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llvm-mirror/include/llvm/CodeGen/MachineInstr.h
Jakob Stoklund Olesen 9d2c118af7 Remove dead function.
llvm-svn: 185731
2013-07-05 23:04:55 +00:00

1072 lines
44 KiB
C++

//===-- llvm/CodeGen/MachineInstr.h - MachineInstr 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 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/ArrayRef.h"
#include "llvm/ADT/DenseMapInfo.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/ilist.h"
#include "llvm/ADT/ilist_node.h"
#include "llvm/CodeGen/MachineOperand.h"
#include "llvm/IR/InlineAsm.h"
#include "llvm/MC/MCInstrDesc.h"
#include "llvm/Support/ArrayRecycler.h"
#include "llvm/Support/DebugLoc.h"
#include "llvm/Target/TargetOpcodes.h"
#include <vector>
namespace llvm {
template <typename T> class SmallVectorImpl;
class AliasAnalysis;
class TargetInstrInfo;
class TargetRegisterClass;
class TargetRegisterInfo;
class MachineFunction;
class MachineMemOperand;
//===----------------------------------------------------------------------===//
/// MachineInstr - 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<MachineInstr> {
public:
typedef MachineMemOperand **mmo_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
};
enum MIFlag {
NoFlags = 0,
FrameSetup = 1 << 0, // Instruction is used as a part of
// function frame setup code.
BundledPred = 1 << 1, // Instruction has bundled predecessors.
BundledSucc = 1 << 2 // Instruction has bundled successors.
};
private:
const MCInstrDesc *MCID; // Instruction descriptor.
MachineBasicBlock *Parent; // Pointer to the owning basic block.
// Operands are allocated by an ArrayRecycler.
MachineOperand *Operands; // Pointer to the first operand.
unsigned NumOperands; // Number of operands on instruction.
typedef ArrayRecycler<MachineOperand>::Capacity OperandCapacity;
OperandCapacity CapOperands; // Capacity of the Operands array.
uint8_t Flags; // Various bits of additional
// information about machine
// instruction.
uint8_t AsmPrinterFlags; // 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.
uint8_t NumMemRefs; // Information on memory references.
mmo_iterator MemRefs;
DebugLoc debugLoc; // Source line information.
MachineInstr(const MachineInstr&) LLVM_DELETED_FUNCTION;
void operator=(const MachineInstr&) LLVM_DELETED_FUNCTION;
// Use MachineFunction::DeleteMachineInstr() instead.
~MachineInstr() LLVM_DELETED_FUNCTION;
// Intrusive list support
friend struct ilist_traits<MachineInstr>;
friend struct ilist_traits<MachineBasicBlock>;
void setParent(MachineBasicBlock *P) { Parent = P; }
/// MachineInstr ctor - This constructor creates a copy of the given
/// MachineInstr in the given MachineFunction.
MachineInstr(MachineFunction &, const MachineInstr &);
/// MachineInstr ctor - 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 &MCID,
const DebugLoc dl, bool NoImp = false);
// MachineInstrs are pool-allocated and owned by MachineFunction.
friend class MachineFunction;
public:
const MachineBasicBlock* getParent() const { return Parent; }
MachineBasicBlock* getParent() { return Parent; }
/// getAsmPrinterFlags - Return the asm printer flags bitvector.
///
uint8_t getAsmPrinterFlags() const { return AsmPrinterFlags; }
/// clearAsmPrinterFlags - clear the AsmPrinter bitvector
///
void clearAsmPrinterFlags() { AsmPrinterFlags = 0; }
/// getAsmPrinterFlag - Return whether an AsmPrinter flag is set.
///
bool getAsmPrinterFlag(CommentFlag Flag) const {
return AsmPrinterFlags & Flag;
}
/// setAsmPrinterFlag - Set a flag for the AsmPrinter.
///
void setAsmPrinterFlag(CommentFlag Flag) {
AsmPrinterFlags |= (uint8_t)Flag;
}
/// clearAsmPrinterFlag - clear specific AsmPrinter flags
///
void clearAsmPrinterFlag(CommentFlag Flag) {
AsmPrinterFlags &= ~Flag;
}
/// getFlags - Return the MI flags bitvector.
uint8_t getFlags() const {
return Flags;
}
/// getFlag - Return whether an MI flag is set.
bool getFlag(MIFlag Flag) const {
return Flags & Flag;
}
/// setFlag - Set a MI flag.
void setFlag(MIFlag Flag) {
Flags |= (uint8_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 &= ~((uint8_t)Flag);
}
/// isInsideBundle - 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);
}
/// isBundled - 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();
/// getDebugLoc - Returns the debug location id of this MachineInstr.
///
DebugLoc getDebugLoc() const { return debugLoc; }
/// emitError - 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;
/// getDesc - Returns the target instruction descriptor of this
/// MachineInstr.
const MCInstrDesc &getDesc() const { return *MCID; }
/// getOpcode - Returns the opcode of this MachineInstr.
///
int getOpcode() const { return MCID->Opcode; }
/// Access to explicit operands of the instruction.
///
unsigned getNumOperands() const { return NumOperands; }
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];
}
/// getNumExplicitOperands - Returns the number of non-implicit operands.
///
unsigned getNumExplicitOperands() const;
/// iterator/begin/end - Iterate over all operands of a machine instruction.
typedef MachineOperand *mop_iterator;
typedef const MachineOperand *const_mop_iterator;
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; }
/// Access to memory operands of the instruction
mmo_iterator memoperands_begin() const { return MemRefs; }
mmo_iterator memoperands_end() const { return MemRefs + NumMemRefs; }
bool memoperands_empty() const { return NumMemRefs == 0; }
/// hasOneMemOperand - Return true if this instruction has exactly one
/// MachineMemOperand.
bool hasOneMemOperand() const {
return NumMemRefs == 1;
}
/// 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
};
/// hasProperty - 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 {
// Inline the fast path for unbundled or bundle-internal instructions.
if (Type == IgnoreBundle || !isBundled() || isBundledWithPred())
return getDesc().getFlags() & (1 << MCFlag);
// If this is the first instruction in a bundle, take the slow path.
return hasPropertyInBundle(1 << MCFlag, Type);
}
/// isVariadic - 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);
}
/// hasOptionalDef - 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);
}
/// isPseudo - 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);
}
bool isReturn(QueryType Type = AnyInBundle) const {
return hasProperty(MCID::Return, Type);
}
bool isCall(QueryType Type = AnyInBundle) const {
return hasProperty(MCID::Call, Type);
}
/// isBarrier - 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);
}
/// isTerminator - 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);
}
/// isBranch - 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);
}
/// isIndirectBranch - 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);
}
/// isConditionalBranch - 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);
}
/// isUnconditionalBranch - 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);
}
// isPredicable - 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);
}
/// isCompare - Return true if this instruction is a comparison.
bool isCompare(QueryType Type = IgnoreBundle) const {
return hasProperty(MCID::Compare, Type);
}
/// isMoveImmediate - Return true if this instruction is a move immediate
/// (including conditional moves) instruction.
bool isMoveImmediate(QueryType Type = IgnoreBundle) const {
return hasProperty(MCID::MoveImm, Type);
}
/// isBitcast - Return true if this instruction is a bitcast instruction.
///
bool isBitcast(QueryType Type = IgnoreBundle) const {
return hasProperty(MCID::Bitcast, Type);
}
/// isSelect - Return true if this instruction is a select instruction.
///
bool isSelect(QueryType Type = IgnoreBundle) const {
return hasProperty(MCID::Select, Type);
}
/// isNotDuplicable - 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 {
return hasProperty(MCID::NotDuplicable, Type);
}
/// hasDelaySlot - 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);
}
/// canFoldAsLoad - 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);
}
//===--------------------------------------------------------------------===//
// Side Effect Analysis
//===--------------------------------------------------------------------===//
/// mayLoad - 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);
}
/// mayStore - 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);
}
//===--------------------------------------------------------------------===//
// Flags that indicate whether an instruction can be modified by a method.
//===--------------------------------------------------------------------===//
/// isCommutable - 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);
}
/// isConvertibleTo3Addr - 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);
}
/// usesCustomInsertionHook - 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);
}
/// hasPostISelHook - 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);
}
/// isRematerializable - 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);
}
/// isAsCheapAsAMove - 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.
// FIXME: This probably requires a target hook.
return hasProperty(MCID::CheapAsAMove, Type);
}
/// hasExtraSrcRegAllocReq - 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);
}
/// hasExtraDefRegAllocReq - 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
};
/// isIdenticalTo - Return true if this instruction is identical to (same
/// opcode and same operands as) the specified instruction.
bool isIdenticalTo(const MachineInstr *Other,
MICheckType Check = CheckDefs) 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();
/// isLabel - Returns true if the MachineInstr represents a label.
///
bool isLabel() const {
return getOpcode() == TargetOpcode::PROLOG_LABEL ||
getOpcode() == TargetOpcode::EH_LABEL ||
getOpcode() == TargetOpcode::GC_LABEL;
}
bool isPrologLabel() const {
return getOpcode() == TargetOpcode::PROLOG_LABEL;
}
bool isEHLabel() const { return getOpcode() == TargetOpcode::EH_LABEL; }
bool isGCLabel() const { return getOpcode() == TargetOpcode::GC_LABEL; }
bool isDebugValue() const { return getOpcode() == TargetOpcode::DBG_VALUE; }
bool isPHI() const { return getOpcode() == TargetOpcode::PHI; }
bool isKill() const { return getOpcode() == TargetOpcode::KILL; }
bool isImplicitDef() const { return getOpcode()==TargetOpcode::IMPLICIT_DEF; }
bool isInlineAsm() const { return getOpcode() == TargetOpcode::INLINEASM; }
bool isMSInlineAsm() const {
return getOpcode() == TargetOpcode::INLINEASM && getInlineAsmDialect();
}
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();
}
/// isCopyLike - Return true if the instruction behaves like a copy.
/// This does not include native copy instructions.
bool isCopyLike() const {
return isCopy() || isSubregToReg();
}
/// isIdentityCopy - 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();
}
/// isTransient - 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 false;
// Copy-like instructions are usually eliminated during register allocation.
case TargetOpcode::PHI:
case TargetOpcode::COPY:
case TargetOpcode::INSERT_SUBREG:
case TargetOpcode::SUBREG_TO_REG:
case TargetOpcode::REG_SEQUENCE:
// Pseudo-instructions that don't produce any real output.
case TargetOpcode::IMPLICIT_DEF:
case TargetOpcode::KILL:
case TargetOpcode::PROLOG_LABEL:
case TargetOpcode::EH_LABEL:
case TargetOpcode::GC_LABEL:
case TargetOpcode::DBG_VALUE:
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;
/// readsRegister - 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(unsigned Reg, const TargetRegisterInfo *TRI = NULL) const {
return findRegisterUseOperandIdx(Reg, false, TRI) != -1;
}
/// readsVirtualRegister - 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(unsigned Reg) const {
return readsWritesVirtualRegister(Reg).first;
}
/// readsWritesVirtualRegister - 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(unsigned Reg,
SmallVectorImpl<unsigned> *Ops = 0) const;
/// killsRegister - 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(unsigned Reg, const TargetRegisterInfo *TRI = NULL) const {
return findRegisterUseOperandIdx(Reg, true, TRI) != -1;
}
/// definesRegister - 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(unsigned Reg, const TargetRegisterInfo *TRI=NULL) const {
return findRegisterDefOperandIdx(Reg, false, false, TRI) != -1;
}
/// modifiesRegister - 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(unsigned Reg, const TargetRegisterInfo *TRI) const {
return findRegisterDefOperandIdx(Reg, false, true, TRI) != -1;
}
/// registerDefIsDead - 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(unsigned Reg,
const TargetRegisterInfo *TRI = NULL) const {
return findRegisterDefOperandIdx(Reg, true, false, TRI) != -1;
}
/// findRegisterUseOperandIdx() - 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(unsigned Reg, bool isKill = false,
const TargetRegisterInfo *TRI = NULL) const;
/// findRegisterUseOperand - Wrapper for findRegisterUseOperandIdx, it returns
/// a pointer to the MachineOperand rather than an index.
MachineOperand *findRegisterUseOperand(unsigned Reg, bool isKill = false,
const TargetRegisterInfo *TRI = NULL) {
int Idx = findRegisterUseOperandIdx(Reg, isKill, TRI);
return (Idx == -1) ? NULL : &getOperand(Idx);
}
/// findRegisterDefOperandIdx() - 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(unsigned Reg,
bool isDead = false, bool Overlap = false,
const TargetRegisterInfo *TRI = NULL) const;
/// findRegisterDefOperand - Wrapper for findRegisterDefOperandIdx, it returns
/// a pointer to the MachineOperand rather than an index.
MachineOperand *findRegisterDefOperand(unsigned Reg, bool isDead = false,
const TargetRegisterInfo *TRI = NULL) {
int Idx = findRegisterDefOperandIdx(Reg, isDead, false, TRI);
return (Idx == -1) ? NULL : &getOperand(Idx);
}
/// findFirstPredOperandIdx() - 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;
/// findInlineAsmFlagIdx() - 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.
///
/// The flag operand is an immediate that can be decoded with methods like
/// InlineAsm::hasRegClassConstraint().
///
int findInlineAsmFlagIdx(unsigned OpIdx, unsigned *GroupNo = 0) const;
/// getRegClassConstraint - 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 classs constraint cannot be
/// determined.
///
const TargetRegisterClass*
getRegClassConstraint(unsigned OpIdx,
const TargetInstrInfo *TII,
const TargetRegisterInfo *TRI) const;
/// tieOperands - 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);
/// findTiedOperandIdx - 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;
/// isRegTiedToUseOperand - 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 = 0) const {
const MachineOperand &MO = getOperand(DefOpIdx);
if (!MO.isReg() || !MO.isDef() || !MO.isTied())
return false;
if (UseOpIdx)
*UseOpIdx = findTiedOperandIdx(DefOpIdx);
return true;
}
/// isRegTiedToDefOperand - Return true if the use operand of the specified
/// index is tied to an def operand. It also returns the def operand index by
/// reference if DefOpIdx is not null.
bool isRegTiedToDefOperand(unsigned UseOpIdx, unsigned *DefOpIdx = 0) const {
const MachineOperand &MO = getOperand(UseOpIdx);
if (!MO.isReg() || !MO.isUse() || !MO.isTied())
return false;
if (DefOpIdx)
*DefOpIdx = findTiedOperandIdx(UseOpIdx);
return true;
}
/// clearKillInfo - Clears kill flags on all operands.
///
void clearKillInfo();
/// substituteRegister - Replace all occurrences of FromReg with ToReg:SubIdx,
/// properly composing subreg indices where necessary.
void substituteRegister(unsigned FromReg, unsigned ToReg, unsigned SubIdx,
const TargetRegisterInfo &RegInfo);
/// addRegisterKilled - 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(unsigned IncomingReg,
const TargetRegisterInfo *RegInfo,
bool AddIfNotFound = false);
/// clearRegisterKills - Clear all kill flags affecting Reg. If RegInfo is
/// provided, this includes super-register kills.
void clearRegisterKills(unsigned Reg, const TargetRegisterInfo *RegInfo);
/// addRegisterDead - 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(unsigned IncomingReg, const TargetRegisterInfo *RegInfo,
bool AddIfNotFound = false);
/// addRegisterDefined - We have determined MI defines a register. Make sure
/// there is an operand defining Reg.
void addRegisterDefined(unsigned IncomingReg,
const TargetRegisterInfo *RegInfo = 0);
/// setPhysRegsDeadExcept - 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<unsigned> UsedRegs,
const TargetRegisterInfo &TRI);
/// isSafeToMove - 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(const TargetInstrInfo *TII, AliasAnalysis *AA,
bool &SawStore) const;
/// hasOrderedMemoryRef - 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;
/// isInvariantLoad - Return true if this instruction is loading from a
/// location whose value is invariant across the function. For example,
/// loading a value from the constant pool or from the argument area of
/// a function if it does not change. This should only return true of *all*
/// loads the instruction does are invariant (if it does multiple loads).
bool isInvariantLoad(AliasAnalysis *AA) const;
/// isConstantValuePHI - If the specified instruction is a PHI that always
/// merges together the same virtual register, return the register, otherwise
/// return 0.
unsigned isConstantValuePHI() const;
/// hasUnmodeledSideEffects - 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;
/// allDefsAreDead - Return true if all the defs of this instruction are dead.
///
bool allDefsAreDead() const;
/// copyImplicitOps - Copy implicit register operands from specified
/// instruction to this instruction.
void copyImplicitOps(MachineFunction &MF, const MachineInstr *MI);
//
// Debugging support
//
void print(raw_ostream &OS, const TargetMachine *TM = 0,
bool SkipOpers = false) const;
void dump() 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);
/// setDesc - Replace the instruction descriptor (thus opcode) of
/// the current instruction with a new one.
///
void setDesc(const MCInstrDesc &tid) { MCID = &tid; }
/// setDebugLoc - Replace current source information with new such.
/// Avoid using this, the constructor argument is preferable.
///
void setDebugLoc(const DebugLoc dl) { debugLoc = dl; }
/// RemoveOperand - Erase an operand from an instruction, leaving it with one
/// fewer operand than it started with.
///
void RemoveOperand(unsigned i);
/// addMemOperand - 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);
/// setMemRefs - Assign this MachineInstr's memory reference descriptor
/// list. This does not transfer ownership.
void setMemRefs(mmo_iterator NewMemRefs, mmo_iterator NewMemRefsEnd) {
MemRefs = NewMemRefs;
NumMemRefs = uint8_t(NewMemRefsEnd - NewMemRefs);
assert(NumMemRefs == NewMemRefsEnd - NewMemRefs && "Too many memrefs");
}
private:
/// getRegInfo - If this instruction is embedded into a MachineFunction,
/// return the MachineRegisterInfo object for the current function, otherwise
/// return null.
MachineRegisterInfo *getRegInfo();
/// untieRegOperand - 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;
}
}
/// addImplicitDefUseOperands - Add all implicit def and use operands to
/// this instruction.
void addImplicitDefUseOperands(MachineFunction &MF);
/// RemoveRegOperandsFromUseLists - 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&);
/// AddRegOperandsToUseLists - 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&);
/// hasPropertyInBundle - Slow path for hasProperty when we're dealing with a
/// bundle.
bool hasPropertyInBundle(unsigned Mask, QueryType Type) const;
};
/// MachineInstrExpressionTrait - 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 0;
}
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 llvm namespace
#endif