Misc. CPU improvements (#519)

* Fix and simplify TranslatorCache

* Fix some assignment alignments, remove some unused usings

* Changes to ILEmitter, separate it from ILEmitterCtx

* Rename ILEmitter to ILMethodBuilder

* Rename LdrLit and *_Fix opcodes

* Revert TranslatorCache impl to the more performant one, fix a few issues with it

* Allow EmitOpCode to be called even after everything has been emitted

* Make Emit and AdvanceOpCode private, simplify it a bit now that it starts emiting from the entry point

* Remove unneeded temp use

* Add missing exit call on TestExclusive

* Use better hash

* Implement the == and != operators

1 files changed, 16 insertions, 9 deletions

diff --git a/ChocolArm64/TranslatorCache.cs b/ChocolArm64/TranslatorCache.cs
index 7d650357..93da555e 100644
--- a/ChocolArm64/TranslatorCache.cs
+++ b/ChocolArm64/TranslatorCache.cs
@@ -9,8 +9,8 @@ namespace ChocolArm64
 {
     class TranslatorCache
     {
-        //Maximum size of the cache, in bytes, measured in ARM code size.
-        private const int MaxTotalSize = 4 * 1024 * 256;
+        //Maximum size of the cache, the unit used is completely arbitrary.
+        private const int MaxTotalSize = 0x800000;
 
         //Minimum time required in milliseconds for a method to be eligible for deletion.
         private const int MinTimeDelta = 2 * 60000;
@@ -63,10 +63,10 @@ namespace ChocolArm64
         {
             ClearCacheIfNeeded();
 
-            _totalSize += size;
-
             lock (_sortedCache)
             {
+                _totalSize += size;
+
                 LinkedListNode<long> node = _sortedCache.AddLast(position);
 
                 CacheBucket newBucket = new CacheBucket(subroutine, node, size);
@@ -98,11 +98,18 @@ namespace ChocolArm64
                     {
                         try
                         {
-                            bucket.CallCount = 0;
-
-                            _sortedCache.Remove(bucket.Node);
-
-                            bucket.UpdateNode(_sortedCache.AddLast(position));
+                            //The bucket value on the dictionary may have changed between the
+                            //time we get the value from the dictionary, and we acquire the
+                            //lock. So we need to ensure we are working with the latest value,
+                            //we can do that by getting the value again, inside the lock.
+                            if (_cache.TryGetValue(position, out CacheBucket latestBucket))
+                            {
+                                latestBucket.CallCount = 0;
+
+                                _sortedCache.Remove(latestBucket.Node);
+
+                                latestBucket.UpdateNode(_sortedCache.AddLast(position));
+                            }
                         }
                         finally
                         {