MachineOperand.h revision 938200859ec714f59f8f93acceb999e212e9c539
1//===-- llvm/CodeGen/MachineOperand.h - MachineOperand class ----*- C++ -*-===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file contains the declaration of the MachineOperand class.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef LLVM_CODEGEN_MACHINEOPERAND_H
15#define LLVM_CODEGEN_MACHINEOPERAND_H
16
17#include "llvm/Support/DataTypes.h"
18#include <cassert>
19
20namespace llvm {
21
22class BlockAddress;
23class ConstantFP;
24class ConstantInt;
25class GlobalValue;
26class MachineBasicBlock;
27class MachineInstr;
28class MachineRegisterInfo;
29class MDNode;
30class TargetMachine;
31class TargetRegisterInfo;
32class raw_ostream;
33class MCSymbol;
34
35/// MachineOperand class - Representation of each machine instruction operand.
36///
37class MachineOperand {
38public:
39  enum MachineOperandType {
40    MO_Register,               ///< Register operand.
41    MO_Immediate,              ///< Immediate operand
42    MO_CImmediate,             ///< Immediate >64bit operand
43    MO_FPImmediate,            ///< Floating-point immediate operand
44    MO_MachineBasicBlock,      ///< MachineBasicBlock reference
45    MO_FrameIndex,             ///< Abstract Stack Frame Index
46    MO_ConstantPoolIndex,      ///< Address of indexed Constant in Constant Pool
47    MO_JumpTableIndex,         ///< Address of indexed Jump Table for switch
48    MO_ExternalSymbol,         ///< Name of external global symbol
49    MO_GlobalAddress,          ///< Address of a global value
50    MO_BlockAddress,           ///< Address of a basic block
51    MO_RegisterMask,           ///< Mask of preserved registers.
52    MO_Metadata,               ///< Metadata reference (for debug info)
53    MO_MCSymbol                ///< MCSymbol reference (for debug/eh info)
54  };
55
56private:
57  /// OpKind - Specify what kind of operand this is.  This discriminates the
58  /// union.
59  unsigned char OpKind; // MachineOperandType
60
61  /// SubReg - Subregister number, only valid for MO_Register.  A value of 0
62  /// indicates the MO_Register has no subReg.
63  unsigned char SubReg;
64
65  /// TargetFlags - This is a set of target-specific operand flags.
66  unsigned char TargetFlags;
67
68  /// IsDef/IsImp/IsKill/IsDead flags - These are only valid for MO_Register
69  /// operands.
70
71  /// IsDef - True if this is a def, false if this is a use of the register.
72  ///
73  bool IsDef : 1;
74
75  /// IsImp - True if this is an implicit def or use, false if it is explicit.
76  ///
77  bool IsImp : 1;
78
79  /// IsKill - True if this instruction is the last use of the register on this
80  /// path through the function.  This is only valid on uses of registers.
81  bool IsKill : 1;
82
83  /// IsDead - True if this register is never used by a subsequent instruction.
84  /// This is only valid on definitions of registers.
85  bool IsDead : 1;
86
87  /// IsUndef - True if this register operand reads an "undef" value, i.e. the
88  /// read value doesn't matter.  This flag can be set on both use and def
89  /// operands.  On a sub-register def operand, it refers to the part of the
90  /// register that isn't written.  On a full-register def operand, it is a
91  /// noop.  See readsReg().
92  ///
93  /// This is only valid on registers.
94  ///
95  /// Note that an instruction may have multiple <undef> operands referring to
96  /// the same register.  In that case, the instruction may depend on those
97  /// operands reading the same dont-care value.  For example:
98  ///
99  ///   %vreg1<def> = XOR %vreg2<undef>, %vreg2<undef>
100  ///
101  /// Any register can be used for %vreg2, and its value doesn't matter, but
102  /// the two operands must be the same register.
103  ///
104  bool IsUndef : 1;
105
106  /// IsInternalRead - True if this operand reads a value that was defined
107  /// inside the same instruction or bundle.  This flag can be set on both use
108  /// and def operands.  On a sub-register def operand, it refers to the part
109  /// of the register that isn't written.  On a full-register def operand, it
110  /// is a noop.
111  ///
112  /// When this flag is set, the instruction bundle must contain at least one
113  /// other def of the register.  If multiple instructions in the bundle define
114  /// the register, the meaning is target-defined.
115  bool IsInternalRead : 1;
116
117  /// IsEarlyClobber - True if this MO_Register 'def' operand is written to
118  /// by the MachineInstr before all input registers are read.  This is used to
119  /// model the GCC inline asm '&' constraint modifier.
120  bool IsEarlyClobber : 1;
121
122  /// IsDebug - True if this MO_Register 'use' operand is in a debug pseudo,
123  /// not a real instruction.  Such uses should be ignored during codegen.
124  bool IsDebug : 1;
125
126  /// SmallContents - This really should be part of the Contents union, but
127  /// lives out here so we can get a better packed struct.
128  /// MO_Register: Register number.
129  /// OffsetedInfo: Low bits of offset.
130  union {
131    unsigned RegNo;           // For MO_Register.
132    unsigned OffsetLo;        // Matches Contents.OffsetedInfo.OffsetHi.
133  } SmallContents;
134
135  /// ParentMI - This is the instruction that this operand is embedded into.
136  /// This is valid for all operand types, when the operand is in an instr.
137  MachineInstr *ParentMI;
138
139  /// Contents union - This contains the payload for the various operand types.
140  union {
141    MachineBasicBlock *MBB;   // For MO_MachineBasicBlock.
142    const ConstantFP *CFP;    // For MO_FPImmediate.
143    const ConstantInt *CI;    // For MO_CImmediate. Integers > 64bit.
144    int64_t ImmVal;           // For MO_Immediate.
145    const uint32_t *RegMask;  // For MO_RegisterMask.
146    const MDNode *MD;         // For MO_Metadata.
147    MCSymbol *Sym;            // For MO_MCSymbol
148
149    struct {                  // For MO_Register.
150      // Register number is in SmallContents.RegNo.
151      MachineOperand **Prev;  // Access list for register.
152      MachineOperand *Next;
153    } Reg;
154
155    /// OffsetedInfo - This struct contains the offset and an object identifier.
156    /// this represent the object as with an optional offset from it.
157    struct {
158      union {
159        int Index;                // For MO_*Index - The index itself.
160        const char *SymbolName;   // For MO_ExternalSymbol.
161        const GlobalValue *GV;    // For MO_GlobalAddress.
162        const BlockAddress *BA;   // For MO_BlockAddress.
163      } Val;
164      // Low bits of offset are in SmallContents.OffsetLo.
165      int OffsetHi;               // An offset from the object, high 32 bits.
166    } OffsetedInfo;
167  } Contents;
168
169  explicit MachineOperand(MachineOperandType K) : OpKind(K), ParentMI(0) {
170    TargetFlags = 0;
171  }
172public:
173  /// getType - Returns the MachineOperandType for this operand.
174  ///
175  MachineOperandType getType() const { return (MachineOperandType)OpKind; }
176
177  unsigned char getTargetFlags() const { return TargetFlags; }
178  void setTargetFlags(unsigned char F) { TargetFlags = F; }
179  void addTargetFlag(unsigned char F) { TargetFlags |= F; }
180
181
182  /// getParent - Return the instruction that this operand belongs to.
183  ///
184  MachineInstr *getParent() { return ParentMI; }
185  const MachineInstr *getParent() const { return ParentMI; }
186
187  /// clearParent - Reset the parent pointer.
188  ///
189  /// The MachineOperand copy constructor also copies ParentMI, expecting the
190  /// original to be deleted. If a MachineOperand is ever stored outside a
191  /// MachineInstr, the parent pointer must be cleared.
192  ///
193  /// Never call clearParent() on an operand in a MachineInstr.
194  ///
195  void clearParent() { ParentMI = 0; }
196
197  void print(raw_ostream &os, const TargetMachine *TM = 0) const;
198
199  //===--------------------------------------------------------------------===//
200  // Accessors that tell you what kind of MachineOperand you're looking at.
201  //===--------------------------------------------------------------------===//
202
203  /// isReg - Tests if this is a MO_Register operand.
204  bool isReg() const { return OpKind == MO_Register; }
205  /// isImm - Tests if this is a MO_Immediate operand.
206  bool isImm() const { return OpKind == MO_Immediate; }
207  /// isCImm - Test if t his is a MO_CImmediate operand.
208  bool isCImm() const { return OpKind == MO_CImmediate; }
209  /// isFPImm - Tests if this is a MO_FPImmediate operand.
210  bool isFPImm() const { return OpKind == MO_FPImmediate; }
211  /// isMBB - Tests if this is a MO_MachineBasicBlock operand.
212  bool isMBB() const { return OpKind == MO_MachineBasicBlock; }
213  /// isFI - Tests if this is a MO_FrameIndex operand.
214  bool isFI() const { return OpKind == MO_FrameIndex; }
215  /// isCPI - Tests if this is a MO_ConstantPoolIndex operand.
216  bool isCPI() const { return OpKind == MO_ConstantPoolIndex; }
217  /// isJTI - Tests if this is a MO_JumpTableIndex operand.
218  bool isJTI() const { return OpKind == MO_JumpTableIndex; }
219  /// isGlobal - Tests if this is a MO_GlobalAddress operand.
220  bool isGlobal() const { return OpKind == MO_GlobalAddress; }
221  /// isSymbol - Tests if this is a MO_ExternalSymbol operand.
222  bool isSymbol() const { return OpKind == MO_ExternalSymbol; }
223  /// isBlockAddress - Tests if this is a MO_BlockAddress operand.
224  bool isBlockAddress() const { return OpKind == MO_BlockAddress; }
225  /// isRegMask - Tests if this is a MO_RegisterMask operand.
226  bool isRegMask() const { return OpKind == MO_RegisterMask; }
227  /// isMetadata - Tests if this is a MO_Metadata operand.
228  bool isMetadata() const { return OpKind == MO_Metadata; }
229  bool isMCSymbol() const { return OpKind == MO_MCSymbol; }
230
231
232  //===--------------------------------------------------------------------===//
233  // Accessors for Register Operands
234  //===--------------------------------------------------------------------===//
235
236  /// getReg - Returns the register number.
237  unsigned getReg() const {
238    assert(isReg() && "This is not a register operand!");
239    return SmallContents.RegNo;
240  }
241
242  unsigned getSubReg() const {
243    assert(isReg() && "Wrong MachineOperand accessor");
244    return (unsigned)SubReg;
245  }
246
247  bool isUse() const {
248    assert(isReg() && "Wrong MachineOperand accessor");
249    return !IsDef;
250  }
251
252  bool isDef() const {
253    assert(isReg() && "Wrong MachineOperand accessor");
254    return IsDef;
255  }
256
257  bool isImplicit() const {
258    assert(isReg() && "Wrong MachineOperand accessor");
259    return IsImp;
260  }
261
262  bool isDead() const {
263    assert(isReg() && "Wrong MachineOperand accessor");
264    return IsDead;
265  }
266
267  bool isKill() const {
268    assert(isReg() && "Wrong MachineOperand accessor");
269    return IsKill;
270  }
271
272  bool isUndef() const {
273    assert(isReg() && "Wrong MachineOperand accessor");
274    return IsUndef;
275  }
276
277  bool isInternalRead() const {
278    assert(isReg() && "Wrong MachineOperand accessor");
279    return IsInternalRead;
280  }
281
282  bool isEarlyClobber() const {
283    assert(isReg() && "Wrong MachineOperand accessor");
284    return IsEarlyClobber;
285  }
286
287  bool isDebug() const {
288    assert(isReg() && "Wrong MachineOperand accessor");
289    return IsDebug;
290  }
291
292  /// readsReg - Returns true if this operand reads the previous value of its
293  /// register.  A use operand with the <undef> flag set doesn't read its
294  /// register.  A sub-register def implicitly reads the other parts of the
295  /// register being redefined unless the <undef> flag is set.
296  ///
297  /// This refers to reading the register value from before the current
298  /// instruction or bundle. Internal bundle reads are not included.
299  bool readsReg() const {
300    assert(isReg() && "Wrong MachineOperand accessor");
301    return !isUndef() && !isInternalRead() && (isUse() || getSubReg());
302  }
303
304  /// getNextOperandForReg - Return the next MachineOperand in the function that
305  /// uses or defines this register.
306  MachineOperand *getNextOperandForReg() const {
307    assert(isReg() && "This is not a register operand!");
308    return Contents.Reg.Next;
309  }
310
311  //===--------------------------------------------------------------------===//
312  // Mutators for Register Operands
313  //===--------------------------------------------------------------------===//
314
315  /// Change the register this operand corresponds to.
316  ///
317  void setReg(unsigned Reg);
318
319  void setSubReg(unsigned subReg) {
320    assert(isReg() && "Wrong MachineOperand accessor");
321    SubReg = (unsigned char)subReg;
322  }
323
324  /// substVirtReg - Substitute the current register with the virtual
325  /// subregister Reg:SubReg. Take any existing SubReg index into account,
326  /// using TargetRegisterInfo to compose the subreg indices if necessary.
327  /// Reg must be a virtual register, SubIdx can be 0.
328  ///
329  void substVirtReg(unsigned Reg, unsigned SubIdx, const TargetRegisterInfo&);
330
331  /// substPhysReg - Substitute the current register with the physical register
332  /// Reg, taking any existing SubReg into account. For instance,
333  /// substPhysReg(%EAX) will change %reg1024:sub_8bit to %AL.
334  ///
335  void substPhysReg(unsigned Reg, const TargetRegisterInfo&);
336
337  void setIsUse(bool Val = true) {
338    assert(isReg() && "Wrong MachineOperand accessor");
339    assert((Val || !isDebug()) && "Marking a debug operation as def");
340    IsDef = !Val;
341  }
342
343  void setIsDef(bool Val = true) {
344    assert(isReg() && "Wrong MachineOperand accessor");
345    assert((!Val || !isDebug()) && "Marking a debug operation as def");
346    IsDef = Val;
347  }
348
349  void setImplicit(bool Val = true) {
350    assert(isReg() && "Wrong MachineOperand accessor");
351    IsImp = Val;
352  }
353
354  void setIsKill(bool Val = true) {
355    assert(isReg() && !IsDef && "Wrong MachineOperand accessor");
356    assert((!Val || !isDebug()) && "Marking a debug operation as kill");
357    IsKill = Val;
358  }
359
360  void setIsDead(bool Val = true) {
361    assert(isReg() && IsDef && "Wrong MachineOperand accessor");
362    IsDead = Val;
363  }
364
365  void setIsUndef(bool Val = true) {
366    assert(isReg() && "Wrong MachineOperand accessor");
367    IsUndef = Val;
368  }
369
370  void setIsInternalRead(bool Val = true) {
371    assert(isReg() && "Wrong MachineOperand accessor");
372    IsInternalRead = Val;
373  }
374
375  void setIsEarlyClobber(bool Val = true) {
376    assert(isReg() && IsDef && "Wrong MachineOperand accessor");
377    IsEarlyClobber = Val;
378  }
379
380  void setIsDebug(bool Val = true) {
381    assert(isReg() && IsDef && "Wrong MachineOperand accessor");
382    IsDebug = Val;
383  }
384
385  //===--------------------------------------------------------------------===//
386  // Accessors for various operand types.
387  //===--------------------------------------------------------------------===//
388
389  int64_t getImm() const {
390    assert(isImm() && "Wrong MachineOperand accessor");
391    return Contents.ImmVal;
392  }
393
394  const ConstantInt *getCImm() const {
395    assert(isCImm() && "Wrong MachineOperand accessor");
396    return Contents.CI;
397  }
398
399  const ConstantFP *getFPImm() const {
400    assert(isFPImm() && "Wrong MachineOperand accessor");
401    return Contents.CFP;
402  }
403
404  MachineBasicBlock *getMBB() const {
405    assert(isMBB() && "Wrong MachineOperand accessor");
406    return Contents.MBB;
407  }
408
409  int getIndex() const {
410    assert((isFI() || isCPI() || isJTI()) &&
411           "Wrong MachineOperand accessor");
412    return Contents.OffsetedInfo.Val.Index;
413  }
414
415  const GlobalValue *getGlobal() const {
416    assert(isGlobal() && "Wrong MachineOperand accessor");
417    return Contents.OffsetedInfo.Val.GV;
418  }
419
420  const BlockAddress *getBlockAddress() const {
421    assert(isBlockAddress() && "Wrong MachineOperand accessor");
422    return Contents.OffsetedInfo.Val.BA;
423  }
424
425  MCSymbol *getMCSymbol() const {
426    assert(isMCSymbol() && "Wrong MachineOperand accessor");
427    return Contents.Sym;
428  }
429
430  /// getOffset - Return the offset from the symbol in this operand. This always
431  /// returns 0 for ExternalSymbol operands.
432  int64_t getOffset() const {
433    assert((isGlobal() || isSymbol() || isCPI() || isBlockAddress()) &&
434           "Wrong MachineOperand accessor");
435    return (int64_t(Contents.OffsetedInfo.OffsetHi) << 32) |
436           SmallContents.OffsetLo;
437  }
438
439  const char *getSymbolName() const {
440    assert(isSymbol() && "Wrong MachineOperand accessor");
441    return Contents.OffsetedInfo.Val.SymbolName;
442  }
443
444  /// clobbersPhysReg - Returns true if this RegMask clobbers PhysReg.
445  /// It is sometimes necessary to detach the register mask pointer from its
446  /// machine operand. This static method can be used for such detached bit
447  /// mask pointers.  clobbersPhysReg - Returns true if this RegMask operand
448  /// clobbers PhysReg.
449  static bool clobbersPhysReg(const uint32_t *RegMask, unsigned PhysReg) {
450    // See TargetRegisterInfo.h.
451    assert(PhysReg < (1u << 30) && "Not a physical register");
452    return !(RegMask[PhysReg / 32] & (1u << PhysReg % 32));
453  }
454
455  /// clobbersPhysReg - Returns true if this RegMask operand clobbers PhysReg.
456  bool clobbersPhysReg(unsigned PhysReg) const {
457     return clobbersPhysReg(getRegMask(), PhysReg);
458  }
459
460  /// getRegMask - Returns a bit mask of registers preserved by this RegMask
461  /// operand.
462  const uint32_t *getRegMask() const {
463    assert(isRegMask() && "Wrong MachineOperand accessor");
464    return Contents.RegMask;
465  }
466
467  const MDNode *getMetadata() const {
468    assert(isMetadata() && "Wrong MachineOperand accessor");
469    return Contents.MD;
470  }
471
472  //===--------------------------------------------------------------------===//
473  // Mutators for various operand types.
474  //===--------------------------------------------------------------------===//
475
476  void setImm(int64_t immVal) {
477    assert(isImm() && "Wrong MachineOperand mutator");
478    Contents.ImmVal = immVal;
479  }
480
481  void setOffset(int64_t Offset) {
482    assert((isGlobal() || isSymbol() || isCPI() || isBlockAddress()) &&
483        "Wrong MachineOperand accessor");
484    SmallContents.OffsetLo = unsigned(Offset);
485    Contents.OffsetedInfo.OffsetHi = int(Offset >> 32);
486  }
487
488  void setIndex(int Idx) {
489    assert((isFI() || isCPI() || isJTI()) &&
490           "Wrong MachineOperand accessor");
491    Contents.OffsetedInfo.Val.Index = Idx;
492  }
493
494  void setMBB(MachineBasicBlock *MBB) {
495    assert(isMBB() && "Wrong MachineOperand accessor");
496    Contents.MBB = MBB;
497  }
498
499  //===--------------------------------------------------------------------===//
500  // Other methods.
501  //===--------------------------------------------------------------------===//
502
503  /// isIdenticalTo - Return true if this operand is identical to the specified
504  /// operand. Note: This method ignores isKill and isDead properties.
505  bool isIdenticalTo(const MachineOperand &Other) const;
506
507  /// ChangeToImmediate - Replace this operand with a new immediate operand of
508  /// the specified value.  If an operand is known to be an immediate already,
509  /// the setImm method should be used.
510  void ChangeToImmediate(int64_t ImmVal);
511
512  /// ChangeToRegister - Replace this operand with a new register operand of
513  /// the specified value.  If an operand is known to be an register already,
514  /// the setReg method should be used.
515  void ChangeToRegister(unsigned Reg, bool isDef, bool isImp = false,
516                        bool isKill = false, bool isDead = false,
517                        bool isUndef = false, bool isDebug = false);
518
519  //===--------------------------------------------------------------------===//
520  // Construction methods.
521  //===--------------------------------------------------------------------===//
522
523  static MachineOperand CreateImm(int64_t Val) {
524    MachineOperand Op(MachineOperand::MO_Immediate);
525    Op.setImm(Val);
526    return Op;
527  }
528
529  static MachineOperand CreateCImm(const ConstantInt *CI) {
530    MachineOperand Op(MachineOperand::MO_CImmediate);
531    Op.Contents.CI = CI;
532    return Op;
533  }
534
535  static MachineOperand CreateFPImm(const ConstantFP *CFP) {
536    MachineOperand Op(MachineOperand::MO_FPImmediate);
537    Op.Contents.CFP = CFP;
538    return Op;
539  }
540
541  static MachineOperand CreateReg(unsigned Reg, bool isDef, bool isImp = false,
542                                  bool isKill = false, bool isDead = false,
543                                  bool isUndef = false,
544                                  bool isEarlyClobber = false,
545                                  unsigned SubReg = 0,
546                                  bool isDebug = false) {
547    MachineOperand Op(MachineOperand::MO_Register);
548    Op.IsDef = isDef;
549    Op.IsImp = isImp;
550    Op.IsKill = isKill;
551    Op.IsDead = isDead;
552    Op.IsUndef = isUndef;
553    Op.IsInternalRead = false;
554    Op.IsEarlyClobber = isEarlyClobber;
555    Op.IsDebug = isDebug;
556    Op.SmallContents.RegNo = Reg;
557    Op.Contents.Reg.Prev = 0;
558    Op.Contents.Reg.Next = 0;
559    Op.SubReg = SubReg;
560    return Op;
561  }
562  static MachineOperand CreateMBB(MachineBasicBlock *MBB,
563                                  unsigned char TargetFlags = 0) {
564    MachineOperand Op(MachineOperand::MO_MachineBasicBlock);
565    Op.setMBB(MBB);
566    Op.setTargetFlags(TargetFlags);
567    return Op;
568  }
569  static MachineOperand CreateFI(int Idx) {
570    MachineOperand Op(MachineOperand::MO_FrameIndex);
571    Op.setIndex(Idx);
572    return Op;
573  }
574  static MachineOperand CreateCPI(unsigned Idx, int Offset,
575                                  unsigned char TargetFlags = 0) {
576    MachineOperand Op(MachineOperand::MO_ConstantPoolIndex);
577    Op.setIndex(Idx);
578    Op.setOffset(Offset);
579    Op.setTargetFlags(TargetFlags);
580    return Op;
581  }
582  static MachineOperand CreateJTI(unsigned Idx,
583                                  unsigned char TargetFlags = 0) {
584    MachineOperand Op(MachineOperand::MO_JumpTableIndex);
585    Op.setIndex(Idx);
586    Op.setTargetFlags(TargetFlags);
587    return Op;
588  }
589  static MachineOperand CreateGA(const GlobalValue *GV, int64_t Offset,
590                                 unsigned char TargetFlags = 0) {
591    MachineOperand Op(MachineOperand::MO_GlobalAddress);
592    Op.Contents.OffsetedInfo.Val.GV = GV;
593    Op.setOffset(Offset);
594    Op.setTargetFlags(TargetFlags);
595    return Op;
596  }
597  static MachineOperand CreateES(const char *SymName,
598                                 unsigned char TargetFlags = 0) {
599    MachineOperand Op(MachineOperand::MO_ExternalSymbol);
600    Op.Contents.OffsetedInfo.Val.SymbolName = SymName;
601    Op.setOffset(0); // Offset is always 0.
602    Op.setTargetFlags(TargetFlags);
603    return Op;
604  }
605  static MachineOperand CreateBA(const BlockAddress *BA,
606                                 unsigned char TargetFlags = 0) {
607    MachineOperand Op(MachineOperand::MO_BlockAddress);
608    Op.Contents.OffsetedInfo.Val.BA = BA;
609    Op.setOffset(0); // Offset is always 0.
610    Op.setTargetFlags(TargetFlags);
611    return Op;
612  }
613  /// CreateRegMask - Creates a register mask operand referencing Mask.  The
614  /// operand does not take ownership of the memory referenced by Mask, it must
615  /// remain valid for the lifetime of the operand.
616  ///
617  /// A RegMask operand represents a set of non-clobbered physical registers on
618  /// an instruction that clobbers many registers, typically a call.  The bit
619  /// mask has a bit set for each physreg that is preserved by this
620  /// instruction, as described in the documentation for
621  /// TargetRegisterInfo::getCallPreservedMask().
622  ///
623  /// Any physreg with a 0 bit in the mask is clobbered by the instruction.
624  ///
625  static MachineOperand CreateRegMask(const uint32_t *Mask) {
626    assert(Mask && "Missing register mask");
627    MachineOperand Op(MachineOperand::MO_RegisterMask);
628    Op.Contents.RegMask = Mask;
629    return Op;
630  }
631  static MachineOperand CreateMetadata(const MDNode *Meta) {
632    MachineOperand Op(MachineOperand::MO_Metadata);
633    Op.Contents.MD = Meta;
634    return Op;
635  }
636
637  static MachineOperand CreateMCSymbol(MCSymbol *Sym) {
638    MachineOperand Op(MachineOperand::MO_MCSymbol);
639    Op.Contents.Sym = Sym;
640    return Op;
641  }
642
643  friend class MachineInstr;
644  friend class MachineRegisterInfo;
645private:
646  //===--------------------------------------------------------------------===//
647  // Methods for handling register use/def lists.
648  //===--------------------------------------------------------------------===//
649
650  /// isOnRegUseList - Return true if this operand is on a register use/def list
651  /// or false if not.  This can only be called for register operands that are
652  /// part of a machine instruction.
653  bool isOnRegUseList() const {
654    assert(isReg() && "Can only add reg operand to use lists");
655    return Contents.Reg.Prev != 0;
656  }
657
658  /// AddRegOperandToRegInfo - Add this register operand to the specified
659  /// MachineRegisterInfo.  If it is null, then the next/prev fields should be
660  /// explicitly nulled out.
661  void AddRegOperandToRegInfo(MachineRegisterInfo *RegInfo);
662
663  /// RemoveRegOperandFromRegInfo - Remove this register operand from the
664  /// MachineRegisterInfo it is linked with.
665  void RemoveRegOperandFromRegInfo();
666};
667
668inline raw_ostream &operator<<(raw_ostream &OS, const MachineOperand& MO) {
669  MO.print(OS, 0);
670  return OS;
671}
672
673} // End llvm namespace
674
675#endif
676