blob: c15ee1c006cda12c73aa59bb221c44769084a2c4 [file] [log] [blame]
//===-- llvm/CodeGen/MachineFunction.h --------------------------*- C++ -*-===//
// The LLVM Compiler Infrastructure
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
// Collect native machine code for a function. This class contains a list of
// MachineBasicBlock instances that make up the current compiled function.
// This class also contains pointers to various classes which hold
// target-specific information about the generated code.
#include "llvm/ADT/ilist.h"
#include "llvm/CodeGen/MachineBasicBlock.h"
#include "llvm/IR/DebugLoc.h"
#include "llvm/IR/Metadata.h"
#include "llvm/Support/Allocator.h"
#include "llvm/Support/ArrayRecycler.h"
#include "llvm/Support/Recycler.h"
namespace llvm {
class Value;
class Function;
class GCModuleInfo;
class MachineRegisterInfo;
class MachineFrameInfo;
class MachineConstantPool;
class MachineJumpTableInfo;
class MachineModuleInfo;
class MCContext;
class Pass;
class TargetMachine;
class TargetSubtargetInfo;
class TargetRegisterClass;
struct MachinePointerInfo;
template <>
struct ilist_traits<MachineBasicBlock>
: public ilist_default_traits<MachineBasicBlock> {
mutable ilist_half_node<MachineBasicBlock> Sentinel;
MachineBasicBlock *createSentinel() const {
return static_cast<MachineBasicBlock*>(&Sentinel);
void destroySentinel(MachineBasicBlock *) const {}
MachineBasicBlock *provideInitialHead() const { return createSentinel(); }
MachineBasicBlock *ensureHead(MachineBasicBlock*) const {
return createSentinel();
static void noteHead(MachineBasicBlock*, MachineBasicBlock*) {}
void addNodeToList(MachineBasicBlock* MBB);
void removeNodeFromList(MachineBasicBlock* MBB);
void deleteNode(MachineBasicBlock *MBB);
void createNode(const MachineBasicBlock &);
/// MachineFunctionInfo - This class can be derived from and used by targets to
/// hold private target-specific information for each MachineFunction. Objects
/// of type are accessed/created with MF::getInfo and destroyed when the
/// MachineFunction is destroyed.
struct MachineFunctionInfo {
virtual ~MachineFunctionInfo();
/// \brief Factory function: default behavior is to call new using the
/// supplied allocator.
/// This function can be overridden in a derive class.
template<typename Ty>
static Ty *create(BumpPtrAllocator &Allocator, MachineFunction &MF) {
return new (Allocator.Allocate<Ty>()) Ty(MF);
class MachineFunction {
const Function *Fn;
const TargetMachine &Target;
const TargetSubtargetInfo *STI;
MCContext &Ctx;
MachineModuleInfo &MMI;
// RegInfo - Information about each register in use in the function.
MachineRegisterInfo *RegInfo;
// Used to keep track of target-specific per-machine function information for
// the target implementation.
MachineFunctionInfo *MFInfo;
// Keep track of objects allocated on the stack.
MachineFrameInfo *FrameInfo;
// Keep track of constants which are spilled to memory
MachineConstantPool *ConstantPool;
// Keep track of jump tables for switch instructions
MachineJumpTableInfo *JumpTableInfo;
// Function-level unique numbering for MachineBasicBlocks. When a
// MachineBasicBlock is inserted into a MachineFunction is it automatically
// numbered and this vector keeps track of the mapping from ID's to MBB's.
std::vector<MachineBasicBlock*> MBBNumbering;
// Pool-allocate MachineFunction-lifetime and IR objects.
BumpPtrAllocator Allocator;
// Allocation management for instructions in function.
Recycler<MachineInstr> InstructionRecycler;
// Allocation management for operand arrays on instructions.
ArrayRecycler<MachineOperand> OperandRecycler;
// Allocation management for basic blocks in function.
Recycler<MachineBasicBlock> BasicBlockRecycler;
// List of machine basic blocks in function
typedef ilist<MachineBasicBlock> BasicBlockListType;
BasicBlockListType BasicBlocks;
/// FunctionNumber - This provides a unique ID for each function emitted in
/// this translation unit.
unsigned FunctionNumber;
/// Alignment - The alignment of the function.
unsigned Alignment;
/// ExposesReturnsTwice - True if the function calls setjmp or related
/// functions with attribute "returns twice", but doesn't have
/// the attribute itself.
/// This is used to limit optimizations which cannot reason
/// about the control flow of such functions.
bool ExposesReturnsTwice;
/// True if the function includes any inline assembly.
bool HasInlineAsm;
MachineFunction(const MachineFunction &) = delete;
void operator=(const MachineFunction&) = delete;
MachineFunction(const Function *Fn, const TargetMachine &TM,
unsigned FunctionNum, MachineModuleInfo &MMI);
MachineModuleInfo &getMMI() const { return MMI; }
MCContext &getContext() const { return Ctx; }
/// Return the DataLayout attached to the Module associated to this MF.
const DataLayout &getDataLayout() const;
/// getFunction - Return the LLVM function that this machine code represents
const Function *getFunction() const { return Fn; }
/// getName - Return the name of the corresponding LLVM function.
StringRef getName() const;
/// getFunctionNumber - Return a unique ID for the current function.
unsigned getFunctionNumber() const { return FunctionNumber; }
/// getTarget - Return the target machine this machine code is compiled with
const TargetMachine &getTarget() const { return Target; }
/// getSubtarget - Return the subtarget for which this machine code is being
/// compiled.
const TargetSubtargetInfo &getSubtarget() const { return *STI; }
void setSubtarget(const TargetSubtargetInfo *ST) { STI = ST; }
/// getSubtarget - This method returns a pointer to the specified type of
/// TargetSubtargetInfo. In debug builds, it verifies that the object being
/// returned is of the correct type.
template<typename STC> const STC &getSubtarget() const {
return *static_cast<const STC *>(STI);
/// getRegInfo - Return information about the registers currently in use.
MachineRegisterInfo &getRegInfo() { return *RegInfo; }
const MachineRegisterInfo &getRegInfo() const { return *RegInfo; }
/// getFrameInfo - Return the frame info object for the current function.
/// This object contains information about objects allocated on the stack
/// frame of the current function in an abstract way.
MachineFrameInfo *getFrameInfo() { return FrameInfo; }
const MachineFrameInfo *getFrameInfo() const { return FrameInfo; }
/// getJumpTableInfo - Return the jump table info object for the current
/// function. This object contains information about jump tables in the
/// current function. If the current function has no jump tables, this will
/// return null.
const MachineJumpTableInfo *getJumpTableInfo() const { return JumpTableInfo; }
MachineJumpTableInfo *getJumpTableInfo() { return JumpTableInfo; }
/// getOrCreateJumpTableInfo - Get the JumpTableInfo for this function, if it
/// does already exist, allocate one.
MachineJumpTableInfo *getOrCreateJumpTableInfo(unsigned JTEntryKind);
/// getConstantPool - Return the constant pool object for the current
/// function.
MachineConstantPool *getConstantPool() { return ConstantPool; }
const MachineConstantPool *getConstantPool() const { return ConstantPool; }
/// getAlignment - Return the alignment (log2, not bytes) of the function.
unsigned getAlignment() const { return Alignment; }
/// setAlignment - Set the alignment (log2, not bytes) of the function.
void setAlignment(unsigned A) { Alignment = A; }
/// ensureAlignment - Make sure the function is at least 1 << A bytes aligned.
void ensureAlignment(unsigned A) {
if (Alignment < A) Alignment = A;
/// exposesReturnsTwice - Returns true if the function calls setjmp or
/// any other similar functions with attribute "returns twice" without
/// having the attribute itself.
bool exposesReturnsTwice() const {
return ExposesReturnsTwice;
/// setCallsSetJmp - Set a flag that indicates if there's a call to
/// a "returns twice" function.
void setExposesReturnsTwice(bool B) {
ExposesReturnsTwice = B;
/// Returns true if the function contains any inline assembly.
bool hasInlineAsm() const {
return HasInlineAsm;
/// Set a flag that indicates that the function contains inline assembly.
void setHasInlineAsm(bool B) {
HasInlineAsm = B;
/// getInfo - Keep track of various per-function pieces of information for
/// backends that would like to do so.
template<typename Ty>
Ty *getInfo() {
if (!MFInfo)
MFInfo = Ty::template create<Ty>(Allocator, *this);
return static_cast<Ty*>(MFInfo);
template<typename Ty>
const Ty *getInfo() const {
return const_cast<MachineFunction*>(this)->getInfo<Ty>();
/// getBlockNumbered - MachineBasicBlocks are automatically numbered when they
/// are inserted into the machine function. The block number for a machine
/// basic block can be found by using the MBB::getBlockNumber method, this
/// method provides the inverse mapping.
MachineBasicBlock *getBlockNumbered(unsigned N) const {
assert(N < MBBNumbering.size() && "Illegal block number");
assert(MBBNumbering[N] && "Block was removed from the machine function!");
return MBBNumbering[N];
/// Should we be emitting segmented stack stuff for the function
bool shouldSplitStack();
/// getNumBlockIDs - Return the number of MBB ID's allocated.
unsigned getNumBlockIDs() const { return (unsigned)MBBNumbering.size(); }
/// RenumberBlocks - This discards all of the MachineBasicBlock numbers and
/// recomputes them. This guarantees that the MBB numbers are sequential,
/// dense, and match the ordering of the blocks within the function. If a
/// specific MachineBasicBlock is specified, only that block and those after
/// it are renumbered.
void RenumberBlocks(MachineBasicBlock *MBBFrom = nullptr);
/// print - Print out the MachineFunction in a format suitable for debugging
/// to the specified stream.
void print(raw_ostream &OS, SlotIndexes* = nullptr) const;
/// viewCFG - This function is meant for use from the debugger. You can just
/// say 'call F->viewCFG()' and a ghostview window should pop up from the
/// program, displaying the CFG of the current function with the code for each
/// basic block inside. This depends on there being a 'dot' and 'gv' program
/// in your path.
void viewCFG() const;
/// viewCFGOnly - This function is meant for use from the debugger. It works
/// just like viewCFG, but it does not include the contents of basic blocks
/// into the nodes, just the label. If you are only interested in the CFG
/// this can make the graph smaller.
void viewCFGOnly() const;
/// dump - Print the current MachineFunction to cerr, useful for debugger use.
void dump() const;
/// verify - Run the current MachineFunction through the machine code
/// verifier, useful for debugger use.
void verify(Pass *p = nullptr, const char *Banner = nullptr) const;
// Provide accessors for the MachineBasicBlock list...
typedef BasicBlockListType::iterator iterator;
typedef BasicBlockListType::const_iterator const_iterator;
typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
typedef std::reverse_iterator<iterator> reverse_iterator;
/// addLiveIn - Add the specified physical register as a live-in value and
/// create a corresponding virtual register for it.
unsigned addLiveIn(unsigned PReg, const TargetRegisterClass *RC);
// BasicBlock accessor functions.
iterator begin() { return BasicBlocks.begin(); }
const_iterator begin() const { return BasicBlocks.begin(); }
iterator end () { return BasicBlocks.end(); }
const_iterator end () const { return BasicBlocks.end(); }
reverse_iterator rbegin() { return BasicBlocks.rbegin(); }
const_reverse_iterator rbegin() const { return BasicBlocks.rbegin(); }
reverse_iterator rend () { return BasicBlocks.rend(); }
const_reverse_iterator rend () const { return BasicBlocks.rend(); }
unsigned size() const { return (unsigned)BasicBlocks.size();}
bool empty() const { return BasicBlocks.empty(); }
const MachineBasicBlock &front() const { return BasicBlocks.front(); }
MachineBasicBlock &front() { return BasicBlocks.front(); }
const MachineBasicBlock & back() const { return BasicBlocks.back(); }
MachineBasicBlock & back() { return BasicBlocks.back(); }
void push_back (MachineBasicBlock *MBB) { BasicBlocks.push_back (MBB); }
void push_front(MachineBasicBlock *MBB) { BasicBlocks.push_front(MBB); }
void insert(iterator MBBI, MachineBasicBlock *MBB) {
BasicBlocks.insert(MBBI, MBB);
void splice(iterator InsertPt, iterator MBBI) {
BasicBlocks.splice(InsertPt, BasicBlocks, MBBI);
void splice(iterator InsertPt, iterator MBBI, iterator MBBE) {
BasicBlocks.splice(InsertPt, BasicBlocks, MBBI, MBBE);
void remove(iterator MBBI) {
void erase(iterator MBBI) {
// Internal functions used to automatically number MachineBasicBlocks
/// \brief Adds the MBB to the internal numbering. Returns the unique number
/// assigned to the MBB.
unsigned addToMBBNumbering(MachineBasicBlock *MBB) {
return (unsigned)MBBNumbering.size()-1;
/// removeFromMBBNumbering - Remove the specific machine basic block from our
/// tracker, this is only really to be used by the MachineBasicBlock
/// implementation.
void removeFromMBBNumbering(unsigned N) {
assert(N < MBBNumbering.size() && "Illegal basic block #");
MBBNumbering[N] = nullptr;
/// CreateMachineInstr - Allocate a new MachineInstr. Use this instead
/// of `new MachineInstr'.
MachineInstr *CreateMachineInstr(const MCInstrDesc &MCID,
DebugLoc DL,
bool NoImp = false);
/// CloneMachineInstr - Create a new MachineInstr which is a copy of the
/// 'Orig' instruction, identical in all ways except the instruction
/// has no parent, prev, or next.
/// See also TargetInstrInfo::duplicate() for target-specific fixes to cloned
/// instructions.
MachineInstr *CloneMachineInstr(const MachineInstr *Orig);
/// DeleteMachineInstr - Delete the given MachineInstr.
void DeleteMachineInstr(MachineInstr *MI);
/// CreateMachineBasicBlock - Allocate a new MachineBasicBlock. Use this
/// instead of `new MachineBasicBlock'.
MachineBasicBlock *CreateMachineBasicBlock(const BasicBlock *bb = nullptr);
/// DeleteMachineBasicBlock - Delete the given MachineBasicBlock.
void DeleteMachineBasicBlock(MachineBasicBlock *MBB);
/// getMachineMemOperand - Allocate a new MachineMemOperand.
/// MachineMemOperands are owned by the MachineFunction and need not be
/// explicitly deallocated.
MachineMemOperand *getMachineMemOperand(MachinePointerInfo PtrInfo,
unsigned f, uint64_t s,
unsigned base_alignment,
const AAMDNodes &AAInfo = AAMDNodes(),
const MDNode *Ranges = nullptr);
/// getMachineMemOperand - Allocate a new MachineMemOperand by copying
/// an existing one, adjusting by an offset and using the given size.
/// MachineMemOperands are owned by the MachineFunction and need not be
/// explicitly deallocated.
MachineMemOperand *getMachineMemOperand(const MachineMemOperand *MMO,
int64_t Offset, uint64_t Size);
typedef ArrayRecycler<MachineOperand>::Capacity OperandCapacity;
/// Allocate an array of MachineOperands. This is only intended for use by
/// internal MachineInstr functions.
MachineOperand *allocateOperandArray(OperandCapacity Cap) {
return OperandRecycler.allocate(Cap, Allocator);
/// Dellocate an array of MachineOperands and recycle the memory. This is
/// only intended for use by internal MachineInstr functions.
/// Cap must be the same capacity that was used to allocate the array.
void deallocateOperandArray(OperandCapacity Cap, MachineOperand *Array) {
OperandRecycler.deallocate(Cap, Array);
/// \brief Allocate and initialize a register mask with @p NumRegister bits.
uint32_t *allocateRegisterMask(unsigned NumRegister) {
unsigned Size = (NumRegister + 31) / 32;
uint32_t *Mask = Allocator.Allocate<uint32_t>(Size);
for (unsigned i = 0; i != Size; ++i)
Mask[i] = 0;
return Mask;
/// allocateMemRefsArray - Allocate an array to hold MachineMemOperand
/// pointers. This array is owned by the MachineFunction.
MachineInstr::mmo_iterator allocateMemRefsArray(unsigned long Num);
/// extractLoadMemRefs - Allocate an array and populate it with just the
/// load information from the given MachineMemOperand sequence.
extractLoadMemRefs(MachineInstr::mmo_iterator Begin,
MachineInstr::mmo_iterator End);
/// extractStoreMemRefs - Allocate an array and populate it with just the
/// store information from the given MachineMemOperand sequence.
extractStoreMemRefs(MachineInstr::mmo_iterator Begin,
MachineInstr::mmo_iterator End);
// Label Manipulation.
/// getJTISymbol - Return the MCSymbol for the specified non-empty jump table.
/// If isLinkerPrivate is specified, an 'l' label is returned, otherwise a
/// normal 'L' label is returned.
MCSymbol *getJTISymbol(unsigned JTI, MCContext &Ctx,
bool isLinkerPrivate = false) const;
/// getPICBaseSymbol - Return a function-local symbol to represent the PIC
/// base.
MCSymbol *getPICBaseSymbol() const;
// GraphTraits specializations for function basic block graphs (CFGs)
// Provide specializations of GraphTraits to be able to treat a
// machine function as a graph of machine basic blocks... these are
// the same as the machine basic block iterators, except that the root
// node is implicitly the first node of the function.
template <> struct GraphTraits<MachineFunction*> :
public GraphTraits<MachineBasicBlock*> {
static NodeType *getEntryNode(MachineFunction *F) {
return &F->front();
// nodes_iterator/begin/end - Allow iteration over all nodes in the graph
typedef MachineFunction::iterator nodes_iterator;
static nodes_iterator nodes_begin(MachineFunction *F) { return F->begin(); }
static nodes_iterator nodes_end (MachineFunction *F) { return F->end(); }
static unsigned size (MachineFunction *F) { return F->size(); }
template <> struct GraphTraits<const MachineFunction*> :
public GraphTraits<const MachineBasicBlock*> {
static NodeType *getEntryNode(const MachineFunction *F) {
return &F->front();
// nodes_iterator/begin/end - Allow iteration over all nodes in the graph
typedef MachineFunction::const_iterator nodes_iterator;
static nodes_iterator nodes_begin(const MachineFunction *F) {
return F->begin();
static nodes_iterator nodes_end (const MachineFunction *F) {
return F->end();
static unsigned size (const MachineFunction *F) {
return F->size();
// Provide specializations of GraphTraits to be able to treat a function as a
// graph of basic blocks... and to walk it in inverse order. Inverse order for
// a function is considered to be when traversing the predecessor edges of a BB
// instead of the successor edges.
template <> struct GraphTraits<Inverse<MachineFunction*> > :
public GraphTraits<Inverse<MachineBasicBlock*> > {
static NodeType *getEntryNode(Inverse<MachineFunction*> G) {
return &G.Graph->front();
template <> struct GraphTraits<Inverse<const MachineFunction*> > :
public GraphTraits<Inverse<const MachineBasicBlock*> > {
static NodeType *getEntryNode(Inverse<const MachineFunction *> G) {
return &G.Graph->front();
} // End llvm namespace