Intrinsify Object.MemberwiseClone() (#46243)

dotnet · Dec 27, 2020 · 86047aa · 86047aa
1 parent 4f020cb
commit 86047aa
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Showing 4 changed files with 11 additions and 1 deletion.
diff --git a/src/coreclr/System.Private.CoreLib/src/System/Object.CoreCLR.cs b/src/coreclr/System.Private.CoreLib/src/System/Object.CoreCLR.cs
@@ -16,6 +16,7 @@ public partial class Object
         // object.  This is always a shallow copy of the instance. The method is protected
         // so that other object may only call this method on themselves.  It is intended to
         // support the ICloneable interface.
+        [Intrinsic]
         protected unsafe object MemberwiseClone()
         {
             object clone = RuntimeHelpers.AllocateUninitializedClone(this);

diff --git a/src/coreclr/jit/gentree.cpp b/src/coreclr/jit/gentree.cpp
@@ -17759,7 +17759,8 @@ CORINFO_CLASS_HANDLE Compiler::gtGetClassHandle(GenTree* tree, bool* pIsExact, b
             GenTreeCall* call = tree->AsCall();
             if (call->gtFlags & CORINFO_FLG_JIT_INTRINSIC)
             {
-                if (lookupNamedIntrinsic(call->gtCallMethHnd) == NI_System_Array_Clone)
+                NamedIntrinsic ni = lookupNamedIntrinsic(call->gtCallMethHnd);
+                if ((ni == NI_System_Array_Clone) || (ni == NI_System_Object_MemberwiseClone))
                 {
                     objClass = gtGetClassHandle(call->gtCallThisArg->GetNode(), pIsExact, pIsNonNull);
                     break;

diff --git a/src/coreclr/jit/importer.cpp b/src/coreclr/jit/importer.cpp
@@ -4816,6 +4816,13 @@ NamedIntrinsic Compiler::lookupNamedIntrinsic(CORINFO_METHOD_HANDLE method)
                 result = NI_System_Array_Clone;
             }
         }
+        else if (strcmp(className, "Object") == 0)
+        {
+            if (strcmp(methodName, "MemberwiseClone") == 0)
+            {
+                result = NI_System_Object_MemberwiseClone;
+            }
+        }
         else if (strcmp(className, "Type") == 0)
         {
             if (strcmp(methodName, "get_IsValueType") == 0)

diff --git a/src/coreclr/jit/namedintrinsiclist.h b/src/coreclr/jit/namedintrinsiclist.h
@@ -44,6 +44,7 @@ enum NamedIntrinsic : unsigned short
     NI_System_Type_IsAssignableFrom,
     NI_System_Type_IsAssignableTo,
     NI_System_Array_Clone,
+    NI_System_Object_MemberwiseClone,
 
     // These are used by HWIntrinsics but are defined more generally
     // to allow dead code optimization and handle the recursion case