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llvm-project/llvm/lib/Target/X86/X86InstrInfo.h

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//===- X86InstrInfo.h - X86 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 X86 implementation of the TargetInstrInfo class.
//
//===----------------------------------------------------------------------===//
#ifndef X86INSTRUCTIONINFO_H
#define X86INSTRUCTIONINFO_H
#include "llvm/Target/TargetInstrInfo.h"
#include "X86.h"
#include "X86RegisterInfo.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/Target/TargetRegisterInfo.h"
namespace llvm {
class X86RegisterInfo;
class X86TargetMachine;
namespace X86 {
// X86 specific condition code. These correspond to X86_*_COND in
// X86InstrInfo.td. They must be kept in synch.
enum CondCode {
COND_A = 0,
COND_AE = 1,
COND_B = 2,
COND_BE = 3,
COND_E = 4,
COND_G = 5,
COND_GE = 6,
COND_L = 7,
COND_LE = 8,
COND_NE = 9,
COND_NO = 10,
COND_NP = 11,
COND_NS = 12,
COND_O = 13,
COND_P = 14,
COND_S = 15,
// Artificial condition codes. These are used by AnalyzeBranch
// to indicate a block terminated with two conditional branches to
// the same location. This occurs in code using FCMP_OEQ or FCMP_UNE,
// which can't be represented on x86 with a single condition. These
// are never used in MachineInstrs.
COND_NE_OR_P,
COND_NP_OR_E,
COND_INVALID
};
// Turn condition code into conditional branch opcode.
unsigned GetCondBranchFromCond(CondCode CC);
/// GetOppositeBranchCondition - Return the inverse of the specified cond,
/// e.g. turning COND_E to COND_NE.
CondCode GetOppositeBranchCondition(X86::CondCode CC);
}
/// X86II - This namespace holds all of the target specific flags that
/// instruction info tracks.
///
namespace X86II {
/// Target Operand Flag enum.
enum TOF {
//===------------------------------------------------------------------===//
// X86 Specific MachineOperand flags.
MO_NO_FLAG,
/// MO_GOT_ABSOLUTE_ADDRESS - On a symbol operand, this represents a
/// relocation of:
/// SYMBOL_LABEL + [. - PICBASELABEL]
MO_GOT_ABSOLUTE_ADDRESS,
/// MO_PIC_BASE_OFFSET - On a symbol operand this indicates that the
/// immediate should get the value of the symbol minus the PIC base label:
/// SYMBOL_LABEL - PICBASELABEL
MO_PIC_BASE_OFFSET,
/// MO_GOT - On a symbol operand this indicates that the immediate is the
/// offset to the GOT entry for the symbol name from the base of the GOT.
///
/// See the X86-64 ELF ABI supplement for more details.
/// SYMBOL_LABEL @GOT
MO_GOT,
/// MO_GOTOFF - On a symbol operand this indicates that the immediate is
/// the offset to the location of the symbol name from the base of the GOT.
///
/// See the X86-64 ELF ABI supplement for more details.
/// SYMBOL_LABEL @GOTOFF
MO_GOTOFF,
/// MO_GOTPCREL - On a symbol operand this indicates that the immediate is
/// offset to the GOT entry for the symbol name from the current code
/// location.
///
/// See the X86-64 ELF ABI supplement for more details.
/// SYMBOL_LABEL @GOTPCREL
MO_GOTPCREL,
/// MO_PLT - On a symbol operand this indicates that the immediate is
/// offset to the PLT entry of symbol name from the current code location.
///
/// See the X86-64 ELF ABI supplement for more details.
/// SYMBOL_LABEL @PLT
MO_PLT,
/// MO_TLSGD - On a symbol operand this indicates that the immediate is
/// some TLS offset.
///
/// See 'ELF Handling for Thread-Local Storage' for more details.
/// SYMBOL_LABEL @TLSGD
MO_TLSGD,
/// MO_GOTTPOFF - On a symbol operand this indicates that the immediate is
/// some TLS offset.
///
/// See 'ELF Handling for Thread-Local Storage' for more details.
/// SYMBOL_LABEL @GOTTPOFF
MO_GOTTPOFF,
/// MO_INDNTPOFF - On a symbol operand this indicates that the immediate is
/// some TLS offset.
///
/// See 'ELF Handling for Thread-Local Storage' for more details.
/// SYMBOL_LABEL @INDNTPOFF
MO_INDNTPOFF,
/// MO_TPOFF - On a symbol operand this indicates that the immediate is
/// some TLS offset.
///
/// See 'ELF Handling for Thread-Local Storage' for more details.
/// SYMBOL_LABEL @TPOFF
MO_TPOFF,
/// MO_NTPOFF - On a symbol operand this indicates that the immediate is
/// some TLS offset.
///
/// See 'ELF Handling for Thread-Local Storage' for more details.
/// SYMBOL_LABEL @NTPOFF
MO_NTPOFF,
/// MO_DLLIMPORT - On a symbol operand "FOO", this indicates that the
/// reference is actually to the "__imp_FOO" symbol. This is used for
/// dllimport linkage on windows.
MO_DLLIMPORT,
/// MO_DARWIN_STUB - On a symbol operand "FOO", this indicates that the
/// reference is actually to the "FOO$stub" symbol. This is used for calls
/// and jumps to external functions on Tiger and before.
MO_DARWIN_STUB,
/// MO_DARWIN_NONLAZY - On a symbol operand "FOO", this indicates that the
/// reference is actually to the "FOO$non_lazy_ptr" symbol, which is a
/// non-PIC-base-relative reference to a non-hidden dyld lazy pointer stub.
MO_DARWIN_NONLAZY,
/// MO_DARWIN_NONLAZY_PIC_BASE - On a symbol operand "FOO", this indicates
/// that the reference is actually to "FOO$non_lazy_ptr - PICBASE", which is
/// a PIC-base-relative reference to a non-hidden dyld lazy pointer stub.
MO_DARWIN_NONLAZY_PIC_BASE,
/// MO_DARWIN_HIDDEN_NONLAZY_PIC_BASE - On a symbol operand "FOO", this
/// indicates that the reference is actually to "FOO$non_lazy_ptr -PICBASE",
/// which is a PIC-base-relative reference to a hidden dyld lazy pointer
/// stub.
MO_DARWIN_HIDDEN_NONLAZY_PIC_BASE
};
}
/// isGlobalStubReference - Return true if the specified TargetFlag operand is
/// a reference to a stub for a global, not the global itself.
inline static bool isGlobalStubReference(unsigned char TargetFlag) {
switch (TargetFlag) {
case X86II::MO_DLLIMPORT: // dllimport stub.
case X86II::MO_GOTPCREL: // rip-relative GOT reference.
case X86II::MO_GOT: // normal GOT reference.
case X86II::MO_DARWIN_NONLAZY_PIC_BASE: // Normal $non_lazy_ptr ref.
case X86II::MO_DARWIN_NONLAZY: // Normal $non_lazy_ptr ref.
case X86II::MO_DARWIN_HIDDEN_NONLAZY_PIC_BASE: // Hidden $non_lazy_ptr ref.
return true;
default:
return false;
}
}
/// isGlobalRelativeToPICBase - Return true if the specified global value
/// reference is relative to a 32-bit PIC base (X86ISD::GlobalBaseReg). If this
/// is true, the addressing mode has the PIC base register added in (e.g. EBX).
inline static bool isGlobalRelativeToPICBase(unsigned char TargetFlag) {
switch (TargetFlag) {
case X86II::MO_GOTOFF: // isPICStyleGOT: local global.
case X86II::MO_GOT: // isPICStyleGOT: other global.
case X86II::MO_PIC_BASE_OFFSET: // Darwin local global.
case X86II::MO_DARWIN_NONLAZY_PIC_BASE: // Darwin/32 external global.
case X86II::MO_DARWIN_HIDDEN_NONLAZY_PIC_BASE: // Darwin/32 hidden global.
return true;
default:
return false;
}
}
/// X86II - This namespace holds all of the target specific flags that
/// instruction info tracks.
///
namespace X86II {
enum {
//===------------------------------------------------------------------===//
// Instruction encodings. These are the standard/most common forms for X86
// instructions.
//
// PseudoFrm - This represents an instruction that is a pseudo instruction
// or one that has not been implemented yet. It is illegal to code generate
// it, but tolerated for intermediate implementation stages.
Pseudo = 0,
/// Raw - This form is for instructions that don't have any operands, so
/// they are just a fixed opcode value, like 'leave'.
RawFrm = 1,
/// AddRegFrm - This form is used for instructions like 'push r32' that have
/// their one register operand added to their opcode.
AddRegFrm = 2,
/// MRMDestReg - This form is used for instructions that use the Mod/RM byte
/// to specify a destination, which in this case is a register.
///
MRMDestReg = 3,
/// MRMDestMem - This form is used for instructions that use the Mod/RM byte
/// to specify a destination, which in this case is memory.
///
MRMDestMem = 4,
/// MRMSrcReg - This form is used for instructions that use the Mod/RM byte
/// to specify a source, which in this case is a register.
///
MRMSrcReg = 5,
/// MRMSrcMem - This form is used for instructions that use the Mod/RM byte
/// to specify a source, which in this case is memory.
///
MRMSrcMem = 6,
/// MRM[0-7][rm] - These forms are used to represent instructions that use
/// a Mod/RM byte, and use the middle field to hold extended opcode
/// information. In the intel manual these are represented as /0, /1, ...
///
// First, instructions that operate on a register r/m operand...
MRM0r = 16, MRM1r = 17, MRM2r = 18, MRM3r = 19, // Format /0 /1 /2 /3
MRM4r = 20, MRM5r = 21, MRM6r = 22, MRM7r = 23, // Format /4 /5 /6 /7
// Next, instructions that operate on a memory r/m operand...
MRM0m = 24, MRM1m = 25, MRM2m = 26, MRM3m = 27, // Format /0 /1 /2 /3
MRM4m = 28, MRM5m = 29, MRM6m = 30, MRM7m = 31, // Format /4 /5 /6 /7
// MRMInitReg - This form is used for instructions whose source and
// destinations are the same register.
MRMInitReg = 32,
FormMask = 63,
//===------------------------------------------------------------------===//
// Actual flags...
// OpSize - Set if this instruction requires an operand size prefix (0x66),
// which most often indicates that the instruction operates on 16 bit data
// instead of 32 bit data.
OpSize = 1 << 6,
// AsSize - Set if this instruction requires an operand size prefix (0x67),
// which most often indicates that the instruction address 16 bit address
// instead of 32 bit address (or 32 bit address in 64 bit mode).
AdSize = 1 << 7,
//===------------------------------------------------------------------===//
// Op0Mask - There are several prefix bytes that are used to form two byte
// opcodes. These are currently 0x0F, 0xF3, and 0xD8-0xDF. This mask is
// used to obtain the setting of this field. If no bits in this field is
// set, there is no prefix byte for obtaining a multibyte opcode.
//
Op0Shift = 8,
Op0Mask = 0xF << Op0Shift,
// TB - TwoByte - Set if this instruction has a two byte opcode, which
// starts with a 0x0F byte before the real opcode.
TB = 1 << Op0Shift,
// REP - The 0xF3 prefix byte indicating repetition of the following
// instruction.
REP = 2 << Op0Shift,
// D8-DF - These escape opcodes are used by the floating point unit. These
// values must remain sequential.
D8 = 3 << Op0Shift, D9 = 4 << Op0Shift,
DA = 5 << Op0Shift, DB = 6 << Op0Shift,
DC = 7 << Op0Shift, DD = 8 << Op0Shift,
DE = 9 << Op0Shift, DF = 10 << Op0Shift,
// XS, XD - These prefix codes are for single and double precision scalar
// floating point operations performed in the SSE registers.
XD = 11 << Op0Shift, XS = 12 << Op0Shift,
// T8, TA - Prefix after the 0x0F prefix.
T8 = 13 << Op0Shift, TA = 14 << Op0Shift,
// TF - Prefix before and after 0x0F
TF = 15 << Op0Shift,
//===------------------------------------------------------------------===//
// REX_W - REX prefixes are instruction prefixes used in 64-bit mode.
// They are used to specify GPRs and SSE registers, 64-bit operand size,
// etc. We only cares about REX.W and REX.R bits and only the former is
// statically determined.
//
REXShift = 12,
REX_W = 1 << REXShift,
//===------------------------------------------------------------------===//
// This three-bit field describes the size of an immediate operand. Zero is
// unused so that we can tell if we forgot to set a value.
ImmShift = 13,
ImmMask = 7 << ImmShift,
Imm8 = 1 << ImmShift,
Imm16 = 2 << ImmShift,
Imm32 = 3 << ImmShift,
Imm64 = 4 << ImmShift,
//===------------------------------------------------------------------===//
// FP Instruction Classification... Zero is non-fp instruction.
// FPTypeMask - Mask for all of the FP types...
FPTypeShift = 16,
FPTypeMask = 7 << FPTypeShift,
// NotFP - The default, set for instructions that do not use FP registers.
NotFP = 0 << FPTypeShift,
// ZeroArgFP - 0 arg FP instruction which implicitly pushes ST(0), f.e. fld0
ZeroArgFP = 1 << FPTypeShift,
// OneArgFP - 1 arg FP instructions which implicitly read ST(0), such as fst
OneArgFP = 2 << FPTypeShift,
// OneArgFPRW - 1 arg FP instruction which implicitly read ST(0) and write a
// result back to ST(0). For example, fcos, fsqrt, etc.
//
OneArgFPRW = 3 << FPTypeShift,
// TwoArgFP - 2 arg FP instructions which implicitly read ST(0), and an
// explicit argument, storing the result to either ST(0) or the implicit
// argument. For example: fadd, fsub, fmul, etc...
TwoArgFP = 4 << FPTypeShift,
// CompareFP - 2 arg FP instructions which implicitly read ST(0) and an
// explicit argument, but have no destination. Example: fucom, fucomi, ...
CompareFP = 5 << FPTypeShift,
// CondMovFP - "2 operand" floating point conditional move instructions.
CondMovFP = 6 << FPTypeShift,
// SpecialFP - Special instruction forms. Dispatch by opcode explicitly.
SpecialFP = 7 << FPTypeShift,
// Lock prefix
LOCKShift = 19,
LOCK = 1 << LOCKShift,
// Segment override prefixes. Currently we just need ability to address
// stuff in gs and fs segments.
SegOvrShift = 20,
SegOvrMask = 3 << SegOvrShift,
FS = 1 << SegOvrShift,
GS = 2 << SegOvrShift,
// Bits 22 -> 23 are unused
OpcodeShift = 24,
OpcodeMask = 0xFF << OpcodeShift
};
}
const int X86AddrNumOperands = 5;
inline static bool isScale(const MachineOperand &MO) {
return MO.isImm() &&
(MO.getImm() == 1 || MO.getImm() == 2 ||
MO.getImm() == 4 || MO.getImm() == 8);
}
inline static bool isLeaMem(const MachineInstr *MI, unsigned Op) {
if (MI->getOperand(Op).isFI()) return true;
return Op+4 <= MI->getNumOperands() &&
MI->getOperand(Op ).isReg() && isScale(MI->getOperand(Op+1)) &&
MI->getOperand(Op+2).isReg() &&
(MI->getOperand(Op+3).isImm() ||
MI->getOperand(Op+3).isGlobal() ||
MI->getOperand(Op+3).isCPI() ||
MI->getOperand(Op+3).isJTI());
}
inline static bool isMem(const MachineInstr *MI, unsigned Op) {
if (MI->getOperand(Op).isFI()) return true;
return Op+5 <= MI->getNumOperands() &&
MI->getOperand(Op+4).isReg() &&
isLeaMem(MI, Op);
}
class X86InstrInfo : public TargetInstrInfoImpl {
X86TargetMachine &TM;
const X86RegisterInfo RI;
/// RegOp2MemOpTable2Addr, RegOp2MemOpTable0, RegOp2MemOpTable1,
/// RegOp2MemOpTable2 - Load / store folding opcode maps.
///
DenseMap<unsigned*, std::pair<unsigned,unsigned> > RegOp2MemOpTable2Addr;
DenseMap<unsigned*, std::pair<unsigned,unsigned> > RegOp2MemOpTable0;
DenseMap<unsigned*, std::pair<unsigned,unsigned> > RegOp2MemOpTable1;
DenseMap<unsigned*, std::pair<unsigned,unsigned> > RegOp2MemOpTable2;
/// MemOp2RegOpTable - Load / store unfolding opcode map.
///
DenseMap<unsigned*, std::pair<unsigned, unsigned> > MemOp2RegOpTable;
public:
explicit X86InstrInfo(X86TargetMachine &tm);
/// 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).
///
virtual const X86RegisterInfo &getRegisterInfo() const { return RI; }
/// Return true if the instruction is a register to register move and return
/// the source and dest operands and their sub-register indices by reference.
virtual bool isMoveInstr(const MachineInstr &MI,
unsigned &SrcReg, unsigned &DstReg,
unsigned &SrcSubIdx, unsigned &DstSubIdx) const;
unsigned isLoadFromStackSlot(const MachineInstr *MI, int &FrameIndex) const;
unsigned isStoreToStackSlot(const MachineInstr *MI, int &FrameIndex) const;
bool isReallyTriviallyReMaterializable(const MachineInstr *MI) const;
void reMaterialize(MachineBasicBlock &MBB, MachineBasicBlock::iterator MI,
unsigned DestReg, unsigned SubIdx,
const MachineInstr *Orig) const;
/// convertToThreeAddress - This method must be implemented by targets that
/// set the M_CONVERTIBLE_TO_3_ADDR flag. When this flag is set, the target
/// may be able to convert a two-address instruction into a true
/// three-address instruction on demand. This allows the X86 target (for
/// example) to convert ADD and SHL instructions into LEA instructions if they
/// would require register copies due to two-addressness.
///
/// This method returns a null pointer if the transformation cannot be
/// performed, otherwise it returns the new instruction.
///
virtual MachineInstr *convertToThreeAddress(MachineFunction::iterator &MFI,
MachineBasicBlock::iterator &MBBI,
LiveVariables *LV) const;
/// commuteInstruction - We have a few instructions that must be hacked on to
/// commute them.
///
virtual MachineInstr *commuteInstruction(MachineInstr *MI, bool NewMI) const;
// Branch analysis.
virtual bool isUnpredicatedTerminator(const MachineInstr* MI) const;
virtual bool AnalyzeBranch(MachineBasicBlock &MBB, MachineBasicBlock *&TBB,
MachineBasicBlock *&FBB,
SmallVectorImpl<MachineOperand> &Cond,
bool AllowModify) const;
virtual unsigned RemoveBranch(MachineBasicBlock &MBB) const;
virtual unsigned InsertBranch(MachineBasicBlock &MBB, MachineBasicBlock *TBB,
MachineBasicBlock *FBB,
const SmallVectorImpl<MachineOperand> &Cond) const;
virtual bool copyRegToReg(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI,
unsigned DestReg, unsigned SrcReg,
const TargetRegisterClass *DestRC,
const TargetRegisterClass *SrcRC) const;
virtual void storeRegToStackSlot(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI,
unsigned SrcReg, bool isKill, int FrameIndex,
const TargetRegisterClass *RC) const;
virtual void storeRegToAddr(MachineFunction &MF, unsigned SrcReg, bool isKill,
SmallVectorImpl<MachineOperand> &Addr,
const TargetRegisterClass *RC,
SmallVectorImpl<MachineInstr*> &NewMIs) const;
virtual void loadRegFromStackSlot(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI,
unsigned DestReg, int FrameIndex,
const TargetRegisterClass *RC) const;
virtual void loadRegFromAddr(MachineFunction &MF, unsigned DestReg,
SmallVectorImpl<MachineOperand> &Addr,
const TargetRegisterClass *RC,
SmallVectorImpl<MachineInstr*> &NewMIs) const;
virtual bool spillCalleeSavedRegisters(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI,
const std::vector<CalleeSavedInfo> &CSI) const;
virtual bool restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI,
const std::vector<CalleeSavedInfo> &CSI) const;
/// foldMemoryOperand - If this target supports it, fold a load or store of
/// the specified stack slot into the specified machine instruction for the
/// specified operand(s). If this is possible, the target should perform the
/// folding and return true, otherwise it should return false. If it folds
/// the instruction, it is likely that the MachineInstruction the iterator
/// references has been changed.
virtual MachineInstr* foldMemoryOperandImpl(MachineFunction &MF,
MachineInstr* MI,
const SmallVectorImpl<unsigned> &Ops,
int FrameIndex) const;
/// foldMemoryOperand - Same as the previous version except it allows folding
/// of any load and store from / to any address, not just from a specific
/// stack slot.
virtual MachineInstr* foldMemoryOperandImpl(MachineFunction &MF,
MachineInstr* MI,
const SmallVectorImpl<unsigned> &Ops,
MachineInstr* LoadMI) const;
/// canFoldMemoryOperand - Returns true if the specified load / store is
/// folding is possible.
virtual bool canFoldMemoryOperand(const MachineInstr*,
const SmallVectorImpl<unsigned> &) const;
/// unfoldMemoryOperand - Separate a single instruction which folded a load or
/// a store or a load and a store into two or more instruction. If this is
/// possible, returns true as well as the new instructions by reference.
virtual bool unfoldMemoryOperand(MachineFunction &MF, MachineInstr *MI,
unsigned Reg, bool UnfoldLoad, bool UnfoldStore,
SmallVectorImpl<MachineInstr*> &NewMIs) const;
virtual bool unfoldMemoryOperand(SelectionDAG &DAG, SDNode *N,
SmallVectorImpl<SDNode*> &NewNodes) const;
/// getOpcodeAfterMemoryUnfold - Returns the opcode of the would be new
/// instruction after load / store are unfolded from an instruction of the
/// specified opcode. It returns zero if the specified unfolding is not
/// possible.
virtual unsigned getOpcodeAfterMemoryUnfold(unsigned Opc,
bool UnfoldLoad, bool UnfoldStore) const;
virtual bool BlockHasNoFallThrough(const MachineBasicBlock &MBB) const;
virtual
bool ReverseBranchCondition(SmallVectorImpl<MachineOperand> &Cond) const;
/// isSafeToMoveRegClassDefs - Return true if it's safe to move a machine
/// instruction that defines the specified register class.
bool isSafeToMoveRegClassDefs(const TargetRegisterClass *RC) const;
// getBaseOpcodeFor - This function returns the "base" X86 opcode for the
// specified machine instruction.
//
unsigned char getBaseOpcodeFor(const TargetInstrDesc *TID) const {
return TID->TSFlags >> X86II::OpcodeShift;
}
unsigned char getBaseOpcodeFor(unsigned Opcode) const {
return getBaseOpcodeFor(&get(Opcode));
}
static bool isX86_64NonExtLowByteReg(unsigned reg) {
return (reg == X86::SPL || reg == X86::BPL ||
reg == X86::SIL || reg == X86::DIL);
}
static unsigned sizeOfImm(const TargetInstrDesc *Desc);
static bool isX86_64ExtendedReg(const MachineOperand &MO);
static unsigned determineREX(const MachineInstr &MI);
/// GetInstSize - Returns the size of the specified MachineInstr.
///
virtual unsigned GetInstSizeInBytes(const MachineInstr *MI) const;
/// getGlobalBaseReg - Return a virtual register initialized with the
/// the global base register value. Output instructions required to
/// initialize the register in the function entry block, if necessary.
///
unsigned getGlobalBaseReg(MachineFunction *MF) const;
private:
MachineInstr* foldMemoryOperandImpl(MachineFunction &MF,
MachineInstr* MI,
unsigned OpNum,
const SmallVectorImpl<MachineOperand> &MOs,
unsigned Size, unsigned Alignment) const;
};
} // End llvm namespace
#endif
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