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//==- llvm/CodeGen/MachineMemOperand.h - MachineMemOperand 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 contains the declaration of the MachineMemOperand class, which is a
// description of a memory reference. It is used to help track dependencies
// in the backend.
#include "llvm/ADT/BitmaskEnum.h"
#include "llvm/ADT/PointerUnion.h"
#include "llvm/CodeGen/PseudoSourceValue.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/Metadata.h"
#include "llvm/IR/Value.h" // PointerLikeTypeTraits<Value*>
#include "llvm/Support/AtomicOrdering.h"
#include "llvm/Support/DataTypes.h"
namespace llvm {
class FoldingSetNodeID;
class MDNode;
class raw_ostream;
class MachineFunction;
class ModuleSlotTracker;
/// This class contains a discriminated union of information about pointers in
/// memory operands, relating them back to LLVM IR or to virtual locations (such
/// as frame indices) that are exposed during codegen.
struct MachinePointerInfo {
/// This is the IR pointer value for the access, or it is null if unknown.
/// If this is null, then the access is to a pointer in the default address
/// space.
PointerUnion<const Value *, const PseudoSourceValue *> V;
/// Offset - This is an offset from the base Value*.
int64_t Offset;
uint8_t StackID;
unsigned AddrSpace = 0;
explicit MachinePointerInfo(const Value *v, int64_t offset = 0,
uint8_t ID = 0)
: V(v), Offset(offset), StackID(ID) {
AddrSpace = v ? v->getType()->getPointerAddressSpace() : 0;
explicit MachinePointerInfo(const PseudoSourceValue *v, int64_t offset = 0,
uint8_t ID = 0)
: V(v), Offset(offset), StackID(ID) {
AddrSpace = v ? v->getAddressSpace() : 0;
explicit MachinePointerInfo(unsigned AddressSpace = 0)
: V((const Value *)nullptr), Offset(0), StackID(0),
AddrSpace(AddressSpace) {}
explicit MachinePointerInfo(
PointerUnion<const Value *, const PseudoSourceValue *> v,
int64_t offset = 0,
uint8_t ID = 0)
: V(v), Offset(offset), StackID(ID) {
if (V) {
if (const auto *ValPtr = V.dyn_cast<const Value*>())
AddrSpace = ValPtr->getType()->getPointerAddressSpace();
AddrSpace = V.get<const PseudoSourceValue*>()->getAddressSpace();
MachinePointerInfo getWithOffset(int64_t O) const {
if (V.isNull())
return MachinePointerInfo(AddrSpace);
if (<const Value*>())
return MachinePointerInfo(V.get<const Value*>(), Offset+O, StackID);
return MachinePointerInfo(V.get<const PseudoSourceValue*>(), Offset+O,
/// Return true if memory region [V, V+Offset+Size) is known to be
/// dereferenceable.
bool isDereferenceable(unsigned Size, LLVMContext &C,
const DataLayout &DL) const;
/// Return the LLVM IR address space number that this pointer points into.
unsigned getAddrSpace() const;
/// Return a MachinePointerInfo record that refers to the constant pool.
static MachinePointerInfo getConstantPool(MachineFunction &MF);
/// Return a MachinePointerInfo record that refers to the specified
/// FrameIndex.
static MachinePointerInfo getFixedStack(MachineFunction &MF, int FI,
int64_t Offset = 0);
/// Return a MachinePointerInfo record that refers to a jump table entry.
static MachinePointerInfo getJumpTable(MachineFunction &MF);
/// Return a MachinePointerInfo record that refers to a GOT entry.
static MachinePointerInfo getGOT(MachineFunction &MF);
/// Stack pointer relative access.
static MachinePointerInfo getStack(MachineFunction &MF, int64_t Offset,
uint8_t ID = 0);
/// Stack memory without other information.
static MachinePointerInfo getUnknownStack(MachineFunction &MF);
/// A description of a memory reference used in the backend.
/// Instead of holding a StoreInst or LoadInst, this class holds the address
/// Value of the reference along with a byte size and offset. This allows it
/// to describe lowered loads and stores. Also, the special PseudoSourceValue
/// objects can be used to represent loads and stores to memory locations
/// that aren't explicit in the regular LLVM IR.
class MachineMemOperand {
/// Flags values. These may be or'd together.
enum Flags : uint16_t {
// No flags set.
MONone = 0,
/// The memory access reads data.
MOLoad = 1u << 0,
/// The memory access writes data.
MOStore = 1u << 1,
/// The memory access is volatile.
MOVolatile = 1u << 2,
/// The memory access is non-temporal.
MONonTemporal = 1u << 3,
/// The memory access is dereferenceable (i.e., doesn't trap).
MODereferenceable = 1u << 4,
/// The memory access always returns the same value (or traps).
MOInvariant = 1u << 5,
// Reserved for use by target-specific passes.
// Targets may override getSerializableMachineMemOperandTargetFlags() to
// enable MIR serialization/parsing of these flags. If more of these flags
// are added, the MIR printing/parsing code will need to be updated as well.
MOTargetFlag1 = 1u << 6,
MOTargetFlag2 = 1u << 7,
MOTargetFlag3 = 1u << 8,
LLVM_MARK_AS_BITMASK_ENUM(/* LargestFlag = */ MOTargetFlag3)
/// Atomic information for this memory operation.
struct MachineAtomicInfo {
/// Synchronization scope ID for this memory operation.
unsigned SSID : 8; // SyncScope::ID
/// Atomic ordering requirements for this memory operation. For cmpxchg
/// atomic operations, atomic ordering requirements when store occurs.
unsigned Ordering : 4; // enum AtomicOrdering
/// For cmpxchg atomic operations, atomic ordering requirements when store
/// does not occur.
unsigned FailureOrdering : 4; // enum AtomicOrdering
MachinePointerInfo PtrInfo;
uint64_t Size;
Flags FlagVals;
uint16_t BaseAlignLog2; // log_2(base_alignment) + 1
MachineAtomicInfo AtomicInfo;
AAMDNodes AAInfo;
const MDNode *Ranges;
/// Construct a MachineMemOperand object with the specified PtrInfo, flags,
/// size, and base alignment. For atomic operations the synchronization scope
/// and atomic ordering requirements must also be specified. For cmpxchg
/// atomic operations the atomic ordering requirements when store does not
/// occur must also be specified.
MachineMemOperand(MachinePointerInfo PtrInfo, Flags flags, uint64_t s,
uint64_t a,
const AAMDNodes &AAInfo = AAMDNodes(),
const MDNode *Ranges = nullptr,
SyncScope::ID SSID = SyncScope::System,
AtomicOrdering Ordering = AtomicOrdering::NotAtomic,
AtomicOrdering FailureOrdering = AtomicOrdering::NotAtomic);
const MachinePointerInfo &getPointerInfo() const { return PtrInfo; }
/// Return the base address of the memory access. This may either be a normal
/// LLVM IR Value, or one of the special values used in CodeGen.
/// Special values are those obtained via
/// PseudoSourceValue::getFixedStack(int), PseudoSourceValue::getStack, and
/// other PseudoSourceValue member functions which return objects which stand
/// for frame/stack pointer relative references and other special references
/// which are not representable in the high-level IR.
const Value *getValue() const { return PtrInfo.V.dyn_cast<const Value*>(); }
const PseudoSourceValue *getPseudoValue() const {
return PtrInfo.V.dyn_cast<const PseudoSourceValue*>();
const void *getOpaqueValue() const { return PtrInfo.V.getOpaqueValue(); }
/// Return the raw flags of the source value, \see Flags.
Flags getFlags() const { return FlagVals; }
/// Bitwise OR the current flags with the given flags.
void setFlags(Flags f) { FlagVals |= f; }
/// For normal values, this is a byte offset added to the base address.
/// For PseudoSourceValue::FPRel values, this is the FrameIndex number.
int64_t getOffset() const { return PtrInfo.Offset; }
unsigned getAddrSpace() const { return PtrInfo.getAddrSpace(); }
/// Return the size in bytes of the memory reference.
uint64_t getSize() const { return Size; }
/// Return the minimum known alignment in bytes of the actual memory
/// reference.
uint64_t getAlignment() const;
/// Return the minimum known alignment in bytes of the base address, without
/// the offset.
uint64_t getBaseAlignment() const { return (1u << BaseAlignLog2) >> 1; }
/// Return the AA tags for the memory reference.
AAMDNodes getAAInfo() const { return AAInfo; }
/// Return the range tag for the memory reference.
const MDNode *getRanges() const { return Ranges; }
/// Returns the synchronization scope ID for this memory operation.
SyncScope::ID getSyncScopeID() const {
return static_cast<SyncScope::ID>(AtomicInfo.SSID);
/// Return the atomic ordering requirements for this memory operation. For
/// cmpxchg atomic operations, return the atomic ordering requirements when
/// store occurs.
AtomicOrdering getOrdering() const {
return static_cast<AtomicOrdering>(AtomicInfo.Ordering);
/// For cmpxchg atomic operations, return the atomic ordering requirements
/// when store does not occur.
AtomicOrdering getFailureOrdering() const {
return static_cast<AtomicOrdering>(AtomicInfo.FailureOrdering);
bool isLoad() const { return FlagVals & MOLoad; }
bool isStore() const { return FlagVals & MOStore; }
bool isVolatile() const { return FlagVals & MOVolatile; }
bool isNonTemporal() const { return FlagVals & MONonTemporal; }
bool isDereferenceable() const { return FlagVals & MODereferenceable; }
bool isInvariant() const { return FlagVals & MOInvariant; }
/// Returns true if this operation has an atomic ordering requirement of
/// unordered or higher, false otherwise.
bool isAtomic() const { return getOrdering() != AtomicOrdering::NotAtomic; }
/// Returns true if this memory operation doesn't have any ordering
/// constraints other than normal aliasing. Volatile and atomic memory
/// operations can't be reordered.
/// Currently, we don't model the difference between volatile and atomic
/// operations. They should retain their ordering relative to all memory
/// operations.
bool isUnordered() const { return !isVolatile(); }
/// Update this MachineMemOperand to reflect the alignment of MMO, if it has a
/// greater alignment. This must only be used when the new alignment applies
/// to all users of this MachineMemOperand.
void refineAlignment(const MachineMemOperand *MMO);
/// Change the SourceValue for this MachineMemOperand. This should only be
/// used when an object is being relocated and all references to it are being
/// updated.
void setValue(const Value *NewSV) { PtrInfo.V = NewSV; }
void setValue(const PseudoSourceValue *NewSV) { PtrInfo.V = NewSV; }
void setOffset(int64_t NewOffset) { PtrInfo.Offset = NewOffset; }
/// Profile - Gather unique data for the object.
void Profile(FoldingSetNodeID &ID) const;
/// Support for operator<<.
/// @{
void print(raw_ostream &OS) const;
void print(raw_ostream &OS, ModuleSlotTracker &MST) const;
void print(raw_ostream &OS, ModuleSlotTracker &MST,
SmallVectorImpl<StringRef> &SSNs, const LLVMContext &Context,
const MachineFrameInfo *MFI, const TargetInstrInfo *TII) const;
/// @}
friend bool operator==(const MachineMemOperand &LHS,
const MachineMemOperand &RHS) {
return LHS.getValue() == RHS.getValue() &&
LHS.getPseudoValue() == RHS.getPseudoValue() &&
LHS.getSize() == RHS.getSize() &&
LHS.getOffset() == RHS.getOffset() &&
LHS.getFlags() == RHS.getFlags() &&
LHS.getAAInfo() == RHS.getAAInfo() &&
LHS.getRanges() == RHS.getRanges() &&
LHS.getAlignment() == RHS.getAlignment() &&
LHS.getAddrSpace() == RHS.getAddrSpace();
friend bool operator!=(const MachineMemOperand &LHS,
const MachineMemOperand &RHS) {
return !(LHS == RHS);
inline raw_ostream &operator<<(raw_ostream &OS, const MachineMemOperand &MRO) {
return OS;
} // End llvm namespace