blob: 2f10bef1e47427d3482d7f835ae9206a35ddedfd [file] [log] [blame]
//===- AArch64InstrInfo.h - AArch64 Instruction Information -----*- 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 AArch64 implementation of the TargetInstrInfo class.
#include "AArch64.h"
#include "AArch64RegisterInfo.h"
#include "llvm/CodeGen/MachineCombinerPattern.h"
#include "llvm/CodeGen/TargetInstrInfo.h"
#include ""
namespace llvm {
class AArch64Subtarget;
class AArch64TargetMachine;
static const MachineMemOperand::Flags MOSuppressPair =
static const MachineMemOperand::Flags MOStridedAccess =
#define FALKOR_STRIDED_ACCESS_MD "falkor.strided.access"
class AArch64InstrInfo final : public AArch64GenInstrInfo {
const AArch64RegisterInfo RI;
const AArch64Subtarget &Subtarget;
explicit AArch64InstrInfo(const AArch64Subtarget &STI);
/// getRegisterInfo - TargetInstrInfo is a superset of MRegister info. As
/// such, whenever a client has an instance of instruction info, it should
/// always be able to get register info as well (through this method).
const AArch64RegisterInfo &getRegisterInfo() const { return RI; }
unsigned getInstSizeInBytes(const MachineInstr &MI) const override;
bool isAsCheapAsAMove(const MachineInstr &MI) const override;
bool isCoalescableExtInstr(const MachineInstr &MI, unsigned &SrcReg,
unsigned &DstReg, unsigned &SubIdx) const override;
areMemAccessesTriviallyDisjoint(MachineInstr &MIa, MachineInstr &MIb,
AliasAnalysis *AA = nullptr) const override;
unsigned isLoadFromStackSlot(const MachineInstr &MI,
int &FrameIndex) const override;
unsigned isStoreToStackSlot(const MachineInstr &MI,
int &FrameIndex) const override;
/// Returns true if there is a shiftable register and that the shift value
/// is non-zero.
bool hasShiftedReg(const MachineInstr &MI) const;
/// Returns true if there is an extendable register and that the extending
/// value is non-zero.
bool hasExtendedReg(const MachineInstr &MI) const;
/// \brief Does this instruction set its full destination register to zero?
bool isGPRZero(const MachineInstr &MI) const;
/// \brief Does this instruction rename a GPR without modifying bits?
bool isGPRCopy(const MachineInstr &MI) const;
/// \brief Does this instruction rename an FPR without modifying bits?
bool isFPRCopy(const MachineInstr &MI) const;
/// Return true if this is load/store scales or extends its register offset.
/// This refers to scaling a dynamic index as opposed to scaled immediates.
/// MI should be a memory op that allows scaled addressing.
bool isScaledAddr(const MachineInstr &MI) const;
/// Return true if pairing the given load or store is hinted to be
/// unprofitable.
bool isLdStPairSuppressed(const MachineInstr &MI) const;
/// Return true if the given load or store is a strided memory access.
bool isStridedAccess(const MachineInstr &MI) const;
/// Return true if this is an unscaled load/store.
bool isUnscaledLdSt(unsigned Opc) const;
/// Return true if this is an unscaled load/store.
bool isUnscaledLdSt(MachineInstr &MI) const;
static bool isPairableLdStInst(const MachineInstr &MI) {
switch (MI.getOpcode()) {
return false;
// Scaled instructions.
case AArch64::STRSui:
case AArch64::STRDui:
case AArch64::STRQui:
case AArch64::STRXui:
case AArch64::STRWui:
case AArch64::LDRSui:
case AArch64::LDRDui:
case AArch64::LDRQui:
case AArch64::LDRXui:
case AArch64::LDRWui:
case AArch64::LDRSWui:
// Unscaled instructions.
case AArch64::STURSi:
case AArch64::STURDi:
case AArch64::STURQi:
case AArch64::STURWi:
case AArch64::STURXi:
case AArch64::LDURSi:
case AArch64::LDURDi:
case AArch64::LDURQi:
case AArch64::LDURWi:
case AArch64::LDURXi:
case AArch64::LDURSWi:
return true;
/// \brief Return the opcode that set flags when possible. The caller is
/// responsible for ensuring the opc has a flag setting equivalent.
static unsigned convertToFlagSettingOpc(unsigned Opc, bool &Is64Bit) {
switch (Opc) {
llvm_unreachable("Opcode has no flag setting equivalent!");
// 32-bit cases:
case AArch64::ADDWri:
Is64Bit = false;
return AArch64::ADDSWri;
case AArch64::ADDWrr:
Is64Bit = false;
return AArch64::ADDSWrr;
case AArch64::ADDWrs:
Is64Bit = false;
return AArch64::ADDSWrs;
case AArch64::ADDWrx:
Is64Bit = false;
return AArch64::ADDSWrx;
case AArch64::ANDWri:
Is64Bit = false;
return AArch64::ANDSWri;
case AArch64::ANDWrr:
Is64Bit = false;
return AArch64::ANDSWrr;
case AArch64::ANDWrs:
Is64Bit = false;
return AArch64::ANDSWrs;
case AArch64::BICWrr:
Is64Bit = false;
return AArch64::BICSWrr;
case AArch64::BICWrs:
Is64Bit = false;
return AArch64::BICSWrs;
case AArch64::SUBWri:
Is64Bit = false;
return AArch64::SUBSWri;
case AArch64::SUBWrr:
Is64Bit = false;
return AArch64::SUBSWrr;
case AArch64::SUBWrs:
Is64Bit = false;
return AArch64::SUBSWrs;
case AArch64::SUBWrx:
Is64Bit = false;
return AArch64::SUBSWrx;
// 64-bit cases:
case AArch64::ADDXri:
Is64Bit = true;
return AArch64::ADDSXri;
case AArch64::ADDXrr:
Is64Bit = true;
return AArch64::ADDSXrr;
case AArch64::ADDXrs:
Is64Bit = true;
return AArch64::ADDSXrs;
case AArch64::ADDXrx:
Is64Bit = true;
return AArch64::ADDSXrx;
case AArch64::ANDXri:
Is64Bit = true;
return AArch64::ANDSXri;
case AArch64::ANDXrr:
Is64Bit = true;
return AArch64::ANDSXrr;
case AArch64::ANDXrs:
Is64Bit = true;
return AArch64::ANDSXrs;
case AArch64::BICXrr:
Is64Bit = true;
return AArch64::BICSXrr;
case AArch64::BICXrs:
Is64Bit = true;
return AArch64::BICSXrs;
case AArch64::SUBXri:
Is64Bit = true;
return AArch64::SUBSXri;
case AArch64::SUBXrr:
Is64Bit = true;
return AArch64::SUBSXrr;
case AArch64::SUBXrs:
Is64Bit = true;
return AArch64::SUBSXrs;
case AArch64::SUBXrx:
Is64Bit = true;
return AArch64::SUBSXrx;
/// Return true if this is a load/store that can be potentially paired/merged.
bool isCandidateToMergeOrPair(MachineInstr &MI) const;
/// Hint that pairing the given load or store is unprofitable.
void suppressLdStPair(MachineInstr &MI) const;
bool getMemOpBaseRegImmOfs(MachineInstr &LdSt, unsigned &BaseReg,
int64_t &Offset,
const TargetRegisterInfo *TRI) const override;
bool getMemOpBaseRegImmOfsWidth(MachineInstr &LdSt, unsigned &BaseReg,
int64_t &Offset, unsigned &Width,
const TargetRegisterInfo *TRI) const;
/// Return the immediate offset of the base register in a load/store \p LdSt.
MachineOperand &getMemOpBaseRegImmOfsOffsetOperand(MachineInstr &LdSt) const;
/// \brief Returns true if opcode \p Opc is a memory operation. If it is, set
/// \p Scale, \p Width, \p MinOffset, and \p MaxOffset accordingly.
/// For unscaled instructions, \p Scale is set to 1.
bool getMemOpInfo(unsigned Opcode, unsigned &Scale, unsigned &Width,
int64_t &MinOffset, int64_t &MaxOffset) const;
bool shouldClusterMemOps(MachineInstr &FirstLdSt, unsigned BaseReg1,
MachineInstr &SecondLdSt, unsigned BaseReg2,
unsigned NumLoads) const override;
void copyPhysRegTuple(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
const DebugLoc &DL, unsigned DestReg, unsigned SrcReg,
bool KillSrc, unsigned Opcode,
llvm::ArrayRef<unsigned> Indices) const;
void copyPhysReg(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
const DebugLoc &DL, unsigned DestReg, unsigned SrcReg,
bool KillSrc) const override;
void storeRegToStackSlot(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MBBI, unsigned SrcReg,
bool isKill, int FrameIndex,
const TargetRegisterClass *RC,
const TargetRegisterInfo *TRI) const override;
void loadRegFromStackSlot(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MBBI, unsigned DestReg,
int FrameIndex, const TargetRegisterClass *RC,
const TargetRegisterInfo *TRI) const override;
// This tells target independent code that it is okay to pass instructions
// with subreg operands to foldMemoryOperandImpl.
bool isSubregFoldable() const override { return true; }
using TargetInstrInfo::foldMemoryOperandImpl;
MachineInstr *
foldMemoryOperandImpl(MachineFunction &MF, MachineInstr &MI,
ArrayRef<unsigned> Ops,
MachineBasicBlock::iterator InsertPt, int FrameIndex,
LiveIntervals *LIS = nullptr) const override;
/// \returns true if a branch from an instruction with opcode \p BranchOpc
/// bytes is capable of jumping to a position \p BrOffset bytes away.
bool isBranchOffsetInRange(unsigned BranchOpc,
int64_t BrOffset) const override;
MachineBasicBlock *getBranchDestBlock(const MachineInstr &MI) const override;
bool analyzeBranch(MachineBasicBlock &MBB, MachineBasicBlock *&TBB,
MachineBasicBlock *&FBB,
SmallVectorImpl<MachineOperand> &Cond,
bool AllowModify = false) const override;
unsigned removeBranch(MachineBasicBlock &MBB,
int *BytesRemoved = nullptr) const override;
unsigned insertBranch(MachineBasicBlock &MBB, MachineBasicBlock *TBB,
MachineBasicBlock *FBB, ArrayRef<MachineOperand> Cond,
const DebugLoc &DL,
int *BytesAdded = nullptr) const override;
reverseBranchCondition(SmallVectorImpl<MachineOperand> &Cond) const override;
bool canInsertSelect(const MachineBasicBlock &, ArrayRef<MachineOperand> Cond,
unsigned, unsigned, int &, int &, int &) const override;
void insertSelect(MachineBasicBlock &MBB, MachineBasicBlock::iterator MI,
const DebugLoc &DL, unsigned DstReg,
ArrayRef<MachineOperand> Cond, unsigned TrueReg,
unsigned FalseReg) const override;
void getNoop(MCInst &NopInst) const override;
/// analyzeCompare - For a comparison instruction, return the source registers
/// in SrcReg and SrcReg2, and the value it compares against in CmpValue.
/// Return true if the comparison instruction can be analyzed.
bool analyzeCompare(const MachineInstr &MI, unsigned &SrcReg,
unsigned &SrcReg2, int &CmpMask,
int &CmpValue) const override;
/// optimizeCompareInstr - Convert the instruction supplying the argument to
/// the comparison into one that sets the zero bit in the flags register.
bool optimizeCompareInstr(MachineInstr &CmpInstr, unsigned SrcReg,
unsigned SrcReg2, int CmpMask, int CmpValue,
const MachineRegisterInfo *MRI) const override;
bool optimizeCondBranch(MachineInstr &MI) const override;
/// Return true when a code sequence can improve throughput. It
/// should be called only for instructions in loops.
/// \param Pattern - combiner pattern
bool isThroughputPattern(MachineCombinerPattern Pattern) const override;
/// Return true when there is potentially a faster code sequence
/// for an instruction chain ending in ``Root``. All potential patterns are
/// listed in the ``Patterns`` array.
bool getMachineCombinerPatterns(
MachineInstr &Root,
SmallVectorImpl<MachineCombinerPattern> &Patterns) const override;
/// Return true when Inst is associative and commutative so that it can be
/// reassociated.
bool isAssociativeAndCommutative(const MachineInstr &Inst) const override;
/// When getMachineCombinerPatterns() finds patterns, this function generates
/// the instructions that could replace the original code sequence
void genAlternativeCodeSequence(
MachineInstr &Root, MachineCombinerPattern Pattern,
SmallVectorImpl<MachineInstr *> &InsInstrs,
SmallVectorImpl<MachineInstr *> &DelInstrs,
DenseMap<unsigned, unsigned> &InstrIdxForVirtReg) const override;
/// AArch64 supports MachineCombiner.
bool useMachineCombiner() const override;
bool expandPostRAPseudo(MachineInstr &MI) const override;
std::pair<unsigned, unsigned>
decomposeMachineOperandsTargetFlags(unsigned TF) const override;
ArrayRef<std::pair<unsigned, const char *>>
getSerializableDirectMachineOperandTargetFlags() const override;
ArrayRef<std::pair<unsigned, const char *>>
getSerializableBitmaskMachineOperandTargetFlags() const override;
ArrayRef<std::pair<MachineMemOperand::Flags, const char *>>
getSerializableMachineMemOperandTargetFlags() const override;
canOutlineWithoutLRSave(MachineBasicBlock::iterator &CallInsertionPt) const;
bool isFunctionSafeToOutlineFrom(MachineFunction &MF,
bool OutlineFromLinkOnceODRs) const override;
MachineOutlinerInfo getOutlininingCandidateInfo(
std::pair<MachineBasicBlock::iterator, MachineBasicBlock::iterator>>
&RepeatedSequenceLocs) const override;
getOutliningType(MachineInstr &MI) const override;
void insertOutlinerEpilogue(MachineBasicBlock &MBB, MachineFunction &MF,
const MachineOutlinerInfo &MInfo) const override;
void insertOutlinerPrologue(MachineBasicBlock &MBB, MachineFunction &MF,
const MachineOutlinerInfo &MInfo) const override;
insertOutlinedCall(Module &M, MachineBasicBlock &MBB,
MachineBasicBlock::iterator &It, MachineFunction &MF,
const MachineOutlinerInfo &MInfo) const override;
/// Returns true if the instruction has a shift left that can be executed
/// more efficiently.
bool isExynosShiftLeftFast(const MachineInstr &MI) const;
/// Returns true if the instruction has a shift by immediate that can be
/// executed in one cycle less.
bool isFalkorShiftExtFast(const MachineInstr &MI) const;
/// \brief Sets the offsets on outlined instructions in \p MBB which use SP
/// so that they will be valid post-outlining.
/// \param MBB A \p MachineBasicBlock in an outlined function.
void fixupPostOutline(MachineBasicBlock &MBB) const;
void instantiateCondBranch(MachineBasicBlock &MBB, const DebugLoc &DL,
MachineBasicBlock *TBB,
ArrayRef<MachineOperand> Cond) const;
bool substituteCmpToZero(MachineInstr &CmpInstr, unsigned SrcReg,
const MachineRegisterInfo *MRI) const;
/// emitFrameOffset - Emit instructions as needed to set DestReg to SrcReg
/// plus Offset. This is intended to be used from within the prolog/epilog
/// insertion (PEI) pass, where a virtual scratch register may be allocated
/// if necessary, to be replaced by the scavenger at the end of PEI.
void emitFrameOffset(MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI,
const DebugLoc &DL, unsigned DestReg, unsigned SrcReg,
int Offset, const TargetInstrInfo *TII,
MachineInstr::MIFlag = MachineInstr::NoFlags,
bool SetNZCV = false);
/// rewriteAArch64FrameIndex - Rewrite MI to access 'Offset' bytes from the
/// FP. Return false if the offset could not be handled directly in MI, and
/// return the left-over portion by reference.
bool rewriteAArch64FrameIndex(MachineInstr &MI, unsigned FrameRegIdx,
unsigned FrameReg, int &Offset,
const AArch64InstrInfo *TII);
/// \brief Use to report the frame offset status in isAArch64FrameOffsetLegal.
enum AArch64FrameOffsetStatus {
AArch64FrameOffsetCannotUpdate = 0x0, ///< Offset cannot apply.
AArch64FrameOffsetIsLegal = 0x1, ///< Offset is legal.
AArch64FrameOffsetCanUpdate = 0x2 ///< Offset can apply, at least partly.
/// \brief Check if the @p Offset is a valid frame offset for @p MI.
/// The returned value reports the validity of the frame offset for @p MI.
/// It uses the values defined by AArch64FrameOffsetStatus for that.
/// If result == AArch64FrameOffsetCannotUpdate, @p MI cannot be updated to
/// use an offset.eq
/// If result & AArch64FrameOffsetIsLegal, @p Offset can completely be
/// rewritten in @p MI.
/// If result & AArch64FrameOffsetCanUpdate, @p Offset contains the
/// amount that is off the limit of the legal offset.
/// If set, @p OutUseUnscaledOp will contain the whether @p MI should be
/// turned into an unscaled operator, which opcode is in @p OutUnscaledOp.
/// If set, @p EmittableOffset contains the amount that can be set in @p MI
/// (possibly with @p OutUnscaledOp if OutUseUnscaledOp is true) and that
/// is a legal offset.
int isAArch64FrameOffsetLegal(const MachineInstr &MI, int &Offset,
bool *OutUseUnscaledOp = nullptr,
unsigned *OutUnscaledOp = nullptr,
int *EmittableOffset = nullptr);
static inline bool isUncondBranchOpcode(int Opc) { return Opc == AArch64::B; }
static inline bool isCondBranchOpcode(int Opc) {
switch (Opc) {
case AArch64::Bcc:
case AArch64::CBZW:
case AArch64::CBZX:
case AArch64::CBNZW:
case AArch64::CBNZX:
case AArch64::TBZW:
case AArch64::TBZX:
case AArch64::TBNZW:
case AArch64::TBNZX:
return true;
return false;
static inline bool isIndirectBranchOpcode(int Opc) {
return Opc == AArch64::BR;
} // end namespace llvm