Remove AggressiveOpt from CastHelpers.LdelemaRef/StelemRef

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

@@ -411,7 +411,6 @@ internal struct ArrayElement
         [DebuggerHidden]
         [StackTraceHidden]
         [DebuggerStepThrough]
-        [MethodImpl(MethodImplOptions.AggressiveOptimization)]
         private static ref object? LdelemaRef(Array array, nint index, void* type)
         {
             // this will throw appropriate exceptions if array is null or access is out of range.
@@ -427,7 +426,6 @@ internal struct ArrayElement
         [DebuggerHidden]
         [StackTraceHidden]
         [DebuggerStepThrough]
-        [MethodImpl(MethodImplOptions.AggressiveOptimization)]
         private static void StelemRef(Array array, nint index, object? obj)
         {
             // this will throw appropriate exceptions if array is null or access is out of range.

src/coreclr/vm/ecall.cpp

@@ -137,27 +137,12 @@ void ECall::PopulateManagedCastHelpers()
     pDest = pMD->GetMultiCallableAddrOfCode();
     SetJitHelperFunction(CORINFO_HELP_UNBOX, pDest);
 
-    // Array element accessors are more perf sensitive than other managed helpers and indirection
-    // costs introduced by PreStub could be noticeable (7% to 30% depending on platform).
-    // Other helpers are either more complex, less common, or have their trivial case inlined by the JIT,
-    // so indirection is not as big concern.
-    // We JIT-compile the following helpers eagerly here to avoid indirection costs.
-
-    //TODO: revise if this specialcasing is still needed when crossgen supports tailcall optimizations
-    //      see: https://github.com/dotnet/runtime/issues/5857
-
     pMD = CoreLibBinder::GetMethod((BinderMethodID)(METHOD__CASTHELPERS__STELEMREF));
-    pMD->DoPrestub(NULL);
-    // This helper is marked AggressiveOptimization and its native code is in its final form.
-    // Get the code directly to avoid PreStub indirection.
-    pDest = pMD->GetNativeCode();
+    pDest = pMD->GetMultiCallableAddrOfCode();
     SetJitHelperFunction(CORINFO_HELP_ARRADDR_ST, pDest);
 
     pMD = CoreLibBinder::GetMethod((BinderMethodID)(METHOD__CASTHELPERS__LDELEMAREF));
-    pMD->DoPrestub(NULL);
-    // This helper is marked AggressiveOptimization and its native code is in its final form.
-    // Get the code directly to avoid PreStub indirection.
-    pDest = pMD->GetNativeCode();
+    pDest = pMD->GetMultiCallableAddrOfCode();
     SetJitHelperFunction(CORINFO_HELP_LDELEMA_REF, pDest);
 }
 

src/coreclr/vm/jitinterface.cpp

@@ -10614,6 +10614,14 @@ void* CEEJitInfo::getHelperFtn(CorInfoHelpFunc    ftnNum,         /* IN  */
         }
 #endif
 
+        // Check if we already have a cached address of the final target
+        static LPVOID hlpFinalTierAddrTable[DYNAMIC_CORINFO_HELP_COUNT] = {};
+        LPVOID finalTierAddr = hlpFinalTierAddrTable[dynamicFtnNum];
+        if (finalTierAddr != NULL)
+        {
+            return finalTierAddr;
+        }
+
         if (dynamicFtnNum == DYNAMIC_CORINFO_HELP_ISINSTANCEOFINTERFACE ||
             dynamicFtnNum == DYNAMIC_CORINFO_HELP_ISINSTANCEOFANY ||
             dynamicFtnNum == DYNAMIC_CORINFO_HELP_ISINSTANCEOFARRAY ||
@@ -10623,10 +10631,37 @@ void* CEEJitInfo::getHelperFtn(CorInfoHelpFunc    ftnNum,         /* IN  */
             dynamicFtnNum == DYNAMIC_CORINFO_HELP_CHKCASTINTERFACE ||
             dynamicFtnNum == DYNAMIC_CORINFO_HELP_CHKCASTCLASS ||
             dynamicFtnNum == DYNAMIC_CORINFO_HELP_CHKCASTCLASS_SPECIAL ||
-            dynamicFtnNum == DYNAMIC_CORINFO_HELP_UNBOX)
+            dynamicFtnNum == DYNAMIC_CORINFO_HELP_UNBOX ||
+            dynamicFtnNum == DYNAMIC_CORINFO_HELP_ARRADDR_ST ||
+            dynamicFtnNum == DYNAMIC_CORINFO_HELP_LDELEMA_REF)
         {
             Precode* pPrecode = Precode::GetPrecodeFromEntryPoint((PCODE)hlpDynamicFuncTable[dynamicFtnNum].pfnHelper);
             _ASSERTE(pPrecode->GetType() == PRECODE_FIXUP);
+
+            MethodDesc* helperMD = pPrecode->GetMethodDesc();
+            _ASSERT(helperMD != nullptr);
+
+            // Check if the target MethodDesc is already jitted to its final Tier
+            // so we no longer need to use indirections and can emit a direct call instead.
+            NativeCodeVersion::OptimizationTier tier;
+
+            {
+                CodeVersionManager::LockHolder codeVersioningLockHolder;
+                NativeCodeVersion activeCodeVersion = helperMD->GetCodeVersionManager()->GetActiveILCodeVersion(helperMD)
+                    .GetActiveNativeCodeVersion(helperMD);
+                tier = activeCodeVersion.GetOptimizationTier();
+            }
+
+            if (tier == NativeCodeVersion::OptimizationTier::OptimizationTier1 ||
+                tier == NativeCodeVersion::OptimizationTier::OptimizationTierOptimized)
+            {
+                finalTierAddr = (LPVOID)GetEEFuncEntryPoint(hlpDynamicFuncTable[dynamicFtnNum].pfnHelper);
+                _ASSERT(finalTierAddr != NULL);
+                // Cache it for future uses to avoid taking the lock again.
+                hlpFinalTierAddrTable[dynamicFtnNum] = finalTierAddr;
+                return finalTierAddr;
+            }
+
             *ppIndirection = ((FixupPrecode*)pPrecode)->GetTargetSlot();
             return NULL;
         }