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[clr-interp] Handle unmanaged thiscall on Windows Arm64 #123519

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Merged
davidwrighton merged 3 commits into from
Jan 23, 2026
+114 −20
Merged

[clr-interp] Handle unmanaged thiscall on Windows Arm64 #123519

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eb54507
[clr-interp] Handle unmanaged thiscall on Windows Arm64
davidwrighton Jan 22, 2026
4c36eb7
Update src/coreclr/vm/arm64/asmhelpers.asm
davidwrighton Jan 23, 2026
8c5a353
Merge branch 'main' of https://github.com/davidwrighton/runtime into …
davidwrighton Jan 23, 2026
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33 changes: 33 additions & 0 deletions src/coreclr/vm/arm64/asmhelpers.asm
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Original file line number Diff line number Diff line change
Expand Up @@ -1178,6 +1178,18 @@ HaveInterpThreadContext
EPILOG_RETURN
NESTED_END InterpreterStubRetBuff

NESTED_ENTRY InterpreterStubRetBuffX1
PROLOG_SAVE_REG_PAIR fp, lr, #-16!
; The +16 is for the fp, lr above
add x0, sp, #__PWTB_TransitionBlock + 16
; Load the return buffer address from incoming x1 before clobbering x1
mov x2, x1
mov x1, x19 ; the IR bytecode pointer
bl ExecuteInterpretedMethod
EPILOG_RESTORE_REG_PAIR fp, lr, #16!
EPILOG_RETURN
NESTED_END InterpreterStubRetBuffX1

NESTED_ENTRY InterpreterStubRet2I8
PROLOG_SAVE_REG_PAIR fp, lr, #-16!
; The +16 is for the fp, lr above
Expand Down Expand Up @@ -2601,6 +2613,27 @@ CopyLoop
EPILOG_RETURN
NESTED_END CallJittedMethodRetBuff

; X0 - routines array
; X1 - interpreter stack args location
; X2 - interpreter stack return value location
; X3 - stack arguments size (properly aligned)
; X4 - address of continuation return value
NESTED_ENTRY CallJittedMethodRetBuffX1
PROLOG_SAVE_REG_PAIR fp, lr, #-32!
str x4, [fp, #16]
sub sp, sp, x3
mov x10, x0
mov x9, x1
mov x1, x2
ldr x11, [x10], #8
blr x11
ldr x4, [fp, #16]
str x2, [x4]
EPILOG_STACK_RESTORE
EPILOG_RESTORE_REG_PAIR fp, lr, #32!
EPILOG_RETURN
NESTED_END CallJittedMethodRetBuffX1

; X0 - routines array
; X1 - interpreter stack args location
; X2 - interpreter stack return value location
Expand Down
45 changes: 39 additions & 6 deletions src/coreclr/vm/callingconvention.h
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Original file line number Diff line number Diff line change
Expand Up @@ -1091,7 +1091,15 @@ int ArgIteratorTemplate<ARGITERATOR_BASE>::GetRetBuffArgOffset()
// x86 is special as always
ret += this->HasThis() ? offsetof(ArgumentRegisters, EDX) : offsetof(ArgumentRegisters, ECX);
#elif TARGET_ARM64
ret = TransitionBlock::GetOffsetOfRetBuffArgReg();
if (this->IsRetBuffPassedAsFirstArg())
{
if (this->HasThis())
ret += TARGET_REGISTER_SIZE;
}
else
{
ret = TransitionBlock::GetOffsetOfRetBuffArgReg();
}
#else
if (this->HasThis())
ret += TARGET_REGISTER_SIZE;
Expand Down Expand Up @@ -1119,7 +1127,7 @@ int ArgIteratorTemplate<ARGITERATOR_BASE>::GetVASigCookieOffset()
ret += TARGET_REGISTER_SIZE;
}

if (this->HasRetBuffArg() && IsRetBuffPassedAsFirstArg())
if (this->HasRetBuffArg() && this->IsRetBuffPassedAsFirstArg())
{
ret += TARGET_REGISTER_SIZE;
}
Expand Down Expand Up @@ -1172,7 +1180,7 @@ int ArgIteratorTemplate<ARGITERATOR_BASE>::GetParamTypeArgOffset()
ret += TARGET_REGISTER_SIZE;
}

if (this->HasRetBuffArg() && IsRetBuffPassedAsFirstArg())
if (this->HasRetBuffArg() && this->IsRetBuffPassedAsFirstArg())
{
ret += TARGET_REGISTER_SIZE;
}
Expand Down Expand Up @@ -1229,7 +1237,7 @@ int ArgIteratorTemplate<ARGITERATOR_BASE>::GetAsyncContinuationArgOffset()
ret += TARGET_REGISTER_SIZE;
}

if (this->HasRetBuffArg() && IsRetBuffPassedAsFirstArg())
if (this->HasRetBuffArg() && this->IsRetBuffPassedAsFirstArg())
{
ret += TARGET_REGISTER_SIZE;
}
Expand Down Expand Up @@ -1265,7 +1273,7 @@ int ArgIteratorTemplate<ARGITERATOR_BASE>::GetNextOffset()
if (this->HasThis())
numRegistersUsed++;

if (this->HasRetBuffArg() && IsRetBuffPassedAsFirstArg())
if (this->HasRetBuffArg() && this->IsRetBuffPassedAsFirstArg())
numRegistersUsed++;

_ASSERTE(!this->IsVarArg() || !this->HasParamType());
Expand Down Expand Up @@ -2070,7 +2078,7 @@ void ArgIteratorTemplate<ARGITERATOR_BASE>::ForceSigWalk()
if (this->HasThis())
numRegistersUsed++;

if (this->HasRetBuffArg() && IsRetBuffPassedAsFirstArg())
if (this->HasRetBuffArg() && this->IsRetBuffPassedAsFirstArg())
numRegistersUsed++;

if (this->IsVarArg())
Expand Down Expand Up @@ -2267,6 +2275,11 @@ class ArgIteratorBase
#endif // defined(UNIX_AMD64_ABI)

public:
FORCEINLINE BOOL IsRetBuffPassedAsFirstArg()
{
return ::IsRetBuffPassedAsFirstArg();
}

BOOL HasThis()
{
LIMITED_METHOD_CONTRACT;
Expand Down Expand Up @@ -2361,6 +2374,26 @@ class PInvokeArgIterator : public ArgIteratorTemplate<ArgIteratorBaseForPInvoke>
}
};

#if defined(TARGET_ARM64) && defined(TARGET_WINDOWS)
class ArgIteratorBaseForWindowsArm64PInvokeThisCall : public ArgIteratorBaseForPInvoke
{
public:
FORCEINLINE BOOL IsRetBuffPassedAsFirstArg()
{
return TRUE;
}
};

class WindowsArm64PInvokeThisCallArgIterator : public ArgIteratorTemplate<ArgIteratorBaseForWindowsArm64PInvokeThisCall>
{
public:
WindowsArm64PInvokeThisCallArgIterator(MetaSig* pSig)
{
m_pSig = pSig;
}
};
#endif // defined(TARGET_ARM64) && defined(TARGET_WINDOWS)

// Conventience helper
inline BOOL HasRetBuffArg(MetaSig * pSig)
{
Expand Down
48 changes: 34 additions & 14 deletions src/coreclr/vm/callstubgenerator.cpp
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Expand Up @@ -2148,6 +2148,10 @@ extern "C" void CallJittedMethodRetBuffR1(PCODE *routines, int8_t*pArgs, int8_t*
extern "C" void InterpreterStubRetBuffR0();
extern "C" void InterpreterStubRetBuffR1();
#else // !TARGET_AMD64 && !TARGET_ARM
#if defined(TARGET_ARM64) && defined(TARGET_WINDOWS)
extern "C" void CallJittedMethodRetBuffX1(PCODE *routines, int8_t*pArgs, int8_t*pRet, int totalStackSize, PTR_PTR_Object pContinuation);
extern "C" void InterpreterStubRetBuffX1();
#endif
extern "C" void CallJittedMethodRetBuff(PCODE *routines, int8_t*pArgs, int8_t*pRet, int totalStackSize, PTR_PTR_Object pContinuation);
extern "C" void InterpreterStubRetBuff();
#endif // TARGET_AMD64
Expand Down Expand Up @@ -2256,12 +2260,17 @@ CallStubHeader::InvokeFunctionPtr CallStubGenerator::GetInvokeFunctionPtr(CallSt
case ReturnTypeBuffArg2:
INVOKE_FUNCTION_PTR(CallJittedMethodRetBuffRSI);
#endif // TARGET_WINDOWS
#elif defined(TARGET_ARM64) && defined(TARGET_WINDOWS)
case ReturnTypeBuffArg2:
INVOKE_FUNCTION_PTR(CallJittedMethodRetBuffX1);
case ReturnTypeBuff:
INVOKE_FUNCTION_PTR(CallJittedMethodRetBuff);
#elif defined(TARGET_ARM)
case ReturnTypeBuffArg1:
INVOKE_FUNCTION_PTR(CallJittedMethodRetBuffR0);
case ReturnTypeBuffArg2:
INVOKE_FUNCTION_PTR(CallJittedMethodRetBuffR1);
#else // !TARGET_AMD64 && !TARGET_ARM
#else // !TARGET_AMD64 && !TARGET_ARM && !(TARGET_ARM64 && TARGET_WINDOWS)
case ReturnTypeBuff:
INVOKE_FUNCTION_PTR(CallJittedMethodRetBuff);
#endif // TARGET_AMD64
Expand Down Expand Up @@ -2370,12 +2379,17 @@ PCODE CallStubGenerator::GetInterpreterReturnTypeHandler(CallStubGenerator::Retu
#else
RETURN_TYPE_HANDLER(InterpreterStubRetBuffRSI);
#endif
#elif defined(TARGET_ARM64) && defined(TARGET_WINDOWS)
case ReturnTypeBuffArg2:
RETURN_TYPE_HANDLER(InterpreterStubRetBuffX1);
case ReturnTypeBuff:
RETURN_TYPE_HANDLER(InterpreterStubRetBuff);
#elif defined(TARGET_ARM)
case ReturnTypeBuffArg1:
RETURN_TYPE_HANDLER(InterpreterStubRetBuffR0);
case ReturnTypeBuffArg2:
RETURN_TYPE_HANDLER(InterpreterStubRetBuffR1);
#else // !TARGET_AMD64 && !TARGET_ARM
#else // !TARGET_AMD64 && !TARGET_ARM && !(TARGET_ARM64 && TARGET_WINDOWS)
case ReturnTypeBuff:
RETURN_TYPE_HANDLER(InterpreterStubRetBuff);
#endif // TARGET_AMD64
Expand Down Expand Up @@ -2747,7 +2761,16 @@ void CallStubGenerator::ComputeCallStub(MetaSig &sig, PCODE *pRoutines, MethodDe

if (hasUnmanagedCallConv)
{
ComputeCallStubWorker<PInvokeArgIterator>(hasUnmanagedCallConv, unmanagedCallConv, sig, pRoutines, pMD);
#if defined(TARGET_ARM64) && defined(TARGET_WINDOWS)
if (callConvIsInstanceMethodCallConv(unmanagedCallConv))
{
ComputeCallStubWorker<WindowsArm64PInvokeThisCallArgIterator>(hasUnmanagedCallConv, unmanagedCallConv, sig, pRoutines, pMD);
}
else
#endif // defined(TARGET_ARM64) && defined(TARGET_WINDOWS)
{
ComputeCallStubWorker<PInvokeArgIterator>(hasUnmanagedCallConv, unmanagedCallConv, sig, pRoutines, pMD);
}
}
else
{
Expand All @@ -2763,17 +2786,7 @@ void CallStubGenerator::ComputeCallStubWorker(bool hasUnmanagedCallConv, CorInfo

if (hasUnmanagedCallConv)
{
switch (unmanagedCallConv)
{
case CorInfoCallConvExtension::Thiscall:
case CorInfoCallConvExtension::CMemberFunction:
case CorInfoCallConvExtension::StdcallMemberFunction:
case CorInfoCallConvExtension::FastcallMemberFunction:
unmanagedThisCallConv = true;
break;
default:
break;
}
unmanagedThisCallConv = callConvIsInstanceMethodCallConv(unmanagedCallConv);
}

#if defined(TARGET_WINDOWS)
Expand Down Expand Up @@ -3301,6 +3314,13 @@ CallStubGenerator::ReturnType CallStubGenerator::GetReturnType(ArgIteratorType *
return ReturnTypeBuffArg1;
}
#else
#if defined(TARGET_WINDOWS) && defined(TARGET_ARM64)
if (pArgIt->IsRetBuffPassedAsFirstArg())
{
_ASSERTE(pArgIt->HasThis());
return ReturnTypeBuffArg2;
}
#endif
return ReturnTypeBuff;
#endif // TARGET_AMD64
}
Expand Down
3 changes: 3 additions & 0 deletions src/coreclr/vm/callstubgenerator.h
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Expand Up @@ -83,6 +83,9 @@ class CallStubGenerator
ReturnTypeBuffArg1,
ReturnTypeBuffArg2,
#else
#if defined(TARGET_ARM64) && defined(TARGET_WINDOWS)
ReturnTypeBuffArg2,
#endif
ReturnTypeBuff,
#endif
#ifdef UNIX_AMD64_ABI
Expand Down
5 changes: 5 additions & 0 deletions src/coreclr/vm/reflectioninvocation.cpp
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Expand Up @@ -238,6 +238,11 @@ class ArgIteratorBaseForMethodInvoke
#endif // defined(UNIX_AMD64_ABI)

public:
FORCEINLINE BOOL IsRetBuffPassedAsFirstArg()
{
return ::IsRetBuffPassedAsFirstArg();
}

BOOL HasThis()
{
LIMITED_METHOD_CONTRACT;
Expand Down
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