1 //===- CodeGen/MachineInstrBuilder.h - Simplify creation of MIs --*- 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 exposes a function named BuildMI, which is useful for dramatically
11 // simplifying how MachineInstr's are created. It allows use of code like this:
12 //
13 // M = BuildMI(MBB, MI, DL, TII.get(X86::ADD8rr), Dst)
14 // .addReg(argVal1)
15 // .addReg(argVal2);
16 //
17 //===----------------------------------------------------------------------===//
18
19 #ifndef LLVM_CODEGEN_MACHINEINSTRBUILDER_H
20 #define LLVM_CODEGEN_MACHINEINSTRBUILDER_H
21
22 #include "llvm/ADT/ArrayRef.h"
23 #include "llvm/CodeGen/GlobalISel/Utils.h"
24 #include "llvm/CodeGen/MachineBasicBlock.h"
25 #include "llvm/CodeGen/MachineFunction.h"
26 #include "llvm/CodeGen/MachineInstr.h"
27 #include "llvm/CodeGen/MachineInstrBundle.h"
28 #include "llvm/CodeGen/MachineOperand.h"
29 #include "llvm/CodeGen/TargetRegisterInfo.h"
30 #include "llvm/IR/InstrTypes.h"
31 #include "llvm/IR/Intrinsics.h"
32 #include "llvm/Support/ErrorHandling.h"
33 #include <cassert>
34 #include <cstdint>
35 #include <utility>
36
37 namespace llvm {
38
39 class MCInstrDesc;
40 class MDNode;
41
42 namespace RegState {
43
44 enum {
45 Define = 0x2,
46 Implicit = 0x4,
47 Kill = 0x8,
48 Dead = 0x10,
49 Undef = 0x20,
50 EarlyClobber = 0x40,
51 Debug = 0x80,
52 InternalRead = 0x100,
53 Renamable = 0x200,
54 DefineNoRead = Define | Undef,
55 ImplicitDefine = Implicit | Define,
56 ImplicitKill = Implicit | Kill
57 };
58
59 } // end namespace RegState
60
61 class MachineInstrBuilder {
62 MachineFunction *MF = nullptr;
63 MachineInstr *MI = nullptr;
64
65 public:
66 MachineInstrBuilder() = default;
67
68 /// Create a MachineInstrBuilder for manipulating an existing instruction.
69 /// F must be the machine function that was used to allocate I.
MachineInstrBuilder(MachineFunction & F,MachineInstr * I)70 MachineInstrBuilder(MachineFunction &F, MachineInstr *I) : MF(&F), MI(I) {}
MachineInstrBuilder(MachineFunction & F,MachineBasicBlock::iterator I)71 MachineInstrBuilder(MachineFunction &F, MachineBasicBlock::iterator I)
72 : MF(&F), MI(&*I) {}
73
74 /// Allow automatic conversion to the machine instruction we are working on.
75 operator MachineInstr*() const { return MI; }
76 MachineInstr *operator->() const { return MI; }
iterator()77 operator MachineBasicBlock::iterator() const { return MI; }
78
79 /// If conversion operators fail, use this method to get the MachineInstr
80 /// explicitly.
getInstr()81 MachineInstr *getInstr() const { return MI; }
82
83 /// Add a new virtual register operand.
84 const MachineInstrBuilder &addReg(unsigned RegNo, unsigned flags = 0,
85 unsigned SubReg = 0) const {
86 assert((flags & 0x1) == 0 &&
87 "Passing in 'true' to addReg is forbidden! Use enums instead.");
88 MI->addOperand(*MF, MachineOperand::CreateReg(RegNo,
89 flags & RegState::Define,
90 flags & RegState::Implicit,
91 flags & RegState::Kill,
92 flags & RegState::Dead,
93 flags & RegState::Undef,
94 flags & RegState::EarlyClobber,
95 SubReg,
96 flags & RegState::Debug,
97 flags & RegState::InternalRead,
98 flags & RegState::Renamable));
99 return *this;
100 }
101
102 /// Add a virtual register definition operand.
103 const MachineInstrBuilder &addDef(unsigned RegNo, unsigned Flags = 0,
104 unsigned SubReg = 0) const {
105 return addReg(RegNo, Flags | RegState::Define, SubReg);
106 }
107
108 /// Add a virtual register use operand. It is an error for Flags to contain
109 /// `RegState::Define` when calling this function.
110 const MachineInstrBuilder &addUse(unsigned RegNo, unsigned Flags = 0,
111 unsigned SubReg = 0) const {
112 assert(!(Flags & RegState::Define) &&
113 "Misleading addUse defines register, use addReg instead.");
114 return addReg(RegNo, Flags, SubReg);
115 }
116
117 /// Add a new immediate operand.
addImm(int64_t Val)118 const MachineInstrBuilder &addImm(int64_t Val) const {
119 MI->addOperand(*MF, MachineOperand::CreateImm(Val));
120 return *this;
121 }
122
addCImm(const ConstantInt * Val)123 const MachineInstrBuilder &addCImm(const ConstantInt *Val) const {
124 MI->addOperand(*MF, MachineOperand::CreateCImm(Val));
125 return *this;
126 }
127
addFPImm(const ConstantFP * Val)128 const MachineInstrBuilder &addFPImm(const ConstantFP *Val) const {
129 MI->addOperand(*MF, MachineOperand::CreateFPImm(Val));
130 return *this;
131 }
132
133 const MachineInstrBuilder &addMBB(MachineBasicBlock *MBB,
134 unsigned char TargetFlags = 0) const {
135 MI->addOperand(*MF, MachineOperand::CreateMBB(MBB, TargetFlags));
136 return *this;
137 }
138
addFrameIndex(int Idx)139 const MachineInstrBuilder &addFrameIndex(int Idx) const {
140 MI->addOperand(*MF, MachineOperand::CreateFI(Idx));
141 return *this;
142 }
143
144 const MachineInstrBuilder &addConstantPoolIndex(unsigned Idx,
145 int Offset = 0,
146 unsigned char TargetFlags = 0) const {
147 MI->addOperand(*MF, MachineOperand::CreateCPI(Idx, Offset, TargetFlags));
148 return *this;
149 }
150
151 const MachineInstrBuilder &addTargetIndex(unsigned Idx, int64_t Offset = 0,
152 unsigned char TargetFlags = 0) const {
153 MI->addOperand(*MF, MachineOperand::CreateTargetIndex(Idx, Offset,
154 TargetFlags));
155 return *this;
156 }
157
158 const MachineInstrBuilder &addJumpTableIndex(unsigned Idx,
159 unsigned char TargetFlags = 0) const {
160 MI->addOperand(*MF, MachineOperand::CreateJTI(Idx, TargetFlags));
161 return *this;
162 }
163
164 const MachineInstrBuilder &addGlobalAddress(const GlobalValue *GV,
165 int64_t Offset = 0,
166 unsigned char TargetFlags = 0) const {
167 MI->addOperand(*MF, MachineOperand::CreateGA(GV, Offset, TargetFlags));
168 return *this;
169 }
170
171 const MachineInstrBuilder &addExternalSymbol(const char *FnName,
172 unsigned char TargetFlags = 0) const {
173 MI->addOperand(*MF, MachineOperand::CreateES(FnName, TargetFlags));
174 return *this;
175 }
176
177 const MachineInstrBuilder &addBlockAddress(const BlockAddress *BA,
178 int64_t Offset = 0,
179 unsigned char TargetFlags = 0) const {
180 MI->addOperand(*MF, MachineOperand::CreateBA(BA, Offset, TargetFlags));
181 return *this;
182 }
183
addRegMask(const uint32_t * Mask)184 const MachineInstrBuilder &addRegMask(const uint32_t *Mask) const {
185 MI->addOperand(*MF, MachineOperand::CreateRegMask(Mask));
186 return *this;
187 }
188
addMemOperand(MachineMemOperand * MMO)189 const MachineInstrBuilder &addMemOperand(MachineMemOperand *MMO) const {
190 MI->addMemOperand(*MF, MMO);
191 return *this;
192 }
193
setMemRefs(MachineInstr::mmo_iterator b,MachineInstr::mmo_iterator e)194 const MachineInstrBuilder &setMemRefs(MachineInstr::mmo_iterator b,
195 MachineInstr::mmo_iterator e) const {
196 MI->setMemRefs(b, e);
197 return *this;
198 }
199
setMemRefs(std::pair<MachineInstr::mmo_iterator,unsigned> MemOperandsRef)200 const MachineInstrBuilder &setMemRefs(std::pair<MachineInstr::mmo_iterator,
201 unsigned> MemOperandsRef) const {
202 MI->setMemRefs(MemOperandsRef);
203 return *this;
204 }
205
add(const MachineOperand & MO)206 const MachineInstrBuilder &add(const MachineOperand &MO) const {
207 MI->addOperand(*MF, MO);
208 return *this;
209 }
210
add(ArrayRef<MachineOperand> MOs)211 const MachineInstrBuilder &add(ArrayRef<MachineOperand> MOs) const {
212 for (const MachineOperand &MO : MOs) {
213 MI->addOperand(*MF, MO);
214 }
215 return *this;
216 }
217
addMetadata(const MDNode * MD)218 const MachineInstrBuilder &addMetadata(const MDNode *MD) const {
219 MI->addOperand(*MF, MachineOperand::CreateMetadata(MD));
220 assert((MI->isDebugValue() ? static_cast<bool>(MI->getDebugVariable())
221 : true) &&
222 "first MDNode argument of a DBG_VALUE not a variable");
223 assert((MI->isDebugLabel() ? static_cast<bool>(MI->getDebugLabel())
224 : true) &&
225 "first MDNode argument of a DBG_LABEL not a label");
226 return *this;
227 }
228
addCFIIndex(unsigned CFIIndex)229 const MachineInstrBuilder &addCFIIndex(unsigned CFIIndex) const {
230 MI->addOperand(*MF, MachineOperand::CreateCFIIndex(CFIIndex));
231 return *this;
232 }
233
addIntrinsicID(Intrinsic::ID ID)234 const MachineInstrBuilder &addIntrinsicID(Intrinsic::ID ID) const {
235 MI->addOperand(*MF, MachineOperand::CreateIntrinsicID(ID));
236 return *this;
237 }
238
addPredicate(CmpInst::Predicate Pred)239 const MachineInstrBuilder &addPredicate(CmpInst::Predicate Pred) const {
240 MI->addOperand(*MF, MachineOperand::CreatePredicate(Pred));
241 return *this;
242 }
243
244 const MachineInstrBuilder &addSym(MCSymbol *Sym,
245 unsigned char TargetFlags = 0) const {
246 MI->addOperand(*MF, MachineOperand::CreateMCSymbol(Sym, TargetFlags));
247 return *this;
248 }
249
setMIFlags(unsigned Flags)250 const MachineInstrBuilder &setMIFlags(unsigned Flags) const {
251 MI->setFlags(Flags);
252 return *this;
253 }
254
setMIFlag(MachineInstr::MIFlag Flag)255 const MachineInstrBuilder &setMIFlag(MachineInstr::MIFlag Flag) const {
256 MI->setFlag(Flag);
257 return *this;
258 }
259
260 // Add a displacement from an existing MachineOperand with an added offset.
261 const MachineInstrBuilder &addDisp(const MachineOperand &Disp, int64_t off,
262 unsigned char TargetFlags = 0) const {
263 // If caller specifies new TargetFlags then use it, otherwise the
264 // default behavior is to copy the target flags from the existing
265 // MachineOperand. This means if the caller wants to clear the
266 // target flags it needs to do so explicitly.
267 if (0 == TargetFlags)
268 TargetFlags = Disp.getTargetFlags();
269
270 switch (Disp.getType()) {
271 default:
272 llvm_unreachable("Unhandled operand type in addDisp()");
273 case MachineOperand::MO_Immediate:
274 return addImm(Disp.getImm() + off);
275 case MachineOperand::MO_ConstantPoolIndex:
276 return addConstantPoolIndex(Disp.getIndex(), Disp.getOffset() + off,
277 TargetFlags);
278 case MachineOperand::MO_GlobalAddress:
279 return addGlobalAddress(Disp.getGlobal(), Disp.getOffset() + off,
280 TargetFlags);
281 }
282 }
283
284 /// Copy all the implicit operands from OtherMI onto this one.
285 const MachineInstrBuilder &
copyImplicitOps(const MachineInstr & OtherMI)286 copyImplicitOps(const MachineInstr &OtherMI) const {
287 MI->copyImplicitOps(*MF, OtherMI);
288 return *this;
289 }
290
constrainAllUses(const TargetInstrInfo & TII,const TargetRegisterInfo & TRI,const RegisterBankInfo & RBI)291 bool constrainAllUses(const TargetInstrInfo &TII,
292 const TargetRegisterInfo &TRI,
293 const RegisterBankInfo &RBI) const {
294 return constrainSelectedInstRegOperands(*MI, TII, TRI, RBI);
295 }
296 };
297
298 /// Builder interface. Specify how to create the initial instruction itself.
BuildMI(MachineFunction & MF,const DebugLoc & DL,const MCInstrDesc & MCID)299 inline MachineInstrBuilder BuildMI(MachineFunction &MF, const DebugLoc &DL,
300 const MCInstrDesc &MCID) {
301 return MachineInstrBuilder(MF, MF.CreateMachineInstr(MCID, DL));
302 }
303
304 /// This version of the builder sets up the first operand as a
305 /// destination virtual register.
BuildMI(MachineFunction & MF,const DebugLoc & DL,const MCInstrDesc & MCID,unsigned DestReg)306 inline MachineInstrBuilder BuildMI(MachineFunction &MF, const DebugLoc &DL,
307 const MCInstrDesc &MCID, unsigned DestReg) {
308 return MachineInstrBuilder(MF, MF.CreateMachineInstr(MCID, DL))
309 .addReg(DestReg, RegState::Define);
310 }
311
312 /// This version of the builder inserts the newly-built instruction before
313 /// the given position in the given MachineBasicBlock, and sets up the first
314 /// operand as a destination virtual register.
BuildMI(MachineBasicBlock & BB,MachineBasicBlock::iterator I,const DebugLoc & DL,const MCInstrDesc & MCID,unsigned DestReg)315 inline MachineInstrBuilder BuildMI(MachineBasicBlock &BB,
316 MachineBasicBlock::iterator I,
317 const DebugLoc &DL, const MCInstrDesc &MCID,
318 unsigned DestReg) {
319 MachineFunction &MF = *BB.getParent();
320 MachineInstr *MI = MF.CreateMachineInstr(MCID, DL);
321 BB.insert(I, MI);
322 return MachineInstrBuilder(MF, MI).addReg(DestReg, RegState::Define);
323 }
324
325 /// This version of the builder inserts the newly-built instruction before
326 /// the given position in the given MachineBasicBlock, and sets up the first
327 /// operand as a destination virtual register.
328 ///
329 /// If \c I is inside a bundle, then the newly inserted \a MachineInstr is
330 /// added to the same bundle.
BuildMI(MachineBasicBlock & BB,MachineBasicBlock::instr_iterator I,const DebugLoc & DL,const MCInstrDesc & MCID,unsigned DestReg)331 inline MachineInstrBuilder BuildMI(MachineBasicBlock &BB,
332 MachineBasicBlock::instr_iterator I,
333 const DebugLoc &DL, const MCInstrDesc &MCID,
334 unsigned DestReg) {
335 MachineFunction &MF = *BB.getParent();
336 MachineInstr *MI = MF.CreateMachineInstr(MCID, DL);
337 BB.insert(I, MI);
338 return MachineInstrBuilder(MF, MI).addReg(DestReg, RegState::Define);
339 }
340
BuildMI(MachineBasicBlock & BB,MachineInstr & I,const DebugLoc & DL,const MCInstrDesc & MCID,unsigned DestReg)341 inline MachineInstrBuilder BuildMI(MachineBasicBlock &BB, MachineInstr &I,
342 const DebugLoc &DL, const MCInstrDesc &MCID,
343 unsigned DestReg) {
344 // Calling the overload for instr_iterator is always correct. However, the
345 // definition is not available in headers, so inline the check.
346 if (I.isInsideBundle())
347 return BuildMI(BB, MachineBasicBlock::instr_iterator(I), DL, MCID, DestReg);
348 return BuildMI(BB, MachineBasicBlock::iterator(I), DL, MCID, DestReg);
349 }
350
BuildMI(MachineBasicBlock & BB,MachineInstr * I,const DebugLoc & DL,const MCInstrDesc & MCID,unsigned DestReg)351 inline MachineInstrBuilder BuildMI(MachineBasicBlock &BB, MachineInstr *I,
352 const DebugLoc &DL, const MCInstrDesc &MCID,
353 unsigned DestReg) {
354 return BuildMI(BB, *I, DL, MCID, DestReg);
355 }
356
357 /// This version of the builder inserts the newly-built instruction before the
358 /// given position in the given MachineBasicBlock, and does NOT take a
359 /// destination register.
BuildMI(MachineBasicBlock & BB,MachineBasicBlock::iterator I,const DebugLoc & DL,const MCInstrDesc & MCID)360 inline MachineInstrBuilder BuildMI(MachineBasicBlock &BB,
361 MachineBasicBlock::iterator I,
362 const DebugLoc &DL,
363 const MCInstrDesc &MCID) {
364 MachineFunction &MF = *BB.getParent();
365 MachineInstr *MI = MF.CreateMachineInstr(MCID, DL);
366 BB.insert(I, MI);
367 return MachineInstrBuilder(MF, MI);
368 }
369
BuildMI(MachineBasicBlock & BB,MachineBasicBlock::instr_iterator I,const DebugLoc & DL,const MCInstrDesc & MCID)370 inline MachineInstrBuilder BuildMI(MachineBasicBlock &BB,
371 MachineBasicBlock::instr_iterator I,
372 const DebugLoc &DL,
373 const MCInstrDesc &MCID) {
374 MachineFunction &MF = *BB.getParent();
375 MachineInstr *MI = MF.CreateMachineInstr(MCID, DL);
376 BB.insert(I, MI);
377 return MachineInstrBuilder(MF, MI);
378 }
379
BuildMI(MachineBasicBlock & BB,MachineInstr & I,const DebugLoc & DL,const MCInstrDesc & MCID)380 inline MachineInstrBuilder BuildMI(MachineBasicBlock &BB, MachineInstr &I,
381 const DebugLoc &DL,
382 const MCInstrDesc &MCID) {
383 // Calling the overload for instr_iterator is always correct. However, the
384 // definition is not available in headers, so inline the check.
385 if (I.isInsideBundle())
386 return BuildMI(BB, MachineBasicBlock::instr_iterator(I), DL, MCID);
387 return BuildMI(BB, MachineBasicBlock::iterator(I), DL, MCID);
388 }
389
BuildMI(MachineBasicBlock & BB,MachineInstr * I,const DebugLoc & DL,const MCInstrDesc & MCID)390 inline MachineInstrBuilder BuildMI(MachineBasicBlock &BB, MachineInstr *I,
391 const DebugLoc &DL,
392 const MCInstrDesc &MCID) {
393 return BuildMI(BB, *I, DL, MCID);
394 }
395
396 /// This version of the builder inserts the newly-built instruction at the end
397 /// of the given MachineBasicBlock, and does NOT take a destination register.
BuildMI(MachineBasicBlock * BB,const DebugLoc & DL,const MCInstrDesc & MCID)398 inline MachineInstrBuilder BuildMI(MachineBasicBlock *BB, const DebugLoc &DL,
399 const MCInstrDesc &MCID) {
400 return BuildMI(*BB, BB->end(), DL, MCID);
401 }
402
403 /// This version of the builder inserts the newly-built instruction at the
404 /// end of the given MachineBasicBlock, and sets up the first operand as a
405 /// destination virtual register.
BuildMI(MachineBasicBlock * BB,const DebugLoc & DL,const MCInstrDesc & MCID,unsigned DestReg)406 inline MachineInstrBuilder BuildMI(MachineBasicBlock *BB, const DebugLoc &DL,
407 const MCInstrDesc &MCID, unsigned DestReg) {
408 return BuildMI(*BB, BB->end(), DL, MCID, DestReg);
409 }
410
411 /// This version of the builder builds a DBG_VALUE intrinsic
412 /// for either a value in a register or a register-indirect
413 /// address. The convention is that a DBG_VALUE is indirect iff the
414 /// second operand is an immediate.
415 MachineInstrBuilder BuildMI(MachineFunction &MF, const DebugLoc &DL,
416 const MCInstrDesc &MCID, bool IsIndirect,
417 unsigned Reg, const MDNode *Variable,
418 const MDNode *Expr);
419
420 /// This version of the builder builds a DBG_VALUE intrinsic
421 /// for a MachineOperand.
422 MachineInstrBuilder BuildMI(MachineFunction &MF, const DebugLoc &DL,
423 const MCInstrDesc &MCID, bool IsIndirect,
424 MachineOperand &MO, const MDNode *Variable,
425 const MDNode *Expr);
426
427 /// This version of the builder builds a DBG_VALUE intrinsic
428 /// for either a value in a register or a register-indirect
429 /// address and inserts it at position I.
430 MachineInstrBuilder BuildMI(MachineBasicBlock &BB,
431 MachineBasicBlock::iterator I, const DebugLoc &DL,
432 const MCInstrDesc &MCID, bool IsIndirect,
433 unsigned Reg, const MDNode *Variable,
434 const MDNode *Expr);
435
436 /// This version of the builder builds a DBG_VALUE intrinsic
437 /// for a machine operand and inserts it at position I.
438 MachineInstrBuilder BuildMI(MachineBasicBlock &BB,
439 MachineBasicBlock::iterator I, const DebugLoc &DL,
440 const MCInstrDesc &MCID, bool IsIndirect,
441 MachineOperand &MO, const MDNode *Variable,
442 const MDNode *Expr);
443
444 /// Clone a DBG_VALUE whose value has been spilled to FrameIndex.
445 MachineInstr *buildDbgValueForSpill(MachineBasicBlock &BB,
446 MachineBasicBlock::iterator I,
447 const MachineInstr &Orig, int FrameIndex);
448
449 /// Update a DBG_VALUE whose value has been spilled to FrameIndex. Useful when
450 /// modifying an instruction in place while iterating over a basic block.
451 void updateDbgValueForSpill(MachineInstr &Orig, int FrameIndex);
452
getDefRegState(bool B)453 inline unsigned getDefRegState(bool B) {
454 return B ? RegState::Define : 0;
455 }
getImplRegState(bool B)456 inline unsigned getImplRegState(bool B) {
457 return B ? RegState::Implicit : 0;
458 }
getKillRegState(bool B)459 inline unsigned getKillRegState(bool B) {
460 return B ? RegState::Kill : 0;
461 }
getDeadRegState(bool B)462 inline unsigned getDeadRegState(bool B) {
463 return B ? RegState::Dead : 0;
464 }
getUndefRegState(bool B)465 inline unsigned getUndefRegState(bool B) {
466 return B ? RegState::Undef : 0;
467 }
getInternalReadRegState(bool B)468 inline unsigned getInternalReadRegState(bool B) {
469 return B ? RegState::InternalRead : 0;
470 }
getDebugRegState(bool B)471 inline unsigned getDebugRegState(bool B) {
472 return B ? RegState::Debug : 0;
473 }
getRenamableRegState(bool B)474 inline unsigned getRenamableRegState(bool B) {
475 return B ? RegState::Renamable : 0;
476 }
477
478 /// Get all register state flags from machine operand \p RegOp.
getRegState(const MachineOperand & RegOp)479 inline unsigned getRegState(const MachineOperand &RegOp) {
480 assert(RegOp.isReg() && "Not a register operand");
481 return getDefRegState(RegOp.isDef()) |
482 getImplRegState(RegOp.isImplicit()) |
483 getKillRegState(RegOp.isKill()) |
484 getDeadRegState(RegOp.isDead()) |
485 getUndefRegState(RegOp.isUndef()) |
486 getInternalReadRegState(RegOp.isInternalRead()) |
487 getDebugRegState(RegOp.isDebug()) |
488 getRenamableRegState(
489 TargetRegisterInfo::isPhysicalRegister(RegOp.getReg()) &&
490 RegOp.isRenamable());
491 }
492
493 /// Helper class for constructing bundles of MachineInstrs.
494 ///
495 /// MIBundleBuilder can create a bundle from scratch by inserting new
496 /// MachineInstrs one at a time, or it can create a bundle from a sequence of
497 /// existing MachineInstrs in a basic block.
498 class MIBundleBuilder {
499 MachineBasicBlock &MBB;
500 MachineBasicBlock::instr_iterator Begin;
501 MachineBasicBlock::instr_iterator End;
502
503 public:
504 /// Create an MIBundleBuilder that inserts instructions into a new bundle in
505 /// BB above the bundle or instruction at Pos.
MIBundleBuilder(MachineBasicBlock & BB,MachineBasicBlock::iterator Pos)506 MIBundleBuilder(MachineBasicBlock &BB, MachineBasicBlock::iterator Pos)
507 : MBB(BB), Begin(Pos.getInstrIterator()), End(Begin) {}
508
509 /// Create a bundle from the sequence of instructions between B and E.
MIBundleBuilder(MachineBasicBlock & BB,MachineBasicBlock::iterator B,MachineBasicBlock::iterator E)510 MIBundleBuilder(MachineBasicBlock &BB, MachineBasicBlock::iterator B,
511 MachineBasicBlock::iterator E)
512 : MBB(BB), Begin(B.getInstrIterator()), End(E.getInstrIterator()) {
513 assert(B != E && "No instructions to bundle");
514 ++B;
515 while (B != E) {
516 MachineInstr &MI = *B;
517 ++B;
518 MI.bundleWithPred();
519 }
520 }
521
522 /// Create an MIBundleBuilder representing an existing instruction or bundle
523 /// that has MI as its head.
MIBundleBuilder(MachineInstr * MI)524 explicit MIBundleBuilder(MachineInstr *MI)
525 : MBB(*MI->getParent()), Begin(MI),
526 End(getBundleEnd(MI->getIterator())) {}
527
528 /// Return a reference to the basic block containing this bundle.
getMBB()529 MachineBasicBlock &getMBB() const { return MBB; }
530
531 /// Return true if no instructions have been inserted in this bundle yet.
532 /// Empty bundles aren't representable in a MachineBasicBlock.
empty()533 bool empty() const { return Begin == End; }
534
535 /// Return an iterator to the first bundled instruction.
begin()536 MachineBasicBlock::instr_iterator begin() const { return Begin; }
537
538 /// Return an iterator beyond the last bundled instruction.
end()539 MachineBasicBlock::instr_iterator end() const { return End; }
540
541 /// Insert MI into this bundle before I which must point to an instruction in
542 /// the bundle, or end().
insert(MachineBasicBlock::instr_iterator I,MachineInstr * MI)543 MIBundleBuilder &insert(MachineBasicBlock::instr_iterator I,
544 MachineInstr *MI) {
545 MBB.insert(I, MI);
546 if (I == Begin) {
547 if (!empty())
548 MI->bundleWithSucc();
549 Begin = MI->getIterator();
550 return *this;
551 }
552 if (I == End) {
553 MI->bundleWithPred();
554 return *this;
555 }
556 // MI was inserted in the middle of the bundle, so its neighbors' flags are
557 // already fine. Update MI's bundle flags manually.
558 MI->setFlag(MachineInstr::BundledPred);
559 MI->setFlag(MachineInstr::BundledSucc);
560 return *this;
561 }
562
563 /// Insert MI into MBB by prepending it to the instructions in the bundle.
564 /// MI will become the first instruction in the bundle.
prepend(MachineInstr * MI)565 MIBundleBuilder &prepend(MachineInstr *MI) {
566 return insert(begin(), MI);
567 }
568
569 /// Insert MI into MBB by appending it to the instructions in the bundle.
570 /// MI will become the last instruction in the bundle.
append(MachineInstr * MI)571 MIBundleBuilder &append(MachineInstr *MI) {
572 return insert(end(), MI);
573 }
574 };
575
576 } // end namespace llvm
577
578 #endif // LLVM_CODEGEN_MACHINEINSTRBUILDER_H
579