ryujinx/ARMeilleure/IntermediateRepresentation/IntrusiveList.cs
gdkchan e5f78fb1d4
Replace LinkedList by IntrusiveList to avoid allocations on JIT (#931)
* Replace LinkedList by IntrusiveList to avoid allocations on JIT

* Fix wrong replacements
2020-02-17 22:30:54 +01:00

179 lines
4.9 KiB
C#

using System.Diagnostics;
using System.Runtime.CompilerServices;
namespace ARMeilleure.IntermediateRepresentation
{
/// <summary>
/// Represents a efficient linked list that stores the pointer on the object directly and does not allocate.
/// </summary>
/// <typeparam name="T">Type of the list items</typeparam>
class IntrusiveList<T> where T : class, IIntrusiveListNode<T>
{
/// <summary>
/// First item of the list, or null if empty.
/// </summary>
public T First { get; private set; }
/// <summary>
/// Last item of the list, or null if empty.
/// </summary>
public T Last { get; private set; }
/// <summary>
/// Total number of items on the list.
/// </summary>
public int Count { get; private set; }
/// <summary>
/// Adds a item as the first item of the list.
/// </summary>
/// <param name="newNode">Item to be added</param>
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public void AddFirst(T newNode)
{
if (First != null)
{
AddBefore(First, newNode);
}
else
{
Debug.Assert(newNode.ListPrevious == null);
Debug.Assert(newNode.ListNext == null);
Debug.Assert(Last == null);
First = newNode;
Last = newNode;
Debug.Assert(Count == 0);
Count = 1;
}
}
/// <summary>
/// Adds a item as the last item of the list.
/// </summary>
/// <param name="newNode">Item to be added</param>
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public void AddLast(T newNode)
{
if (Last != null)
{
AddAfter(Last, newNode);
}
else
{
Debug.Assert(newNode.ListPrevious == null);
Debug.Assert(newNode.ListNext == null);
Debug.Assert(First == null);
First = newNode;
Last = newNode;
Debug.Assert(Count == 0);
Count = 1;
}
}
/// <summary>
/// Adds a item before a existing item on the list.
/// </summary>
/// <param name="node">Item on the list that will succeed the new item</param>
/// <param name="newNode">Item to be added</param>
/// <returns>New item</returns>
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public T AddBefore(T node, T newNode)
{
Debug.Assert(newNode.ListPrevious == null);
Debug.Assert(newNode.ListNext == null);
newNode.ListPrevious = node.ListPrevious;
newNode.ListNext = node;
node.ListPrevious = newNode;
if (newNode.ListPrevious != null)
{
newNode.ListPrevious.ListNext = newNode;
}
if (First == node)
{
First = newNode;
}
Count++;
return newNode;
}
/// <summary>
/// Adds a item after a existing item on the list.
/// </summary>
/// <param name="node">Item on the list that will preceed the new item</param>
/// <param name="newNode">Item to be added</param>
/// <returns>New item</returns>
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public T AddAfter(T node, T newNode)
{
Debug.Assert(newNode.ListPrevious == null);
Debug.Assert(newNode.ListNext == null);
newNode.ListPrevious = node;
newNode.ListNext = node.ListNext;
node.ListNext = newNode;
if (newNode.ListNext != null)
{
newNode.ListNext.ListPrevious = newNode;
}
if (Last == node)
{
Last = newNode;
}
Count++;
return newNode;
}
/// <summary>
/// Removes a item from the list.
/// </summary>
/// <param name="node">The item to be removed</param>
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public void Remove(T node)
{
if (node.ListPrevious != null)
{
node.ListPrevious.ListNext = node.ListNext;
}
else
{
Debug.Assert(First == node);
First = node.ListNext;
}
if (node.ListNext != null)
{
node.ListNext.ListPrevious = node.ListPrevious;
}
else
{
Debug.Assert(Last == node);
Last = node.ListPrevious;
}
node.ListPrevious = null;
node.ListNext = null;
Count--;
}
}
}