Complete TryUnBox

Author: huoyaoyuan

src/coreclr/System.Private.CoreLib/src/System/Array.CoreCLR.cs

@@ -693,7 +693,22 @@ private unsafe void InternalSetValue(object? value, nint flattenedIndex)
                 // value class or primitive type
 
                 ref byte offsetDataRef = ref Unsafe.Add(ref arrayDataRef, flattenedIndex * pMethodTable->ComponentSize);
-                if (!RuntimeHelpers.TryUnboxInto(ref offsetDataRef, pElementMethodTable, value))
+                if (CastHelpers.IsInstanceOfAny(pElementMethodTable, value) != null)
+                {
+                    if (pElementMethodTable->IsNullable)
+                    {
+                        RuntimeHelpers.Unbox_Nullable(ref offsetDataRef, pElementMethodTable, value);
+                    }
+                    else if (pElementMethodTable->ContainsGCPointers)
+                    {
+                        Buffer.BulkMoveWithWriteBarrier(ref offsetDataRef, ref value.GetRawData(), pElementMethodTable->GetNumInstanceFieldBytes());
+                    }
+                    else
+                    {
+                        SpanHelpers.Memmove(ref offsetDataRef, ref value.GetRawData(), pElementMethodTable->GetNumInstanceFieldBytes());
+                    }
+                }
+                else
                 {
                     // Allow enum -> primitive conversion, disallow primitive -> enum conversion
                     MethodTable* thSrc = RuntimeHelpers.GetMethodTable(value);
@@ -707,7 +722,7 @@ private unsafe void InternalSetValue(object? value, nint flattenedIndex)
                     if (!RuntimeHelpers.CanPrimitiveWiden(srcType, targetType))
                         ThrowHelper.ThrowArgumentException(ExceptionResource.Arg_PrimitiveWiden);
 
-                    PrimitiveWiden(ref Unsafe.Unbox<byte>(value), ref offsetDataRef, srcType, targetType);
+                    PrimitiveWiden(ref value.GetRawData(), ref offsetDataRef, srcType, targetType);
                 }
             }
 

src/coreclr/System.Private.CoreLib/src/System/Runtime/CompilerServices/RuntimeHelpers.CoreCLR.cs

@@ -323,9 +323,6 @@ internal static unsafe bool ObjectHasComponentSize(object obj)
         [MethodImpl(MethodImplOptions.InternalCall)]
         internal static extern unsafe void Unbox_Nullable(ref byte destination, MethodTable* toTypeHnd, object? obj);
 
-        [MethodImpl(MethodImplOptions.InternalCall)]
-        internal static extern unsafe bool TryUnboxInto(ref byte destination, MethodTable* toTypeHnd, object obj);
-
         // Given an object reference, returns its MethodTable*.
         //
         // WARNING: The caller has to ensure that MethodTable* does not get unloaded. The most robust way

src/coreclr/vm/ecalllist.h

@@ -353,7 +353,6 @@ FCFuncEnd()
 #endif // FEATURE_COMINTEROP
 
 FCFuncStart(gCastHelpers)
-    FCFuncElement("CanCastTo_NoCacheLookup", ::IsInstanceOfAny_NoCacheLookup)
     FCFuncElement("IsInstanceOfAny_NoCacheLookup", ::IsInstanceOfAny_NoCacheLookup)
     FCFuncElement("ChkCastAny_NoCacheLookup", ::ChkCastAny_NoCacheLookup)
     FCFuncElement("Unbox_Helper", ::Unbox_Helper)