//===- llvm/CodeGen/MachineInstr.h - MachineInstr class ---------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file contains the declaration of the MachineInstr class, which is the
// basic representation for all target dependent machine instructions used by
// the back end.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_CODEGEN_MACHINEINSTR_H
#define LLVM_CODEGEN_MACHINEINSTR_H
#include "llvm/ADT/DenseMapInfo.h"
#include "llvm/ADT/PointerSumType.h"
#include "llvm/ADT/SmallSet.h"
#include "llvm/ADT/ilist.h"
#include "llvm/ADT/ilist_node.h"
#include "llvm/ADT/iterator_range.h"
#include "llvm/CodeGen/MachineMemOperand.h"
#include "llvm/CodeGen/MachineOperand.h"
#include "llvm/CodeGen/TargetOpcodes.h"
#include "llvm/IR/DebugLoc.h"
#include "llvm/IR/InlineAsm.h"
#include "llvm/MC/MCInstrDesc.h"
#include "llvm/MC/MCSymbol.h"
#include "llvm/Support/ArrayRecycler.h"
#include "llvm/Support/TrailingObjects.h"
#include <algorithm>
#include <cassert>
#include <cstdint>
#include <utility>
namespace llvm {
class DILabel;
class Instruction;
class MDNode;
class AAResults;
template <typename T> class ArrayRef;
class DIExpression;
class DILocalVariable;
class MachineBasicBlock;
class MachineFunction;
class MachineRegisterInfo;
class ModuleSlotTracker;
class raw_ostream;
template <typename T> class SmallVectorImpl;
class SmallBitVector;
class StringRef;
class TargetInstrInfo;
class TargetRegisterClass;
class TargetRegisterInfo;
//===----------------------------------------------------------------------===//
/// Representation of each machine instruction.
///
/// This class isn't a POD type, but it must have a trivial destructor. When a
/// MachineFunction is deleted, all the contained MachineInstrs are deallocated
/// without having their destructor called.
///
class MachineInstr
: public ilist_node_with_parent<MachineInstr, MachineBasicBlock,
ilist_sentinel_tracking<true>> {
public:
using mmo_iterator = ArrayRef<MachineMemOperand *>::iterator;
/// Flags to specify different kinds of comments to output in
/// assembly code. These flags carry semantic information not
/// otherwise easily derivable from the IR text.
///
enum CommentFlag {
ReloadReuse = 0x1, // higher bits are reserved for target dep comments.
NoSchedComment = 0x2,
TAsmComments = 0x4 // Target Asm comments should start from this value.
};
enum MIFlag {
NoFlags = 0,
FrameSetup = 1 << 0, // Instruction is used as a part of
// function frame setup code.
FrameDestroy = 1 << 1, // Instruction is used as a part of
// function frame destruction code.
BundledPred = 1 << 2, // Instruction has bundled predecessors.
BundledSucc = 1 << 3, // Instruction has bundled successors.
FmNoNans = 1 << 4, // Instruction does not support Fast
// math nan values.
FmNoInfs = 1 << 5, // Instruction does not support Fast
// math infinity values.
FmNsz = 1 << 6, // Instruction is not required to retain
// signed zero values.
FmArcp = 1 << 7, // Instruction supports Fast math
// reciprocal approximations.
FmContract = 1 << 8, // Instruction supports Fast math
// contraction operations like fma.
FmAfn = 1 << 9, // Instruction may map to Fast math
// intrinsic approximation.
FmReassoc = 1 << 10, // Instruction supports Fast math
// reassociation of operand order.
NoUWrap = 1 << 11, // Instruction supports binary operator
// no unsigned wrap.
NoSWrap = 1 << 12, // Instruction supports binary operator
// no signed wrap.
IsExact = 1 << 13, // Instruction supports division is
// known to be exact.
NoFPExcept = 1 << 14, // Instruction does not raise
// floatint-point exceptions.
NoMerge = 1 << 15, // Passes that drop source location info
// (e.g. branch folding) should skip
// this instruction.
};
private:
const MCInstrDesc *MCID; // Instruction descriptor.
MachineBasicBlock *Parent = nullptr; // Pointer to the owning basic block.
// Operands are allocated by an ArrayRecycler.
MachineOperand *Operands = nullptr; // Pointer to the first operand.
unsigned NumOperands = 0; // Number of operands on instruction.
uint16_t Flags = 0; // Various bits of additional
// information about machine
// instruction.
uint8_t AsmPrinterFlags = 0; // Various bits of information used by
// the AsmPrinter to emit helpful
// comments. This is *not* semantic
// information. Do not use this for
// anything other than to convey comment
// information to AsmPrinter.
// OperandCapacity has uint8_t size, so it should be next to AsmPrinterFlags
// to properly pack.
using OperandCapacity = ArrayRecycler<MachineOperand>::Capacity;
OperandCapacity CapOperands; // Capacity of the Operands array.
/// Internal implementation detail class that provides out-of-line storage for
/// extra info used by the machine instruction when this info cannot be stored
/// in-line within the instruction itself.
///
/// This has to be defined eagerly due to the implementation constraints of
/// `PointerSumType` where it is used.
class ExtraInfo final : TrailingObjects<ExtraInfo, MachineMemOperand *,
MCSymbol *, MDNode *, uint32_t> {
public:
static ExtraInfo *create(BumpPtrAllocator &Allocator,
ArrayRef<MachineMemOperand *> MMOs,
MCSymbol *PreInstrSymbol = nullptr,
MCSymbol *PostInstrSymbol = nullptr,
MDNode *HeapAllocMarker = nullptr,
MDNode *PCSections = nullptr,
uint32_t CFIType = 0) {
bool HasPreInstrSymbol = PreInstrSymbol != nullptr;
bool HasPostInstrSymbol = PostInstrSymbol != nullptr;
bool HasHeapAllocMarker = HeapAllocMarker != nullptr;
bool HasCFIType = CFIType != 0;
bool HasPCSections = PCSections != nullptr;
auto *Result = new (Allocator.Allocate(
totalSizeToAlloc<MachineMemOperand *, MCSymbol *, MDNode *, uint32_t>(
MMOs.size(), HasPreInstrSymbol + HasPostInstrSymbol,
HasHeapAllocMarker + HasPCSections, HasCFIType),
alignof(ExtraInfo)))
ExtraInfo(MMOs.size(), HasPreInstrSymbol, HasPostInstrSymbol,
HasHeapAllocMarker, HasPCSections, HasCFIType);
// Copy the actual data into the trailing objects.
std::copy(MMOs.begin(), MMOs.end(),
Result->getTrailingObjects<MachineMemOperand *>());
if (HasPreInstrSymbol)
Result->getTrailingObjects<MCSymbol *>()[0] = PreInstrSymbol;
if (HasPostInstrSymbol)
Result->getTrailingObjects<MCSymbol *>()[HasPreInstrSymbol] =
PostInstrSymbol;
if (HasHeapAllocMarker)
Result->getTrailingObjects<MDNode *>()[0] = HeapAllocMarker;
if (HasPCSections)
Result->getTrailingObjects<MDNode *>()[HasHeapAllocMarker] =
PCSections;
if (HasCFIType)
Result->getTrailingObjects<uint32_t>()[0] = CFIType;
return Result;
}
ArrayRef<MachineMemOperand *> getMMOs() const {
return ArrayRef(getTrailingObjects<MachineMemOperand *>(), NumMMOs);
}
MCSymbol *getPreInstrSymbol() const {
return HasPreInstrSymbol ? getTrailingObjects<MCSymbol *>()[0] : nullptr;
}
MCSymbol *getPostInstrSymbol() const {
return HasPostInstrSymbol
? getTrailingObjects<MCSymbol *>()[HasPreInstrSymbol]
: nullptr;
}
MDNode *getHeapAllocMarker() const {
return HasHeapAllocMarker ? getTrailingObjects<MDNode *>()[0] : nullptr;
}
MDNode *getPCSections() const {
return HasPCSections
? getTrailingObjects<MDNode *>()[HasHeapAllocMarker]
: nullptr;
}
uint32_t getCFIType() const {
return HasCFIType ? getTrailingObjects<uint32_t>()[0] : 0;
}
private:
friend TrailingObjects;
// Description of the extra info, used to interpret the actual optional
// data appended.
//
// Note that this is not terribly space optimized. This leaves a great deal
// of flexibility to fit more in here later.
const int NumMMOs;
const bool HasPreInstrSymbol;
const bool HasPostInstrSymbol;
const bool HasHeapAllocMarker;
const bool HasPCSections;
const bool HasCFIType;
// Implement the `TrailingObjects` internal API.
size_t numTrailingObjects(OverloadToken<MachineMemOperand *>) const {
return NumMMOs;
}
size_t numTrailingObjects(OverloadToken<MCSymbol *>) const {
return HasPreInstrSymbol + HasPostInstrSymbol;
}
size_t numTrailingObjects(OverloadToken<MDNode *>) const {
return HasHeapAllocMarker + HasPCSections;
}
size_t numTrailingObjects(OverloadToken<uint32_t>) const {
return HasCFIType;
}
// Just a boring constructor to allow us to initialize the sizes. Always use
// the `create` routine above.
ExtraInfo(int NumMMOs, bool HasPreInstrSymbol, bool HasPostInstrSymbol,
bool HasHeapAllocMarker, bool HasPCSections, bool HasCFIType)
: NumMMOs(NumMMOs), HasPreInstrSymbol(HasPreInstrSymbol),
HasPostInstrSymbol(HasPostInstrSymbol),
HasHeapAllocMarker(HasHeapAllocMarker), HasPCSections(HasPCSections),
HasCFIType(HasCFIType) {}
};
/// Enumeration of the kinds of inline extra info available. It is important
/// that the `MachineMemOperand` inline kind has a tag value of zero to make
/// it accessible as an `ArrayRef`.
enum ExtraInfoInlineKinds {
EIIK_MMO = 0,
EIIK_PreInstrSymbol,
EIIK_PostInstrSymbol,
EIIK_OutOfLine
};
// We store extra information about the instruction here. The common case is
// expected to be nothing or a single pointer (typically a MMO or a symbol).
// We work to optimize this common case by storing it inline here rather than
// requiring a separate allocation, but we fall back to an allocation when
// multiple pointers are needed.
PointerSumType<ExtraInfoInlineKinds,
PointerSumTypeMember<EIIK_MMO, MachineMemOperand *>,
PointerSumTypeMember<EIIK_PreInstrSymbol, MCSymbol *>,
PointerSumTypeMember<EIIK_PostInstrSymbol, MCSymbol *>,
PointerSumTypeMember<EIIK_OutOfLine, ExtraInfo *>>
Info;
DebugLoc DbgLoc; // Source line information.
/// Unique instruction number. Used by DBG_INSTR_REFs to refer to the values
/// defined by this instruction.
unsigned DebugInstrNum;
// Intrusive list support
friend struct ilist_traits<MachineInstr>;
friend struct ilist_callback_traits<MachineBasicBlock>;
void setParent(MachineBasicBlock *P) { Parent = P; }
/// This constructor creates a copy of the given
/// MachineInstr in the given MachineFunction.
MachineInstr(MachineFunction &, const MachineInstr &);
/// This constructor create a MachineInstr and add the implicit operands.
/// It reserves space for number of operands specified by
/// MCInstrDesc. An explicit DebugLoc is supplied.
MachineInstr(MachineFunction &, const MCInstrDesc &TID, DebugLoc DL,
bool NoImp = false);
// MachineInstrs are pool-allocated and owned by MachineFunction.
friend class MachineFunction;
void
dumprImpl(const MachineRegisterInfo &MRI, unsigned Depth, unsigned MaxDepth,
SmallPtrSetImpl<const MachineInstr *> &AlreadySeenInstrs) const;
public:
MachineInstr(const MachineInstr &) = delete;
MachineInstr &operator=(const MachineInstr &) = delete;
// Use MachineFunction::DeleteMachineInstr() instead.
~MachineInstr() = delete;
const MachineBasicBlock* getParent() const { return Parent; }
MachineBasicBlock* getParent() { return Parent; }
/// Move the instruction before \p MovePos.
void moveBefore(MachineInstr *MovePos);
/// Return the function that contains the basic block that this instruction
/// belongs to.
///
/// Note: this is undefined behaviour if the instruction does not have a
/// parent.
const MachineFunction *getMF() const;
MachineFunction *getMF() {
return const_cast<MachineFunction *>(
static_cast<const MachineInstr *>(this)->getMF());
}
/// Return the asm printer flags bitvector.
uint8_t getAsmPrinterFlags() const { return AsmPrinterFlags; }
/// Clear the AsmPrinter bitvector.
void clearAsmPrinterFlags() { AsmPrinterFlags = 0; }
/// Return whether an AsmPrinter flag is set.
bool getAsmPrinterFlag(CommentFlag Flag) const {
return AsmPrinterFlags & Flag;
}
/// Set a flag for the AsmPrinter.
void setAsmPrinterFlag(uint8_t Flag) {
AsmPrinterFlags |= Flag;
}
/// Clear specific AsmPrinter flags.
void clearAsmPrinterFlag(CommentFlag Flag) {
AsmPrinterFlags &= ~Flag;
}
/// Return the MI flags bitvector.
uint16_t getFlags() const {
return Flags;
}
/// Return whether an MI flag is set.
bool getFlag(MIFlag Flag) const {
return Flags & Flag;
}
/// Set a MI flag.
void setFlag(MIFlag Flag) {
Flags |= (uint16_t)Flag;
}
void setFlags(unsigned flags) {
// Filter out the automatically maintained flags.
unsigned Mask = BundledPred | BundledSucc;
Flags = (Flags & Mask) | (flags & ~Mask);
}
/// clearFlag - Clear a MI flag.
void clearFlag(MIFlag Flag) {
Flags &= ~((uint16_t)Flag);
}
/// Return true if MI is in a bundle (but not the first MI in a bundle).
///
/// A bundle looks like this before it's finalized:
/// ----------------
/// | MI |
/// ----------------
/// |
/// ----------------
/// | MI * |
/// ----------------
/// |
/// ----------------
/// | MI * |
/// ----------------
/// In this case, the first MI starts a bundle but is not inside a bundle, the
/// next 2 MIs are considered "inside" the bundle.
///
/// After a bundle is finalized, it looks like this:
/// ----------------
/// | Bundle |
/// ----------------
/// |
/// ----------------
/// | MI * |
/// ----------------
/// |
/// ----------------
/// | MI * |
/// ----------------
/// |
/// ----------------
/// | MI * |
/// ----------------
/// The first instruction has the special opcode "BUNDLE". It's not "inside"
/// a bundle, but the next three MIs are.
bool isInsideBundle() const {
return getFlag(BundledPred);
}
/// Return true if this instruction part of a bundle. This is true
/// if either itself or its following instruction is marked "InsideBundle".
bool isBundled() const {
return isBundledWithPred() || isBundledWithSucc();
}
/// Return true if this instruction is part of a bundle, and it is not the
/// first instruction in the bundle.
bool isBundledWithPred() const { return getFlag(BundledPred); }
/// Return true if this instruction is part of a bundle, and it is not the
/// last instruction in the bundle.
bool isBundledWithSucc() const { return getFlag(BundledSucc); }
/// Bundle this instruction with its predecessor. This can be an unbundled
/// instruction, or it can be the first instruction in a bundle.
void bundleWithPred();
/// Bundle this instruction with its successor. This can be an unbundled
/// instruction, or it can be the last instruction in a bundle.
void bundleWithSucc();
/// Break bundle above this instruction.
void unbundleFromPred();
/// Break bundle below this instruction.
void unbundleFromSucc();
/// Returns the debug location id of this MachineInstr.
const DebugLoc &getDebugLoc() const { return DbgLoc; }
/// Return the operand containing the offset to be used if this DBG_VALUE
/// instruction is indirect; will be an invalid register if this value is
/// not indirect, and an immediate with value 0 otherwise.
const MachineOperand &getDebugOffset() const {
assert(isNonListDebugValue() && "not a DBG_VALUE");
return getOperand(1);
}
MachineOperand &getDebugOffset() {
assert(isNonListDebugValue() && "not a DBG_VALUE");
return getOperand(1);
}
/// Return the operand for the debug variable referenced by
/// this DBG_VALUE instruction.
const MachineOperand &getDebugVariableOp() const;
MachineOperand &getDebugVariableOp();
/// Return the debug variable referenced by
/// this DBG_VALUE instruction.
const DILocalVariable *getDebugVariable() const;
/// Return the operand for the complex address expression referenced by
/// this DBG_VALUE instruction.
const MachineOperand &getDebugExpressionOp() const;
MachineOperand &getDebugExpressionOp();
/// Return the complex address expression referenced by
/// this DBG_VALUE instruction.
const DIExpression *getDebugExpression() const;
/// Return the debug label referenced by
/// this DBG_LABEL instruction.
const DILabel *getDebugLabel() const;
/// Fetch the instruction number of this MachineInstr. If it does not have
/// one already, a new and unique number will be assigned.
unsigned getDebugInstrNum();
/// Fetch instruction number of this MachineInstr -- but before it's inserted
/// into \p MF. Needed for transformations that create an instruction but
/// don't immediately insert them.
unsigned getDebugInstrNum(MachineFunction &MF);
/// Examine the instruction number of this MachineInstr. May be zero if
/// it hasn't been assigned a number yet.
unsigned peekDebugInstrNum() const { return DebugInstrNum; }
/// Set instruction number of this MachineInstr. Avoid using unless you're
/// deserializing this information.
void setDebugInstrNum(unsigned Num) { DebugInstrNum = Num; }
/// Drop any variable location debugging information associated with this
/// instruction. Use when an instruction is modified in such a way that it no
/// longer defines the value it used to. Variable locations using that value
/// will be dropped.
void dropDebugNumber() { DebugInstrNum = 0; }
/// Emit an error referring to the source location of this instruction.
/// This should only be used for inline assembly that is somehow
/// impossible to compile. Other errors should have been handled much
/// earlier.
///
/// If this method returns, the caller should try to recover from the error.
void emitError(StringRef Msg) const;
/// Returns the target instruction descriptor of this MachineInstr.
const MCInstrDesc &getDesc() const { return *MCID; }
/// Returns the opcode of this MachineInstr.
unsigned getOpcode() const { return MCID->Opcode; }
/// Retuns the total number of operands.
unsigned getNumOperands() const { return NumOperands; }
/// Returns the total number of operands which are debug locations.
unsigned getNumDebugOperands() const {
return std::distance(debug_operands().begin(), debug_operands().end());
}
const MachineOperand& getOperand(unsigned i) const {
assert(i < getNumOperands() && "getOperand() out of range!");
return Operands[i];
}
MachineOperand& getOperand(unsigned i) {
assert(i < getNumOperands() && "getOperand() out of range!");
return Operands[i];
}
MachineOperand &getDebugOperand(unsigned Index) {
assert(Index < getNumDebugOperands() && "getDebugOperand() out of range!");
return *(debug_operands().begin() + Index);
}
const MachineOperand &getDebugOperand(unsigned Index) const {
assert(Index < getNumDebugOperands() && "getDebugOperand() out of range!");
return *(debug_operands().begin() + Index);
}
SmallSet<Register, 4> getUsedDebugRegs() const {
assert(isDebugValue() && "not a DBG_VALUE*");
SmallSet<Register, 4> UsedRegs;
for (const auto &MO : debug_operands())
if (MO.isReg() && MO.getReg())
UsedRegs.insert(MO.getReg());
return UsedRegs;
}
/// Returns whether this debug value has at least one debug operand with the
/// register \p Reg.
bool hasDebugOperandForReg(Register Reg) const {
return any_of(debug_operands(), [Reg](const MachineOperand &Op) {
return Op.isReg() && Op.getReg() == Reg;
});
}
/// Returns a range of all of the operands that correspond to a debug use of
/// \p Reg.
template <typename Operand, typename Instruction>
static iterator_range<
filter_iterator<Operand *, std::function<bool(Operand &Op)>>>
getDebugOperandsForReg(Instruction *MI, Register Reg) {
std::function<bool(Operand & Op)> OpUsesReg(
[Reg](Operand &Op) { return Op.isReg() && Op.getReg() == Reg; });
return make_filter_range(MI->debug_operands(), OpUsesReg);
}
iterator_range<filter_iterator<const MachineOperand *,
std::function<bool(const MachineOperand &Op)>>>
getDebugOperandsForReg(Register Reg) const {
return MachineInstr::getDebugOperandsForReg<const MachineOperand,
const MachineInstr>(this, Reg);
}
iterator_range<filter_iterator<MachineOperand *,
std::function<bool(MachineOperand &Op)>>>
getDebugOperandsForReg(Register Reg) {
return MachineInstr::getDebugOperandsForReg<MachineOperand, MachineInstr>(
this, Reg);
}
bool isDebugOperand(const MachineOperand *Op) const {
return Op >= adl_begin(debug_operands()) && Op <= adl_end(debug_operands());
}
unsigned getDebugOperandIndex(const MachineOperand *Op) const {
assert(isDebugOperand(Op) && "Expected a debug operand.");
return std::distance(adl_begin(debug_operands()), Op);
}
/// Returns the total number of definitions.
unsigned getNumDefs() const {
return getNumExplicitDefs() + MCID->implicit_defs().size();
}
/// Returns true if the instruction has implicit definition.
bool hasImplicitDef() const {
for (const MachineOperand &MO : implicit_operands())
if (MO.isDef() && MO.isImplicit())
return true;
return false;
}
/// Returns the implicit operands number.
unsigned getNumImplicitOperands() const {
return getNumOperands() - getNumExplicitOperands();
}
/// Return true if operand \p OpIdx is a subregister index.
bool isOperandSubregIdx(unsigned OpIdx) const {
assert(getOperand(OpIdx).isImm() && "Expected MO_Immediate operand type.");
if (isExtractSubreg() && OpIdx == 2)
return true;
if (isInsertSubreg() && OpIdx == 3)
return true;
if (isRegSequence() && OpIdx > 1 && (OpIdx % 2) == 0)
return true;
if (isSubregToReg() && OpIdx == 3)
return true;
return false;
}
/// Returns the number of non-implicit operands.
unsigned getNumExplicitOperands() const;
/// Returns the number of non-implicit definitions.
unsigned getNumExplicitDefs() const;
/// iterator/begin/end - Iterate over all operands of a machine instruction.
using mop_iterator = MachineOperand *;
using const_mop_iterator = const MachineOperand *;
mop_iterator operands_begin() { return Operands; }
mop_iterator operands_end() { return Operands + NumOperands; }
const_mop_iterator operands_begin() const { return Operands; }
const_mop_iterator operands_end() const { return Operands + NumOperands; }
iterator_range<mop_iterator> operands() {
return make_range(operands_begin(), operands_end());
}
iterator_range<const_mop_iterator> operands() const {
return make_range(operands_begin(), operands_end());
}
iterator_range<mop_iterator> explicit_operands() {
return make_range(operands_begin(),
operands_begin() + getNumExplicitOperands());
}
iterator_range<const_mop_iterator> explicit_operands() const {
return make_range(operands_begin(),
operands_begin() + getNumExplicitOperands());
}
iterator_range<mop_iterator> implicit_operands() {
return make_range(explicit_operands().end(), operands_end());
}
iterator_range<const_mop_iterator> implicit_operands() const {
return make_range(explicit_operands().end(), operands_end());
}
/// Returns a range over all operands that are used to determine the variable
/// location for this DBG_VALUE instruction.
iterator_range<mop_iterator> debug_operands() {
assert((isDebugValueLike()) && "Must be a debug value instruction.");
return isNonListDebugValue()
? make_range(operands_begin(), operands_begin() + 1)
: make_range(operands_begin() + 2, operands_end());
}
/// \copydoc debug_operands()
iterator_range<const_mop_iterator> debug_operands() const {
assert((isDebugValueLike()) && "Must be a debug value instruction.");
return isNonListDebugValue()
? make_range(operands_begin(), operands_begin() + 1)
: make_range(operands_begin() + 2, operands_end());
}
/// Returns a range over all explicit operands that are register definitions.
/// Implicit definition are not included!
iterator_range<mop_iterator> defs() {
return make_range(operands_begin(),
operands_begin() + getNumExplicitDefs());
}
/// \copydoc defs()
iterator_range<const_mop_iterator> defs() const {
return make_range(operands_begin(),
operands_begin() + getNumExplicitDefs());
}
/// Returns a range that includes all operands that are register uses.
/// This may include unrelated operands which are not register uses.
iterator_range<mop_iterator> uses() {
return make_range(operands_begin() + getNumExplicitDefs(), operands_end());
}
/// \copydoc uses()
iterator_range<const_mop_iterator> uses() const {
return make_range(operands_begin() + getNumExplicitDefs(), operands_end());
}
iterator_range<mop_iterator> explicit_uses() {
return make_range(operands_begin() + getNumExplicitDefs(),
operands_begin() + getNumExplicitOperands());
}
iterator_range<const_mop_iterator> explicit_uses() const {
return make_range(operands_begin() + getNumExplicitDefs(),
operands_begin() + getNumExplicitOperands());
}
/// Returns the number of the operand iterator \p I points to.
unsigned getOperandNo(const_mop_iterator I) const {
return I - operands_begin();
}
/// Access to memory operands of the instruction. If there are none, that does
/// not imply anything about whether the function accesses memory. Instead,
/// the caller must behave conservatively.
ArrayRef<MachineMemOperand *> memoperands() const {
if (!Info)
return {};
if (Info.is<EIIK_MMO>())
return ArrayRef(Info.getAddrOfZeroTagPointer(), 1);
if (ExtraInfo *EI = Info.get<EIIK_OutOfLine>())
return EI->getMMOs();
return {};
}
/// Access to memory operands of the instruction.
///
/// If `memoperands_begin() == memoperands_end()`, that does not imply
/// anything about whether the function accesses memory. Instead, the caller
/// must behave conservatively.
mmo_iterator memoperands_begin() const { return memoperands().begin(); }
/// Access to memory operands of the instruction.
///
/// If `memoperands_begin() == memoperands_end()`, that does not imply
/// anything about whether the function accesses memory. Instead, the caller
/// must behave conservatively.
mmo_iterator memoperands_end() const { return memoperands().end(); }
/// Return true if we don't have any memory operands which described the
/// memory access done by this instruction. If this is true, calling code
/// must be conservative.
bool memoperands_empty() const { return memoperands().empty(); }
/// Return true if this instruction has exactly one MachineMemOperand.
bool hasOneMemOperand() const { return memoperands().size() == 1; }
/// Return the number of memory operands.
unsigned getNumMemOperands() const { return memoperands().size(); }
/// Helper to extract a pre-instruction symbol if one has been added.
MCSymbol *getPreInstrSymbol() const {
if (!Info)
return nullptr;
if (MCSymbol *S = Info.get<EIIK_PreInstrSymbol>())
return S;
if (ExtraInfo *EI = Info.get<EIIK_OutOfLine>())
return EI->getPreInstrSymbol();
return nullptr;
}
/// Helper to extract a post-instruction symbol if one has been added.
MCSymbol *getPostInstrSymbol() const {
if (!Info)
return nullptr;
if (MCSymbol *S = Info.get<EIIK_PostInstrSymbol>())
return S;
if (ExtraInfo *EI = Info.get<EIIK_OutOfLine>())
return EI->getPostInstrSymbol();
return nullptr;
}
/// Helper to extract a heap alloc marker if one has been added.
MDNode *getHeapAllocMarker() const {
if (!Info)
return nullptr;
if (ExtraInfo *EI = Info.get<EIIK_OutOfLine>())
return EI->getHeapAllocMarker();
return nullptr;
}
/// Helper to extract PCSections metadata target sections.
MDNode *getPCSections() const {
if (!Info)
return nullptr;
if (ExtraInfo *EI = Info.get<EIIK_OutOfLine>())
return EI->getPCSections();
return nullptr;
}
/// Helper to extract a CFI type hash if one has been added.
uint32_t getCFIType() const {
if (!Info)
return 0;
if (ExtraInfo *EI = Info.get<EIIK_OutOfLine>())
return EI->getCFIType();
return 0;
}
/// API for querying MachineInstr properties. They are the same as MCInstrDesc
/// queries but they are bundle aware.
enum QueryType {
IgnoreBundle, // Ignore bundles
AnyInBundle, // Return true if any instruction in bundle has property
AllInBundle // Return true if all instructions in bundle have property
};
/// Return true if the instruction (or in the case of a bundle,
/// the instructions inside the bundle) has the specified property.
/// The first argument is the property being queried.
/// The second argument indicates whether the query should look inside
/// instruction bundles.
bool hasProperty(unsigned MCFlag, QueryType Type = AnyInBundle) const {
assert(MCFlag < 64 &&
"MCFlag out of range for bit mask in getFlags/hasPropertyInBundle.");
// Inline the fast path for unbundled or bundle-internal instructions.
if (Type == IgnoreBundle || !isBundled() || isBundledWithPred())
return getDesc().getFlags() & (1ULL << MCFlag);
// If this is the first instruction in a bundle, take the slow path.
return hasPropertyInBundle(1ULL << MCFlag, Type);
}
/// Return true if this is an instruction that should go through the usual
/// legalization steps.
bool isPreISelOpcode(QueryType Type = IgnoreBundle) const {
return hasProperty(MCID::PreISelOpcode, Type);
}
/// Return true if this instruction can have a variable number of operands.
/// In this case, the variable operands will be after the normal
/// operands but before the implicit definitions and uses (if any are
/// present).
bool isVariadic(QueryType Type = IgnoreBundle) const {
return hasProperty(MCID::Variadic, Type);
}
/// Set if this instruction has an optional definition, e.g.
/// ARM instructions which can set condition code if 's' bit is set.
bool hasOptionalDef(QueryType Type = IgnoreBundle) const {
return hasProperty(MCID::HasOptionalDef, Type);
}
/// Return true if this is a pseudo instruction that doesn't
/// correspond to a real machine instruction.
bool isPseudo(QueryType Type = IgnoreBundle) const {
return hasProperty(MCID::Pseudo, Type);
}
/// Return true if this instruction doesn't produce any output in the form of
/// executable instructions.
bool isMetaInstruction(QueryType Type = IgnoreBundle) const {
return hasProperty(MCID::Meta, Type);
}
bool isReturn(QueryType Type = AnyInBundle) const {
return hasProperty(MCID::Return, Type);
}
/// Return true if this is an instruction that marks the end of an EH scope,
/// i.e., a catchpad or a cleanuppad instruction.
bool isEHScopeReturn(QueryType Type = AnyInBundle) const {
return hasProperty(MCID::EHScopeReturn, Type);
}
bool isCall(QueryType Type = AnyInBundle) const {
return hasProperty(MCID::Call, Type);
}
/// Return true if this is a call instruction that may have an associated
/// call site entry in the debug info.
bool isCandidateForCallSiteEntry(QueryType Type = IgnoreBundle) const;
/// Return true if copying, moving, or erasing this instruction requires
/// updating Call Site Info (see \ref copyCallSiteInfo, \ref moveCallSiteInfo,
/// \ref eraseCallSiteInfo).
bool shouldUpdateCallSiteInfo() const;
/// Returns true if the specified instruction stops control flow
/// from executing the instruction immediately following it. Examples include
/// unconditional branches and return instructions.
bool isBarrier(QueryType Type = AnyInBundle) const {
return hasProperty(MCID::Barrier, Type);
}
/// Returns true if this instruction part of the terminator for a basic block.
/// Typically this is things like return and branch instructions.
///
/// Various passes use this to insert code into the bottom of a basic block,
/// but before control flow occurs.
bool isTerminator(QueryType Type = AnyInBundle) const {
return hasProperty(MCID::Terminator, Type);
}
/// Returns true if this is a conditional, unconditional, or indirect branch.
/// Predicates below can be used to discriminate between
/// these cases, and the TargetInstrInfo::analyzeBranch method can be used to
/// get more information.
bool isBranch(QueryType Type = AnyInBundle) const {
return hasProperty(MCID::Branch, Type);
}
/// Return true if this is an indirect branch, such as a
/// branch through a register.
bool isIndirectBranch(QueryType Type = AnyInBundle) const {
return hasProperty(MCID::IndirectBranch, Type);
}
/// Return true if this is a branch which may fall
/// through to the next instruction or may transfer control flow to some other
/// block. The TargetInstrInfo::analyzeBranch method can be used to get more
/// information about this branch.
bool isConditionalBranch(QueryType Type = AnyInBundle) const {
return isBranch(Type) && !isBarrier(Type) && !isIndirectBranch(Type);
}
/// Return true if this is a branch which always
/// transfers control flow to some other block. The
/// TargetInstrInfo::analyzeBranch method can be used to get more information
/// about this branch.
bool isUnconditionalBranch(QueryType Type = AnyInBundle) const {
return isBranch(Type) && isBarrier(Type) && !isIndirectBranch(Type);
}
/// Return true if this instruction has a predicate operand that
/// controls execution. It may be set to 'always', or may be set to other
/// values. There are various methods in TargetInstrInfo that can be used to
/// control and modify the predicate in this instruction.
bool isPredicable(QueryType Type = AllInBundle) const {
// If it's a bundle than all bundled instructions must be predicable for this
// to return true.
return hasProperty(MCID::Predicable, Type);
}
/// Return true if this instruction is a comparison.
bool isCompare(QueryType Type = IgnoreBundle) const {
return hasProperty(MCID::Compare, Type);
}
/// Return true if this instruction is a move immediate
/// (including conditional moves) instruction.
bool isMoveImmediate(QueryType Type = IgnoreBundle) const {
return hasProperty(MCID::MoveImm, Type);
}
/// Return true if this instruction is a register move.
/// (including moving values from subreg to reg)
bool isMoveReg(QueryType Type = IgnoreBundle) const {
return hasProperty(MCID::MoveReg, Type);
}
/// Return true if this instruction is a bitcast instruction.
bool isBitcast(QueryType Type = IgnoreBundle) const {
return hasProperty(MCID::Bitcast, Type);
}
/// Return true if this instruction is a select instruction.
bool isSelect(QueryType Type = IgnoreBundle) const {
return hasProperty(MCID::Select, Type);
}
/// Return true if this instruction cannot be safely duplicated.
/// For example, if the instruction has a unique labels attached
/// to it, duplicating it would cause multiple definition errors.
bool isNotDuplicable(QueryType Type = AnyInBundle) const {
if (getPreInstrSymbol() || getPostInstrSymbol())
return true;
return hasProperty(MCID::NotDuplicable, Type);
}
/// Return true if this instruction is convergent.
/// Convergent instructions can not be made control-dependent on any
/// additional values.
bool isConvergent(QueryType Type = AnyInBundle) const {
if (isInlineAsm()) {
unsigned ExtraInfo = getOperand(InlineAsm::MIOp_ExtraInfo).getImm();
if (ExtraInfo & InlineAsm::Extra_IsConvergent)
return true;
}
return hasProperty(MCID::Convergent, Type);
}
/// Returns true if the specified instruction has a delay slot
/// which must be filled by the code generator.
bool hasDelaySlot(QueryType Type = AnyInBundle) const {
return hasProperty(MCID::DelaySlot, Type);
}
/// Return true for instructions that can be folded as
/// memory operands in other instructions. The most common use for this
/// is instructions that are simple loads from memory that don't modify
/// the loaded value in any way, but it can also be used for instructions
/// that can be expressed as constant-pool loads, such as V_SETALLONES
/// on x86, to allow them to be folded when it is beneficial.
/// This should only be set on instructions that return a value in their
/// only virtual register definition.
bool canFoldAsLoad(QueryType Type = IgnoreBundle) const {
return hasProperty(MCID::FoldableAsLoad, Type);
}
/// Return true if this instruction behaves
/// the same way as the generic REG_SEQUENCE instructions.
/// E.g., on ARM,
/// dX VMOVDRR rY, rZ
/// is equivalent to
/// dX = REG_SEQUENCE rY, ssub_0, rZ, ssub_1.
///
/// Note that for the optimizers to be able to take advantage of
/// this property, TargetInstrInfo::getRegSequenceLikeInputs has to be
/// override accordingly.
bool isRegSequenceLike(QueryType Type = IgnoreBundle) const {
return hasProperty(MCID::RegSequence, Type);
}
/// Return true if this instruction behaves
/// the same way as the generic EXTRACT_SUBREG instructions.
/// E.g., on ARM,
/// rX, rY VMOVRRD dZ
/// is equivalent to two EXTRACT_SUBREG:
/// rX = EXTRACT_SUBREG dZ, ssub_0
/// rY = EXTRACT_SUBREG dZ, ssub_1
///
/// Note that for the optimizers to be able to take advantage of
/// this property, TargetInstrInfo::getExtractSubregLikeInputs has to be
/// override accordingly.
bool isExtractSubregLike(QueryType Type = IgnoreBundle) const {
return hasProperty(MCID::ExtractSubreg, Type);
}
/// Return true if this instruction behaves
/// the same way as the generic INSERT_SUBREG instructions.
/// E.g., on ARM,
/// dX = VSETLNi32 dY, rZ, Imm
/// is equivalent to a INSERT_SUBREG:
/// dX = INSERT_SUBREG dY, rZ, translateImmToSubIdx(Imm)
///
/// Note that for the optimizers to be able to take advantage of
/// this property, TargetInstrInfo::getInsertSubregLikeInputs has to be
/// override accordingly.
bool isInsertSubregLike(QueryType Type = IgnoreBundle) const {
return hasProperty(MCID::InsertSubreg, Type);
}
//===--------------------------------------------------------------------===//
// Side Effect Analysis
//===--------------------------------------------------------------------===//
/// Return true if this instruction could possibly read memory.
/// Instructions with this flag set are not necessarily simple load
/// instructions, they may load a value and modify it, for example.
bool mayLoad(QueryType Type = AnyInBundle) const {
if (isInlineAsm()) {
unsigned ExtraInfo = getOperand(InlineAsm::MIOp_ExtraInfo).getImm();
if (ExtraInfo & InlineAsm::Extra_MayLoad)
return true;
}
return hasProperty(MCID::MayLoad, Type);
}
/// Return true if this instruction could possibly modify memory.
/// Instructions with this flag set are not necessarily simple store
/// instructions, they may store a modified value based on their operands, or
/// may not actually modify anything, for example.
bool mayStore(QueryType Type = AnyInBundle) const {
if (isInlineAsm()) {
unsigned ExtraInfo = getOperand(InlineAsm::MIOp_ExtraInfo).getImm();
if (ExtraInfo & InlineAsm::Extra_MayStore)
return true;
}
return hasProperty(MCID::MayStore, Type);
}
/// Return true if this instruction could possibly read or modify memory.
bool mayLoadOrStore(QueryType Type = AnyInBundle) const {
return mayLoad(Type) || mayStore(Type);
}
/// Return true if this instruction could possibly raise a floating-point
/// exception. This is the case if the instruction is a floating-point
/// instruction that can in principle raise an exception, as indicated
/// by the MCID::MayRaiseFPException property, *and* at the same time,
/// the instruction is used in a context where we expect floating-point
/// exceptions are not disabled, as indicated by the NoFPExcept MI flag.
bool mayRaiseFPException() const {
return hasProperty(MCID::MayRaiseFPException) &&
!getFlag(MachineInstr::MIFlag::NoFPExcept);
}
//===--------------------------------------------------------------------===//
// Flags that indicate whether an instruction can be modified by a method.
//===--------------------------------------------------------------------===//
/// Return true if this may be a 2- or 3-address
/// instruction (of the form "X = op Y, Z, ..."), which produces the same
/// result if Y and Z are exchanged. If this flag is set, then the
/// TargetInstrInfo::commuteInstruction method may be used to hack on the
/// instruction.
///
/// Note that this flag may be set on instructions that are only commutable
/// sometimes. In these cases, the call to commuteInstruction will fail.
/// Also note that some instructions require non-trivial modification to
/// commute them.
bool isCommutable(QueryType Type = IgnoreBundle) const {
return hasProperty(MCID::Commutable, Type);
}
/// Return true if this is a 2-address instruction
/// which can be changed into a 3-address instruction if needed. Doing this
/// transformation can be profitable in the register allocator, because it
/// means that the instruction can use a 2-address form if possible, but
/// degrade into a less efficient form if the source and dest register cannot
/// be assigned to the same register. For example, this allows the x86
/// backend to turn a "shl reg, 3" instruction into an LEA instruction, which
/// is the same speed as the shift but has bigger code size.
///
/// If this returns true, then the target must implement the
/// TargetInstrInfo::convertToThreeAddress method for this instruction, which
/// is allowed to fail if the transformation isn't valid for this specific
/// instruction (e.g. shl reg, 4 on x86).
///
bool isConvertibleTo3Addr(QueryType Type = IgnoreBundle) const {
return hasProperty(MCID::ConvertibleTo3Addr, Type);
}
/// Return true if this instruction requires
/// custom insertion support when the DAG scheduler is inserting it into a
/// machine basic block. If this is true for the instruction, it basically
/// means that it is a pseudo instruction used at SelectionDAG time that is
/// expanded out into magic code by the target when MachineInstrs are formed.
///
/// If this is true, the TargetLoweringInfo::InsertAtEndOfBasicBlock method
/// is used to insert this into the MachineBasicBlock.
bool usesCustomInsertionHook(QueryType Type = IgnoreBundle) const {
return hasProperty(MCID::UsesCustomInserter, Type);
}
/// Return true if this instruction requires *adjustment*
/// after instruction selection by calling a target hook. For example, this
/// can be used to fill in ARM 's' optional operand depending on whether
/// the conditional flag register is used.
bool hasPostISelHook(QueryType Type = IgnoreBundle) const {
return hasProperty(MCID::HasPostISelHook, Type);
}
/// Returns true if this instruction is a candidate for remat.
/// This flag is deprecated, please don't use it anymore. If this
/// flag is set, the isReallyTriviallyReMaterializable() method is called to
/// verify the instruction is really rematable.
bool isRematerializable(QueryType Type = AllInBundle) const {
// It's only possible to re-mat a bundle if all bundled instructions are
// re-materializable.
return hasProperty(MCID::Rematerializable, Type);
}
/// Returns true if this instruction has the same cost (or less) than a move
/// instruction. This is useful during certain types of optimizations
/// (e.g., remat during two-address conversion or machine licm)
/// where we would like to remat or hoist the instruction, but not if it costs
/// more than moving the instruction into the appropriate register. Note, we
/// are not marking copies from and to the same register class with this flag.
bool isAsCheapAsAMove(QueryType Type = AllInBundle) const {
// Only returns true for a bundle if all bundled instructions are cheap.
return hasProperty(MCID::CheapAsAMove, Type);
}
/// Returns true if this instruction source operands
/// have special register allocation requirements that are not captured by the
/// operand register classes. e.g. ARM::STRD's two source registers must be an
/// even / odd pair, ARM::STM registers have to be in ascending order.
/// Post-register allocation passes should not attempt to change allocations
/// for sources of instructions with this flag.
bool hasExtraSrcRegAllocReq(QueryType Type = AnyInBundle) const {
return hasProperty(MCID::ExtraSrcRegAllocReq, Type);
}
/// Returns true if this instruction def operands
/// have special register allocation requirements that are not captured by the
/// operand register classes. e.g. ARM::LDRD's two def registers must be an
/// even / odd pair, ARM::LDM registers have to be in ascending order.
/// Post-register allocation passes should not attempt to change allocations
/// for definitions of instructions with this flag.
bool hasExtraDefRegAllocReq(QueryType Type = AnyInBundle) const {
return hasProperty(MCID::ExtraDefRegAllocReq, Type);
}
enum MICheckType {
CheckDefs, // Check all operands for equality
CheckKillDead, // Check all operands including kill / dead markers
IgnoreDefs, // Ignore all definitions
IgnoreVRegDefs // Ignore virtual register definitions
};
/// Return true if this instruction is identical to \p Other.
/// Two instructions are identical if they have the same opcode and all their
/// operands are identical (with respect to MachineOperand::isIdenticalTo()).
/// Note that this means liveness related flags (dead, undef, kill) do not
/// affect the notion of identical.
bool isIdenticalTo(const MachineInstr &Other,
MICheckType Check = CheckDefs) const;
/// Returns true if this instruction is a debug instruction that represents an
/// identical debug value to \p Other.
/// This function considers these debug instructions equivalent if they have
/// identical variables, debug locations, and debug operands, and if the
/// DIExpressions combined with the directness flags are equivalent.
bool isEquivalentDbgInstr(const MachineInstr &Other) const;
/// Unlink 'this' from the containing basic block, and return it without
/// deleting it.
///
/// This function can not be used on bundled instructions, use
/// removeFromBundle() to remove individual instructions from a bundle.
MachineInstr *removeFromParent();
/// Unlink this instruction from its basic block and return it without
/// deleting it.
///
/// If the instruction is part of a bundle, the other instructions in the
/// bundle remain bundled.
MachineInstr *removeFromBundle();
/// Unlink 'this' from the containing basic block and delete it.
///
/// If this instruction is the header of a bundle, the whole bundle is erased.
/// This function can not be used for instructions inside a bundle, use
/// eraseFromBundle() to erase individual bundled instructions.
void eraseFromParent();
/// Unlink 'this' form its basic block and delete it.
///
/// If the instruction is part of a bundle, the other instructions in the
/// bundle remain bundled.
void eraseFromBundle();
bool isEHLabel() const { return getOpcode() == TargetOpcode::EH_LABEL; }
bool isGCLabel() const { return getOpcode() == TargetOpcode::GC_LABEL; }
bool isAnnotationLabel() const {
return getOpcode() == TargetOpcode::ANNOTATION_LABEL;
}
/// Returns true if the MachineInstr represents a label.
bool isLabel() const {
return isEHLabel() || isGCLabel() || isAnnotationLabel();
}
bool isCFIInstruction() const {
return getOpcode() == TargetOpcode::CFI_INSTRUCTION;
}
bool isPseudoProbe() const {
return getOpcode() == TargetOpcode::PSEUDO_PROBE;
}
// True if the instruction represents a position in the function.
bool isPosition() const { return isLabel() || isCFIInstruction(); }
bool isNonListDebugValue() const {
return getOpcode() == TargetOpcode::DBG_VALUE;
}
bool isDebugValueList() const {
return getOpcode() == TargetOpcode::DBG_VALUE_LIST;
}
bool isDebugValue() const {
return isNonListDebugValue() || isDebugValueList();
}
bool isDebugLabel() const { return getOpcode() == TargetOpcode::DBG_LABEL; }
bool isDebugRef() const { return getOpcode() == TargetOpcode::DBG_INSTR_REF; }
bool isDebugValueLike() const { return isDebugValue() || isDebugRef(); }
bool isDebugPHI() const { return getOpcode() == TargetOpcode::DBG_PHI; }
bool isDebugInstr() const {
return isDebugValue() || isDebugLabel() || isDebugRef() || isDebugPHI();
}
bool isDebugOrPseudoInstr() const {
return isDebugInstr() || isPseudoProbe();
}
bool isDebugOffsetImm() const {
return isNonListDebugValue() && getDebugOffset().isImm();
}
/// A DBG_VALUE is indirect iff the location operand is a register and
/// the offset operand is an immediate.
bool isIndirectDebugValue() const {
return isDebugOffsetImm() && getDebugOperand(0).isReg();
}
/// A DBG_VALUE is an entry value iff its debug expression contains the
/// DW_OP_LLVM_entry_value operation.
bool isDebugEntryValue() const;
/// Return true if the instruction is a debug value which describes a part of
/// a variable as unavailable.
bool isUndefDebugValue() const {
if (!isDebugValue())
return false;
// If any $noreg locations are given, this DV is undef.
for (const MachineOperand &Op : debug_operands())
if (Op.isReg() && !Op.getReg().isValid())
return true;
return false;
}
bool isPHI() const {
return getOpcode() == TargetOpcode::PHI ||
getOpcode() == TargetOpcode::G_PHI;
}
bool isKill() const { return getOpcode() == TargetOpcode::KILL; }
bool isImplicitDef() const { return getOpcode()==TargetOpcode::IMPLICIT_DEF; }
bool isInlineAsm() const {
return getOpcode() == TargetOpcode::INLINEASM ||
getOpcode() == TargetOpcode::INLINEASM_BR;
}
/// FIXME: Seems like a layering violation that the AsmDialect, which is X86
/// specific, be attached to a generic MachineInstr.
bool isMSInlineAsm() const {
return isInlineAsm() && getInlineAsmDialect() == InlineAsm::AD_Intel;
}
bool isStackAligningInlineAsm() const;
InlineAsm::AsmDialect getInlineAsmDialect() const;
bool isInsertSubreg() const {
return getOpcode() == TargetOpcode::INSERT_SUBREG;
}
bool isSubregToReg() const {
return getOpcode() == TargetOpcode::SUBREG_TO_REG;
}
bool isRegSequence() const {
return getOpcode() == TargetOpcode::REG_SEQUENCE;
}
bool isBundle() const {
return getOpcode() == TargetOpcode::BUNDLE;
}
bool isCopy() const {
return getOpcode() == TargetOpcode::COPY;
}
bool isFullCopy() const {
return isCopy() && !getOperand(0).getSubReg() && !getOperand(1).getSubReg();
}
bool isExtractSubreg() const {
return getOpcode() == TargetOpcode::EXTRACT_SUBREG;
}
/// Return true if the instruction behaves like a copy.
/// This does not include native copy instructions.
bool isCopyLike() const {
return isCopy() || isSubregToReg();
}
/// Return true is the instruction is an identity copy.
bool isIdentityCopy() const {
return isCopy() && getOperand(0).getReg() == getOperand(1).getReg() &&
getOperand(0).getSubReg() == getOperand(1).getSubReg();
}
/// Return true if this is a transient instruction that is either very likely
/// to be eliminated during register allocation (such as copy-like
/// instructions), or if this instruction doesn't have an execution-time cost.
bool isTransient() const {
switch (getOpcode()) {
default:
return isMetaInstruction();
// Copy-like instructions are usually eliminated during register allocation.
case TargetOpcode::PHI:
case TargetOpcode::G_PHI:
case TargetOpcode::COPY:
case TargetOpcode::INSERT_SUBREG:
case TargetOpcode::SUBREG_TO_REG:
case TargetOpcode::REG_SEQUENCE:
return true;
}
}
/// Return the number of instructions inside the MI bundle, excluding the
/// bundle header.
///
/// This is the number of instructions that MachineBasicBlock::iterator
/// skips, 0 for unbundled instructions.
unsigned getBundleSize() const;
/// Return true if the MachineInstr reads the specified register.
/// If TargetRegisterInfo is passed, then it also checks if there
/// is a read of a super-register.
/// This does not count partial redefines of virtual registers as reads:
/// %reg1024:6 = OP.
bool readsRegister(Register Reg,
const TargetRegisterInfo *TRI = nullptr) const {
return findRegisterUseOperandIdx(Reg, false, TRI) != -1;
}
/// Return true if the MachineInstr reads the specified virtual register.
/// Take into account that a partial define is a
/// read-modify-write operation.
bool readsVirtualRegister(Register Reg) const {
return readsWritesVirtualRegister(Reg).first;
}
/// Return a pair of bools (reads, writes) indicating if this instruction
/// reads or writes Reg. This also considers partial defines.
/// If Ops is not null, all operand indices for Reg are added.
std::pair<bool,bool> readsWritesVirtualRegister(Register Reg,
SmallVectorImpl<unsigned> *Ops = nullptr) const;
/// Return true if the MachineInstr kills the specified register.
/// If TargetRegisterInfo is passed, then it also checks if there is
/// a kill of a super-register.
bool killsRegister(Register Reg,
const TargetRegisterInfo *TRI = nullptr) const {
return findRegisterUseOperandIdx(Reg, true, TRI) != -1;
}
/// Return true if the MachineInstr fully defines the specified register.
/// If TargetRegisterInfo is passed, then it also checks
/// if there is a def of a super-register.
/// NOTE: It's ignoring subreg indices on virtual registers.
bool definesRegister(Register Reg,
const TargetRegisterInfo *TRI = nullptr) const {
return findRegisterDefOperandIdx(Reg, false, false, TRI) != -1;
}
/// Return true if the MachineInstr modifies (fully define or partially
/// define) the specified register.
/// NOTE: It's ignoring subreg indices on virtual registers.
bool modifiesRegister(Register Reg,
const TargetRegisterInfo *TRI = nullptr) const {
return findRegisterDefOperandIdx(Reg, false, true, TRI) != -1;
}
/// Returns true if the register is dead in this machine instruction.
/// If TargetRegisterInfo is passed, then it also checks
/// if there is a dead def of a super-register.
bool registerDefIsDead(Register Reg,
const TargetRegisterInfo *TRI = nullptr) const {
return findRegisterDefOperandIdx(Reg, true, false, TRI) != -1;
}
/// Returns true if the MachineInstr has an implicit-use operand of exactly
/// the given register (not considering sub/super-registers).
bool hasRegisterImplicitUseOperand(Register Reg) const;
/// Returns the operand index that is a use of the specific register or -1
/// if it is not found. It further tightens the search criteria to a use
/// that kills the register if isKill is true.
int findRegisterUseOperandIdx(Register Reg, bool isKill = false,
const TargetRegisterInfo *TRI = nullptr) const;
/// Wrapper for findRegisterUseOperandIdx, it returns
/// a pointer to the MachineOperand rather than an index.
MachineOperand *findRegisterUseOperand(Register Reg, bool isKill = false,
const TargetRegisterInfo *TRI = nullptr) {
int Idx = findRegisterUseOperandIdx(Reg, isKill, TRI);
return (Idx == -1) ? nullptr : &getOperand(Idx);
}
const MachineOperand *findRegisterUseOperand(
Register Reg, bool isKill = false,
const TargetRegisterInfo *TRI = nullptr) const {
return const_cast<MachineInstr *>(this)->
findRegisterUseOperand(Reg, isKill, TRI);
}
/// Returns the operand index that is a def of the specified register or
/// -1 if it is not found. If isDead is true, defs that are not dead are
/// skipped. If Overlap is true, then it also looks for defs that merely
/// overlap the specified register. If TargetRegisterInfo is non-null,
/// then it also checks if there is a def of a super-register.
/// This may also return a register mask operand when Overlap is true.
int findRegisterDefOperandIdx(Register Reg,
bool isDead = false, bool Overlap = false,
const TargetRegisterInfo *TRI = nullptr) const;
/// Wrapper for findRegisterDefOperandIdx, it returns
/// a pointer to the MachineOperand rather than an index.
MachineOperand *
findRegisterDefOperand(Register Reg, bool isDead = false,
bool Overlap = false,
const TargetRegisterInfo *TRI = nullptr) {
int Idx = findRegisterDefOperandIdx(Reg, isDead, Overlap, TRI);
return (Idx == -1) ? nullptr : &getOperand(Idx);
}
const MachineOperand *
findRegisterDefOperand(Register Reg, bool isDead = false,
bool Overlap = false,
const TargetRegisterInfo *TRI = nullptr) const {
return const_cast<MachineInstr *>(this)->findRegisterDefOperand(
Reg, isDead, Overlap, TRI);
}
/// Find the index of the first operand in the
/// operand list that is used to represent the predicate. It returns -1 if
/// none is found.
int findFirstPredOperandIdx() const;
/// Find the index of the flag word operand that
/// corresponds to operand OpIdx on an inline asm instruction. Returns -1 if
/// getOperand(OpIdx) does not belong to an inline asm operand group.
///
/// If GroupNo is not NULL, it will receive the number of the operand group
/// containing OpIdx.
int findInlineAsmFlagIdx(unsigned OpIdx, unsigned *GroupNo = nullptr) const;
/// Compute the static register class constraint for operand OpIdx.
/// For normal instructions, this is derived from the MCInstrDesc.
/// For inline assembly it is derived from the flag words.
///
/// Returns NULL if the static register class constraint cannot be
/// determined.
const TargetRegisterClass*
getRegClassConstraint(unsigned OpIdx,
const TargetInstrInfo *TII,
const TargetRegisterInfo *TRI) const;
/// Applies the constraints (def/use) implied by this MI on \p Reg to
/// the given \p CurRC.
/// If \p ExploreBundle is set and MI is part of a bundle, all the
/// instructions inside the bundle will be taken into account. In other words,
/// this method accumulates all the constraints of the operand of this MI and
/// the related bundle if MI is a bundle or inside a bundle.
///
/// Returns the register class that satisfies both \p CurRC and the
/// constraints set by MI. Returns NULL if such a register class does not
/// exist.
///
/// \pre CurRC must not be NULL.
const TargetRegisterClass *getRegClassConstraintEffectForVReg(
Register Reg, const TargetRegisterClass *CurRC,
const TargetInstrInfo *TII, const TargetRegisterInfo *TRI,
bool ExploreBundle = false) const;
/// Applies the constraints (def/use) implied by the \p OpIdx operand
/// to the given \p CurRC.
///
/// Returns the register class that satisfies both \p CurRC and the
/// constraints set by \p OpIdx MI. Returns NULL if such a register class
/// does not exist.
///
/// \pre CurRC must not be NULL.
/// \pre The operand at \p OpIdx must be a register.
const TargetRegisterClass *
getRegClassConstraintEffect(unsigned OpIdx, const TargetRegisterClass *CurRC,
const TargetInstrInfo *TII,
const TargetRegisterInfo *TRI) const;
/// Add a tie between the register operands at DefIdx and UseIdx.
/// The tie will cause the register allocator to ensure that the two
/// operands are assigned the same physical register.
///
/// Tied operands are managed automatically for explicit operands in the
/// MCInstrDesc. This method is for exceptional cases like inline asm.
void tieOperands(unsigned DefIdx, unsigned UseIdx);
/// Given the index of a tied register operand, find the
/// operand it is tied to. Defs are tied to uses and vice versa. Returns the
/// index of the tied operand which must exist.
unsigned findTiedOperandIdx(unsigned OpIdx) const;
/// Given the index of a register def operand,
/// check if the register def is tied to a source operand, due to either
/// two-address elimination or inline assembly constraints. Returns the
/// first tied use operand index by reference if UseOpIdx is not null.
bool isRegTiedToUseOperand(unsigned DefOpIdx,
unsigned *UseOpIdx = nullptr) const {
const MachineOperand &MO = getOperand(DefOpIdx);
if (!MO.isReg() || !MO.isDef() || !MO.isTied())
return false;
if (UseOpIdx)
*UseOpIdx = findTiedOperandIdx(DefOpIdx);
return true;
}
/// Return true if the use operand of the specified index is tied to a def
/// operand. It also returns the def operand index by reference if DefOpIdx
/// is not null.
bool isRegTiedToDefOperand(unsigned UseOpIdx,
unsigned *DefOpIdx = nullptr) const {
const MachineOperand &MO = getOperand(UseOpIdx);
if (!MO.isReg() || !MO.isUse() || !MO.isTied())
return false;
if (DefOpIdx)
*DefOpIdx = findTiedOperandIdx(UseOpIdx);
return true;
}
/// Clears kill flags on all operands.
void clearKillInfo();
/// Replace all occurrences of FromReg with ToReg:SubIdx,
/// properly composing subreg indices where necessary.
void substituteRegister(Register FromReg, Register ToReg, unsigned SubIdx,
const TargetRegisterInfo &RegInfo);
/// We have determined MI kills a register. Look for the
/// operand that uses it and mark it as IsKill. If AddIfNotFound is true,
/// add a implicit operand if it's not found. Returns true if the operand
/// exists / is added.
bool addRegisterKilled(Register IncomingReg,
const TargetRegisterInfo *RegInfo,
bool AddIfNotFound = false);
/// Clear all kill flags affecting Reg. If RegInfo is provided, this includes
/// all aliasing registers.
void clearRegisterKills(Register Reg, const TargetRegisterInfo *RegInfo);
/// We have determined MI defined a register without a use.
/// Look for the operand that defines it and mark it as IsDead. If
/// AddIfNotFound is true, add a implicit operand if it's not found. Returns
/// true if the operand exists / is added.
bool addRegisterDead(Register Reg, const TargetRegisterInfo *RegInfo,
bool AddIfNotFound = false);
/// Clear all dead flags on operands defining register @p Reg.
void clearRegisterDeads(Register Reg);
/// Mark all subregister defs of register @p Reg with the undef flag.
/// This function is used when we determined to have a subregister def in an
/// otherwise undefined super register.
void setRegisterDefReadUndef(Register Reg, bool IsUndef = true);
/// We have determined MI defines a register. Make sure there is an operand
/// defining Reg.
void addRegisterDefined(Register Reg,
const TargetRegisterInfo *RegInfo = nullptr);
/// Mark every physreg used by this instruction as
/// dead except those in the UsedRegs list.
///
/// On instructions with register mask operands, also add implicit-def
/// operands for all registers in UsedRegs.
void setPhysRegsDeadExcept(ArrayRef<Register> UsedRegs,
const TargetRegisterInfo &TRI);
/// Return true if it is safe to move this instruction. If
/// SawStore is set to true, it means that there is a store (or call) between
/// the instruction's location and its intended destination.
bool isSafeToMove(AAResults *AA, bool &SawStore) const;
/// Returns true if this instruction's memory access aliases the memory
/// access of Other.
//
/// Assumes any physical registers used to compute addresses
/// have the same value for both instructions. Returns false if neither
/// instruction writes to memory.
///
/// @param AA Optional alias analysis, used to compare memory operands.
/// @param Other MachineInstr to check aliasing against.
/// @param UseTBAA Whether to pass TBAA information to alias analysis.
bool mayAlias(AAResults *AA, const MachineInstr &Other, bool UseTBAA) const;
/// Return true if this instruction may have an ordered
/// or volatile memory reference, or if the information describing the memory
/// reference is not available. Return false if it is known to have no
/// ordered or volatile memory references.
bool hasOrderedMemoryRef() const;
/// Return true if this load instruction never traps and points to a memory
/// location whose value doesn't change during the execution of this function.
///
/// Examples include loading a value from the constant pool or from the
/// argument area of a function (if it does not change). If the instruction
/// does multiple loads, this returns true only if all of the loads are
/// dereferenceable and invariant.
bool isDereferenceableInvariantLoad() const;
/// If the specified instruction is a PHI that always merges together the
/// same virtual register, return the register, otherwise return 0.
unsigned isConstantValuePHI() const;
/// Return true if this instruction has side effects that are not modeled
/// by mayLoad / mayStore, etc.
/// For all instructions, the property is encoded in MCInstrDesc::Flags
/// (see MCInstrDesc::hasUnmodeledSideEffects(). The only exception is
/// INLINEASM instruction, in which case the side effect property is encoded
/// in one of its operands (see InlineAsm::Extra_HasSideEffect).
///
bool hasUnmodeledSideEffects() const;
/// Returns true if it is illegal to fold a load across this instruction.
bool isLoadFoldBarrier() const;
/// Return true if all the defs of this instruction are dead.
bool allDefsAreDead() const;
/// Return a valid size if the instruction is a spill instruction.
std::optional<unsigned> getSpillSize(const TargetInstrInfo *TII) const;
/// Return a valid size if the instruction is a folded spill instruction.
std::optional<unsigned> getFoldedSpillSize(const TargetInstrInfo *TII) const;
/// Return a valid size if the instruction is a restore instruction.
std::optional<unsigned> getRestoreSize(const TargetInstrInfo *TII) const;
/// Return a valid size if the instruction is a folded restore instruction.
std::optional<unsigned>
getFoldedRestoreSize(const TargetInstrInfo *TII) const;
/// Copy implicit register operands from specified
/// instruction to this instruction.
void copyImplicitOps(MachineFunction &MF, const MachineInstr &MI);
/// Debugging support
/// @{
/// Determine the generic type to be printed (if needed) on uses and defs.
LLT getTypeToPrint(unsigned OpIdx, SmallBitVector &PrintedTypes,
const MachineRegisterInfo &MRI) const;
/// Return true when an instruction has tied register that can't be determined
/// by the instruction's descriptor. This is useful for MIR printing, to
/// determine whether we need to print the ties or not.
bool hasComplexRegisterTies() const;
/// Print this MI to \p OS.
/// Don't print information that can be inferred from other instructions if
/// \p IsStandalone is false. It is usually true when only a fragment of the
/// function is printed.
/// Only print the defs and the opcode if \p SkipOpers is true.
/// Otherwise, also print operands if \p SkipDebugLoc is true.
/// Otherwise, also print the debug loc, with a terminating newline.
/// \p TII is used to print the opcode name. If it's not present, but the
/// MI is in a function, the opcode will be printed using the function's TII.
void print(raw_ostream &OS, bool IsStandalone = true, bool SkipOpers = false,
bool SkipDebugLoc = false, bool AddNewLine = true,
const TargetInstrInfo *TII = nullptr) const;
void print(raw_ostream &OS, ModuleSlotTracker &MST, bool IsStandalone = true,
bool SkipOpers = false, bool SkipDebugLoc = false,
bool AddNewLine = true,
const TargetInstrInfo *TII = nullptr) const;
void dump() const;
/// Print on dbgs() the current instruction and the instructions defining its
/// operands and so on until we reach \p MaxDepth.
void dumpr(const MachineRegisterInfo &MRI,
unsigned MaxDepth = UINT_MAX) const;
/// @}
//===--------------------------------------------------------------------===//
// Accessors used to build up machine instructions.
/// Add the specified operand to the instruction. If it is an implicit
/// operand, it is added to the end of the operand list. If it is an
/// explicit operand it is added at the end of the explicit operand list
/// (before the first implicit operand).
///
/// MF must be the machine function that was used to allocate this
/// instruction.
///
/// MachineInstrBuilder provides a more convenient interface for creating
/// instructions and adding operands.
void addOperand(MachineFunction &MF, const MachineOperand &Op);
/// Add an operand without providing an MF reference. This only works for
/// instructions that are inserted in a basic block.
///
/// MachineInstrBuilder and the two-argument addOperand(MF, MO) should be
/// preferred.
void addOperand(const MachineOperand &Op);
/// Replace the instruction descriptor (thus opcode) of
/// the current instruction with a new one.
void setDesc(const MCInstrDesc &TID) { MCID = &TID; }
/// Replace current source information with new such.
/// Avoid using this, the constructor argument is preferable.
void setDebugLoc(DebugLoc DL) {
DbgLoc = std::move(DL);
assert(DbgLoc.hasTrivialDestructor() && "Expected trivial destructor");
}
/// Erase an operand from an instruction, leaving it with one
/// fewer operand than it started with.
void removeOperand(unsigned OpNo);
/// Clear this MachineInstr's memory reference descriptor list. This resets
/// the memrefs to their most conservative state. This should be used only
/// as a last resort since it greatly pessimizes our knowledge of the memory
/// access performed by the instruction.
void dropMemRefs(MachineFunction &MF);
/// Assign this MachineInstr's memory reference descriptor list.
///
/// Unlike other methods, this *will* allocate them into a new array
/// associated with the provided `MachineFunction`.
void setMemRefs(MachineFunction &MF, ArrayRef<MachineMemOperand *> MemRefs);
/// Add a MachineMemOperand to the machine instruction.
/// This function should be used only occasionally. The setMemRefs function
/// is the primary method for setting up a MachineInstr's MemRefs list.
void addMemOperand(MachineFunction &MF, MachineMemOperand *MO);
/// Clone another MachineInstr's memory reference descriptor list and replace
/// ours with it.
///
/// Note that `*this` may be the incoming MI!
///
/// Prefer this API whenever possible as it can avoid allocations in common
/// cases.
void cloneMemRefs(MachineFunction &MF, const MachineInstr &MI);
/// Clone the merge of multiple MachineInstrs' memory reference descriptors
/// list and replace ours with it.
///
/// Note that `*this` may be one of the incoming MIs!
///
/// Prefer this API whenever possible as it can avoid allocations in common
/// cases.
void cloneMergedMemRefs(MachineFunction &MF,
ArrayRef<const MachineInstr *> MIs);
/// Set a symbol that will be emitted just prior to the instruction itself.
///
/// Setting this to a null pointer will remove any such symbol.
///
/// FIXME: This is not fully implemented yet.
void setPreInstrSymbol(MachineFunction &MF, MCSymbol *Symbol);
/// Set a symbol that will be emitted just after the instruction itself.
///
/// Setting this to a null pointer will remove any such symbol.
///
/// FIXME: This is not fully implemented yet.
void setPostInstrSymbol(MachineFunction &MF, MCSymbol *Symbol);
/// Clone another MachineInstr's pre- and post- instruction symbols and
/// replace ours with it.
void cloneInstrSymbols(MachineFunction &MF, const MachineInstr &MI);
/// Set a marker on instructions that denotes where we should create and emit
/// heap alloc site labels. This waits until after instruction selection and
/// optimizations to create the label, so it should still work if the
/// instruction is removed or duplicated.
void setHeapAllocMarker(MachineFunction &MF, MDNode *MD);
// Set metadata on instructions that say which sections to emit instruction
// addresses into.
void setPCSections(MachineFunction &MF, MDNode *MD);
/// Set the CFI type for the instruction.
void setCFIType(MachineFunction &MF, uint32_t Type);
/// Return the MIFlags which represent both MachineInstrs. This
/// should be used when merging two MachineInstrs into one. This routine does
/// not modify the MIFlags of this MachineInstr.
uint16_t mergeFlagsWith(const MachineInstr& Other) const;
static uint16_t copyFlagsFromInstruction(const Instruction &I);
/// Copy all flags to MachineInst MIFlags
void copyIRFlags(const Instruction &I);
/// Break any tie involving OpIdx.
void untieRegOperand(unsigned OpIdx) {
MachineOperand &MO = getOperand(OpIdx);
if (MO.isReg() && MO.isTied()) {
getOperand(findTiedOperandIdx(OpIdx)).TiedTo = 0;
MO.TiedTo = 0;
}
}
/// Add all implicit def and use operands to this instruction.
void addImplicitDefUseOperands(MachineFunction &MF);
/// Scan instructions immediately following MI and collect any matching
/// DBG_VALUEs.
void collectDebugValues(SmallVectorImpl<MachineInstr *> &DbgValues);
/// Find all DBG_VALUEs that point to the register def in this instruction
/// and point them to \p Reg instead.
void changeDebugValuesDefReg(Register Reg);
/// Returns the Intrinsic::ID for this instruction.
/// \pre Must have an intrinsic ID operand.
unsigned getIntrinsicID() const {
return getOperand(getNumExplicitDefs()).getIntrinsicID();
}
/// Sets all register debug operands in this debug value instruction to be
/// undef.
void setDebugValueUndef() {
assert(isDebugValue() && "Must be a debug value instruction.");
for (MachineOperand &MO : debug_operands()) {
if (MO.isReg()) {
MO.setReg(0);
MO.setSubReg(0);
}
}
}
private:
/// If this instruction is embedded into a MachineFunction, return the
/// MachineRegisterInfo object for the current function, otherwise
/// return null.
MachineRegisterInfo *getRegInfo();
/// Unlink all of the register operands in this instruction from their
/// respective use lists. This requires that the operands already be on their
/// use lists.
void removeRegOperandsFromUseLists(MachineRegisterInfo&);
/// Add all of the register operands in this instruction from their
/// respective use lists. This requires that the operands not be on their
/// use lists yet.
void addRegOperandsToUseLists(MachineRegisterInfo&);
/// Slow path for hasProperty when we're dealing with a bundle.
bool hasPropertyInBundle(uint64_t Mask, QueryType Type) const;
/// Implements the logic of getRegClassConstraintEffectForVReg for the
/// this MI and the given operand index \p OpIdx.
/// If the related operand does not constrained Reg, this returns CurRC.
const TargetRegisterClass *getRegClassConstraintEffectForVRegImpl(
unsigned OpIdx, Register Reg, const TargetRegisterClass *CurRC,
const TargetInstrInfo *TII, const TargetRegisterInfo *TRI) const;
/// Stores extra instruction information inline or allocates as ExtraInfo
/// based on the number of pointers.
void setExtraInfo(MachineFunction &MF, ArrayRef<MachineMemOperand *> MMOs,
MCSymbol *PreInstrSymbol, MCSymbol *PostInstrSymbol,
MDNode *HeapAllocMarker, MDNode *PCSections,
uint32_t CFIType);
};
/// Special DenseMapInfo traits to compare MachineInstr* by *value* of the
/// instruction rather than by pointer value.
/// The hashing and equality testing functions ignore definitions so this is
/// useful for CSE, etc.
struct MachineInstrExpressionTrait : DenseMapInfo<MachineInstr*> {
static inline MachineInstr *getEmptyKey() {
return nullptr;
}
static inline MachineInstr *getTombstoneKey() {
return reinterpret_cast<MachineInstr*>(-1);
}
static unsigned getHashValue(const MachineInstr* const &MI);
static bool isEqual(const MachineInstr* const &LHS,
const MachineInstr* const &RHS) {
if (RHS == getEmptyKey() || RHS == getTombstoneKey() ||
LHS == getEmptyKey() || LHS == getTombstoneKey())
return LHS == RHS;
return LHS->isIdenticalTo(*RHS, MachineInstr::IgnoreVRegDefs);
}
};
//===----------------------------------------------------------------------===//
// Debugging Support
inline raw_ostream& operator<<(raw_ostream &OS, const MachineInstr &MI) {
MI.print(OS);
return OS;
}
} // end namespace llvm
#endif // LLVM_CODEGEN_MACHINEINSTR_H