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1 //===-- CodeGen/MachineInstBuilder.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(X86::ADDrr8, 2).addReg(argVal1).addReg(argVal2);
14 //
15 //===----------------------------------------------------------------------===//
16 
17 #ifndef LLVM_CODEGEN_MACHINEINSTRBUILDER_H
18 #define LLVM_CODEGEN_MACHINEINSTRBUILDER_H
19 
20 #include "llvm/CodeGen/MachineFunction.h"
21 #include "llvm/CodeGen/MachineInstrBundle.h"
22 #include "llvm/Support/ErrorHandling.h"
23 
24 namespace llvm {
25 
26 class MCInstrDesc;
27 class MDNode;
28 
29 namespace RegState {
30   enum {
31     Define         = 0x2,
32     Implicit       = 0x4,
33     Kill           = 0x8,
34     Dead           = 0x10,
35     Undef          = 0x20,
36     EarlyClobber   = 0x40,
37     Debug          = 0x80,
38     InternalRead   = 0x100,
39     DefineNoRead   = Define | Undef,
40     ImplicitDefine = Implicit | Define,
41     ImplicitKill   = Implicit | Kill
42   };
43 }
44 
45 class MachineInstrBuilder {
46   MachineFunction *MF;
47   MachineInstr *MI;
48 public:
MachineInstrBuilder()49   MachineInstrBuilder() : MF(0), MI(0) {}
50 
51   /// Create a MachineInstrBuilder for manipulating an existing instruction.
52   /// F must be the machine function  that was used to allocate I.
MachineInstrBuilder(MachineFunction & F,MachineInstr * I)53   MachineInstrBuilder(MachineFunction &F, MachineInstr *I) : MF(&F), MI(I) {}
54 
55   /// Allow automatic conversion to the machine instruction we are working on.
56   ///
57   operator MachineInstr*() const { return MI; }
58   MachineInstr *operator->() const { return MI; }
iterator()59   operator MachineBasicBlock::iterator() const { return MI; }
60 
61   /// addReg - Add a new virtual register operand...
62   ///
63   const
64   MachineInstrBuilder &addReg(unsigned RegNo, unsigned flags = 0,
65                               unsigned SubReg = 0) const {
66     assert((flags & 0x1) == 0 &&
67            "Passing in 'true' to addReg is forbidden! Use enums instead.");
68     MI->addOperand(*MF, MachineOperand::CreateReg(RegNo,
69                                                flags & RegState::Define,
70                                                flags & RegState::Implicit,
71                                                flags & RegState::Kill,
72                                                flags & RegState::Dead,
73                                                flags & RegState::Undef,
74                                                flags & RegState::EarlyClobber,
75                                                SubReg,
76                                                flags & RegState::Debug,
77                                                flags & RegState::InternalRead));
78     return *this;
79   }
80 
81   /// addImm - Add a new immediate operand.
82   ///
addImm(int64_t Val)83   const MachineInstrBuilder &addImm(int64_t Val) const {
84     MI->addOperand(*MF, MachineOperand::CreateImm(Val));
85     return *this;
86   }
87 
addCImm(const ConstantInt * Val)88   const MachineInstrBuilder &addCImm(const ConstantInt *Val) const {
89     MI->addOperand(*MF, MachineOperand::CreateCImm(Val));
90     return *this;
91   }
92 
addFPImm(const ConstantFP * Val)93   const MachineInstrBuilder &addFPImm(const ConstantFP *Val) const {
94     MI->addOperand(*MF, MachineOperand::CreateFPImm(Val));
95     return *this;
96   }
97 
98   const MachineInstrBuilder &addMBB(MachineBasicBlock *MBB,
99                                     unsigned char TargetFlags = 0) const {
100     MI->addOperand(*MF, MachineOperand::CreateMBB(MBB, TargetFlags));
101     return *this;
102   }
103 
addFrameIndex(int Idx)104   const MachineInstrBuilder &addFrameIndex(int Idx) const {
105     MI->addOperand(*MF, MachineOperand::CreateFI(Idx));
106     return *this;
107   }
108 
109   const MachineInstrBuilder &addConstantPoolIndex(unsigned Idx,
110                                                   int Offset = 0,
111                                           unsigned char TargetFlags = 0) const {
112     MI->addOperand(*MF, MachineOperand::CreateCPI(Idx, Offset, TargetFlags));
113     return *this;
114   }
115 
116   const MachineInstrBuilder &addTargetIndex(unsigned Idx, int64_t Offset = 0,
117                                           unsigned char TargetFlags = 0) const {
118     MI->addOperand(*MF, MachineOperand::CreateTargetIndex(Idx, Offset,
119                                                           TargetFlags));
120     return *this;
121   }
122 
123   const MachineInstrBuilder &addJumpTableIndex(unsigned Idx,
124                                           unsigned char TargetFlags = 0) const {
125     MI->addOperand(*MF, MachineOperand::CreateJTI(Idx, TargetFlags));
126     return *this;
127   }
128 
129   const MachineInstrBuilder &addGlobalAddress(const GlobalValue *GV,
130                                               int64_t Offset = 0,
131                                           unsigned char TargetFlags = 0) const {
132     MI->addOperand(*MF, MachineOperand::CreateGA(GV, Offset, TargetFlags));
133     return *this;
134   }
135 
136   const MachineInstrBuilder &addExternalSymbol(const char *FnName,
137                                           unsigned char TargetFlags = 0) const {
138     MI->addOperand(*MF, MachineOperand::CreateES(FnName, TargetFlags));
139     return *this;
140   }
141 
142   const MachineInstrBuilder &addBlockAddress(const BlockAddress *BA,
143                                              int64_t Offset = 0,
144                                           unsigned char TargetFlags = 0) const {
145     MI->addOperand(*MF, MachineOperand::CreateBA(BA, Offset, TargetFlags));
146     return *this;
147   }
148 
addRegMask(const uint32_t * Mask)149   const MachineInstrBuilder &addRegMask(const uint32_t *Mask) const {
150     MI->addOperand(*MF, MachineOperand::CreateRegMask(Mask));
151     return *this;
152   }
153 
addMemOperand(MachineMemOperand * MMO)154   const MachineInstrBuilder &addMemOperand(MachineMemOperand *MMO) const {
155     MI->addMemOperand(*MF, MMO);
156     return *this;
157   }
158 
setMemRefs(MachineInstr::mmo_iterator b,MachineInstr::mmo_iterator e)159   const MachineInstrBuilder &setMemRefs(MachineInstr::mmo_iterator b,
160                                         MachineInstr::mmo_iterator e) const {
161     MI->setMemRefs(b, e);
162     return *this;
163   }
164 
165 
addOperand(const MachineOperand & MO)166   const MachineInstrBuilder &addOperand(const MachineOperand &MO) const {
167     MI->addOperand(*MF, MO);
168     return *this;
169   }
170 
addMetadata(const MDNode * MD)171   const MachineInstrBuilder &addMetadata(const MDNode *MD) const {
172     MI->addOperand(*MF, MachineOperand::CreateMetadata(MD));
173     return *this;
174   }
175 
addSym(MCSymbol * Sym)176   const MachineInstrBuilder &addSym(MCSymbol *Sym) const {
177     MI->addOperand(*MF, MachineOperand::CreateMCSymbol(Sym));
178     return *this;
179   }
180 
setMIFlags(unsigned Flags)181   const MachineInstrBuilder &setMIFlags(unsigned Flags) const {
182     MI->setFlags(Flags);
183     return *this;
184   }
185 
setMIFlag(MachineInstr::MIFlag Flag)186   const MachineInstrBuilder &setMIFlag(MachineInstr::MIFlag Flag) const {
187     MI->setFlag(Flag);
188     return *this;
189   }
190 
191   // Add a displacement from an existing MachineOperand with an added offset.
192   const MachineInstrBuilder &addDisp(const MachineOperand &Disp, int64_t off,
193                                      unsigned char TargetFlags = 0) const {
194     switch (Disp.getType()) {
195       default:
196         llvm_unreachable("Unhandled operand type in addDisp()");
197       case MachineOperand::MO_Immediate:
198         return addImm(Disp.getImm() + off);
199       case MachineOperand::MO_GlobalAddress: {
200         // If caller specifies new TargetFlags then use it, otherwise the
201         // default behavior is to copy the target flags from the existing
202         // MachineOperand. This means if the caller wants to clear the
203         // target flags it needs to do so explicitly.
204         if (TargetFlags)
205           return addGlobalAddress(Disp.getGlobal(), Disp.getOffset() + off,
206                                   TargetFlags);
207         return addGlobalAddress(Disp.getGlobal(), Disp.getOffset() + off,
208                                 Disp.getTargetFlags());
209       }
210     }
211   }
212 
213   /// Copy all the implicit operands from OtherMI onto this one.
copyImplicitOps(const MachineInstr * OtherMI)214   const MachineInstrBuilder &copyImplicitOps(const MachineInstr *OtherMI) {
215     MI->copyImplicitOps(*MF, OtherMI);
216     return *this;
217   }
218 };
219 
220 /// BuildMI - Builder interface.  Specify how to create the initial instruction
221 /// itself.
222 ///
BuildMI(MachineFunction & MF,DebugLoc DL,const MCInstrDesc & MCID)223 inline MachineInstrBuilder BuildMI(MachineFunction &MF,
224                                    DebugLoc DL,
225                                    const MCInstrDesc &MCID) {
226   return MachineInstrBuilder(MF, MF.CreateMachineInstr(MCID, DL));
227 }
228 
229 /// BuildMI - This version of the builder sets up the first operand as a
230 /// destination virtual register.
231 ///
BuildMI(MachineFunction & MF,DebugLoc DL,const MCInstrDesc & MCID,unsigned DestReg)232 inline MachineInstrBuilder BuildMI(MachineFunction &MF,
233                                    DebugLoc DL,
234                                    const MCInstrDesc &MCID,
235                                    unsigned DestReg) {
236   return MachineInstrBuilder(MF, MF.CreateMachineInstr(MCID, DL))
237            .addReg(DestReg, RegState::Define);
238 }
239 
240 /// BuildMI - This version of the builder inserts the newly-built
241 /// instruction before the given position in the given MachineBasicBlock, and
242 /// sets up the first operand as a destination virtual register.
243 ///
BuildMI(MachineBasicBlock & BB,MachineBasicBlock::iterator I,DebugLoc DL,const MCInstrDesc & MCID,unsigned DestReg)244 inline MachineInstrBuilder BuildMI(MachineBasicBlock &BB,
245                                    MachineBasicBlock::iterator I,
246                                    DebugLoc DL,
247                                    const MCInstrDesc &MCID,
248                                    unsigned DestReg) {
249   MachineFunction &MF = *BB.getParent();
250   MachineInstr *MI = MF.CreateMachineInstr(MCID, DL);
251   BB.insert(I, MI);
252   return MachineInstrBuilder(MF, MI).addReg(DestReg, RegState::Define);
253 }
254 
BuildMI(MachineBasicBlock & BB,MachineBasicBlock::instr_iterator I,DebugLoc DL,const MCInstrDesc & MCID,unsigned DestReg)255 inline MachineInstrBuilder BuildMI(MachineBasicBlock &BB,
256                                    MachineBasicBlock::instr_iterator I,
257                                    DebugLoc DL,
258                                    const MCInstrDesc &MCID,
259                                    unsigned DestReg) {
260   MachineFunction &MF = *BB.getParent();
261   MachineInstr *MI = MF.CreateMachineInstr(MCID, DL);
262   BB.insert(I, MI);
263   return MachineInstrBuilder(MF, MI).addReg(DestReg, RegState::Define);
264 }
265 
BuildMI(MachineBasicBlock & BB,MachineInstr * I,DebugLoc DL,const MCInstrDesc & MCID,unsigned DestReg)266 inline MachineInstrBuilder BuildMI(MachineBasicBlock &BB,
267                                    MachineInstr *I,
268                                    DebugLoc DL,
269                                    const MCInstrDesc &MCID,
270                                    unsigned DestReg) {
271   if (I->isInsideBundle()) {
272     MachineBasicBlock::instr_iterator MII = I;
273     return BuildMI(BB, MII, DL, MCID, DestReg);
274   }
275 
276   MachineBasicBlock::iterator MII = I;
277   return BuildMI(BB, MII, DL, MCID, DestReg);
278 }
279 
280 /// BuildMI - This version of the builder inserts the newly-built
281 /// instruction before the given position in the given MachineBasicBlock, and
282 /// does NOT take a destination register.
283 ///
BuildMI(MachineBasicBlock & BB,MachineBasicBlock::iterator I,DebugLoc DL,const MCInstrDesc & MCID)284 inline MachineInstrBuilder BuildMI(MachineBasicBlock &BB,
285                                    MachineBasicBlock::iterator I,
286                                    DebugLoc DL,
287                                    const MCInstrDesc &MCID) {
288   MachineFunction &MF = *BB.getParent();
289   MachineInstr *MI = MF.CreateMachineInstr(MCID, DL);
290   BB.insert(I, MI);
291   return MachineInstrBuilder(MF, MI);
292 }
293 
BuildMI(MachineBasicBlock & BB,MachineBasicBlock::instr_iterator I,DebugLoc DL,const MCInstrDesc & MCID)294 inline MachineInstrBuilder BuildMI(MachineBasicBlock &BB,
295                                    MachineBasicBlock::instr_iterator I,
296                                    DebugLoc DL,
297                                    const MCInstrDesc &MCID) {
298   MachineFunction &MF = *BB.getParent();
299   MachineInstr *MI = MF.CreateMachineInstr(MCID, DL);
300   BB.insert(I, MI);
301   return MachineInstrBuilder(MF, MI);
302 }
303 
BuildMI(MachineBasicBlock & BB,MachineInstr * I,DebugLoc DL,const MCInstrDesc & MCID)304 inline MachineInstrBuilder BuildMI(MachineBasicBlock &BB,
305                                    MachineInstr *I,
306                                    DebugLoc DL,
307                                    const MCInstrDesc &MCID) {
308   if (I->isInsideBundle()) {
309     MachineBasicBlock::instr_iterator MII = I;
310     return BuildMI(BB, MII, DL, MCID);
311   }
312 
313   MachineBasicBlock::iterator MII = I;
314   return BuildMI(BB, MII, DL, MCID);
315 }
316 
317 /// BuildMI - This version of the builder inserts the newly-built
318 /// instruction at the end of the given MachineBasicBlock, and does NOT take a
319 /// destination register.
320 ///
BuildMI(MachineBasicBlock * BB,DebugLoc DL,const MCInstrDesc & MCID)321 inline MachineInstrBuilder BuildMI(MachineBasicBlock *BB,
322                                    DebugLoc DL,
323                                    const MCInstrDesc &MCID) {
324   return BuildMI(*BB, BB->end(), DL, MCID);
325 }
326 
327 /// BuildMI - This version of the builder inserts the newly-built
328 /// instruction at the end of the given MachineBasicBlock, and sets up the first
329 /// operand as a destination virtual register.
330 ///
BuildMI(MachineBasicBlock * BB,DebugLoc DL,const MCInstrDesc & MCID,unsigned DestReg)331 inline MachineInstrBuilder BuildMI(MachineBasicBlock *BB,
332                                    DebugLoc DL,
333                                    const MCInstrDesc &MCID,
334                                    unsigned DestReg) {
335   return BuildMI(*BB, BB->end(), DL, MCID, DestReg);
336 }
337 
338 /// BuildMI - This version of the builder builds a DBG_VALUE intrinsic
339 /// for either a value in a register or a register-indirect+offset
340 /// address.  The convention is that a DBG_VALUE is indirect iff the
341 /// second operand is an immediate.
342 ///
BuildMI(MachineFunction & MF,DebugLoc DL,const MCInstrDesc & MCID,bool IsIndirect,unsigned Reg,unsigned Offset,const MDNode * MD)343 inline MachineInstrBuilder BuildMI(MachineFunction &MF,
344                                    DebugLoc DL,
345                                    const MCInstrDesc &MCID,
346                                    bool IsIndirect,
347                                    unsigned Reg,
348                                    unsigned Offset,
349                                    const MDNode *MD) {
350   if (IsIndirect)
351     return BuildMI(MF, DL, MCID)
352       .addReg(Reg, RegState::Debug)
353       .addImm(Offset)
354       .addMetadata(MD);
355   else {
356     assert(Offset == 0 && "A direct address cannot have an offset.");
357     return BuildMI(MF, DL, MCID)
358       .addReg(Reg, RegState::Debug)
359       .addReg(0U, RegState::Debug)
360       .addMetadata(MD);
361   }
362 }
363 
364 /// BuildMI - This version of the builder builds a DBG_VALUE intrinsic
365 /// for either a value in a register or a register-indirect+offset
366 /// address and inserts it at position I.
367 ///
BuildMI(MachineBasicBlock & BB,MachineBasicBlock::iterator I,DebugLoc DL,const MCInstrDesc & MCID,bool IsIndirect,unsigned Reg,unsigned Offset,const MDNode * MD)368 inline MachineInstrBuilder BuildMI(MachineBasicBlock &BB,
369                                    MachineBasicBlock::iterator I,
370                                    DebugLoc DL,
371                                    const MCInstrDesc &MCID,
372                                    bool IsIndirect,
373                                    unsigned Reg,
374                                    unsigned Offset,
375                                    const MDNode *MD) {
376   MachineFunction &MF = *BB.getParent();
377   MachineInstr *MI = BuildMI(MF, DL, MCID, IsIndirect, Reg, Offset, MD);
378   BB.insert(I, MI);
379   return MachineInstrBuilder(MF, MI);
380 }
381 
382 
getDefRegState(bool B)383 inline unsigned getDefRegState(bool B) {
384   return B ? RegState::Define : 0;
385 }
getImplRegState(bool B)386 inline unsigned getImplRegState(bool B) {
387   return B ? RegState::Implicit : 0;
388 }
getKillRegState(bool B)389 inline unsigned getKillRegState(bool B) {
390   return B ? RegState::Kill : 0;
391 }
getDeadRegState(bool B)392 inline unsigned getDeadRegState(bool B) {
393   return B ? RegState::Dead : 0;
394 }
getUndefRegState(bool B)395 inline unsigned getUndefRegState(bool B) {
396   return B ? RegState::Undef : 0;
397 }
getInternalReadRegState(bool B)398 inline unsigned getInternalReadRegState(bool B) {
399   return B ? RegState::InternalRead : 0;
400 }
getDebugRegState(bool B)401 inline unsigned getDebugRegState(bool B) {
402   return B ? RegState::Debug : 0;
403 }
404 
405 
406 /// Helper class for constructing bundles of MachineInstrs.
407 ///
408 /// MIBundleBuilder can create a bundle from scratch by inserting new
409 /// MachineInstrs one at a time, or it can create a bundle from a sequence of
410 /// existing MachineInstrs in a basic block.
411 class MIBundleBuilder {
412   MachineBasicBlock &MBB;
413   MachineBasicBlock::instr_iterator Begin;
414   MachineBasicBlock::instr_iterator End;
415 
416 public:
417   /// Create an MIBundleBuilder that inserts instructions into a new bundle in
418   /// BB above the bundle or instruction at Pos.
MIBundleBuilder(MachineBasicBlock & BB,MachineBasicBlock::iterator Pos)419   MIBundleBuilder(MachineBasicBlock &BB,
420                   MachineBasicBlock::iterator Pos)
421     : MBB(BB), Begin(Pos.getInstrIterator()), End(Begin) {}
422 
423   /// Create a bundle from the sequence of instructions between B and E.
MIBundleBuilder(MachineBasicBlock & BB,MachineBasicBlock::iterator B,MachineBasicBlock::iterator E)424   MIBundleBuilder(MachineBasicBlock &BB,
425                   MachineBasicBlock::iterator B,
426                   MachineBasicBlock::iterator E)
427     : MBB(BB), Begin(B.getInstrIterator()), End(E.getInstrIterator()) {
428     assert(B != E && "No instructions to bundle");
429     ++B;
430     while (B != E) {
431       MachineInstr *MI = B;
432       ++B;
433       MI->bundleWithPred();
434     }
435   }
436 
437   /// Create an MIBundleBuilder representing an existing instruction or bundle
438   /// that has MI as its head.
MIBundleBuilder(MachineInstr * MI)439   explicit MIBundleBuilder(MachineInstr *MI)
440     : MBB(*MI->getParent()), Begin(MI), End(getBundleEnd(MI)) {}
441 
442   /// Return a reference to the basic block containing this bundle.
getMBB()443   MachineBasicBlock &getMBB() const { return MBB; }
444 
445   /// Return true if no instructions have been inserted in this bundle yet.
446   /// Empty bundles aren't representable in a MachineBasicBlock.
empty()447   bool empty() const { return Begin == End; }
448 
449   /// Return an iterator to the first bundled instruction.
begin()450   MachineBasicBlock::instr_iterator begin() const { return Begin; }
451 
452   /// Return an iterator beyond the last bundled instruction.
end()453   MachineBasicBlock::instr_iterator end() const { return End; }
454 
455   /// Insert MI into this bundle before I which must point to an instruction in
456   /// the bundle, or end().
insert(MachineBasicBlock::instr_iterator I,MachineInstr * MI)457   MIBundleBuilder &insert(MachineBasicBlock::instr_iterator I,
458                           MachineInstr *MI) {
459     MBB.insert(I, MI);
460     if (I == Begin) {
461       if (!empty())
462         MI->bundleWithSucc();
463       Begin = MI;
464       return *this;
465     }
466     if (I == End) {
467       MI->bundleWithPred();
468       return *this;
469     }
470     // MI was inserted in the middle of the bundle, so its neighbors' flags are
471     // already fine. Update MI's bundle flags manually.
472     MI->setFlag(MachineInstr::BundledPred);
473     MI->setFlag(MachineInstr::BundledSucc);
474     return *this;
475   }
476 
477   /// Insert MI into MBB by prepending it to the instructions in the bundle.
478   /// MI will become the first instruction in the bundle.
prepend(MachineInstr * MI)479   MIBundleBuilder &prepend(MachineInstr *MI) {
480     return insert(begin(), MI);
481   }
482 
483   /// Insert MI into MBB by appending it to the instructions in the bundle.
484   /// MI will become the last instruction in the bundle.
append(MachineInstr * MI)485   MIBundleBuilder &append(MachineInstr *MI) {
486     return insert(end(), MI);
487   }
488 };
489 
490 } // End llvm namespace
491 
492 #endif
493