Inject IJW Copy Constructor calls in the JIT instead of in the IL stubs

docs/design/datacontracts/RuntimeTypeSystem.md

@@ -23,6 +23,7 @@ internal enum CorElementType
     // Values defined in ECMA-335 - II.23.1.16 Element types used in signatures
     // +
     Internal = 0x21, // Indicates that the next pointer sized number of bytes is the address of a TypeHandle. Signatures that contain the Internal CorElementType cannot exist in metadata that is saved into a serialized format.
+    CModInternal = 0x22, // Indicates that the next byte specifies if the modifier is required and the next pointer sized number of bytes after that is the address of a TypeHandle. Signatures that contain the CModInternal CorElementType cannot exist in metadata that is saved into a seralized format.
 }
 ```
 

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

@@ -360,6 +360,11 @@ internal static int EnumCompareTo<T>(T x, T y) where T : struct, Enum
             return x.CompareTo(y);
         }
 
+        // The body of this function will be created by the EE for the specific type.
+        // See getILIntrinsicImplementation for how this happens.
+        [Intrinsic]
+        internal static extern unsafe void CopyConstruct<T>(T* dest, T* src) where T : unmanaged;
+
         internal static ref byte GetRawData(this object obj) =>
             ref Unsafe.As<RawData>(obj).Data;
 

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

@@ -1315,75 +1315,6 @@ public IntPtr AddRef()
         }
     }  // class CleanupWorkListElement
 
-    internal unsafe struct CopyConstructorCookie
-    {
-        private void* m_source;
-
-        private nuint m_destinationOffset;
-
-        public delegate*<void*, void*, void> m_copyConstructor;
-
-        public delegate*<void*, void> m_destructor;
-
-        public CopyConstructorCookie* m_next;
-
-        [StackTraceHidden]
-        public void ExecuteCopy(void* destinationBase)
-        {
-            if (m_copyConstructor != null)
-            {
-                m_copyConstructor((byte*)destinationBase + m_destinationOffset, m_source);
-            }
-
-            if (m_destructor != null)
-            {
-                m_destructor(m_source);
-            }
-        }
-    }
-
-    internal unsafe struct CopyConstructorChain
-    {
-        public void* m_realTarget;
-        public CopyConstructorCookie* m_head;
-
-        public void Add(CopyConstructorCookie* cookie)
-        {
-            cookie->m_next = m_head;
-            m_head = cookie;
-        }
-
-        [ThreadStatic]
-        private static CopyConstructorChain s_copyConstructorChain;
-
-        public void Install(void* realTarget)
-        {
-            m_realTarget = realTarget;
-            s_copyConstructorChain = this;
-        }
-
-        [StackTraceHidden]
-        private void ExecuteCopies(void* destinationBase)
-        {
-            for (CopyConstructorCookie* current = m_head; current != null; current = current->m_next)
-            {
-                current->ExecuteCopy(destinationBase);
-            }
-        }
-
-        [UnmanagedCallersOnly]
-        [StackTraceHidden]
-        public static void* ExecuteCurrentCopiesAndGetTarget(void* destinationBase)
-        {
-            void* target = s_copyConstructorChain.m_realTarget;
-            s_copyConstructorChain.ExecuteCopies(destinationBase);
-            // Reset this instance to ensure we don't accidentally execute the copies again.
-            // All of the pointers point to the stack, so we don't need to free any memory.
-            s_copyConstructorChain = default;
-            return target;
-        }
-    }
-
     internal static partial class StubHelpers
     {
         [MethodImpl(MethodImplOptions.InternalCall)]

src/coreclr/ildasm/dasm.cpp

@@ -2088,6 +2088,9 @@ BYTE* PrettyPrintCABlobValue(PCCOR_SIGNATURE &typePtr,
 
 #ifdef LOGGING
             case ELEMENT_TYPE_INTERNAL :
+            case ELEMENT_TYPE_CMOD_INTERNAL :
+                typePtr += 1;
+                Reiterate = TRUE;
 #endif // LOGGING
                 return NULL;
 

src/coreclr/inc/corhdr.h

@@ -911,9 +911,10 @@ typedef enum CorElementType
 
     // This is for signatures generated internally (which will not be persisted in any way).
     ELEMENT_TYPE_INTERNAL       = 0x21,     // INTERNAL <typehandle>
+    ELEMENT_TYPE_CMOD_INTERNAL  = 0x22,     // CMOD_INTERNAL <required (1 byte: non-zero if required, 0 if optional)> <typehandle>
 
     // Note that this is the max of base type excluding modifiers
-    ELEMENT_TYPE_MAX            = 0x22,     // first invalid element type
+    ELEMENT_TYPE_MAX            = 0x23,     // first invalid element type
 
 
     ELEMENT_TYPE_MODIFIER       = 0x40,

src/coreclr/inc/corinfo.h

@@ -644,6 +644,7 @@ enum CorInfoTypeWithMod
 {
     CORINFO_TYPE_MASK            = 0x3F,        // lower 6 bits are type mask
     CORINFO_TYPE_MOD_PINNED      = 0x40,        // can be applied to CLASS, or BYREF to indicate pinned
+    CORINFO_TYPE_MOD_COPY_WITH_HELPER = 0x80    // can be applied to VALUECLASS to indicate 'needs helper to copy'
 };
 
 inline CorInfoType strip(CorInfoTypeWithMod val) {
@@ -3325,6 +3326,8 @@ class ICorDynamicInfo : public ICorStaticInfo
     // but for tailcalls, the contract is that JIT leaves the indirection cell in
     // a register during tailcall.
     virtual void updateEntryPointForTailCall(CORINFO_CONST_LOOKUP* entryPoint) = 0;
+
+    virtual CORINFO_METHOD_HANDLE getSpecialCopyHelper(CORINFO_CLASS_HANDLE type) = 0;
 };
 
 /**********************************************************************************/

src/coreclr/inc/cortypeinfo.h

@@ -54,3 +54,4 @@ TYPEINFO(ELEMENT_TYPE_MVAR,         NULL, NULL,                TARGET_POINTER_SI
 TYPEINFO(ELEMENT_TYPE_CMOD_REQD,    NULL, NULL,                0,                    TYPE_GC_NONE,   false,  false,  false,  false,  false) // 0x1f
 TYPEINFO(ELEMENT_TYPE_CMOD_OPT,     NULL, NULL,                0,                    TYPE_GC_NONE,   false,  false,  false,  false,  false) // 0x20
 TYPEINFO(ELEMENT_TYPE_INTERNAL,     NULL, NULL,                0,                    TYPE_GC_OTHER,  false,  false,  false,  false,  false) // 0x21
+TYPEINFO(ELEMENT_TYPE_CMOD_INTERNAL,NULL, NULL,                0,                    TYPE_GC_NONE,   false,  false,  false,  false,  false) // 0x22

src/coreclr/inc/formattype.cpp

@@ -694,6 +694,44 @@ PCCOR_SIGNATURE PrettyPrintType(
                 appendStr(out, sz);
                 break;
             }
+            case ELEMENT_TYPE_CMOD_INTERNAL :
+            {
+                // ELEMENT_TYPE_CMOD_INTERNAL <required> <TypeHandle>
+                bool required = *typePtr++ != 0;
+                _ASSERTE(sizeof(TypeHandle) == sizeof(void *));
+                TypeHandle typeHandle;
+                typePtr += CorSigUncompressPointer(typePtr, (void **)&typeHandle);
+
+                MethodTable *pMT = NULL;
+                if (typeHandle.IsTypeDesc())
+                {
+                    pMT = typeHandle.AsTypeDesc()->GetMethodTable();
+                    if (pMT)
+                    {
+                        PrettyPrintClass(out, pMT->GetCl(), pMT->GetMDImport());
+
+                        // It could be a "native version" of the managed type used in interop
+                        if (typeHandle.AsTypeDesc()->IsNativeValueType())
+                            appendStr(out, "_NativeValueType");
+                    }
+                    else
+                        appendStr(out, "(null)");
+                }
+                else
+                {
+                    pMT = typeHandle.AsMethodTable();
+                    if (pMT)
+                        PrettyPrintClass(out, pMT->GetCl(), pMT->GetMDImport());
+                    else
+                        appendStr(out, "(null)");
+                }
+
+                const char fmt[] = " mod%s(/* MT: %p */)";
+                char sz[Max64BitHexString + ARRAY_SIZE(fmt) + ARRAY_SIZE("req")];
+                sprintf_s(sz, ARRAY_SIZE(sz), fmt, required ? "req" : "opt", pMT);
+                appendStr(out, sz);
+                break;
+            }
 #endif
 
 

src/coreclr/inc/icorjitinfoimpl_generated.h

@@ -742,6 +742,9 @@ uint32_t getJitFlags(
           CORJIT_FLAGS* flags,
           uint32_t sizeInBytes) override;
 
+CORINFO_METHOD_HANDLE getSpecialCopyHelper(
+          CORINFO_CLASS_HANDLE type) override;
+
 /**********************************************************************************/
 // clang-format on
 /**********************************************************************************/

src/coreclr/inc/jiteeversionguid.h

@@ -43,11 +43,11 @@ typedef const GUID *LPCGUID;
 #define GUID_DEFINED
 #endif // !GUID_DEFINED
 
-constexpr GUID JITEEVersionIdentifier = { /* f43f9022-8795-4791-ba55-c450d76cfeb9 */
-    0xf43f9022,
-    0x8795,
-    0x4791,
-    {0xba, 0x55, 0xc4, 0x50, 0xd7, 0x6c, 0xfe, 0xb9}
+constexpr GUID JITEEVersionIdentifier = { /* 62865a69-7c84-4ba5-8636-a7dec55c05a7 */
+    0x62865a69,
+    0x7c84,
+    0x4ba5,
+    {0x86, 0x36, 0xa7, 0xde, 0xc5, 0x5c, 0x05, 0xa7}
   };
 
 //////////////////////////////////////////////////////////////////////////////////////////////////////////

src/coreclr/inc/sigparser.h

@@ -582,19 +582,32 @@ class SigParser
                 return hr;
 
             while ((ELEMENT_TYPE_CMOD_REQD == bElementType) ||
-                   (ELEMENT_TYPE_CMOD_OPT == bElementType))
+                   (ELEMENT_TYPE_CMOD_OPT == bElementType) ||
+                   (ELEMENT_TYPE_CMOD_INTERNAL == bElementType))
             {
                 sigTemp.SkipBytes(1);
+                if (ELEMENT_TYPE_CMOD_INTERNAL == bElementType)
+                {
+                    void * pMT;
+                    // If this custom modifier is required or optional
+                    uint8_t required;
+                    if (FAILED(hr = sigTemp.GetByte(&required)))
+                        return hr;
+
+                    if (FAILED(hr = sigTemp.GetPointer(&pMT)))
+                        return hr;
+                }
+                else
+                {
+                    mdToken token;
 
-                mdToken token;
-
-                hr = sigTemp.GetToken(&token);
+                    hr = sigTemp.GetToken(&token);
 
-                if (FAILED(hr))
-                    return hr;
+                    if (FAILED(hr))
+                        return hr;
+                }
 
-                hr = sigTemp.PeekByte(&bElementType);
-                if (FAILED(hr))
+                if (FAILED(hr = sigTemp.PeekByte(&bElementType)))
                     return hr;
             }
 
@@ -643,19 +656,31 @@ class SigParser
             while (ELEMENT_TYPE_CMOD_REQD == bElementType ||
                    ELEMENT_TYPE_CMOD_OPT == bElementType ||
                    ELEMENT_TYPE_MODIFIER == bElementType ||
-                   ELEMENT_TYPE_PINNED == bElementType)
+                   ELEMENT_TYPE_PINNED == bElementType ||
+                   ELEMENT_TYPE_CMOD_INTERNAL == bElementType)
             {
                 sigTemp.SkipBytes(1);
+                if (ELEMENT_TYPE_CMOD_INTERNAL == bElementType)
+                {
+                    void * pMT;
+                    uint8_t required;
+                    if (FAILED(hr = sigTemp.GetByte(&required)))
+                        return hr;
+
+                    if (FAILED(hr = sigTemp.GetPointer(&pMT)))
+                        return hr;
+                }
+                else
+                {
+                    mdToken token;
 
-                mdToken token;
-
-                hr = sigTemp.GetToken(&token);
+                    hr = sigTemp.GetToken(&token);
 
-                if (FAILED(hr))
-                    return hr;
+                    if (FAILED(hr))
+                        return hr;
+                }
 
-                hr = sigTemp.PeekByte(&bElementType);
-                if (FAILED(hr))
+                if (FAILED(hr = sigTemp.PeekByte(&bElementType)))
                     return hr;
             }
 

src/coreclr/jit/ICorJitInfo_names_generated.h

@@ -180,5 +180,6 @@ DEF_CLR_API(recordRelocation)
 DEF_CLR_API(getRelocTypeHint)
 DEF_CLR_API(getExpectedTargetArchitecture)
 DEF_CLR_API(getJitFlags)
+DEF_CLR_API(getSpecialCopyHelper)
 
 #undef DEF_CLR_API

src/coreclr/jit/ICorJitInfo_wrapper_generated.hpp

@@ -1742,6 +1742,15 @@ uint32_t WrapICorJitInfo::getJitFlags(
     return temp;
 }
 
+CORINFO_METHOD_HANDLE WrapICorJitInfo::getSpecialCopyHelper(
+          CORINFO_CLASS_HANDLE type)
+{
+    API_ENTER(getSpecialCopyHelper);
+    CORINFO_METHOD_HANDLE temp = wrapHnd->getSpecialCopyHelper(type);
+    API_LEAVE(getSpecialCopyHelper);
+    return temp;
+}
+
 /**********************************************************************************/
 // clang-format on
 /**********************************************************************************/

src/coreclr/jit/compiler.cpp

@@ -1989,6 +1989,10 @@ void Compiler::compInit(ArenaAllocator*       pAlloc,
     m_fpStructLoweringCache = nullptr;
 #endif
 
+#if defined(TARGET_X86) && defined(FEATURE_IJW)
+    m_specialCopyArgs = nullptr;
+#endif
+
     // check that HelperCallProperties are initialized
 
     assert(s_helperCallProperties.IsPure(CORINFO_HELP_GET_GCSTATIC_BASE));

src/coreclr/jit/compiler.h

@@ -5703,6 +5703,36 @@ class Compiler
     const CORINFO_SWIFT_LOWERING* GetSwiftLowering(CORINFO_CLASS_HANDLE clsHnd);
 #endif
 
+#if defined(TARGET_X86) && defined(FEATURE_IJW)
+    bool* m_specialCopyArgs;
+    bool recordArgRequiresSpecialCopy(unsigned argNum)
+    {
+        if (argNum >= info.compArgsCount)
+        {
+            return false;
+        }
+
+        if (m_specialCopyArgs == nullptr)
+        {
+            m_specialCopyArgs = new (getAllocator()) bool[info.compArgsCount];
+            memset(m_specialCopyArgs, 0, info.compArgsCount * sizeof(bool));
+        }
+
+        m_specialCopyArgs[argNum] = true;
+        return true;
+    }
+
+    bool argRequiresSpecialCopy(unsigned argNum)
+    {
+        return argNum < info.compArgsCount && m_specialCopyArgs != nullptr && m_specialCopyArgs[argNum];
+    }
+
+    bool compHasSpecialCopyArgs()
+    {
+        return m_specialCopyArgs != nullptr;
+    }
+#endif
+
     void optRecordLoopMemoryDependence(GenTree* tree, BasicBlock* block, ValueNum memoryVN);
     void optCopyLoopMemoryDependence(GenTree* fromTree, GenTree* toTree);
 

src/coreclr/jit/gentree.cpp

@@ -16599,6 +16599,7 @@ GenTree* Compiler::gtNewTempStore(
         valTyp      = lvaGetRealType(val->AsLclVar()->GetLclNum());
         val->gtType = valTyp;
     }
+
     var_types dstTyp = varDsc->TypeGet();
 
     /* If the variable's lvType is not yet set then set it here */