public static SymbolicSlot Merge(SymbolicSlot first, SymbolicSlot second)
{
if (first == second)
{
return(first);
}
var result = new SymbolicSlot();
Merge(first, second, result);
return(result);
}
// store by address
public void Store(SymbolicSlot value)
{
if (IsConstAfterSimplification() || value.IsConstAfterSimplification())
{
return;
}
// store like a field because we should create a snapshot in the moment
// and avoid cycled references in the "values" field
MaterializeFields();
value.MaterializeFields();
if (IsConstAfterSimplification() || value.IsConstAfterSimplification())
{
return;
}
var mergedEntity = SymbolicReference.Merge(entities, value.entities);
entities = new[] { mergedEntity };
value.entities = new[] { mergedEntity };
}
public void StoreField(string name, SymbolicSlot value)
{
if (IsConstAfterSimplification() || value.IsConstAfterSimplification())
{
return;
}
MaterializeFields();
value.MaterializeFields();
if (IsConstAfterSimplification() || value.IsConstAfterSimplification())
{
return;
}
var targetEntity = SymbolicReference.Merge(value.entities);
for (int i = 0; i < entities.Length; i++)
{
var entity = entities[i];
entity.StoreField(name, targetEntity);
}
}
private static List <SymbolicReference> MaterializeFields(SymbolicSlot value)
{
var newEntities = new List <SymbolicReference>();
var queue = new Queue <(SymbolicSlot, string[][])>();
queue.Enqueue((value, new string[0][]));
// var context = new VisitingContext<SymbolicSlot>();
while (queue.Count > 0)
{
var(slot, topFields) = queue.Dequeue();
// if (!context.Visit(slot))
// continue;
if (slot.values != null)
{
Debug.Assert(slot.entities == null);
string[][] allFields;
if (slot.fields != null)
{
allFields = new string[topFields.Length + 1][];
Array.Copy(topFields, allFields, topFields.Length);
allFields[allFields.Length - 1] = slot.fields;
}
else
{
allFields = topFields;
}
for (int i = 0; i < slot.values.Length; i++)
{
queue.Enqueue((slot.values[i], allFields));
}
}
else if (slot.entities != null)
{
Debug.Assert(slot.values == null);
for (int i = 0; i < slot.entities.Length; i++)
{
var entity = slot.entities[i];
if (slot.fields != null)
{
for (int f = 0; f < slot.fields.Length; f++)
{
var field = slot.fields[f];
entity = entity.LoadField(field);
}
}
for (int j = topFields.Length - 1; j >= 0; j--)
{
var slotFields = topFields[j];
for (int f = 0; f < slotFields.Length; f++)
{
var field = slotFields[f];
entity = entity.LoadField(field);
}
}
newEntities.Add(entity);
}
}
else
{
Debug.Fail("SSlot must contain either values or entities");
}
}
return(newEntities);
}
private static void Merge(SymbolicSlot first, SymbolicSlot second, SymbolicSlot result)
{
if (first.fields == null && second.fields == null)
{
if (first.entities != null && second.entities != null)
{
Debug.Assert(first.entities.Length > 0 && second.entities.Length > 0);
Debug.Assert(first.values == null && second.values == null);
var newEntities = new SymbolicReference[first.entities.Length + second.entities.Length];
Array.Copy(first.entities, newEntities, first.entities.Length);
Array.Copy(second.entities, 0, newEntities, first.entities.Length, second.entities.Length);
result.Reset(newEntities, null, null);
return;
}
if (first.entities != null)
{
Debug.Assert(first.entities.Length > 0 && second.entities == null);
Debug.Assert(first.values == null && second.values != null);
var newValues = new SymbolicSlot[second.values.Length + 1];
Array.Copy(second.values, newValues, second.values.Length);
newValues[newValues.Length - 1] = new SymbolicSlot(first.entities, null, null);
result.Reset(null, newValues, null);
return;
}
if (second.entities != null)
{
Debug.Assert(first.entities == null && second.entities.Length > 0);
Debug.Assert(first.values != null && second.values == null);
var newValues = new SymbolicSlot[first.values.Length + 1];
Array.Copy(first.values, newValues, first.values.Length);
newValues[newValues.Length - 1] = new SymbolicSlot(second.entities, null, null);
result.Reset(null, newValues, null);
return;
}
{
Debug.Assert(first.entities == null && second.entities == null);
Debug.Assert(first.values != null && second.values != null);
Debug.Assert(first.values.Length > 0 && second.values.Length > 0);
var newValues = new SymbolicSlot[first.values.Length + second.values.Length];
Array.Copy(first.values, newValues, first.values.Length);
Array.Copy(second.values, 0, newValues, first.values.Length, second.values.Length);
result.Reset(null, newValues, null);
return;
}
}
if (first.fields == null && first.values != null)
{
Debug.Assert(first.entities == null);
Debug.Assert(first.values.Length > 0);
var newValues = new SymbolicSlot[first.values.Length + 1];
Array.Copy(first.values, newValues, first.values.Length);
newValues[newValues.Length - 1] = second;
result.Reset(null, newValues, null);
return;
}
if (second.fields == null && second.values != null)
{
Debug.Assert(second.entities == null);
Debug.Assert(second.values.Length > 0);
var newValues = new SymbolicSlot[second.values.Length + 1];
Array.Copy(second.values, newValues, second.values.Length);
newValues[newValues.Length - 1] = first;
result.Reset(null, newValues, null);
return;
}
result.Reset(null, new [] { first, second }, null);
}