MachineInstrBuilder.h revision 5d7802ceccdaaaec1b7612ef4adb90dbaa278ece 
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  MachineInstr *MI;
46public:
47  MachineInstrBuilder() : MI(0) {}
48  explicit MachineInstrBuilder(MachineInstr *mi) : MI(mi) {}
49
50  /// Allow automatic conversion to the machine instruction we are working on.
51  ///
52  operator MachineInstr*() const { return MI; }
53  MachineInstr *operator->() const { return MI; }
54  operator MachineBasicBlock::iterator() const { return MI; }
55
56  /// addReg - Add a new virtual register operand...
57  ///
58  const
59  MachineInstrBuilder &addReg(unsigned RegNo, unsigned flags = 0,
60                              unsigned SubReg = 0) const {
61    assert((flags & 0x1) == 0 &&
62           "Passing in 'true' to addReg is forbidden! Use enums instead.");
63    MI->addOperand(MachineOperand::CreateReg(RegNo,
64                                             flags & RegState::Define,
65                                             flags & RegState::Implicit,
66                                             flags & RegState::Kill,
67                                             flags & RegState::Dead,
68                                             flags & RegState::Undef,
69                                             flags & RegState::EarlyClobber,
70                                             SubReg,
71                                             flags & RegState::Debug,
72                                             flags & RegState::InternalRead));
73    return *this;
74  }
75
76  /// addImm - Add a new immediate operand.
77  ///
78  const MachineInstrBuilder &addImm(int64_t Val) const {
79    MI->addOperand(MachineOperand::CreateImm(Val));
80    return *this;
81  }
82
83  const MachineInstrBuilder &addCImm(const ConstantInt *Val) const {
84    MI->addOperand(MachineOperand::CreateCImm(Val));
85    return *this;
86  }
87
88  const MachineInstrBuilder &addFPImm(const ConstantFP *Val) const {
89    MI->addOperand(MachineOperand::CreateFPImm(Val));
90    return *this;
91  }
92
93  const MachineInstrBuilder &addMBB(MachineBasicBlock *MBB,
94                                    unsigned char TargetFlags = 0) const {
95    MI->addOperand(MachineOperand::CreateMBB(MBB, TargetFlags));
96    return *this;
97  }
98
99  const MachineInstrBuilder &addFrameIndex(int Idx) const {
100    MI->addOperand(MachineOperand::CreateFI(Idx));
101    return *this;
102  }
103
104  const MachineInstrBuilder &addConstantPoolIndex(unsigned Idx,
105                                                  int Offset = 0,
106                                          unsigned char TargetFlags = 0) const {
107    MI->addOperand(MachineOperand::CreateCPI(Idx, Offset, TargetFlags));
108    return *this;
109  }
110
111  const MachineInstrBuilder &addTargetIndex(unsigned Idx, int64_t Offset = 0,
112                                          unsigned char TargetFlags = 0) const {
113    MI->addOperand(MachineOperand::CreateTargetIndex(Idx, Offset, TargetFlags));
114    return *this;
115  }
116
117  const MachineInstrBuilder &addJumpTableIndex(unsigned Idx,
118                                          unsigned char TargetFlags = 0) const {
119    MI->addOperand(MachineOperand::CreateJTI(Idx, TargetFlags));
120    return *this;
121  }
122
123  const MachineInstrBuilder &addGlobalAddress(const GlobalValue *GV,
124                                              int64_t Offset = 0,
125                                          unsigned char TargetFlags = 0) const {
126    MI->addOperand(MachineOperand::CreateGA(GV, Offset, TargetFlags));
127    return *this;
128  }
129
130  const MachineInstrBuilder &addExternalSymbol(const char *FnName,
131                                          unsigned char TargetFlags = 0) const {
132    MI->addOperand(MachineOperand::CreateES(FnName, TargetFlags));
133    return *this;
134  }
135
136  const MachineInstrBuilder &addRegMask(const uint32_t *Mask) const {
137    MI->addOperand(MachineOperand::CreateRegMask(Mask));
138    return *this;
139  }
140
141  const MachineInstrBuilder &addMemOperand(MachineMemOperand *MMO) const {
142    MI->addMemOperand(*MI->getParent()->getParent(), MMO);
143    return *this;
144  }
145
146  const MachineInstrBuilder &setMemRefs(MachineInstr::mmo_iterator b,
147                                        MachineInstr::mmo_iterator e) const {
148    MI->setMemRefs(b, e);
149    return *this;
150  }
151
152
153  const MachineInstrBuilder &addOperand(const MachineOperand &MO) const {
154    MI->addOperand(MO);
155    return *this;
156  }
157
158  const MachineInstrBuilder &addMetadata(const MDNode *MD) const {
159    MI->addOperand(MachineOperand::CreateMetadata(MD));
160    return *this;
161  }
162
163  const MachineInstrBuilder &addSym(MCSymbol *Sym) const {
164    MI->addOperand(MachineOperand::CreateMCSymbol(Sym));
165    return *this;
166  }
167
168  const MachineInstrBuilder &setMIFlags(unsigned Flags) const {
169    MI->setFlags(Flags);
170    return *this;
171  }
172
173  const MachineInstrBuilder &setMIFlag(MachineInstr::MIFlag Flag) const {
174    MI->setFlag(Flag);
175    return *this;
176  }
177
178  // Add a displacement from an existing MachineOperand with an added offset.
179  const MachineInstrBuilder &addDisp(const MachineOperand &Disp, int64_t off,
180                                     unsigned char TargetFlags = 0) const {
181    switch (Disp.getType()) {
182      default:
183        llvm_unreachable("Unhandled operand type in addDisp()");
184      case MachineOperand::MO_Immediate:
185        return addImm(Disp.getImm() + off);
186      case MachineOperand::MO_GlobalAddress: {
187        // If caller specifies new TargetFlags then use it, otherwise the
188        // default behavior is to copy the target flags from the existing
189        // MachineOperand. This means if the caller wants to clear the
190        // target flags it needs to do so explicitly.
191        if (TargetFlags)
192          return addGlobalAddress(Disp.getGlobal(), Disp.getOffset() + off,
193                                  TargetFlags);
194        return addGlobalAddress(Disp.getGlobal(), Disp.getOffset() + off,
195                                Disp.getTargetFlags());
196      }
197    }
198  }
199};
200
201/// BuildMI - Builder interface.  Specify how to create the initial instruction
202/// itself.
203///
204inline MachineInstrBuilder BuildMI(MachineFunction &MF,
205                                   DebugLoc DL,
206                                   const MCInstrDesc &MCID) {
207  return MachineInstrBuilder(MF.CreateMachineInstr(MCID, DL));
208}
209
210/// BuildMI - This version of the builder sets up the first operand as a
211/// destination virtual register.
212///
213inline MachineInstrBuilder BuildMI(MachineFunction &MF,
214                                   DebugLoc DL,
215                                   const MCInstrDesc &MCID,
216                                   unsigned DestReg) {
217  return MachineInstrBuilder(MF.CreateMachineInstr(MCID, DL))
218           .addReg(DestReg, RegState::Define);
219}
220
221/// BuildMI - This version of the builder inserts the newly-built
222/// instruction before the given position in the given MachineBasicBlock, and
223/// sets up the first operand as a destination virtual register.
224///
225inline MachineInstrBuilder BuildMI(MachineBasicBlock &BB,
226                                   MachineBasicBlock::iterator I,
227                                   DebugLoc DL,
228                                   const MCInstrDesc &MCID,
229                                   unsigned DestReg) {
230  MachineInstr *MI = BB.getParent()->CreateMachineInstr(MCID, DL);
231  BB.insert(I, MI);
232  return MachineInstrBuilder(MI).addReg(DestReg, RegState::Define);
233}
234
235inline MachineInstrBuilder BuildMI(MachineBasicBlock &BB,
236                                   MachineBasicBlock::instr_iterator I,
237                                   DebugLoc DL,
238                                   const MCInstrDesc &MCID,
239                                   unsigned DestReg) {
240  MachineInstr *MI = BB.getParent()->CreateMachineInstr(MCID, DL);
241  BB.insert(I, MI);
242  return MachineInstrBuilder(MI).addReg(DestReg, RegState::Define);
243}
244
245inline MachineInstrBuilder BuildMI(MachineBasicBlock &BB,
246                                   MachineInstr *I,
247                                   DebugLoc DL,
248                                   const MCInstrDesc &MCID,
249                                   unsigned DestReg) {
250  if (I->isInsideBundle()) {
251    MachineBasicBlock::instr_iterator MII = I;
252    return BuildMI(BB, MII, DL, MCID, DestReg);
253  }
254
255  MachineBasicBlock::iterator MII = I;
256  return BuildMI(BB, MII, DL, MCID, DestReg);
257}
258
259/// BuildMI - This version of the builder inserts the newly-built
260/// instruction before the given position in the given MachineBasicBlock, and
261/// does NOT take a destination register.
262///
263inline MachineInstrBuilder BuildMI(MachineBasicBlock &BB,
264                                   MachineBasicBlock::iterator I,
265                                   DebugLoc DL,
266                                   const MCInstrDesc &MCID) {
267  MachineInstr *MI = BB.getParent()->CreateMachineInstr(MCID, DL);
268  BB.insert(I, MI);
269  return MachineInstrBuilder(MI);
270}
271
272inline MachineInstrBuilder BuildMI(MachineBasicBlock &BB,
273                                   MachineBasicBlock::instr_iterator I,
274                                   DebugLoc DL,
275                                   const MCInstrDesc &MCID) {
276  MachineInstr *MI = BB.getParent()->CreateMachineInstr(MCID, DL);
277  BB.insert(I, MI);
278  return MachineInstrBuilder(MI);
279}
280
281inline MachineInstrBuilder BuildMI(MachineBasicBlock &BB,
282                                   MachineInstr *I,
283                                   DebugLoc DL,
284                                   const MCInstrDesc &MCID) {
285  if (I->isInsideBundle()) {
286    MachineBasicBlock::instr_iterator MII = I;
287    return BuildMI(BB, MII, DL, MCID);
288  }
289
290  MachineBasicBlock::iterator MII = I;
291  return BuildMI(BB, MII, DL, MCID);
292}
293
294/// BuildMI - This version of the builder inserts the newly-built
295/// instruction at the end of the given MachineBasicBlock, and does NOT take a
296/// destination register.
297///
298inline MachineInstrBuilder BuildMI(MachineBasicBlock *BB,
299                                   DebugLoc DL,
300                                   const MCInstrDesc &MCID) {
301  return BuildMI(*BB, BB->end(), DL, MCID);
302}
303
304/// BuildMI - This version of the builder inserts the newly-built
305/// instruction at the end of the given MachineBasicBlock, and sets up the first
306/// operand as a destination virtual register.
307///
308inline MachineInstrBuilder BuildMI(MachineBasicBlock *BB,
309                                   DebugLoc DL,
310                                   const MCInstrDesc &MCID,
311                                   unsigned DestReg) {
312  return BuildMI(*BB, BB->end(), DL, MCID, DestReg);
313}
314
315inline unsigned getDefRegState(bool B) {
316  return B ? RegState::Define : 0;
317}
318inline unsigned getImplRegState(bool B) {
319  return B ? RegState::Implicit : 0;
320}
321inline unsigned getKillRegState(bool B) {
322  return B ? RegState::Kill : 0;
323}
324inline unsigned getDeadRegState(bool B) {
325  return B ? RegState::Dead : 0;
326}
327inline unsigned getUndefRegState(bool B) {
328  return B ? RegState::Undef : 0;
329}
330inline unsigned getInternalReadRegState(bool B) {
331  return B ? RegState::InternalRead : 0;
332}
333
334
335/// Helper class for constructing bundles of MachineInstrs.
336///
337/// MIBundleBuilder can create a bundle from scratch by inserting new
338/// MachineInstrs one at a time, or it can create a bundle from a sequence of
339/// existing MachineInstrs in a basic block.
340class MIBundleBuilder {
341  MachineBasicBlock &MBB;
342  MachineBasicBlock::instr_iterator Begin;
343  MachineBasicBlock::instr_iterator End;
344
345public:
346  /// Create an MIBundleBuilder that inserts instructions into a new bundle in
347  /// BB above the bundle or instruction at Pos.
348  MIBundleBuilder(MachineBasicBlock &BB,
349                  MachineBasicBlock::iterator Pos)
350    : MBB(BB), Begin(Pos.getInstrIterator()), End(Begin) {}
351
352  /// Create a bundle from the sequence of instructions between B and E.
353  MIBundleBuilder(MachineBasicBlock &BB,
354                  MachineBasicBlock::iterator B,
355                  MachineBasicBlock::iterator E)
356    : MBB(BB), Begin(B.getInstrIterator()), End(E.getInstrIterator()) {
357    assert(B != E && "No instructions to bundle");
358    ++B;
359    while (B != E) {
360      MachineInstr *MI = B;
361      ++B;
362      MI->bundleWithPred();
363    }
364  }
365
366  /// Create an MIBundleBuilder representing an existing instruction or bundle
367  /// that has MI as its head.
368  explicit MIBundleBuilder(MachineInstr *MI)
369    : MBB(*MI->getParent()), Begin(MI) {
370    MachineBasicBlock::iterator I = MI;
371    ++I;
372    End = I.getInstrIterator();
373  }
374
375  /// Return a reference to the basic block containing this bundle.
376  MachineBasicBlock &getMBB() const { return MBB; }
377
378  /// Return true if no instructions have been inserted in this bundle yet.
379  /// Empty bundles aren't representable in a MachineBasicBlock.
380  bool empty() const { return Begin == End; }
381
382  /// Return an iterator to the first bundled instruction.
383  MachineBasicBlock::instr_iterator begin() const { return Begin; }
384
385  /// Return an iterator beyond the last bundled instruction.
386  MachineBasicBlock::instr_iterator end() const { return End; }
387
388  /// Insert MI into this bundle before I which must point to an instruction in
389  /// the bundle, or end().
390  MIBundleBuilder &insert(MachineBasicBlock::instr_iterator I,
391                          MachineInstr *MI) {
392    MBB.insert(I, MI);
393    if (I == Begin) {
394      if (!empty())
395        MI->bundleWithSucc();
396      Begin = MI;
397      return *this;
398    }
399    if (I == End) {
400      MI->bundleWithPred();
401      return *this;
402    }
403    // MI was inserted in the middle of the bundle, so its neighbors' flags are
404    // already fine. Update MI's bundle flags manually.
405    MI->setFlag(MachineInstr::BundledPred);
406    MI->setFlag(MachineInstr::BundledSucc);
407    return *this;
408  }
409
410  /// Insert MI into MBB by prepending it to the instructions in the bundle.
411  /// MI will become the first instruction in the bundle.
412  MIBundleBuilder &prepend(MachineInstr *MI) {
413    return insert(begin(), MI);
414  }
415
416  /// Insert MI into MBB by appending it to the instructions in the bundle.
417  /// MI will become the last instruction in the bundle.
418  MIBundleBuilder &append(MachineInstr *MI) {
419    return insert(end(), MI);
420  }
421};
422
423} // End llvm namespace
424
425#endif
426