X86RegisterInfo.cpp revision e56508eb7e21f6e0bfd3948379791e412f82ce58
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, 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, 5), 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, 5, op.getReg(), op.getUseType()), 131 FrameIndex).addZImm(MI->getOperand(2).getImmedValue()); 132} 133 134 135bool X86RegisterInfo::foldMemoryOperand(MachineBasicBlock::iterator &MI, 136 unsigned i, int FrameIndex) const { 137 if (NoFusing) return false; 138 139 /// FIXME: This should obviously be autogenerated by tablegen when patterns 140 /// are available! 141 MachineBasicBlock& MBB = *MI->getParent(); 142 MachineInstr* NI = 0; 143 if (i == 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 242 } 243 } else if (i == 1) { 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; 284 default: break; 285 } 286 } 287 if (NI) { 288 MI = MBB.insert(MBB.erase(MI), NI); 289 return true; 290 } else { 291 if (PrintFailedFusing) 292 std::cerr << "We failed to fuse: " << *MI; 293 return false; 294 } 295} 296 297//===----------------------------------------------------------------------===// 298// Stack Frame Processing methods 299//===----------------------------------------------------------------------===// 300 301// 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. 304// 305static bool hasFP(MachineFunction &MF) { 306 return NoFPElim || MF.getFrameInfo()->hasVarSizedObjects(); 307} 308 309void X86RegisterInfo:: 310eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB, 311 MachineBasicBlock::iterator I) const { 312 if (hasFP(MF)) { 313 // If we have a frame pointer, turn the adjcallstackup instruction into a 314 // 'sub ESP, <amt>' and the adjcallstackdown instruction into 'add ESP, 315 // <amt>' 316 MachineInstr *Old = I; 317 unsigned Amount = Old->getOperand(0).getImmedValue(); 318 if (Amount != 0) { 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; 324 325 MachineInstr *New; 326 if (Old->getOpcode() == X86::ADJCALLSTACKDOWN) { 327 New=BuildMI(X86::SUBri32, 1, X86::ESP, MachineOperand::UseAndDef) 328 .addZImm(Amount); 329 } else { 330 assert(Old->getOpcode() == X86::ADJCALLSTACKUP); 331 New=BuildMI(X86::ADDri32, 1, X86::ESP, MachineOperand::UseAndDef) 332 .addZImm(Amount); 333 } 334 335 // Replace the pseudo instruction with a new instruction... 336 MBB.insert(I, New); 337 } 338 } 339 340 MBB.erase(I); 341} 342 343void X86RegisterInfo::eliminateFrameIndex(MachineFunction &MF, 344 MachineBasicBlock::iterator II) const { 345 unsigned i = 0; 346 MachineInstr &MI = *II; 347 while (!MI.getOperand(i).isFrameIndex()) { 348 ++i; 349 assert(i < MI.getNumOperands() && "Instr doesn't have FrameIndex operand!"); 350 } 351 352 int FrameIndex = MI.getOperand(i).getFrameIndex(); 353 354 // 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); 357 358 // 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; 361 362 if (!hasFP(MF)) 363 Offset += MF.getFrameInfo()->getStackSize(); 364 else 365 Offset += 4; // Skip the saved EBP 366 367 MI.SetMachineOperandConst(i+3, MachineOperand::MO_SignExtendedImmed, Offset); 368} 369 370void 371X86RegisterInfo::processFunctionBeforeFrameFinalized(MachineFunction &MF) const{ 372 if (hasFP(MF)) { 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!"); 377 } 378} 379 380void 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(); 384 MachineInstr *MI; 385 386 // Get the number of bytes to allocate from the FrameInfo 387 unsigned NumBytes = MFI->getStackSize(); 388 if (hasFP(MF)) { 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; 392 393 if (NumBytes) { // adjust stack pointer: ESP -= numbytes 394 MI= BuildMI(X86::SUBri32, 1, X86::ESP, MachineOperand::UseAndDef) 395 .addZImm(NumBytes); 396 MBB.insert(MBBI, MI); 397 } 398 399 // 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); 403 404 // 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); 409 410 MBB.insert(MBBI, MI); 411 412 } else { 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. 417 // 418 NumBytes += MFI->getMaxCallFrameSize(); 419 420 // Round the size to a multiple of the alignment (don't forget the 4 byte 421 // offset though). 422 unsigned Align = MF.getTarget().getFrameInfo().getStackAlignment(); 423 NumBytes = ((NumBytes+4)+Align-1)/Align*Align - 4; 424 } 425 426 // Update frame info to pretend that this is part of the stack... 427 MFI->setStackSize(NumBytes); 428 429 if (NumBytes) { 430 // adjust stack pointer: ESP -= numbytes 431 MI= BuildMI(X86::SUBri32, 1, X86::ESP, MachineOperand::UseAndDef) 432 .addZImm(NumBytes); 433 MBB.insert(MBBI, MI); 434 } 435 } 436} 437 438void X86RegisterInfo::emitEpilogue(MachineFunction &MF, 439 MachineBasicBlock &MBB) const { 440 const MachineFrameInfo *MFI = MF.getFrameInfo(); 441 MachineBasicBlock::iterator MBBI = prior(MBB.end()); 442 MachineInstr *MI; 443 assert(MBBI->getOpcode() == X86::RET && 444 "Can only insert epilog into returning blocks"); 445 446 if (hasFP(MF)) { 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; 450 451 // mov ESP, EBP 452 MI = BuildMI(X86::MOVrr32, 1,X86::ESP).addReg(X86::EBP); 453 MBB.insert(MBBI, MI); 454 455 // pop EBP 456 MI = BuildMI(X86::POPr32, 0, X86::EBP); 457 MBB.insert(MBBI, MI); 458 } else { 459 // Get the number of bytes allocated from the FrameInfo... 460 unsigned NumBytes = MFI->getStackSize(); 461 462 if (NumBytes) { // adjust stack pointer back: ESP += numbytes 463 MI =BuildMI(X86::ADDri32, 1, X86::ESP, MachineOperand::UseAndDef) 464 .addZImm(NumBytes); 465 MBB.insert(MBBI, MI); 466 } 467 } 468} 469 470#include "X86GenRegisterInfo.inc" 471 472const TargetRegisterClass* 473X86RegisterInfo::getRegClassForType(const Type* Ty) const { 474 switch (Ty->getPrimitiveID()) { 475 case Type::LongTyID: 476 case Type::ULongTyID: assert(0 && "Long values can't fit in registers!"); 477 default: assert(0 && "Invalid type to getClass!"); 478 case Type::BoolTyID: 479 case Type::SByteTyID: 480 case Type::UByteTyID: return &R8Instance; 481 case Type::ShortTyID: 482 case Type::UShortTyID: return &R16Instance; 483 case Type::IntTyID: 484 case Type::UIntTyID: 485 case Type::PointerTyID: return &R32Instance; 486 487 case Type::FloatTyID: 488 case Type::DoubleTyID: return &RFPInstance; 489 } 490} 491