MachineInstrBuilder.h revision 7f4bb1b9f0c1a4b5191c4e4892356fa5c75a0aaa 
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/Support/ErrorHandling.h"
22
23namespace llvm {
24
25class MCInstrDesc;
26class MDNode;
27
28namespace RegState {
29  enum {
30    Define         = 0x2,
31    Implicit       = 0x4,
32    Kill           = 0x8,
33    Dead           = 0x10,
34    Undef          = 0x20,
35    EarlyClobber   = 0x40,
36    Debug          = 0x80,
37    InternalRead   = 0x100,
38    DefineNoRead   = Define | Undef,
39    ImplicitDefine = Implicit | Define,
40    ImplicitKill   = Implicit | Kill
41  };
42}
43
44class MachineInstrBuilder {
45  MachineFunction *MF;
46  MachineInstr *MI;
47public:
48  MachineInstrBuilder() : MF(0), MI(0) {}
49
50  /// Create a MachineInstrBuilder for manipulating an existing instruction.
51  /// F must be the machine function  that was used to allocate I.
52  MachineInstrBuilder(MachineFunction &F, MachineInstr *I) : MF(&F), MI(I) {}
53
54  /// Allow automatic conversion to the machine instruction we are working on.
55  ///
56  operator MachineInstr*() const { return MI; }
57  MachineInstr *operator->() const { return MI; }
58  operator MachineBasicBlock::iterator() const { return MI; }
59
60  /// addReg - Add a new virtual register operand...
61  ///
62  const
63  MachineInstrBuilder &addReg(unsigned RegNo, unsigned flags = 0,
64                              unsigned SubReg = 0) const {
65    assert((flags & 0x1) == 0 &&
66           "Passing in 'true' to addReg is forbidden! Use enums instead.");
67    MI->addOperand(*MF, MachineOperand::CreateReg(RegNo,
68                                               flags & RegState::Define,
69                                               flags & RegState::Implicit,
70                                               flags & RegState::Kill,
71                                               flags & RegState::Dead,
72                                               flags & RegState::Undef,
73                                               flags & RegState::EarlyClobber,
74                                               SubReg,
75                                               flags & RegState::Debug,
76                                               flags & RegState::InternalRead));
77    return *this;
78  }
79
80  /// addImm - Add a new immediate operand.
81  ///
82  const MachineInstrBuilder &addImm(int64_t Val) const {
83    MI->addOperand(*MF, MachineOperand::CreateImm(Val));
84    return *this;
85  }
86
87  const MachineInstrBuilder &addCImm(const ConstantInt *Val) const {
88    MI->addOperand(*MF, MachineOperand::CreateCImm(Val));
89    return *this;
90  }
91
92  const MachineInstrBuilder &addFPImm(const ConstantFP *Val) const {
93    MI->addOperand(*MF, MachineOperand::CreateFPImm(Val));
94    return *this;
95  }
96
97  const MachineInstrBuilder &addMBB(MachineBasicBlock *MBB,
98                                    unsigned char TargetFlags = 0) const {
99    MI->addOperand(*MF, MachineOperand::CreateMBB(MBB, TargetFlags));
100    return *this;
101  }
102
103  const MachineInstrBuilder &addFrameIndex(int Idx) const {
104    MI->addOperand(*MF, MachineOperand::CreateFI(Idx));
105    return *this;
106  }
107
108  const MachineInstrBuilder &addConstantPoolIndex(unsigned Idx,
109                                                  int Offset = 0,
110                                          unsigned char TargetFlags = 0) const {
111    MI->addOperand(*MF, MachineOperand::CreateCPI(Idx, Offset, TargetFlags));
112    return *this;
113  }
114
115  const MachineInstrBuilder &addTargetIndex(unsigned Idx, int64_t Offset = 0,
116                                          unsigned char TargetFlags = 0) const {
117    MI->addOperand(*MF, MachineOperand::CreateTargetIndex(Idx, Offset,
118                                                          TargetFlags));
119    return *this;
120  }
121
122  const MachineInstrBuilder &addJumpTableIndex(unsigned Idx,
123                                          unsigned char TargetFlags = 0) const {
124    MI->addOperand(*MF, MachineOperand::CreateJTI(Idx, TargetFlags));
125    return *this;
126  }
127
128  const MachineInstrBuilder &addGlobalAddress(const GlobalValue *GV,
129                                              int64_t Offset = 0,
130                                          unsigned char TargetFlags = 0) const {
131    MI->addOperand(*MF, MachineOperand::CreateGA(GV, Offset, TargetFlags));
132    return *this;
133  }
134
135  const MachineInstrBuilder &addExternalSymbol(const char *FnName,
136                                          unsigned char TargetFlags = 0) const {
137    MI->addOperand(*MF, MachineOperand::CreateES(FnName, TargetFlags));
138    return *this;
139  }
140
141  const MachineInstrBuilder &addRegMask(const uint32_t *Mask) const {
142    MI->addOperand(*MF, MachineOperand::CreateRegMask(Mask));
143    return *this;
144  }
145
146  const MachineInstrBuilder &addMemOperand(MachineMemOperand *MMO) const {
147    MI->addMemOperand(*MF, MMO);
148    return *this;
149  }
150
151  const MachineInstrBuilder &setMemRefs(MachineInstr::mmo_iterator b,
152                                        MachineInstr::mmo_iterator e) const {
153    MI->setMemRefs(b, e);
154    return *this;
155  }
156
157
158  const MachineInstrBuilder &addOperand(const MachineOperand &MO) const {
159    MI->addOperand(*MF, MO);
160    return *this;
161  }
162
163  const MachineInstrBuilder &addMetadata(const MDNode *MD) const {
164    MI->addOperand(*MF, MachineOperand::CreateMetadata(MD));
165    return *this;
166  }
167
168  const MachineInstrBuilder &addSym(MCSymbol *Sym) const {
169    MI->addOperand(*MF, MachineOperand::CreateMCSymbol(Sym));
170    return *this;
171  }
172
173  const MachineInstrBuilder &setMIFlags(unsigned Flags) const {
174    MI->setFlags(Flags);
175    return *this;
176  }
177
178  const MachineInstrBuilder &setMIFlag(MachineInstr::MIFlag Flag) const {
179    MI->setFlag(Flag);
180    return *this;
181  }
182
183  // Add a displacement from an existing MachineOperand with an added offset.
184  const MachineInstrBuilder &addDisp(const MachineOperand &Disp, int64_t off,
185                                     unsigned char TargetFlags = 0) const {
186    switch (Disp.getType()) {
187      default:
188        llvm_unreachable("Unhandled operand type in addDisp()");
189      case MachineOperand::MO_Immediate:
190        return addImm(Disp.getImm() + off);
191      case MachineOperand::MO_GlobalAddress: {
192        // If caller specifies new TargetFlags then use it, otherwise the
193        // default behavior is to copy the target flags from the existing
194        // MachineOperand. This means if the caller wants to clear the
195        // target flags it needs to do so explicitly.
196        if (TargetFlags)
197          return addGlobalAddress(Disp.getGlobal(), Disp.getOffset() + off,
198                                  TargetFlags);
199        return addGlobalAddress(Disp.getGlobal(), Disp.getOffset() + off,
200                                Disp.getTargetFlags());
201      }
202    }
203  }
204};
205
206/// BuildMI - Builder interface.  Specify how to create the initial instruction
207/// itself.
208///
209inline MachineInstrBuilder BuildMI(MachineFunction &MF,
210                                   DebugLoc DL,
211                                   const MCInstrDesc &MCID) {
212  return MachineInstrBuilder(MF, MF.CreateMachineInstr(MCID, DL));
213}
214
215/// BuildMI - This version of the builder sets up the first operand as a
216/// destination virtual register.
217///
218inline MachineInstrBuilder BuildMI(MachineFunction &MF,
219                                   DebugLoc DL,
220                                   const MCInstrDesc &MCID,
221                                   unsigned DestReg) {
222  return MachineInstrBuilder(MF, MF.CreateMachineInstr(MCID, DL))
223           .addReg(DestReg, RegState::Define);
224}
225
226/// BuildMI - This version of the builder inserts the newly-built
227/// instruction before the given position in the given MachineBasicBlock, and
228/// sets up the first operand as a destination virtual register.
229///
230inline MachineInstrBuilder BuildMI(MachineBasicBlock &BB,
231                                   MachineBasicBlock::iterator I,
232                                   DebugLoc DL,
233                                   const MCInstrDesc &MCID,
234                                   unsigned DestReg) {
235  MachineFunction &MF = *BB.getParent();
236  MachineInstr *MI = MF.CreateMachineInstr(MCID, DL);
237  BB.insert(I, MI);
238  return MachineInstrBuilder(MF, MI).addReg(DestReg, RegState::Define);
239}
240
241inline MachineInstrBuilder BuildMI(MachineBasicBlock &BB,
242                                   MachineBasicBlock::instr_iterator I,
243                                   DebugLoc DL,
244                                   const MCInstrDesc &MCID,
245                                   unsigned DestReg) {
246  MachineFunction &MF = *BB.getParent();
247  MachineInstr *MI = MF.CreateMachineInstr(MCID, DL);
248  BB.insert(I, MI);
249  return MachineInstrBuilder(MF, MI).addReg(DestReg, RegState::Define);
250}
251
252inline MachineInstrBuilder BuildMI(MachineBasicBlock &BB,
253                                   MachineInstr *I,
254                                   DebugLoc DL,
255                                   const MCInstrDesc &MCID,
256                                   unsigned DestReg) {
257  if (I->isInsideBundle()) {
258    MachineBasicBlock::instr_iterator MII = I;
259    return BuildMI(BB, MII, DL, MCID, DestReg);
260  }
261
262  MachineBasicBlock::iterator MII = I;
263  return BuildMI(BB, MII, DL, MCID, DestReg);
264}
265
266/// BuildMI - This version of the builder inserts the newly-built
267/// instruction before the given position in the given MachineBasicBlock, and
268/// does NOT take a destination register.
269///
270inline MachineInstrBuilder BuildMI(MachineBasicBlock &BB,
271                                   MachineBasicBlock::iterator I,
272                                   DebugLoc DL,
273                                   const MCInstrDesc &MCID) {
274  MachineFunction &MF = *BB.getParent();
275  MachineInstr *MI = MF.CreateMachineInstr(MCID, DL);
276  BB.insert(I, MI);
277  return MachineInstrBuilder(MF, MI);
278}
279
280inline MachineInstrBuilder BuildMI(MachineBasicBlock &BB,
281                                   MachineBasicBlock::instr_iterator I,
282                                   DebugLoc DL,
283                                   const MCInstrDesc &MCID) {
284  MachineFunction &MF = *BB.getParent();
285  MachineInstr *MI = MF.CreateMachineInstr(MCID, DL);
286  BB.insert(I, MI);
287  return MachineInstrBuilder(MF, MI);
288}
289
290inline MachineInstrBuilder BuildMI(MachineBasicBlock &BB,
291                                   MachineInstr *I,
292                                   DebugLoc DL,
293                                   const MCInstrDesc &MCID) {
294  if (I->isInsideBundle()) {
295    MachineBasicBlock::instr_iterator MII = I;
296    return BuildMI(BB, MII, DL, MCID);
297  }
298
299  MachineBasicBlock::iterator MII = I;
300  return BuildMI(BB, MII, DL, MCID);
301}
302
303/// BuildMI - This version of the builder inserts the newly-built
304/// instruction at the end of the given MachineBasicBlock, and does NOT take a
305/// destination register.
306///
307inline MachineInstrBuilder BuildMI(MachineBasicBlock *BB,
308                                   DebugLoc DL,
309                                   const MCInstrDesc &MCID) {
310  return BuildMI(*BB, BB->end(), DL, MCID);
311}
312
313/// BuildMI - This version of the builder inserts the newly-built
314/// instruction at the end of the given MachineBasicBlock, and sets up the first
315/// operand as a destination virtual register.
316///
317inline MachineInstrBuilder BuildMI(MachineBasicBlock *BB,
318                                   DebugLoc DL,
319                                   const MCInstrDesc &MCID,
320                                   unsigned DestReg) {
321  return BuildMI(*BB, BB->end(), DL, MCID, DestReg);
322}
323
324inline unsigned getDefRegState(bool B) {
325  return B ? RegState::Define : 0;
326}
327inline unsigned getImplRegState(bool B) {
328  return B ? RegState::Implicit : 0;
329}
330inline unsigned getKillRegState(bool B) {
331  return B ? RegState::Kill : 0;
332}
333inline unsigned getDeadRegState(bool B) {
334  return B ? RegState::Dead : 0;
335}
336inline unsigned getUndefRegState(bool B) {
337  return B ? RegState::Undef : 0;
338}
339inline unsigned getInternalReadRegState(bool B) {
340  return B ? RegState::InternalRead : 0;
341}
342
343
344/// Helper class for constructing bundles of MachineInstrs.
345///
346/// MIBundleBuilder can create a bundle from scratch by inserting new
347/// MachineInstrs one at a time, or it can create a bundle from a sequence of
348/// existing MachineInstrs in a basic block.
349class MIBundleBuilder {
350  MachineBasicBlock &MBB;
351  MachineBasicBlock::instr_iterator Begin;
352  MachineBasicBlock::instr_iterator End;
353
354public:
355  /// Create an MIBundleBuilder that inserts instructions into a new bundle in
356  /// BB above the bundle or instruction at Pos.
357  MIBundleBuilder(MachineBasicBlock &BB,
358                  MachineBasicBlock::iterator Pos)
359    : MBB(BB), Begin(Pos.getInstrIterator()), End(Begin) {}
360
361  /// Create a bundle from the sequence of instructions between B and E.
362  MIBundleBuilder(MachineBasicBlock &BB,
363                  MachineBasicBlock::iterator B,
364                  MachineBasicBlock::iterator E)
365    : MBB(BB), Begin(B.getInstrIterator()), End(E.getInstrIterator()) {
366    assert(B != E && "No instructions to bundle");
367    ++B;
368    while (B != E) {
369      MachineInstr *MI = B;
370      ++B;
371      MI->bundleWithPred();
372    }
373  }
374
375  /// Create an MIBundleBuilder representing an existing instruction or bundle
376  /// that has MI as its head.
377  explicit MIBundleBuilder(MachineInstr *MI)
378    : MBB(*MI->getParent()), Begin(MI) {
379    MachineBasicBlock::iterator I = MI;
380    ++I;
381    End = I.getInstrIterator();
382  }
383
384  /// Return a reference to the basic block containing this bundle.
385  MachineBasicBlock &getMBB() const { return MBB; }
386
387  /// Return true if no instructions have been inserted in this bundle yet.
388  /// Empty bundles aren't representable in a MachineBasicBlock.
389  bool empty() const { return Begin == End; }
390
391  /// Return an iterator to the first bundled instruction.
392  MachineBasicBlock::instr_iterator begin() const { return Begin; }
393
394  /// Return an iterator beyond the last bundled instruction.
395  MachineBasicBlock::instr_iterator end() const { return End; }
396
397  /// Insert MI into this bundle before I which must point to an instruction in
398  /// the bundle, or end().
399  MIBundleBuilder &insert(MachineBasicBlock::instr_iterator I,
400                          MachineInstr *MI) {
401    MBB.insert(I, MI);
402    if (I == Begin) {
403      if (!empty())
404        MI->bundleWithSucc();
405      Begin = MI;
406      return *this;
407    }
408    if (I == End) {
409      MI->bundleWithPred();
410      return *this;
411    }
412    // MI was inserted in the middle of the bundle, so its neighbors' flags are
413    // already fine. Update MI's bundle flags manually.
414    MI->setFlag(MachineInstr::BundledPred);
415    MI->setFlag(MachineInstr::BundledSucc);
416    return *this;
417  }
418
419  /// Insert MI into MBB by prepending it to the instructions in the bundle.
420  /// MI will become the first instruction in the bundle.
421  MIBundleBuilder &prepend(MachineInstr *MI) {
422    return insert(begin(), MI);
423  }
424
425  /// Insert MI into MBB by appending it to the instructions in the bundle.
426  /// MI will become the last instruction in the bundle.
427  MIBundleBuilder &append(MachineInstr *MI) {
428    return insert(end(), MI);
429  }
430};
431
432} // End llvm namespace
433
434#endif
435