1 //===- X86RegisterInfo.cpp - X86 Register Information -----------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
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.
8 //===----------------------------------------------------------------------===//
10 // This file contains the X86 implementation of the MRegisterInfo class. This
11 // file is responsible for the frame pointer elimination optimization on X86.
13 //===----------------------------------------------------------------------===//
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"
32 NoFPElim("disable-fp-elim",
33 cl::desc("Disable frame pointer elimination optimization"));
35 NoFusing("disable-spill-fusing",
36 cl::desc("Disable fusing of spill code into instructions"));
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"),
44 X86RegisterInfo::X86RegisterInfo()
45 : X86GenRegisterInfo(X86::ADJCALLSTACKDOWN, X86::ADJCALLSTACKUP) {}
47 static unsigned getIdx(const TargetRegisterClass *RC) {
48 switch (RC->getSize()) {
49 default: assert(0 && "Invalid data size!");
57 int 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);
69 int 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));
80 int 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));
90 static MachineInstr *MakeMInst(unsigned Opcode, unsigned FrameIndex,
92 return addFrameReference(BuildMI(Opcode, 4), FrameIndex);
95 static MachineInstr *MakeMRInst(unsigned Opcode, unsigned FrameIndex,
97 return addFrameReference(BuildMI(Opcode, 5), FrameIndex)
98 .addReg(MI->getOperand(1).getReg());
101 static MachineInstr *MakeMRIInst(unsigned Opcode, unsigned FrameIndex,
103 return addFrameReference(BuildMI(Opcode, 5), FrameIndex)
104 .addReg(MI->getOperand(1).getReg())
105 .addZImm(MI->getOperand(2).getImmedValue());
108 static MachineInstr *MakeMIInst(unsigned Opcode, unsigned FrameIndex,
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!");
120 static MachineInstr *MakeRMInst(unsigned Opcode, unsigned FrameIndex,
122 const MachineOperand& op = MI->getOperand(0);
123 return addFrameReference(BuildMI(Opcode, 5, op.getReg(), op.getUseType()),
127 static MachineInstr *MakeRMIInst(unsigned Opcode, unsigned FrameIndex,
129 const MachineOperand& op = MI->getOperand(0);
130 return addFrameReference(BuildMI(Opcode, 5, op.getReg(), op.getUseType()),
131 FrameIndex).addZImm(MI->getOperand(2).getImmedValue());
135 bool X86RegisterInfo::foldMemoryOperand(MachineBasicBlock::iterator &MI,
136 unsigned i, int FrameIndex) const {
137 if (NoFusing) return false;
139 /// FIXME: This should obviously be autogenerated by tablegen when patterns
141 MachineBasicBlock& MBB = *MI->getParent();
142 MachineInstr* NI = 0;
144 switch(MI->getOpcode()) {
145 case X86::XCHGrr8: NI = MakeMRInst(X86::XCHGmr8 ,FrameIndex, MI); break;
146 case X86::XCHGrr16:NI = MakeMRInst(X86::XCHGmr16,FrameIndex, MI); break;
147 case X86::XCHGrr32:NI = MakeMRInst(X86::XCHGmr32,FrameIndex, MI); break;
148 case X86::MOVrr8: NI = MakeMRInst(X86::MOVmr8 , FrameIndex, MI); break;
149 case X86::MOVrr16: NI = MakeMRInst(X86::MOVmr16, FrameIndex, MI); break;
150 case X86::MOVrr32: NI = MakeMRInst(X86::MOVmr32, FrameIndex, MI); break;
151 case X86::MOVri8: NI = MakeMIInst(X86::MOVmi8 , FrameIndex, MI); break;
152 case X86::MOVri16: NI = MakeMIInst(X86::MOVmi16, FrameIndex, MI); break;
153 case X86::MOVri32: NI = MakeMIInst(X86::MOVmi32, FrameIndex, MI); break;
154 case X86::MULr8: NI = MakeMInst( X86::MULm8 , FrameIndex, MI); break;
155 case X86::MULr16: NI = MakeMInst( X86::MULm16, FrameIndex, MI); break;
156 case X86::MULr32: NI = MakeMInst( X86::MULm32, FrameIndex, MI); break;
157 case X86::DIVr8: NI = MakeMInst( X86::DIVm8 , FrameIndex, MI); break;
158 case X86::DIVr16: NI = MakeMInst( X86::DIVm16, FrameIndex, MI); break;
159 case X86::DIVr32: NI = MakeMInst( X86::DIVm32, FrameIndex, MI); break;
160 case X86::IDIVr8: NI = MakeMInst( X86::IDIVm8 , FrameIndex, MI); break;
161 case X86::IDIVr16: NI = MakeMInst( X86::IDIVm16, FrameIndex, MI); break;
162 case X86::IDIVr32: NI = MakeMInst( X86::IDIVm32, FrameIndex, MI); break;
163 case X86::NEGr8: NI = MakeMInst( X86::NEGm8 , FrameIndex, MI); break;
164 case X86::NEGr16: NI = MakeMInst( X86::NEGm16, FrameIndex, MI); break;
165 case X86::NEGr32: NI = MakeMInst( X86::NEGm32, FrameIndex, MI); break;
166 case X86::NOTr8: NI = MakeMInst( X86::NOTm8 , FrameIndex, MI); break;
167 case X86::NOTr16: NI = MakeMInst( X86::NOTm16, FrameIndex, MI); break;
168 case X86::NOTr32: NI = MakeMInst( X86::NOTm32, FrameIndex, MI); break;
169 case X86::INCr8: NI = MakeMInst( X86::INCm8 , FrameIndex, MI); break;
170 case X86::INCr16: NI = MakeMInst( X86::INCm16, FrameIndex, MI); break;
171 case X86::INCr32: NI = MakeMInst( X86::INCm32, FrameIndex, MI); break;
172 case X86::DECr8: NI = MakeMInst( X86::DECm8 , FrameIndex, MI); break;
173 case X86::DECr16: NI = MakeMInst( X86::DECm16, FrameIndex, MI); break;
174 case X86::DECr32: NI = MakeMInst( X86::DECm32, FrameIndex, MI); break;
175 case X86::ADDrr8: NI = MakeMRInst(X86::ADDmr8 , FrameIndex, MI); break;
176 case X86::ADDrr16: NI = MakeMRInst(X86::ADDmr16, FrameIndex, MI); break;
177 case X86::ADDrr32: NI = MakeMRInst(X86::ADDmr32, FrameIndex, MI); break;
178 case X86::ADCrr32: NI = MakeMRInst(X86::ADCmr32, FrameIndex, MI); break;
179 case X86::ADDri8: NI = MakeMIInst(X86::ADDmi8 , FrameIndex, MI); break;
180 case X86::ADDri16: NI = MakeMIInst(X86::ADDmi16, FrameIndex, MI); break;
181 case X86::ADDri32: NI = MakeMIInst(X86::ADDmi32, FrameIndex, MI); break;
182 case X86::SUBrr8: NI = MakeMRInst(X86::SUBmr8 , FrameIndex, MI); break;
183 case X86::SUBrr16: NI = MakeMRInst(X86::SUBmr16, FrameIndex, MI); break;
184 case X86::SUBrr32: NI = MakeMRInst(X86::SUBmr32, FrameIndex, MI); break;
185 case X86::SBBrr32: NI = MakeMRInst(X86::SBBmr32, FrameIndex, MI); break;
186 case X86::SUBri8: NI = MakeMIInst(X86::SUBmi8 , FrameIndex, MI); break;
187 case X86::SUBri16: NI = MakeMIInst(X86::SUBmi16, FrameIndex, MI); break;
188 case X86::SUBri32: NI = MakeMIInst(X86::SUBmi32, FrameIndex, MI); break;
189 case X86::ANDrr8: NI = MakeMRInst(X86::ANDmr8 , FrameIndex, MI); break;
190 case X86::ANDrr16: NI = MakeMRInst(X86::ANDmr16, FrameIndex, MI); break;
191 case X86::ANDrr32: NI = MakeMRInst(X86::ANDmr32, FrameIndex, MI); break;
192 case X86::ANDri8: NI = MakeMIInst(X86::ANDmi8 , FrameIndex, MI); break;
193 case X86::ANDri16: NI = MakeMIInst(X86::ANDmi16, FrameIndex, MI); break;
194 case X86::ANDri32: NI = MakeMIInst(X86::ANDmi32, FrameIndex, MI); break;
195 case X86::ORrr8: NI = MakeMRInst(X86::ORmr8 , FrameIndex, MI); break;
196 case X86::ORrr16: NI = MakeMRInst(X86::ORmr16, FrameIndex, MI); break;
197 case X86::ORrr32: NI = MakeMRInst(X86::ORmr32, FrameIndex, MI); break;
198 case X86::ORri8: NI = MakeMIInst(X86::ORmi8 , FrameIndex, MI); break;
199 case X86::ORri16: NI = MakeMIInst(X86::ORmi16, FrameIndex, MI); break;
200 case X86::ORri32: NI = MakeMIInst(X86::ORmi32, FrameIndex, MI); break;
201 case X86::XORrr8: NI = MakeMRInst(X86::XORmr8 , FrameIndex, MI); break;
202 case X86::XORrr16: NI = MakeMRInst(X86::XORmr16, FrameIndex, MI); break;
203 case X86::XORrr32: NI = MakeMRInst(X86::XORmr32, FrameIndex, MI); break;
204 case X86::XORri8: NI = MakeMIInst(X86::XORmi8 , FrameIndex, MI); break;
205 case X86::XORri16: NI = MakeMIInst(X86::XORmi16, FrameIndex, MI); break;
206 case X86::XORri32: NI = MakeMIInst(X86::XORmi32, FrameIndex, MI); break;
207 case X86::SHLrCL8: NI = MakeMInst( X86::SHLmCL8 ,FrameIndex, MI); break;
208 case X86::SHLrCL16:NI = MakeMInst( X86::SHLmCL16,FrameIndex, MI); break;
209 case X86::SHLrCL32:NI = MakeMInst( X86::SHLmCL32,FrameIndex, MI); break;
210 case X86::SHLri8: NI = MakeMIInst(X86::SHLmi8 , FrameIndex, MI); break;
211 case X86::SHLri16: NI = MakeMIInst(X86::SHLmi16, FrameIndex, MI); break;
212 case X86::SHLri32: NI = MakeMIInst(X86::SHLmi32, FrameIndex, MI); break;
213 case X86::SHRrCL8: NI = MakeMInst( X86::SHRmCL8 ,FrameIndex, MI); break;
214 case X86::SHRrCL16:NI = MakeMInst( X86::SHRmCL16,FrameIndex, MI); break;
215 case X86::SHRrCL32:NI = MakeMInst( X86::SHRmCL32,FrameIndex, MI); break;
216 case X86::SHRri8: NI = MakeMIInst(X86::SHRmi8 , FrameIndex, MI); break;
217 case X86::SHRri16: NI = MakeMIInst(X86::SHRmi16, FrameIndex, MI); break;
218 case X86::SHRri32: NI = MakeMIInst(X86::SHRmi32, FrameIndex, MI); break;
219 case X86::SARrCL8: NI = MakeMInst( X86::SARmCL8 ,FrameIndex, MI); break;
220 case X86::SARrCL16:NI = MakeMInst( X86::SARmCL16,FrameIndex, MI); break;
221 case X86::SARrCL32:NI = MakeMInst( X86::SARmCL32,FrameIndex, MI); break;
222 case X86::SARri8: NI = MakeMIInst(X86::SARmi8 , FrameIndex, MI); break;
223 case X86::SARri16: NI = MakeMIInst(X86::SARmi16, FrameIndex, MI); break;
224 case X86::SARri32: NI = MakeMIInst(X86::SARmi32, FrameIndex, MI); break;
225 case X86::SHLDrrCL32:NI = MakeMRInst( X86::SHLDmrCL32,FrameIndex, MI);break;
226 case X86::SHLDrri32: NI = MakeMRIInst(X86::SHLDmri32, FrameIndex, MI);break;
227 case X86::SHRDrrCL32:NI = MakeMRInst( X86::SHRDmrCL32,FrameIndex, MI);break;
228 case X86::SHRDrri32: NI = MakeMRIInst(X86::SHRDmri32, FrameIndex, MI);break;
229 case X86::TESTrr8: NI = MakeMRInst(X86::TESTmr8 ,FrameIndex, MI); break;
230 case X86::TESTrr16:NI = MakeMRInst(X86::TESTmr16,FrameIndex, MI); break;
231 case X86::TESTrr32:NI = MakeMRInst(X86::TESTmr32,FrameIndex, MI); break;
232 case X86::TESTri8: NI = MakeMIInst(X86::TESTmi8 ,FrameIndex, MI); break;
233 case X86::TESTri16:NI = MakeMIInst(X86::TESTmi16,FrameIndex, MI); break;
234 case X86::TESTri32:NI = MakeMIInst(X86::TESTmi32,FrameIndex, MI); break;
235 case X86::CMPrr8: NI = MakeMRInst(X86::CMPmr8 , FrameIndex, MI); break;
236 case X86::CMPrr16: NI = MakeMRInst(X86::CMPmr16, FrameIndex, MI); break;
237 case X86::CMPrr32: NI = MakeMRInst(X86::CMPmr32, FrameIndex, MI); break;
238 case X86::CMPri8: NI = MakeMIInst(X86::CMPmi8 , FrameIndex, MI); break;
239 case X86::CMPri16: NI = MakeMIInst(X86::CMPmi16, FrameIndex, MI); break;
240 case X86::CMPri32: NI = MakeMIInst(X86::CMPmi32, FrameIndex, MI); break;
241 default: break; // Cannot fold
244 switch(MI->getOpcode()) {
245 case X86::XCHGrr8: NI = MakeRMInst(X86::XCHGrm8 ,FrameIndex, MI); break;
246 case X86::XCHGrr16:NI = MakeRMInst(X86::XCHGrm16,FrameIndex, MI); break;
247 case X86::XCHGrr32:NI = MakeRMInst(X86::XCHGrm32,FrameIndex, MI); break;
248 case X86::MOVrr8: NI = MakeRMInst(X86::MOVrm8 , FrameIndex, MI); break;
249 case X86::MOVrr16: NI = MakeRMInst(X86::MOVrm16, FrameIndex, MI); break;
250 case X86::MOVrr32: NI = MakeRMInst(X86::MOVrm32, FrameIndex, MI); break;
251 case X86::ADDrr8: NI = MakeRMInst(X86::ADDrm8 , FrameIndex, MI); break;
252 case X86::ADDrr16: NI = MakeRMInst(X86::ADDrm16, FrameIndex, MI); break;
253 case X86::ADDrr32: NI = MakeRMInst(X86::ADDrm32, FrameIndex, MI); break;
254 case X86::ADCrr32: NI = MakeRMInst(X86::ADCrm32, FrameIndex, MI); break;
255 case X86::SUBrr8: NI = MakeRMInst(X86::SUBrm8 , FrameIndex, MI); break;
256 case X86::SUBrr16: NI = MakeRMInst(X86::SUBrm16, FrameIndex, MI); break;
257 case X86::SUBrr32: NI = MakeRMInst(X86::SUBrm32, FrameIndex, MI); break;
258 case X86::SBBrr32: NI = MakeRMInst(X86::SBBrm32, FrameIndex, MI); break;
259 case X86::ANDrr8: NI = MakeRMInst(X86::ANDrm8 , FrameIndex, MI); break;
260 case X86::ANDrr16: NI = MakeRMInst(X86::ANDrm16, FrameIndex, MI); break;
261 case X86::ANDrr32: NI = MakeRMInst(X86::ANDrm32, FrameIndex, MI); break;
262 case X86::ORrr8: NI = MakeRMInst(X86::ORrm8 , FrameIndex, MI); break;
263 case X86::ORrr16: NI = MakeRMInst(X86::ORrm16, FrameIndex, MI); break;
264 case X86::ORrr32: NI = MakeRMInst(X86::ORrm32, FrameIndex, MI); break;
265 case X86::XORrr8: NI = MakeRMInst(X86::XORrm8 , FrameIndex, MI); break;
266 case X86::XORrr16: NI = MakeRMInst(X86::XORrm16, FrameIndex, MI); break;
267 case X86::XORrr32: NI = MakeRMInst(X86::XORrm32, FrameIndex, MI); break;
268 case X86::TESTrr8: NI = MakeRMInst(X86::TESTrm8 ,FrameIndex, MI); break;
269 case X86::TESTrr16:NI = MakeRMInst(X86::TESTrm16,FrameIndex, MI); break;
270 case X86::TESTrr32:NI = MakeRMInst(X86::TESTrm32,FrameIndex, MI); break;
271 case X86::IMULrr16:NI = MakeRMInst(X86::IMULrm16,FrameIndex, MI); break;
272 case X86::IMULrr32:NI = MakeRMInst(X86::IMULrm32,FrameIndex, MI); break;
273 case X86::IMULrri16: NI = MakeRMIInst(X86::IMULrmi16, FrameIndex, MI);break;
274 case X86::IMULrri32: NI = MakeRMIInst(X86::IMULrmi32, FrameIndex, MI);break;
275 case X86::CMPrr8: NI = MakeRMInst(X86::CMPrm8 , FrameIndex, MI); break;
276 case X86::CMPrr16: NI = MakeRMInst(X86::CMPrm16, FrameIndex, MI); break;
277 case X86::CMPrr32: NI = MakeRMInst(X86::CMPrm32, FrameIndex, MI); break;
278 case X86::MOVSXr16r8: NI = MakeRMInst(X86::MOVSXr16m8 , FrameIndex, MI); break;
279 case X86::MOVSXr32r8: NI = MakeRMInst(X86::MOVSXr32m8, FrameIndex, MI); break;
280 case X86::MOVSXr32r16:NI = MakeRMInst(X86::MOVSXr32m16, FrameIndex, MI); break;
281 case X86::MOVZXr16r8: NI = MakeRMInst(X86::MOVZXr16m8 , FrameIndex, MI); break;
282 case X86::MOVZXr32r8: NI = MakeRMInst(X86::MOVZXr32m8, FrameIndex, MI); break;
283 case X86::MOVZXr32r16:NI = MakeRMInst(X86::MOVZXr32m16, FrameIndex, MI); break;
288 MI = MBB.insert(MBB.erase(MI), NI);
291 if (PrintFailedFusing)
292 std::cerr << "We failed to fuse: " << *MI;
297 //===----------------------------------------------------------------------===//
298 // Stack Frame Processing methods
299 //===----------------------------------------------------------------------===//
301 // hasFP - Return true if the specified function should have a dedicated frame
302 // pointer register. This is true if the function has variable sized allocas or
303 // if frame pointer elimination is disabled.
305 static bool hasFP(MachineFunction &MF) {
306 return NoFPElim || MF.getFrameInfo()->hasVarSizedObjects();
309 void X86RegisterInfo::
310 eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
311 MachineBasicBlock::iterator I) const {
313 // If we have a frame pointer, turn the adjcallstackup instruction into a
314 // 'sub ESP, <amt>' and the adjcallstackdown instruction into 'add ESP,
316 MachineInstr *Old = I;
317 unsigned Amount = Old->getOperand(0).getImmedValue();
319 // We need to keep the stack aligned properly. To do this, we round the
320 // amount of space needed for the outgoing arguments up to the next
321 // alignment boundary.
322 unsigned Align = MF.getTarget().getFrameInfo().getStackAlignment();
323 Amount = (Amount+Align-1)/Align*Align;
326 if (Old->getOpcode() == X86::ADJCALLSTACKDOWN) {
327 New=BuildMI(X86::SUBri32, 1, X86::ESP, MachineOperand::UseAndDef)
330 assert(Old->getOpcode() == X86::ADJCALLSTACKUP);
331 New=BuildMI(X86::ADDri32, 1, X86::ESP, MachineOperand::UseAndDef)
335 // Replace the pseudo instruction with a new instruction...
343 void X86RegisterInfo::eliminateFrameIndex(MachineFunction &MF,
344 MachineBasicBlock::iterator II) const {
346 MachineInstr &MI = *II;
347 while (!MI.getOperand(i).isFrameIndex()) {
349 assert(i < MI.getNumOperands() && "Instr doesn't have FrameIndex operand!");
352 int FrameIndex = MI.getOperand(i).getFrameIndex();
354 // This must be part of a four operand memory reference. Replace the
355 // FrameIndex with base register with EBP. Add add an offset to the offset.
356 MI.SetMachineOperandReg(i, hasFP(MF) ? X86::EBP : X86::ESP);
358 // Now add the frame object offset to the offset from EBP.
359 int Offset = MF.getFrameInfo()->getObjectOffset(FrameIndex) +
360 MI.getOperand(i+3).getImmedValue()+4;
363 Offset += MF.getFrameInfo()->getStackSize();
365 Offset += 4; // Skip the saved EBP
367 MI.SetMachineOperandConst(i+3, MachineOperand::MO_SignExtendedImmed, Offset);
371 X86RegisterInfo::processFunctionBeforeFrameFinalized(MachineFunction &MF) const{
373 // Create a frame entry for the EBP register that must be saved.
374 int FrameIdx = MF.getFrameInfo()->CreateFixedObject(4, -8);
375 assert(FrameIdx == MF.getFrameInfo()->getObjectIndexBegin() &&
376 "Slot for EBP register must be last in order to be found!");
380 void X86RegisterInfo::emitPrologue(MachineFunction &MF) const {
381 MachineBasicBlock &MBB = MF.front(); // Prolog goes in entry BB
382 MachineBasicBlock::iterator MBBI = MBB.begin();
383 MachineFrameInfo *MFI = MF.getFrameInfo();
386 // Get the number of bytes to allocate from the FrameInfo
387 unsigned NumBytes = MFI->getStackSize();
389 // Get the offset of the stack slot for the EBP register... which is
390 // guaranteed to be the last slot by processFunctionBeforeFrameFinalized.
391 int EBPOffset = MFI->getObjectOffset(MFI->getObjectIndexBegin())+4;
393 if (NumBytes) { // adjust stack pointer: ESP -= numbytes
394 MI= BuildMI(X86::SUBri32, 1, X86::ESP, MachineOperand::UseAndDef)
396 MBB.insert(MBBI, MI);
399 // Save EBP into the appropriate stack slot...
400 MI = addRegOffset(BuildMI(X86::MOVmr32, 5), // mov [ESP-<offset>], EBP
401 X86::ESP, EBPOffset+NumBytes).addReg(X86::EBP);
402 MBB.insert(MBBI, MI);
404 // Update EBP with the new base value...
405 if (NumBytes == 4) // mov EBP, ESP
406 MI = BuildMI(X86::MOVrr32, 2, X86::EBP).addReg(X86::ESP);
407 else // lea EBP, [ESP+StackSize]
408 MI = addRegOffset(BuildMI(X86::LEAr32, 5, X86::EBP), X86::ESP,NumBytes-4);
410 MBB.insert(MBBI, MI);
413 if (MFI->hasCalls()) {
414 // When we have no frame pointer, we reserve argument space for call sites
415 // in the function immediately on entry to the current function. This
416 // eliminates the need for add/sub ESP brackets around call sites.
418 NumBytes += MFI->getMaxCallFrameSize();
420 // Round the size to a multiple of the alignment (don't forget the 4 byte
422 unsigned Align = MF.getTarget().getFrameInfo().getStackAlignment();
423 NumBytes = ((NumBytes+4)+Align-1)/Align*Align - 4;
426 // Update frame info to pretend that this is part of the stack...
427 MFI->setStackSize(NumBytes);
430 // adjust stack pointer: ESP -= numbytes
431 MI= BuildMI(X86::SUBri32, 1, X86::ESP, MachineOperand::UseAndDef)
433 MBB.insert(MBBI, MI);
438 void X86RegisterInfo::emitEpilogue(MachineFunction &MF,
439 MachineBasicBlock &MBB) const {
440 const MachineFrameInfo *MFI = MF.getFrameInfo();
441 MachineBasicBlock::iterator MBBI = prior(MBB.end());
443 assert(MBBI->getOpcode() == X86::RET &&
444 "Can only insert epilog into returning blocks");
447 // Get the offset of the stack slot for the EBP register... which is
448 // guaranteed to be the last slot by processFunctionBeforeFrameFinalized.
449 int EBPOffset = MFI->getObjectOffset(MFI->getObjectIndexEnd()-1)+4;
452 MI = BuildMI(X86::MOVrr32, 1,X86::ESP).addReg(X86::EBP);
453 MBB.insert(MBBI, MI);
456 MI = BuildMI(X86::POPr32, 0, X86::EBP);
457 MBB.insert(MBBI, MI);
459 // Get the number of bytes allocated from the FrameInfo...
460 unsigned NumBytes = MFI->getStackSize();
462 if (NumBytes) { // adjust stack pointer back: ESP += numbytes
463 MI =BuildMI(X86::ADDri32, 1, X86::ESP, MachineOperand::UseAndDef)
465 MBB.insert(MBBI, MI);
470 #include "X86GenRegisterInfo.inc"
472 const TargetRegisterClass*
473 X86RegisterInfo::getRegClassForType(const Type* Ty) const {
474 switch (Ty->getPrimitiveID()) {
476 case Type::ULongTyID: assert(0 && "Long values can't fit in registers!");
477 default: assert(0 && "Invalid type to getClass!");
479 case Type::SByteTyID:
480 case Type::UByteTyID: return &R8Instance;
481 case Type::ShortTyID:
482 case Type::UShortTyID: return &R16Instance;
485 case Type::PointerTyID: return &R32Instance;
487 case Type::FloatTyID:
488 case Type::DoubleTyID: return &RFPInstance;