Virtual stub indirect call profiling

src/coreclr/jit/compiler.h

@@ -11888,7 +11888,7 @@ class GenTreeVisitor
 
                 if (call->gtCallType == CT_INDIRECT)
                 {
-                    if (call->gtCallCookie != nullptr)
+                    if (!call->IsVirtualStub() && (call->gtCallCookie != nullptr))
                     {
                         result = WalkTree(&call->gtCallCookie, call);
                         if (result == fgWalkResult::WALK_ABORT)

src/coreclr/jit/compiler.hpp

@@ -4683,7 +4683,8 @@ void GenTree::VisitOperands(TVisitor visitor)
 
             if (call->gtCallType == CT_INDIRECT)
             {
-                if ((call->gtCallCookie != nullptr) && (visitor(call->gtCallCookie) == VisitResult::Abort))
+                if ((call->gtCallCookie != nullptr) && !call->IsVirtualStub() &&
+                    (visitor(call->gtCallCookie) == VisitResult::Abort))
                 {
                     return;
                 }

src/coreclr/jit/gentree.cpp

@@ -5977,7 +5977,9 @@ unsigned Compiler::gtSetEvalOrder(GenTree* tree)
             if (call->gtCallType == CT_INDIRECT)
             {
                 // pinvoke-calli cookie is a constant, or constant indirection
-                assert(call->gtCallCookie == nullptr || call->gtCallCookie->OperIs(GT_CNS_INT, GT_IND));
+                // or a non-tree if this is a managed call.
+                assert(call->IsVirtualStub() || (call->gtCallCookie == nullptr) ||
+                       call->gtCallCookie->OperIs(GT_CNS_INT, GT_IND));
 
                 GenTree* indirect = call->gtCallAddr;
 
@@ -6725,7 +6727,7 @@ bool GenTree::TryGetUse(GenTree* operand, GenTree*** pUse)
             }
             if (call->gtCallType == CT_INDIRECT)
             {
-                if (operand == call->gtCallCookie)
+                if (!call->IsVirtualStub() && (operand == call->gtCallCookie))
                 {
                     *pUse = &call->gtCallCookie;
                     return true;
@@ -9899,16 +9901,23 @@ GenTreeCall* Compiler::gtCloneExprCallHelper(GenTreeCall* tree)
     /* Copy the union */
     if (tree->gtCallType == CT_INDIRECT)
     {
-        copy->gtCallCookie = tree->gtCallCookie ? gtCloneExpr(tree->gtCallCookie) : nullptr;
-        copy->gtCallAddr   = tree->gtCallAddr ? gtCloneExpr(tree->gtCallAddr) : nullptr;
+        if (tree->IsVirtualStub())
+        {
+            copy->gtCallCookie = tree->gtCallCookie;
+        }
+        else
+        {
+            copy->gtCallCookie = tree->gtCallCookie ? gtCloneExpr(tree->gtCallCookie) : nullptr;
+        }
+        copy->gtCallAddr = tree->gtCallAddr ? gtCloneExpr(tree->gtCallAddr) : nullptr;
     }
     else
     {
         copy->gtCallMethHnd         = tree->gtCallMethHnd;
         copy->gtInlineCandidateInfo = tree->gtInlineCandidateInfo;
-        copy->gtInlineInfoCount     = tree->gtInlineInfoCount;
     }
 
+    copy->gtInlineInfoCount          = tree->gtInlineInfoCount;
     copy->gtLateDevirtualizationInfo = tree->gtLateDevirtualizationInfo;
 
     copy->gtCallType   = tree->gtCallType;
@@ -10641,7 +10650,7 @@ void GenTreeUseEdgeIterator::AdvanceCall()
             assert(call->gtCallType == CT_INDIRECT);
 
             m_advance = &GenTreeUseEdgeIterator::AdvanceCall<CALL_ADDRESS>;
-            if (call->gtCallCookie != nullptr)
+            if (!call->IsVirtualStub() && (call->gtCallCookie != nullptr))
             {
                 m_edge = &call->gtCallCookie;
                 return;
@@ -10964,6 +10973,11 @@ void Compiler::gtDispNodeName(GenTree* tree)
         }
         else if (tree->AsCall()->gtCallType == CT_INDIRECT)
         {
+            if (tree->AsCall()->IsVirtual())
+            {
+                callType = "CALLV";
+            }
+
             ctType = " ind";
         }
         else

src/coreclr/jit/importer.cpp

@@ -6935,8 +6935,20 @@ void Compiler::impImportBlockCode(BasicBlock* block)
                     {
                         JITDUMP(".... checking for GDV of IEnumerable<T>...\n");
 
-                        GenTreeCall* const   call = op1->AsRetExpr()->gtInlineCandidate;
-                        NamedIntrinsic const ni   = lookupNamedIntrinsic(call->gtCallMethHnd);
+                        GenTreeCall* const call = op1->AsRetExpr()->gtInlineCandidate;
+                        NamedIntrinsic     ni   = NI_Illegal;
+
+                        // TODO -- handle CT_INDIRECT virtuals here too
+                        // but we don't have the right method handle
+                        //
+                        if (call->gtCallType == CT_USER_FUNC)
+                        {
+                            ni = lookupNamedIntrinsic(call->gtCallMethHnd);
+                        }
+                        else if (call->IsGuardedDevirtualizationCandidate())
+                        {
+                            JITDUMP("No GDV IEnumerable<T> check for [%06u]\n", dspTreeID(call));
+                        }
 
                         if (ni == NI_System_Collections_Generic_IEnumerable_GetEnumerator)
                         {

src/coreclr/jit/importercalls.cpp

@@ -7276,7 +7276,8 @@ void Compiler::considerGuardedDevirtualization(GenTreeCall*            call,
 
             if (!canResolve)
             {
-                JITDUMP("Can't figure out which method would be invoked, sorry\n");
+                JITDUMP("Can't figure out which method would be invoked, sorry. [%s]\n",
+                        devirtualizationDetailToString(dvInfo.detail));
 
                 // Continue checking other candidates, maybe some of them will succeed.
                 break;
@@ -7695,20 +7696,28 @@ void Compiler::impMarkInlineCandidateHelper(GenTreeCall*           call,
         }
     }
 
-    /* Ignore helper calls */
-
+    // Ignore helper calls
+    //
     if (call->IsHelperCall())
     {
         assert(!call->IsGuardedDevirtualizationCandidate());
         inlineResult->NoteFatal(InlineObservation::CALLSITE_IS_CALL_TO_HELPER);
         return;
     }
 
-    /* Ignore indirect calls */
+    // Ignore indirect calls, unless they are indirect virtual stub calls with profile info.
+    //
     if (call->gtCallType == CT_INDIRECT)
     {
-        inlineResult->NoteFatal(InlineObservation::CALLSITE_IS_NOT_DIRECT_MANAGED);
-        return;
+        if (!call->IsGuardedDevirtualizationCandidate())
+        {
+            inlineResult->NoteFatal(InlineObservation::CALLSITE_IS_NOT_DIRECT_MANAGED);
+            return;
+        }
+        else
+        {
+            assert(call->IsVirtualStub());
+        }
     }
 
     // The inliner gets confused when the unmanaged convention reverses arg order (like x86).
@@ -8924,11 +8933,6 @@ bool Compiler::impConsiderCallProbe(GenTreeCall* call, IL_OFFSET ilOffset)
 //
 Compiler::GDVProbeType Compiler::compClassifyGDVProbeType(GenTreeCall* call)
 {
-    if (call->gtCallType == CT_INDIRECT)
-    {
-        return GDVProbeType::None;
-    }
-
     if (!opts.jitFlags->IsSet(JitFlags::JIT_FLAG_BBINSTR) || IsAot())
     {
         return GDVProbeType::None;

src/coreclr/jit/inline.cpp

@@ -1344,9 +1344,7 @@ InlineContext* InlineStrategy::NewContext(InlineContext* parentContext, Statemen
     // which becomes a single statement where the IL location points to the
     // ldarg instruction.
     context->m_Location = stmt->GetDebugInfo().GetLocation();
-
-    assert(call->gtCallType == CT_USER_FUNC);
-    context->m_Callee = call->gtCallMethHnd;
+    context->m_Callee   = call->gtCallMethHnd;
 
 #if defined(DEBUG)
     context->m_Devirtualized = call->IsDevirtualized();

src/coreclr/jit/morph.cpp

@@ -1773,7 +1773,7 @@ void CallArgs::AddFinalArgsAndDetermineABIInfo(Compiler* comp, GenTreeCall* call
             // add as a non-standard arg.
         }
     }
-    else if (call->gtCallType == CT_INDIRECT && (call->gtCallCookie != nullptr))
+    else if ((call->gtCallType == CT_INDIRECT) && !call->IsVirtualStub() && (call->gtCallCookie != nullptr))
     {
         assert(!call->IsUnmanaged());
 

src/coreclr/vm/jitinterface.cpp

@@ -8638,7 +8638,7 @@ bool CEEInfo::resolveVirtualMethodHelper(CORINFO_DEVIRTUALIZATION_INFO * info)
                 return false;
             }
         }
-        else if (!pObjMT->CanCastToInterface(pBaseMT))
+        else if (!pBaseMT->IsSharedByGenericInstantiations() && !pObjMT->CanCastToInterface(pBaseMT))
         {
             info->detail = CORINFO_DEVIRTUALIZATION_FAILED_CAST;
             return false;
@@ -8648,32 +8648,49 @@ bool CEEInfo::resolveVirtualMethodHelper(CORINFO_DEVIRTUALIZATION_INFO * info)
         // safely devirtualize.
         if (info->context != nullptr)
         {
-            // If the derived class is a shared class, make sure the
-            // owner class is too.
-            if (pObjMT->IsSharedByGenericInstantiations())
+            MethodTable* interfaceMT = nullptr;
+
+            if (pObjMT->IsSharedByGenericInstantiations() || pBaseMT->IsSharedByGenericInstantiations())
             {
                 MethodTable* pCanonBaseMT = pBaseMT->GetCanonicalMethodTable();
-
+                
                 // Check to see if the derived class implements multiple variants of a matching interface.
                 // If so, we cannot predict exactly which implementation is in use here.
                 MethodTable::InterfaceMapIterator it = pObjMT->IterateInterfaceMap();
                 int canonicallyMatchingInterfacesFound = 0;
+                MethodTable* interfaceMT = nullptr;
                 while (it.Next())
                 {
-                    if (it.GetInterface(pObjMT)->GetCanonicalMethodTable() == pCanonBaseMT)
+                    MethodTable* mt = it.GetInterface(pObjMT);
+                    if (mt->GetCanonicalMethodTable() == pCanonBaseMT)
                     {
+                        interfaceMT = mt;
                         canonicallyMatchingInterfacesFound++;
+
                         if (canonicallyMatchingInterfacesFound > 1)
                         {
-                            // Multiple canonically identical interfaces found when attempting to devirtualize an inexact interface dispatch
+                            // Multiple canonically identical interfaces found.
+                            //
                             info->detail = CORINFO_DEVIRTUALIZATION_MULTIPLE_IMPL;
                             return false;
                         }
                     }
                 }
-            }
+
+                if (canonicallyMatchingInterfacesFound == 0)
+                {
+                    // The object doesn't implement the interface...
+                    //
+                    info->detail = CORINFO_DEVIRTUALIZATION_FAILED_CAST;
+                    return false;
+                }
 
-            pDevirtMD = pObjMT->GetMethodDescForInterfaceMethod(TypeHandle(pBaseMT), pBaseMD, FALSE /* throwOnConflict */);
+                pDevirtMD = pObjMT->GetMethodDescForInterfaceMethod(TypeHandle(interfaceMT), pBaseMD, FALSE /* throwOnConflict */);
+            }
+            else
+            {
+                pDevirtMD = pObjMT->GetMethodDescForInterfaceMethod(TypeHandle(pBaseMT), pBaseMD, FALSE /* throwOnConflict */);
+            }
         }
         else if (!pBaseMD->HasClassOrMethodInstantiation())
         {