Convert JIT_Box* to C#

src/coreclr/System.Private.CoreLib/src/System/Runtime/CompilerServices/CastHelpers.cs

@@ -517,6 +517,45 @@ private static void ArrayTypeCheck_Helper(object obj, void* elementType)
             }
         }
 
+        // Helpers for boxing
+        [DebuggerHidden]
+        internal static object? Box_Nullable(MethodTable* srcMT, ref byte nullableData)
+        {
+            Debug.Assert(srcMT->IsNullable);
+
+            // If 'hasValue' is false, return null.
+            if (!Unsafe.As<byte, bool>(ref nullableData))
+                return null;
+
+            // Allocate a new instance of the T in Nullable<T>.
+            MethodTable* dstMT = srcMT->InstantiationArg0();
+            ref byte srcValue = ref Unsafe.Add(ref nullableData, srcMT->NullableValueAddrOffset);
+
+            // Delegate to non-nullable boxing implementation
+            return Box(dstMT, ref srcValue);
+        }
+
+        [DebuggerHidden]
+        internal static object Box(MethodTable* typeMT, ref byte unboxedData)
+        {
+            Debug.Assert(typeMT != null);
+            Debug.Assert(typeMT->IsValueType);
+
+            object boxed = RuntimeTypeHandle.GetThreadLocalAllocInternal(typeMT, out uint bytes) ??
+                RuntimeTypeHandle.InternalAllocNoChecks(typeMT);
+
+            if (typeMT->ContainsGCPointers)
+            {
+                Buffer.BulkMoveWithWriteBarrier(ref boxed.GetRawData(), ref unboxedData, bytes);
+            }
+            else
+            {
+                SpanHelpers.Memmove(ref boxed.GetRawData(), ref unboxedData, bytes);
+            }
+
+            return boxed;
+        }
+
         // Helpers for Unboxing
 #if FEATURE_TYPEEQUIVALENCE
         [DebuggerHidden]
@@ -615,27 +654,8 @@ internal static void Unbox_Nullable(ref byte destPtr, MethodTable* typeMT, objec
         [DebuggerHidden]
         internal static object? ReboxFromNullable(MethodTable* srcMT, object src)
         {
-            Debug.Assert(srcMT->IsNullable);
-
             ref byte nullableData = ref src.GetRawData();
-
-            // If 'hasValue' is false, return null.
-            if (!Unsafe.As<byte, bool>(ref nullableData))
-                return null;
-
-            // Allocate a new instance of the T in Nullable<T>.
-            MethodTable* dstMT = srcMT->InstantiationArg0();
-            object dst = RuntimeTypeHandle.InternalAlloc(dstMT);
-
-            // Copy data from the Nullable<T>.
-            ref byte srcData = ref Unsafe.Add(ref nullableData, srcMT->NullableValueAddrOffset);
-            ref byte dstData = ref RuntimeHelpers.GetRawData(dst);
-            if (dstMT->ContainsGCPointers)
-                Buffer.BulkMoveWithWriteBarrier(ref dstData, ref srcData, dstMT->GetNumInstanceFieldBytesIfContainsGCPointers());
-            else
-                SpanHelpers.Memmove(ref dstData, ref srcData, dstMT->GetNumInstanceFieldBytes());
-
-            return dst;
+            return Box_Nullable(srcMT, ref nullableData);
         }
 
         [DebuggerHidden]

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

@@ -445,8 +445,8 @@ internal static unsafe bool ObjectHasComponentSize(object obj)
         /// <param name="data">A reference to the data to box.</param>
         /// <returns>A boxed instance of the value at <paramref name="data"/>.</returns>
         /// <remarks>This method includes proper handling for nullable value types as well.</remarks>
-        [MethodImpl(MethodImplOptions.InternalCall)]
-        internal static extern unsafe object? Box(MethodTable* methodTable, ref byte data);
+        internal static unsafe object? Box(MethodTable* methodTable, ref byte data) =>
+            methodTable->IsNullable ? CastHelpers.Box_Nullable(methodTable, ref data) : CastHelpers.Box(methodTable, ref data);
 
         // Given an object reference, returns its MethodTable*.
         //

src/coreclr/System.Private.CoreLib/src/System/RuntimeHandles.cs

@@ -299,6 +299,7 @@ internal static object InternalAlloc(RuntimeType type)
         [LibraryImport(RuntimeHelpers.QCall, EntryPoint = "RuntimeTypeHandle_InternalAlloc")]
         private static unsafe partial void InternalAlloc(MethodTable* pMT, ObjectHandleOnStack result);
 
+        [MethodImpl(MethodImplOptions.NoInlining)]
         internal static object InternalAllocNoChecks(MethodTable* pMT)
         {
             object? result = null;
@@ -449,6 +450,9 @@ public ModuleHandle GetModuleHandle()
         [MethodImpl(MethodImplOptions.InternalCall)]
         internal static extern bool CompareCanonicalHandles(RuntimeType left, RuntimeType right);
 
+        [MethodImpl(MethodImplOptions.InternalCall)]
+        internal static extern object? GetThreadLocalAllocInternal(MethodTable* pMT, out uint size);
+
         [MethodImpl(MethodImplOptions.InternalCall)]
         internal static extern int GetArrayRank(RuntimeType type);
 

src/coreclr/inc/jithelpers.h

@@ -132,11 +132,11 @@
 
     JITHELPER(CORINFO_HELP_ISINSTANCEOF_EXCEPTION, JIT_IsInstanceOfException, METHOD__NIL)
 
-    DYNAMICJITHELPER(CORINFO_HELP_BOX,          JIT_Box,            METHOD__NIL)
-    JITHELPER(CORINFO_HELP_BOX_NULLABLE,        JIT_Box,            METHOD__NIL)
-    DYNAMICJITHELPER(CORINFO_HELP_UNBOX,        NULL,               METHOD__CASTHELPERS__UNBOX)
-    DYNAMICJITHELPER(CORINFO_HELP_UNBOX_TYPETEST,NULL,              METHOD__CASTHELPERS__UNBOX_TYPETEST)
-    DYNAMICJITHELPER(CORINFO_HELP_UNBOX_NULLABLE,NULL,              METHOD__CASTHELPERS__UNBOX_NULLABLE)
+    DYNAMICJITHELPER(CORINFO_HELP_BOX,               NULL,          METHOD__CASTHELPERS__BOX)
+    DYNAMICJITHELPER(CORINFO_HELP_BOX_NULLABLE,      NULL,          METHOD__CASTHELPERS__BOX_NULLABLE)
+    DYNAMICJITHELPER(CORINFO_HELP_UNBOX,             NULL,          METHOD__CASTHELPERS__UNBOX)
+    DYNAMICJITHELPER(CORINFO_HELP_UNBOX_TYPETEST,    NULL,          METHOD__CASTHELPERS__UNBOX_TYPETEST)
+    DYNAMICJITHELPER(CORINFO_HELP_UNBOX_NULLABLE,    NULL,          METHOD__CASTHELPERS__UNBOX_NULLABLE)
 
     DYNAMICJITHELPER(CORINFO_HELP_GETREFANY,    NULL,               METHOD__TYPED_REFERENCE__GETREFANY)
     DYNAMICJITHELPER(CORINFO_HELP_ARRADDR_ST,   NULL,               METHOD__CASTHELPERS__STELEMREF)

src/coreclr/vm/amd64/JitHelpers_Slow.asm

@@ -41,7 +41,6 @@ endif
 
 JIT_NEW                 equ     ?JIT_New@@YAPEAVObject@@PEAUCORINFO_CLASS_STRUCT_@@@Z
 CopyValueClassUnchecked equ     ?CopyValueClassUnchecked@@YAXPEAX0PEAVMethodTable@@@Z
-JIT_Box                 equ     ?JIT_Box@@YAPEAVObject@@PEAUCORINFO_CLASS_STRUCT_@@PEAX@Z
 g_pStringClass          equ     ?g_pStringClass@@3PEAVMethodTable@@EA
 FramedAllocateString    equ     ?FramedAllocateString@@YAPEAVStringObject@@K@Z
 JIT_NewArr1             equ     ?JIT_NewArr1@@YAPEAVObject@@PEAUCORINFO_CLASS_STRUCT_@@_J@Z
@@ -50,7 +49,6 @@ INVALIDGCVALUE          equ     0CCCCCCCDh
 
 extern JIT_NEW:proc
 extern CopyValueClassUnchecked:proc
-extern JIT_Box:proc
 extern g_pStringClass:QWORD
 extern FramedAllocateString:proc
 extern JIT_NewArr1:proc
@@ -197,69 +195,6 @@ LEAF_ENTRY JIT_TrialAllocSFastSP, _TEXT
         jmp     JIT_NEW
 LEAF_END JIT_TrialAllocSFastSP, _TEXT
 
-; HCIMPL2(Object*, JIT_Box, CORINFO_CLASS_HANDLE type, void* unboxedData)
-NESTED_ENTRY JIT_BoxFastUP, _TEXT
-
-        ; m_BaseSize is guaranteed to be a multiple of 8.
-        mov     r8d, [rcx + OFFSET__MethodTable__m_BaseSize]
-
-        inc     [g_global_alloc_lock]
-        jnz     JIT_Box
-
-        mov     rax, [g_global_alloc_context + OFFSETOF__ee_alloc_context__alloc_ptr]       ; alloc_ptr
-        mov     r10, [g_global_alloc_context + OFFSETOF__ee_alloc_context__m_CombinedLimit] ; m_CombinedLimit
-
-        add     r8, rax
-
-        cmp     r8, r10
-        ja      NoAlloc
-
-        test    rdx, rdx
-        je      NullRef
-
-        mov     qword ptr [g_global_alloc_context + OFFSETOF__ee_alloc_context__alloc_ptr], r8 ; update the alloc ptr
-        mov     [rax], rcx
-        mov     [g_global_alloc_lock], -1
-
-        ; Check whether the object contains pointers
-        test    dword ptr [rcx + OFFSETOF__MethodTable__m_dwFlags], MethodTable__enum_flag_ContainsGCPointers
-        jnz     ContainsPointers
-
-        ; We have no pointers - emit a simple inline copy loop
-
-        mov     ecx, [rcx + OFFSET__MethodTable__m_BaseSize]
-        sub     ecx, 18h  ; sizeof(ObjHeader) + sizeof(Object) + last slot
-
-    CopyLoop:
-        mov     r8, [rdx+rcx]
-        mov     [rax+rcx+8], r8
-
-        sub     ecx, 8
-        jge     CopyLoop
-        REPRET
-
-    ContainsPointers:
-
-        ; Do call to CopyValueClassUnchecked(object, data, pMT)
-
-        push_vol_reg rax
-        alloc_stack 20h
-        END_PROLOGUE
-
-        mov     r8, rcx
-        lea     rcx, [rax + 8]
-        call    CopyValueClassUnchecked
-
-        add     rsp, 20h
-        pop     rax
-        ret
-
-    NoAlloc:
-    NullRef:
-        mov     [g_global_alloc_lock], -1
-        jmp     JIT_Box
-NESTED_END JIT_BoxFastUP, _TEXT
-
 LEAF_ENTRY AllocateStringFastUP, _TEXT
 
         ; We were passed the number of characters in ECX

src/coreclr/vm/arm/stubs.cpp

@@ -1652,7 +1652,6 @@ void InitJITHelpers1()
         SetJitHelperFunction(CORINFO_HELP_NEWSFAST, JIT_NewS_MP_FastPortable);
         SetJitHelperFunction(CORINFO_HELP_NEWARR_1_VC, JIT_NewArr1VC_MP_FastPortable);
         SetJitHelperFunction(CORINFO_HELP_NEWARR_1_OBJ, JIT_NewArr1OBJ_MP_FastPortable);
-        SetJitHelperFunction(CORINFO_HELP_BOX, JIT_Box_MP_FastPortable);
 
         ECall::DynamicallyAssignFCallImpl(GetEEFuncEntryPoint(AllocateString_MP_FastPortable), ECall::FastAllocateString);
     }

src/coreclr/vm/arm64/stubs.cpp

@@ -878,7 +878,6 @@ void InitJITHelpers1()
             SetJitHelperFunction(CORINFO_HELP_NEWSFAST_ALIGN8, JIT_NewS_MP_FastPortable);
             SetJitHelperFunction(CORINFO_HELP_NEWARR_1_VC, JIT_NewArr1VC_MP_FastPortable);
             SetJitHelperFunction(CORINFO_HELP_NEWARR_1_OBJ, JIT_NewArr1OBJ_MP_FastPortable);
-            SetJitHelperFunction(CORINFO_HELP_BOX, JIT_Box_MP_FastPortable);
 
             ECall::DynamicallyAssignFCallImpl(GetEEFuncEntryPoint(AllocateString_MP_FastPortable), ECall::FastAllocateString);
         }

src/coreclr/vm/corelib.h

@@ -1249,10 +1249,12 @@ DEFINE_METHOD(CASTHELPERS, CHKCASTANY,       ChkCastAny,                  SM_Ptr
 DEFINE_METHOD(CASTHELPERS, CHKCASTINTERFACE, ChkCastInterface,            SM_PtrVoid_Obj_RetObj)
 DEFINE_METHOD(CASTHELPERS, CHKCASTCLASS,     ChkCastClass,                SM_PtrVoid_Obj_RetObj)
 DEFINE_METHOD(CASTHELPERS, CHKCASTCLASSSPECIAL, ChkCastClassSpecial,      SM_PtrVoid_Obj_RetObj)
+DEFINE_METHOD(CASTHELPERS, BOX,              Box,                         NoSig)
 DEFINE_METHOD(CASTHELPERS, UNBOX,            Unbox,                       NoSig)
 DEFINE_METHOD(CASTHELPERS, STELEMREF,        StelemRef,                   SM_ArrObject_IntPtr_Obj_RetVoid)
 DEFINE_METHOD(CASTHELPERS, LDELEMAREF,       LdelemaRef,                  SM_ArrObject_IntPtr_PtrVoid_RetRefObj)
 DEFINE_METHOD(CASTHELPERS, ARRAYTYPECHECK,   ArrayTypeCheck,              SM_Obj_Array_RetVoid)
+DEFINE_METHOD(CASTHELPERS, BOX_NULLABLE,     Box_Nullable,                NoSig)
 DEFINE_METHOD(CASTHELPERS, UNBOX_NULLABLE,   Unbox_Nullable,              NoSig)
 DEFINE_METHOD(CASTHELPERS, UNBOX_TYPETEST,   Unbox_TypeTest,              NoSig)
 

src/coreclr/vm/ecalllist.h

@@ -97,6 +97,7 @@ FCFuncStart(gCOMTypeHandleFuncs)
     FCFuncElement("ContainsGenericVariables", RuntimeTypeHandle::ContainsGenericVariables)
     FCFuncElement("IsUnmanagedFunctionPointer", RuntimeTypeHandle::IsUnmanagedFunctionPointer)
     FCFuncElement("CompareCanonicalHandles", RuntimeTypeHandle::CompareCanonicalHandles)
+    FCFuncElement("GetThreadLocalAllocInternal", RuntimeTypeHandle::GetThreadLocalAllocInternal)
 FCFuncEnd()
 
 FCFuncStart(gMetaDataImport)
@@ -337,7 +338,6 @@ FCFuncStart(gRuntimeHelpers)
     FCFuncElement("TryEnsureSufficientExecutionStack", ReflectionInvocation::TryEnsureSufficientExecutionStack)
     FCFuncElement("AllocTailCallArgBufferWorker", TailCallHelp::AllocTailCallArgBufferWorker)
     FCFuncElement("GetTailCallInfo", TailCallHelp::GetTailCallInfo)
-    FCFuncElement("Box", JIT_Box)
 FCFuncEnd()
 
 FCFuncStart(gMethodTableFuncs)