X86RegisterInfo.cpp revision f8be5e94aaf70d53dc043f5e541fc0bf6771db22
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/TargetFrameInfo.h"
25#include "llvm/Target/TargetMachine.h"
26#include "llvm/Target/TargetOptions.h"
27#include "Support/CommandLine.h"
28#include "Support/STLExtras.h"
29#include <iostream>
30
31using namespace llvm;
32
33namespace {
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::MOV8mr, X86::MOV16mr, X86::MOV32mr, X86::FSTP80m };
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::MOV8rm, X86::MOV16rm, X86::MOV32rm, X86::FLD80m };
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::MOV8rr, X86::MOV16rr, X86::MOV32rr, 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, 4), FrameIndex);
93}
94
95static MachineInstr *MakeMRInst(unsigned Opcode, unsigned FrameIndex,
96                                MachineInstr *MI) {
97  return addFrameReference(BuildMI(Opcode, 5), FrameIndex)
98                 .addReg(MI->getOperand(1).getReg());
99}
100
101static MachineInstr *MakeMRIInst(unsigned Opcode, unsigned FrameIndex,
102                                 MachineInstr *MI) {
103  return addFrameReference(BuildMI(Opcode, 6), FrameIndex)
104      .addReg(MI->getOperand(1).getReg())
105      .addZImm(MI->getOperand(2).getImmedValue());
106}
107
108static MachineInstr *MakeMIInst(unsigned Opcode, unsigned FrameIndex,
109                                MachineInstr *MI) {
110  if (MI->getOperand(1).isImmediate())
111    return addFrameReference(BuildMI(Opcode, 5), FrameIndex)
112      .addZImm(MI->getOperand(1).getImmedValue());
113  else if (MI->getOperand(1).isGlobalAddress())
114    return addFrameReference(BuildMI(Opcode, 5), FrameIndex)
115      .addGlobalAddress(MI->getOperand(1).getGlobal());
116  assert(0 && "Unknown operand for MakeMI!");
117  return 0;
118}
119
120static MachineInstr *MakeRMInst(unsigned Opcode, unsigned FrameIndex,
121                                MachineInstr *MI) {
122  const MachineOperand& op = MI->getOperand(0);
123  return addFrameReference(BuildMI(Opcode, 5, op.getReg(), op.getUseType()),
124                           FrameIndex);
125}
126
127static MachineInstr *MakeRMIInst(unsigned Opcode, unsigned FrameIndex,
128                                 MachineInstr *MI) {
129  const MachineOperand& op = MI->getOperand(0);
130  return addFrameReference(BuildMI(Opcode, 6, op.getReg(), op.getUseType()),
131                        FrameIndex).addZImm(MI->getOperand(2).getImmedValue());
132}
133
134
135MachineInstr* X86RegisterInfo::foldMemoryOperand(MachineInstr* MI,
136                                                 unsigned i,
137                                                 int FrameIndex) const {
138  if (NoFusing) return NULL;
139
140  /// FIXME: This should obviously be autogenerated by tablegen when patterns
141  /// are available!
142  MachineBasicBlock& MBB = *MI->getParent();
143  if (i == 0) {
144    switch(MI->getOpcode()) {
145    case X86::XCHG8rr:   return MakeMRInst(X86::XCHG8mr ,FrameIndex, MI);
146    case X86::XCHG16rr:  return MakeMRInst(X86::XCHG16mr,FrameIndex, MI);
147    case X86::XCHG32rr:  return MakeMRInst(X86::XCHG32mr,FrameIndex, MI);
148    case X86::MOV8rr:    return MakeMRInst(X86::MOV8mr , FrameIndex, MI);
149    case X86::MOV16rr:   return MakeMRInst(X86::MOV16mr, FrameIndex, MI);
150    case X86::MOV32rr:   return MakeMRInst(X86::MOV32mr, FrameIndex, MI);
151    case X86::MOV8ri:    return MakeMIInst(X86::MOV8mi , FrameIndex, MI);
152    case X86::MOV16ri:   return MakeMIInst(X86::MOV16mi, FrameIndex, MI);
153    case X86::MOV32ri:   return MakeMIInst(X86::MOV32mi, FrameIndex, MI);
154    case X86::MUL8r:     return MakeMInst( X86::MUL8m ,  FrameIndex, MI);
155    case X86::MUL16r:    return MakeMInst( X86::MUL16m,  FrameIndex, MI);
156    case X86::MUL32r:    return MakeMInst( X86::MUL32m,  FrameIndex, MI);
157    case X86::DIV8r:     return MakeMInst( X86::DIV8m ,  FrameIndex, MI);
158    case X86::DIV16r:    return MakeMInst( X86::DIV16m,  FrameIndex, MI);
159    case X86::DIV32r:    return MakeMInst( X86::DIV32m,  FrameIndex, MI);
160    case X86::IDIV8r:    return MakeMInst( X86::IDIV8m , FrameIndex, MI);
161    case X86::IDIV16r:   return MakeMInst( X86::IDIV16m, FrameIndex, MI);
162    case X86::IDIV32r:   return MakeMInst( X86::IDIV32m, FrameIndex, MI);
163    case X86::NEG8r:     return MakeMInst( X86::NEG8m ,  FrameIndex, MI);
164    case X86::NEG16r:    return MakeMInst( X86::NEG16m,  FrameIndex, MI);
165    case X86::NEG32r:    return MakeMInst( X86::NEG32m,  FrameIndex, MI);
166    case X86::NOT8r:     return MakeMInst( X86::NOT8m ,  FrameIndex, MI);
167    case X86::NOT16r:    return MakeMInst( X86::NOT16m,  FrameIndex, MI);
168    case X86::NOT32r:    return MakeMInst( X86::NOT32m,  FrameIndex, MI);
169    case X86::INC8r:     return MakeMInst( X86::INC8m ,  FrameIndex, MI);
170    case X86::INC16r:    return MakeMInst( X86::INC16m,  FrameIndex, MI);
171    case X86::INC32r:    return MakeMInst( X86::INC32m,  FrameIndex, MI);
172    case X86::DEC8r:     return MakeMInst( X86::DEC8m ,  FrameIndex, MI);
173    case X86::DEC16r:    return MakeMInst( X86::DEC16m,  FrameIndex, MI);
174    case X86::DEC32r:    return MakeMInst( X86::DEC32m,  FrameIndex, MI);
175    case X86::ADD8rr:    return MakeMRInst(X86::ADD8mr , FrameIndex, MI);
176    case X86::ADD16rr:   return MakeMRInst(X86::ADD16mr, FrameIndex, MI);
177    case X86::ADD32rr:   return MakeMRInst(X86::ADD32mr, FrameIndex, MI);
178    case X86::ADC32rr:   return MakeMRInst(X86::ADC32mr, FrameIndex, MI);
179    case X86::ADC32ri:   return MakeMIInst(X86::ADC32mi, FrameIndex, MI);
180    case X86::ADD8ri:    return MakeMIInst(X86::ADD8mi , FrameIndex, MI);
181    case X86::ADD16ri:   return MakeMIInst(X86::ADD16mi, FrameIndex, MI);
182    case X86::ADD32ri:   return MakeMIInst(X86::ADD32mi, FrameIndex, MI);
183    case X86::SUB8rr:    return MakeMRInst(X86::SUB8mr , FrameIndex, MI);
184    case X86::SUB16rr:   return MakeMRInst(X86::SUB16mr, FrameIndex, MI);
185    case X86::SUB32rr:   return MakeMRInst(X86::SUB32mr, FrameIndex, MI);
186    case X86::SBB32rr:   return MakeMRInst(X86::SBB32mr, FrameIndex, MI);
187    case X86::SBB32ri:   return MakeMIInst(X86::SBB32mi, FrameIndex, MI);
188    case X86::SUB8ri:    return MakeMIInst(X86::SUB8mi , FrameIndex, MI);
189    case X86::SUB16ri:   return MakeMIInst(X86::SUB16mi, FrameIndex, MI);
190    case X86::SUB32ri:   return MakeMIInst(X86::SUB32mi, FrameIndex, MI);
191    case X86::AND8rr:    return MakeMRInst(X86::AND8mr , FrameIndex, MI);
192    case X86::AND16rr:   return MakeMRInst(X86::AND16mr, FrameIndex, MI);
193    case X86::AND32rr:   return MakeMRInst(X86::AND32mr, FrameIndex, MI);
194    case X86::AND8ri:    return MakeMIInst(X86::AND8mi , FrameIndex, MI);
195    case X86::AND16ri:   return MakeMIInst(X86::AND16mi, FrameIndex, MI);
196    case X86::AND32ri:   return MakeMIInst(X86::AND32mi, FrameIndex, MI);
197    case X86::OR8rr:     return MakeMRInst(X86::OR8mr ,  FrameIndex, MI);
198    case X86::OR16rr:    return MakeMRInst(X86::OR16mr,  FrameIndex, MI);
199    case X86::OR32rr:    return MakeMRInst(X86::OR32mr,  FrameIndex, MI);
200    case X86::OR8ri:     return MakeMIInst(X86::OR8mi ,  FrameIndex, MI);
201    case X86::OR16ri:    return MakeMIInst(X86::OR16mi,  FrameIndex, MI);
202    case X86::OR32ri:    return MakeMIInst(X86::OR32mi,  FrameIndex, MI);
203    case X86::XOR8rr:    return MakeMRInst(X86::XOR8mr , FrameIndex, MI);
204    case X86::XOR16rr:   return MakeMRInst(X86::XOR16mr, FrameIndex, MI);
205    case X86::XOR32rr:   return MakeMRInst(X86::XOR32mr, FrameIndex, MI);
206    case X86::XOR8ri:    return MakeMIInst(X86::XOR8mi , FrameIndex, MI);
207    case X86::XOR16ri:   return MakeMIInst(X86::XOR16mi, FrameIndex, MI);
208    case X86::XOR32ri:   return MakeMIInst(X86::XOR32mi, FrameIndex, MI);
209    case X86::SHL8rCL:   return MakeMInst( X86::SHL8mCL ,FrameIndex, MI);
210    case X86::SHL16rCL:  return MakeMInst( X86::SHL16mCL,FrameIndex, MI);
211    case X86::SHL32rCL:  return MakeMInst( X86::SHL32mCL,FrameIndex, MI);
212    case X86::SHL8ri:    return MakeMIInst(X86::SHL8mi , FrameIndex, MI);
213    case X86::SHL16ri:   return MakeMIInst(X86::SHL16mi, FrameIndex, MI);
214    case X86::SHL32ri:   return MakeMIInst(X86::SHL32mi, FrameIndex, MI);
215    case X86::SHR8rCL:   return MakeMInst( X86::SHR8mCL ,FrameIndex, MI);
216    case X86::SHR16rCL:  return MakeMInst( X86::SHR16mCL,FrameIndex, MI);
217    case X86::SHR32rCL:  return MakeMInst( X86::SHR32mCL,FrameIndex, MI);
218    case X86::SHR8ri:    return MakeMIInst(X86::SHR8mi , FrameIndex, MI);
219    case X86::SHR16ri:   return MakeMIInst(X86::SHR16mi, FrameIndex, MI);
220    case X86::SHR32ri:   return MakeMIInst(X86::SHR32mi, FrameIndex, MI);
221    case X86::SAR8rCL:   return MakeMInst( X86::SAR8mCL ,FrameIndex, MI);
222    case X86::SAR16rCL:  return MakeMInst( X86::SAR16mCL,FrameIndex, MI);
223    case X86::SAR32rCL:  return MakeMInst( X86::SAR32mCL,FrameIndex, MI);
224    case X86::SAR8ri:    return MakeMIInst(X86::SAR8mi , FrameIndex, MI);
225    case X86::SAR16ri:   return MakeMIInst(X86::SAR16mi, FrameIndex, MI);
226    case X86::SAR32ri:   return MakeMIInst(X86::SAR32mi, FrameIndex, MI);
227    case X86::SHLD32rrCL:return MakeMRInst( X86::SHLD32mrCL,FrameIndex, MI);
228    case X86::SHLD32rri8:return MakeMRIInst(X86::SHLD32mri8,FrameIndex, MI);
229    case X86::SHRD32rrCL:return MakeMRInst( X86::SHRD32mrCL,FrameIndex, MI);
230    case X86::SHRD32rri8:return MakeMRIInst(X86::SHRD32mri8,FrameIndex, MI);
231    case X86::SETBr:     return MakeMInst( X86::SETBm,   FrameIndex, MI);
232    case X86::SETAEr:    return MakeMInst( X86::SETAEm,  FrameIndex, MI);
233    case X86::SETEr:     return MakeMInst( X86::SETEm,   FrameIndex, MI);
234    case X86::SETNEr:    return MakeMInst( X86::SETNEm,  FrameIndex, MI);
235    case X86::SETBEr:    return MakeMInst( X86::SETBEm,  FrameIndex, MI);
236    case X86::SETAr:     return MakeMInst( X86::SETAm,   FrameIndex, MI);
237    case X86::SETSr:     return MakeMInst( X86::SETSm,   FrameIndex, MI);
238    case X86::SETNSr:    return MakeMInst( X86::SETNSm,  FrameIndex, MI);
239    case X86::SETPr:     return MakeMInst( X86::SETPm,   FrameIndex, MI);
240    case X86::SETLr:     return MakeMInst( X86::SETLm,   FrameIndex, MI);
241    case X86::SETGEr:    return MakeMInst( X86::SETGEm,  FrameIndex, MI);
242    case X86::SETLEr:    return MakeMInst( X86::SETLEm,  FrameIndex, MI);
243    case X86::SETGr:     return MakeMInst( X86::SETGm,   FrameIndex, MI);
244    case X86::TEST8rr:   return MakeMRInst(X86::TEST8mr ,FrameIndex, MI);
245    case X86::TEST16rr:  return MakeMRInst(X86::TEST16mr,FrameIndex, MI);
246    case X86::TEST32rr:  return MakeMRInst(X86::TEST32mr,FrameIndex, MI);
247    case X86::TEST8ri:   return MakeMIInst(X86::TEST8mi ,FrameIndex, MI);
248    case X86::TEST16ri:  return MakeMIInst(X86::TEST16mi,FrameIndex, MI);
249    case X86::TEST32ri:  return MakeMIInst(X86::TEST32mi,FrameIndex, MI);
250    case X86::CMP8rr:    return MakeMRInst(X86::CMP8mr , FrameIndex, MI);
251    case X86::CMP16rr:   return MakeMRInst(X86::CMP16mr, FrameIndex, MI);
252    case X86::CMP32rr:   return MakeMRInst(X86::CMP32mr, FrameIndex, MI);
253    case X86::CMP8ri:    return MakeMIInst(X86::CMP8mi , FrameIndex, MI);
254    case X86::CMP16ri:   return MakeMIInst(X86::CMP16mi, FrameIndex, MI);
255    case X86::CMP32ri:   return MakeMIInst(X86::CMP32mi, FrameIndex, MI);
256    }
257  } else if (i == 1) {
258    switch(MI->getOpcode()) {
259    case X86::XCHG8rr:   return MakeRMInst(X86::XCHG8rm ,FrameIndex, MI);
260    case X86::XCHG16rr:  return MakeRMInst(X86::XCHG16rm,FrameIndex, MI);
261    case X86::XCHG32rr:  return MakeRMInst(X86::XCHG32rm,FrameIndex, MI);
262    case X86::MOV8rr:    return MakeRMInst(X86::MOV8rm , FrameIndex, MI);
263    case X86::MOV16rr:   return MakeRMInst(X86::MOV16rm, FrameIndex, MI);
264    case X86::MOV32rr:   return MakeRMInst(X86::MOV32rm, FrameIndex, MI);
265    case X86::CMOVB16rr: return MakeRMInst(X86::CMOVB16rm , FrameIndex, MI);
266    case X86::CMOVB32rr: return MakeRMInst(X86::CMOVB32rm , FrameIndex, MI);
267    case X86::CMOVAE16rr: return MakeRMInst(X86::CMOVAE16rm , FrameIndex, MI);
268    case X86::CMOVAE32rr: return MakeRMInst(X86::CMOVAE32rm , FrameIndex, MI);
269    case X86::CMOVE16rr: return MakeRMInst(X86::CMOVE16rm , FrameIndex, MI);
270    case X86::CMOVE32rr: return MakeRMInst(X86::CMOVE32rm , FrameIndex, MI);
271    case X86::CMOVNE16rr:return MakeRMInst(X86::CMOVNE16rm, FrameIndex, MI);
272    case X86::CMOVNE32rr:return MakeRMInst(X86::CMOVNE32rm, FrameIndex, MI);
273    case X86::CMOVBE16rr:return MakeRMInst(X86::CMOVBE16rm, FrameIndex, MI);
274    case X86::CMOVBE32rr:return MakeRMInst(X86::CMOVBE32rm, FrameIndex, MI);
275    case X86::CMOVA16rr:return MakeRMInst(X86::CMOVA16rm, FrameIndex, MI);
276    case X86::CMOVA32rr:return MakeRMInst(X86::CMOVA32rm, FrameIndex, MI);
277    case X86::CMOVS16rr: return MakeRMInst(X86::CMOVS16rm , FrameIndex, MI);
278    case X86::CMOVS32rr: return MakeRMInst(X86::CMOVS32rm , FrameIndex, MI);
279    case X86::CMOVNS16rr: return MakeRMInst(X86::CMOVNS16rm , FrameIndex, MI);
280    case X86::CMOVNS32rr: return MakeRMInst(X86::CMOVNS32rm , FrameIndex, MI);
281    case X86::CMOVL16rr: return MakeRMInst(X86::CMOVL16rm , FrameIndex, MI);
282    case X86::CMOVL32rr: return MakeRMInst(X86::CMOVL32rm , FrameIndex, MI);
283    case X86::CMOVGE16rr: return MakeRMInst(X86::CMOVGE16rm , FrameIndex, MI);
284    case X86::CMOVGE32rr: return MakeRMInst(X86::CMOVGE32rm , FrameIndex, MI);
285    case X86::CMOVLE16rr: return MakeRMInst(X86::CMOVLE16rm , FrameIndex, MI);
286    case X86::CMOVLE32rr: return MakeRMInst(X86::CMOVLE32rm , FrameIndex, MI);
287    case X86::CMOVG16rr: return MakeRMInst(X86::CMOVG16rm , FrameIndex, MI);
288    case X86::CMOVG32rr: return MakeRMInst(X86::CMOVG32rm , FrameIndex, MI);
289    case X86::ADD8rr:    return MakeRMInst(X86::ADD8rm , FrameIndex, MI);
290    case X86::ADD16rr:   return MakeRMInst(X86::ADD16rm, FrameIndex, MI);
291    case X86::ADD32rr:   return MakeRMInst(X86::ADD32rm, FrameIndex, MI);
292    case X86::ADC32rr:   return MakeRMInst(X86::ADC32rm, FrameIndex, MI);
293    case X86::SUB8rr:    return MakeRMInst(X86::SUB8rm , FrameIndex, MI);
294    case X86::SUB16rr:   return MakeRMInst(X86::SUB16rm, FrameIndex, MI);
295    case X86::SUB32rr:   return MakeRMInst(X86::SUB32rm, FrameIndex, MI);
296    case X86::SBB32rr:   return MakeRMInst(X86::SBB32rm, FrameIndex, MI);
297    case X86::AND8rr:    return MakeRMInst(X86::AND8rm , FrameIndex, MI);
298    case X86::AND16rr:   return MakeRMInst(X86::AND16rm, FrameIndex, MI);
299    case X86::AND32rr:   return MakeRMInst(X86::AND32rm, FrameIndex, MI);
300    case X86::OR8rr:     return MakeRMInst(X86::OR8rm ,  FrameIndex, MI);
301    case X86::OR16rr:    return MakeRMInst(X86::OR16rm,  FrameIndex, MI);
302    case X86::OR32rr:    return MakeRMInst(X86::OR32rm,  FrameIndex, MI);
303    case X86::XOR8rr:    return MakeRMInst(X86::XOR8rm , FrameIndex, MI);
304    case X86::XOR16rr:   return MakeRMInst(X86::XOR16rm, FrameIndex, MI);
305    case X86::XOR32rr:   return MakeRMInst(X86::XOR32rm, FrameIndex, MI);
306    case X86::TEST8rr:   return MakeRMInst(X86::TEST8rm ,FrameIndex, MI);
307    case X86::TEST16rr:  return MakeRMInst(X86::TEST16rm,FrameIndex, MI);
308    case X86::TEST32rr:  return MakeRMInst(X86::TEST32rm,FrameIndex, MI);
309    case X86::IMUL16rr:  return MakeRMInst(X86::IMUL16rm,FrameIndex, MI);
310    case X86::IMUL32rr:  return MakeRMInst(X86::IMUL32rm,FrameIndex, MI);
311    case X86::IMUL16rri: return MakeRMIInst(X86::IMUL16rmi, FrameIndex, MI);
312    case X86::IMUL32rri: return MakeRMIInst(X86::IMUL32rmi, FrameIndex, MI);
313    case X86::CMP8rr:    return MakeRMInst(X86::CMP8rm , FrameIndex, MI);
314    case X86::CMP16rr:   return MakeRMInst(X86::CMP16rm, FrameIndex, MI);
315    case X86::CMP32rr:   return MakeRMInst(X86::CMP32rm, FrameIndex, MI);
316    case X86::MOVSX16rr8:return MakeRMInst(X86::MOVSX16rm8 , FrameIndex, MI);
317    case X86::MOVSX32rr8:return MakeRMInst(X86::MOVSX32rm8, FrameIndex, MI);
318    case X86::MOVSX32rr16:return MakeRMInst(X86::MOVSX32rm16, FrameIndex, MI);
319    case X86::MOVZX16rr8:return MakeRMInst(X86::MOVZX16rm8 , FrameIndex, MI);
320    case X86::MOVZX32rr8:  return MakeRMInst(X86::MOVZX32rm8, FrameIndex, MI);
321    case X86::MOVZX32rr16:return MakeRMInst(X86::MOVZX32rm16, FrameIndex, MI);
322    }
323  }
324  if (PrintFailedFusing)
325    std::cerr << "We failed to fuse: " << *MI;
326  return NULL;
327}
328
329//===----------------------------------------------------------------------===//
330// Stack Frame Processing methods
331//===----------------------------------------------------------------------===//
332
333// hasFP - Return true if the specified function should have a dedicated frame
334// pointer register.  This is true if the function has variable sized allocas or
335// if frame pointer elimination is disabled.
336//
337static bool hasFP(MachineFunction &MF) {
338  return NoFramePointerElim || MF.getFrameInfo()->hasVarSizedObjects();
339}
340
341void X86RegisterInfo::
342eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
343                              MachineBasicBlock::iterator I) const {
344  if (hasFP(MF)) {
345    // If we have a frame pointer, turn the adjcallstackup instruction into a
346    // 'sub ESP, <amt>' and the adjcallstackdown instruction into 'add ESP,
347    // <amt>'
348    MachineInstr *Old = I;
349    unsigned Amount = Old->getOperand(0).getImmedValue();
350    if (Amount != 0) {
351      // We need to keep the stack aligned properly.  To do this, we round the
352      // amount of space needed for the outgoing arguments up to the next
353      // alignment boundary.
354      unsigned Align = MF.getTarget().getFrameInfo()->getStackAlignment();
355      Amount = (Amount+Align-1)/Align*Align;
356
357      MachineInstr *New;
358      if (Old->getOpcode() == X86::ADJCALLSTACKDOWN) {
359	New=BuildMI(X86::SUB32ri, 1, X86::ESP, MachineOperand::UseAndDef)
360              .addZImm(Amount);
361      } else {
362	assert(Old->getOpcode() == X86::ADJCALLSTACKUP);
363	New=BuildMI(X86::ADD32ri, 1, X86::ESP, MachineOperand::UseAndDef)
364              .addZImm(Amount);
365      }
366
367      // Replace the pseudo instruction with a new instruction...
368      MBB.insert(I, New);
369    }
370  }
371
372  MBB.erase(I);
373}
374
375void X86RegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II) const{
376  unsigned i = 0;
377  MachineInstr &MI = *II;
378  MachineFunction &MF = *MI.getParent()->getParent();
379  while (!MI.getOperand(i).isFrameIndex()) {
380    ++i;
381    assert(i < MI.getNumOperands() && "Instr doesn't have FrameIndex operand!");
382  }
383
384  int FrameIndex = MI.getOperand(i).getFrameIndex();
385
386  // This must be part of a four operand memory reference.  Replace the
387  // FrameIndex with base register with EBP.  Add add an offset to the offset.
388  MI.SetMachineOperandReg(i, hasFP(MF) ? X86::EBP : X86::ESP);
389
390  // Now add the frame object offset to the offset from EBP.
391  int Offset = MF.getFrameInfo()->getObjectOffset(FrameIndex) +
392               MI.getOperand(i+3).getImmedValue()+4;
393
394  if (!hasFP(MF))
395    Offset += MF.getFrameInfo()->getStackSize();
396  else
397    Offset += 4;  // Skip the saved EBP
398
399  MI.SetMachineOperandConst(i+3, MachineOperand::MO_SignExtendedImmed, Offset);
400}
401
402void
403X86RegisterInfo::processFunctionBeforeFrameFinalized(MachineFunction &MF) const{
404  if (hasFP(MF)) {
405    // Create a frame entry for the EBP register that must be saved.
406    int FrameIdx = MF.getFrameInfo()->CreateFixedObject(4, -8);
407    assert(FrameIdx == MF.getFrameInfo()->getObjectIndexBegin() &&
408           "Slot for EBP register must be last in order to be found!");
409  }
410}
411
412void X86RegisterInfo::emitPrologue(MachineFunction &MF) const {
413  MachineBasicBlock &MBB = MF.front();   // Prolog goes in entry BB
414  MachineBasicBlock::iterator MBBI = MBB.begin();
415  MachineFrameInfo *MFI = MF.getFrameInfo();
416  MachineInstr *MI;
417
418  // Get the number of bytes to allocate from the FrameInfo
419  unsigned NumBytes = MFI->getStackSize();
420  if (hasFP(MF)) {
421    // Get the offset of the stack slot for the EBP register... which is
422    // guaranteed to be the last slot by processFunctionBeforeFrameFinalized.
423    int EBPOffset = MFI->getObjectOffset(MFI->getObjectIndexBegin())+4;
424
425    if (NumBytes) {   // adjust stack pointer: ESP -= numbytes
426      MI= BuildMI(X86::SUB32ri, 1, X86::ESP, MachineOperand::UseAndDef)
427            .addZImm(NumBytes);
428      MBB.insert(MBBI, MI);
429    }
430
431    // Save EBP into the appropriate stack slot...
432    MI = addRegOffset(BuildMI(X86::MOV32mr, 5),    // mov [ESP-<offset>], EBP
433		      X86::ESP, EBPOffset+NumBytes).addReg(X86::EBP);
434    MBB.insert(MBBI, MI);
435
436    // Update EBP with the new base value...
437    if (NumBytes == 4)    // mov EBP, ESP
438      MI = BuildMI(X86::MOV32rr, 2, X86::EBP).addReg(X86::ESP);
439    else                  // lea EBP, [ESP+StackSize]
440      MI = addRegOffset(BuildMI(X86::LEA32r, 5, X86::EBP), X86::ESP,NumBytes-4);
441
442    MBB.insert(MBBI, MI);
443
444  } else {
445    if (MFI->hasCalls()) {
446      // When we have no frame pointer, we reserve argument space for call sites
447      // in the function immediately on entry to the current function.  This
448      // eliminates the need for add/sub ESP brackets around call sites.
449      //
450      NumBytes += MFI->getMaxCallFrameSize();
451
452      // Round the size to a multiple of the alignment (don't forget the 4 byte
453      // offset though).
454      unsigned Align = MF.getTarget().getFrameInfo()->getStackAlignment();
455      NumBytes = ((NumBytes+4)+Align-1)/Align*Align - 4;
456    }
457
458    // Update frame info to pretend that this is part of the stack...
459    MFI->setStackSize(NumBytes);
460
461    if (NumBytes) {
462      // adjust stack pointer: ESP -= numbytes
463      MI= BuildMI(X86::SUB32ri, 1, X86::ESP, MachineOperand::UseAndDef)
464            .addZImm(NumBytes);
465      MBB.insert(MBBI, MI);
466    }
467  }
468}
469
470void X86RegisterInfo::emitEpilogue(MachineFunction &MF,
471                                   MachineBasicBlock &MBB) const {
472  const MachineFrameInfo *MFI = MF.getFrameInfo();
473  MachineBasicBlock::iterator MBBI = prior(MBB.end());
474  MachineInstr *MI;
475  assert(MBBI->getOpcode() == X86::RET &&
476         "Can only insert epilog into returning blocks");
477
478  if (hasFP(MF)) {
479    // Get the offset of the stack slot for the EBP register... which is
480    // guaranteed to be the last slot by processFunctionBeforeFrameFinalized.
481    int EBPOffset = MFI->getObjectOffset(MFI->getObjectIndexEnd()-1)+4;
482
483    // mov ESP, EBP
484    MI = BuildMI(X86::MOV32rr, 1,X86::ESP).addReg(X86::EBP);
485    MBB.insert(MBBI, MI);
486
487    // pop EBP
488    MI = BuildMI(X86::POP32r, 0, X86::EBP);
489    MBB.insert(MBBI, MI);
490  } else {
491    // Get the number of bytes allocated from the FrameInfo...
492    unsigned NumBytes = MFI->getStackSize();
493
494    if (NumBytes) {    // adjust stack pointer back: ESP += numbytes
495      MI =BuildMI(X86::ADD32ri, 1, X86::ESP, MachineOperand::UseAndDef)
496            .addZImm(NumBytes);
497      MBB.insert(MBBI, MI);
498    }
499  }
500}
501
502#include "X86GenRegisterInfo.inc"
503
504const TargetRegisterClass*
505X86RegisterInfo::getRegClassForType(const Type* Ty) const {
506  switch (Ty->getTypeID()) {
507  case Type::LongTyID:
508  case Type::ULongTyID: assert(0 && "Long values can't fit in registers!");
509  default:              assert(0 && "Invalid type to getClass!");
510  case Type::BoolTyID:
511  case Type::SByteTyID:
512  case Type::UByteTyID:   return &R8Instance;
513  case Type::ShortTyID:
514  case Type::UShortTyID:  return &R16Instance;
515  case Type::IntTyID:
516  case Type::UIntTyID:
517  case Type::PointerTyID: return &R32Instance;
518
519  case Type::FloatTyID:
520  case Type::DoubleTyID: return &RFPInstance;
521  }
522}
523