kosarev created this revision.
kosarev added a project: clang.
This patch makes it possible to produce access tags in a uniform manner
regardless whether the resulting tag will be a scalar or a struct-path one.
getAccessTagInfo() now takes care of the actual translation of access
descriptors to tags and can handle all kinds of accesses. Facilities that
specific to scalar accesses are eliminated.
Some more details:
- DecorateInstructionWithTBAA() is not responsible for conversion of types to
access tags anymore. Instead, it takes an access descriptor (TBAAAccessInfo)
and generates corresponding access tag from it.
- getTBAAInfoForVTablePtr() reworked to getTBAAVTablePtrAccessInfo() that now
returns the virtual-pointer access descriptor and not the virtual-point type
metadata.
- Added function getTBAAMayAliasAccessInfo() that returns the descriptor for
may-alias accesses.
- getTBAAStructTagInfo() renamed to getTBAAAccessTagInfo() as now it is the
only way to generate access tag by a given access descriptor. It is capable of
producing both scalar and struct-path tags, depending on options and
availability of the base access type. getTBAAScalarTagInfo() and its cache
ScalarTagMetadataCache are eliminated.
- Now that we do not need to care about whether the resulting access tag should
be a scalar or struct-path one, getTBAAStructTypeInfo() is renamed to
getBaseTypeInfo().
- Added function getTBAAAccessInfo() that constructs access descriptor by a
given QualType access type.
This is part of https://reviews.llvm.org/D37826 reworked to be a separate patch
to simplify review.
Repository:
rL LLVM
https://reviews.llvm.org/D38503
Files:
lib/CodeGen/CGAtomic.cpp
lib/CodeGen/CGClass.cpp
lib/CodeGen/CGExpr.cpp
lib/CodeGen/CodeGenModule.cpp
lib/CodeGen/CodeGenModule.h
lib/CodeGen/CodeGenTBAA.cpp
lib/CodeGen/CodeGenTBAA.h
Index: lib/CodeGen/CodeGenTBAA.h
===================================================================
--- lib/CodeGen/CodeGenTBAA.h
+++ lib/CodeGen/CodeGenTBAA.h
@@ -86,8 +86,6 @@
llvm::DenseMap<const Type *, llvm::MDNode *> StructTypeMetadataCache;
/// This maps TBAAPathTags to a tag node.
llvm::DenseMap<TBAAPathTag, llvm::MDNode *> StructTagMetadataCache;
- /// This maps a scalar type to a scalar tag node.
- llvm::DenseMap<const llvm::MDNode *, llvm::MDNode *> ScalarTagMetadataCache;
/// StructMetadataCache - This maps clang::Types to llvm::MDNodes describing
/// them for struct assignments.
@@ -127,26 +125,23 @@
/// given type.
llvm::MDNode *getTypeInfo(QualType QTy);
- /// getTBAAInfoForVTablePtr - Get the TBAA MDNode to be used for a
- /// dereference of a vtable pointer.
- llvm::MDNode *getTBAAInfoForVTablePtr();
+ /// getVTablePtrAccessInfo - Get the TBAA information that describes an
+ /// access to a virtual table pointer.
+ TBAAAccessInfo getVTablePtrAccessInfo();
/// getTBAAStructInfo - Get the TBAAStruct MDNode to be used for a memcpy of
/// the given type.
llvm::MDNode *getTBAAStructInfo(QualType QTy);
- /// Get the MDNode in the type DAG for given struct type QType.
- llvm::MDNode *getTBAAStructTypeInfo(QualType QType);
+ /// getBaseTypeInfo - Get metadata node for a given base access type.
+ llvm::MDNode *getBaseTypeInfo(QualType QType);
- /// Get path-aware TBAA tag for a given memory access.
- llvm::MDNode *getTBAAStructTagInfo(TBAAAccessInfo Info);
+ /// getAccessTagInfo - Get TBAA tag for a given memory access.
+ llvm::MDNode *getAccessTagInfo(TBAAAccessInfo Info);
- /// Get the scalar tag MDNode for a given scalar type.
- llvm::MDNode *getTBAAScalarTagInfo(llvm::MDNode *AccessNode);
-
- /// getMayAliasTypeInfo - Get TBAA information that represents may-alias
+ /// getMayAliasAccessInfo - Get TBAA information that represents may-alias
/// accesses.
- llvm::MDNode *getMayAliasTypeInfo();
+ TBAAAccessInfo getMayAliasAccessInfo();
};
} // end namespace CodeGen
Index: lib/CodeGen/CodeGenTBAA.cpp
===================================================================
--- lib/CodeGen/CodeGenTBAA.cpp
+++ lib/CodeGen/CodeGenTBAA.cpp
@@ -171,8 +171,8 @@
return MetadataCache[Ty] = getChar();
}
-llvm::MDNode *CodeGenTBAA::getTBAAInfoForVTablePtr() {
- return createTBAAScalarType("vtable pointer", getRoot());
+TBAAAccessInfo CodeGenTBAA::getVTablePtrAccessInfo() {
+ return TBAAAccessInfo(createTBAAScalarType("vtable pointer", getRoot()));
}
bool
@@ -211,8 +211,8 @@
/* Otherwise, treat whatever it is as a field. */
uint64_t Offset = BaseOffset;
uint64_t Size = Context.getTypeSizeInChars(QTy).getQuantity();
- llvm::MDNode *TBAAInfo = MayAlias ? getChar() : getTypeInfo(QTy);
- llvm::MDNode *TBAATag = getTBAAScalarTagInfo(TBAAInfo);
+ llvm::MDNode *TBAAType = MayAlias ? getChar() : getTypeInfo(QTy);
+ llvm::MDNode *TBAATag = getAccessTagInfo(TBAAAccessInfo(TBAAType));
Fields.push_back(llvm::MDBuilder::TBAAStructField(Offset, Size, TBAATag));
return true;
}
@@ -232,8 +232,10 @@
return StructMetadataCache[Ty] = nullptr;
}
-/// Check if the given type can be handled by path-aware TBAA.
-static bool isTBAAPathStruct(QualType QTy) {
+/// Check if the given type is a valid base type to be used in access tags.
+static bool isValidBaseType(QualType QTy) {
+ if (QTy == QualType())
+ return false;
if (const RecordType *TTy = QTy->getAs<RecordType>()) {
const RecordDecl *RD = TTy->getDecl()->getDefinition();
if (RD->hasFlexibleArrayMember())
@@ -246,10 +248,9 @@
return false;
}
-llvm::MDNode *
-CodeGenTBAA::getTBAAStructTypeInfo(QualType QTy) {
+llvm::MDNode *CodeGenTBAA::getBaseTypeInfo(QualType QTy) {
const Type *Ty = Context.getCanonicalType(QTy).getTypePtr();
- assert(isTBAAPathStruct(QTy));
+ assert(isValidBaseType(QTy));
if (llvm::MDNode *N = StructTypeMetadataCache[Ty])
return N;
@@ -263,11 +264,8 @@
for (RecordDecl::field_iterator i = RD->field_begin(),
e = RD->field_end(); i != e; ++i, ++idx) {
QualType FieldQTy = i->getType();
- llvm::MDNode *FieldNode;
- if (isTBAAPathStruct(FieldQTy))
- FieldNode = getTBAAStructTypeInfo(FieldQTy);
- else
- FieldNode = getTypeInfo(FieldQTy);
+ llvm::MDNode *FieldNode = isValidBaseType(FieldQTy) ?
+ getBaseTypeInfo(FieldQTy) : getTypeInfo(FieldQTy);
if (!FieldNode)
return StructTypeMetadataCache[Ty] = nullptr;
Fields.push_back(std::make_pair(
@@ -290,21 +288,23 @@
return StructMetadataCache[Ty] = nullptr;
}
-llvm::MDNode *CodeGenTBAA::getTBAAStructTagInfo(TBAAAccessInfo Info) {
+llvm::MDNode *CodeGenTBAA::getAccessTagInfo(TBAAAccessInfo Info) {
if (!Info.AccessType)
return nullptr;
if (!CodeGenOpts.StructPathTBAA)
- return getTBAAScalarTagInfo(Info.AccessType);
+ Info = TBAAAccessInfo(Info.AccessType);
- const Type *BTy = Context.getCanonicalType(Info.BaseType).getTypePtr();
+ const Type *BTy = nullptr;
+ if (Info.BaseType != QualType())
+ BTy = Context.getCanonicalType(Info.BaseType).getTypePtr();
TBAAPathTag PathTag = TBAAPathTag(BTy, Info.AccessType, Info.Offset);
if (llvm::MDNode *N = StructTagMetadataCache[PathTag])
return N;
llvm::MDNode *BNode = nullptr;
- if (isTBAAPathStruct(Info.BaseType))
- BNode = getTBAAStructTypeInfo(Info.BaseType);
+ if (isValidBaseType(Info.BaseType))
+ BNode = getBaseTypeInfo(Info.BaseType);
if (!BNode)
return StructTagMetadataCache[PathTag] =
MDHelper.createTBAAStructTagNode(Info.AccessType, Info.AccessType,
@@ -314,17 +314,6 @@
MDHelper.createTBAAStructTagNode(BNode, Info.AccessType, Info.Offset);
}
-llvm::MDNode *
-CodeGenTBAA::getTBAAScalarTagInfo(llvm::MDNode *AccessNode) {
- if (!AccessNode)
- return nullptr;
- if (llvm::MDNode *N = ScalarTagMetadataCache[AccessNode])
- return N;
-
- return ScalarTagMetadataCache[AccessNode] =
- MDHelper.createTBAAStructTagNode(AccessNode, AccessNode, 0);
-}
-
-llvm::MDNode *CodeGenTBAA::getMayAliasTypeInfo() {
- return getChar();
+TBAAAccessInfo CodeGenTBAA::getMayAliasAccessInfo() {
+ return TBAAAccessInfo(getChar());
}
Index: lib/CodeGen/CodeGenModule.h
===================================================================
--- lib/CodeGen/CodeGenModule.h
+++ lib/CodeGen/CodeGenModule.h
@@ -656,28 +656,31 @@
/// the given type.
llvm::MDNode *getTBAATypeInfo(QualType QTy);
- llvm::MDNode *getTBAAInfoForVTablePtr();
+ /// getTBAAAccessInfo - Get TBAA information that describes an accesses to
+ /// an object of the given type.
+ TBAAAccessInfo getTBAAAccessInfo(QualType AccessType);
+
+ /// getTBAAVTablePtrAccessInfo - Get the TBAA information that describes an
+ /// access to a virtual table pointer.
+ TBAAAccessInfo getTBAAVTablePtrAccessInfo();
+
llvm::MDNode *getTBAAStructInfo(QualType QTy);
- /// Get path-aware TBAA tag for a given memory access.
- llvm::MDNode *getTBAAStructTagInfo(TBAAAccessInfo Info);
+ /// getTBAAAccessTagInfo - Get TBAA tag for a given memory access.
+ llvm::MDNode *getTBAAAccessTagInfo(TBAAAccessInfo Info);
- /// getTBAAMayAliasTypeInfo - Get TBAA information that represents
+ /// getTBAAMayAliasAccessInfo - Get TBAA information that represents
/// may-alias accesses.
- llvm::MDNode *getTBAAMayAliasTypeInfo();
+ TBAAAccessInfo getTBAAMayAliasAccessInfo();
bool isTypeConstant(QualType QTy, bool ExcludeCtorDtor);
bool isPaddedAtomicType(QualType type);
bool isPaddedAtomicType(const AtomicType *type);
- /// Decorate the instruction with a TBAA tag. For scalar TBAA, the tag
- /// is the same as the type. For struct-path aware TBAA, the tag
- /// is different from the type: base type, access type and offset.
- /// When ConvertTypeToTag is true, we create a tag based on the scalar type.
+ /// DecorateInstructionWithTBAA - Decorate the instruction with a TBAA tag.
void DecorateInstructionWithTBAA(llvm::Instruction *Inst,
- llvm::MDNode *TBAAInfo,
- bool ConvertTypeToTag = true);
+ TBAAAccessInfo TBAAInfo);
/// Adds !invariant.barrier !tag to instruction
void DecorateInstructionWithInvariantGroup(llvm::Instruction *I,
Index: lib/CodeGen/CodeGenModule.cpp
===================================================================
--- lib/CodeGen/CodeGenModule.cpp
+++ lib/CodeGen/CodeGenModule.cpp
@@ -578,42 +578,38 @@
return TBAA->getTypeInfo(QTy);
}
-llvm::MDNode *CodeGenModule::getTBAAInfoForVTablePtr() {
+TBAAAccessInfo CodeGenModule::getTBAAAccessInfo(QualType AccessType) {
+ return TBAAAccessInfo(getTBAATypeInfo(AccessType));
+}
+
+TBAAAccessInfo CodeGenModule::getTBAAVTablePtrAccessInfo() {
if (!TBAA)
- return nullptr;
- return TBAA->getTBAAInfoForVTablePtr();
+ return TBAAAccessInfo();
+ return TBAA->getVTablePtrAccessInfo();
}
llvm::MDNode *CodeGenModule::getTBAAStructInfo(QualType QTy) {
if (!TBAA)
return nullptr;
return TBAA->getTBAAStructInfo(QTy);
}
-llvm::MDNode *CodeGenModule::getTBAAStructTagInfo(TBAAAccessInfo Info) {
+llvm::MDNode *CodeGenModule::getTBAAAccessTagInfo(TBAAAccessInfo Info) {
if (!TBAA)
return nullptr;
- return TBAA->getTBAAStructTagInfo(Info);
+ return TBAA->getAccessTagInfo(Info);
}
-llvm::MDNode *CodeGenModule::getTBAAMayAliasTypeInfo() {
+TBAAAccessInfo CodeGenModule::getTBAAMayAliasAccessInfo() {
if (!TBAA)
- return nullptr;
- return TBAA->getMayAliasTypeInfo();
+ return TBAAAccessInfo();
+ return TBAA->getMayAliasAccessInfo();
}
-/// Decorate the instruction with a TBAA tag. For both scalar TBAA
-/// and struct-path aware TBAA, the tag has the same format:
-/// base type, access type and offset.
-/// When ConvertTypeToTag is true, we create a tag based on the scalar type.
void CodeGenModule::DecorateInstructionWithTBAA(llvm::Instruction *Inst,
- llvm::MDNode *TBAAInfo,
- bool ConvertTypeToTag) {
- if (ConvertTypeToTag && TBAA)
- Inst->setMetadata(llvm::LLVMContext::MD_tbaa,
- TBAA->getTBAAScalarTagInfo(TBAAInfo));
- else
- Inst->setMetadata(llvm::LLVMContext::MD_tbaa, TBAAInfo);
+ TBAAAccessInfo TBAAInfo) {
+ if (llvm::MDNode *Tag = getTBAAAccessTagInfo(TBAAInfo))
+ Inst->setMetadata(llvm::LLVMContext::MD_tbaa, Tag);
}
void CodeGenModule::DecorateInstructionWithInvariantGroup(
Index: lib/CodeGen/CGExpr.cpp
===================================================================
--- lib/CodeGen/CGExpr.cpp
+++ lib/CodeGen/CGExpr.cpp
@@ -1526,12 +1526,9 @@
Load->setMetadata(CGM.getModule().getMDKindID("nontemporal"), Node);
}
if (TBAAInfo.AccessType) {
- bool MayAlias = BaseInfo.getMayAlias();
- llvm::MDNode *TBAA = MayAlias
- ? CGM.getTBAAMayAliasTypeInfo()
- : CGM.getTBAAStructTagInfo(TBAAInfo);
- if (TBAA)
- CGM.DecorateInstructionWithTBAA(Load, TBAA, MayAlias);
+ if (BaseInfo.getMayAlias())
+ TBAAInfo = CGM.getTBAAMayAliasAccessInfo();
+ CGM.DecorateInstructionWithTBAA(Load, TBAAInfo);
}
if (EmitScalarRangeCheck(Load, Ty, Loc)) {
@@ -1614,12 +1611,9 @@
Store->setMetadata(CGM.getModule().getMDKindID("nontemporal"), Node);
}
if (TBAAInfo.AccessType) {
- bool MayAlias = BaseInfo.getMayAlias();
- llvm::MDNode *TBAA = MayAlias
- ? CGM.getTBAAMayAliasTypeInfo()
- : CGM.getTBAAStructTagInfo(TBAAInfo);
- if (TBAA)
- CGM.DecorateInstructionWithTBAA(Store, TBAA, MayAlias);
+ if (BaseInfo.getMayAlias())
+ TBAAInfo = CGM.getTBAAMayAliasAccessInfo();
+ CGM.DecorateInstructionWithTBAA(Store, TBAAInfo);
}
}
@@ -3727,12 +3721,9 @@
// Loading the reference will disable path-aware TBAA.
TBAAPath = false;
- if (CGM.shouldUseTBAA()) {
- llvm::MDNode *tbaa = mayAlias ? CGM.getTBAAMayAliasTypeInfo() :
- CGM.getTBAATypeInfo(type);
- if (tbaa)
- CGM.DecorateInstructionWithTBAA(load, tbaa);
- }
+ TBAAAccessInfo TBAAInfo = mayAlias ? CGM.getTBAAMayAliasAccessInfo() :
+ CGM.getTBAAAccessInfo(type);
+ CGM.DecorateInstructionWithTBAA(load, TBAAInfo);
mayAlias = false;
type = refType->getPointeeType();
@@ -3769,7 +3760,7 @@
// update offset to be relative to the base type.
unsigned CharWidth = getContext().getCharWidth();
TBAAAccessInfo TBAAInfo = mayAlias ?
- TBAAAccessInfo(CGM.getTBAAMayAliasTypeInfo()) :
+ CGM.getTBAAMayAliasAccessInfo() :
TBAAAccessInfo(base.getTBAAInfo().BaseType, CGM.getTBAATypeInfo(type),
base.getTBAAInfo().Offset + Layout.getFieldOffset(
field->getFieldIndex()) / CharWidth);
@@ -3784,7 +3775,7 @@
// FIXME: this should get propagated down through anonymous structs
// and unions.
if (mayAlias && LV.getTBAAAccessType())
- LV.setTBAAAccessType(CGM.getTBAAMayAliasTypeInfo());
+ LV.setTBAAInfo(CGM.getTBAAMayAliasAccessInfo());
return LV;
}
Index: lib/CodeGen/CGClass.cpp
===================================================================
--- lib/CodeGen/CGClass.cpp
+++ lib/CodeGen/CGClass.cpp
@@ -2383,7 +2383,7 @@
VTableAddressPoint = Builder.CreateBitCast(VTableAddressPoint, VTablePtrTy);
llvm::StoreInst *Store = Builder.CreateStore(VTableAddressPoint, VTableField);
- CGM.DecorateInstructionWithTBAA(Store, CGM.getTBAAInfoForVTablePtr());
+ CGM.DecorateInstructionWithTBAA(Store, CGM.getTBAAVTablePtrAccessInfo());
if (CGM.getCodeGenOpts().OptimizationLevel > 0 &&
CGM.getCodeGenOpts().StrictVTablePointers)
CGM.DecorateInstructionWithInvariantGroup(Store, Vptr.VTableClass);
@@ -2477,7 +2477,7 @@
const CXXRecordDecl *RD) {
Address VTablePtrSrc = Builder.CreateElementBitCast(This, VTableTy);
llvm::Instruction *VTable = Builder.CreateLoad(VTablePtrSrc, "vtable");
- CGM.DecorateInstructionWithTBAA(VTable, CGM.getTBAAInfoForVTablePtr());
+ CGM.DecorateInstructionWithTBAA(VTable, CGM.getTBAAVTablePtrAccessInfo());
if (CGM.getCodeGenOpts().OptimizationLevel > 0 &&
CGM.getCodeGenOpts().StrictVTablePointers)
Index: lib/CodeGen/CGAtomic.cpp
===================================================================
--- lib/CodeGen/CGAtomic.cpp
+++ lib/CodeGen/CGAtomic.cpp
@@ -1425,8 +1425,8 @@
// Other decoration.
if (IsVolatile)
Load->setVolatile(true);
- if (LVal.getTBAAAccessType())
- CGF.CGM.DecorateInstructionWithTBAA(Load, LVal.getTBAAAccessType());
+ TBAAAccessInfo TBAAInfo(LVal.getTBAAAccessType());
+ CGF.CGM.DecorateInstructionWithTBAA(Load, TBAAInfo);
return Load;
}
@@ -1942,8 +1942,8 @@
// Other decoration.
if (IsVolatile)
store->setVolatile(true);
- if (dest.getTBAAAccessType())
- CGM.DecorateInstructionWithTBAA(store, dest.getTBAAAccessType());
+ TBAAAccessInfo TBAAInfo(dest.getTBAAAccessType());
+ CGM.DecorateInstructionWithTBAA(store, TBAAInfo);
return;
}
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