Imported Upstream version 6.4.0.137

Former-commit-id: 943baa9f16a098c33e129777827f3a9d20da00d6

mcs/class/System.Private.CoreLib/System/String.cs

@@ -0,0 +1,197 @@
+using System.Runtime.CompilerServices;
+using Internal.Runtime.CompilerServices;
+
+namespace System
+{
+	partial class String
+	{
+		[NonSerialized]
+		int _stringLength;
+		[NonSerialized]
+		char _firstChar;
+
+		[Intrinsic]
+		public static readonly String Empty;
+
+		public int Length => _stringLength;
+
+		[IndexerName ("Chars")]
+		public char this [int index] {
+			[Intrinsic]
+			get {
+				if ((uint)index >= _stringLength)
+					ThrowHelper.ThrowIndexOutOfRangeException ();
+
+				return Unsafe.Add (ref _firstChar, index);
+			}
+		}
+
+		public static String Intern (String str)
+		{
+			if (str == null)
+				throw new ArgumentNullException(nameof(str));
+
+			return InternalIntern (str);
+		}
+
+		public static String IsInterned (String str)
+		{
+			if (str == null)
+				throw new ArgumentNullException(nameof(str));
+
+			return InternalIsInterned (str);
+		}
+
+		[MethodImplAttribute (MethodImplOptions.InternalCall)]
+		internal extern static String FastAllocateString (int length);
+
+		[MethodImplAttribute (MethodImplOptions.InternalCall)]
+		extern static String InternalIsInterned (String str);
+
+		[MethodImplAttribute (MethodImplOptions.InternalCall)]
+		extern static String InternalIntern (String str);
+
+		// TODO: Should be pointing to Buffer instead
+		#region Runtime method-to-ir dependencies
+
+		static unsafe void memset (byte *dest, int val, int len)
+		{
+			if (len < 8) {
+				while (len != 0) {
+					*dest = (byte)val;
+					++dest;
+					--len;
+				}
+				return;
+			}
+			if (val != 0) {
+				val = val | (val << 8);
+				val = val | (val << 16);
+			}
+			// align to 4
+			int rest = (int)dest & 3;
+			if (rest != 0) {
+				rest = 4 - rest;
+				len -= rest;
+				do {
+					*dest = (byte)val;
+					++dest;
+					--rest;
+				} while (rest != 0);
+			}
+			while (len >= 16) {
+				((int*)dest) [0] = val;
+				((int*)dest) [1] = val;
+				((int*)dest) [2] = val;
+				((int*)dest) [3] = val;
+				dest += 16;
+				len -= 16;
+			}
+			while (len >= 4) {
+				((int*)dest) [0] = val;
+				dest += 4;
+				len -= 4;
+			}
+			// tail bytes
+			while (len > 0) {
+				*dest = (byte)val;
+				dest++;
+				len--;
+			}
+		}
+
+		static unsafe void memcpy (byte *dest, byte *src, int size)
+		{
+			Buffer.Memcpy (dest, src, size);
+		}
+
+		/* Used by the runtime */
+		internal static unsafe void bzero (byte *dest, int len) {
+			memset (dest, 0, len);
+		}
+
+		internal static unsafe void bzero_aligned_1 (byte *dest, int len) {
+			((byte*)dest) [0] = 0;
+		}
+
+		internal static unsafe void bzero_aligned_2 (byte *dest, int len) {
+			((short*)dest) [0] = 0;
+		}
+
+		internal static unsafe void bzero_aligned_4 (byte *dest, int len) {
+			((int*)dest) [0] = 0;
+		}
+
+		internal static unsafe void bzero_aligned_8 (byte *dest, int len) {
+			((long*)dest) [0] = 0;
+		}
+
+		internal static unsafe void memcpy_aligned_1 (byte *dest, byte *src, int size) {
+			((byte*)dest) [0] = ((byte*)src) [0];
+		}
+
+		internal static unsafe void memcpy_aligned_2 (byte *dest, byte *src, int size) {
+			((short*)dest) [0] = ((short*)src) [0];
+		}
+
+		internal static unsafe void memcpy_aligned_4 (byte *dest, byte *src, int size) {
+			((int*)dest) [0] = ((int*)src) [0];
+		}
+
+		internal static unsafe void memcpy_aligned_8 (byte *dest, byte *src, int size) {
+			((long*)dest) [0] = ((long*)src) [0];
+		}
+
+		#endregion
+
+		// Certain constructors are redirected to CreateString methods with
+		// matching argument list. The this pointer should not be used.
+		//
+		// TODO: Update runtime to call Ctor directly
+
+		unsafe String CreateString (sbyte* value)
+		{
+			return Ctor (value);
+		}
+
+		unsafe String CreateString (sbyte* value, int startIndex, int length)
+		{
+			return Ctor (value, startIndex, length);
+		}
+
+		unsafe String CreateString (char* value)
+		{
+			return Ctor (value);
+		}
+
+		unsafe String CreateString (char* value, int startIndex, int length)
+		{
+			return Ctor (value, startIndex, length);
+		}
+
+		String CreateString (char[] val, int startIndex, int length)
+		{
+			return Ctor (val, startIndex, length);
+		}
+
+		String CreateString (char [] val)
+		{
+			return Ctor (val);
+		}
+
+		String CreateString (char c, int count)
+		{
+			return Ctor (c, count);
+		}
+
+		unsafe String CreateString (sbyte* value, int startIndex, int length, System.Text.Encoding enc)
+		{
+			return Ctor (value, startIndex, length, enc);
+		}
+
+		String CreateString (ReadOnlySpan<char> value)
+		{
+			return Ctor (value);
+		}
+	}
+}