HsiangKai created this revision.
HsiangKai added reviewers: craig.topper, frasercrmck, rogfer01.
Herald added a subscriber: StephenFan.
HsiangKai requested review of this revision.
Herald added a project: clang.
Herald added a subscriber: cfe-commits.
For scalable struct types, we do not know the exact size of the struct. Do not
use memcpy for struct copy. We use extractvalue and insertvalue for the purpose.
Repository:
rG LLVM Github Monorepo
https://reviews.llvm.org/D99590
Files:
clang/include/clang/AST/Type.h
clang/lib/AST/Type.cpp
clang/lib/CodeGen/CGExprAgg.cpp
Index: clang/lib/CodeGen/CGExprAgg.cpp
===================================================================
--- clang/lib/CodeGen/CGExprAgg.cpp
+++ clang/lib/CodeGen/CGExprAgg.cpp
@@ -2077,6 +2077,23 @@
}
}
+ // Aggregate assignment turns into element-by-element copy.
+ if (const RecordType *RecordTy = Ty->getAs<RecordType>()) {
+ if (RecordTy->hasSizelessFields()) {
+ RecordDecl *Record = RecordTy->getDecl();
+ llvm::Value *SrcVec = Builder.CreateLoad(SrcPtr);
+ llvm::Value *DestVec = llvm::UndefValue::get(ConvertType(Ty));
+ llvm::Value *Vec;
+ for (unsigned I = 0;
+ I < getContext().getASTRecordLayout(Record).getFieldCount(); ++I) {
+ Vec = Builder.CreateExtractValue(SrcVec, I);
+ DestVec = Builder.CreateInsertValue(DestVec, Vec, I);
+ }
+ Builder.CreateStore(DestVec, DestPtr);
+ return;
+ }
+ }
+
// Aggregate assignment turns into llvm.memcpy. This is almost valid per
// C99 6.5.16.1p3, which states "If the value being stored in an object is
// read from another object that overlaps in anyway the storage of the first
Index: clang/lib/AST/Type.cpp
===================================================================
--- clang/lib/AST/Type.cpp
+++ clang/lib/AST/Type.cpp
@@ -3510,6 +3510,28 @@
return false;
}
+bool RecordType::hasSizelessFields() const {
+ std::vector<const RecordType *> RecordTypeList;
+ RecordTypeList.push_back(this);
+ unsigned NextToCheckIndex = 0;
+
+ while (RecordTypeList.size() > NextToCheckIndex) {
+ for (FieldDecl *FD :
+ RecordTypeList[NextToCheckIndex]->getDecl()->fields()) {
+ QualType FieldTy = FD->getType();
+ if (FieldTy.getTypePtr()->isSizelessType())
+ return true;
+ FieldTy = FieldTy.getCanonicalType();
+ if (const auto *FieldRecTy = FieldTy->getAs<RecordType>()) {
+ if (llvm::find(RecordTypeList, FieldRecTy) == RecordTypeList.end())
+ RecordTypeList.push_back(FieldRecTy);
+ }
+ }
+ ++NextToCheckIndex;
+ }
+ return false;
+}
+
bool AttributedType::isQualifier() const {
// FIXME: Generate this with TableGen.
switch (getAttrKind()) {
Index: clang/include/clang/AST/Type.h
===================================================================
--- clang/include/clang/AST/Type.h
+++ clang/include/clang/AST/Type.h
@@ -4623,6 +4623,10 @@
/// is declared const, return true. Otherwise, return false.
bool hasConstFields() const;
+ /// Recursively check all fields in the record for sizeless. If any field
+ /// is sizeless type, return true. Otherwise, return false.
+ bool hasSizelessFields() const;
+
bool isSugared() const { return false; }
QualType desugar() const { return QualType(this, 0); }
Index: clang/lib/CodeGen/CGExprAgg.cpp
===================================================================
--- clang/lib/CodeGen/CGExprAgg.cpp
+++ clang/lib/CodeGen/CGExprAgg.cpp
@@ -2077,6 +2077,23 @@
}
}
+ // Aggregate assignment turns into element-by-element copy.
+ if (const RecordType *RecordTy = Ty->getAs<RecordType>()) {
+ if (RecordTy->hasSizelessFields()) {
+ RecordDecl *Record = RecordTy->getDecl();
+ llvm::Value *SrcVec = Builder.CreateLoad(SrcPtr);
+ llvm::Value *DestVec = llvm::UndefValue::get(ConvertType(Ty));
+ llvm::Value *Vec;
+ for (unsigned I = 0;
+ I < getContext().getASTRecordLayout(Record).getFieldCount(); ++I) {
+ Vec = Builder.CreateExtractValue(SrcVec, I);
+ DestVec = Builder.CreateInsertValue(DestVec, Vec, I);
+ }
+ Builder.CreateStore(DestVec, DestPtr);
+ return;
+ }
+ }
+
// Aggregate assignment turns into llvm.memcpy. This is almost valid per
// C99 6.5.16.1p3, which states "If the value being stored in an object is
// read from another object that overlaps in anyway the storage of the first
Index: clang/lib/AST/Type.cpp
===================================================================
--- clang/lib/AST/Type.cpp
+++ clang/lib/AST/Type.cpp
@@ -3510,6 +3510,28 @@
return false;
}
+bool RecordType::hasSizelessFields() const {
+ std::vector<const RecordType *> RecordTypeList;
+ RecordTypeList.push_back(this);
+ unsigned NextToCheckIndex = 0;
+
+ while (RecordTypeList.size() > NextToCheckIndex) {
+ for (FieldDecl *FD :
+ RecordTypeList[NextToCheckIndex]->getDecl()->fields()) {
+ QualType FieldTy = FD->getType();
+ if (FieldTy.getTypePtr()->isSizelessType())
+ return true;
+ FieldTy = FieldTy.getCanonicalType();
+ if (const auto *FieldRecTy = FieldTy->getAs<RecordType>()) {
+ if (llvm::find(RecordTypeList, FieldRecTy) == RecordTypeList.end())
+ RecordTypeList.push_back(FieldRecTy);
+ }
+ }
+ ++NextToCheckIndex;
+ }
+ return false;
+}
+
bool AttributedType::isQualifier() const {
// FIXME: Generate this with TableGen.
switch (getAttrKind()) {
Index: clang/include/clang/AST/Type.h
===================================================================
--- clang/include/clang/AST/Type.h
+++ clang/include/clang/AST/Type.h
@@ -4623,6 +4623,10 @@
/// is declared const, return true. Otherwise, return false.
bool hasConstFields() const;
+ /// Recursively check all fields in the record for sizeless. If any field
+ /// is sizeless type, return true. Otherwise, return false.
+ bool hasSizelessFields() const;
+
bool isSugared() const { return false; }
QualType desugar() const { return QualType(this, 0); }
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