Changed: Redefined thresholds on GetHashCodeUnstableLower in terms of nuint

Author: Sewer56

src/Reloaded.Memory/Internals/Algorithms/UnstableStringHash.cs

@@ -40,12 +40,10 @@ internal static unsafe nuint GetHashCodeUnstable(this ReadOnlySpan<char> text)
         // For our use of hashing file paths, this is okay, as files with different names but same extension
         // would still hash differently. If I were to PR this to runtime though, this would need fixing.
 
-        // Over 4 Vec256 regs (32 * 4 = 128 bytes)
-        if (Vector256.IsHardwareAccelerated && length >= (sizeof(Vector256<ulong>) / sizeof(char)) * 4)
+        if (Vector256.IsHardwareAccelerated && length >= sizeof(nuint) * 8)
             return text.UnstableHashVec256();
 
-        // Over 4 Vec128 regs (16 * 4 = 64 bytes)
-        if (Vector128.IsHardwareAccelerated && length >= (sizeof(Vector128<ulong>) / sizeof(char)) * 4)
+        if (Vector128.IsHardwareAccelerated && length >= sizeof(nuint) * 4)
             return text.UnstableHashVec128();
 #endif
 

src/Reloaded.Memory/Internals/Algorithms/UnstableStringHashLower.cs

@@ -35,21 +35,15 @@ internal static unsafe nuint GetHashCodeUnstableLower(this ReadOnlySpan<char> te
     {
 #if NET7_0_OR_GREATER
         var length = text.Length; // Span has no guarantee of null terminator.
-        // For short strings below size of nuint, we need separate approach; so we use legacy runtime approach
-        // for said cold case.
-
-        // Note: The `/ sizeof(char)` accounts that length is measured in 2-byte chars, not bytes.
 
         // Note. In these SIMD implementations we leave some (< sizeof(nuint)) data from the hash.
         // For our use of hashing file paths, this is okay, as files with different names but same extension
         // would still hash differently. If I were to PR this to runtime though, this would need fixing.
 
-        // Over 4 Vec256 regs (32 * 4 = 128 bytes)
-        if (Vector256.IsHardwareAccelerated && length >= (sizeof(Vector256<ulong>) / sizeof(char)) * 4)
+        if (Vector256.IsHardwareAccelerated && length >= sizeof(nuint) * 8)
             return text.UnstableHashVec256Lower();
 
-        // Over 4 Vec128 regs (16 * 4 = 64 bytes)
-        if (Vector128.IsHardwareAccelerated && length >= (sizeof(Vector128<ulong>) / sizeof(char)) * 4)
+        if (Vector128.IsHardwareAccelerated && length >= sizeof(nuint) * 4)
             return text.UnstableHashVec128Lower();
 #endif