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JIT: Add guarded devirtualization support for generic virtual methods #132361

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379885a
Profile class and method for GDV
hez2010 Aug 15, 2026
199c406
Merge branch 'main' into gvm-gdv
hez2010 Aug 15, 2026
87f604b
Fix format
hez2010 Aug 15, 2026
7390c7d
Format config as well
hez2010 Aug 15, 2026
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2 changes: 2 additions & 0 deletions src/coreclr/inc/corinfo.h
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Expand Up @@ -577,6 +577,8 @@ enum CorInfoHelpFunc
CORINFO_HELP_DELEGATEPROFILE64, // Update 64-bit method profile for a delegate call site
CORINFO_HELP_VTABLEPROFILE32, // Update 32-bit method profile for a vtable call site
CORINFO_HELP_VTABLEPROFILE64, // Update 64-bit method profile for a vtable call site
CORINFO_HELP_GENERICVIRTUALPROFILE32, // Update 32-bit method profile for a generic virtual call site
CORINFO_HELP_GENERICVIRTUALPROFILE64, // Update 64-bit method profile for a generic virtual call site
CORINFO_HELP_COUNTPROFILE32, // Update 32-bit block or edge count profile
CORINFO_HELP_COUNTPROFILE64, // Update 64-bit block or edge count profile
CORINFO_HELP_VALUEPROFILE32, // Update 32-bit value profile
Expand Down
10 changes: 5 additions & 5 deletions src/coreclr/inc/jiteeversionguid.h
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Expand Up @@ -37,11 +37,11 @@

#include <minipal/guid.h>

constexpr GUID JITEEVersionIdentifier = { /* 0d18a7df-af1f-4481-a72f-aa6cf8aa0a65 */
0x0d18a7df,
0xaf1f,
0x4481,
{0xa7, 0x2f, 0xaa, 0x6c, 0xf8, 0xaa, 0x0a, 0x65}
constexpr GUID JITEEVersionIdentifier = { /* c31fbc28-2e59-4770-b836-61c690978dc2 */
0xc31fbc28,
0x2e59,
0x4770,
{0xb8, 0x36, 0x61, 0xc6, 0x90, 0x97, 0x8d, 0xc2}
};

#endif // JIT_EE_VERSIONING_GUID_H
4 changes: 4 additions & 0 deletions src/coreclr/inc/jithelpers.h
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Expand Up @@ -336,6 +336,8 @@
JITHELPER(CORINFO_HELP_DELEGATEPROFILE64, JIT_DelegateProfile64, METHOD__NIL)
JITHELPER(CORINFO_HELP_VTABLEPROFILE32, JIT_VTableProfile32, METHOD__NIL)
JITHELPER(CORINFO_HELP_VTABLEPROFILE64, JIT_VTableProfile64, METHOD__NIL)
JITHELPER(CORINFO_HELP_GENERICVIRTUALPROFILE32, JIT_GenericVirtualProfile32, METHOD__NIL)
JITHELPER(CORINFO_HELP_GENERICVIRTUALPROFILE64, JIT_GenericVirtualProfile64, METHOD__NIL)
JITHELPER(CORINFO_HELP_COUNTPROFILE32, JIT_CountProfile32, METHOD__NIL)
JITHELPER(CORINFO_HELP_COUNTPROFILE64, JIT_CountProfile64, METHOD__NIL)
JITHELPER(CORINFO_HELP_VALUEPROFILE32, JIT_ValueProfile32, METHOD__NIL)
Expand All @@ -347,6 +349,8 @@
JITHELPER(CORINFO_HELP_DELEGATEPROFILE64, NULL, METHOD__NIL)
JITHELPER(CORINFO_HELP_VTABLEPROFILE32, NULL, METHOD__NIL)
JITHELPER(CORINFO_HELP_VTABLEPROFILE64, NULL, METHOD__NIL)
JITHELPER(CORINFO_HELP_GENERICVIRTUALPROFILE32, NULL, METHOD__NIL)
JITHELPER(CORINFO_HELP_GENERICVIRTUALPROFILE64, NULL, METHOD__NIL)
JITHELPER(CORINFO_HELP_COUNTPROFILE32, NULL, METHOD__NIL)
JITHELPER(CORINFO_HELP_COUNTPROFILE64, NULL, METHOD__NIL)
JITHELPER(CORINFO_HELP_VALUEPROFILE32, NULL, METHOD__NIL)
Expand Down
85 changes: 62 additions & 23 deletions src/coreclr/jit/fgprofile.cpp
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Expand Up @@ -1968,7 +1968,9 @@ class BuildHandleHistogramProbeSchemaGen
ICorJitInfo::PgoInstrumentationSchema schemaElem = {};
schemaElem.Count = 1;
schemaElem.Other = isTypeHistogram ? ICorJitInfo::HandleHistogram32::CLASS_FLAG : 0;
if (call->IsVirtualStub())
if (call->IsVirtualStub() ||
(call->IsGenericVirtual(compiler) &&
((call->gtControlExpr->AsCall()->gtCallMoreFlags & GTF_CALL_M_LDVIRTFTN_INTERFACE) != 0)))
{
schemaElem.Other |= ICorJitInfo::HandleHistogram32::INTERFACE_FLAG;
}
Expand Down Expand Up @@ -2115,32 +2117,68 @@ class HandleHistogramProbeInserter

if (methodHistogram != nullptr)
{
GenTree* const tmpNode = compiler->gtNewLclvNode(tmpNum, TYP_REF);
GenTree* const methodProfileNode = compiler->gtNewIconNode((ssize_t)methodHistogram, TYP_I_IMPL);

GenTree* methodProfileCallNode;
if (call->IsDelegateInvoke())
if (call->IsGenericVirtual(compiler))
{
methodProfileCallNode = compiler->gtNewHelperCallNode(is32 ? CORINFO_HELP_DELEGATEPROFILE32
: CORINFO_HELP_DELEGATEPROFILE64,
TYP_VOID, tmpNode, methodProfileNode);
GenTreeCall* const lookupCall = call->gtControlExpr->AsCall();
assert(lookupCall->IsHelperCall(CORINFO_HELP_VIRTUAL_FUNC_PTR));
assert(!lookupCall->gtArgs.AreArgsComplete());

CallArg* const methodHandleArg = lookupCall->gtArgs.FindWellKnownArg(WellKnownArg::RuntimeMethodHandle);
assert(methodHandleArg != nullptr);
assert(methodHandleArg->GetEarlyNode()->TypeIs(TYP_I_IMPL));

// Spill the exact instantiated MethodDesc so the profile probe and dispatch lookup
// consume the same value without evaluating the method handle expression twice.
unsigned const methodTmpNum =
compiler->lvaGrabTemp(true DEBUGARG("generic virtual method profile tmp"));
compiler->lvaTable[methodTmpNum].lvType = TYP_I_IMPL;

GenTree* const storeNode =
compiler->gtNewStoreLclVarNode(methodTmpNum, methodHandleArg->GetEarlyNode());
GenTree* const methodHandleNode = compiler->gtNewLclvNode(methodTmpNum, TYP_I_IMPL);
GenTree* const methodProfileNode = compiler->gtNewIconNode((ssize_t)methodHistogram, TYP_I_IMPL);
GenTree* const profileCallNode =
compiler->gtNewHelperCallNode(is32 ? CORINFO_HELP_GENERICVIRTUALPROFILE32
: CORINFO_HELP_GENERICVIRTUALPROFILE64,
TYP_VOID, methodHandleNode, methodProfileNode);
GenTree* const methodTmpNode = compiler->gtNewLclvNode(methodTmpNum, TYP_I_IMPL);
GenTree* const profileCommaNode =
compiler->gtNewOperNode(GT_COMMA, TYP_I_IMPL, profileCallNode, methodTmpNode);
GenTree* const storeCommaNode =
compiler->gtNewOperNode(GT_COMMA, TYP_I_IMPL, storeNode, profileCommaNode);

methodHandleArg->SetEarlyNode(storeCommaNode);
}
else
{
assert(call->IsVirtualVtable());
GenTree* const baseMethodNode = compiler->gtNewIconEmbMethHndNode(call->gtCallMethHnd);
methodProfileCallNode =
compiler->gtNewHelperCallNode(is32 ? CORINFO_HELP_VTABLEPROFILE32 : CORINFO_HELP_VTABLEPROFILE64,
TYP_VOID, tmpNode, baseMethodNode, methodProfileNode);
}
GenTree* const tmpNode = compiler->gtNewLclvNode(tmpNum, TYP_REF);
GenTree* const methodProfileNode = compiler->gtNewIconNode((ssize_t)methodHistogram, TYP_I_IMPL);

if (helperCallNode == nullptr)
{
helperCallNode = methodProfileCallNode;
}
else
{
helperCallNode = compiler->gtNewOperNode(GT_COMMA, TYP_REF, helperCallNode, methodProfileCallNode);
GenTree* methodProfileCallNode;
if (call->IsDelegateInvoke())
{
methodProfileCallNode = compiler->gtNewHelperCallNode(is32 ? CORINFO_HELP_DELEGATEPROFILE32
: CORINFO_HELP_DELEGATEPROFILE64,
TYP_VOID, tmpNode, methodProfileNode);
}
else
{
assert(call->IsVirtualVtable());
GenTree* const baseMethodNode = compiler->gtNewIconEmbMethHndNode(call->gtCallMethHnd);
methodProfileCallNode =
compiler->gtNewHelperCallNode(is32 ? CORINFO_HELP_VTABLEPROFILE32
: CORINFO_HELP_VTABLEPROFILE64,
TYP_VOID, tmpNode, baseMethodNode, methodProfileNode);
}

if (helperCallNode == nullptr)
{
helperCallNode = methodProfileCallNode;
}
else
{
helperCallNode = compiler->gtNewOperNode(GT_COMMA, TYP_REF, helperCallNode, methodProfileCallNode);
}
}
}

Expand Down Expand Up @@ -2599,7 +2637,8 @@ PhaseStatus Compiler::fgPrepareToInstrumentMethod()
const bool useClassProfiles = (JitConfig.JitClassProfiling() > 0);
const bool useDelegateProfiles = (JitConfig.JitDelegateProfiling() > 0);
const bool useVTableProfiles = (JitConfig.JitVTableProfiling() > 0);
if (!prejit && (useClassProfiles || useDelegateProfiles || useVTableProfiles))
const bool useGvmProfiles = (JitConfig.JitGenericVirtualProfiling() > 0);
if (!prejit && (useClassProfiles || useDelegateProfiles || useVTableProfiles || useGvmProfiles))
{
fgHistogramInstrumentor = new (this, CMK_Pgo) HandleHistogramProbeInstrumentor(this);
}
Expand Down
36 changes: 17 additions & 19 deletions src/coreclr/jit/importercalls.cpp
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Expand Up @@ -8200,7 +8200,7 @@ void Compiler::pickGDV(GenTreeCall* call,
const int maxLikelyClasses = MAX_GDV_TYPE_CHECKS;
LikelyClassMethodRecord likelyClasses[maxLikelyClasses];
unsigned numberOfClasses = 0;
if (call->IsVirtualStub() || call->IsVirtualVtable() || call->IsHelperCall())
if (call->IsVirtualStub() || call->IsVirtualVtable() || call->IsHelperCall() || call->IsGenericVirtual(this))
{
numberOfClasses = getLikelyClasses(likelyClasses, maxLikelyClasses, pgoInfo.PgoSchema, pgoInfo.PgoSchemaCount,
pgoInfo.PgoData, ilOffset);
Expand All @@ -8217,7 +8217,7 @@ void Compiler::pickGDV(GenTreeCall* call,
// impDevirtualizeCall and what happens in
// GuardedDevirtualizationTransformer::CreateThen for method GDV.
//
if (!IsAot() && (call->IsVirtualVtable() || call->IsDelegateInvoke()))
if (!IsAot() && (call->IsVirtualVtable() || call->IsDelegateInvoke() || call->IsGenericVirtual(this)))
{
assert(!call->IsHelperCall());
numberOfMethods = getLikelyMethods(likelyMethods, maxLikelyMethods, pgoInfo.PgoSchema, pgoInfo.PgoSchemaCount,
Expand Down Expand Up @@ -8295,8 +8295,9 @@ void Compiler::pickGDV(GenTreeCall* call,

if ((verbose || JitConfig.EnableExtraSuperPmiQueries()) && (numberOfMethods > 0))
{
assert(call->gtCallType == CT_USER_FUNC);
const char* baseMethName = eeGetMethodFullName(call->gtCallMethHnd);
assert(call->gtCallType == CT_USER_FUNC || call->IsGenericVirtual(this));
const char* baseMethName =
call->IsGenericVirtual(this) ? "<generic virtual>" : eeGetMethodFullName(call->gtCallMethHnd);
JITDUMP("Likely methods for call [%06u] to method %s\n", dspTreeID(call), baseMethName);

for (UINT32 i = 0; i < numberOfMethods; i++)
Expand Down Expand Up @@ -8663,12 +8664,6 @@ void Compiler::considerGuardedDevirtualization(GenTreeCall* call,
{
JITDUMP("Considering guarded devirtualization at IL offset %u (0x%x)\n", ilOffset, ilOffset);

if (call->IsGenericVirtual(this))
{
JITDUMP("Generic virtual methods are not supported by guarded devirtualization, sorry.\n");
return;
}

bool hasPgoData = true;

CORINFO_CLASS_HANDLE likelyClasses[MAX_GDV_TYPE_CHECKS] = {};
Expand Down Expand Up @@ -8802,6 +8797,7 @@ void Compiler::considerGuardedDevirtualization(GenTreeCall* call,
{
CORINFO_CLASS_HANDLE likelyClass = likelyClasses[candidateId];
CORINFO_METHOD_HANDLE likelyMethod = likelyMethods[candidateId];
CORINFO_METHOD_HANDLE originalMethod = call->IsGenericVirtual(this) ? likelyMethod : baseMethod;
unsigned likelihood = likelihoods[candidateId];
const CORINFO_LOOKUP* pInstParamLookup = nullptr;
CORINFO_RESOLVED_TOKEN* pResolvedToken = nullptr;
Expand All @@ -8828,7 +8824,7 @@ void Compiler::considerGuardedDevirtualization(GenTreeCall* call,

// Figure out which method will be called.
//
dvInfo.virtualMethod = baseMethod;
dvInfo.virtualMethod = originalMethod;
dvInfo.objClass = likelyClass;
dvInfo.context = originalContext;
dvInfo.pResolvedTokenVirtualMethod = nullptr;
Expand Down Expand Up @@ -8926,7 +8922,7 @@ void Compiler::considerGuardedDevirtualization(GenTreeCall* call,
// Add this as a potential candidate.
//
addGuardedDevirtualizationCandidate(call, likelyMethod, likelyClass, likelyContext, likelyMethodAttribs,
likelyClassAttribs, likelihood, pInstParamLookup, baseMethod,
likelyClassAttribs, likelihood, pInstParamLookup, originalMethod,
pResolvedToken, pUnboxedResolvedToken);
}
}
Expand All @@ -8953,7 +8949,7 @@ void Compiler::considerGuardedDevirtualization(GenTreeCall* call,
// classAttr - attributes of the class
// likelihood - odds that this class is the class seen at runtime
// instParamLookup - lookup to use if the target signature requires an instantiation argument
// originalMethodHandle - method handle of base method (before devirt)
// originalMethodHandle - method handle of base method (before devirt), including the profiled GVM instantiation
// pResolvedToken - resolved token for methodHandle, used to get R2R call info; nullptr when unavailable
// pUnboxedResolvedToken - resolved token for the unboxed entry, paired with pResolvedToken
//
Expand All @@ -8970,7 +8966,7 @@ void Compiler::addGuardedDevirtualizationCandidate(GenTreeCall* call,
CORINFO_RESOLVED_TOKEN* pUnboxedResolvedToken)
{
// This transformation only makes sense for delegate and virtual calls
assert(call->IsDelegateInvoke() || call->IsVirtual());
assert(call->IsDelegateInvoke() || call->IsVirtual() || call->IsGenericVirtual(this));

// Only mark calls if the feature is enabled.
const bool isEnabled = JitConfig.JitEnableGuardedDevirtualization() > 0;
Expand Down Expand Up @@ -9291,7 +9287,7 @@ void Compiler::impMarkInlineCandidateHelper(GenTreeCall* call,
return;
}

// Ignore indirect calls, unless they are indirect virtual stub calls with profile info.
// Ignore indirect calls, unless they are indirect virtual stub calls or generic virtual calls with profile info.
//
if (call->gtCallType == CT_INDIRECT)
{
Expand All @@ -9302,7 +9298,7 @@ void Compiler::impMarkInlineCandidateHelper(GenTreeCall* call,
}
else
{
assert(call->IsVirtualStub());
assert(call->IsVirtualStub() || call->IsGenericVirtual(this));
}
}

Expand Down Expand Up @@ -10588,7 +10584,7 @@ Compiler::GDVProbeType Compiler::compClassifyGDVProbeType(GenTreeCall* call)
bool createTypeHistogram = false;
if (JitConfig.JitClassProfiling() > 0)
{
createTypeHistogram = call->IsVirtualStub() || call->IsVirtualVtable();
createTypeHistogram = call->IsVirtualStub() || call->IsVirtualVtable() || call->IsGenericVirtual(this);

// Cast helpers may conditionally (depending on whether the class is
// exact or not) have probes. For those helpers we do not use this
Expand All @@ -10598,8 +10594,10 @@ Compiler::GDVProbeType Compiler::compClassifyGDVProbeType(GenTreeCall* call)
(call->gtHandleHistogramProfileCandidateInfo != nullptr));
}

bool createMethodHistogram = ((JitConfig.JitDelegateProfiling() > 0) && call->IsDelegateInvoke()) ||
((JitConfig.JitVTableProfiling() > 0) && call->IsVirtualVtable());
bool createMethodHistogram =
((JitConfig.JitDelegateProfiling() > 0) && call->IsDelegateInvoke()) ||
((JitConfig.JitVTableProfiling() > 0) && call->IsVirtualVtable()) ||
((JitConfig.JitGenericVirtualProfiling() > 0) && createTypeHistogram && call->IsGenericVirtual(this));

if (createTypeHistogram && createMethodHistogram)
{
Expand Down
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