[cfe-commits] r164853 - in /cfe/trunk: lib/CodeGen/CGExprAgg.cpp lib/CodeGen/CodeGenModule.cpp lib/CodeGen/CodeGenModule.h lib/CodeGen/CodeGenTBAA.cpp lib/CodeGen/CodeGenTBAA.h test/CodeGen/tbaa-struct.cpp
Dan Gohman
gohman at apple.com
Fri Sep 28 14:58:29 PDT 2012
Author: djg
Date: Fri Sep 28 16:58:29 2012
New Revision: 164853
URL: http://llvm.org/viewvc/llvm-project?rev=164853&view=rev
Log:
Add basic support for adding !tbaa.struct metadata on llvm.memcpy calls for
struct assignment.
Added:
cfe/trunk/test/CodeGen/tbaa-struct.cpp
Modified:
cfe/trunk/lib/CodeGen/CGExprAgg.cpp
cfe/trunk/lib/CodeGen/CodeGenModule.cpp
cfe/trunk/lib/CodeGen/CodeGenModule.h
cfe/trunk/lib/CodeGen/CodeGenTBAA.cpp
cfe/trunk/lib/CodeGen/CodeGenTBAA.h
Modified: cfe/trunk/lib/CodeGen/CGExprAgg.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGExprAgg.cpp?rev=164853&r1=164852&r2=164853&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGExprAgg.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGExprAgg.cpp Fri Sep 28 16:58:29 2012
@@ -1362,11 +1362,17 @@
}
}
}
+
+ // Determine the metadata to describe the position of any padding in this
+ // memcpy, as well as the TBAA tags for the members of the struct, in case
+ // the optimizer wishes to expand it in to scalar memory operations.
+ llvm::MDNode *TBAAStructTag = CGM.getTBAAStructInfo(Ty);
Builder.CreateMemCpy(DestPtr, SrcPtr,
llvm::ConstantInt::get(IntPtrTy,
TypeInfo.first.getQuantity()),
- alignment.getQuantity(), isVolatile);
+ alignment.getQuantity(), isVolatile,
+ /*TBAATag=*/0, TBAAStructTag);
}
void CodeGenFunction::MaybeEmitStdInitializerListCleanup(llvm::Value *loc,
Modified: cfe/trunk/lib/CodeGen/CodeGenModule.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CodeGenModule.cpp?rev=164853&r1=164852&r2=164853&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CodeGenModule.cpp (original)
+++ cfe/trunk/lib/CodeGen/CodeGenModule.cpp Fri Sep 28 16:58:29 2012
@@ -202,6 +202,12 @@
return TBAA->getTBAAInfoForVTablePtr();
}
+llvm::MDNode *CodeGenModule::getTBAAStructInfo(QualType QTy) {
+ if (!TBAA)
+ return 0;
+ return TBAA->getTBAAStructInfo(QTy);
+}
+
void CodeGenModule::DecorateInstruction(llvm::Instruction *Inst,
llvm::MDNode *TBAAInfo) {
Inst->setMetadata(llvm::LLVMContext::MD_tbaa, TBAAInfo);
Modified: cfe/trunk/lib/CodeGen/CodeGenModule.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CodeGenModule.h?rev=164853&r1=164852&r2=164853&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CodeGenModule.h (original)
+++ cfe/trunk/lib/CodeGen/CodeGenModule.h Fri Sep 28 16:58:29 2012
@@ -461,6 +461,7 @@
llvm::MDNode *getTBAAInfo(QualType QTy);
llvm::MDNode *getTBAAInfoForVTablePtr();
+ llvm::MDNode *getTBAAStructInfo(QualType QTy);
bool isTypeConstant(QualType QTy, bool ExcludeCtorDtor);
Modified: cfe/trunk/lib/CodeGen/CodeGenTBAA.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CodeGenTBAA.cpp?rev=164853&r1=164852&r2=164853&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CodeGenTBAA.cpp (original)
+++ cfe/trunk/lib/CodeGen/CodeGenTBAA.cpp Fri Sep 28 16:58:29 2012
@@ -17,6 +17,7 @@
#include "CodeGenTBAA.h"
#include "clang/AST/ASTContext.h"
+#include "clang/AST/RecordLayout.h"
#include "clang/AST/Mangle.h"
#include "clang/Frontend/CodeGenOptions.h"
#include "llvm/LLVMContext.h"
@@ -167,3 +168,59 @@
llvm::MDNode *CodeGenTBAA::getTBAAInfoForVTablePtr() {
return MDHelper.createTBAANode("vtable pointer", getRoot());
}
+
+bool
+CodeGenTBAA::CollectFields(uint64_t BaseOffset,
+ QualType QTy,
+ SmallVectorImpl<llvm::MDBuilder::TBAAStructField> &
+ Fields,
+ bool MayAlias) {
+ /* Things not handled yet include: C++ base classes, bitfields, */
+
+ if (const RecordType *TTy = QTy->getAs<RecordType>()) {
+ const RecordDecl *RD = TTy->getDecl()->getDefinition();
+ if (RD->hasFlexibleArrayMember())
+ return false;
+
+ // TODO: Handle C++ base classes.
+ if (const CXXRecordDecl *Decl = dyn_cast<CXXRecordDecl>(RD))
+ if (Decl->bases_begin() != Decl->bases_end())
+ return false;
+
+ const ASTRecordLayout &Layout = Context.getASTRecordLayout(RD);
+
+ unsigned idx = 0;
+ for (RecordDecl::field_iterator i = RD->field_begin(),
+ e = RD->field_end(); i != e; ++i, ++idx) {
+ uint64_t Offset = BaseOffset +
+ Layout.getFieldOffset(idx) / Context.getCharWidth();
+ QualType FieldQTy = i->getType();
+ if (!CollectFields(Offset, FieldQTy, Fields,
+ MayAlias || TypeHasMayAlias(FieldQTy)))
+ return false;
+ }
+ return true;
+ }
+
+ /* Otherwise, treat whatever it is as a field. */
+ uint64_t Offset = BaseOffset;
+ uint64_t Size = Context.getTypeSizeInChars(QTy).getQuantity();
+ llvm::MDNode *TBAAInfo = MayAlias ? getChar() : getTBAAInfo(QTy);
+ Fields.push_back(llvm::MDBuilder::TBAAStructField(Offset, Size, TBAAInfo));
+ return true;
+}
+
+llvm::MDNode *
+CodeGenTBAA::getTBAAStructInfo(QualType QTy) {
+ const Type *Ty = Context.getCanonicalType(QTy).getTypePtr();
+
+ if (llvm::MDNode *N = StructMetadataCache[Ty])
+ return N;
+
+ SmallVector<llvm::MDBuilder::TBAAStructField, 4> Fields;
+ if (CollectFields(0, QTy, Fields, TypeHasMayAlias(QTy)))
+ return MDHelper.createTBAAStructNode(Fields);
+
+ // For now, handle any other kind of type conservatively.
+ return StructMetadataCache[Ty] = NULL;
+}
Modified: cfe/trunk/lib/CodeGen/CodeGenTBAA.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CodeGenTBAA.h?rev=164853&r1=164852&r2=164853&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CodeGenTBAA.h (original)
+++ cfe/trunk/lib/CodeGen/CodeGenTBAA.h Fri Sep 28 16:58:29 2012
@@ -49,6 +49,10 @@
/// MetadataCache - This maps clang::Types to llvm::MDNodes describing them.
llvm::DenseMap<const Type *, llvm::MDNode *> MetadataCache;
+ /// StructMetadataCache - This maps clang::Types to llvm::MDNodes describing
+ /// them for struct assignments.
+ llvm::DenseMap<const Type *, llvm::MDNode *> StructMetadataCache;
+
llvm::MDNode *Root;
llvm::MDNode *Char;
@@ -60,6 +64,13 @@
/// considered to be equivalent to it.
llvm::MDNode *getChar();
+ /// CollectFields - Collect information about the fields of a type for
+ /// !tbaa.struct metadata formation. Return false for an unsupported type.
+ bool CollectFields(uint64_t BaseOffset,
+ QualType Ty,
+ SmallVectorImpl<llvm::MDBuilder::TBAAStructField> &Fields,
+ bool MayAlias);
+
public:
CodeGenTBAA(ASTContext &Ctx, llvm::LLVMContext &VMContext,
const CodeGenOptions &CGO,
@@ -74,6 +85,10 @@
/// getTBAAInfoForVTablePtr - Get the TBAA MDNode to be used for a
/// dereference of a vtable pointer.
llvm::MDNode *getTBAAInfoForVTablePtr();
+
+ /// getTBAAStructInfo - Get the TBAAStruct MDNode to be used for a memcpy of
+ /// the given type.
+ llvm::MDNode *getTBAAStructInfo(QualType QTy);
};
} // end namespace CodeGen
Added: cfe/trunk/test/CodeGen/tbaa-struct.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGen/tbaa-struct.cpp?rev=164853&view=auto
==============================================================================
--- cfe/trunk/test/CodeGen/tbaa-struct.cpp (added)
+++ cfe/trunk/test/CodeGen/tbaa-struct.cpp Fri Sep 28 16:58:29 2012
@@ -0,0 +1,16 @@
+// RUN: %clang_cc1 -emit-llvm -o - -O1 %s | FileCheck %s
+//
+// Check that we generate !tbaa.struct metadata for struct copies.
+struct A {
+ short s;
+ int i;
+ char c;
+ int j;
+};
+
+void copy(struct A *a, struct A *b) {
+ *a = *b;
+}
+
+// CHECK: call void @llvm.memcpy.p0i8.p0i8.i64(i8* %{{.*}}, i8* %{{.*}}, i64 16, i32 4, i1 false), !tbaa.struct [[TS:!.*]]
+// CHECK: [[TS]] = metadata !{i64 0, i64 2, metadata !{{.*}}, i64 4, i64 4, metadata !{{.*}}, i64 8, i64 1, metadata !{{.*}}, i64 12, i64 4, metadata !{{.*}}}
More information about the cfe-commits
mailing list