llvm-6502/include/llvm/IR/Value.h
Pete Cooper a641a4a89e Store intrinsic ID by value in Function instead of a string lookup. NFC.
On 64-bit targets, Function has 4-bytes of padding in its struct layout.

This uses the space for the intrinsic ID. It is set and recalculated whenever the function name is set.  This is similar to the current behavior which clears the function from the intrinsic ID cache when its renamed.

The intrinsic cache itself is removed as the only purpose was to speedup calls to getIntrinsicID() which now just reading the new field in the struct.

Reviewed by Duncan.  http://reviews.llvm.org/D9836

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237642 91177308-0d34-0410-b5e6-96231b3b80d8
2015-05-19 00:24:26 +00:00

715 lines
24 KiB
C++

//===-- llvm/Value.h - Definition of the Value class ------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file declares the Value class.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_IR_VALUE_H
#define LLVM_IR_VALUE_H
#include "llvm-c/Core.h"
#include "llvm/ADT/iterator_range.h"
#include "llvm/IR/Use.h"
#include "llvm/Support/CBindingWrapping.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/Compiler.h"
namespace llvm {
class APInt;
class Argument;
class AssemblyAnnotationWriter;
class BasicBlock;
class Constant;
class DataLayout;
class Function;
class GlobalAlias;
class GlobalObject;
class GlobalValue;
class GlobalVariable;
class InlineAsm;
class Instruction;
class LLVMContext;
class Module;
class StringRef;
class Twine;
class Type;
class ValueHandleBase;
class ValueSymbolTable;
class raw_ostream;
template<typename ValueTy> class StringMapEntry;
typedef StringMapEntry<Value*> ValueName;
//===----------------------------------------------------------------------===//
// Value Class
//===----------------------------------------------------------------------===//
/// \brief LLVM Value Representation
///
/// This is a very important LLVM class. It is the base class of all values
/// computed by a program that may be used as operands to other values. Value is
/// the super class of other important classes such as Instruction and Function.
/// All Values have a Type. Type is not a subclass of Value. Some values can
/// have a name and they belong to some Module. Setting the name on the Value
/// automatically updates the module's symbol table.
///
/// Every value has a "use list" that keeps track of which other Values are
/// using this Value. A Value can also have an arbitrary number of ValueHandle
/// objects that watch it and listen to RAUW and Destroy events. See
/// llvm/IR/ValueHandle.h for details.
class Value {
Type *VTy;
Use *UseList;
friend class ValueAsMetadata; // Allow access to NameAndIsUsedByMD.
friend class ValueHandleBase;
PointerIntPair<ValueName *, 1> NameAndIsUsedByMD;
const unsigned char SubclassID; // Subclass identifier (for isa/dyn_cast)
unsigned char HasValueHandle : 1; // Has a ValueHandle pointing to this?
protected:
/// \brief Hold subclass data that can be dropped.
///
/// This member is similar to SubclassData, however it is for holding
/// information which may be used to aid optimization, but which may be
/// cleared to zero without affecting conservative interpretation.
unsigned char SubclassOptionalData : 7;
private:
/// \brief Hold arbitrary subclass data.
///
/// This member is defined by this class, but is not used for anything.
/// Subclasses can use it to hold whatever state they find useful. This
/// field is initialized to zero by the ctor.
unsigned short SubclassData;
protected:
/// \brief The number of operands in the subclass.
///
/// This member is defined by this class, but not used for anything.
/// Subclasses can use it to store their number of operands, if they have
/// any.
///
/// This is stored here to save space in User on 64-bit hosts. Since most
/// instances of Value have operands, 32-bit hosts aren't significantly
/// affected.
unsigned NumOperands;
private:
template <typename UseT> // UseT == 'Use' or 'const Use'
class use_iterator_impl
: public std::iterator<std::forward_iterator_tag, UseT *> {
UseT *U;
explicit use_iterator_impl(UseT *u) : U(u) {}
friend class Value;
public:
use_iterator_impl() : U() {}
bool operator==(const use_iterator_impl &x) const { return U == x.U; }
bool operator!=(const use_iterator_impl &x) const { return !operator==(x); }
use_iterator_impl &operator++() { // Preincrement
assert(U && "Cannot increment end iterator!");
U = U->getNext();
return *this;
}
use_iterator_impl operator++(int) { // Postincrement
auto tmp = *this;
++*this;
return tmp;
}
UseT &operator*() const {
assert(U && "Cannot dereference end iterator!");
return *U;
}
UseT *operator->() const { return &operator*(); }
operator use_iterator_impl<const UseT>() const {
return use_iterator_impl<const UseT>(U);
}
};
template <typename UserTy> // UserTy == 'User' or 'const User'
class user_iterator_impl
: public std::iterator<std::forward_iterator_tag, UserTy *> {
use_iterator_impl<Use> UI;
explicit user_iterator_impl(Use *U) : UI(U) {}
friend class Value;
public:
user_iterator_impl() {}
bool operator==(const user_iterator_impl &x) const { return UI == x.UI; }
bool operator!=(const user_iterator_impl &x) const { return !operator==(x); }
/// \brief Returns true if this iterator is equal to user_end() on the value.
bool atEnd() const { return *this == user_iterator_impl(); }
user_iterator_impl &operator++() { // Preincrement
++UI;
return *this;
}
user_iterator_impl operator++(int) { // Postincrement
auto tmp = *this;
++*this;
return tmp;
}
// Retrieve a pointer to the current User.
UserTy *operator*() const {
return UI->getUser();
}
UserTy *operator->() const { return operator*(); }
operator user_iterator_impl<const UserTy>() const {
return user_iterator_impl<const UserTy>(*UI);
}
Use &getUse() const { return *UI; }
};
void operator=(const Value &) = delete;
Value(const Value &) = delete;
protected:
Value(Type *Ty, unsigned scid);
public:
virtual ~Value();
/// \brief Support for debugging, callable in GDB: V->dump()
void dump() const;
/// \brief Implement operator<< on Value.
void print(raw_ostream &O) const;
/// \brief Print the name of this Value out to the specified raw_ostream.
///
/// This is useful when you just want to print 'int %reg126', not the
/// instruction that generated it. If you specify a Module for context, then
/// even constanst get pretty-printed; for example, the type of a null
/// pointer is printed symbolically.
void printAsOperand(raw_ostream &O, bool PrintType = true,
const Module *M = nullptr) const;
/// \brief All values are typed, get the type of this value.
Type *getType() const { return VTy; }
/// \brief All values hold a context through their type.
LLVMContext &getContext() const;
// \brief All values can potentially be named.
bool hasName() const { return getValueName() != nullptr; }
ValueName *getValueName() const { return NameAndIsUsedByMD.getPointer(); }
void setValueName(ValueName *VN) { NameAndIsUsedByMD.setPointer(VN); }
private:
void destroyValueName();
void setNameImpl(const Twine &Name);
public:
/// \brief Return a constant reference to the value's name.
///
/// This is cheap and guaranteed to return the same reference as long as the
/// value is not modified.
StringRef getName() const;
/// \brief Change the name of the value.
///
/// Choose a new unique name if the provided name is taken.
///
/// \param Name The new name; or "" if the value's name should be removed.
void setName(const Twine &Name);
/// \brief Transfer the name from V to this value.
///
/// After taking V's name, sets V's name to empty.
///
/// \note It is an error to call V->takeName(V).
void takeName(Value *V);
/// \brief Change all uses of this to point to a new Value.
///
/// Go through the uses list for this definition and make each use point to
/// "V" instead of "this". After this completes, 'this's use list is
/// guaranteed to be empty.
void replaceAllUsesWith(Value *V);
/// replaceUsesOutsideBlock - Go through the uses list for this definition and
/// make each use point to "V" instead of "this" when the use is outside the
/// block. 'This's use list is expected to have at least one element.
/// Unlike replaceAllUsesWith this function does not support basic block
/// values or constant users.
void replaceUsesOutsideBlock(Value *V, BasicBlock *BB);
//----------------------------------------------------------------------
// Methods for handling the chain of uses of this Value.
//
bool use_empty() const { return UseList == nullptr; }
typedef use_iterator_impl<Use> use_iterator;
typedef use_iterator_impl<const Use> const_use_iterator;
use_iterator use_begin() { return use_iterator(UseList); }
const_use_iterator use_begin() const { return const_use_iterator(UseList); }
use_iterator use_end() { return use_iterator(); }
const_use_iterator use_end() const { return const_use_iterator(); }
iterator_range<use_iterator> uses() {
return iterator_range<use_iterator>(use_begin(), use_end());
}
iterator_range<const_use_iterator> uses() const {
return iterator_range<const_use_iterator>(use_begin(), use_end());
}
bool user_empty() const { return UseList == nullptr; }
typedef user_iterator_impl<User> user_iterator;
typedef user_iterator_impl<const User> const_user_iterator;
user_iterator user_begin() { return user_iterator(UseList); }
const_user_iterator user_begin() const { return const_user_iterator(UseList); }
user_iterator user_end() { return user_iterator(); }
const_user_iterator user_end() const { return const_user_iterator(); }
User *user_back() { return *user_begin(); }
const User *user_back() const { return *user_begin(); }
iterator_range<user_iterator> users() {
return iterator_range<user_iterator>(user_begin(), user_end());
}
iterator_range<const_user_iterator> users() const {
return iterator_range<const_user_iterator>(user_begin(), user_end());
}
/// \brief Return true if there is exactly one user of this value.
///
/// This is specialized because it is a common request and does not require
/// traversing the whole use list.
bool hasOneUse() const {
const_use_iterator I = use_begin(), E = use_end();
if (I == E) return false;
return ++I == E;
}
/// \brief Return true if this Value has exactly N users.
bool hasNUses(unsigned N) const;
/// \brief Return true if this value has N users or more.
///
/// This is logically equivalent to getNumUses() >= N.
bool hasNUsesOrMore(unsigned N) const;
/// \brief Check if this value is used in the specified basic block.
bool isUsedInBasicBlock(const BasicBlock *BB) const;
/// \brief This method computes the number of uses of this Value.
///
/// This is a linear time operation. Use hasOneUse, hasNUses, or
/// hasNUsesOrMore to check for specific values.
unsigned getNumUses() const;
/// \brief This method should only be used by the Use class.
void addUse(Use &U) { U.addToList(&UseList); }
/// \brief Concrete subclass of this.
///
/// An enumeration for keeping track of the concrete subclass of Value that
/// is actually instantiated. Values of this enumeration are kept in the
/// Value classes SubclassID field. They are used for concrete type
/// identification.
enum ValueTy {
ArgumentVal, // This is an instance of Argument
BasicBlockVal, // This is an instance of BasicBlock
FunctionVal, // This is an instance of Function
GlobalAliasVal, // This is an instance of GlobalAlias
GlobalVariableVal, // This is an instance of GlobalVariable
UndefValueVal, // This is an instance of UndefValue
BlockAddressVal, // This is an instance of BlockAddress
ConstantExprVal, // This is an instance of ConstantExpr
ConstantAggregateZeroVal, // This is an instance of ConstantAggregateZero
ConstantDataArrayVal, // This is an instance of ConstantDataArray
ConstantDataVectorVal, // This is an instance of ConstantDataVector
ConstantIntVal, // This is an instance of ConstantInt
ConstantFPVal, // This is an instance of ConstantFP
ConstantArrayVal, // This is an instance of ConstantArray
ConstantStructVal, // This is an instance of ConstantStruct
ConstantVectorVal, // This is an instance of ConstantVector
ConstantPointerNullVal, // This is an instance of ConstantPointerNull
MetadataAsValueVal, // This is an instance of MetadataAsValue
InlineAsmVal, // This is an instance of InlineAsm
InstructionVal, // This is an instance of Instruction
// Enum values starting at InstructionVal are used for Instructions;
// don't add new values here!
// Markers:
ConstantFirstVal = FunctionVal,
ConstantLastVal = ConstantPointerNullVal
};
/// \brief Return an ID for the concrete type of this object.
///
/// This is used to implement the classof checks. This should not be used
/// for any other purpose, as the values may change as LLVM evolves. Also,
/// note that for instructions, the Instruction's opcode is added to
/// InstructionVal. So this means three things:
/// # there is no value with code InstructionVal (no opcode==0).
/// # there are more possible values for the value type than in ValueTy enum.
/// # the InstructionVal enumerator must be the highest valued enumerator in
/// the ValueTy enum.
unsigned getValueID() const {
return SubclassID;
}
/// \brief Return the raw optional flags value contained in this value.
///
/// This should only be used when testing two Values for equivalence.
unsigned getRawSubclassOptionalData() const {
return SubclassOptionalData;
}
/// \brief Clear the optional flags contained in this value.
void clearSubclassOptionalData() {
SubclassOptionalData = 0;
}
/// \brief Check the optional flags for equality.
bool hasSameSubclassOptionalData(const Value *V) const {
return SubclassOptionalData == V->SubclassOptionalData;
}
/// \brief Clear any optional flags not set in the given Value.
void intersectOptionalDataWith(const Value *V) {
SubclassOptionalData &= V->SubclassOptionalData;
}
/// \brief Return true if there is a value handle associated with this value.
bool hasValueHandle() const { return HasValueHandle; }
/// \brief Return true if there is metadata referencing this value.
bool isUsedByMetadata() const { return NameAndIsUsedByMD.getInt(); }
/// \brief Strip off pointer casts, all-zero GEPs, and aliases.
///
/// Returns the original uncasted value. If this is called on a non-pointer
/// value, it returns 'this'.
Value *stripPointerCasts();
const Value *stripPointerCasts() const {
return const_cast<Value*>(this)->stripPointerCasts();
}
/// \brief Strip off pointer casts and all-zero GEPs.
///
/// Returns the original uncasted value. If this is called on a non-pointer
/// value, it returns 'this'.
Value *stripPointerCastsNoFollowAliases();
const Value *stripPointerCastsNoFollowAliases() const {
return const_cast<Value*>(this)->stripPointerCastsNoFollowAliases();
}
/// \brief Strip off pointer casts and all-constant inbounds GEPs.
///
/// Returns the original pointer value. If this is called on a non-pointer
/// value, it returns 'this'.
Value *stripInBoundsConstantOffsets();
const Value *stripInBoundsConstantOffsets() const {
return const_cast<Value*>(this)->stripInBoundsConstantOffsets();
}
/// \brief Accumulate offsets from \a stripInBoundsConstantOffsets().
///
/// Stores the resulting constant offset stripped into the APInt provided.
/// The provided APInt will be extended or truncated as needed to be the
/// correct bitwidth for an offset of this pointer type.
///
/// If this is called on a non-pointer value, it returns 'this'.
Value *stripAndAccumulateInBoundsConstantOffsets(const DataLayout &DL,
APInt &Offset);
const Value *stripAndAccumulateInBoundsConstantOffsets(const DataLayout &DL,
APInt &Offset) const {
return const_cast<Value *>(this)
->stripAndAccumulateInBoundsConstantOffsets(DL, Offset);
}
/// \brief Strip off pointer casts and inbounds GEPs.
///
/// Returns the original pointer value. If this is called on a non-pointer
/// value, it returns 'this'.
Value *stripInBoundsOffsets();
const Value *stripInBoundsOffsets() const {
return const_cast<Value*>(this)->stripInBoundsOffsets();
}
/// \brief Translate PHI node to its predecessor from the given basic block.
///
/// If this value is a PHI node with CurBB as its parent, return the value in
/// the PHI node corresponding to PredBB. If not, return ourself. This is
/// useful if you want to know the value something has in a predecessor
/// block.
Value *DoPHITranslation(const BasicBlock *CurBB, const BasicBlock *PredBB);
const Value *DoPHITranslation(const BasicBlock *CurBB,
const BasicBlock *PredBB) const{
return const_cast<Value*>(this)->DoPHITranslation(CurBB, PredBB);
}
/// \brief The maximum alignment for instructions.
///
/// This is the greatest alignment value supported by load, store, and alloca
/// instructions, and global values.
static const unsigned MaxAlignmentExponent = 29;
static const unsigned MaximumAlignment = 1u << MaxAlignmentExponent;
/// \brief Mutate the type of this Value to be of the specified type.
///
/// Note that this is an extremely dangerous operation which can create
/// completely invalid IR very easily. It is strongly recommended that you
/// recreate IR objects with the right types instead of mutating them in
/// place.
void mutateType(Type *Ty) {
VTy = Ty;
}
/// \brief Sort the use-list.
///
/// Sorts the Value's use-list by Cmp using a stable mergesort. Cmp is
/// expected to compare two \a Use references.
template <class Compare> void sortUseList(Compare Cmp);
/// \brief Reverse the use-list.
void reverseUseList();
private:
/// \brief Merge two lists together.
///
/// Merges \c L and \c R using \c Cmp. To enable stable sorts, always pushes
/// "equal" items from L before items from R.
///
/// \return the first element in the list.
///
/// \note Completely ignores \a Use::Prev (doesn't read, doesn't update).
template <class Compare>
static Use *mergeUseLists(Use *L, Use *R, Compare Cmp) {
Use *Merged;
mergeUseListsImpl(L, R, &Merged, Cmp);
return Merged;
}
/// \brief Tail-recursive helper for \a mergeUseLists().
///
/// \param[out] Next the first element in the list.
template <class Compare>
static void mergeUseListsImpl(Use *L, Use *R, Use **Next, Compare Cmp);
protected:
unsigned short getSubclassDataFromValue() const { return SubclassData; }
void setValueSubclassData(unsigned short D) { SubclassData = D; }
};
inline raw_ostream &operator<<(raw_ostream &OS, const Value &V) {
V.print(OS);
return OS;
}
void Use::set(Value *V) {
if (Val) removeFromList();
Val = V;
if (V) V->addUse(*this);
}
template <class Compare> void Value::sortUseList(Compare Cmp) {
if (!UseList || !UseList->Next)
// No need to sort 0 or 1 uses.
return;
// Note: this function completely ignores Prev pointers until the end when
// they're fixed en masse.
// Create a binomial vector of sorted lists, visiting uses one at a time and
// merging lists as necessary.
const unsigned MaxSlots = 32;
Use *Slots[MaxSlots];
// Collect the first use, turning it into a single-item list.
Use *Next = UseList->Next;
UseList->Next = nullptr;
unsigned NumSlots = 1;
Slots[0] = UseList;
// Collect all but the last use.
while (Next->Next) {
Use *Current = Next;
Next = Current->Next;
// Turn Current into a single-item list.
Current->Next = nullptr;
// Save Current in the first available slot, merging on collisions.
unsigned I;
for (I = 0; I < NumSlots; ++I) {
if (!Slots[I])
break;
// Merge two lists, doubling the size of Current and emptying slot I.
//
// Since the uses in Slots[I] originally preceded those in Current, send
// Slots[I] in as the left parameter to maintain a stable sort.
Current = mergeUseLists(Slots[I], Current, Cmp);
Slots[I] = nullptr;
}
// Check if this is a new slot.
if (I == NumSlots) {
++NumSlots;
assert(NumSlots <= MaxSlots && "Use list bigger than 2^32");
}
// Found an open slot.
Slots[I] = Current;
}
// Merge all the lists together.
assert(Next && "Expected one more Use");
assert(!Next->Next && "Expected only one Use");
UseList = Next;
for (unsigned I = 0; I < NumSlots; ++I)
if (Slots[I])
// Since the uses in Slots[I] originally preceded those in UseList, send
// Slots[I] in as the left parameter to maintain a stable sort.
UseList = mergeUseLists(Slots[I], UseList, Cmp);
// Fix the Prev pointers.
for (Use *I = UseList, **Prev = &UseList; I; I = I->Next) {
I->setPrev(Prev);
Prev = &I->Next;
}
}
template <class Compare>
void Value::mergeUseListsImpl(Use *L, Use *R, Use **Next, Compare Cmp) {
if (!L) {
*Next = R;
return;
}
if (!R) {
*Next = L;
return;
}
if (Cmp(*R, *L)) {
*Next = R;
mergeUseListsImpl(L, R->Next, &R->Next, Cmp);
return;
}
*Next = L;
mergeUseListsImpl(L->Next, R, &L->Next, Cmp);
}
// isa - Provide some specializations of isa so that we don't have to include
// the subtype header files to test to see if the value is a subclass...
//
template <> struct isa_impl<Constant, Value> {
static inline bool doit(const Value &Val) {
return Val.getValueID() >= Value::ConstantFirstVal &&
Val.getValueID() <= Value::ConstantLastVal;
}
};
template <> struct isa_impl<Argument, Value> {
static inline bool doit (const Value &Val) {
return Val.getValueID() == Value::ArgumentVal;
}
};
template <> struct isa_impl<InlineAsm, Value> {
static inline bool doit(const Value &Val) {
return Val.getValueID() == Value::InlineAsmVal;
}
};
template <> struct isa_impl<Instruction, Value> {
static inline bool doit(const Value &Val) {
return Val.getValueID() >= Value::InstructionVal;
}
};
template <> struct isa_impl<BasicBlock, Value> {
static inline bool doit(const Value &Val) {
return Val.getValueID() == Value::BasicBlockVal;
}
};
template <> struct isa_impl<Function, Value> {
static inline bool doit(const Value &Val) {
return Val.getValueID() == Value::FunctionVal;
}
};
template <> struct isa_impl<GlobalVariable, Value> {
static inline bool doit(const Value &Val) {
return Val.getValueID() == Value::GlobalVariableVal;
}
};
template <> struct isa_impl<GlobalAlias, Value> {
static inline bool doit(const Value &Val) {
return Val.getValueID() == Value::GlobalAliasVal;
}
};
template <> struct isa_impl<GlobalValue, Value> {
static inline bool doit(const Value &Val) {
return isa<GlobalObject>(Val) || isa<GlobalAlias>(Val);
}
};
template <> struct isa_impl<GlobalObject, Value> {
static inline bool doit(const Value &Val) {
return isa<GlobalVariable>(Val) || isa<Function>(Val);
}
};
// Value* is only 4-byte aligned.
template<>
class PointerLikeTypeTraits<Value*> {
typedef Value* PT;
public:
static inline void *getAsVoidPointer(PT P) { return P; }
static inline PT getFromVoidPointer(void *P) {
return static_cast<PT>(P);
}
enum { NumLowBitsAvailable = 2 };
};
// Create wrappers for C Binding types (see CBindingWrapping.h).
DEFINE_ISA_CONVERSION_FUNCTIONS(Value, LLVMValueRef)
/* Specialized opaque value conversions.
*/
inline Value **unwrap(LLVMValueRef *Vals) {
return reinterpret_cast<Value**>(Vals);
}
template<typename T>
inline T **unwrap(LLVMValueRef *Vals, unsigned Length) {
#ifdef DEBUG
for (LLVMValueRef *I = Vals, *E = Vals + Length; I != E; ++I)
cast<T>(*I);
#endif
(void)Length;
return reinterpret_cast<T**>(Vals);
}
inline LLVMValueRef *wrap(const Value **Vals) {
return reinterpret_cast<LLVMValueRef*>(const_cast<Value**>(Vals));
}
} // End llvm namespace
#endif