Add TLV allocator FCall

Author: am11

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

@@ -557,7 +557,9 @@ internal static object BoxImpl(MethodTable* typeMT, ref byte unboxedData)
             Debug.Assert(typeMT != null);
             Debug.Assert(typeMT->IsValueType);
 
-            object boxed = RuntimeTypeHandle.InternalAllocNoChecks(typeMT);
+            object boxed = RuntimeTypeHandle.GetThreadLocalAllocInternal(typeMT) ??
+                RuntimeTypeHandle.InternalAllocNoChecks(typeMT);
+
             if (typeMT->ContainsGCPointers)
             {
                 Buffer.BulkMoveWithWriteBarrier(ref boxed.GetRawData(), ref unboxedData,

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

@@ -449,6 +449,9 @@ 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);
+
         [MethodImpl(MethodImplOptions.InternalCall)]
         internal static extern int GetArrayRank(RuntimeType type);
 

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)

src/coreclr/vm/runtimehandles.cpp

@@ -1143,6 +1143,35 @@ FCIMPL2(FC_BOOL_RET, RuntimeTypeHandle::CompareCanonicalHandles, ReflectClassBas
 }
 FCIMPLEND
 
+FCIMPL1(Object*, RuntimeTypeHandle::GetThreadLocalAllocInternal, MethodTable* pMT)
+{
+    FCALL_CONTRACT;
+
+    _ASSERTE(pMT != nullptr);
+    _ASSERTE(pMT->IsValueType());
+    _ASSERTE(GCHeapUtilities::UseThreadAllocationContexts());
+
+    SIZE_T size = pMT->GetBaseSize();
+    _ASSERTE(size % DATA_ALIGNMENT == 0);
+
+    ee_alloc_context* allocContext = &t_runtime_thread_locals.alloc_context;
+    BYTE* allocPtr = allocContext->m_GCAllocContext.alloc_ptr;
+    BYTE* limit = allocContext->getCombinedLimit();
+
+    if ((SIZE_T)(limit - allocPtr) < size)
+    {
+        return NULL; // Fall back to slow path in managed
+    }
+
+    allocContext->m_GCAllocContext.alloc_ptr = allocPtr + size;
+    Object* obj = reinterpret_cast<Object*>(allocPtr);
+    obj->SetMethodTable(pMT);
+    _ASSERTE(obj->HasEmptySyncBlockInfo());
+
+    return obj;
+}
+FCIMPLEND
+
 FCIMPL1(FC_BOOL_RET, RuntimeTypeHandle::IsGenericVariable, PTR_ReflectClassBaseObject pTypeUNSAFE)
 {
     FCALL_CONTRACT;

src/coreclr/vm/runtimehandles.h

@@ -125,6 +125,7 @@ class RuntimeTypeHandle
     FCDECL1(FC_BOOL_RET, ContainsGenericVariables, PTR_ReflectClassBaseObject pType);
 
     static FCDECL2(FC_BOOL_RET, CompareCanonicalHandles, PTR_ReflectClassBaseObject pLeft, PTR_ReflectClassBaseObject pRight);
+    static FCDECL1(Object*, GetThreadLocalAllocInternal, MethodTable* pMT);
 
     static FCDECL1(EnregisteredTypeHandle, GetElementTypeHandle, EnregisteredTypeHandle th);
     static FCDECL1(INT32, GetNumVirtuals, ReflectClassBaseObject *pType);