llvm-6502/include/llvm/IR/Metadata.h
Duncan P. N. Exon Smith 9ca230f11c IR: Move NumOperands from User to Value, NFC
Store `User::NumOperands` (and `MDNode::NumOperands`) in `Value`.

On 64-bit host architectures, this reduces `sizeof(User)` and all
subclasses by 8, and has no effect on `sizeof(Value)` (or, incidentally,
on `sizeof(MDNode)`).

On 32-bit host architectures, this increases `sizeof(Value)` by 4.
However, it has no effect on `sizeof(User)` and `sizeof(MDNode)`, so the
only concrete subclasses of `Value` that actually see the increase are
`BasicBlock`, `Argument`, `InlineAsm`, and `MDString`.  Moreover, I'll
be shocked and confused if this causes a tangible memory regression.

This has no functionality change (other than memory footprint).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219845 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-15 20:39:05 +00:00

337 lines
11 KiB
C++

//===-- llvm/Metadata.h - Metadata definitions ------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
/// @file
/// This file contains the declarations for metadata subclasses.
/// They represent the different flavors of metadata that live in LLVM.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_IR_METADATA_H
#define LLVM_IR_METADATA_H
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/FoldingSet.h"
#include "llvm/ADT/ilist_node.h"
#include "llvm/ADT/iterator_range.h"
#include "llvm/IR/Value.h"
namespace llvm {
class LLVMContext;
class Module;
template<typename ValueSubClass, typename ItemParentClass>
class SymbolTableListTraits;
enum LLVMConstants : uint32_t {
DEBUG_METADATA_VERSION = 2 // Current debug info version number.
};
//===----------------------------------------------------------------------===//
/// \brief A single uniqued string.
///
/// These are used to efficiently contain a byte sequence for metadata.
/// MDString is always unnamed.
class MDString : public Value {
virtual void anchor();
MDString(const MDString &) LLVM_DELETED_FUNCTION;
explicit MDString(LLVMContext &C);
public:
static MDString *get(LLVMContext &Context, StringRef Str);
static MDString *get(LLVMContext &Context, const char *Str) {
return get(Context, Str ? StringRef(Str) : StringRef());
}
StringRef getString() const { return getName(); }
unsigned getLength() const { return (unsigned)getName().size(); }
typedef StringRef::iterator iterator;
/// \brief Pointer to the first byte of the string.
iterator begin() const { return getName().begin(); }
/// \brief Pointer to one byte past the end of the string.
iterator end() const { return getName().end(); }
/// \brief Methods for support type inquiry through isa, cast, and dyn_cast.
static bool classof(const Value *V) {
return V->getValueID() == MDStringVal;
}
};
/// \brief A collection of metadata nodes that might be associated with a
/// memory access used by the alias-analysis infrastructure.
struct AAMDNodes {
explicit AAMDNodes(MDNode *T = nullptr, MDNode *S = nullptr,
MDNode *N = nullptr)
: TBAA(T), Scope(S), NoAlias(N) {}
bool operator==(const AAMDNodes &A) const {
return TBAA == A.TBAA && Scope == A.Scope && NoAlias == A.NoAlias;
}
bool operator!=(const AAMDNodes &A) const { return !(*this == A); }
LLVM_EXPLICIT operator bool() const { return TBAA || Scope || NoAlias; }
/// \brief The tag for type-based alias analysis.
MDNode *TBAA;
/// \brief The tag for alias scope specification (used with noalias).
MDNode *Scope;
/// \brief The tag specifying the noalias scope.
MDNode *NoAlias;
};
// Specialize DenseMapInfo for AAMDNodes.
template<>
struct DenseMapInfo<AAMDNodes> {
static inline AAMDNodes getEmptyKey() {
return AAMDNodes(DenseMapInfo<MDNode *>::getEmptyKey(), 0, 0);
}
static inline AAMDNodes getTombstoneKey() {
return AAMDNodes(DenseMapInfo<MDNode *>::getTombstoneKey(), 0, 0);
}
static unsigned getHashValue(const AAMDNodes &Val) {
return DenseMapInfo<MDNode *>::getHashValue(Val.TBAA) ^
DenseMapInfo<MDNode *>::getHashValue(Val.Scope) ^
DenseMapInfo<MDNode *>::getHashValue(Val.NoAlias);
}
static bool isEqual(const AAMDNodes &LHS, const AAMDNodes &RHS) {
return LHS == RHS;
}
};
class MDNodeOperand;
//===----------------------------------------------------------------------===//
/// \brief A tuple of other values.
class MDNode : public Value, public FoldingSetNode {
MDNode(const MDNode &) LLVM_DELETED_FUNCTION;
void operator=(const MDNode &) LLVM_DELETED_FUNCTION;
friend class MDNodeOperand;
friend class LLVMContextImpl;
friend struct FoldingSetTrait<MDNode>;
/// \brief If the MDNode is uniqued cache the hash to speed up lookup.
unsigned Hash;
/// \brief Subclass data enums.
enum {
/// FunctionLocalBit - This bit is set if this MDNode is function local.
/// This is true when it (potentially transitively) contains a reference to
/// something in a function, like an argument, basicblock, or instruction.
FunctionLocalBit = 1 << 0,
/// NotUniquedBit - This is set on MDNodes that are not uniqued because they
/// have a null operand.
NotUniquedBit = 1 << 1,
/// DestroyFlag - This bit is set by destroy() so the destructor can assert
/// that the node isn't being destroyed with a plain 'delete'.
DestroyFlag = 1 << 2
};
/// \brief FunctionLocal enums.
enum FunctionLocalness {
FL_Unknown = -1,
FL_No = 0,
FL_Yes = 1
};
/// \brief Replace each instance of the given operand with a new value.
void replaceOperand(MDNodeOperand *Op, Value *NewVal);
~MDNode();
MDNode(LLVMContext &C, ArrayRef<Value*> Vals, bool isFunctionLocal);
static MDNode *getMDNode(LLVMContext &C, ArrayRef<Value*> Vals,
FunctionLocalness FL, bool Insert = true);
public:
static MDNode *get(LLVMContext &Context, ArrayRef<Value*> Vals);
/// \brief Construct MDNode with an explicit function-localness.
///
/// Don't analyze Vals; trust isFunctionLocal.
static MDNode *getWhenValsUnresolved(LLVMContext &Context,
ArrayRef<Value*> Vals,
bool isFunctionLocal);
static MDNode *getIfExists(LLVMContext &Context, ArrayRef<Value*> Vals);
/// \brief Return a temporary MDNode
///
/// For use in constructing cyclic MDNode structures. A temporary MDNode is
/// not uniqued, may be RAUW'd, and must be manually deleted with
/// deleteTemporary.
static MDNode *getTemporary(LLVMContext &Context, ArrayRef<Value*> Vals);
/// \brief Deallocate a node created by getTemporary.
///
/// The node must not have any users.
static void deleteTemporary(MDNode *N);
/// \brief Replace a specific operand.
void replaceOperandWith(unsigned i, Value *NewVal);
/// \brief Return specified operand.
Value *getOperand(unsigned i) const LLVM_READONLY;
/// \brief Return number of MDNode operands.
unsigned getNumOperands() const { return NumOperands; }
/// \brief Return whether MDNode is local to a function.
bool isFunctionLocal() const {
return (getSubclassDataFromValue() & FunctionLocalBit) != 0;
}
/// \brief Return the first function-local operand's function.
///
/// If this metadata is function-local and recursively has a function-local
/// operand, return the first such operand's parent function. Otherwise,
/// return null. getFunction() should not be used for performance- critical
/// code because it recursively visits all the MDNode's operands.
const Function *getFunction() const;
/// \brief Calculate a unique identifier for this MDNode.
void Profile(FoldingSetNodeID &ID) const;
/// \brief Methods for support type inquiry through isa, cast, and dyn_cast:
static bool classof(const Value *V) {
return V->getValueID() == MDNodeVal;
}
/// \brief Check whether MDNode is a vtable access.
bool isTBAAVtableAccess() const;
/// \brief Methods for metadata merging.
static MDNode *concatenate(MDNode *A, MDNode *B);
static MDNode *intersect(MDNode *A, MDNode *B);
static MDNode *getMostGenericTBAA(MDNode *A, MDNode *B);
static AAMDNodes getMostGenericAA(const AAMDNodes &A, const AAMDNodes &B);
static MDNode *getMostGenericFPMath(MDNode *A, MDNode *B);
static MDNode *getMostGenericRange(MDNode *A, MDNode *B);
private:
/// \brief Delete this node. Only when there are no uses.
void destroy();
bool isNotUniqued() const {
return (getSubclassDataFromValue() & NotUniquedBit) != 0;
}
void setIsNotUniqued();
// Shadow Value::setValueSubclassData with a private forwarding method so that
// any future subclasses cannot accidentally use it.
void setValueSubclassData(unsigned short D) {
Value::setValueSubclassData(D);
}
};
//===----------------------------------------------------------------------===//
/// \brief A tuple of MDNodes.
///
/// Despite its name, a NamedMDNode isn't itself an MDNode. NamedMDNodes belong
/// to modules, have names, and contain lists of MDNodes.
class NamedMDNode : public ilist_node<NamedMDNode> {
friend class SymbolTableListTraits<NamedMDNode, Module>;
friend struct ilist_traits<NamedMDNode>;
friend class LLVMContextImpl;
friend class Module;
NamedMDNode(const NamedMDNode &) LLVM_DELETED_FUNCTION;
std::string Name;
Module *Parent;
void *Operands; // SmallVector<TrackingVH<MDNode>, 4>
void setParent(Module *M) { Parent = M; }
explicit NamedMDNode(const Twine &N);
template<class T1, class T2>
class op_iterator_impl :
public std::iterator<std::bidirectional_iterator_tag, T2> {
const NamedMDNode *Node;
unsigned Idx;
op_iterator_impl(const NamedMDNode *N, unsigned i) : Node(N), Idx(i) { }
friend class NamedMDNode;
public:
op_iterator_impl() : Node(nullptr), Idx(0) { }
bool operator==(const op_iterator_impl &o) const { return Idx == o.Idx; }
bool operator!=(const op_iterator_impl &o) const { return Idx != o.Idx; }
op_iterator_impl &operator++() {
++Idx;
return *this;
}
op_iterator_impl operator++(int) {
op_iterator_impl tmp(*this);
operator++();
return tmp;
}
op_iterator_impl &operator--() {
--Idx;
return *this;
}
op_iterator_impl operator--(int) {
op_iterator_impl tmp(*this);
operator--();
return tmp;
}
T1 operator*() const { return Node->getOperand(Idx); }
};
public:
/// \brief Drop all references and remove the node from parent module.
void eraseFromParent();
/// \brief Remove all uses and clear node vector.
void dropAllReferences();
~NamedMDNode();
/// \brief Get the module that holds this named metadata collection.
inline Module *getParent() { return Parent; }
inline const Module *getParent() const { return Parent; }
MDNode *getOperand(unsigned i) const;
unsigned getNumOperands() const;
void addOperand(MDNode *M);
StringRef getName() const;
void print(raw_ostream &ROS) const;
void dump() const;
// ---------------------------------------------------------------------------
// Operand Iterator interface...
//
typedef op_iterator_impl<MDNode*, MDNode> op_iterator;
op_iterator op_begin() { return op_iterator(this, 0); }
op_iterator op_end() { return op_iterator(this, getNumOperands()); }
typedef op_iterator_impl<const MDNode*, MDNode> const_op_iterator;
const_op_iterator op_begin() const { return const_op_iterator(this, 0); }
const_op_iterator op_end() const { return const_op_iterator(this, getNumOperands()); }
inline iterator_range<op_iterator> operands() {
return iterator_range<op_iterator>(op_begin(), op_end());
}
inline iterator_range<const_op_iterator> operands() const {
return iterator_range<const_op_iterator>(op_begin(), op_end());
}
};
} // end llvm namespace
#endif