//===- HexagonMCInstrInfo.cpp - Utility functions on Hexagon MCInsts ------===//
//
// 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
//
//===----------------------------------------------------------------------===//
//
// Utility functions for Hexagon specific MCInst queries
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_LIB_TARGET_HEXAGON_MCTARGETDESC_HEXAGONMCINSTRINFO_H
#define LLVM_LIB_TARGET_HEXAGON_MCTARGETDESC_HEXAGONMCINSTRINFO_H

#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/iterator.h"
#include "llvm/ADT/iterator_range.h"
#include "llvm/MC/MCInst.h"
#include "llvm/Support/MathExtras.h"
#include <cstddef>
#include <cstdint>

namespace llvm {

class HexagonMCChecker;
class MCContext;
class MCExpr;
class MCInstrDesc;
class MCInstrInfo;
class MCRegisterInfo;
class MCSubtargetInfo;

class DuplexCandidate {
public:
  unsigned packetIndexI, packetIndexJ, iClass;

  DuplexCandidate(unsigned i, unsigned j, unsigned iClass)
      : packetIndexI(i), packetIndexJ(j), iClass(iClass) {}
};

namespace Hexagon {

class PacketIterator
    : public llvm::iterator_facade_base<
          PacketIterator, std::forward_iterator_tag, const MCInst> {
  MCInstrInfo const &MCII;
  MCInst::const_iterator BundleCurrent;
  MCInst::const_iterator BundleEnd;
  MCInst::const_iterator DuplexCurrent;
  MCInst::const_iterator DuplexEnd;

public:
  PacketIterator(MCInstrInfo const &MCII, MCInst const &Inst);
  PacketIterator(MCInstrInfo const &MCII, MCInst const &Inst, std::nullptr_t);

  PacketIterator &operator++();
  MCInst const &operator*() const;
  bool operator==(PacketIterator const &Other) const;
};

} // end namespace Hexagon

namespace HexagonMCInstrInfo {

constexpr size_t innerLoopOffset = 0;
constexpr int64_t innerLoopMask = 1 << innerLoopOffset;

constexpr size_t outerLoopOffset = 1;
constexpr int64_t outerLoopMask = 1 << outerLoopOffset;

// do not reorder memory load/stores by default load/stores are re-ordered
// and by default loads can be re-ordered
constexpr size_t memReorderDisabledOffset = 2;
constexpr int64_t memReorderDisabledMask = 1 << memReorderDisabledOffset;

constexpr size_t splitNoMemOrderOffset = 3;
constexpr int64_t splitNoMemorderMask = 1 << splitNoMemOrderOffset;

constexpr size_t noShuffleOffset = 4;
constexpr int64_t noShuffleMask = 1 << noShuffleOffset;

constexpr size_t bundleInstructionsOffset = 1;

void addConstant(MCInst &MI, uint64_t Value, MCContext &Context);
void addConstExtender(MCContext &Context, MCInstrInfo const &MCII, MCInst &MCB,
                      MCInst const &MCI);

// Returns a iterator range of instructions in this bundle
iterator_range<Hexagon::PacketIterator>
bundleInstructions(MCInstrInfo const &MCII, MCInst const &MCI);
iterator_range<MCInst::const_iterator> bundleInstructions(MCInst const &MCI);

// Returns the number of instructions in the bundle
size_t bundleSize(MCInst const &MCI);

// Put the packet in to canonical form, compound, duplex, pad, and shuffle
bool canonicalizePacket(MCInstrInfo const &MCII, MCSubtargetInfo const &STI,
                        MCContext &Context, MCInst &MCB,
                        HexagonMCChecker *Checker,
                        bool AttemptCompatibility = false);
bool IsABranchingInst(MCInstrInfo const &MCII, MCSubtargetInfo const &STI,
                      MCInst const &I);

// Create a duplex instruction given the two subinsts
MCInst *deriveDuplex(MCContext &Context, unsigned iClass, MCInst const &inst0,
                     MCInst const &inst1);
MCInst deriveExtender(MCInstrInfo const &MCII, MCInst const &Inst,
                      MCOperand const &MO);

// Convert this instruction in to a duplex subinst
MCInst deriveSubInst(MCInst const &Inst);

// Return the extender for instruction at Index or nullptr if none
MCInst const *extenderForIndex(MCInst const &MCB, size_t Index);
void extendIfNeeded(MCContext &Context, MCInstrInfo const &MCII, MCInst &MCB,
                    MCInst const &MCI);

// Return memory access size in bytes
unsigned getMemAccessSize(MCInstrInfo const &MCII, MCInst const &MCI);

// Return memory access size
unsigned getAddrMode(MCInstrInfo const &MCII, MCInst const &MCI);

MCInstrDesc const &getDesc(MCInstrInfo const &MCII, MCInst const &MCI);

// Return which duplex group this instruction belongs to
unsigned getDuplexCandidateGroup(MCInst const &MI);

// Return a list of all possible instruction duplex combinations
SmallVector<DuplexCandidate, 8>
getDuplexPossibilties(MCInstrInfo const &MCII, MCSubtargetInfo const &STI,
                      MCInst const &MCB);
unsigned getDuplexRegisterNumbering(unsigned Reg);

MCExpr const &getExpr(MCExpr const &Expr);

// Return the index of the extendable operand
unsigned short getExtendableOp(MCInstrInfo const &MCII, MCInst const &MCI);

// Return a reference to the extendable operand
MCOperand const &getExtendableOperand(MCInstrInfo const &MCII,
                                      MCInst const &MCI);

// Return the implicit alignment of the extendable operand
unsigned getExtentAlignment(MCInstrInfo const &MCII, MCInst const &MCI);

// Return the number of logical bits of the extendable operand
unsigned getExtentBits(MCInstrInfo const &MCII, MCInst const &MCI);

// Check if the extendable operand is signed.
bool isExtentSigned(MCInstrInfo const &MCII, MCInst const &MCI);

// Return the max value that a constant extendable operand can have
// without being extended.
int getMaxValue(MCInstrInfo const &MCII, MCInst const &MCI);

// Return the min value that a constant extendable operand can have
// without being extended.
int getMinValue(MCInstrInfo const &MCII, MCInst const &MCI);

// Return instruction name
StringRef getName(MCInstrInfo const &MCII, MCInst const &MCI);

// Return the operand index for the new value.
unsigned short getNewValueOp(MCInstrInfo const &MCII, MCInst const &MCI);

// Return the operand that consumes or produces a new value.
MCOperand const &getNewValueOperand(MCInstrInfo const &MCII, MCInst const &MCI);
unsigned short getNewValueOp2(MCInstrInfo const &MCII, MCInst const &MCI);
MCOperand const &getNewValueOperand2(MCInstrInfo const &MCII,
                                     MCInst const &MCI);

// Return the Hexagon ISA class for the insn.
unsigned getType(MCInstrInfo const &MCII, MCInst const &MCI);

/// Return the resources used by this instruction
unsigned getCVIResources(MCInstrInfo const &MCII,
                                      MCSubtargetInfo const &STI,
                                      MCInst const &MCI);

/// Return the slots used by the insn.
unsigned getUnits(MCInstrInfo const &MCII, MCSubtargetInfo const &STI,
                  MCInst const &MCI);
unsigned getOtherReservedSlots(MCInstrInfo const &MCII,
                               MCSubtargetInfo const &STI, MCInst const &MCI);
bool hasDuplex(MCInstrInfo const &MCII, MCInst const &MCI);

// Does the packet have an extender for the instruction at Index
bool hasExtenderForIndex(MCInst const &MCB, size_t Index);

bool hasImmExt(MCInst const &MCI);

// Return whether the instruction is a legal new-value producer.
bool hasNewValue(MCInstrInfo const &MCII, MCInst const &MCI);
bool hasNewValue2(MCInstrInfo const &MCII, MCInst const &MCI);
bool hasTmpDst(MCInstrInfo const &MCII, MCInst const &MCI);
bool hasHvxTmp(MCInstrInfo const &MCII, MCInst const &MCI);
unsigned iClassOfDuplexPair(unsigned Ga, unsigned Gb);

int64_t minConstant(MCInst const &MCI, size_t Index);
template <unsigned N, unsigned S>
bool inRange(MCInst const &MCI, size_t Index) {
  return isShiftedUInt<N, S>(minConstant(MCI, Index));
}
template <unsigned N, unsigned S>
bool inSRange(MCInst const &MCI, size_t Index) {
  return isShiftedInt<N, S>(minConstant(MCI, Index));
}
template <unsigned N> bool inRange(MCInst const &MCI, size_t Index) {
  return isUInt<N>(minConstant(MCI, Index));
}

// Return the instruction at Index
MCInst const &instruction(MCInst const &MCB, size_t Index);
bool isAccumulator(MCInstrInfo const &MCII, MCInst const &MCI);

// Returns whether this MCInst is a wellformed bundle
bool isBundle(MCInst const &MCI);

// Return whether the insn is an actual insn.
bool isCanon(MCInstrInfo const &MCII, MCInst const &MCI);
bool isCofMax1(MCInstrInfo const &MCII, MCInst const &MCI);
bool isCofRelax1(MCInstrInfo const &MCII, MCInst const &MCI);
bool isCofRelax2(MCInstrInfo const &MCII, MCInst const &MCI);
bool isCompound(MCInstrInfo const &MCII, MCInst const &MCI);

// Return whether the instruction needs to be constant extended.
bool isConstExtended(MCInstrInfo const &MCII, MCInst const &MCI);
bool isCVINew(MCInstrInfo const &MCII, MCInst const &MCI);

// Is this double register suitable for use in a duplex subinst
bool isDblRegForSubInst(unsigned Reg);

// Is this a duplex instruction
bool isDuplex(MCInstrInfo const &MCII, MCInst const &MCI);

// Can these instructions be duplexed
bool isDuplexPair(MCInst const &MIa, MCInst const &MIb);

// Can these duplex classes be combine in to a duplex instruction
bool isDuplexPairMatch(unsigned Ga, unsigned Gb);

// Return true if the insn may be extended based on the operand value.
bool isExtendable(MCInstrInfo const &MCII, MCInst const &MCI);

// Return whether the instruction must be always extended.
bool isExtended(MCInstrInfo const &MCII, MCInst const &MCI);

/// Return whether it is a floating-point insn.
bool isFloat(MCInstrInfo const &MCII, MCInst const &MCI);

bool isHVX(MCInstrInfo const &MCII, MCInst const &MCI);

// Returns whether this instruction is an immediate extender
bool isImmext(MCInst const &MCI);

// Returns whether this bundle is an endloop0
bool isInnerLoop(MCInst const &MCI);

// Is this an integer register
bool isIntReg(unsigned Reg);

// Is this register suitable for use in a duplex subinst
bool isIntRegForSubInst(unsigned Reg);
bool isMemReorderDisabled(MCInst const &MCI);

// Return whether the insn is a new-value consumer.
bool isNewValue(MCInstrInfo const &MCII, MCInst const &MCI);
/// Return true if the operand is a new-value store insn.
bool isNewValueStore(MCInstrInfo const &MCII, MCInst const &MCI);
bool isOpExtendable(MCInstrInfo const &MCII, MCInst const &MCI, unsigned short);

// Can these two instructions be duplexed
bool isOrderedDuplexPair(MCInstrInfo const &MCII, MCInst const &MIa,
                         bool ExtendedA, MCInst const &MIb, bool ExtendedB,
                         bool bisReversable, MCSubtargetInfo const &STI);

// Returns whether this bundle is an endloop1
bool isOuterLoop(MCInst const &MCI);

// Return whether this instruction is predicated
bool isPredicated(MCInstrInfo const &MCII, MCInst const &MCI);
bool isPredicateLate(MCInstrInfo const &MCII, MCInst const &MCI);
bool isPredicatedNew(MCInstrInfo const &MCII, MCInst const &MCI);

// Return whether the predicate sense is true
bool isPredicatedTrue(MCInstrInfo const &MCII, MCInst const &MCI);

// Return true if this is a scalar predicate register.
bool isPredReg(MCRegisterInfo const &MRI, unsigned Reg);

// Returns true if the Ith operand is a predicate register.
bool isPredRegister(MCInstrInfo const &MCII, MCInst const &Inst, unsigned I);

// Return whether the insn is a prefix.
bool isPrefix(MCInstrInfo const &MCII, MCInst const &MCI);

// Return whether the insn is solo, i.e., cannot be in a packet.
bool isSolo(MCInstrInfo const &MCII, MCInst const &MCI);

/// Return whether the insn can be packaged only with A and X-type insns.
bool isSoloAX(MCInstrInfo const &MCII, MCInst const &MCI);

/// Return whether the insn can be packaged only with an A-type insn in slot #1.
bool isRestrictSlot1AOK(MCInstrInfo const &MCII, MCInst const &MCI);
bool isRestrictNoSlot1Store(MCInstrInfo const &MCII, MCInst const &MCI);
bool isSubInstruction(MCInst const &MCI);
bool isVector(MCInstrInfo const &MCII, MCInst const &MCI);
bool mustExtend(MCExpr const &Expr);
bool mustNotExtend(MCExpr const &Expr);

// Returns true if this instruction requires a slot to execute.
bool requiresSlot(MCSubtargetInfo const &STI, MCInst const &MCI);


// Returns true if \a MCB would require endloop padding.
bool LoopNeedsPadding(MCInst const &MCB);

unsigned packetSize(StringRef CPU);

// Returns the maximum number of slots available in the given
// subtarget's packets.
unsigned packetSizeSlots(MCSubtargetInfo const &STI);

// Returns the number of slots consumed by this packet, considering duplexed
// and compound instructions.
unsigned slotsConsumed(MCInstrInfo const &MCII, MCSubtargetInfo const &STI,
                       MCInst const &MCI);

// Pad the bundle with nops to satisfy endloop requirements.
void padEndloop(MCInst &MCI, MCContext &Context);
class PredicateInfo {
public:
  PredicateInfo() : Register(0), Operand(0), PredicatedTrue(false) {}
  PredicateInfo(unsigned Register, unsigned Operand, bool PredicatedTrue)
      : Register(Register), Operand(Operand), PredicatedTrue(PredicatedTrue) {}
  bool isPredicated() const;
  unsigned Register;
  unsigned Operand;
  bool PredicatedTrue;
};
PredicateInfo predicateInfo(MCInstrInfo const &MCII, MCInst const &MCI);
bool prefersSlot3(MCInstrInfo const &MCII, MCInst const &MCI);

// Replace the instructions inside MCB, represented by Candidate
void replaceDuplex(MCContext &Context, MCInst &MCI, DuplexCandidate Candidate);

bool s27_2_reloc(MCExpr const &Expr);
// Marks a bundle as endloop0
void setInnerLoop(MCInst &MCI);
void setMemReorderDisabled(MCInst &MCI);
void setMustExtend(MCExpr const &Expr, bool Val = true);
void setMustNotExtend(MCExpr const &Expr, bool Val = true);
void setS27_2_reloc(MCExpr const &Expr, bool Val = true);

// Marks a bundle as endloop1
void setOuterLoop(MCInst &MCI);

// Would duplexing this instruction create a requirement to extend
bool subInstWouldBeExtended(MCInst const &potentialDuplex);
unsigned SubregisterBit(unsigned Consumer, unsigned Producer,
                        unsigned Producer2);

bool IsVecRegSingle(unsigned VecReg);
bool IsVecRegPair(unsigned VecReg);
bool IsReverseVecRegPair(unsigned VecReg);
bool IsSingleConsumerRefPairProducer(unsigned Producer, unsigned Consumer);

/// Returns an ordered pair of the constituent register ordinals for
/// each of the elements of \a VecRegPair.  For example, Hexagon::W0 ("v0:1")
/// returns { 0, 1 } and Hexagon::W1 ("v3:2") returns { 3, 2 }.
std::pair<unsigned, unsigned> GetVecRegPairIndices(unsigned VecRegPair);

// Attempt to find and replace compound pairs
void tryCompound(MCInstrInfo const &MCII, MCSubtargetInfo const &STI,
                 MCContext &Context, MCInst &MCI);

} // end namespace HexagonMCInstrInfo

} // end namespace llvm

#endif // LLVM_LIB_TARGET_HEXAGON_MCTARGETDESC_HEXAGONMCINSTRINFO_H