LLVM  6.0.0svn
InstrEmitter.cpp
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1 //==--- InstrEmitter.cpp - Emit MachineInstrs for the SelectionDAG class ---==//
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 implements the Emit routines for the SelectionDAG class, which creates
11 // MachineInstrs based on the decisions of the SelectionDAG instruction
12 // selection.
13 //
14 //===----------------------------------------------------------------------===//
15 
16 #include "InstrEmitter.h"
17 #include "SDNodeDbgValue.h"
18 #include "llvm/ADT/Statistic.h"
23 #include "llvm/CodeGen/StackMaps.h"
24 #include "llvm/IR/DataLayout.h"
25 #include "llvm/IR/DebugInfo.h"
26 #include "llvm/Support/Debug.h"
32 using namespace llvm;
33 
34 #define DEBUG_TYPE "instr-emitter"
35 
36 /// MinRCSize - Smallest register class we allow when constraining virtual
37 /// registers. If satisfying all register class constraints would require
38 /// using a smaller register class, emit a COPY to a new virtual register
39 /// instead.
40 const unsigned MinRCSize = 4;
41 
42 /// CountResults - The results of target nodes have register or immediate
43 /// operands first, then an optional chain, and optional glue operands (which do
44 /// not go into the resulting MachineInstr).
46  unsigned N = Node->getNumValues();
47  while (N && Node->getValueType(N - 1) == MVT::Glue)
48  --N;
49  if (N && Node->getValueType(N - 1) == MVT::Other)
50  --N; // Skip over chain result.
51  return N;
52 }
53 
54 /// countOperands - The inputs to target nodes have any actual inputs first,
55 /// followed by an optional chain operand, then an optional glue operand.
56 /// Compute the number of actual operands that will go into the resulting
57 /// MachineInstr.
58 ///
59 /// Also count physreg RegisterSDNode and RegisterMaskSDNode operands preceding
60 /// the chain and glue. These operands may be implicit on the machine instr.
61 static unsigned countOperands(SDNode *Node, unsigned NumExpUses,
62  unsigned &NumImpUses) {
63  unsigned N = Node->getNumOperands();
64  while (N && Node->getOperand(N - 1).getValueType() == MVT::Glue)
65  --N;
66  if (N && Node->getOperand(N - 1).getValueType() == MVT::Other)
67  --N; // Ignore chain if it exists.
68 
69  // Count RegisterSDNode and RegisterMaskSDNode operands for NumImpUses.
70  NumImpUses = N - NumExpUses;
71  for (unsigned I = N; I > NumExpUses; --I) {
72  if (isa<RegisterMaskSDNode>(Node->getOperand(I - 1)))
73  continue;
74  if (RegisterSDNode *RN = dyn_cast<RegisterSDNode>(Node->getOperand(I - 1)))
76  continue;
77  NumImpUses = N - I;
78  break;
79  }
80 
81  return N;
82 }
83 
84 /// EmitCopyFromReg - Generate machine code for an CopyFromReg node or an
85 /// implicit physical register output.
86 void InstrEmitter::
87 EmitCopyFromReg(SDNode *Node, unsigned ResNo, bool IsClone, bool IsCloned,
88  unsigned SrcReg, DenseMap<SDValue, unsigned> &VRBaseMap) {
89  unsigned VRBase = 0;
91  // Just use the input register directly!
92  SDValue Op(Node, ResNo);
93  if (IsClone)
94  VRBaseMap.erase(Op);
95  bool isNew = VRBaseMap.insert(std::make_pair(Op, SrcReg)).second;
96  (void)isNew; // Silence compiler warning.
97  assert(isNew && "Node emitted out of order - early");
98  return;
99  }
100 
101  // If the node is only used by a CopyToReg and the dest reg is a vreg, use
102  // the CopyToReg'd destination register instead of creating a new vreg.
103  bool MatchReg = true;
104  const TargetRegisterClass *UseRC = nullptr;
105  MVT VT = Node->getSimpleValueType(ResNo);
106 
107  // Stick to the preferred register classes for legal types.
108  if (TLI->isTypeLegal(VT))
109  UseRC = TLI->getRegClassFor(VT);
110 
111  if (!IsClone && !IsCloned)
112  for (SDNode *User : Node->uses()) {
113  bool Match = true;
114  if (User->getOpcode() == ISD::CopyToReg &&
115  User->getOperand(2).getNode() == Node &&
116  User->getOperand(2).getResNo() == ResNo) {
117  unsigned DestReg = cast<RegisterSDNode>(User->getOperand(1))->getReg();
119  VRBase = DestReg;
120  Match = false;
121  } else if (DestReg != SrcReg)
122  Match = false;
123  } else {
124  for (unsigned i = 0, e = User->getNumOperands(); i != e; ++i) {
125  SDValue Op = User->getOperand(i);
126  if (Op.getNode() != Node || Op.getResNo() != ResNo)
127  continue;
128  MVT VT = Node->getSimpleValueType(Op.getResNo());
129  if (VT == MVT::Other || VT == MVT::Glue)
130  continue;
131  Match = false;
132  if (User->isMachineOpcode()) {
133  const MCInstrDesc &II = TII->get(User->getMachineOpcode());
134  const TargetRegisterClass *RC = nullptr;
135  if (i+II.getNumDefs() < II.getNumOperands()) {
136  RC = TRI->getAllocatableClass(
137  TII->getRegClass(II, i+II.getNumDefs(), TRI, *MF));
138  }
139  if (!UseRC)
140  UseRC = RC;
141  else if (RC) {
142  const TargetRegisterClass *ComRC =
143  TRI->getCommonSubClass(UseRC, RC, VT.SimpleTy);
144  // If multiple uses expect disjoint register classes, we emit
145  // copies in AddRegisterOperand.
146  if (ComRC)
147  UseRC = ComRC;
148  }
149  }
150  }
151  }
152  MatchReg &= Match;
153  if (VRBase)
154  break;
155  }
156 
157  const TargetRegisterClass *SrcRC = nullptr, *DstRC = nullptr;
158  SrcRC = TRI->getMinimalPhysRegClass(SrcReg, VT);
159 
160  // Figure out the register class to create for the destreg.
161  if (VRBase) {
162  DstRC = MRI->getRegClass(VRBase);
163  } else if (UseRC) {
164  assert(TRI->isTypeLegalForClass(*UseRC, VT) &&
165  "Incompatible phys register def and uses!");
166  DstRC = UseRC;
167  } else {
168  DstRC = TLI->getRegClassFor(VT);
169  }
170 
171  // If all uses are reading from the src physical register and copying the
172  // register is either impossible or very expensive, then don't create a copy.
173  if (MatchReg && SrcRC->getCopyCost() < 0) {
174  VRBase = SrcReg;
175  } else {
176  // Create the reg, emit the copy.
177  VRBase = MRI->createVirtualRegister(DstRC);
178  BuildMI(*MBB, InsertPos, Node->getDebugLoc(), TII->get(TargetOpcode::COPY),
179  VRBase).addReg(SrcReg);
180  }
181 
182  SDValue Op(Node, ResNo);
183  if (IsClone)
184  VRBaseMap.erase(Op);
185  bool isNew = VRBaseMap.insert(std::make_pair(Op, VRBase)).second;
186  (void)isNew; // Silence compiler warning.
187  assert(isNew && "Node emitted out of order - early");
188 }
189 
190 /// getDstOfCopyToRegUse - If the only use of the specified result number of
191 /// node is a CopyToReg, return its destination register. Return 0 otherwise.
192 unsigned InstrEmitter::getDstOfOnlyCopyToRegUse(SDNode *Node,
193  unsigned ResNo) const {
194  if (!Node->hasOneUse())
195  return 0;
196 
197  SDNode *User = *Node->use_begin();
198  if (User->getOpcode() == ISD::CopyToReg &&
199  User->getOperand(2).getNode() == Node &&
200  User->getOperand(2).getResNo() == ResNo) {
201  unsigned Reg = cast<RegisterSDNode>(User->getOperand(1))->getReg();
203  return Reg;
204  }
205  return 0;
206 }
207 
208 void InstrEmitter::CreateVirtualRegisters(SDNode *Node,
209  MachineInstrBuilder &MIB,
210  const MCInstrDesc &II,
211  bool IsClone, bool IsCloned,
212  DenseMap<SDValue, unsigned> &VRBaseMap) {
213  assert(Node->getMachineOpcode() != TargetOpcode::IMPLICIT_DEF &&
214  "IMPLICIT_DEF should have been handled as a special case elsewhere!");
215 
216  unsigned NumResults = CountResults(Node);
217  for (unsigned i = 0; i < II.getNumDefs(); ++i) {
218  // If the specific node value is only used by a CopyToReg and the dest reg
219  // is a vreg in the same register class, use the CopyToReg'd destination
220  // register instead of creating a new vreg.
221  unsigned VRBase = 0;
222  const TargetRegisterClass *RC =
223  TRI->getAllocatableClass(TII->getRegClass(II, i, TRI, *MF));
224  // Always let the value type influence the used register class. The
225  // constraints on the instruction may be too lax to represent the value
226  // type correctly. For example, a 64-bit float (X86::FR64) can't live in
227  // the 32-bit float super-class (X86::FR32).
228  if (i < NumResults && TLI->isTypeLegal(Node->getSimpleValueType(i))) {
229  const TargetRegisterClass *VTRC =
230  TLI->getRegClassFor(Node->getSimpleValueType(i));
231  if (RC)
232  VTRC = TRI->getCommonSubClass(RC, VTRC);
233  if (VTRC)
234  RC = VTRC;
235  }
236 
237  if (II.OpInfo[i].isOptionalDef()) {
238  // Optional def must be a physical register.
239  VRBase = cast<RegisterSDNode>(Node->getOperand(i-NumResults))->getReg();
241  MIB.addReg(VRBase, RegState::Define);
242  }
243 
244  if (!VRBase && !IsClone && !IsCloned)
245  for (SDNode *User : Node->uses()) {
246  if (User->getOpcode() == ISD::CopyToReg &&
247  User->getOperand(2).getNode() == Node &&
248  User->getOperand(2).getResNo() == i) {
249  unsigned Reg = cast<RegisterSDNode>(User->getOperand(1))->getReg();
251  const TargetRegisterClass *RegRC = MRI->getRegClass(Reg);
252  if (RegRC == RC) {
253  VRBase = Reg;
254  MIB.addReg(VRBase, RegState::Define);
255  break;
256  }
257  }
258  }
259  }
260 
261  // Create the result registers for this node and add the result regs to
262  // the machine instruction.
263  if (VRBase == 0) {
264  assert(RC && "Isn't a register operand!");
265  VRBase = MRI->createVirtualRegister(RC);
266  MIB.addReg(VRBase, RegState::Define);
267  }
268 
269  // If this def corresponds to a result of the SDNode insert the VRBase into
270  // the lookup map.
271  if (i < NumResults) {
272  SDValue Op(Node, i);
273  if (IsClone)
274  VRBaseMap.erase(Op);
275  bool isNew = VRBaseMap.insert(std::make_pair(Op, VRBase)).second;
276  (void)isNew; // Silence compiler warning.
277  assert(isNew && "Node emitted out of order - early");
278  }
279  }
280 }
281 
282 /// getVR - Return the virtual register corresponding to the specified result
283 /// of the specified node.
284 unsigned InstrEmitter::getVR(SDValue Op,
285  DenseMap<SDValue, unsigned> &VRBaseMap) {
286  if (Op.isMachineOpcode() &&
287  Op.getMachineOpcode() == TargetOpcode::IMPLICIT_DEF) {
288  // Add an IMPLICIT_DEF instruction before every use.
289  unsigned VReg = getDstOfOnlyCopyToRegUse(Op.getNode(), Op.getResNo());
290  // IMPLICIT_DEF can produce any type of result so its MCInstrDesc
291  // does not include operand register class info.
292  if (!VReg) {
293  const TargetRegisterClass *RC =
295  VReg = MRI->createVirtualRegister(RC);
296  }
297  BuildMI(*MBB, InsertPos, Op.getDebugLoc(),
298  TII->get(TargetOpcode::IMPLICIT_DEF), VReg);
299  return VReg;
300  }
301 
303  assert(I != VRBaseMap.end() && "Node emitted out of order - late");
304  return I->second;
305 }
306 
307 
308 /// AddRegisterOperand - Add the specified register as an operand to the
309 /// specified machine instr. Insert register copies if the register is
310 /// not in the required register class.
311 void
312 InstrEmitter::AddRegisterOperand(MachineInstrBuilder &MIB,
313  SDValue Op,
314  unsigned IIOpNum,
315  const MCInstrDesc *II,
316  DenseMap<SDValue, unsigned> &VRBaseMap,
317  bool IsDebug, bool IsClone, bool IsCloned) {
318  assert(Op.getValueType() != MVT::Other &&
319  Op.getValueType() != MVT::Glue &&
320  "Chain and glue operands should occur at end of operand list!");
321  // Get/emit the operand.
322  unsigned VReg = getVR(Op, VRBaseMap);
323 
324  const MCInstrDesc &MCID = MIB->getDesc();
325  bool isOptDef = IIOpNum < MCID.getNumOperands() &&
326  MCID.OpInfo[IIOpNum].isOptionalDef();
327 
328  // If the instruction requires a register in a different class, create
329  // a new virtual register and copy the value into it, but first attempt to
330  // shrink VReg's register class within reason. For example, if VReg == GR32
331  // and II requires a GR32_NOSP, just constrain VReg to GR32_NOSP.
332  if (II) {
333  const TargetRegisterClass *OpRC = nullptr;
334  if (IIOpNum < II->getNumOperands())
335  OpRC = TII->getRegClass(*II, IIOpNum, TRI, *MF);
336 
337  if (OpRC) {
338  const TargetRegisterClass *ConstrainedRC
339  = MRI->constrainRegClass(VReg, OpRC, MinRCSize);
340  if (!ConstrainedRC) {
341  OpRC = TRI->getAllocatableClass(OpRC);
342  assert(OpRC && "Constraints cannot be fulfilled for allocation");
343  unsigned NewVReg = MRI->createVirtualRegister(OpRC);
344  BuildMI(*MBB, InsertPos, Op.getNode()->getDebugLoc(),
345  TII->get(TargetOpcode::COPY), NewVReg).addReg(VReg);
346  VReg = NewVReg;
347  } else {
348  assert(ConstrainedRC->isAllocatable() &&
349  "Constraining an allocatable VReg produced an unallocatable class?");
350  }
351  }
352  }
353 
354  // If this value has only one use, that use is a kill. This is a
355  // conservative approximation. InstrEmitter does trivial coalescing
356  // with CopyFromReg nodes, so don't emit kill flags for them.
357  // Avoid kill flags on Schedule cloned nodes, since there will be
358  // multiple uses.
359  // Tied operands are never killed, so we need to check that. And that
360  // means we need to determine the index of the operand.
361  bool isKill = Op.hasOneUse() &&
362  Op.getNode()->getOpcode() != ISD::CopyFromReg &&
363  !IsDebug &&
364  !(IsClone || IsCloned);
365  if (isKill) {
366  unsigned Idx = MIB->getNumOperands();
367  while (Idx > 0 &&
368  MIB->getOperand(Idx-1).isReg() &&
369  MIB->getOperand(Idx-1).isImplicit())
370  --Idx;
371  bool isTied = MCID.getOperandConstraint(Idx, MCOI::TIED_TO) != -1;
372  if (isTied)
373  isKill = false;
374  }
375 
376  MIB.addReg(VReg, getDefRegState(isOptDef) | getKillRegState(isKill) |
377  getDebugRegState(IsDebug));
378 }
379 
380 /// AddOperand - Add the specified operand to the specified machine instr. II
381 /// specifies the instruction information for the node, and IIOpNum is the
382 /// operand number (in the II) that we are adding.
383 void InstrEmitter::AddOperand(MachineInstrBuilder &MIB,
384  SDValue Op,
385  unsigned IIOpNum,
386  const MCInstrDesc *II,
387  DenseMap<SDValue, unsigned> &VRBaseMap,
388  bool IsDebug, bool IsClone, bool IsCloned) {
389  if (Op.isMachineOpcode()) {
390  AddRegisterOperand(MIB, Op, IIOpNum, II, VRBaseMap,
391  IsDebug, IsClone, IsCloned);
392  } else if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op)) {
393  MIB.addImm(C->getSExtValue());
394  } else if (ConstantFPSDNode *F = dyn_cast<ConstantFPSDNode>(Op)) {
395  MIB.addFPImm(F->getConstantFPValue());
396  } else if (RegisterSDNode *R = dyn_cast<RegisterSDNode>(Op)) {
397  // Turn additional physreg operands into implicit uses on non-variadic
398  // instructions. This is used by call and return instructions passing
399  // arguments in registers.
400  bool Imp = II && (IIOpNum >= II->getNumOperands() && !II->isVariadic());
401  MIB.addReg(R->getReg(), getImplRegState(Imp));
402  } else if (RegisterMaskSDNode *RM = dyn_cast<RegisterMaskSDNode>(Op)) {
403  MIB.addRegMask(RM->getRegMask());
404  } else if (GlobalAddressSDNode *TGA = dyn_cast<GlobalAddressSDNode>(Op)) {
405  MIB.addGlobalAddress(TGA->getGlobal(), TGA->getOffset(),
406  TGA->getTargetFlags());
407  } else if (BasicBlockSDNode *BBNode = dyn_cast<BasicBlockSDNode>(Op)) {
408  MIB.addMBB(BBNode->getBasicBlock());
409  } else if (FrameIndexSDNode *FI = dyn_cast<FrameIndexSDNode>(Op)) {
410  MIB.addFrameIndex(FI->getIndex());
411  } else if (JumpTableSDNode *JT = dyn_cast<JumpTableSDNode>(Op)) {
412  MIB.addJumpTableIndex(JT->getIndex(), JT->getTargetFlags());
413  } else if (ConstantPoolSDNode *CP = dyn_cast<ConstantPoolSDNode>(Op)) {
414  int Offset = CP->getOffset();
415  unsigned Align = CP->getAlignment();
416  Type *Type = CP->getType();
417  // MachineConstantPool wants an explicit alignment.
418  if (Align == 0) {
419  Align = MF->getDataLayout().getPrefTypeAlignment(Type);
420  if (Align == 0) {
421  // Alignment of vector types. FIXME!
422  Align = MF->getDataLayout().getTypeAllocSize(Type);
423  }
424  }
425 
426  unsigned Idx;
428  if (CP->isMachineConstantPoolEntry())
429  Idx = MCP->getConstantPoolIndex(CP->getMachineCPVal(), Align);
430  else
431  Idx = MCP->getConstantPoolIndex(CP->getConstVal(), Align);
432  MIB.addConstantPoolIndex(Idx, Offset, CP->getTargetFlags());
433  } else if (ExternalSymbolSDNode *ES = dyn_cast<ExternalSymbolSDNode>(Op)) {
434  MIB.addExternalSymbol(ES->getSymbol(), ES->getTargetFlags());
435  } else if (auto *SymNode = dyn_cast<MCSymbolSDNode>(Op)) {
436  MIB.addSym(SymNode->getMCSymbol());
437  } else if (BlockAddressSDNode *BA = dyn_cast<BlockAddressSDNode>(Op)) {
438  MIB.addBlockAddress(BA->getBlockAddress(),
439  BA->getOffset(),
440  BA->getTargetFlags());
441  } else if (TargetIndexSDNode *TI = dyn_cast<TargetIndexSDNode>(Op)) {
442  MIB.addTargetIndex(TI->getIndex(), TI->getOffset(), TI->getTargetFlags());
443  } else {
444  assert(Op.getValueType() != MVT::Other &&
445  Op.getValueType() != MVT::Glue &&
446  "Chain and glue operands should occur at end of operand list!");
447  AddRegisterOperand(MIB, Op, IIOpNum, II, VRBaseMap,
448  IsDebug, IsClone, IsCloned);
449  }
450 }
451 
452 unsigned InstrEmitter::ConstrainForSubReg(unsigned VReg, unsigned SubIdx,
453  MVT VT, const DebugLoc &DL) {
454  const TargetRegisterClass *VRC = MRI->getRegClass(VReg);
455  const TargetRegisterClass *RC = TRI->getSubClassWithSubReg(VRC, SubIdx);
456 
457  // RC is a sub-class of VRC that supports SubIdx. Try to constrain VReg
458  // within reason.
459  if (RC && RC != VRC)
460  RC = MRI->constrainRegClass(VReg, RC, MinRCSize);
461 
462  // VReg has been adjusted. It can be used with SubIdx operands now.
463  if (RC)
464  return VReg;
465 
466  // VReg couldn't be reasonably constrained. Emit a COPY to a new virtual
467  // register instead.
468  RC = TRI->getSubClassWithSubReg(TLI->getRegClassFor(VT), SubIdx);
469  assert(RC && "No legal register class for VT supports that SubIdx");
470  unsigned NewReg = MRI->createVirtualRegister(RC);
471  BuildMI(*MBB, InsertPos, DL, TII->get(TargetOpcode::COPY), NewReg)
472  .addReg(VReg);
473  return NewReg;
474 }
475 
476 /// EmitSubregNode - Generate machine code for subreg nodes.
477 ///
478 void InstrEmitter::EmitSubregNode(SDNode *Node,
479  DenseMap<SDValue, unsigned> &VRBaseMap,
480  bool IsClone, bool IsCloned) {
481  unsigned VRBase = 0;
482  unsigned Opc = Node->getMachineOpcode();
483 
484  // If the node is only used by a CopyToReg and the dest reg is a vreg, use
485  // the CopyToReg'd destination register instead of creating a new vreg.
486  for (SDNode *User : Node->uses()) {
487  if (User->getOpcode() == ISD::CopyToReg &&
488  User->getOperand(2).getNode() == Node) {
489  unsigned DestReg = cast<RegisterSDNode>(User->getOperand(1))->getReg();
491  VRBase = DestReg;
492  break;
493  }
494  }
495  }
496 
497  if (Opc == TargetOpcode::EXTRACT_SUBREG) {
498  // EXTRACT_SUBREG is lowered as %dst = COPY %src:sub. There are no
499  // constraints on the %dst register, COPY can target all legal register
500  // classes.
501  unsigned SubIdx = cast<ConstantSDNode>(Node->getOperand(1))->getZExtValue();
502  const TargetRegisterClass *TRC =
503  TLI->getRegClassFor(Node->getSimpleValueType(0));
504 
505  unsigned Reg;
509  Reg = R->getReg();
510  DefMI = nullptr;
511  } else {
512  Reg = getVR(Node->getOperand(0), VRBaseMap);
513  DefMI = MRI->getVRegDef(Reg);
514  }
515 
516  unsigned SrcReg, DstReg, DefSubIdx;
517  if (DefMI &&
518  TII->isCoalescableExtInstr(*DefMI, SrcReg, DstReg, DefSubIdx) &&
519  SubIdx == DefSubIdx &&
520  TRC == MRI->getRegClass(SrcReg)) {
521  // Optimize these:
522  // r1025 = s/zext r1024, 4
523  // r1026 = extract_subreg r1025, 4
524  // to a copy
525  // r1026 = copy r1024
526  VRBase = MRI->createVirtualRegister(TRC);
527  BuildMI(*MBB, InsertPos, Node->getDebugLoc(),
528  TII->get(TargetOpcode::COPY), VRBase).addReg(SrcReg);
529  MRI->clearKillFlags(SrcReg);
530  } else {
531  // Reg may not support a SubIdx sub-register, and we may need to
532  // constrain its register class or issue a COPY to a compatible register
533  // class.
535  Reg = ConstrainForSubReg(Reg, SubIdx,
536  Node->getOperand(0).getSimpleValueType(),
537  Node->getDebugLoc());
538 
539  // Create the destreg if it is missing.
540  if (VRBase == 0)
541  VRBase = MRI->createVirtualRegister(TRC);
542 
543  // Create the extract_subreg machine instruction.
544  MachineInstrBuilder CopyMI =
545  BuildMI(*MBB, InsertPos, Node->getDebugLoc(),
546  TII->get(TargetOpcode::COPY), VRBase);
548  CopyMI.addReg(Reg, 0, SubIdx);
549  else
550  CopyMI.addReg(TRI->getSubReg(Reg, SubIdx));
551  }
552  } else if (Opc == TargetOpcode::INSERT_SUBREG ||
553  Opc == TargetOpcode::SUBREG_TO_REG) {
554  SDValue N0 = Node->getOperand(0);
555  SDValue N1 = Node->getOperand(1);
556  SDValue N2 = Node->getOperand(2);
557  unsigned SubIdx = cast<ConstantSDNode>(N2)->getZExtValue();
558 
559  // Figure out the register class to create for the destreg. It should be
560  // the largest legal register class supporting SubIdx sub-registers.
561  // RegisterCoalescer will constrain it further if it decides to eliminate
562  // the INSERT_SUBREG instruction.
563  //
564  // %dst = INSERT_SUBREG %src, %sub, SubIdx
565  //
566  // is lowered by TwoAddressInstructionPass to:
567  //
568  // %dst = COPY %src
569  // %dst:SubIdx = COPY %sub
570  //
571  // There is no constraint on the %src register class.
572  //
573  const TargetRegisterClass *SRC = TLI->getRegClassFor(Node->getSimpleValueType(0));
574  SRC = TRI->getSubClassWithSubReg(SRC, SubIdx);
575  assert(SRC && "No register class supports VT and SubIdx for INSERT_SUBREG");
576 
577  if (VRBase == 0 || !SRC->hasSubClassEq(MRI->getRegClass(VRBase)))
578  VRBase = MRI->createVirtualRegister(SRC);
579 
580  // Create the insert_subreg or subreg_to_reg machine instruction.
581  MachineInstrBuilder MIB =
582  BuildMI(*MF, Node->getDebugLoc(), TII->get(Opc), VRBase);
583 
584  // If creating a subreg_to_reg, then the first input operand
585  // is an implicit value immediate, otherwise it's a register
586  if (Opc == TargetOpcode::SUBREG_TO_REG) {
587  const ConstantSDNode *SD = cast<ConstantSDNode>(N0);
588  MIB.addImm(SD->getZExtValue());
589  } else
590  AddOperand(MIB, N0, 0, nullptr, VRBaseMap, /*IsDebug=*/false,
591  IsClone, IsCloned);
592  // Add the subregister being inserted
593  AddOperand(MIB, N1, 0, nullptr, VRBaseMap, /*IsDebug=*/false,
594  IsClone, IsCloned);
595  MIB.addImm(SubIdx);
596  MBB->insert(InsertPos, MIB);
597  } else
598  llvm_unreachable("Node is not insert_subreg, extract_subreg, or subreg_to_reg");
599 
600  SDValue Op(Node, 0);
601  bool isNew = VRBaseMap.insert(std::make_pair(Op, VRBase)).second;
602  (void)isNew; // Silence compiler warning.
603  assert(isNew && "Node emitted out of order - early");
604 }
605 
606 /// EmitCopyToRegClassNode - Generate machine code for COPY_TO_REGCLASS nodes.
607 /// COPY_TO_REGCLASS is just a normal copy, except that the destination
608 /// register is constrained to be in a particular register class.
609 ///
610 void
611 InstrEmitter::EmitCopyToRegClassNode(SDNode *Node,
612  DenseMap<SDValue, unsigned> &VRBaseMap) {
613  unsigned VReg = getVR(Node->getOperand(0), VRBaseMap);
614 
615  // Create the new VReg in the destination class and emit a copy.
616  unsigned DstRCIdx = cast<ConstantSDNode>(Node->getOperand(1))->getZExtValue();
617  const TargetRegisterClass *DstRC =
618  TRI->getAllocatableClass(TRI->getRegClass(DstRCIdx));
619  unsigned NewVReg = MRI->createVirtualRegister(DstRC);
620  BuildMI(*MBB, InsertPos, Node->getDebugLoc(), TII->get(TargetOpcode::COPY),
621  NewVReg).addReg(VReg);
622 
623  SDValue Op(Node, 0);
624  bool isNew = VRBaseMap.insert(std::make_pair(Op, NewVReg)).second;
625  (void)isNew; // Silence compiler warning.
626  assert(isNew && "Node emitted out of order - early");
627 }
628 
629 /// EmitRegSequence - Generate machine code for REG_SEQUENCE nodes.
630 ///
631 void InstrEmitter::EmitRegSequence(SDNode *Node,
632  DenseMap<SDValue, unsigned> &VRBaseMap,
633  bool IsClone, bool IsCloned) {
634  unsigned DstRCIdx = cast<ConstantSDNode>(Node->getOperand(0))->getZExtValue();
635  const TargetRegisterClass *RC = TRI->getRegClass(DstRCIdx);
636  unsigned NewVReg = MRI->createVirtualRegister(TRI->getAllocatableClass(RC));
637  const MCInstrDesc &II = TII->get(TargetOpcode::REG_SEQUENCE);
638  MachineInstrBuilder MIB = BuildMI(*MF, Node->getDebugLoc(), II, NewVReg);
639  unsigned NumOps = Node->getNumOperands();
640  assert((NumOps & 1) == 1 &&
641  "REG_SEQUENCE must have an odd number of operands!");
642  for (unsigned i = 1; i != NumOps; ++i) {
643  SDValue Op = Node->getOperand(i);
644  if ((i & 1) == 0) {
646  // Skip physical registers as they don't have a vreg to get and we'll
647  // insert copies for them in TwoAddressInstructionPass anyway.
649  unsigned SubIdx = cast<ConstantSDNode>(Op)->getZExtValue();
650  unsigned SubReg = getVR(Node->getOperand(i-1), VRBaseMap);
651  const TargetRegisterClass *TRC = MRI->getRegClass(SubReg);
652  const TargetRegisterClass *SRC =
653  TRI->getMatchingSuperRegClass(RC, TRC, SubIdx);
654  if (SRC && SRC != RC) {
655  MRI->setRegClass(NewVReg, SRC);
656  RC = SRC;
657  }
658  }
659  }
660  AddOperand(MIB, Op, i+1, &II, VRBaseMap, /*IsDebug=*/false,
661  IsClone, IsCloned);
662  }
663 
664  MBB->insert(InsertPos, MIB);
665  SDValue Op(Node, 0);
666  bool isNew = VRBaseMap.insert(std::make_pair(Op, NewVReg)).second;
667  (void)isNew; // Silence compiler warning.
668  assert(isNew && "Node emitted out of order - early");
669 }
670 
671 /// EmitDbgValue - Generate machine instruction for a dbg_value node.
672 ///
673 MachineInstr *
675  DenseMap<SDValue, unsigned> &VRBaseMap) {
676  uint64_t Offset = SD->getOffset();
677  MDNode *Var = SD->getVariable();
678  MDNode *Expr = SD->getExpression();
679  DebugLoc DL = SD->getDebugLoc();
680  assert(cast<DILocalVariable>(Var)->isValidLocationForIntrinsic(DL) &&
681  "Expected inlined-at fields to agree");
682 
683  if (SD->getKind() == SDDbgValue::FRAMEIX) {
684  // Stack address; this needs to be lowered in target-dependent fashion.
685  // EmitTargetCodeForFrameDebugValue is responsible for allocation.
686  return BuildMI(*MF, DL, TII->get(TargetOpcode::DBG_VALUE))
687  .addFrameIndex(SD->getFrameIx())
688  .addImm(Offset)
689  .addMetadata(Var)
690  .addMetadata(Expr);
691  }
692  // Otherwise, we're going to create an instruction here.
693  const MCInstrDesc &II = TII->get(TargetOpcode::DBG_VALUE);
694  MachineInstrBuilder MIB = BuildMI(*MF, DL, II);
695  if (SD->getKind() == SDDbgValue::SDNODE) {
696  SDNode *Node = SD->getSDNode();
697  SDValue Op = SDValue(Node, SD->getResNo());
698  // It's possible we replaced this SDNode with other(s) and therefore
699  // didn't generate code for it. It's better to catch these cases where
700  // they happen and transfer the debug info, but trying to guarantee that
701  // in all cases would be very fragile; this is a safeguard for any
702  // that were missed.
704  if (I==VRBaseMap.end())
705  MIB.addReg(0U); // undef
706  else
707  AddOperand(MIB, Op, (*MIB).getNumOperands(), &II, VRBaseMap,
708  /*IsDebug=*/true, /*IsClone=*/false, /*IsCloned=*/false);
709  } else if (SD->getKind() == SDDbgValue::CONST) {
710  const Value *V = SD->getConst();
711  if (const ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
712  if (CI->getBitWidth() > 64)
713  MIB.addCImm(CI);
714  else
715  MIB.addImm(CI->getSExtValue());
716  } else if (const ConstantFP *CF = dyn_cast<ConstantFP>(V)) {
717  MIB.addFPImm(CF);
718  } else {
719  // Could be an Undef. In any case insert an Undef so we can see what we
720  // dropped.
721  MIB.addReg(0U);
722  }
723  } else {
724  // Insert an Undef so we can see what we dropped.
725  MIB.addReg(0U);
726  }
727 
728  // Indirect addressing is indicated by an Imm as the second parameter.
729  if (SD->isIndirect())
730  MIB.addImm(Offset);
731  else {
732  assert(Offset == 0 && "direct value cannot have an offset");
733  MIB.addReg(0U, RegState::Debug);
734  }
735 
736  MIB.addMetadata(Var);
737  MIB.addMetadata(Expr);
738 
739  return &*MIB;
740 }
741 
742 /// EmitMachineNode - Generate machine code for a target-specific node and
743 /// needed dependencies.
744 ///
745 void InstrEmitter::
746 EmitMachineNode(SDNode *Node, bool IsClone, bool IsCloned,
747  DenseMap<SDValue, unsigned> &VRBaseMap) {
748  unsigned Opc = Node->getMachineOpcode();
749 
750  // Handle subreg insert/extract specially
751  if (Opc == TargetOpcode::EXTRACT_SUBREG ||
752  Opc == TargetOpcode::INSERT_SUBREG ||
753  Opc == TargetOpcode::SUBREG_TO_REG) {
754  EmitSubregNode(Node, VRBaseMap, IsClone, IsCloned);
755  return;
756  }
757 
758  // Handle COPY_TO_REGCLASS specially.
759  if (Opc == TargetOpcode::COPY_TO_REGCLASS) {
760  EmitCopyToRegClassNode(Node, VRBaseMap);
761  return;
762  }
763 
764  // Handle REG_SEQUENCE specially.
765  if (Opc == TargetOpcode::REG_SEQUENCE) {
766  EmitRegSequence(Node, VRBaseMap, IsClone, IsCloned);
767  return;
768  }
769 
770  if (Opc == TargetOpcode::IMPLICIT_DEF)
771  // We want a unique VR for each IMPLICIT_DEF use.
772  return;
773 
774  const MCInstrDesc &II = TII->get(Opc);
775  unsigned NumResults = CountResults(Node);
776  unsigned NumDefs = II.getNumDefs();
777  const MCPhysReg *ScratchRegs = nullptr;
778 
779  // Handle STACKMAP and PATCHPOINT specially and then use the generic code.
780  if (Opc == TargetOpcode::STACKMAP || Opc == TargetOpcode::PATCHPOINT) {
781  // Stackmaps do not have arguments and do not preserve their calling
782  // convention. However, to simplify runtime support, they clobber the same
783  // scratch registers as AnyRegCC.
784  unsigned CC = CallingConv::AnyReg;
785  if (Opc == TargetOpcode::PATCHPOINT) {
787  NumDefs = NumResults;
788  }
789  ScratchRegs = TLI->getScratchRegisters((CallingConv::ID) CC);
790  }
791 
792  unsigned NumImpUses = 0;
793  unsigned NodeOperands =
794  countOperands(Node, II.getNumOperands() - NumDefs, NumImpUses);
795  bool HasPhysRegOuts = NumResults > NumDefs && II.getImplicitDefs()!=nullptr;
796 #ifndef NDEBUG
797  unsigned NumMIOperands = NodeOperands + NumResults;
798  if (II.isVariadic())
799  assert(NumMIOperands >= II.getNumOperands() &&
800  "Too few operands for a variadic node!");
801  else
802  assert(NumMIOperands >= II.getNumOperands() &&
803  NumMIOperands <= II.getNumOperands() + II.getNumImplicitDefs() +
804  NumImpUses &&
805  "#operands for dag node doesn't match .td file!");
806 #endif
807 
808  // Create the new machine instruction.
809  MachineInstrBuilder MIB = BuildMI(*MF, Node->getDebugLoc(), II);
810 
811  // Add result register values for things that are defined by this
812  // instruction.
813  if (NumResults)
814  CreateVirtualRegisters(Node, MIB, II, IsClone, IsCloned, VRBaseMap);
815 
816  // Emit all of the actual operands of this instruction, adding them to the
817  // instruction as appropriate.
818  bool HasOptPRefs = NumDefs > NumResults;
819  assert((!HasOptPRefs || !HasPhysRegOuts) &&
820  "Unable to cope with optional defs and phys regs defs!");
821  unsigned NumSkip = HasOptPRefs ? NumDefs - NumResults : 0;
822  for (unsigned i = NumSkip; i != NodeOperands; ++i)
823  AddOperand(MIB, Node->getOperand(i), i-NumSkip+NumDefs, &II,
824  VRBaseMap, /*IsDebug=*/false, IsClone, IsCloned);
825 
826  // Add scratch registers as implicit def and early clobber
827  if (ScratchRegs)
828  for (unsigned i = 0; ScratchRegs[i]; ++i)
829  MIB.addReg(ScratchRegs[i], RegState::ImplicitDefine |
831 
832  // Transfer all of the memory reference descriptions of this instruction.
833  MIB.setMemRefs(cast<MachineSDNode>(Node)->memoperands_begin(),
834  cast<MachineSDNode>(Node)->memoperands_end());
835 
836  // Insert the instruction into position in the block. This needs to
837  // happen before any custom inserter hook is called so that the
838  // hook knows where in the block to insert the replacement code.
839  MBB->insert(InsertPos, MIB);
840 
841  // The MachineInstr may also define physregs instead of virtregs. These
842  // physreg values can reach other instructions in different ways:
843  //
844  // 1. When there is a use of a Node value beyond the explicitly defined
845  // virtual registers, we emit a CopyFromReg for one of the implicitly
846  // defined physregs. This only happens when HasPhysRegOuts is true.
847  //
848  // 2. A CopyFromReg reading a physreg may be glued to this instruction.
849  //
850  // 3. A glued instruction may implicitly use a physreg.
851  //
852  // 4. A glued instruction may use a RegisterSDNode operand.
853  //
854  // Collect all the used physreg defs, and make sure that any unused physreg
855  // defs are marked as dead.
856  SmallVector<unsigned, 8> UsedRegs;
857 
858  // Additional results must be physical register defs.
859  if (HasPhysRegOuts) {
860  for (unsigned i = NumDefs; i < NumResults; ++i) {
861  unsigned Reg = II.getImplicitDefs()[i - NumDefs];
862  if (!Node->hasAnyUseOfValue(i))
863  continue;
864  // This implicitly defined physreg has a use.
865  UsedRegs.push_back(Reg);
866  EmitCopyFromReg(Node, i, IsClone, IsCloned, Reg, VRBaseMap);
867  }
868  }
869 
870  // Scan the glue chain for any used physregs.
871  if (Node->getValueType(Node->getNumValues()-1) == MVT::Glue) {
872  for (SDNode *F = Node->getGluedUser(); F; F = F->getGluedUser()) {
873  if (F->getOpcode() == ISD::CopyFromReg) {
874  UsedRegs.push_back(cast<RegisterSDNode>(F->getOperand(1))->getReg());
875  continue;
876  } else if (F->getOpcode() == ISD::CopyToReg) {
877  // Skip CopyToReg nodes that are internal to the glue chain.
878  continue;
879  }
880  // Collect declared implicit uses.
881  const MCInstrDesc &MCID = TII->get(F->getMachineOpcode());
882  UsedRegs.append(MCID.getImplicitUses(),
883  MCID.getImplicitUses() + MCID.getNumImplicitUses());
884  // In addition to declared implicit uses, we must also check for
885  // direct RegisterSDNode operands.
886  for (unsigned i = 0, e = F->getNumOperands(); i != e; ++i)
887  if (RegisterSDNode *R = dyn_cast<RegisterSDNode>(F->getOperand(i))) {
888  unsigned Reg = R->getReg();
890  UsedRegs.push_back(Reg);
891  }
892  }
893  }
894 
895  // Finally mark unused registers as dead.
896  if (!UsedRegs.empty() || II.getImplicitDefs())
897  MIB->setPhysRegsDeadExcept(UsedRegs, *TRI);
898 
899  // Run post-isel target hook to adjust this instruction if needed.
900  if (II.hasPostISelHook())
901  TLI->AdjustInstrPostInstrSelection(*MIB, Node);
902 }
903 
904 /// EmitSpecialNode - Generate machine code for a target-independent node and
905 /// needed dependencies.
906 void InstrEmitter::
907 EmitSpecialNode(SDNode *Node, bool IsClone, bool IsCloned,
908  DenseMap<SDValue, unsigned> &VRBaseMap) {
909  switch (Node->getOpcode()) {
910  default:
911 #ifndef NDEBUG
912  Node->dump();
913 #endif
914  llvm_unreachable("This target-independent node should have been selected!");
915  case ISD::EntryToken:
916  llvm_unreachable("EntryToken should have been excluded from the schedule!");
917  case ISD::MERGE_VALUES:
918  case ISD::TokenFactor: // fall thru
919  break;
920  case ISD::CopyToReg: {
921  unsigned SrcReg;
922  SDValue SrcVal = Node->getOperand(2);
923  if (RegisterSDNode *R = dyn_cast<RegisterSDNode>(SrcVal))
924  SrcReg = R->getReg();
925  else
926  SrcReg = getVR(SrcVal, VRBaseMap);
927 
928  unsigned DestReg = cast<RegisterSDNode>(Node->getOperand(1))->getReg();
929  if (SrcReg == DestReg) // Coalesced away the copy? Ignore.
930  break;
931 
932  BuildMI(*MBB, InsertPos, Node->getDebugLoc(), TII->get(TargetOpcode::COPY),
933  DestReg).addReg(SrcReg);
934  break;
935  }
936  case ISD::CopyFromReg: {
937  unsigned SrcReg = cast<RegisterSDNode>(Node->getOperand(1))->getReg();
938  EmitCopyFromReg(Node, 0, IsClone, IsCloned, SrcReg, VRBaseMap);
939  break;
940  }
941  case ISD::EH_LABEL: {
942  MCSymbol *S = cast<EHLabelSDNode>(Node)->getLabel();
943  BuildMI(*MBB, InsertPos, Node->getDebugLoc(),
944  TII->get(TargetOpcode::EH_LABEL)).addSym(S);
945  break;
946  }
947 
948  case ISD::LIFETIME_START:
949  case ISD::LIFETIME_END: {
950  unsigned TarOp = (Node->getOpcode() == ISD::LIFETIME_START) ?
952 
954  BuildMI(*MBB, InsertPos, Node->getDebugLoc(), TII->get(TarOp))
955  .addFrameIndex(FI->getIndex());
956  break;
957  }
958 
959  case ISD::INLINEASM: {
960  unsigned NumOps = Node->getNumOperands();
961  if (Node->getOperand(NumOps-1).getValueType() == MVT::Glue)
962  --NumOps; // Ignore the glue operand.
963 
964  // Create the inline asm machine instruction.
965  MachineInstrBuilder MIB = BuildMI(*MF, Node->getDebugLoc(),
967 
968  // Add the asm string as an external symbol operand.
969  SDValue AsmStrV = Node->getOperand(InlineAsm::Op_AsmString);
970  const char *AsmStr = cast<ExternalSymbolSDNode>(AsmStrV)->getSymbol();
971  MIB.addExternalSymbol(AsmStr);
972 
973  // Add the HasSideEffect, isAlignStack, AsmDialect, MayLoad and MayStore
974  // bits.
975  int64_t ExtraInfo =
976  cast<ConstantSDNode>(Node->getOperand(InlineAsm::Op_ExtraInfo))->
977  getZExtValue();
978  MIB.addImm(ExtraInfo);
979 
980  // Remember to operand index of the group flags.
981  SmallVector<unsigned, 8> GroupIdx;
982 
983  // Remember registers that are part of early-clobber defs.
985 
986  // Add all of the operand registers to the instruction.
987  for (unsigned i = InlineAsm::Op_FirstOperand; i != NumOps;) {
988  unsigned Flags =
989  cast<ConstantSDNode>(Node->getOperand(i))->getZExtValue();
990  const unsigned NumVals = InlineAsm::getNumOperandRegisters(Flags);
991 
992  GroupIdx.push_back(MIB->getNumOperands());
993  MIB.addImm(Flags);
994  ++i; // Skip the ID value.
995 
996  switch (InlineAsm::getKind(Flags)) {
997  default: llvm_unreachable("Bad flags!");
999  for (unsigned j = 0; j != NumVals; ++j, ++i) {
1000  unsigned Reg = cast<RegisterSDNode>(Node->getOperand(i))->getReg();
1001  // FIXME: Add dead flags for physical and virtual registers defined.
1002  // For now, mark physical register defs as implicit to help fast
1003  // regalloc. This makes inline asm look a lot like calls.
1004  MIB.addReg(Reg, RegState::Define |
1006  }
1007  break;
1010  for (unsigned j = 0; j != NumVals; ++j, ++i) {
1011  unsigned Reg = cast<RegisterSDNode>(Node->getOperand(i))->getReg();
1014  ECRegs.push_back(Reg);
1015  }
1016  break;
1017  case InlineAsm::Kind_RegUse: // Use of register.
1018  case InlineAsm::Kind_Imm: // Immediate.
1019  case InlineAsm::Kind_Mem: // Addressing mode.
1020  // The addressing mode has been selected, just add all of the
1021  // operands to the machine instruction.
1022  for (unsigned j = 0; j != NumVals; ++j, ++i)
1023  AddOperand(MIB, Node->getOperand(i), 0, nullptr, VRBaseMap,
1024  /*IsDebug=*/false, IsClone, IsCloned);
1025 
1026  // Manually set isTied bits.
1028  unsigned DefGroup = 0;
1029  if (InlineAsm::isUseOperandTiedToDef(Flags, DefGroup)) {
1030  unsigned DefIdx = GroupIdx[DefGroup] + 1;
1031  unsigned UseIdx = GroupIdx.back() + 1;
1032  for (unsigned j = 0; j != NumVals; ++j)
1033  MIB->tieOperands(DefIdx + j, UseIdx + j);
1034  }
1035  }
1036  break;
1037  }
1038  }
1039 
1040  // GCC inline assembly allows input operands to also be early-clobber
1041  // output operands (so long as the operand is written only after it's
1042  // used), but this does not match the semantics of our early-clobber flag.
1043  // If an early-clobber operand register is also an input operand register,
1044  // then remove the early-clobber flag.
1045  for (unsigned Reg : ECRegs) {
1046  if (MIB->readsRegister(Reg, TRI)) {
1047  MachineOperand *MO = MIB->findRegisterDefOperand(Reg, false, TRI);
1048  assert(MO && "No def operand for clobbered register?");
1049  MO->setIsEarlyClobber(false);
1050  }
1051  }
1052 
1053  // Get the mdnode from the asm if it exists and add it to the instruction.
1055  const MDNode *MD = cast<MDNodeSDNode>(MDV)->getMD();
1056  if (MD)
1057  MIB.addMetadata(MD);
1058 
1059  MBB->insert(InsertPos, MIB);
1060  break;
1061  }
1062  }
1063 }
1064 
1065 /// InstrEmitter - Construct an InstrEmitter and set it to start inserting
1066 /// at the given position in the given block.
1068  MachineBasicBlock::iterator insertpos)
1069  : MF(mbb->getParent()), MRI(&MF->getRegInfo()),
1070  TII(MF->getSubtarget().getInstrInfo()),
1071  TRI(MF->getSubtarget().getRegisterInfo()),
1072  TLI(MF->getSubtarget().getTargetLowering()), MBB(mbb),
1073  InsertPos(insertpos) {}
uint64_t CallInst * C
unsigned getNumImplicitUses() const
Return the number of implicit uses this instruction has.
Definition: MCInstrDesc.h:515
const TargetRegisterClass * getCommonSubClass(const TargetRegisterClass *A, const TargetRegisterClass *B, const MVT::SimpleValueType SVT=MVT::SimpleValueType::Any) const
Find the largest common subclass of A and B.
const MachineInstrBuilder & addMetadata(const MDNode *MD) const
void push_back(const T &Elt)
Definition: SmallVector.h:212
EVT getValueType() const
Return the ValueType of the referenced return value.
The MachineConstantPool class keeps track of constants referenced by a function which must be spilled...
unsigned getOpcode() const
Return the SelectionDAG opcode value for this node.
InstrEmitter(MachineBasicBlock *mbb, MachineBasicBlock::iterator insertpos)
InstrEmitter - Construct an InstrEmitter and set it to start inserting at the given position in the g...
const TargetRegisterClass * getRegClass(unsigned Reg) const
Return the register class of the specified virtual register.
unsigned getNumImplicitDefs() const
Return the number of implicit defs this instruct has.
Definition: MCInstrDesc.h:537
Compute iterated dominance frontiers using a linear time algorithm.
Definition: AllocatorList.h:24
MachineOperand * findRegisterDefOperand(unsigned Reg, bool isDead=false, const TargetRegisterInfo *TRI=nullptr)
Wrapper for findRegisterDefOperandIdx, it returns a pointer to the MachineOperand rather than an inde...
Definition: MachineInstr.h:976
SDNode * getSDNode() const
MCSymbol - Instances of this class represent a symbol name in the MC file, and MCSymbols are created ...
Definition: MCSymbol.h:42
unsigned createVirtualRegister(const TargetRegisterClass *RegClass)
createVirtualRegister - Create and return a new virtual register in the function with the specified r...
EVT getValueType(unsigned ResNo) const
Return the type of a specified result.
const MCPhysReg * getImplicitUses() const
Return a list of registers that are potentially read by any instance of this machine instruction...
Definition: MCInstrDesc.h:512
Describe properties that are true of each instruction in the target description file.
Definition: MCInstrDesc.h:163
static bool isVirtualRegister(unsigned Reg)
Return true if the specified register number is in the virtual register namespace.
Completely target-dependent object reference.
const Value * getConst() const
static unsigned CountResults(SDNode *Node)
CountResults - The results of target nodes have register or immediate operands first, then an optional chain, and optional flag operands (which do not go into the machine instrs.)
virtual const TargetRegisterClass * getRegClassFor(MVT VT) const
Return the register class that should be used for the specified value type.
A debug info location.
Definition: DebugLoc.h:34
Metadata node.
Definition: Metadata.h:862
MVT getSimpleValueType(unsigned ResNo) const
Return the type of a specified result as a simple type.
SDNode * getNode() const
get the SDNode which holds the desired result
const MachineInstrBuilder & addGlobalAddress(const GlobalValue *GV, int64_t Offset=0, unsigned char TargetFlags=0) const
const MachineInstrBuilder & addTargetIndex(unsigned Idx, int64_t Offset=0, unsigned char TargetFlags=0) const
const DebugLoc & getDebugLoc() const
Return the source location info.
EntryToken - This is the marker used to indicate the start of a region.
Definition: ISDOpcodes.h:45
static bool isUseOperandTiedToDef(unsigned Flag, unsigned &Idx)
isUseOperandTiedToDef - Return true if the flag of the inline asm operand indicates it is an use oper...
Definition: InlineAsm.h:342
bool hasOneUse() const
Return true if there is exactly one node using value ResNo of Node.
const DebugLoc & getDebugLoc() const
unsigned getResNo() const
const TargetRegisterClass * getRegClass(unsigned i) const
Returns the register class associated with the enumeration value.
const unsigned MinRCSize
MinRCSize - Smallest register class we allow when constraining virtual registers. ...
std::pair< iterator, bool > insert(const std::pair< KeyT, ValueT > &KV)
Definition: DenseMap.h:176
bool hasOneUse() const
Return true if there is exactly one use of this node.
unsigned getFrameIx() const
This file declares the MachineConstantPool class which is an abstract constant pool to keep track of ...
unsigned getNumOperands() const
Return the number of declared MachineOperands for this MachineInstruction.
Definition: MCInstrDesc.h:210
unsigned getNumOperands() const
Access to explicit operands of the instruction.
Definition: MachineInstr.h:282
CopyToReg - This node has three operands: a chain, a register number to set to this value...
Definition: ISDOpcodes.h:170
unsigned SubReg
Reg
All possible values of the reg field in the ModR/M byte.
SimpleValueType SimpleTy
virtual const TargetRegisterClass * getSubClassWithSubReg(const TargetRegisterClass *RC, unsigned Idx) const
Returns the largest legal sub-class of RC that supports the sub-register index Idx.
INLINEASM - Represents an inline asm block.
Definition: ISDOpcodes.h:633
MachineInstr * getVRegDef(unsigned Reg) const
getVRegDef - Return the machine instr that defines the specified virtual register or null if none is ...
void setIsEarlyClobber(bool Val=true)
const MCInstrDesc & getDesc() const
Returns the target instruction descriptor of this MachineInstr.
Definition: MachineInstr.h:276
#define F(x, y, z)
Definition: MD5.cpp:55
void clearKillFlags(unsigned Reg) const
clearKillFlags - Iterate over all the uses of the given register and clear the kill flag from the Mac...
const TargetRegisterClass * getRegClass(const MCInstrDesc &TID, unsigned OpNum, const TargetRegisterInfo *TRI, const MachineFunction &MF) const
Given a machine instruction descriptor, returns the register class constraint for OpNum...
MDNode * getVariable() const
const MachineInstrBuilder & addFPImm(const ConstantFP *Val) const
DbgValueKind getKind() const
instr_iterator insert(instr_iterator I, MachineInstr *M)
Insert MI into the instruction list before I, possibly inside a bundle.
bool isTypeLegalForClass(const TargetRegisterClass &RC, MVT T) const
Return true if the given TargetRegisterClass has the ValueType T.
Expected< const typename ELFT::Sym * > getSymbol(typename ELFT::SymRange Symbols, uint32_t Index)
Definition: ELF.h:243
const TargetRegisterClass * constrainRegClass(unsigned Reg, const TargetRegisterClass *RC, unsigned MinNumRegs=0)
constrainRegClass - Constrain the register class of the specified virtual register to be a common sub...
Value * getOperand(unsigned i) const
Definition: User.h:154
const DataLayout & getDataLayout() const
Return the DataLayout attached to the Module associated to this MF.
unsigned getKillRegState(bool B)
uint16_t MCPhysReg
An unsigned integer type large enough to represent all physical registers, but not necessarily virtua...
unsigned getDebugRegState(bool B)
This corresponds to the llvm.lifetime.
Definition: ISDOpcodes.h:794
MVT getSimpleValueType() const
Return the simple ValueType of the referenced return value.
unsigned getDefRegState(bool B)
unsigned getNumValues() const
Return the number of values defined/returned by this operator.
MachineInstrBuilder BuildMI(MachineFunction &MF, const DebugLoc &DL, const MCInstrDesc &MCID)
Builder interface. Specify how to create the initial instruction itself.
const MCPhysReg * getImplicitDefs() const
Return a list of registers that are potentially written by any instance of this machine instruction...
Definition: MCInstrDesc.h:534
use_iterator use_begin() const
Provide iteration support to walk over all uses of an SDNode.
const MachineInstrBuilder & addBlockAddress(const BlockAddress *BA, int64_t Offset=0, unsigned char TargetFlags=0) const
Machine Value Type.
const MachineInstrBuilder & addCImm(const ConstantInt *Val) const
bool isOptionalDef() const
Set if this operand is a optional def.
Definition: MCInstrDesc.h:99
The instances of the Type class are immutable: once they are created, they are never changed...
Definition: Type.h:46
bool isVariadic() const
Return true if this instruction can have a variable number of operands.
Definition: MCInstrDesc.h:234
bool hasAnyUseOfValue(unsigned Value) const
Return true if there are any use of the indicated value.
bool isMachineOpcode() const
SDNode * getGluedUser() const
If this node has a glue value with a user, return the user (there is at most one).
const SDValue & getOperand(unsigned Num) const
ConstantFP - Floating Point Values [float, double].
Definition: Constants.h:264
unsigned getSubReg(unsigned Reg, unsigned Idx) const
Returns the physical register number of sub-register "Index" for physical register RegNo...
static unsigned getNumOperandRegisters(unsigned Flag)
getNumOperandRegisters - Extract the number of registers field from the inline asm operand flag...
Definition: InlineAsm.h:336
unsigned getPrefTypeAlignment(Type *Ty) const
Returns the preferred stack/global alignment for the specified type.
Definition: DataLayout.cpp:692
unsigned getMachineOpcode() const
const MachineInstrBuilder & addRegMask(const uint32_t *Mask) const
static unsigned getKind(unsigned Flags)
Definition: InlineAsm.h:325
virtual const TargetRegisterClass * getMatchingSuperRegClass(const TargetRegisterClass *A, const TargetRegisterClass *B, unsigned Idx) const
Return a subclass of the specified register class A so that each register in it has a sub-register of...
const MachineInstrBuilder & addSym(MCSymbol *Sym, unsigned char TargetFlags=0) const
MachineConstantPool * getConstantPool()
getConstantPool - Return the constant pool object for the current function.
const MachineInstrBuilder & addFrameIndex(int Idx) const
DebugLoc getDebugLoc() const
unsigned getNumOperands() const
Return the number of values used by this operation.
#define llvm_unreachable(msg)
Marks that the current location is not supposed to be reachable.
bool hasSubClassEq(const TargetRegisterClass *RC) const
Returns true if RC is a sub-class of or equal to this class.
EH_LABEL - Represents a label in mid basic block used to track locations needed for debug and excepti...
Definition: ISDOpcodes.h:638
virtual const MCPhysReg * getScratchRegisters(CallingConv::ID CC) const
Returns a 0 terminated array of registers that can be safely used as scratch registers.
int getOperandConstraint(unsigned OpNum, MCOI::OperandConstraint Constraint) const
Returns the value of the specific constraint if it is set.
Definition: MCInstrDesc.h:187
TokenFactor - This node takes multiple tokens as input and produces a single token result...
Definition: ISDOpcodes.h:50
void dump() const
Dump this node, for debugging.
unsigned getNumOperands() const
Definition: User.h:176
This is the shared class of boolean and integer constants.
Definition: Constants.h:84
MachineOperand class - Representation of each machine instruction operand.
MachineInstrBuilder MachineInstrBuilder & DefMI
int getCopyCost() const
Return the cost of copying a value between two registers in this class.
MDNode * getExpression() const
const MachineInstrBuilder & addConstantPoolIndex(unsigned Idx, int Offset=0, unsigned char TargetFlags=0) const
const size_t N
virtual bool isCoalescableExtInstr(const MachineInstr &MI, unsigned &SrcReg, unsigned &DstReg, unsigned &SubIdx) const
Return true if the instruction is a "coalescable" extension instruction.
unsigned getNumDefs() const
Return the number of MachineOperands that are register definitions.
Definition: MCInstrDesc.h:225
Represents one node in the SelectionDAG.
virtual void AdjustInstrPostInstrSelection(MachineInstr &MI, SDNode *Node) const
This method should be implemented by targets that mark instructions with the &#39;hasPostISelHook&#39; flag...
bool isTypeLegal(EVT VT) const
Return true if the target has native support for the specified value type.
iterator_range< use_iterator > uses()
static unsigned getReg(const void *D, unsigned RC, unsigned RegNo)
bool readsRegister(unsigned Reg, const TargetRegisterInfo *TRI=nullptr) const
Return true if the MachineInstr reads the specified register.
Definition: MachineInstr.h:889
void append(in_iter in_start, in_iter in_end)
Add the specified range to the end of the SmallVector.
Definition: SmallVector.h:398
uint64_t getTypeAllocSize(Type *Ty) const
Returns the offset in bytes between successive objects of the specified type, including alignment pad...
Definition: DataLayout.h:405
static std::vector< std::string > Flags
Definition: FlagsTest.cpp:8
Representation of each machine instruction.
Definition: MachineInstr.h:59
static bool isPhysicalRegister(unsigned Reg)
Return true if the specified register number is in the physical register namespace.
const MachineInstrBuilder & addImm(int64_t Val) const
Add a new immediate operand.
LLVM_NODISCARD bool empty() const
Definition: SmallVector.h:61
static unsigned countOperands(SDNode *Node, unsigned NumExpUses, unsigned &NumImpUses)
countOperands - The inputs to target nodes have any actual inputs first, followed by an optional chai...
const MCInstrDesc & get(unsigned Opcode) const
Return the machine instruction descriptor that corresponds to the specified instruction opcode...
Definition: MCInstrInfo.h:45
const MachineInstrBuilder & addExternalSymbol(const char *FnName, unsigned char TargetFlags=0) const
#define I(x, y, z)
Definition: MD5.cpp:58
unsigned getImplRegState(bool B)
constexpr char Align[]
Key for Kernel::Arg::Metadata::mAlign.
LLVM_NODISCARD std::enable_if<!is_simple_type< Y >::value, typename cast_retty< X, const Y >::ret_type >::type dyn_cast(const Y &Val)
Definition: Casting.h:323
const MachineInstrBuilder & addReg(unsigned RegNo, unsigned flags=0, unsigned SubReg=0) const
Add a new virtual register operand.
bool isAllocatable() const
Return true if this register class may be used to create virtual registers.
uint64_t getOffset() const
CopyFromReg - This node indicates that the input value is a virtual or physical register that is defi...
Definition: ISDOpcodes.h:175
const TargetRegisterClass * getMinimalPhysRegClass(unsigned Reg, MVT VT=MVT::Other) const
Returns the Register Class of a physical register of the given type, picking the most sub register cl...
bool isReg() const
isReg - Tests if this is a MO_Register operand.
const MachineInstrBuilder & addJumpTableIndex(unsigned Idx, unsigned char TargetFlags=0) const
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
unsigned getReg() const
MachineInstr * EmitDbgValue(SDDbgValue *SD, DenseMap< SDValue, unsigned > &VRBaseMap)
EmitDbgValue - Generate machine instruction for a dbg_value node.
const TargetRegisterClass * getAllocatableClass(const TargetRegisterClass *RC) const
Return the maximal subclass of the given register class that is allocatable or NULL.
LLVM Value Representation.
Definition: Value.h:73
uint64_t getConstantOperandVal(unsigned Num) const
Helper method returns the integer value of a ConstantSDNode operand.
unsigned getResNo() const
get the index which selects a specific result in the SDNode
unsigned getMachineOpcode() const
This may only be called if isMachineOpcode returns true.
const MCOperandInfo * OpInfo
Definition: MCInstrDesc.h:174
static const Function * getParent(const Value *V)
void setRegClass(unsigned Reg, const TargetRegisterClass *RC)
setRegClass - Set the register class of the specified virtual register.
MERGE_VALUES - This node takes multiple discrete operands and returns them all as its individual resu...
Definition: ISDOpcodes.h:197
unsigned getNumOperands() const
bool isIndirect() const
const MachineInstrBuilder & addMBB(MachineBasicBlock *MBB, unsigned char TargetFlags=0) const
uint64_t getZExtValue() const
const MachineOperand & getOperand(unsigned i) const
Definition: MachineInstr.h:284
Unlike LLVM values, Selection DAG nodes may return multiple values as the result of a computation...
SDDbgValue - Holds the information from a dbg_value node through SDISel.
unsigned getConstantPoolIndex(const Constant *C, unsigned Alignment)
getConstantPoolIndex - Create a new entry in the constant pool or return an existing one...
This file describes how to lower LLVM code to machine code.
bool isImplicit() const
void tieOperands(unsigned DefIdx, unsigned UseIdx)
Add a tie between the register operands at DefIdx and UseIdx.