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//===-- PPCInstrInfo.h - PowerPC Instruction Information --------*- C++ -*-===//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
// This file contains the PowerPC implementation of the TargetInstrInfo class.
#include "PPCRegisterInfo.h"
#include "llvm/CodeGen/TargetInstrInfo.h"
#include ""
namespace llvm {
/// PPCII - This namespace holds all of the PowerPC target-specific
/// per-instruction flags. These must match the corresponding definitions in
/// and
namespace PPCII {
enum {
// PPC970 Instruction Flags. These flags describe the characteristics of the
// PowerPC 970 (aka G5) dispatch groups and how they are formed out of
// raw machine instructions.
/// PPC970_First - This instruction starts a new dispatch group, so it will
/// always be the first one in the group.
PPC970_First = 0x1,
/// PPC970_Single - This instruction starts a new dispatch group and
/// terminates it, so it will be the sole instruction in the group.
PPC970_Single = 0x2,
/// PPC970_Cracked - This instruction is cracked into two pieces, requiring
/// two dispatch pipes to be available to issue.
PPC970_Cracked = 0x4,
/// PPC970_Mask/Shift - This is a bitmask that selects the pipeline type that
/// an instruction is issued to.
PPC970_Shift = 3,
PPC970_Mask = 0x07 << PPC970_Shift
enum PPC970_Unit {
/// These are the various PPC970 execution unit pipelines. Each instruction
/// is one of these.
PPC970_Pseudo = 0 << PPC970_Shift, // Pseudo instruction
PPC970_FXU = 1 << PPC970_Shift, // Fixed Point (aka Integer/ALU) Unit
PPC970_LSU = 2 << PPC970_Shift, // Load Store Unit
PPC970_FPU = 3 << PPC970_Shift, // Floating Point Unit
PPC970_CRU = 4 << PPC970_Shift, // Control Register Unit
PPC970_VALU = 5 << PPC970_Shift, // Vector ALU
PPC970_VPERM = 6 << PPC970_Shift, // Vector Permute Unit
PPC970_BRU = 7 << PPC970_Shift // Branch Unit
enum {
/// Shift count to bypass PPC970 flags
NewDef_Shift = 6,
/// This instruction is an X-Form memory operation.
XFormMemOp = 0x1 << (NewDef_Shift+1)
} // end namespace PPCII
// Instructions that have an immediate form might be convertible to that
// form if the correct input is a result of a load immediate. In order to
// know whether the transformation is special, we might need to know some
// of the details of the two forms.
struct ImmInstrInfo {
// Is the immediate field in the immediate form signed or unsigned?
uint64_t SignedImm : 1;
// Does the immediate need to be a multiple of some value?
uint64_t ImmMustBeMultipleOf : 5;
// Is R0/X0 treated specially by the original r+r instruction?
// If so, in which operand?
uint64_t ZeroIsSpecialOrig : 3;
// Is R0/X0 treated specially by the new r+i instruction?
// If so, in which operand?
uint64_t ZeroIsSpecialNew : 3;
// Is the operation commutative?
uint64_t IsCommutative : 1;
// The operand number to check for add-immediate def.
uint64_t OpNoForForwarding : 3;
// The operand number for the immediate.
uint64_t ImmOpNo : 3;
// The opcode of the new instruction.
uint64_t ImmOpcode : 16;
// The size of the immediate.
uint64_t ImmWidth : 5;
// The immediate should be truncated to N bits.
uint64_t TruncateImmTo : 5;
// Is the instruction summing the operand
uint64_t IsSummingOperands : 1;
// Information required to convert an instruction to just a materialized
// immediate.
struct LoadImmediateInfo {
unsigned Imm : 16;
unsigned Is64Bit : 1;
unsigned SetCR : 1;
class PPCSubtarget;
class PPCInstrInfo : public PPCGenInstrInfo {
PPCSubtarget &Subtarget;
const PPCRegisterInfo RI;
void StoreRegToStackSlot(MachineFunction &MF, unsigned SrcReg, bool isKill,
int FrameIdx, const TargetRegisterClass *RC,
SmallVectorImpl<MachineInstr *> &NewMIs) const;
void LoadRegFromStackSlot(MachineFunction &MF, const DebugLoc &DL,
unsigned DestReg, int FrameIdx,
const TargetRegisterClass *RC,
SmallVectorImpl<MachineInstr *> &NewMIs) const;
// If the inst has imm-form and one of its operand is produced by a LI,
// put the imm into the inst directly and remove the LI if possible.
bool transformToImmFormFedByLI(MachineInstr &MI, const ImmInstrInfo &III,
unsigned ConstantOpNo, MachineInstr &DefMI,
int64_t Imm) const;
// If the inst has imm-form and one of its operand is produced by an
// add-immediate, try to transform it when possible.
bool transformToImmFormFedByAdd(MachineInstr &MI, const ImmInstrInfo &III,
unsigned ConstantOpNo, MachineInstr &DefMI,
bool KillDefMI) const;
// Try to find that, if the instruction 'MI' contains any operand that
// could be forwarded from some inst that feeds it. If yes, return the
// Def of that operand. And OpNoForForwarding is the operand index in
// the 'MI' for that 'Def'. If we see another use of this Def between
// the Def and the MI, SeenIntermediateUse becomes 'true'.
MachineInstr *getForwardingDefMI(MachineInstr &MI,
unsigned &OpNoForForwarding,
bool &SeenIntermediateUse) const;
// Can the user MI have it's source at index \p OpNoForForwarding
// forwarded from an add-immediate that feeds it?
bool isUseMIElgibleForForwarding(MachineInstr &MI, const ImmInstrInfo &III,
unsigned OpNoForForwarding) const;
bool isDefMIElgibleForForwarding(MachineInstr &DefMI,
const ImmInstrInfo &III,
MachineOperand *&ImmMO,
MachineOperand *&RegMO) const;
bool isImmElgibleForForwarding(const MachineOperand &ImmMO,
const MachineInstr &DefMI,
const ImmInstrInfo &III,
int64_t &Imm) const;
bool isRegElgibleForForwarding(const MachineOperand &RegMO,
const MachineInstr &DefMI,
const MachineInstr &MI, bool KillDefMI,
bool &IsFwdFeederRegKilled) const;
const unsigned *getStoreOpcodesForSpillArray() const;
const unsigned *getLoadOpcodesForSpillArray() const;
virtual void anchor();
/// Commutes the operands in the given instruction.
/// The commutable operands are specified by their indices OpIdx1 and OpIdx2.
/// Do not call this method for a non-commutable instruction or for
/// non-commutable pair of operand indices OpIdx1 and OpIdx2.
/// Even though the instruction is commutable, the method may still
/// fail to commute the operands, null pointer is returned in such cases.
/// For example, we can commute rlwimi instructions, but only if the
/// rotate amt is zero. We also have to munge the immediates a bit.
MachineInstr *commuteInstructionImpl(MachineInstr &MI, bool NewMI,
unsigned OpIdx1,
unsigned OpIdx2) const override;
explicit PPCInstrInfo(PPCSubtarget &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 PPCRegisterInfo &getRegisterInfo() const { return RI; }
bool isXFormMemOp(unsigned Opcode) const {
return get(Opcode).TSFlags & PPCII::XFormMemOp;
static bool isSameClassPhysRegCopy(unsigned Opcode) {
unsigned CopyOpcodes[] =
for (int i = 0; CopyOpcodes[i] != -1U; i++)
if (Opcode == CopyOpcodes[i])
return true;
return false;
ScheduleHazardRecognizer *
CreateTargetHazardRecognizer(const TargetSubtargetInfo *STI,
const ScheduleDAG *DAG) const override;
ScheduleHazardRecognizer *
CreateTargetPostRAHazardRecognizer(const InstrItineraryData *II,
const ScheduleDAG *DAG) const override;
unsigned getInstrLatency(const InstrItineraryData *ItinData,
const MachineInstr &MI,
unsigned *PredCost = nullptr) const override;
int getOperandLatency(const InstrItineraryData *ItinData,
const MachineInstr &DefMI, unsigned DefIdx,
const MachineInstr &UseMI,
unsigned UseIdx) const override;
int getOperandLatency(const InstrItineraryData *ItinData,
SDNode *DefNode, unsigned DefIdx,
SDNode *UseNode, unsigned UseIdx) const override {
return PPCGenInstrInfo::getOperandLatency(ItinData, DefNode, DefIdx,
UseNode, UseIdx);
bool hasLowDefLatency(const TargetSchedModel &SchedModel,
const MachineInstr &DefMI,
unsigned DefIdx) const override {
// Machine LICM should hoist all instructions in low-register-pressure
// situations; none are sufficiently free to justify leaving in a loop
// body.
return false;
bool useMachineCombiner() const override {
return true;
/// Return true when there is potentially a faster code sequence
/// for an instruction chain ending in <Root>. All potential patterns are
/// output in the <Pattern> array.
bool getMachineCombinerPatterns(
MachineInstr &Root,
SmallVectorImpl<MachineCombinerPattern> &P) const override;
bool isAssociativeAndCommutative(const MachineInstr &Inst) const override;
bool isCoalescableExtInstr(const MachineInstr &MI,
unsigned &SrcReg, unsigned &DstReg,
unsigned &SubIdx) const override;
unsigned isLoadFromStackSlot(const MachineInstr &MI,
int &FrameIndex) const override;
bool isReallyTriviallyReMaterializable(const MachineInstr &MI,
AAResults *AA) const override;
unsigned isStoreToStackSlot(const MachineInstr &MI,
int &FrameIndex) const override;
bool findCommutedOpIndices(const MachineInstr &MI, unsigned &SrcOpIdx1,
unsigned &SrcOpIdx2) const override;
void insertNoop(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI) const override;
// Branch analysis.
bool analyzeBranch(MachineBasicBlock &MBB, MachineBasicBlock *&TBB,
MachineBasicBlock *&FBB,
SmallVectorImpl<MachineOperand> &Cond,
bool AllowModify) 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;
// Select analysis.
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 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;
unsigned getStoreOpcodeForSpill(unsigned Reg,
const TargetRegisterClass *RC = nullptr) const;
unsigned getLoadOpcodeForSpill(unsigned Reg,
const TargetRegisterClass *RC = nullptr) const;
reverseBranchCondition(SmallVectorImpl<MachineOperand> &Cond) const override;
bool FoldImmediate(MachineInstr &UseMI, MachineInstr &DefMI, unsigned Reg,
MachineRegisterInfo *MRI) const override;
// If conversion by predication (only supported by some branch instructions).
// All of the profitability checks always return true; it is always
// profitable to use the predicated branches.
bool isProfitableToIfCvt(MachineBasicBlock &MBB,
unsigned NumCycles, unsigned ExtraPredCycles,
BranchProbability Probability) const override {
return true;
bool isProfitableToIfCvt(MachineBasicBlock &TMBB,
unsigned NumT, unsigned ExtraT,
MachineBasicBlock &FMBB,
unsigned NumF, unsigned ExtraF,
BranchProbability Probability) const override;
bool isProfitableToDupForIfCvt(MachineBasicBlock &MBB, unsigned NumCycles,
BranchProbability Probability) const override {
return true;
bool isProfitableToUnpredicate(MachineBasicBlock &TMBB,
MachineBasicBlock &FMBB) const override {
return false;
// Predication support.
bool isPredicated(const MachineInstr &MI) const override;
bool isUnpredicatedTerminator(const MachineInstr &MI) const override;
bool PredicateInstruction(MachineInstr &MI,
ArrayRef<MachineOperand> Pred) const override;
bool SubsumesPredicate(ArrayRef<MachineOperand> Pred1,
ArrayRef<MachineOperand> Pred2) const override;
bool DefinesPredicate(MachineInstr &MI,
std::vector<MachineOperand> &Pred) const override;
bool isPredicable(const MachineInstr &MI) const override;
// Comparison optimization.
bool analyzeCompare(const MachineInstr &MI, unsigned &SrcReg,
unsigned &SrcReg2, int &Mask, int &Value) const override;
bool optimizeCompareInstr(MachineInstr &CmpInstr, unsigned SrcReg,
unsigned SrcReg2, int Mask, int Value,
const MachineRegisterInfo *MRI) const override;
/// Return true if get the base operand, byte offset of an instruction and
/// the memory width. Width is the size of memory that is being
/// loaded/stored (e.g. 1, 2, 4, 8).
bool getMemOperandWithOffsetWidth(const MachineInstr &LdSt,
const MachineOperand *&BaseOp,
int64_t &Offset, unsigned &Width,
const TargetRegisterInfo *TRI) const;
/// Return true if two MIs access different memory addresses and false
/// otherwise
areMemAccessesTriviallyDisjoint(const MachineInstr &MIa,
const MachineInstr &MIb) const override;
/// GetInstSize - Return the number of bytes of code the specified
/// instruction may be. This returns the maximum number of bytes.
unsigned getInstSizeInBytes(const MachineInstr &MI) const override;
void getNoop(MCInst &NopInst) 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;
// Expand VSX Memory Pseudo instruction to either a VSX or a FP instruction.
bool expandVSXMemPseudo(MachineInstr &MI) const;
// Lower pseudo instructions after register allocation.
bool expandPostRAPseudo(MachineInstr &MI) const override;
static bool isVFRegister(unsigned Reg) {
return Reg >= PPC::VF0 && Reg <= PPC::VF31;
static bool isVRRegister(unsigned Reg) {
return Reg >= PPC::V0 && Reg <= PPC::V31;
const TargetRegisterClass *updatedRC(const TargetRegisterClass *RC) const;
static int getRecordFormOpcode(unsigned Opcode);
bool isTOCSaveMI(const MachineInstr &MI) const;
bool isSignOrZeroExtended(const MachineInstr &MI, bool SignExt,
const unsigned PhiDepth) const;
/// Return true if the output of the instruction is always a sign-extended,
/// i.e. 0 to 31-th bits are same as 32-th bit.
bool isSignExtended(const MachineInstr &MI, const unsigned depth = 0) const {
return isSignOrZeroExtended(MI, true, depth);
/// Return true if the output of the instruction is always zero-extended,
/// i.e. 0 to 31-th bits are all zeros
bool isZeroExtended(const MachineInstr &MI, const unsigned depth = 0) const {
return isSignOrZeroExtended(MI, false, depth);
bool convertToImmediateForm(MachineInstr &MI,
MachineInstr **KilledDef = nullptr) const;
/// Fixup killed/dead flag for register \p RegNo between instructions [\p
/// StartMI, \p EndMI]. Some PostRA transformations may violate register
/// killed/dead flags semantics, this function can be called to fix up. Before
/// calling this function,
/// 1. Ensure that \p RegNo liveness is killed after instruction \p EndMI.
/// 2. Ensure that there is no new definition between (\p StartMI, \p EndMI)
/// and possible definition for \p RegNo is \p StartMI or \p EndMI.
/// 3. Ensure that all instructions between [\p StartMI, \p EndMI] are in same
/// basic block.
void fixupIsDeadOrKill(MachineInstr &StartMI, MachineInstr &EndMI,
unsigned RegNo) const;
void replaceInstrWithLI(MachineInstr &MI, const LoadImmediateInfo &LII) const;
void replaceInstrOperandWithImm(MachineInstr &MI, unsigned OpNo,
int64_t Imm) const;
bool instrHasImmForm(unsigned Opc, bool IsVFReg, ImmInstrInfo &III,
bool PostRA) const;
// In PostRA phase, try to find instruction defines \p Reg before \p MI.
// \p SeenIntermediate is set to true if uses between DefMI and \p MI exist.
MachineInstr *getDefMIPostRA(unsigned Reg, MachineInstr &MI,
bool &SeenIntermediateUse) const;
/// getRegNumForOperand - some operands use different numbering schemes
/// for the same registers. For example, a VSX instruction may have any of
/// vs0-vs63 allocated whereas an Altivec instruction could only have
/// vs32-vs63 allocated (numbered as v0-v31). This function returns the actual
/// register number needed for the opcode/operand number combination.
/// The operand number argument will be useful when we need to extend this
/// to instructions that use both Altivec and VSX numbering (for different
/// operands).
static unsigned getRegNumForOperand(const MCInstrDesc &Desc, unsigned Reg,
unsigned OpNo) {
int16_t regClass = Desc.OpInfo[OpNo].RegClass;
switch (regClass) {
// We store F0-F31, VF0-VF31 in MCOperand and it should be F0-F31,
// VSX32-VSX63 during encoding/disassembling
case PPC::VSSRCRegClassID:
case PPC::VSFRCRegClassID:
if (isVFRegister(Reg))
return PPC::VSX32 + (Reg - PPC::VF0);
// We store VSL0-VSL31, V0-V31 in MCOperand and it should be VSL0-VSL31,
// VSX32-VSX63 during encoding/disassembling
case PPC::VSRCRegClassID:
if (isVRRegister(Reg))
return PPC::VSX32 + (Reg - PPC::V0);
// Other RegClass doesn't need mapping
return Reg;
/// Check \p Opcode is BDNZ (Decrement CTR and branch if it is still nonzero).
bool isBDNZ(unsigned Opcode) const;
/// Find the hardware loop instruction used to set-up the specified loop.
/// On PPC, we have two instructions used to set-up the hardware loop
/// (MTCTRloop, MTCTR8loop) with corresponding endloop (BDNZ, BDNZ8)
/// instructions to indicate the end of a loop.
MachineInstr *
findLoopInstr(MachineBasicBlock &PreHeader,
SmallPtrSet<MachineBasicBlock *, 8> &Visited) const;
/// Analyze loop L, which must be a single-basic-block loop, and if the
/// conditions can be understood enough produce a PipelinerLoopInfo object.
analyzeLoopForPipelining(MachineBasicBlock *LoopBB) const override;