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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(nullptr), MI(nullptr) {}
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   /// If conversion operators fail, use this method to get the MachineInstr
62   /// explicitly.
getInstr()63   MachineInstr *getInstr() const { return MI; }
64 
65   /// addReg - Add a new virtual register operand...
66   ///
67   const
68   MachineInstrBuilder &addReg(unsigned RegNo, unsigned flags = 0,
69                               unsigned SubReg = 0) const {
70     assert((flags & 0x1) == 0 &&
71            "Passing in 'true' to addReg is forbidden! Use enums instead.");
72     MI->addOperand(*MF, MachineOperand::CreateReg(RegNo,
73                                                flags & RegState::Define,
74                                                flags & RegState::Implicit,
75                                                flags & RegState::Kill,
76                                                flags & RegState::Dead,
77                                                flags & RegState::Undef,
78                                                flags & RegState::EarlyClobber,
79                                                SubReg,
80                                                flags & RegState::Debug,
81                                                flags & RegState::InternalRead));
82     return *this;
83   }
84 
85   /// addImm - Add a new immediate operand.
86   ///
addImm(int64_t Val)87   const MachineInstrBuilder &addImm(int64_t Val) const {
88     MI->addOperand(*MF, MachineOperand::CreateImm(Val));
89     return *this;
90   }
91 
addCImm(const ConstantInt * Val)92   const MachineInstrBuilder &addCImm(const ConstantInt *Val) const {
93     MI->addOperand(*MF, MachineOperand::CreateCImm(Val));
94     return *this;
95   }
96 
addFPImm(const ConstantFP * Val)97   const MachineInstrBuilder &addFPImm(const ConstantFP *Val) const {
98     MI->addOperand(*MF, MachineOperand::CreateFPImm(Val));
99     return *this;
100   }
101 
102   const MachineInstrBuilder &addMBB(MachineBasicBlock *MBB,
103                                     unsigned char TargetFlags = 0) const {
104     MI->addOperand(*MF, MachineOperand::CreateMBB(MBB, TargetFlags));
105     return *this;
106   }
107 
addFrameIndex(int Idx)108   const MachineInstrBuilder &addFrameIndex(int Idx) const {
109     MI->addOperand(*MF, MachineOperand::CreateFI(Idx));
110     return *this;
111   }
112 
113   const MachineInstrBuilder &addConstantPoolIndex(unsigned Idx,
114                                                   int Offset = 0,
115                                           unsigned char TargetFlags = 0) const {
116     MI->addOperand(*MF, MachineOperand::CreateCPI(Idx, Offset, TargetFlags));
117     return *this;
118   }
119 
120   const MachineInstrBuilder &addTargetIndex(unsigned Idx, int64_t Offset = 0,
121                                           unsigned char TargetFlags = 0) const {
122     MI->addOperand(*MF, MachineOperand::CreateTargetIndex(Idx, Offset,
123                                                           TargetFlags));
124     return *this;
125   }
126 
127   const MachineInstrBuilder &addJumpTableIndex(unsigned Idx,
128                                           unsigned char TargetFlags = 0) const {
129     MI->addOperand(*MF, MachineOperand::CreateJTI(Idx, TargetFlags));
130     return *this;
131   }
132 
133   const MachineInstrBuilder &addGlobalAddress(const GlobalValue *GV,
134                                               int64_t Offset = 0,
135                                           unsigned char TargetFlags = 0) const {
136     MI->addOperand(*MF, MachineOperand::CreateGA(GV, Offset, TargetFlags));
137     return *this;
138   }
139 
140   const MachineInstrBuilder &addExternalSymbol(const char *FnName,
141                                           unsigned char TargetFlags = 0) const {
142     MI->addOperand(*MF, MachineOperand::CreateES(FnName, TargetFlags));
143     return *this;
144   }
145 
146   const MachineInstrBuilder &addBlockAddress(const BlockAddress *BA,
147                                              int64_t Offset = 0,
148                                           unsigned char TargetFlags = 0) const {
149     MI->addOperand(*MF, MachineOperand::CreateBA(BA, Offset, TargetFlags));
150     return *this;
151   }
152 
addRegMask(const uint32_t * Mask)153   const MachineInstrBuilder &addRegMask(const uint32_t *Mask) const {
154     MI->addOperand(*MF, MachineOperand::CreateRegMask(Mask));
155     return *this;
156   }
157 
addMemOperand(MachineMemOperand * MMO)158   const MachineInstrBuilder &addMemOperand(MachineMemOperand *MMO) const {
159     MI->addMemOperand(*MF, MMO);
160     return *this;
161   }
162 
setMemRefs(MachineInstr::mmo_iterator b,MachineInstr::mmo_iterator e)163   const MachineInstrBuilder &setMemRefs(MachineInstr::mmo_iterator b,
164                                         MachineInstr::mmo_iterator e) const {
165     MI->setMemRefs(b, e);
166     return *this;
167   }
168 
169 
addOperand(const MachineOperand & MO)170   const MachineInstrBuilder &addOperand(const MachineOperand &MO) const {
171     MI->addOperand(*MF, MO);
172     return *this;
173   }
174 
addMetadata(const MDNode * MD)175   const MachineInstrBuilder &addMetadata(const MDNode *MD) const {
176     MI->addOperand(*MF, MachineOperand::CreateMetadata(MD));
177     assert((MI->isDebugValue() ? static_cast<bool>(MI->getDebugVariable())
178                                : true) &&
179            "first MDNode argument of a DBG_VALUE not a DIVariable");
180     return *this;
181   }
182 
addCFIIndex(unsigned CFIIndex)183   const MachineInstrBuilder &addCFIIndex(unsigned CFIIndex) const {
184     MI->addOperand(*MF, MachineOperand::CreateCFIIndex(CFIIndex));
185     return *this;
186   }
187 
addSym(MCSymbol * Sym)188   const MachineInstrBuilder &addSym(MCSymbol *Sym) const {
189     MI->addOperand(*MF, MachineOperand::CreateMCSymbol(Sym));
190     return *this;
191   }
192 
setMIFlags(unsigned Flags)193   const MachineInstrBuilder &setMIFlags(unsigned Flags) const {
194     MI->setFlags(Flags);
195     return *this;
196   }
197 
setMIFlag(MachineInstr::MIFlag Flag)198   const MachineInstrBuilder &setMIFlag(MachineInstr::MIFlag Flag) const {
199     MI->setFlag(Flag);
200     return *this;
201   }
202 
203   // Add a displacement from an existing MachineOperand with an added offset.
204   const MachineInstrBuilder &addDisp(const MachineOperand &Disp, int64_t off,
205                                      unsigned char TargetFlags = 0) const {
206     switch (Disp.getType()) {
207       default:
208         llvm_unreachable("Unhandled operand type in addDisp()");
209       case MachineOperand::MO_Immediate:
210         return addImm(Disp.getImm() + off);
211       case MachineOperand::MO_GlobalAddress: {
212         // If caller specifies new TargetFlags then use it, otherwise the
213         // default behavior is to copy the target flags from the existing
214         // MachineOperand. This means if the caller wants to clear the
215         // target flags it needs to do so explicitly.
216         if (TargetFlags)
217           return addGlobalAddress(Disp.getGlobal(), Disp.getOffset() + off,
218                                   TargetFlags);
219         return addGlobalAddress(Disp.getGlobal(), Disp.getOffset() + off,
220                                 Disp.getTargetFlags());
221       }
222     }
223   }
224 
225   /// Copy all the implicit operands from OtherMI onto this one.
copyImplicitOps(const MachineInstr * OtherMI)226   const MachineInstrBuilder &copyImplicitOps(const MachineInstr *OtherMI) {
227     MI->copyImplicitOps(*MF, OtherMI);
228     return *this;
229   }
230 };
231 
232 /// BuildMI - Builder interface.  Specify how to create the initial instruction
233 /// itself.
234 ///
BuildMI(MachineFunction & MF,DebugLoc DL,const MCInstrDesc & MCID)235 inline MachineInstrBuilder BuildMI(MachineFunction &MF,
236                                    DebugLoc DL,
237                                    const MCInstrDesc &MCID) {
238   return MachineInstrBuilder(MF, MF.CreateMachineInstr(MCID, DL));
239 }
240 
241 /// BuildMI - This version of the builder sets up the first operand as a
242 /// destination virtual register.
243 ///
BuildMI(MachineFunction & MF,DebugLoc DL,const MCInstrDesc & MCID,unsigned DestReg)244 inline MachineInstrBuilder BuildMI(MachineFunction &MF,
245                                    DebugLoc DL,
246                                    const MCInstrDesc &MCID,
247                                    unsigned DestReg) {
248   return MachineInstrBuilder(MF, MF.CreateMachineInstr(MCID, DL))
249            .addReg(DestReg, RegState::Define);
250 }
251 
252 /// BuildMI - This version of the builder inserts the newly-built
253 /// instruction before the given position in the given MachineBasicBlock, and
254 /// sets up the first operand as a destination virtual register.
255 ///
BuildMI(MachineBasicBlock & BB,MachineBasicBlock::iterator I,DebugLoc DL,const MCInstrDesc & MCID,unsigned DestReg)256 inline MachineInstrBuilder BuildMI(MachineBasicBlock &BB,
257                                    MachineBasicBlock::iterator I,
258                                    DebugLoc DL,
259                                    const MCInstrDesc &MCID,
260                                    unsigned DestReg) {
261   MachineFunction &MF = *BB.getParent();
262   MachineInstr *MI = MF.CreateMachineInstr(MCID, DL);
263   BB.insert(I, MI);
264   return MachineInstrBuilder(MF, MI).addReg(DestReg, RegState::Define);
265 }
266 
BuildMI(MachineBasicBlock & BB,MachineBasicBlock::instr_iterator I,DebugLoc DL,const MCInstrDesc & MCID,unsigned DestReg)267 inline MachineInstrBuilder BuildMI(MachineBasicBlock &BB,
268                                    MachineBasicBlock::instr_iterator I,
269                                    DebugLoc DL,
270                                    const MCInstrDesc &MCID,
271                                    unsigned DestReg) {
272   MachineFunction &MF = *BB.getParent();
273   MachineInstr *MI = MF.CreateMachineInstr(MCID, DL);
274   BB.insert(I, MI);
275   return MachineInstrBuilder(MF, MI).addReg(DestReg, RegState::Define);
276 }
277 
BuildMI(MachineBasicBlock & BB,MachineInstr * I,DebugLoc DL,const MCInstrDesc & MCID,unsigned DestReg)278 inline MachineInstrBuilder BuildMI(MachineBasicBlock &BB,
279                                    MachineInstr *I,
280                                    DebugLoc DL,
281                                    const MCInstrDesc &MCID,
282                                    unsigned DestReg) {
283   if (I->isInsideBundle()) {
284     MachineBasicBlock::instr_iterator MII = I;
285     return BuildMI(BB, MII, DL, MCID, DestReg);
286   }
287 
288   MachineBasicBlock::iterator MII = I;
289   return BuildMI(BB, MII, DL, MCID, DestReg);
290 }
291 
292 /// BuildMI - This version of the builder inserts the newly-built
293 /// instruction before the given position in the given MachineBasicBlock, and
294 /// does NOT take a destination register.
295 ///
BuildMI(MachineBasicBlock & BB,MachineBasicBlock::iterator I,DebugLoc DL,const MCInstrDesc & MCID)296 inline MachineInstrBuilder BuildMI(MachineBasicBlock &BB,
297                                    MachineBasicBlock::iterator I,
298                                    DebugLoc DL,
299                                    const MCInstrDesc &MCID) {
300   MachineFunction &MF = *BB.getParent();
301   MachineInstr *MI = MF.CreateMachineInstr(MCID, DL);
302   BB.insert(I, MI);
303   return MachineInstrBuilder(MF, MI);
304 }
305 
BuildMI(MachineBasicBlock & BB,MachineBasicBlock::instr_iterator I,DebugLoc DL,const MCInstrDesc & MCID)306 inline MachineInstrBuilder BuildMI(MachineBasicBlock &BB,
307                                    MachineBasicBlock::instr_iterator I,
308                                    DebugLoc DL,
309                                    const MCInstrDesc &MCID) {
310   MachineFunction &MF = *BB.getParent();
311   MachineInstr *MI = MF.CreateMachineInstr(MCID, DL);
312   BB.insert(I, MI);
313   return MachineInstrBuilder(MF, MI);
314 }
315 
BuildMI(MachineBasicBlock & BB,MachineInstr * I,DebugLoc DL,const MCInstrDesc & MCID)316 inline MachineInstrBuilder BuildMI(MachineBasicBlock &BB,
317                                    MachineInstr *I,
318                                    DebugLoc DL,
319                                    const MCInstrDesc &MCID) {
320   if (I->isInsideBundle()) {
321     MachineBasicBlock::instr_iterator MII = I;
322     return BuildMI(BB, MII, DL, MCID);
323   }
324 
325   MachineBasicBlock::iterator MII = I;
326   return BuildMI(BB, MII, DL, MCID);
327 }
328 
329 /// BuildMI - This version of the builder inserts the newly-built
330 /// instruction at the end of the given MachineBasicBlock, and does NOT take a
331 /// destination register.
332 ///
BuildMI(MachineBasicBlock * BB,DebugLoc DL,const MCInstrDesc & MCID)333 inline MachineInstrBuilder BuildMI(MachineBasicBlock *BB,
334                                    DebugLoc DL,
335                                    const MCInstrDesc &MCID) {
336   return BuildMI(*BB, BB->end(), DL, MCID);
337 }
338 
339 /// BuildMI - This version of the builder inserts the newly-built
340 /// instruction at the end of the given MachineBasicBlock, and sets up the first
341 /// operand as a destination virtual register.
342 ///
BuildMI(MachineBasicBlock * BB,DebugLoc DL,const MCInstrDesc & MCID,unsigned DestReg)343 inline MachineInstrBuilder BuildMI(MachineBasicBlock *BB,
344                                    DebugLoc DL,
345                                    const MCInstrDesc &MCID,
346                                    unsigned DestReg) {
347   return BuildMI(*BB, BB->end(), DL, MCID, DestReg);
348 }
349 
350 /// BuildMI - This version of the builder builds a DBG_VALUE intrinsic
351 /// for either a value in a register or a register-indirect+offset
352 /// address.  The convention is that a DBG_VALUE is indirect iff the
353 /// second operand is an immediate.
354 ///
BuildMI(MachineFunction & MF,DebugLoc DL,const MCInstrDesc & MCID,bool IsIndirect,unsigned Reg,unsigned Offset,const MDNode * Variable,const MDNode * Expr)355 inline MachineInstrBuilder BuildMI(MachineFunction &MF, DebugLoc DL,
356                                    const MCInstrDesc &MCID, bool IsIndirect,
357                                    unsigned Reg, unsigned Offset,
358                                    const MDNode *Variable, const MDNode *Expr) {
359   assert(isa<MDLocalVariable>(Variable) && "not a DIVariable");
360   assert(cast<MDExpression>(Expr)->isValid() && "not a DIExpression");
361   assert(cast<MDLocalVariable>(Variable)->isValidLocationForIntrinsic(DL) &&
362          "Expected inlined-at fields to agree");
363   if (IsIndirect)
364     return BuildMI(MF, DL, MCID)
365         .addReg(Reg, RegState::Debug)
366         .addImm(Offset)
367         .addMetadata(Variable)
368         .addMetadata(Expr);
369   else {
370     assert(Offset == 0 && "A direct address cannot have an offset.");
371     return BuildMI(MF, DL, MCID)
372         .addReg(Reg, RegState::Debug)
373         .addReg(0U, RegState::Debug)
374         .addMetadata(Variable)
375         .addMetadata(Expr);
376   }
377 }
378 
379 /// BuildMI - This version of the builder builds a DBG_VALUE intrinsic
380 /// for either a value in a register or a register-indirect+offset
381 /// address and inserts it at position I.
382 ///
BuildMI(MachineBasicBlock & BB,MachineBasicBlock::iterator I,DebugLoc DL,const MCInstrDesc & MCID,bool IsIndirect,unsigned Reg,unsigned Offset,const MDNode * Variable,const MDNode * Expr)383 inline MachineInstrBuilder BuildMI(MachineBasicBlock &BB,
384                                    MachineBasicBlock::iterator I, DebugLoc DL,
385                                    const MCInstrDesc &MCID, bool IsIndirect,
386                                    unsigned Reg, unsigned Offset,
387                                    const MDNode *Variable, const MDNode *Expr) {
388   assert(isa<MDLocalVariable>(Variable) && "not a DIVariable");
389   assert(cast<MDExpression>(Expr)->isValid() && "not a DIExpression");
390   MachineFunction &MF = *BB.getParent();
391   MachineInstr *MI =
392       BuildMI(MF, DL, MCID, IsIndirect, Reg, Offset, Variable, Expr);
393   BB.insert(I, MI);
394   return MachineInstrBuilder(MF, MI);
395 }
396 
397 
getDefRegState(bool B)398 inline unsigned getDefRegState(bool B) {
399   return B ? RegState::Define : 0;
400 }
getImplRegState(bool B)401 inline unsigned getImplRegState(bool B) {
402   return B ? RegState::Implicit : 0;
403 }
getKillRegState(bool B)404 inline unsigned getKillRegState(bool B) {
405   return B ? RegState::Kill : 0;
406 }
getDeadRegState(bool B)407 inline unsigned getDeadRegState(bool B) {
408   return B ? RegState::Dead : 0;
409 }
getUndefRegState(bool B)410 inline unsigned getUndefRegState(bool B) {
411   return B ? RegState::Undef : 0;
412 }
getInternalReadRegState(bool B)413 inline unsigned getInternalReadRegState(bool B) {
414   return B ? RegState::InternalRead : 0;
415 }
getDebugRegState(bool B)416 inline unsigned getDebugRegState(bool B) {
417   return B ? RegState::Debug : 0;
418 }
419 
420 
421 /// Helper class for constructing bundles of MachineInstrs.
422 ///
423 /// MIBundleBuilder can create a bundle from scratch by inserting new
424 /// MachineInstrs one at a time, or it can create a bundle from a sequence of
425 /// existing MachineInstrs in a basic block.
426 class MIBundleBuilder {
427   MachineBasicBlock &MBB;
428   MachineBasicBlock::instr_iterator Begin;
429   MachineBasicBlock::instr_iterator End;
430 
431 public:
432   /// Create an MIBundleBuilder that inserts instructions into a new bundle in
433   /// BB above the bundle or instruction at Pos.
MIBundleBuilder(MachineBasicBlock & BB,MachineBasicBlock::iterator Pos)434   MIBundleBuilder(MachineBasicBlock &BB,
435                   MachineBasicBlock::iterator Pos)
436     : MBB(BB), Begin(Pos.getInstrIterator()), End(Begin) {}
437 
438   /// Create a bundle from the sequence of instructions between B and E.
MIBundleBuilder(MachineBasicBlock & BB,MachineBasicBlock::iterator B,MachineBasicBlock::iterator E)439   MIBundleBuilder(MachineBasicBlock &BB,
440                   MachineBasicBlock::iterator B,
441                   MachineBasicBlock::iterator E)
442     : MBB(BB), Begin(B.getInstrIterator()), End(E.getInstrIterator()) {
443     assert(B != E && "No instructions to bundle");
444     ++B;
445     while (B != E) {
446       MachineInstr *MI = B;
447       ++B;
448       MI->bundleWithPred();
449     }
450   }
451 
452   /// Create an MIBundleBuilder representing an existing instruction or bundle
453   /// that has MI as its head.
MIBundleBuilder(MachineInstr * MI)454   explicit MIBundleBuilder(MachineInstr *MI)
455     : MBB(*MI->getParent()), Begin(MI), End(getBundleEnd(MI)) {}
456 
457   /// Return a reference to the basic block containing this bundle.
getMBB()458   MachineBasicBlock &getMBB() const { return MBB; }
459 
460   /// Return true if no instructions have been inserted in this bundle yet.
461   /// Empty bundles aren't representable in a MachineBasicBlock.
empty()462   bool empty() const { return Begin == End; }
463 
464   /// Return an iterator to the first bundled instruction.
begin()465   MachineBasicBlock::instr_iterator begin() const { return Begin; }
466 
467   /// Return an iterator beyond the last bundled instruction.
end()468   MachineBasicBlock::instr_iterator end() const { return End; }
469 
470   /// Insert MI into this bundle before I which must point to an instruction in
471   /// the bundle, or end().
insert(MachineBasicBlock::instr_iterator I,MachineInstr * MI)472   MIBundleBuilder &insert(MachineBasicBlock::instr_iterator I,
473                           MachineInstr *MI) {
474     MBB.insert(I, MI);
475     if (I == Begin) {
476       if (!empty())
477         MI->bundleWithSucc();
478       Begin = MI;
479       return *this;
480     }
481     if (I == End) {
482       MI->bundleWithPred();
483       return *this;
484     }
485     // MI was inserted in the middle of the bundle, so its neighbors' flags are
486     // already fine. Update MI's bundle flags manually.
487     MI->setFlag(MachineInstr::BundledPred);
488     MI->setFlag(MachineInstr::BundledSucc);
489     return *this;
490   }
491 
492   /// Insert MI into MBB by prepending it to the instructions in the bundle.
493   /// MI will become the first instruction in the bundle.
prepend(MachineInstr * MI)494   MIBundleBuilder &prepend(MachineInstr *MI) {
495     return insert(begin(), MI);
496   }
497 
498   /// Insert MI into MBB by appending it to the instructions in the bundle.
499   /// MI will become the last instruction in the bundle.
append(MachineInstr * MI)500   MIBundleBuilder &append(MachineInstr *MI) {
501     return insert(end(), MI);
502   }
503 };
504 
505 } // End llvm namespace
506 
507 #endif
508