X86RegisterInfo.cpp revision 68bff8e15db12aa565818914cf7e452171f13e3a
1//===- X86RegisterInfo.cpp - X86 Register Information -----------*- C++ -*-===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file was developed by the LLVM research group and is distributed under
6// the University of Illinois Open Source License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file contains the X86 implementation of the MRegisterInfo class.  This
11// file is responsible for the frame pointer elimination optimization on X86.
12//
13//===----------------------------------------------------------------------===//
14
15#include "X86.h"
16#include "X86RegisterInfo.h"
17#include "X86InstrBuilder.h"
18#include "llvm/Constants.h"
19#include "llvm/Type.h"
20#include "llvm/CodeGen/ValueTypes.h"
21#include "llvm/CodeGen/MachineInstrBuilder.h"
22#include "llvm/CodeGen/MachineFunction.h"
23#include "llvm/CodeGen/MachineFrameInfo.h"
24#include "llvm/Target/TargetMachine.h"
25#include "llvm/Target/TargetFrameInfo.h"
26#include "Support/CommandLine.h"
27#include "Support/STLExtras.h"
28using namespace llvm;
29
30namespace {
31  cl::opt<bool>
32  NoFPElim("disable-fp-elim",
33	   cl::desc("Disable frame pointer elimination optimization"));
34  cl::opt<bool>
35  NoFusing("disable-spill-fusing",
36           cl::desc("Disable fusing of spill code into instructions"));
37  cl::opt<bool>
38  PrintFailedFusing("print-failed-fuse-candidates",
39                    cl::desc("Print instructions that the allocator wants to"
40                             " fuse, but the X86 backend currently can't"),
41                    cl::Hidden);
42}
43
44X86RegisterInfo::X86RegisterInfo()
45  : X86GenRegisterInfo(X86::ADJCALLSTACKDOWN, X86::ADJCALLSTACKUP) {}
46
47static unsigned getIdx(const TargetRegisterClass *RC) {
48  switch (RC->getSize()) {
49  default: assert(0 && "Invalid data size!");
50  case 1:  return 0;
51  case 2:  return 1;
52  case 4:  return 2;
53  case 10: return 3;
54  }
55}
56
57int X86RegisterInfo::storeRegToStackSlot(MachineBasicBlock &MBB,
58                                         MachineBasicBlock::iterator MI,
59                                         unsigned SrcReg, int FrameIdx,
60                                         const TargetRegisterClass *RC) const {
61  static const unsigned Opcode[] =
62    { X86::MOVmr8, X86::MOVmr16, X86::MOVmr32, X86::FSTPr80 };
63  MachineInstr *I = addFrameReference(BuildMI(Opcode[getIdx(RC)], 5),
64				       FrameIdx).addReg(SrcReg);
65  MBB.insert(MI, I);
66  return 1;
67}
68
69int X86RegisterInfo::loadRegFromStackSlot(MachineBasicBlock &MBB,
70                                          MachineBasicBlock::iterator MI,
71                                          unsigned DestReg, int FrameIdx,
72                                          const TargetRegisterClass *RC) const{
73  static const unsigned Opcode[] =
74    { X86::MOVrm8, X86::MOVrm16, X86::MOVrm32, X86::FLDr80 };
75  unsigned OC = Opcode[getIdx(RC)];
76  MBB.insert(MI, addFrameReference(BuildMI(OC, 4, DestReg), FrameIdx));
77  return 1;
78}
79
80int X86RegisterInfo::copyRegToReg(MachineBasicBlock &MBB,
81                                  MachineBasicBlock::iterator MI,
82                                  unsigned DestReg, unsigned SrcReg,
83                                  const TargetRegisterClass *RC) const {
84  static const unsigned Opcode[] =
85    { X86::MOVrr8, X86::MOVrr16, X86::MOVrr32, X86::FpMOV };
86  MBB.insert(MI, BuildMI(Opcode[getIdx(RC)],1,DestReg).addReg(SrcReg));
87  return 1;
88}
89
90static MachineInstr *MakeMInst(unsigned Opcode, unsigned FrameIndex,
91                               MachineInstr *MI) {
92  return addFrameReference(BuildMI(Opcode, 1, MI->getOperand(0).getReg()),
93                           FrameIndex);
94}
95
96static MachineInstr *MakeMRInst(unsigned Opcode, unsigned FrameIndex,
97                                MachineInstr *MI) {
98  return addFrameReference(BuildMI(Opcode, 5), FrameIndex)
99                 .addReg(MI->getOperand(1).getReg());
100}
101
102static MachineInstr *MakeMIInst(unsigned Opcode, unsigned FrameIndex,
103                                MachineInstr *MI) {
104  return addFrameReference(BuildMI(Opcode, 5), FrameIndex)
105                 .addZImm(MI->getOperand(1).getImmedValue());
106}
107
108static MachineInstr *MakeRMInst(unsigned Opcode, unsigned FrameIndex,
109                                MachineInstr *MI) {
110  return addFrameReference(BuildMI(Opcode, 5, MI->getOperand(0).getReg()),
111                           FrameIndex);
112}
113
114static MachineInstr *MakeRMIInst(unsigned Opcode, unsigned FrameIndex,
115                                 MachineInstr *MI) {
116  return addFrameReference(BuildMI(Opcode, 5, MI->getOperand(0).getReg()),
117                        FrameIndex).addZImm(MI->getOperand(2).getImmedValue());
118}
119
120
121bool X86RegisterInfo::foldMemoryOperand(MachineBasicBlock::iterator &MI,
122                                        unsigned i, int FrameIndex) const {
123  if (NoFusing) return false;
124
125  /// FIXME: This should obviously be autogenerated by tablegen when patterns
126  /// are available!
127  MachineBasicBlock& MBB = *MI->getParent();
128  MachineInstr* NI = 0;
129  if (i == 0) {
130    switch(MI->getOpcode()) {
131    case X86::MOVrr8:  NI = MakeMRInst(X86::MOVmr8 , FrameIndex, MI); break;
132    case X86::MOVrr16: NI = MakeMRInst(X86::MOVmr16, FrameIndex, MI); break;
133    case X86::MOVrr32: NI = MakeMRInst(X86::MOVmr32, FrameIndex, MI); break;
134    case X86::MOVri8:  NI = MakeMIInst(X86::MOVmi8 , FrameIndex, MI); break;
135    case X86::MOVri16: NI = MakeMIInst(X86::MOVmi16, FrameIndex, MI); break;
136    case X86::MOVri32: NI = MakeMIInst(X86::MOVmi32, FrameIndex, MI); break;
137    case X86::MULr8:   NI = MakeMInst(X86::MULm8 , FrameIndex, MI); break;
138    case X86::MULr16:  NI = MakeMInst(X86::MULm16, FrameIndex, MI); break;
139    case X86::MULr32:  NI = MakeMInst(X86::MULm32, FrameIndex, MI); break;
140    case X86::DIVr8:   NI = MakeMInst(X86::DIVm8 , FrameIndex, MI); break;
141    case X86::DIVr16:  NI = MakeMInst(X86::DIVm16, FrameIndex, MI); break;
142    case X86::DIVr32:  NI = MakeMInst(X86::DIVm32, FrameIndex, MI); break;
143    case X86::IDIVr8:  NI = MakeMInst(X86::IDIVm8 , FrameIndex, MI); break;
144    case X86::IDIVr16: NI = MakeMInst(X86::IDIVm16, FrameIndex, MI); break;
145    case X86::IDIVr32: NI = MakeMInst(X86::IDIVm32, FrameIndex, MI); break;
146    case X86::NEGr8:   NI = MakeMInst(X86::NEGm8 , FrameIndex, MI); break;
147    case X86::NEGr16:  NI = MakeMInst(X86::NEGm16, FrameIndex, MI); break;
148    case X86::NEGr32:  NI = MakeMInst(X86::NEGm32, FrameIndex, MI); break;
149    case X86::NOTr8:   NI = MakeMInst(X86::NOTm8 , FrameIndex, MI); break;
150    case X86::NOTr16:  NI = MakeMInst(X86::NOTm16, FrameIndex, MI); break;
151    case X86::NOTr32:  NI = MakeMInst(X86::NOTm32, FrameIndex, MI); break;
152    case X86::INCr8:   NI = MakeMInst(X86::INCm8 , FrameIndex, MI); break;
153    case X86::INCr16:  NI = MakeMInst(X86::INCm16, FrameIndex, MI); break;
154    case X86::INCr32:  NI = MakeMInst(X86::INCm32, FrameIndex, MI); break;
155    case X86::DECr8:   NI = MakeMInst(X86::DECm8 , FrameIndex, MI); break;
156    case X86::DECr16:  NI = MakeMInst(X86::DECm16, FrameIndex, MI); break;
157    case X86::DECr32:  NI = MakeMInst(X86::DECm32, FrameIndex, MI); break;
158    case X86::ADDrr8:  NI = MakeMRInst(X86::ADDmr8 , FrameIndex, MI); break;
159    case X86::ADDrr16: NI = MakeMRInst(X86::ADDmr16, FrameIndex, MI); break;
160    case X86::ADDrr32: NI = MakeMRInst(X86::ADDmr32, FrameIndex, MI); break;
161    case X86::ADCrr32: NI = MakeMRInst(X86::ADCmr32, FrameIndex, MI); break;
162    case X86::ADDri8:  NI = MakeMIInst(X86::ADDmi8 , FrameIndex, MI); break;
163    case X86::ADDri16: NI = MakeMIInst(X86::ADDmi16, FrameIndex, MI); break;
164    case X86::ADDri32: NI = MakeMIInst(X86::ADDmi32, FrameIndex, MI); break;
165    case X86::SUBrr8:  NI = MakeMRInst(X86::SUBmr8 , FrameIndex, MI); break;
166    case X86::SUBrr16: NI = MakeMRInst(X86::SUBmr16, FrameIndex, MI); break;
167    case X86::SUBrr32: NI = MakeMRInst(X86::SUBmr32, FrameIndex, MI); break;
168    case X86::SBBrr32: NI = MakeMRInst(X86::SBBmr32, FrameIndex, MI); break;
169    case X86::SUBri8:  NI = MakeMIInst(X86::SUBmi8 , FrameIndex, MI); break;
170    case X86::SUBri16: NI = MakeMIInst(X86::SUBmi16, FrameIndex, MI); break;
171    case X86::SUBri32: NI = MakeMIInst(X86::SUBmi32, FrameIndex, MI); break;
172    case X86::ANDrr8:  NI = MakeMRInst(X86::ANDmr8 , FrameIndex, MI); break;
173    case X86::ANDrr16: NI = MakeMRInst(X86::ANDmr16, FrameIndex, MI); break;
174    case X86::ANDrr32: NI = MakeMRInst(X86::ANDmr32, FrameIndex, MI); break;
175    case X86::ANDri8:  NI = MakeMIInst(X86::ANDmi8 , FrameIndex, MI); break;
176    case X86::ANDri16: NI = MakeMIInst(X86::ANDmi16, FrameIndex, MI); break;
177    case X86::ANDri32: NI = MakeMIInst(X86::ANDmi32, FrameIndex, MI); break;
178    case X86::ORrr8:   NI = MakeMRInst(X86::ORmr8 ,  FrameIndex, MI); break;
179    case X86::ORrr16:  NI = MakeMRInst(X86::ORmr16,  FrameIndex, MI); break;
180    case X86::ORrr32:  NI = MakeMRInst(X86::ORmr32,  FrameIndex, MI); break;
181    case X86::ORri8:   NI = MakeMIInst(X86::ORmi8 ,  FrameIndex, MI); break;
182    case X86::ORri16:  NI = MakeMIInst(X86::ORmi16,  FrameIndex, MI); break;
183    case X86::ORri32:  NI = MakeMIInst(X86::ORmi32,  FrameIndex, MI); break;
184    case X86::XORrr8:  NI = MakeMRInst(X86::XORmr8 , FrameIndex, MI); break;
185    case X86::XORrr16: NI = MakeMRInst(X86::XORmr16, FrameIndex, MI); break;
186    case X86::XORrr32: NI = MakeMRInst(X86::XORmr32, FrameIndex, MI); break;
187    case X86::XORri8:  NI = MakeMIInst(X86::XORmi8 , FrameIndex, MI); break;
188    case X86::XORri16: NI = MakeMIInst(X86::XORmi16, FrameIndex, MI); break;
189    case X86::XORri32: NI = MakeMIInst(X86::XORmi32, FrameIndex, MI); break;
190    case X86::CMPrr8:  NI = MakeMRInst(X86::CMPmr8 , FrameIndex, MI); break;
191    case X86::CMPrr16: NI = MakeMRInst(X86::CMPmr16, FrameIndex, MI); break;
192    case X86::CMPrr32: NI = MakeMRInst(X86::CMPmr32, FrameIndex, MI); break;
193    case X86::CMPri8:  NI = MakeMIInst(X86::CMPmi8 , FrameIndex, MI); break;
194    case X86::CMPri16: NI = MakeMIInst(X86::CMPmi16, FrameIndex, MI); break;
195    case X86::CMPri32: NI = MakeMIInst(X86::CMPmi32, FrameIndex, MI); break;
196    default: break; // Cannot fold
197    }
198  } else if (i == 1) {
199    switch(MI->getOpcode()) {
200    case X86::MOVrr8:  NI = MakeRMInst(X86::MOVrm8 , FrameIndex, MI); break;
201    case X86::MOVrr16: NI = MakeRMInst(X86::MOVrm16, FrameIndex, MI); break;
202    case X86::MOVrr32: NI = MakeRMInst(X86::MOVrm32, FrameIndex, MI); break;
203    case X86::ADDrr8:  NI = MakeRMInst(X86::ADDrm8 , FrameIndex, MI); break;
204    case X86::ADDrr16: NI = MakeRMInst(X86::ADDrm16, FrameIndex, MI); break;
205    case X86::ADDrr32: NI = MakeRMInst(X86::ADDrm32, FrameIndex, MI); break;
206    case X86::ADCrr32: NI = MakeRMInst(X86::ADCrm32, FrameIndex, MI); break;
207    case X86::SUBrr8:  NI = MakeRMInst(X86::SUBrm8 , FrameIndex, MI); break;
208    case X86::SUBrr16: NI = MakeRMInst(X86::SUBrm16, FrameIndex, MI); break;
209    case X86::SUBrr32: NI = MakeRMInst(X86::SUBrm32, FrameIndex, MI); break;
210    case X86::SBBrr32: NI = MakeRMInst(X86::SBBrm32, FrameIndex, MI); break;
211    case X86::ANDrr8:  NI = MakeRMInst(X86::ANDrm8 , FrameIndex, MI); break;
212    case X86::ANDrr16: NI = MakeRMInst(X86::ANDrm16, FrameIndex, MI); break;
213    case X86::ANDrr32: NI = MakeRMInst(X86::ANDrm32, FrameIndex, MI); break;
214    case X86::ORrr8:   NI = MakeRMInst(X86::ORrm8 ,  FrameIndex, MI); break;
215    case X86::ORrr16:  NI = MakeRMInst(X86::ORrm16,  FrameIndex, MI); break;
216    case X86::ORrr32:  NI = MakeRMInst(X86::ORrm32,  FrameIndex, MI); break;
217    case X86::XORrr8:  NI = MakeRMInst(X86::XORrm8 , FrameIndex, MI); break;
218    case X86::XORrr16: NI = MakeRMInst(X86::XORrm16, FrameIndex, MI); break;
219    case X86::XORrr32: NI = MakeRMInst(X86::XORrm32, FrameIndex, MI); break;
220    case X86::IMULrr16:NI = MakeRMInst(X86::IMULrm16, FrameIndex, MI); break;
221    case X86::IMULrr32:NI = MakeRMInst(X86::IMULrm32, FrameIndex, MI); break;
222    case X86::IMULrri16: NI = MakeRMIInst(X86::IMULrmi16, FrameIndex, MI);break;
223    case X86::IMULrri32: NI = MakeRMIInst(X86::IMULrmi32, FrameIndex, MI);break;
224    case X86::CMPrr8:  NI = MakeRMInst(X86::CMPrm8 , FrameIndex, MI); break;
225    case X86::CMPrr16: NI = MakeRMInst(X86::CMPrm16, FrameIndex, MI); break;
226    case X86::CMPrr32: NI = MakeRMInst(X86::CMPrm32, FrameIndex, MI); break;
227
228    case X86::MOVSXr16r8: NI = MakeRMInst(X86::MOVSXr16m8 , FrameIndex, MI); break;
229    case X86::MOVSXr32r8: NI = MakeRMInst(X86::MOVSXr32m8, FrameIndex, MI); break;
230    case X86::MOVSXr32r16:NI = MakeRMInst(X86::MOVSXr32m16, FrameIndex, MI); break;
231    case X86::MOVZXr16r8: NI = MakeRMInst(X86::MOVZXr16m8 , FrameIndex, MI); break;
232    case X86::MOVZXr32r8: NI = MakeRMInst(X86::MOVZXr32m8, FrameIndex, MI); break;
233    case X86::MOVZXr32r16:NI = MakeRMInst(X86::MOVZXr32m16, FrameIndex, MI); break;
234    default: break;
235    }
236  }
237  if (NI) {
238    MI = MBB.insert(MBB.erase(MI), NI);
239    return true;
240  } else {
241    if (PrintFailedFusing)
242      std::cerr << "We failed to fuse: " << *MI;
243    return false;
244  }
245}
246
247//===----------------------------------------------------------------------===//
248// Stack Frame Processing methods
249//===----------------------------------------------------------------------===//
250
251// hasFP - Return true if the specified function should have a dedicated frame
252// pointer register.  This is true if the function has variable sized allocas or
253// if frame pointer elimination is disabled.
254//
255static bool hasFP(MachineFunction &MF) {
256  return NoFPElim || MF.getFrameInfo()->hasVarSizedObjects();
257}
258
259void X86RegisterInfo::
260eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
261                              MachineBasicBlock::iterator I) const {
262  if (hasFP(MF)) {
263    // If we have a frame pointer, turn the adjcallstackup instruction into a
264    // 'sub ESP, <amt>' and the adjcallstackdown instruction into 'add ESP,
265    // <amt>'
266    MachineInstr *Old = I;
267    unsigned Amount = Old->getOperand(0).getImmedValue();
268    if (Amount != 0) {
269      // We need to keep the stack aligned properly.  To do this, we round the
270      // amount of space needed for the outgoing arguments up to the next
271      // alignment boundary.
272      unsigned Align = MF.getTarget().getFrameInfo().getStackAlignment();
273      Amount = (Amount+Align-1)/Align*Align;
274
275      MachineInstr *New;
276      if (Old->getOpcode() == X86::ADJCALLSTACKDOWN) {
277	New=BuildMI(X86::SUBri32, 1, X86::ESP, MOTy::UseAndDef).addZImm(Amount);
278      } else {
279	assert(Old->getOpcode() == X86::ADJCALLSTACKUP);
280	New=BuildMI(X86::ADDri32, 1, X86::ESP, MOTy::UseAndDef).addZImm(Amount);
281      }
282
283      // Replace the pseudo instruction with a new instruction...
284      MBB.insert(I, New);
285    }
286  }
287
288  MBB.erase(I);
289}
290
291void X86RegisterInfo::eliminateFrameIndex(MachineFunction &MF,
292                                         MachineBasicBlock::iterator II) const {
293  unsigned i = 0;
294  MachineInstr &MI = *II;
295  while (!MI.getOperand(i).isFrameIndex()) {
296    ++i;
297    assert(i < MI.getNumOperands() && "Instr doesn't have FrameIndex operand!");
298  }
299
300  int FrameIndex = MI.getOperand(i).getFrameIndex();
301
302  // This must be part of a four operand memory reference.  Replace the
303  // FrameIndex with base register with EBP.  Add add an offset to the offset.
304  MI.SetMachineOperandReg(i, hasFP(MF) ? X86::EBP : X86::ESP);
305
306  // Now add the frame object offset to the offset from EBP.
307  int Offset = MF.getFrameInfo()->getObjectOffset(FrameIndex) +
308               MI.getOperand(i+3).getImmedValue()+4;
309
310  if (!hasFP(MF))
311    Offset += MF.getFrameInfo()->getStackSize();
312  else
313    Offset += 4;  // Skip the saved EBP
314
315  MI.SetMachineOperandConst(i+3, MachineOperand::MO_SignExtendedImmed, Offset);
316}
317
318void
319X86RegisterInfo::processFunctionBeforeFrameFinalized(MachineFunction &MF) const{
320  if (hasFP(MF)) {
321    // Create a frame entry for the EBP register that must be saved.
322    int FrameIdx = MF.getFrameInfo()->CreateFixedObject(4, -8);
323    assert(FrameIdx == MF.getFrameInfo()->getObjectIndexBegin() &&
324           "Slot for EBP register must be last in order to be found!");
325  }
326}
327
328void X86RegisterInfo::emitPrologue(MachineFunction &MF) const {
329  MachineBasicBlock &MBB = MF.front();   // Prolog goes in entry BB
330  MachineBasicBlock::iterator MBBI = MBB.begin();
331  MachineFrameInfo *MFI = MF.getFrameInfo();
332  MachineInstr *MI;
333
334  // Get the number of bytes to allocate from the FrameInfo
335  unsigned NumBytes = MFI->getStackSize();
336  if (hasFP(MF)) {
337    // Get the offset of the stack slot for the EBP register... which is
338    // guaranteed to be the last slot by processFunctionBeforeFrameFinalized.
339    int EBPOffset = MFI->getObjectOffset(MFI->getObjectIndexBegin())+4;
340
341    if (NumBytes) {   // adjust stack pointer: ESP -= numbytes
342      MI= BuildMI(X86::SUBri32, 1, X86::ESP, MOTy::UseAndDef).addZImm(NumBytes);
343      MBB.insert(MBBI, MI);
344    }
345
346    // Save EBP into the appropriate stack slot...
347    MI = addRegOffset(BuildMI(X86::MOVmr32, 5),    // mov [ESP-<offset>], EBP
348		      X86::ESP, EBPOffset+NumBytes).addReg(X86::EBP);
349    MBB.insert(MBBI, MI);
350
351    // Update EBP with the new base value...
352    if (NumBytes == 4)    // mov EBP, ESP
353      MI = BuildMI(X86::MOVrr32, 2, X86::EBP).addReg(X86::ESP);
354    else                  // lea EBP, [ESP+StackSize]
355      MI = addRegOffset(BuildMI(X86::LEAr32, 5, X86::EBP), X86::ESP,NumBytes-4);
356
357    MBB.insert(MBBI, MI);
358
359  } else {
360    if (MFI->hasCalls()) {
361      // When we have no frame pointer, we reserve argument space for call sites
362      // in the function immediately on entry to the current function.  This
363      // eliminates the need for add/sub ESP brackets around call sites.
364      //
365      NumBytes += MFI->getMaxCallFrameSize();
366
367      // Round the size to a multiple of the alignment (don't forget the 4 byte
368      // offset though).
369      unsigned Align = MF.getTarget().getFrameInfo().getStackAlignment();
370      NumBytes = ((NumBytes+4)+Align-1)/Align*Align - 4;
371    }
372
373    // Update frame info to pretend that this is part of the stack...
374    MFI->setStackSize(NumBytes);
375
376    if (NumBytes) {
377      // adjust stack pointer: ESP -= numbytes
378      MI= BuildMI(X86::SUBri32, 1, X86::ESP, MOTy::UseAndDef).addZImm(NumBytes);
379      MBB.insert(MBBI, MI);
380    }
381  }
382}
383
384void X86RegisterInfo::emitEpilogue(MachineFunction &MF,
385                                   MachineBasicBlock &MBB) const {
386  const MachineFrameInfo *MFI = MF.getFrameInfo();
387  MachineBasicBlock::iterator MBBI = prior(MBB.end());
388  MachineInstr *MI;
389  assert(MBBI->getOpcode() == X86::RET &&
390         "Can only insert epilog into returning blocks");
391
392  if (hasFP(MF)) {
393    // Get the offset of the stack slot for the EBP register... which is
394    // guaranteed to be the last slot by processFunctionBeforeFrameFinalized.
395    int EBPOffset = MFI->getObjectOffset(MFI->getObjectIndexEnd()-1)+4;
396
397    // mov ESP, EBP
398    MI = BuildMI(X86::MOVrr32, 1,X86::ESP).addReg(X86::EBP);
399    MBB.insert(MBBI, MI);
400
401    // pop EBP
402    MI = BuildMI(X86::POPr32, 0, X86::EBP);
403    MBB.insert(MBBI, MI);
404  } else {
405    // Get the number of bytes allocated from the FrameInfo...
406    unsigned NumBytes = MFI->getStackSize();
407
408    if (NumBytes) {    // adjust stack pointer back: ESP += numbytes
409      MI =BuildMI(X86::ADDri32, 1, X86::ESP, MOTy::UseAndDef).addZImm(NumBytes);
410      MBB.insert(MBBI, MI);
411    }
412  }
413}
414
415#include "X86GenRegisterInfo.inc"
416
417const TargetRegisterClass*
418X86RegisterInfo::getRegClassForType(const Type* Ty) const {
419  switch (Ty->getPrimitiveID()) {
420  case Type::LongTyID:
421  case Type::ULongTyID: assert(0 && "Long values can't fit in registers!");
422  default:              assert(0 && "Invalid type to getClass!");
423  case Type::BoolTyID:
424  case Type::SByteTyID:
425  case Type::UByteTyID:   return &R8Instance;
426  case Type::ShortTyID:
427  case Type::UShortTyID:  return &R16Instance;
428  case Type::IntTyID:
429  case Type::UIntTyID:
430  case Type::PointerTyID: return &R32Instance;
431
432  case Type::FloatTyID:
433  case Type::DoubleTyID: return &RFPInstance;
434  }
435}
436