Array based RangeList that caches Address/EndAddress (#2642)

* Array based RangeList that caches Address/EndAddress

In isolation, this was more than 2x faster than the RangeList that checks using the interface. In practice I'm seeing much better results than I expected. The array is used because checking it is slightly faster than using a list, which loses time to struct copies, but I still want that data locality.

A method has been added to the list to update the cached end address, as some users of the RangeList currently modify it dynamically.

Greatly improves performance in Super Mario Odyssey, Xenoblade and any other GPU limited games.

* Address Feedback

4 files changed, 149 insertions, 42 deletions

diff --git a/Ryujinx.Graphics.Gpu/Memory/BufferModifiedRangeList.cs b/Ryujinx.Graphics.Gpu/Memory/BufferModifiedRangeList.cs
index 9e5c5e84..63227431 100644
--- a/Ryujinx.Graphics.Gpu/Memory/BufferModifiedRangeList.cs
+++ b/Ryujinx.Graphics.Gpu/Memory/BufferModifiedRangeList.cs
@@ -365,7 +365,7 @@ namespace Ryujinx.Graphics.Gpu.Memory
         {
             lock (_lock)
             {
-                Items.Clear();
+                Count = 0;
             }
         }
     }
diff --git a/Ryujinx.Memory/Range/RangeList.cs b/Ryujinx.Memory/Range/RangeList.cs
index fd260656..d82a05c5 100644
--- a/Ryujinx.Memory/Range/RangeList.cs
+++ b/Ryujinx.Memory/Range/RangeList.cs
@@ -1,6 +1,7 @@
 using System;
 using System.Collections;
 using System.Collections.Generic;
+using System.Runtime.CompilerServices;
 
 namespace Ryujinx.Memory.Range
 {
@@ -10,18 +11,40 @@ namespace Ryujinx.Memory.Range
     /// <typeparam name="T">Type of the range.</typeparam>
     public class RangeList<T> : IEnumerable<T> where T : IRange
     {
-        private const int ArrayGrowthSize = 32;
+        private readonly struct RangeItem<TValue> where TValue : IRange
+        {
+            public readonly ulong Address;
+            public readonly ulong EndAddress;
+
+            public readonly TValue Value;
+
+            public RangeItem(TValue value)
+            {
+                Value = value;
+
+                Address = value.Address;
+                EndAddress = value.Address + value.Size;
+            }
+
+            [MethodImpl(MethodImplOptions.AggressiveInlining)]
+            public bool OverlapsWith(ulong address, ulong endAddress)
+            {
+                return Address < endAddress && address < EndAddress;
+            }
+        }
 
-        protected readonly List<T> Items;
+        private const int ArrayGrowthSize = 32;
+        private const int BackingGrowthSize = 1024;
 
-        public int Count => Items.Count;
+        private RangeItem<T>[] _items;
+        public int Count { get; protected set; }
 
         /// <summary>
         /// Creates a new range list.
         /// </summary>
         public RangeList()
         {
-            Items = new List<T>();
+            _items = new RangeItem<T>[BackingGrowthSize];
         }
 
         /// <summary>
@@ -37,7 +60,40 @@ namespace Ryujinx.Memory.Range
                 index = ~index;
             }
 
-            Items.Insert(index, item);
+            Insert(index, new RangeItem<T>(item));
+        }
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        private void Insert(int index, RangeItem<T> item)
+        {
+            if (Count + 1 > _items.Length)
+            {
+                Array.Resize(ref _items, _items.Length + ArrayGrowthSize);
+            }
+
+            if (index >= Count)
+            {
+                if (index == Count)
+                {
+                    _items[Count++] = item;
+                }
+            }
+            else
+            {
+                Array.Copy(_items, index, _items, index + 1, Count - index);
+
+                _items[index] = item;
+                Count++;
+            }
+        }
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        private void RemoveAt(int index)
+        {
+            if (index < --Count)
+            {
+                Array.Copy(_items, index + 1, _items, index, Count - index);
+            }
         }
 
         /// <summary>
@@ -51,21 +107,21 @@ namespace Ryujinx.Memory.Range
 
             if (index >= 0)
             {
-                while (index > 0 && Items[index - 1].Address == item.Address)
+                while (index > 0 && _items[index - 1].Address == item.Address)
                 {
                     index--;
                 }
 
-                while (index < Items.Count)
+                while (index < Count)
                 {
-                    if (Items[index].Equals(item))
+                    if (_items[index].Value.Equals(item))
                     {
-                        Items.RemoveAt(index);
+                        RemoveAt(index);
 
                         return true;
                     }
 
-                    if (Items[index].Address > item.Address)
+                    if (_items[index].Address > item.Address)
                     {
                         break;
                     }
@@ -78,6 +134,40 @@ namespace Ryujinx.Memory.Range
         }
 
         /// <summary>
+        /// Updates an item's end address.
+        /// </summary>
+        /// <param name="item">The item to be updated</param>
+        public void UpdateEndAddress(T item)
+        {
+            int index = BinarySearch(item.Address);
+
+            if (index >= 0)
+            {
+                while (index > 0 && _items[index - 1].Address == item.Address)
+                {
+                    index--;
+                }
+
+                while (index < Count)
+                {
+                    if (_items[index].Value.Equals(item))
+                    {
+                        _items[index] = new RangeItem<T>(item);
+
+                        return;
+                    }
+
+                    if (_items[index].Address > item.Address)
+                    {
+                        break;
+                    }
+
+                    index++;
+                }
+            }
+        }
+
+        /// <summary>
         /// Gets the first item on the list overlapping in memory with the specified item.
         /// </summary>
         /// <remarks>
@@ -103,14 +193,14 @@ namespace Ryujinx.Memory.Range
         /// <returns>The overlapping item, or the default value for the type if none found</returns>
         public T FindFirstOverlap(ulong address, ulong size)
         {
-            int index = BinarySearch(address, size);
+            int index = BinarySearch(address, address + size);
 
             if (index < 0)
             {
                 return default(T);
             }
 
-            return Items[index];
+            return _items[index].Value;
         }
 
         /// <summary>
@@ -137,21 +227,23 @@ namespace Ryujinx.Memory.Range
 
             ulong endAddress = address + size;
 
-            foreach (T item in Items)
+            for (int i = 0; i < Count; i++)
             {
+                ref RangeItem<T> item = ref _items[i];
+
                 if (item.Address >= endAddress)
                 {
                     break;
                 }
 
-                if (item.OverlapsWith(address, size))
+                if (item.OverlapsWith(address, endAddress))
                 {
                     if (outputIndex == output.Length)
                     {
                         Array.Resize(ref output, outputIndex + ArrayGrowthSize);
                     }
 
-                    output[outputIndex++] = item;
+                    output[outputIndex++] = item.Value;
                 }
             }
 
@@ -192,11 +284,13 @@ namespace Ryujinx.Memory.Range
             // when none of the items on the list overlaps with each other.
             int outputIndex = 0;
 
-            int index = BinarySearch(address, size);
+            ulong endAddress = address + size;
+
+            int index = BinarySearch(address, endAddress);
 
             if (index >= 0)
             {
-                while (index > 0 && Items[index - 1].OverlapsWith(address, size))
+                while (index > 0 && _items[index - 1].OverlapsWith(address, endAddress))
                 {
                     index--;
                 }
@@ -208,9 +302,9 @@ namespace Ryujinx.Memory.Range
                         Array.Resize(ref output, outputIndex + ArrayGrowthSize);
                     }
 
-                    output[outputIndex++] = Items[index++];
+                    output[outputIndex++] = _items[index++].Value;
                 }
-                while (index < Items.Count && Items[index].OverlapsWith(address, size));
+                while (index < Count && _items[index].OverlapsWith(address, endAddress));
             }
 
             return outputIndex;
@@ -230,14 +324,14 @@ namespace Ryujinx.Memory.Range
 
             if (index >= 0)
             {
-                while (index > 0 && Items[index - 1].Address == address)
+                while (index > 0 && _items[index - 1].Address == address)
                 {
                     index--;
                 }
 
-                while (index < Items.Count)
+                while (index < Count)
                 {
-                    T overlap = Items[index++];
+                    ref RangeItem<T> overlap = ref _items[index++];
 
                     if (overlap.Address != address)
                     {
@@ -249,7 +343,7 @@ namespace Ryujinx.Memory.Range
                         Array.Resize(ref output, outputIndex + ArrayGrowthSize);
                     }
 
-                    output[outputIndex++] = overlap;
+                    output[outputIndex++] = overlap.Value;
                 }
             }
 
@@ -264,7 +358,7 @@ namespace Ryujinx.Memory.Range
         private int BinarySearch(ulong address)
         {
             int left  = 0;
-            int right = Items.Count - 1;
+            int right = Count - 1;
 
             while (left <= right)
             {
@@ -272,7 +366,7 @@ namespace Ryujinx.Memory.Range
 
                 int middle = left + (range >> 1);
 
-                T item = Items[middle];
+                ref RangeItem<T> item = ref _items[middle];
 
                 if (item.Address == address)
                 {
@@ -296,12 +390,12 @@ namespace Ryujinx.Memory.Range
         /// Performs binary search for items overlapping a given memory range.
         /// </summary>
         /// <param name="address">Start address of the range</param>
-        /// <param name="size">Size in bytes of the range</param>
+        /// <param name="endAddress">End address of the range</param>
         /// <returns>List index of the item, or complement index of nearest item with lower value on the list</returns>
-        private int BinarySearch(ulong address, ulong size)
+        private int BinarySearch(ulong address, ulong endAddress)
         {
             int left  = 0;
-            int right = Items.Count - 1;
+            int right = Count - 1;
 
             while (left <= right)
             {
@@ -309,9 +403,9 @@ namespace Ryujinx.Memory.Range
 
                 int middle = left + (range >> 1);
 
-                T item = Items[middle];
+                ref RangeItem<T> item = ref _items[middle];
 
-                if (item.OverlapsWith(address, size))
+                if (item.OverlapsWith(address, endAddress))
                 {
                     return middle;
                 }
@@ -331,12 +425,18 @@ namespace Ryujinx.Memory.Range
 
         public IEnumerator<T> GetEnumerator()
         {
-            return Items.GetEnumerator();
+            for (int i = 0; i < Count; i++)
+            {
+                yield return _items[i].Value;
+            }
         }
 
         IEnumerator IEnumerable.GetEnumerator()
         {
-            return Items.GetEnumerator();
+            for (int i = 0; i < Count; i++)
+            {
+                yield return _items[i].Value;
+            }
         }
     }
 }
\ No newline at end of file
diff --git a/Ryujinx.Memory/WindowsShared/EmulatedSharedMemoryWindows.cs b/Ryujinx.Memory/WindowsShared/EmulatedSharedMemoryWindows.cs
index 46399504..1417f7d5 100644
--- a/Ryujinx.Memory/WindowsShared/EmulatedSharedMemoryWindows.cs
+++ b/Ryujinx.Memory/WindowsShared/EmulatedSharedMemoryWindows.cs
@@ -41,10 +41,12 @@ namespace Ryujinx.Memory.WindowsShared
                 return Address < address + size && address < EndAddress;
             }
 
-            public void ExtendTo(ulong endAddress)
+            public void ExtendTo(ulong endAddress, RangeList<SharedMemoryMapping> list)
             {
                 EndAddress = endAddress;
                 Size = endAddress - Address;
+
+                list.UpdateEndAddress(this);
             }
 
             public void AddBlocks(IEnumerable<int> blocks)
@@ -300,14 +302,14 @@ namespace Ryujinx.Memory.WindowsShared
 
                     _mappings.Remove(endOverlap);
 
-                    startOverlap.ExtendTo(endOverlap.EndAddress);
+                    startOverlap.ExtendTo(endOverlap.EndAddress, _mappings);
 
                     startOverlap.AddBlocks(blocks);
                     startOverlap.AddBlocks(endOverlap.Blocks);
                 }
                 else if (startOverlap != null)
                 {
-                    startOverlap.ExtendTo(endAddress);
+                    startOverlap.ExtendTo(endAddress, _mappings);
 
                     startOverlap.AddBlocks(blocks);
                 }
@@ -317,7 +319,7 @@ namespace Ryujinx.Memory.WindowsShared
 
                     if (endOverlap != null)
                     {
-                        mapping.ExtendTo(endOverlap.EndAddress);
+                        mapping.ExtendTo(endOverlap.EndAddress, _mappings);
 
                         mapping.AddBlocks(endOverlap.Blocks);
 
@@ -381,6 +383,7 @@ namespace Ryujinx.Memory.WindowsShared
                         if (mapping.EndAddress > endAddress)
                         {
                             var newMapping = (SharedMemoryMapping)mapping.Split(endAddress);
+                            _mappings.UpdateEndAddress(mapping);
                             _mappings.Add(newMapping);
 
                             if ((endAddress & MappingMask) != 0)
@@ -400,7 +403,9 @@ namespace Ryujinx.Memory.WindowsShared
                         // If the first region starts before the decommit address, split it by modifying its end address.
                         if (mapping.Address < address)
                         {
+                            var oldMapping = mapping;
                             mapping = (SharedMemoryMapping)mapping.Split(address);
+                            _mappings.UpdateEndAddress(oldMapping);
 
                             if ((address & MappingMask) != 0)
                             {
diff --git a/Ryujinx.Memory/WindowsShared/PlaceholderList.cs b/Ryujinx.Memory/WindowsShared/PlaceholderList.cs
index be8cef9c..848e410e 100644
--- a/Ryujinx.Memory/WindowsShared/PlaceholderList.cs
+++ b/Ryujinx.Memory/WindowsShared/PlaceholderList.cs
@@ -32,10 +32,12 @@ namespace Ryujinx.Memory.WindowsShared
                 return Address < address + size && address < EndAddress;
             }
 
-            public void ExtendTo(ulong end)
+            public void ExtendTo(ulong end, RangeList<PlaceholderBlock> list)
             {
                 EndAddress = end;
                 Size = end - Address;
+
+                list.UpdateEndAddress(this);
             }
         }
 
@@ -126,13 +128,13 @@ namespace Ryujinx.Memory.WindowsShared
 
             if (overlapStart && first.IsGranular)
             {
-                first.ExtendTo(endId);
+                first.ExtendTo(endId, _placeholders);
             }
             else
             {
                 if (overlapStart)
                 {
-                    first.ExtendTo(id);
+                    first.ExtendTo(id, _placeholders);
                 }
 
                 _placeholders.Add(new PlaceholderBlock(id, endId - id, true));
@@ -189,7 +191,7 @@ namespace Ryujinx.Memory.WindowsShared
 
                 if (block.Address < id && blockEnd > id)
                 {
-                    block.ExtendTo(id);
+                    block.ExtendTo(id, _placeholders);
                     extendBlock = null;
                 }
                 else
@@ -223,7 +225,7 @@ namespace Ryujinx.Memory.WindowsShared
                 else
                 {
                     extendFrom = extendBlock.Address;
-                    extendBlock.ExtendTo(block.IsGranular ? extent : block.EndAddress);
+                    extendBlock.ExtendTo(block.IsGranular ? extent : block.EndAddress, _placeholders);
                 }
 
                 if (block.IsGranular)