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Only create MethodTable optional fields when needed #79435

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Merged
MichalStrehovsky merged 2 commits into from
Dec 10, 2022
Merged

Only create MethodTable optional fields when needed #79435

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c953ca1
Only create MethodTable optional fields when needed
MichalStrehovsky Dec 9, 2022
ecf5f0d
Hmm
MichalStrehovsky Dec 9, 2022
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24 changes: 15 additions & 9 deletions src/coreclr/nativeaot/Common/src/Internal/Runtime/MethodTable.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -858,10 +858,13 @@ internal bool HasDispatchMap
if (NumInterfaces == 0)
return false;
byte* optionalFields = OptionalFieldsPtr;
if (optionalFields == null)
return false;
uint idxDispatchMap = OptionalFieldsReader.GetInlineField(optionalFields, EETypeOptionalFieldTag.DispatchMap, 0xffffffff);
if (idxDispatchMap == 0xffffffff)

const uint NoDispatchMap = 0xffffffff;
uint idxDispatchMap = NoDispatchMap;
if (optionalFields != null)
idxDispatchMap = OptionalFieldsReader.GetInlineField(optionalFields, EETypeOptionalFieldTag.DispatchMap, NoDispatchMap);

if (idxDispatchMap == NoDispatchMap)
{
if (IsDynamicType)
return DynamicTemplateType->HasDispatchMap;
Expand All @@ -878,12 +881,15 @@ internal DispatchMap* DispatchMap
if (NumInterfaces == 0)
return null;
byte* optionalFields = OptionalFieldsPtr;
if (optionalFields == null)
return null;
uint idxDispatchMap = OptionalFieldsReader.GetInlineField(optionalFields, EETypeOptionalFieldTag.DispatchMap, 0xffffffff);
if (idxDispatchMap == 0xffffffff && IsDynamicType)
const uint NoDispatchMap = 0xffffffff;
uint idxDispatchMap = NoDispatchMap;
if (optionalFields != null)
idxDispatchMap = OptionalFieldsReader.GetInlineField(optionalFields, EETypeOptionalFieldTag.DispatchMap, NoDispatchMap);
if (idxDispatchMap == NoDispatchMap)
{
return DynamicTemplateType->DispatchMap;
if (IsDynamicType)
return DynamicTemplateType->DispatchMap;
return null;
}

if (SupportsRelativePointers)
Expand Down
19 changes: 12 additions & 7 deletions ...eclr/nativeaot/System.Private.TypeLoader/src/Internal/Runtime/TypeLoader/EETypeCreator.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -217,14 +217,18 @@ private static void CreateEETypeWorker(MethodTable* pTemplateEEType, uint hashCo
if (state.ThreadDataSize != 0)
rareFlags |= (uint)EETypeRareFlags.IsDynamicTypeWithThreadStatics;

optionalFields.SetFieldValue(EETypeOptionalFieldTag.RareFlags, rareFlags);
if (rareFlags != 0)
optionalFields.SetFieldValue(EETypeOptionalFieldTag.RareFlags, rareFlags);

// Dispatch map is fetched from template type
optionalFields.ClearField(EETypeOptionalFieldTag.DispatchMap);

// Compute size of optional fields encoding
cbOptionalFieldsSize = optionalFields.Encode();
Debug.Assert(cbOptionalFieldsSize > 0);

// Clear the optional fields flag. We'll set it if we set optional fields later in this method.
if (cbOptionalFieldsSize == 0)
flags &= ~(uint)EETypeFlags.OptionalFieldsFlag;

// Note: The number of vtable slots on the MethodTable to create is not necessary equal to the number of
// vtable slots on the template type for universal generics (see ComputeVTableLayout)
Expand All @@ -243,7 +247,7 @@ private static void CreateEETypeWorker(MethodTable* pTemplateEEType, uint hashCo
numVtableSlots,
runtimeInterfacesLength,
hasFinalizer,
true,
cbOptionalFieldsSize > 0,
(rareFlags & (int)EETypeRareFlags.HasSealedVTableEntriesFlag) != 0,
isGeneric,
allocatedNonGCDataSize != 0,
Expand Down Expand Up @@ -278,10 +282,11 @@ private static void CreateEETypeWorker(MethodTable* pTemplateEEType, uint hashCo
Debug.Assert(pEEType->HasGCPointers == (cbGCDesc != 0));

// Copy the encoded optional fields buffer to the newly allocated memory, and update the OptionalFields field on the MethodTable
// It is important to set the optional fields first on the newly created MethodTable, because all other 'setters'
// will assert that the type is dynamic, just to make sure we are not making any changes to statically compiled types
pEEType->OptionalFieldsPtr = (byte*)pEEType + cbEEType;
optionalFields.WriteToEEType(pEEType, cbOptionalFieldsSize);
if (cbOptionalFieldsSize > 0)
{
pEEType->OptionalFieldsPtr = (byte*)pEEType + cbEEType;
optionalFields.WriteToEEType(pEEType, cbOptionalFieldsSize);
}

// Copy VTable entries from template type
IntPtr* pVtable = (IntPtr*)((byte*)pEEType + sizeof(MethodTable));
Expand Down