownProperties);
+            return UINT32_MAX;
+        }
+
+        if (key->isSingleton()) {
+            trackOptimizationOutcome(TrackedOutcome::Singleton);
+            return UINT32_MAX;
+        }
+
+        UnboxedLayout* layout = key->group()->maybeUnboxedLayout();
+        if (!layout) {
+            trackOptimizationOutcome(TrackedOutcome::NotUnboxed);
+            return UINT32_MAX;
+        }
+
+        const UnboxedLayout::Property* property = layout->lookup(name);
+        if (!property) {
+            trackOptimizationOutcome(TrackedOutcome::StructNoField);
+            return UINT32_MAX;
+        }
+
+        if (layout->nativeGroup()) {
+            trackOptimizationOutcome(TrackedOutcome::UnboxedConvertedToNative);
+            return UINT32_MAX;
+        }
+
+        if (offset == UINT32_MAX) {
+            offset = property->offset;
+            *punboxedType = property->type;
+        } else if (offset != property->offset) {
+            trackOptimizationOutcome(TrackedOutcome::InconsistentFieldOffset);
+            return UINT32_MAX;
+        } else if (*punboxedType != property->type) {
+            trackOptimizationOutcome(TrackedOutcome::InconsistentFieldType);
+            return UINT32_MAX;
+        }
+    }
+
+    return offset;
+}
+
 bool
 IonBuilder::jsop_runonce()
 {
@@ -11906,6 +11963,72 @@ IonBuilder::getPropTryModuleNamespace(bool* emitted, MDefinition* obj, PropertyN
     return true;
 }
 
+MInstruction*
+IonBuilder::loadUnboxedProperty(MDefinition* obj, size_t offset, JSValueType unboxedType,
+                                BarrierKind barrier, TemporaryTypeSet* types)
+{
+    // loadUnboxedValue is designed to load any value as if it were contained in
+    // an array. Thus a property offset is converted to an index, when the
+    // object is reinterpreted as an array of properties of the same size.
+    size_t index = offset / UnboxedTypeSize(unboxedType);
+    MInstruction* indexConstant = MConstant::New(alloc(), Int32Value(index));
+    current->add(indexConstant);
+
+    return loadUnboxedValue(obj, UnboxedPlainObject::offsetOfData(),
+                            indexConstant, unboxedType, barrier, types);
+}
+
+MInstruction*
+IonBuilder::loadUnboxedValue(MDefinition* elements, size_t elementsOffset,
+                             MDefinition* index, JSValueType unboxedType,
+                             BarrierKind barrier, TemporaryTypeSet* types)
+{
+    MInstruction* load;
+    switch (unboxedType) {
+      case JSVAL_TYPE_BOOLEAN:
+        load = MLoadUnboxedScalar::New(alloc(), elements, index, Scalar::Uint8,
+                                       DoesNotRequireMemoryBarrier, elementsOffset);
+        load->setResultType(MIRType::Boolean);
+        break;
+
+      case JSVAL_TYPE_INT32:
+        load = MLoadUnboxedScalar::New(alloc(), elements, index, Scalar::Int32,
+                                       DoesNotRequireMemoryBarrier, elementsOffset);
+        load->setResultType(MIRType::Int32);
+        break;
+
+      case JSVAL_TYPE_DOUBLE:
+        load = MLoadUnboxedScalar::New(alloc(), elements, index, Scalar::Float64,
+                                       DoesNotRequireMemoryBarrier, elementsOffset,
+                                       /* canonicalizeDoubles = */ false);
+        load->setResultType(MIRType::Double);
+        break;
+
+      case JSVAL_TYPE_STRING:
+        load = MLoadUnboxedString::New(alloc(), elements, index, elementsOffset);
+        break;
+
+      case JSVAL_TYPE_OBJECT: {
+        MLoadUnboxedObjectOrNull::NullBehavior nullBehavior;
+        if (types->hasType(TypeSet::NullType()))
+            nullBehavior = MLoadUnboxedObjectOrNull::HandleNull;
+        else if (barrier != BarrierKind::NoBarrier)
+            nullBehavior = MLoadUnboxedObjectOrNull::BailOnNull;
+        else
+            nullBehavior = MLoadUnboxedObjectOrNull::NullNotPossible;
+        load = MLoadUnboxedObjectOrNull::New(alloc(), elements, index, nullBehavior,
+                                             elementsOffset);
+        break;
+      }
+
+      default:
+        MOZ_CRASH();
+    }
+
+    current->add(load);
+    return load;
+}
+
 MDefinition*
 IonBuilder::addShapeGuardsForGetterSetter(MDefinition* obj, JSObject* holder, Shape* holderShape,
                 const BaselineInspector::ReceiverVector& receivers,
@@ -12729,6 +12852,66 @@ IonBuilder::setPropTryDefiniteSlot(bool* emitted, MDefinition* obj,
     return true;
 }
 
+MInstruction*
+IonBuilder::storeUnboxedProperty(MDefinition* obj, size_t offset, JSValueType unboxedType,
+                                 MDefinition* value)
+{
+    size_t scaledOffsetConstant = offset / UnboxedTypeSize(unboxedType);
+    MInstruction* scaledOffset = MConstant::New(alloc(), Int32Value(scaledOffsetConstant));
+    current->add(scaledOffset);
+
+    return storeUnboxedValue(obj, obj, UnboxedPlainObject::offsetOfData(),
+                             scaledOffset, unboxedType, value);
+}
+
+MInstruction*
+IonBuilder::storeUnboxedValue(MDefinition* obj, MDefinition* elements, int32_t elementsOffset,
+                              MDefinition* scaledOffset, JSValueType unboxedType,
+                              MDefinition* value, bool preBarrier /* = true */)
+{
+    MInstruction* store;
+    switch (unboxedType) {
+      case JSVAL_TYPE_BOOLEAN:
+        store = MStoreUnboxedScalar::New(alloc(), elements, scaledOffset, value, Scalar::Uint8,
+                                         MStoreUnboxedScalar::DontTruncateInput,
+                                         DoesNotRequireMemoryBarrier, elementsOffset);
+        break;
+
+      case JSVAL_TYPE_INT32:
+        store = MStoreUnboxedScalar::New(alloc(), elements, scaledOffset, value, Scalar::Int32,
+                                         MStoreUnboxedScalar::DontTruncateInput,
+                                         DoesNotRequireMemoryBarrier, elementsOffset);
+        break;
+
+      case JSVAL_TYPE_DOUBLE:
+        store = MStoreUnboxedScalar::New(alloc(), elements, scaledOffset, value, Scalar::Float64,
+                                         MStoreUnboxedScalar::DontTruncateInput,
+                                         DoesNotRequireMemoryBarrier, elementsOffset);
+        break;
+
+      case JSVAL_TYPE_STRING:
+        store = MStoreUnboxedString::New(alloc(), elements, scaledOffset, value,
+                                         elementsOffset, preBarrier);
+        break;
+
+      case JSVAL_TYPE_OBJECT:
+        MOZ_ASSERT(value->type() == MIRType::Object ||
+                   value->type() == MIRType::Null ||
+                   value->type() == MIRType::Value);
+        MOZ_ASSERT(!value->mightBeType(MIRType::Undefined),
+                   "MToObjectOrNull slow path is invalid for unboxed objects");
+        store = MStoreUnboxedObjectOrNull::New(alloc(), elements, scaledOffset, value, obj,
+                                               elementsOffset, preBarrier);
+        break;
+
+      default:
+        MOZ_CRASH();
+    }
+
+    current->add(store);
+    return store;
+}
+
 bool
 IonBuilder::setPropTryInlineAccess(bool* emitted, MDefinition* obj,
                                    PropertyName* name, MDefinition* value,