[GPU] XXH3 hash instead of XXH64

src/xenia/base/hash.h

@@ -17,7 +17,7 @@ namespace hash {
 
 // For use in unordered_sets and unordered_maps (primarily multisets and
 // multimaps, with manual collision resolution), where the hash is calculated
-// externally (for instance, as XXH64), possibly requiring context data rather
+// externally (for instance, as XXH3), possibly requiring context data rather
 // than a pure function to calculate the hash
 template <typename Key>
 struct IdentityHasher {

src/xenia/base/xxhash.h

@@ -0,0 +1,21 @@
+/**
+ ******************************************************************************
+ * Xenia : Xbox 360 Emulator Research Project                                 *
+ ******************************************************************************
+ * Copyright 2020 Ben Vanik. All rights reserved.                             *
+ * Released under the BSD license - see LICENSE in the root for more details. *
+ ******************************************************************************
+ */
+
+#ifndef XENIA_BASE_XXHASH_H_
+#define XENIA_BASE_XXHASH_H_
+
+#define XXH_INLINE_ALL
+
+// Can't use XXH_X86DISPATCH because XXH is calculated on multiple threads,
+// while the dispatch writes the result (multiple pointers without any
+// synchronization) to XXH_g_dispatch at the first call.
+
+#include "third_party/xxhash/xxhash.h"
+
+#endif  // XENIA_BASE_XXHASH_H_