ARMBaseRegisterInfo.cpp revision e922c0201916e0b980ab3cfe91e1413e68d55647
1//===- ARMBaseRegisterInfo.cpp - ARM Register Information -----------*- C++ -*-===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file contains the base ARM implementation of TargetRegisterInfo class. 11// 12//===----------------------------------------------------------------------===// 13 14#include "ARM.h" 15#include "ARMAddressingModes.h" 16#include "ARMBaseInstrInfo.h" 17#include "ARMBaseRegisterInfo.h" 18#include "ARMInstrInfo.h" 19#include "ARMMachineFunctionInfo.h" 20#include "ARMSubtarget.h" 21#include "llvm/Constants.h" 22#include "llvm/DerivedTypes.h" 23#include "llvm/Function.h" 24#include "llvm/LLVMContext.h" 25#include "llvm/CodeGen/MachineConstantPool.h" 26#include "llvm/CodeGen/MachineFrameInfo.h" 27#include "llvm/CodeGen/MachineFunction.h" 28#include "llvm/CodeGen/MachineInstrBuilder.h" 29#include "llvm/CodeGen/MachineLocation.h" 30#include "llvm/CodeGen/MachineRegisterInfo.h" 31#include "llvm/CodeGen/RegisterScavenging.h" 32#include "llvm/Support/ErrorHandling.h" 33#include "llvm/Support/raw_ostream.h" 34#include "llvm/Target/TargetFrameInfo.h" 35#include "llvm/Target/TargetMachine.h" 36#include "llvm/Target/TargetOptions.h" 37#include "llvm/ADT/BitVector.h" 38#include "llvm/ADT/SmallVector.h" 39using namespace llvm; 40 41unsigned ARMBaseRegisterInfo::getRegisterNumbering(unsigned RegEnum) { 42 using namespace ARM; 43 switch (RegEnum) { 44 case R0: case S0: case D0: return 0; 45 case R1: case S1: case D1: return 1; 46 case R2: case S2: case D2: return 2; 47 case R3: case S3: case D3: return 3; 48 case R4: case S4: case D4: return 4; 49 case R5: case S5: case D5: return 5; 50 case R6: case S6: case D6: return 6; 51 case R7: case S7: case D7: return 7; 52 case R8: case S8: case D8: return 8; 53 case R9: case S9: case D9: return 9; 54 case R10: case S10: case D10: return 10; 55 case R11: case S11: case D11: return 11; 56 case R12: case S12: case D12: return 12; 57 case SP: case S13: case D13: return 13; 58 case LR: case S14: case D14: return 14; 59 case PC: case S15: case D15: return 15; 60 case S16: return 16; 61 case S17: return 17; 62 case S18: return 18; 63 case S19: return 19; 64 case S20: return 20; 65 case S21: return 21; 66 case S22: return 22; 67 case S23: return 23; 68 case S24: return 24; 69 case S25: return 25; 70 case S26: return 26; 71 case S27: return 27; 72 case S28: return 28; 73 case S29: return 29; 74 case S30: return 30; 75 case S31: return 31; 76 default: 77 llvm_unreachable("Unknown ARM register!"); 78 } 79} 80 81unsigned ARMBaseRegisterInfo::getRegisterNumbering(unsigned RegEnum, 82 bool &isSPVFP) { 83 isSPVFP = false; 84 85 using namespace ARM; 86 switch (RegEnum) { 87 default: 88 llvm_unreachable("Unknown ARM register!"); 89 case R0: case D0: return 0; 90 case R1: case D1: return 1; 91 case R2: case D2: return 2; 92 case R3: case D3: return 3; 93 case R4: case D4: return 4; 94 case R5: case D5: return 5; 95 case R6: case D6: return 6; 96 case R7: case D7: return 7; 97 case R8: case D8: return 8; 98 case R9: case D9: return 9; 99 case R10: case D10: return 10; 100 case R11: case D11: return 11; 101 case R12: case D12: return 12; 102 case SP: case D13: return 13; 103 case LR: case D14: return 14; 104 case PC: case D15: return 15; 105 106 case S0: case S1: case S2: case S3: 107 case S4: case S5: case S6: case S7: 108 case S8: case S9: case S10: case S11: 109 case S12: case S13: case S14: case S15: 110 case S16: case S17: case S18: case S19: 111 case S20: case S21: case S22: case S23: 112 case S24: case S25: case S26: case S27: 113 case S28: case S29: case S30: case S31: { 114 isSPVFP = true; 115 switch (RegEnum) { 116 default: return 0; // Avoid compile time warning. 117 case S0: return 0; 118 case S1: return 1; 119 case S2: return 2; 120 case S3: return 3; 121 case S4: return 4; 122 case S5: return 5; 123 case S6: return 6; 124 case S7: return 7; 125 case S8: return 8; 126 case S9: return 9; 127 case S10: return 10; 128 case S11: return 11; 129 case S12: return 12; 130 case S13: return 13; 131 case S14: return 14; 132 case S15: return 15; 133 case S16: return 16; 134 case S17: return 17; 135 case S18: return 18; 136 case S19: return 19; 137 case S20: return 20; 138 case S21: return 21; 139 case S22: return 22; 140 case S23: return 23; 141 case S24: return 24; 142 case S25: return 25; 143 case S26: return 26; 144 case S27: return 27; 145 case S28: return 28; 146 case S29: return 29; 147 case S30: return 30; 148 case S31: return 31; 149 } 150 } 151 } 152} 153 154ARMBaseRegisterInfo::ARMBaseRegisterInfo(const ARMBaseInstrInfo &tii, 155 const ARMSubtarget &sti) 156 : ARMGenRegisterInfo(ARM::ADJCALLSTACKDOWN, ARM::ADJCALLSTACKUP), 157 TII(tii), STI(sti), 158 FramePtr((STI.isTargetDarwin() || STI.isThumb()) ? ARM::R7 : ARM::R11) { 159} 160 161unsigned ARMBaseRegisterInfo:: 162getOpcode(int Op) const { 163 return TII.getOpcode((ARMII::Op)Op); 164} 165 166const unsigned* 167ARMBaseRegisterInfo::getCalleeSavedRegs(const MachineFunction *MF) const { 168 static const unsigned CalleeSavedRegs[] = { 169 ARM::LR, ARM::R11, ARM::R10, ARM::R9, ARM::R8, 170 ARM::R7, ARM::R6, ARM::R5, ARM::R4, 171 172 ARM::D15, ARM::D14, ARM::D13, ARM::D12, 173 ARM::D11, ARM::D10, ARM::D9, ARM::D8, 174 0 175 }; 176 177 static const unsigned DarwinCalleeSavedRegs[] = { 178 // Darwin ABI deviates from ARM standard ABI. R9 is not a callee-saved 179 // register. 180 ARM::LR, ARM::R7, ARM::R6, ARM::R5, ARM::R4, 181 ARM::R11, ARM::R10, ARM::R8, 182 183 ARM::D15, ARM::D14, ARM::D13, ARM::D12, 184 ARM::D11, ARM::D10, ARM::D9, ARM::D8, 185 0 186 }; 187 return STI.isTargetDarwin() ? DarwinCalleeSavedRegs : CalleeSavedRegs; 188} 189 190const TargetRegisterClass* const * 191ARMBaseRegisterInfo::getCalleeSavedRegClasses(const MachineFunction *MF) const { 192 static const TargetRegisterClass * const CalleeSavedRegClasses[] = { 193 &ARM::GPRRegClass, &ARM::GPRRegClass, &ARM::GPRRegClass, 194 &ARM::GPRRegClass, &ARM::GPRRegClass, &ARM::GPRRegClass, 195 &ARM::GPRRegClass, &ARM::GPRRegClass, &ARM::GPRRegClass, 196 197 &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass, 198 &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass, 199 0 200 }; 201 202 static const TargetRegisterClass * const ThumbCalleeSavedRegClasses[] = { 203 &ARM::GPRRegClass, &ARM::GPRRegClass, &ARM::GPRRegClass, 204 &ARM::GPRRegClass, &ARM::GPRRegClass, &ARM::tGPRRegClass, 205 &ARM::tGPRRegClass,&ARM::tGPRRegClass,&ARM::tGPRRegClass, 206 207 &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass, 208 &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass, 209 0 210 }; 211 212 static const TargetRegisterClass * const DarwinCalleeSavedRegClasses[] = { 213 &ARM::GPRRegClass, &ARM::GPRRegClass, &ARM::GPRRegClass, 214 &ARM::GPRRegClass, &ARM::GPRRegClass, &ARM::GPRRegClass, 215 &ARM::GPRRegClass, &ARM::GPRRegClass, 216 217 &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass, 218 &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass, 219 0 220 }; 221 222 static const TargetRegisterClass * const DarwinThumbCalleeSavedRegClasses[] ={ 223 &ARM::GPRRegClass, &ARM::tGPRRegClass, &ARM::tGPRRegClass, 224 &ARM::tGPRRegClass, &ARM::tGPRRegClass, &ARM::GPRRegClass, 225 &ARM::GPRRegClass, &ARM::GPRRegClass, 226 227 &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass, 228 &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass, 229 0 230 }; 231 232 if (STI.isThumb1Only()) { 233 return STI.isTargetDarwin() 234 ? DarwinThumbCalleeSavedRegClasses : ThumbCalleeSavedRegClasses; 235 } 236 return STI.isTargetDarwin() 237 ? DarwinCalleeSavedRegClasses : CalleeSavedRegClasses; 238} 239 240BitVector ARMBaseRegisterInfo::getReservedRegs(const MachineFunction &MF) const { 241 // FIXME: avoid re-calculating this everytime. 242 BitVector Reserved(getNumRegs()); 243 Reserved.set(ARM::SP); 244 Reserved.set(ARM::PC); 245 if (STI.isTargetDarwin() || hasFP(MF)) 246 Reserved.set(FramePtr); 247 // Some targets reserve R9. 248 if (STI.isR9Reserved()) 249 Reserved.set(ARM::R9); 250 return Reserved; 251} 252 253bool 254ARMBaseRegisterInfo::isReservedReg(const MachineFunction &MF, unsigned Reg) const { 255 switch (Reg) { 256 default: break; 257 case ARM::SP: 258 case ARM::PC: 259 return true; 260 case ARM::R7: 261 case ARM::R11: 262 if (FramePtr == Reg && (STI.isTargetDarwin() || hasFP(MF))) 263 return true; 264 break; 265 case ARM::R9: 266 return STI.isR9Reserved(); 267 } 268 269 return false; 270} 271 272const TargetRegisterClass *ARMBaseRegisterInfo::getPointerRegClass() const { 273 return &ARM::GPRRegClass; 274} 275 276/// getAllocationOrder - Returns the register allocation order for a specified 277/// register class in the form of a pair of TargetRegisterClass iterators. 278std::pair<TargetRegisterClass::iterator,TargetRegisterClass::iterator> 279ARMBaseRegisterInfo::getAllocationOrder(const TargetRegisterClass *RC, 280 unsigned HintType, unsigned HintReg, 281 const MachineFunction &MF) const { 282 // Alternative register allocation orders when favoring even / odd registers 283 // of register pairs. 284 285 // No FP, R9 is available. 286 static const unsigned GPREven1[] = { 287 ARM::R0, ARM::R2, ARM::R4, ARM::R6, ARM::R8, ARM::R10, 288 ARM::R1, ARM::R3, ARM::R12,ARM::LR, ARM::R5, ARM::R7, 289 ARM::R9, ARM::R11 290 }; 291 static const unsigned GPROdd1[] = { 292 ARM::R1, ARM::R3, ARM::R5, ARM::R7, ARM::R9, ARM::R11, 293 ARM::R0, ARM::R2, ARM::R12,ARM::LR, ARM::R4, ARM::R6, 294 ARM::R8, ARM::R10 295 }; 296 297 // FP is R7, R9 is available. 298 static const unsigned GPREven2[] = { 299 ARM::R0, ARM::R2, ARM::R4, ARM::R8, ARM::R10, 300 ARM::R1, ARM::R3, ARM::R12,ARM::LR, ARM::R5, ARM::R6, 301 ARM::R9, ARM::R11 302 }; 303 static const unsigned GPROdd2[] = { 304 ARM::R1, ARM::R3, ARM::R5, ARM::R9, ARM::R11, 305 ARM::R0, ARM::R2, ARM::R12,ARM::LR, ARM::R4, ARM::R6, 306 ARM::R8, ARM::R10 307 }; 308 309 // FP is R11, R9 is available. 310 static const unsigned GPREven3[] = { 311 ARM::R0, ARM::R2, ARM::R4, ARM::R6, ARM::R8, 312 ARM::R1, ARM::R3, ARM::R10,ARM::R12,ARM::LR, ARM::R5, ARM::R7, 313 ARM::R9 314 }; 315 static const unsigned GPROdd3[] = { 316 ARM::R1, ARM::R3, ARM::R5, ARM::R6, ARM::R9, 317 ARM::R0, ARM::R2, ARM::R10,ARM::R12,ARM::LR, ARM::R4, ARM::R7, 318 ARM::R8 319 }; 320 321 // No FP, R9 is not available. 322 static const unsigned GPREven4[] = { 323 ARM::R0, ARM::R2, ARM::R4, ARM::R6, ARM::R10, 324 ARM::R1, ARM::R3, ARM::R12,ARM::LR, ARM::R5, ARM::R7, ARM::R8, 325 ARM::R11 326 }; 327 static const unsigned GPROdd4[] = { 328 ARM::R1, ARM::R3, ARM::R5, ARM::R7, ARM::R11, 329 ARM::R0, ARM::R2, ARM::R12,ARM::LR, ARM::R4, ARM::R6, ARM::R8, 330 ARM::R10 331 }; 332 333 // FP is R7, R9 is not available. 334 static const unsigned GPREven5[] = { 335 ARM::R0, ARM::R2, ARM::R4, ARM::R10, 336 ARM::R1, ARM::R3, ARM::R12,ARM::LR, ARM::R5, ARM::R6, ARM::R8, 337 ARM::R11 338 }; 339 static const unsigned GPROdd5[] = { 340 ARM::R1, ARM::R3, ARM::R5, ARM::R11, 341 ARM::R0, ARM::R2, ARM::R12,ARM::LR, ARM::R4, ARM::R6, ARM::R8, 342 ARM::R10 343 }; 344 345 // FP is R11, R9 is not available. 346 static const unsigned GPREven6[] = { 347 ARM::R0, ARM::R2, ARM::R4, ARM::R6, 348 ARM::R1, ARM::R3, ARM::R10,ARM::R12,ARM::LR, ARM::R5, ARM::R7, ARM::R8 349 }; 350 static const unsigned GPROdd6[] = { 351 ARM::R1, ARM::R3, ARM::R5, ARM::R7, 352 ARM::R0, ARM::R2, ARM::R10,ARM::R12,ARM::LR, ARM::R4, ARM::R6, ARM::R8 353 }; 354 355 356 if (HintType == ARMRI::RegPairEven) { 357 if (isPhysicalRegister(HintReg) && getRegisterPairEven(HintReg, MF) == 0) 358 // It's no longer possible to fulfill this hint. Return the default 359 // allocation order. 360 return std::make_pair(RC->allocation_order_begin(MF), 361 RC->allocation_order_end(MF)); 362 363 if (!STI.isTargetDarwin() && !hasFP(MF)) { 364 if (!STI.isR9Reserved()) 365 return std::make_pair(GPREven1, 366 GPREven1 + (sizeof(GPREven1)/sizeof(unsigned))); 367 else 368 return std::make_pair(GPREven4, 369 GPREven4 + (sizeof(GPREven4)/sizeof(unsigned))); 370 } else if (FramePtr == ARM::R7) { 371 if (!STI.isR9Reserved()) 372 return std::make_pair(GPREven2, 373 GPREven2 + (sizeof(GPREven2)/sizeof(unsigned))); 374 else 375 return std::make_pair(GPREven5, 376 GPREven5 + (sizeof(GPREven5)/sizeof(unsigned))); 377 } else { // FramePtr == ARM::R11 378 if (!STI.isR9Reserved()) 379 return std::make_pair(GPREven3, 380 GPREven3 + (sizeof(GPREven3)/sizeof(unsigned))); 381 else 382 return std::make_pair(GPREven6, 383 GPREven6 + (sizeof(GPREven6)/sizeof(unsigned))); 384 } 385 } else if (HintType == ARMRI::RegPairOdd) { 386 if (isPhysicalRegister(HintReg) && getRegisterPairOdd(HintReg, MF) == 0) 387 // It's no longer possible to fulfill this hint. Return the default 388 // allocation order. 389 return std::make_pair(RC->allocation_order_begin(MF), 390 RC->allocation_order_end(MF)); 391 392 if (!STI.isTargetDarwin() && !hasFP(MF)) { 393 if (!STI.isR9Reserved()) 394 return std::make_pair(GPROdd1, 395 GPROdd1 + (sizeof(GPROdd1)/sizeof(unsigned))); 396 else 397 return std::make_pair(GPROdd4, 398 GPROdd4 + (sizeof(GPROdd4)/sizeof(unsigned))); 399 } else if (FramePtr == ARM::R7) { 400 if (!STI.isR9Reserved()) 401 return std::make_pair(GPROdd2, 402 GPROdd2 + (sizeof(GPROdd2)/sizeof(unsigned))); 403 else 404 return std::make_pair(GPROdd5, 405 GPROdd5 + (sizeof(GPROdd5)/sizeof(unsigned))); 406 } else { // FramePtr == ARM::R11 407 if (!STI.isR9Reserved()) 408 return std::make_pair(GPROdd3, 409 GPROdd3 + (sizeof(GPROdd3)/sizeof(unsigned))); 410 else 411 return std::make_pair(GPROdd6, 412 GPROdd6 + (sizeof(GPROdd6)/sizeof(unsigned))); 413 } 414 } 415 return std::make_pair(RC->allocation_order_begin(MF), 416 RC->allocation_order_end(MF)); 417} 418 419/// ResolveRegAllocHint - Resolves the specified register allocation hint 420/// to a physical register. Returns the physical register if it is successful. 421unsigned 422ARMBaseRegisterInfo::ResolveRegAllocHint(unsigned Type, unsigned Reg, 423 const MachineFunction &MF) const { 424 if (Reg == 0 || !isPhysicalRegister(Reg)) 425 return 0; 426 if (Type == 0) 427 return Reg; 428 else if (Type == (unsigned)ARMRI::RegPairOdd) 429 // Odd register. 430 return getRegisterPairOdd(Reg, MF); 431 else if (Type == (unsigned)ARMRI::RegPairEven) 432 // Even register. 433 return getRegisterPairEven(Reg, MF); 434 return 0; 435} 436 437void 438ARMBaseRegisterInfo::UpdateRegAllocHint(unsigned Reg, unsigned NewReg, 439 MachineFunction &MF) const { 440 MachineRegisterInfo *MRI = &MF.getRegInfo(); 441 std::pair<unsigned, unsigned> Hint = MRI->getRegAllocationHint(Reg); 442 if ((Hint.first == (unsigned)ARMRI::RegPairOdd || 443 Hint.first == (unsigned)ARMRI::RegPairEven) && 444 Hint.second && TargetRegisterInfo::isVirtualRegister(Hint.second)) { 445 // If 'Reg' is one of the even / odd register pair and it's now changed 446 // (e.g. coalesced) into a different register. The other register of the 447 // pair allocation hint must be updated to reflect the relationship 448 // change. 449 unsigned OtherReg = Hint.second; 450 Hint = MRI->getRegAllocationHint(OtherReg); 451 if (Hint.second == Reg) 452 // Make sure the pair has not already divorced. 453 MRI->setRegAllocationHint(OtherReg, Hint.first, NewReg); 454 } 455} 456 457/// hasFP - Return true if the specified function should have a dedicated frame 458/// pointer register. This is true if the function has variable sized allocas 459/// or if frame pointer elimination is disabled. 460/// 461bool ARMBaseRegisterInfo::hasFP(const MachineFunction &MF) const { 462 const MachineFrameInfo *MFI = MF.getFrameInfo(); 463 return (NoFramePointerElim || 464 MFI->hasVarSizedObjects() || 465 MFI->isFrameAddressTaken()); 466} 467 468static unsigned estimateStackSize(MachineFunction &MF, MachineFrameInfo *MFI) { 469 const MachineFrameInfo *FFI = MF.getFrameInfo(); 470 int Offset = 0; 471 for (int i = FFI->getObjectIndexBegin(); i != 0; ++i) { 472 int FixedOff = -FFI->getObjectOffset(i); 473 if (FixedOff > Offset) Offset = FixedOff; 474 } 475 for (unsigned i = 0, e = FFI->getObjectIndexEnd(); i != e; ++i) { 476 if (FFI->isDeadObjectIndex(i)) 477 continue; 478 Offset += FFI->getObjectSize(i); 479 unsigned Align = FFI->getObjectAlignment(i); 480 // Adjust to alignment boundary 481 Offset = (Offset+Align-1)/Align*Align; 482 } 483 return (unsigned)Offset; 484} 485 486void 487ARMBaseRegisterInfo::processFunctionBeforeCalleeSavedScan(MachineFunction &MF, 488 RegScavenger *RS) const { 489 // This tells PEI to spill the FP as if it is any other callee-save register 490 // to take advantage the eliminateFrameIndex machinery. This also ensures it 491 // is spilled in the order specified by getCalleeSavedRegs() to make it easier 492 // to combine multiple loads / stores. 493 bool CanEliminateFrame = true; 494 bool CS1Spilled = false; 495 bool LRSpilled = false; 496 unsigned NumGPRSpills = 0; 497 SmallVector<unsigned, 4> UnspilledCS1GPRs; 498 SmallVector<unsigned, 4> UnspilledCS2GPRs; 499 ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>(); 500 501 // Don't spill FP if the frame can be eliminated. This is determined 502 // by scanning the callee-save registers to see if any is used. 503 const unsigned *CSRegs = getCalleeSavedRegs(); 504 const TargetRegisterClass* const *CSRegClasses = getCalleeSavedRegClasses(); 505 for (unsigned i = 0; CSRegs[i]; ++i) { 506 unsigned Reg = CSRegs[i]; 507 bool Spilled = false; 508 if (MF.getRegInfo().isPhysRegUsed(Reg)) { 509 AFI->setCSRegisterIsSpilled(Reg); 510 Spilled = true; 511 CanEliminateFrame = false; 512 } else { 513 // Check alias registers too. 514 for (const unsigned *Aliases = getAliasSet(Reg); *Aliases; ++Aliases) { 515 if (MF.getRegInfo().isPhysRegUsed(*Aliases)) { 516 Spilled = true; 517 CanEliminateFrame = false; 518 } 519 } 520 } 521 522 if (CSRegClasses[i] == &ARM::GPRRegClass) { 523 if (Spilled) { 524 NumGPRSpills++; 525 526 if (!STI.isTargetDarwin()) { 527 if (Reg == ARM::LR) 528 LRSpilled = true; 529 CS1Spilled = true; 530 continue; 531 } 532 533 // Keep track if LR and any of R4, R5, R6, and R7 is spilled. 534 switch (Reg) { 535 case ARM::LR: 536 LRSpilled = true; 537 // Fallthrough 538 case ARM::R4: 539 case ARM::R5: 540 case ARM::R6: 541 case ARM::R7: 542 CS1Spilled = true; 543 break; 544 default: 545 break; 546 } 547 } else { 548 if (!STI.isTargetDarwin()) { 549 UnspilledCS1GPRs.push_back(Reg); 550 continue; 551 } 552 553 switch (Reg) { 554 case ARM::R4: 555 case ARM::R5: 556 case ARM::R6: 557 case ARM::R7: 558 case ARM::LR: 559 UnspilledCS1GPRs.push_back(Reg); 560 break; 561 default: 562 UnspilledCS2GPRs.push_back(Reg); 563 break; 564 } 565 } 566 } 567 } 568 569 bool ForceLRSpill = false; 570 if (!LRSpilled && AFI->isThumb1OnlyFunction()) { 571 unsigned FnSize = TII.GetFunctionSizeInBytes(MF); 572 // Force LR to be spilled if the Thumb function size is > 2048. This enables 573 // use of BL to implement far jump. If it turns out that it's not needed 574 // then the branch fix up path will undo it. 575 if (FnSize >= (1 << 11)) { 576 CanEliminateFrame = false; 577 ForceLRSpill = true; 578 } 579 } 580 581 bool ExtraCSSpill = false; 582 if (!CanEliminateFrame || hasFP(MF)) { 583 AFI->setHasStackFrame(true); 584 585 // If LR is not spilled, but at least one of R4, R5, R6, and R7 is spilled. 586 // Spill LR as well so we can fold BX_RET to the registers restore (LDM). 587 if (!LRSpilled && CS1Spilled) { 588 MF.getRegInfo().setPhysRegUsed(ARM::LR); 589 AFI->setCSRegisterIsSpilled(ARM::LR); 590 NumGPRSpills++; 591 UnspilledCS1GPRs.erase(std::find(UnspilledCS1GPRs.begin(), 592 UnspilledCS1GPRs.end(), (unsigned)ARM::LR)); 593 ForceLRSpill = false; 594 ExtraCSSpill = true; 595 } 596 597 // Darwin ABI requires FP to point to the stack slot that contains the 598 // previous FP. 599 if (STI.isTargetDarwin() || hasFP(MF)) { 600 MF.getRegInfo().setPhysRegUsed(FramePtr); 601 NumGPRSpills++; 602 } 603 604 // If stack and double are 8-byte aligned and we are spilling an odd number 605 // of GPRs. Spill one extra callee save GPR so we won't have to pad between 606 // the integer and double callee save areas. 607 unsigned TargetAlign = MF.getTarget().getFrameInfo()->getStackAlignment(); 608 if (TargetAlign == 8 && (NumGPRSpills & 1)) { 609 if (CS1Spilled && !UnspilledCS1GPRs.empty()) { 610 for (unsigned i = 0, e = UnspilledCS1GPRs.size(); i != e; ++i) { 611 unsigned Reg = UnspilledCS1GPRs[i]; 612 // Don't spill high register if the function is thumb1 613 if (!AFI->isThumb1OnlyFunction() || 614 isARMLowRegister(Reg) || Reg == ARM::LR) { 615 MF.getRegInfo().setPhysRegUsed(Reg); 616 AFI->setCSRegisterIsSpilled(Reg); 617 if (!isReservedReg(MF, Reg)) 618 ExtraCSSpill = true; 619 break; 620 } 621 } 622 } else if (!UnspilledCS2GPRs.empty() && 623 !AFI->isThumb1OnlyFunction()) { 624 unsigned Reg = UnspilledCS2GPRs.front(); 625 MF.getRegInfo().setPhysRegUsed(Reg); 626 AFI->setCSRegisterIsSpilled(Reg); 627 if (!isReservedReg(MF, Reg)) 628 ExtraCSSpill = true; 629 } 630 } 631 632 // Estimate if we might need to scavenge a register at some point in order 633 // to materialize a stack offset. If so, either spill one additional 634 // callee-saved register or reserve a special spill slot to facilitate 635 // register scavenging. 636 if (RS && !ExtraCSSpill && !AFI->isThumb1OnlyFunction()) { 637 MachineFrameInfo *MFI = MF.getFrameInfo(); 638 unsigned Size = estimateStackSize(MF, MFI); 639 unsigned Limit = (1 << 12) - 1; 640 for (MachineFunction::iterator BB = MF.begin(),E = MF.end();BB != E; ++BB) 641 for (MachineBasicBlock::iterator I= BB->begin(); I != BB->end(); ++I) { 642 for (unsigned i = 0, e = I->getNumOperands(); i != e; ++i) 643 if (I->getOperand(i).isFI()) { 644 unsigned Opcode = I->getOpcode(); 645 const TargetInstrDesc &Desc = TII.get(Opcode); 646 unsigned AddrMode = (Desc.TSFlags & ARMII::AddrModeMask); 647 if (AddrMode == ARMII::AddrMode3) { 648 Limit = (1 << 8) - 1; 649 goto DoneEstimating; 650 } else if (AddrMode == ARMII::AddrMode5) { 651 unsigned ThisLimit = ((1 << 8) - 1) * 4; 652 if (ThisLimit < Limit) 653 Limit = ThisLimit; 654 } 655 } 656 } 657 DoneEstimating: 658 if (Size >= Limit) { 659 // If any non-reserved CS register isn't spilled, just spill one or two 660 // extra. That should take care of it! 661 unsigned NumExtras = TargetAlign / 4; 662 SmallVector<unsigned, 2> Extras; 663 while (NumExtras && !UnspilledCS1GPRs.empty()) { 664 unsigned Reg = UnspilledCS1GPRs.back(); 665 UnspilledCS1GPRs.pop_back(); 666 if (!isReservedReg(MF, Reg)) { 667 Extras.push_back(Reg); 668 NumExtras--; 669 } 670 } 671 while (NumExtras && !UnspilledCS2GPRs.empty()) { 672 unsigned Reg = UnspilledCS2GPRs.back(); 673 UnspilledCS2GPRs.pop_back(); 674 if (!isReservedReg(MF, Reg)) { 675 Extras.push_back(Reg); 676 NumExtras--; 677 } 678 } 679 if (Extras.size() && NumExtras == 0) { 680 for (unsigned i = 0, e = Extras.size(); i != e; ++i) { 681 MF.getRegInfo().setPhysRegUsed(Extras[i]); 682 AFI->setCSRegisterIsSpilled(Extras[i]); 683 } 684 } else { 685 // Reserve a slot closest to SP or frame pointer. 686 const TargetRegisterClass *RC = &ARM::GPRRegClass; 687 RS->setScavengingFrameIndex(MFI->CreateStackObject(RC->getSize(), 688 RC->getAlignment())); 689 } 690 } 691 } 692 } 693 694 if (ForceLRSpill) { 695 MF.getRegInfo().setPhysRegUsed(ARM::LR); 696 AFI->setCSRegisterIsSpilled(ARM::LR); 697 AFI->setLRIsSpilledForFarJump(true); 698 } 699} 700 701unsigned ARMBaseRegisterInfo::getRARegister() const { 702 return ARM::LR; 703} 704 705unsigned ARMBaseRegisterInfo::getFrameRegister(MachineFunction &MF) const { 706 if (STI.isTargetDarwin() || hasFP(MF)) 707 return FramePtr; 708 return ARM::SP; 709} 710 711unsigned ARMBaseRegisterInfo::getEHExceptionRegister() const { 712 llvm_unreachable("What is the exception register"); 713 return 0; 714} 715 716unsigned ARMBaseRegisterInfo::getEHHandlerRegister() const { 717 llvm_unreachable("What is the exception handler register"); 718 return 0; 719} 720 721int ARMBaseRegisterInfo::getDwarfRegNum(unsigned RegNum, bool isEH) const { 722 return ARMGenRegisterInfo::getDwarfRegNumFull(RegNum, 0); 723} 724 725unsigned ARMBaseRegisterInfo::getRegisterPairEven(unsigned Reg, 726 const MachineFunction &MF) const { 727 switch (Reg) { 728 default: break; 729 // Return 0 if either register of the pair is a special register. 730 // So no R12, etc. 731 case ARM::R1: 732 return ARM::R0; 733 case ARM::R3: 734 // FIXME! 735 return STI.isThumb1Only() ? 0 : ARM::R2; 736 case ARM::R5: 737 return ARM::R4; 738 case ARM::R7: 739 return isReservedReg(MF, ARM::R7) ? 0 : ARM::R6; 740 case ARM::R9: 741 return isReservedReg(MF, ARM::R9) ? 0 :ARM::R8; 742 case ARM::R11: 743 return isReservedReg(MF, ARM::R11) ? 0 : ARM::R10; 744 745 case ARM::S1: 746 return ARM::S0; 747 case ARM::S3: 748 return ARM::S2; 749 case ARM::S5: 750 return ARM::S4; 751 case ARM::S7: 752 return ARM::S6; 753 case ARM::S9: 754 return ARM::S8; 755 case ARM::S11: 756 return ARM::S10; 757 case ARM::S13: 758 return ARM::S12; 759 case ARM::S15: 760 return ARM::S14; 761 case ARM::S17: 762 return ARM::S16; 763 case ARM::S19: 764 return ARM::S18; 765 case ARM::S21: 766 return ARM::S20; 767 case ARM::S23: 768 return ARM::S22; 769 case ARM::S25: 770 return ARM::S24; 771 case ARM::S27: 772 return ARM::S26; 773 case ARM::S29: 774 return ARM::S28; 775 case ARM::S31: 776 return ARM::S30; 777 778 case ARM::D1: 779 return ARM::D0; 780 case ARM::D3: 781 return ARM::D2; 782 case ARM::D5: 783 return ARM::D4; 784 case ARM::D7: 785 return ARM::D6; 786 case ARM::D9: 787 return ARM::D8; 788 case ARM::D11: 789 return ARM::D10; 790 case ARM::D13: 791 return ARM::D12; 792 case ARM::D15: 793 return ARM::D14; 794 } 795 796 return 0; 797} 798 799unsigned ARMBaseRegisterInfo::getRegisterPairOdd(unsigned Reg, 800 const MachineFunction &MF) const { 801 switch (Reg) { 802 default: break; 803 // Return 0 if either register of the pair is a special register. 804 // So no R12, etc. 805 case ARM::R0: 806 return ARM::R1; 807 case ARM::R2: 808 // FIXME! 809 return STI.isThumb1Only() ? 0 : ARM::R3; 810 case ARM::R4: 811 return ARM::R5; 812 case ARM::R6: 813 return isReservedReg(MF, ARM::R7) ? 0 : ARM::R7; 814 case ARM::R8: 815 return isReservedReg(MF, ARM::R9) ? 0 :ARM::R9; 816 case ARM::R10: 817 return isReservedReg(MF, ARM::R11) ? 0 : ARM::R11; 818 819 case ARM::S0: 820 return ARM::S1; 821 case ARM::S2: 822 return ARM::S3; 823 case ARM::S4: 824 return ARM::S5; 825 case ARM::S6: 826 return ARM::S7; 827 case ARM::S8: 828 return ARM::S9; 829 case ARM::S10: 830 return ARM::S11; 831 case ARM::S12: 832 return ARM::S13; 833 case ARM::S14: 834 return ARM::S15; 835 case ARM::S16: 836 return ARM::S17; 837 case ARM::S18: 838 return ARM::S19; 839 case ARM::S20: 840 return ARM::S21; 841 case ARM::S22: 842 return ARM::S23; 843 case ARM::S24: 844 return ARM::S25; 845 case ARM::S26: 846 return ARM::S27; 847 case ARM::S28: 848 return ARM::S29; 849 case ARM::S30: 850 return ARM::S31; 851 852 case ARM::D0: 853 return ARM::D1; 854 case ARM::D2: 855 return ARM::D3; 856 case ARM::D4: 857 return ARM::D5; 858 case ARM::D6: 859 return ARM::D7; 860 case ARM::D8: 861 return ARM::D9; 862 case ARM::D10: 863 return ARM::D11; 864 case ARM::D12: 865 return ARM::D13; 866 case ARM::D14: 867 return ARM::D15; 868 } 869 870 return 0; 871} 872 873// FIXME: Dup in ARMBaseInstrInfo.cpp 874static inline 875const MachineInstrBuilder &AddDefaultPred(const MachineInstrBuilder &MIB) { 876 return MIB.addImm((int64_t)ARMCC::AL).addReg(0); 877} 878 879static inline 880const MachineInstrBuilder &AddDefaultCC(const MachineInstrBuilder &MIB) { 881 return MIB.addReg(0); 882} 883 884/// emitLoadConstPool - Emits a load from constpool to materialize the 885/// specified immediate. 886void ARMBaseRegisterInfo:: 887emitLoadConstPool(MachineBasicBlock &MBB, 888 MachineBasicBlock::iterator &MBBI, 889 DebugLoc dl, 890 unsigned DestReg, unsigned SubIdx, int Val, 891 ARMCC::CondCodes Pred, 892 unsigned PredReg) const { 893 MachineFunction &MF = *MBB.getParent(); 894 MachineConstantPool *ConstantPool = MF.getConstantPool(); 895 Constant *C = 896 MF.getFunction()->getContext().getConstantInt(Type::Int32Ty, Val); 897 unsigned Idx = ConstantPool->getConstantPoolIndex(C, 4); 898 899 BuildMI(MBB, MBBI, dl, TII.get(ARM::LDRcp)) 900 .addReg(DestReg, getDefRegState(true), SubIdx) 901 .addConstantPoolIndex(Idx) 902 .addReg(0).addImm(0).addImm(Pred).addReg(PredReg); 903} 904 905bool ARMBaseRegisterInfo:: 906requiresRegisterScavenging(const MachineFunction &MF) const { 907 return true; 908} 909 910// hasReservedCallFrame - Under normal circumstances, when a frame pointer is 911// not required, we reserve argument space for call sites in the function 912// immediately on entry to the current function. This eliminates the need for 913// add/sub sp brackets around call sites. Returns true if the call frame is 914// included as part of the stack frame. 915bool ARMBaseRegisterInfo:: 916hasReservedCallFrame(MachineFunction &MF) const { 917 const MachineFrameInfo *FFI = MF.getFrameInfo(); 918 unsigned CFSize = FFI->getMaxCallFrameSize(); 919 // It's not always a good idea to include the call frame as part of the 920 // stack frame. ARM (especially Thumb) has small immediate offset to 921 // address the stack frame. So a large call frame can cause poor codegen 922 // and may even makes it impossible to scavenge a register. 923 if (CFSize >= ((1 << 12) - 1) / 2) // Half of imm12 924 return false; 925 926 return !MF.getFrameInfo()->hasVarSizedObjects(); 927} 928 929/// emitARMRegPlusImmediate - Emits a series of instructions to materialize 930/// a destreg = basereg + immediate in ARM code. 931static 932void emitARMRegPlusImmediate(MachineBasicBlock &MBB, 933 MachineBasicBlock::iterator &MBBI, 934 unsigned DestReg, unsigned BaseReg, int NumBytes, 935 ARMCC::CondCodes Pred, unsigned PredReg, 936 const ARMBaseInstrInfo &TII, 937 DebugLoc dl) { 938 bool isSub = NumBytes < 0; 939 if (isSub) NumBytes = -NumBytes; 940 941 while (NumBytes) { 942 unsigned RotAmt = ARM_AM::getSOImmValRotate(NumBytes); 943 unsigned ThisVal = NumBytes & ARM_AM::rotr32(0xFF, RotAmt); 944 assert(ThisVal && "Didn't extract field correctly"); 945 946 // We will handle these bits from offset, clear them. 947 NumBytes &= ~ThisVal; 948 949 assert(ARM_AM::getSOImmVal(ThisVal) != -1 && "Bit extraction didn't work?"); 950 951 // Build the new ADD / SUB. 952 BuildMI(MBB, MBBI, dl, TII.get(TII.getOpcode(isSub ? ARMII::SUBri : ARMII::ADDri)), DestReg) 953 .addReg(BaseReg, RegState::Kill).addImm(ThisVal) 954 .addImm((unsigned)Pred).addReg(PredReg).addReg(0); 955 BaseReg = DestReg; 956 } 957} 958 959static void 960emitSPUpdate(MachineBasicBlock &MBB, MachineBasicBlock::iterator &MBBI, 961 const ARMBaseInstrInfo &TII, DebugLoc dl, 962 int NumBytes, 963 ARMCC::CondCodes Pred = ARMCC::AL, unsigned PredReg = 0) { 964 emitARMRegPlusImmediate(MBB, MBBI, ARM::SP, ARM::SP, NumBytes, 965 Pred, PredReg, TII, dl); 966} 967 968void ARMBaseRegisterInfo:: 969eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB, 970 MachineBasicBlock::iterator I) const { 971 if (!hasReservedCallFrame(MF)) { 972 // If we have alloca, convert as follows: 973 // ADJCALLSTACKDOWN -> sub, sp, sp, amount 974 // ADJCALLSTACKUP -> add, sp, sp, amount 975 MachineInstr *Old = I; 976 DebugLoc dl = Old->getDebugLoc(); 977 unsigned Amount = Old->getOperand(0).getImm(); 978 if (Amount != 0) { 979 // We need to keep the stack aligned properly. To do this, we round the 980 // amount of space needed for the outgoing arguments up to the next 981 // alignment boundary. 982 unsigned Align = MF.getTarget().getFrameInfo()->getStackAlignment(); 983 Amount = (Amount+Align-1)/Align*Align; 984 985 // Replace the pseudo instruction with a new instruction... 986 unsigned Opc = Old->getOpcode(); 987 ARMCC::CondCodes Pred = (ARMCC::CondCodes)Old->getOperand(1).getImm(); 988 if (Opc == ARM::ADJCALLSTACKDOWN || Opc == ARM::tADJCALLSTACKDOWN) { 989 // Note: PredReg is operand 2 for ADJCALLSTACKDOWN. 990 unsigned PredReg = Old->getOperand(2).getReg(); 991 emitSPUpdate(MBB, I, TII, dl, -Amount, Pred, PredReg); 992 } else { 993 // Note: PredReg is operand 3 for ADJCALLSTACKUP. 994 unsigned PredReg = Old->getOperand(3).getReg(); 995 assert(Opc == ARM::ADJCALLSTACKUP || Opc == ARM::tADJCALLSTACKUP); 996 emitSPUpdate(MBB, I, TII, dl, Amount, Pred, PredReg); 997 } 998 } 999 } 1000 MBB.erase(I); 1001} 1002 1003/// findScratchRegister - Find a 'free' ARM register. If register scavenger 1004/// is not being used, R12 is available. Otherwise, try for a call-clobbered 1005/// register first and then a spilled callee-saved register if that fails. 1006static 1007unsigned findScratchRegister(RegScavenger *RS, const TargetRegisterClass *RC, 1008 ARMFunctionInfo *AFI) { 1009 unsigned Reg = RS ? RS->FindUnusedReg(RC, true) : (unsigned) ARM::R12; 1010 assert (!AFI->isThumb1OnlyFunction()); 1011 if (Reg == 0) 1012 // Try a already spilled CS register. 1013 Reg = RS->FindUnusedReg(RC, AFI->getSpilledCSRegisters()); 1014 1015 return Reg; 1016} 1017 1018void ARMBaseRegisterInfo:: 1019eliminateFrameIndex(MachineBasicBlock::iterator II, 1020 int SPAdj, RegScavenger *RS) const{ 1021 unsigned i = 0; 1022 MachineInstr &MI = *II; 1023 MachineBasicBlock &MBB = *MI.getParent(); 1024 MachineFunction &MF = *MBB.getParent(); 1025 ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>(); 1026 DebugLoc dl = MI.getDebugLoc(); 1027 1028 while (!MI.getOperand(i).isFI()) { 1029 ++i; 1030 assert(i < MI.getNumOperands() && "Instr doesn't have FrameIndex operand!"); 1031 } 1032 1033 unsigned FrameReg = ARM::SP; 1034 int FrameIndex = MI.getOperand(i).getIndex(); 1035 int Offset = MF.getFrameInfo()->getObjectOffset(FrameIndex) + 1036 MF.getFrameInfo()->getStackSize() + SPAdj; 1037 1038 if (AFI->isGPRCalleeSavedArea1Frame(FrameIndex)) 1039 Offset -= AFI->getGPRCalleeSavedArea1Offset(); 1040 else if (AFI->isGPRCalleeSavedArea2Frame(FrameIndex)) 1041 Offset -= AFI->getGPRCalleeSavedArea2Offset(); 1042 else if (AFI->isDPRCalleeSavedAreaFrame(FrameIndex)) 1043 Offset -= AFI->getDPRCalleeSavedAreaOffset(); 1044 else if (hasFP(MF)) { 1045 assert(SPAdj == 0 && "Unexpected"); 1046 // There is alloca()'s in this function, must reference off the frame 1047 // pointer instead. 1048 FrameReg = getFrameRegister(MF); 1049 Offset -= AFI->getFramePtrSpillOffset(); 1050 } 1051 1052 unsigned Opcode = MI.getOpcode(); 1053 const TargetInstrDesc &Desc = MI.getDesc(); 1054 unsigned AddrMode = (Desc.TSFlags & ARMII::AddrModeMask); 1055 bool isSub = false; 1056 1057 // Memory operands in inline assembly always use AddrMode2. 1058 if (Opcode == ARM::INLINEASM) 1059 AddrMode = ARMII::AddrMode2; 1060 1061 if (Opcode == getOpcode(ARMII::ADDri)) { 1062 Offset += MI.getOperand(i+1).getImm(); 1063 if (Offset == 0) { 1064 // Turn it into a move. 1065 MI.setDesc(TII.get(getOpcode(ARMII::MOVr))); 1066 MI.getOperand(i).ChangeToRegister(FrameReg, false); 1067 MI.RemoveOperand(i+1); 1068 return; 1069 } else if (Offset < 0) { 1070 Offset = -Offset; 1071 isSub = true; 1072 MI.setDesc(TII.get(getOpcode(ARMII::SUBri))); 1073 } 1074 1075 // Common case: small offset, fits into instruction. 1076 if (ARM_AM::getSOImmVal(Offset) != -1) { 1077 // Replace the FrameIndex with sp / fp 1078 MI.getOperand(i).ChangeToRegister(FrameReg, false); 1079 MI.getOperand(i+1).ChangeToImmediate(Offset); 1080 return; 1081 } 1082 1083 // Otherwise, we fallback to common code below to form the imm offset with 1084 // a sequence of ADDri instructions. First though, pull as much of the imm 1085 // into this ADDri as possible. 1086 unsigned RotAmt = ARM_AM::getSOImmValRotate(Offset); 1087 unsigned ThisImmVal = Offset & ARM_AM::rotr32(0xFF, RotAmt); 1088 1089 // We will handle these bits from offset, clear them. 1090 Offset &= ~ThisImmVal; 1091 1092 // Get the properly encoded SOImmVal field. 1093 assert(ARM_AM::getSOImmVal(ThisImmVal) != -1 && 1094 "Bit extraction didn't work?"); 1095 MI.getOperand(i+1).ChangeToImmediate(ThisImmVal); 1096 } else { 1097 unsigned ImmIdx = 0; 1098 int InstrOffs = 0; 1099 unsigned NumBits = 0; 1100 unsigned Scale = 1; 1101 switch (AddrMode) { 1102 case ARMII::AddrMode2: { 1103 ImmIdx = i+2; 1104 InstrOffs = ARM_AM::getAM2Offset(MI.getOperand(ImmIdx).getImm()); 1105 if (ARM_AM::getAM2Op(MI.getOperand(ImmIdx).getImm()) == ARM_AM::sub) 1106 InstrOffs *= -1; 1107 NumBits = 12; 1108 break; 1109 } 1110 case ARMII::AddrMode3: { 1111 ImmIdx = i+2; 1112 InstrOffs = ARM_AM::getAM3Offset(MI.getOperand(ImmIdx).getImm()); 1113 if (ARM_AM::getAM3Op(MI.getOperand(ImmIdx).getImm()) == ARM_AM::sub) 1114 InstrOffs *= -1; 1115 NumBits = 8; 1116 break; 1117 } 1118 case ARMII::AddrMode5: { 1119 ImmIdx = i+1; 1120 InstrOffs = ARM_AM::getAM5Offset(MI.getOperand(ImmIdx).getImm()); 1121 if (ARM_AM::getAM5Op(MI.getOperand(ImmIdx).getImm()) == ARM_AM::sub) 1122 InstrOffs *= -1; 1123 NumBits = 8; 1124 Scale = 4; 1125 break; 1126 } 1127 case ARMII::AddrModeT2_i12: { 1128 ImmIdx = i+1; 1129 InstrOffs = MI.getOperand(ImmIdx).getImm(); 1130 NumBits = 12; 1131 break; 1132 } 1133 case ARMII::AddrModeT2_i8: { 1134 ImmIdx = i+1; 1135 InstrOffs = MI.getOperand(ImmIdx).getImm(); 1136 NumBits = 8; 1137 break; 1138 } 1139 case ARMII::AddrModeT2_so: { 1140 ImmIdx = i+2; 1141 InstrOffs = MI.getOperand(ImmIdx).getImm(); 1142 break; 1143 } 1144 default: 1145 llvm_unreachable("Unsupported addressing mode!"); 1146 break; 1147 } 1148 1149 Offset += InstrOffs * Scale; 1150 assert((Offset & (Scale-1)) == 0 && "Can't encode this offset!"); 1151 if (Offset < 0) { 1152 Offset = -Offset; 1153 isSub = true; 1154 } 1155 1156 // Common case: small offset, fits into instruction. 1157 MachineOperand &ImmOp = MI.getOperand(ImmIdx); 1158 int ImmedOffset = Offset / Scale; 1159 unsigned Mask = (1 << NumBits) - 1; 1160 if ((unsigned)Offset <= Mask * Scale) { 1161 // Replace the FrameIndex with sp 1162 MI.getOperand(i).ChangeToRegister(FrameReg, false); 1163 if (isSub) 1164 ImmedOffset |= 1 << NumBits; 1165 ImmOp.ChangeToImmediate(ImmedOffset); 1166 return; 1167 } 1168 1169 // Otherwise, it didn't fit. Pull in what we can to simplify the immed. 1170 ImmedOffset = ImmedOffset & Mask; 1171 if (isSub) 1172 ImmedOffset |= 1 << NumBits; 1173 ImmOp.ChangeToImmediate(ImmedOffset); 1174 Offset &= ~(Mask*Scale); 1175 } 1176 1177 // If we get here, the immediate doesn't fit into the instruction. We folded 1178 // as much as possible above, handle the rest, providing a register that is 1179 // SP+LargeImm. 1180 assert(Offset && "This code isn't needed if offset already handled!"); 1181 1182 // Insert a set of r12 with the full address: r12 = sp + offset 1183 // If the offset we have is too large to fit into the instruction, we need 1184 // to form it with a series of ADDri's. Do this by taking 8-bit chunks 1185 // out of 'Offset'. 1186 unsigned ScratchReg = findScratchRegister(RS, &ARM::GPRRegClass, AFI); 1187 if (ScratchReg == 0) 1188 // No register is "free". Scavenge a register. 1189 ScratchReg = RS->scavengeRegister(&ARM::GPRRegClass, II, SPAdj); 1190 int PIdx = MI.findFirstPredOperandIdx(); 1191 ARMCC::CondCodes Pred = (PIdx == -1) 1192 ? ARMCC::AL : (ARMCC::CondCodes)MI.getOperand(PIdx).getImm(); 1193 unsigned PredReg = (PIdx == -1) ? 0 : MI.getOperand(PIdx+1).getReg(); 1194 emitARMRegPlusImmediate(MBB, II, ScratchReg, FrameReg, 1195 isSub ? -Offset : Offset, Pred, PredReg, TII, dl); 1196 MI.getOperand(i).ChangeToRegister(ScratchReg, false, false, true); 1197} 1198 1199/// Move iterator pass the next bunch of callee save load / store ops for 1200/// the particular spill area (1: integer area 1, 2: integer area 2, 1201/// 3: fp area, 0: don't care). 1202static void movePastCSLoadStoreOps(MachineBasicBlock &MBB, 1203 MachineBasicBlock::iterator &MBBI, 1204 int Opc, unsigned Area, 1205 const ARMSubtarget &STI) { 1206 while (MBBI != MBB.end() && 1207 MBBI->getOpcode() == Opc && MBBI->getOperand(1).isFI()) { 1208 if (Area != 0) { 1209 bool Done = false; 1210 unsigned Category = 0; 1211 switch (MBBI->getOperand(0).getReg()) { 1212 case ARM::R4: case ARM::R5: case ARM::R6: case ARM::R7: 1213 case ARM::LR: 1214 Category = 1; 1215 break; 1216 case ARM::R8: case ARM::R9: case ARM::R10: case ARM::R11: 1217 Category = STI.isTargetDarwin() ? 2 : 1; 1218 break; 1219 case ARM::D8: case ARM::D9: case ARM::D10: case ARM::D11: 1220 case ARM::D12: case ARM::D13: case ARM::D14: case ARM::D15: 1221 Category = 3; 1222 break; 1223 default: 1224 Done = true; 1225 break; 1226 } 1227 if (Done || Category != Area) 1228 break; 1229 } 1230 1231 ++MBBI; 1232 } 1233} 1234 1235void ARMBaseRegisterInfo:: 1236emitPrologue(MachineFunction &MF) const { 1237 MachineBasicBlock &MBB = MF.front(); 1238 MachineBasicBlock::iterator MBBI = MBB.begin(); 1239 MachineFrameInfo *MFI = MF.getFrameInfo(); 1240 ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>(); 1241 unsigned VARegSaveSize = AFI->getVarArgsRegSaveSize(); 1242 unsigned NumBytes = MFI->getStackSize(); 1243 const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo(); 1244 DebugLoc dl = (MBBI != MBB.end() ? 1245 MBBI->getDebugLoc() : DebugLoc::getUnknownLoc()); 1246 1247 // Determine the sizes of each callee-save spill areas and record which frame 1248 // belongs to which callee-save spill areas. 1249 unsigned GPRCS1Size = 0, GPRCS2Size = 0, DPRCSSize = 0; 1250 int FramePtrSpillFI = 0; 1251 1252 if (VARegSaveSize) 1253 emitSPUpdate(MBB, MBBI, TII, dl, -VARegSaveSize); 1254 1255 if (!AFI->hasStackFrame()) { 1256 if (NumBytes != 0) 1257 emitSPUpdate(MBB, MBBI, TII, dl, -NumBytes); 1258 return; 1259 } 1260 1261 for (unsigned i = 0, e = CSI.size(); i != e; ++i) { 1262 unsigned Reg = CSI[i].getReg(); 1263 int FI = CSI[i].getFrameIdx(); 1264 switch (Reg) { 1265 case ARM::R4: 1266 case ARM::R5: 1267 case ARM::R6: 1268 case ARM::R7: 1269 case ARM::LR: 1270 if (Reg == FramePtr) 1271 FramePtrSpillFI = FI; 1272 AFI->addGPRCalleeSavedArea1Frame(FI); 1273 GPRCS1Size += 4; 1274 break; 1275 case ARM::R8: 1276 case ARM::R9: 1277 case ARM::R10: 1278 case ARM::R11: 1279 if (Reg == FramePtr) 1280 FramePtrSpillFI = FI; 1281 if (STI.isTargetDarwin()) { 1282 AFI->addGPRCalleeSavedArea2Frame(FI); 1283 GPRCS2Size += 4; 1284 } else { 1285 AFI->addGPRCalleeSavedArea1Frame(FI); 1286 GPRCS1Size += 4; 1287 } 1288 break; 1289 default: 1290 AFI->addDPRCalleeSavedAreaFrame(FI); 1291 DPRCSSize += 8; 1292 } 1293 } 1294 1295 // Build the new SUBri to adjust SP for integer callee-save spill area 1. 1296 emitSPUpdate(MBB, MBBI, TII, dl, -GPRCS1Size); 1297 movePastCSLoadStoreOps(MBB, MBBI, getOpcode(ARMII::STR), 1, STI); 1298 1299 // Darwin ABI requires FP to point to the stack slot that contains the 1300 // previous FP. 1301 if (STI.isTargetDarwin() || hasFP(MF)) { 1302 MachineInstrBuilder MIB = 1303 BuildMI(MBB, MBBI, dl, TII.get(getOpcode(ARMII::ADDri)), FramePtr) 1304 .addFrameIndex(FramePtrSpillFI).addImm(0); 1305 AddDefaultCC(AddDefaultPred(MIB)); 1306 } 1307 1308 // Build the new SUBri to adjust SP for integer callee-save spill area 2. 1309 emitSPUpdate(MBB, MBBI, TII, dl, -GPRCS2Size); 1310 1311 // Build the new SUBri to adjust SP for FP callee-save spill area. 1312 movePastCSLoadStoreOps(MBB, MBBI, getOpcode(ARMII::STR), 2, STI); 1313 emitSPUpdate(MBB, MBBI, TII, dl, -DPRCSSize); 1314 1315 // Determine starting offsets of spill areas. 1316 unsigned DPRCSOffset = NumBytes - (GPRCS1Size + GPRCS2Size + DPRCSSize); 1317 unsigned GPRCS2Offset = DPRCSOffset + DPRCSSize; 1318 unsigned GPRCS1Offset = GPRCS2Offset + GPRCS2Size; 1319 AFI->setFramePtrSpillOffset(MFI->getObjectOffset(FramePtrSpillFI) + NumBytes); 1320 AFI->setGPRCalleeSavedArea1Offset(GPRCS1Offset); 1321 AFI->setGPRCalleeSavedArea2Offset(GPRCS2Offset); 1322 AFI->setDPRCalleeSavedAreaOffset(DPRCSOffset); 1323 1324 NumBytes = DPRCSOffset; 1325 if (NumBytes) { 1326 // Insert it after all the callee-save spills. 1327 movePastCSLoadStoreOps(MBB, MBBI, getOpcode(ARMII::FSTD), 3, STI); 1328 emitSPUpdate(MBB, MBBI, TII, dl, -NumBytes); 1329 } 1330 1331 if (STI.isTargetELF() && hasFP(MF)) { 1332 MFI->setOffsetAdjustment(MFI->getOffsetAdjustment() - 1333 AFI->getFramePtrSpillOffset()); 1334 } 1335 1336 AFI->setGPRCalleeSavedArea1Size(GPRCS1Size); 1337 AFI->setGPRCalleeSavedArea2Size(GPRCS2Size); 1338 AFI->setDPRCalleeSavedAreaSize(DPRCSSize); 1339} 1340 1341static bool isCalleeSavedRegister(unsigned Reg, const unsigned *CSRegs) { 1342 for (unsigned i = 0; CSRegs[i]; ++i) 1343 if (Reg == CSRegs[i]) 1344 return true; 1345 return false; 1346} 1347 1348static bool isCSRestore(MachineInstr *MI, 1349 const ARMBaseInstrInfo &TII, 1350 const unsigned *CSRegs) { 1351 return ((MI->getOpcode() == (int)TII.getOpcode(ARMII::FLDD) || 1352 MI->getOpcode() == (int)TII.getOpcode(ARMII::LDR)) && 1353 MI->getOperand(1).isFI() && 1354 isCalleeSavedRegister(MI->getOperand(0).getReg(), CSRegs)); 1355} 1356 1357void ARMBaseRegisterInfo:: 1358emitEpilogue(MachineFunction &MF, 1359 MachineBasicBlock &MBB) const { 1360 MachineBasicBlock::iterator MBBI = prior(MBB.end()); 1361 assert(MBBI->getOpcode() == (int)getOpcode(ARMII::BX_RET) && 1362 "Can only insert epilog into returning blocks"); 1363 DebugLoc dl = MBBI->getDebugLoc(); 1364 MachineFrameInfo *MFI = MF.getFrameInfo(); 1365 ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>(); 1366 unsigned VARegSaveSize = AFI->getVarArgsRegSaveSize(); 1367 int NumBytes = (int)MFI->getStackSize(); 1368 1369 if (!AFI->hasStackFrame()) { 1370 if (NumBytes != 0) 1371 emitSPUpdate(MBB, MBBI, TII, dl, NumBytes); 1372 } else { 1373 // Unwind MBBI to point to first LDR / FLDD. 1374 const unsigned *CSRegs = getCalleeSavedRegs(); 1375 if (MBBI != MBB.begin()) { 1376 do 1377 --MBBI; 1378 while (MBBI != MBB.begin() && isCSRestore(MBBI, TII, CSRegs)); 1379 if (!isCSRestore(MBBI, TII, CSRegs)) 1380 ++MBBI; 1381 } 1382 1383 // Move SP to start of FP callee save spill area. 1384 NumBytes -= (AFI->getGPRCalleeSavedArea1Size() + 1385 AFI->getGPRCalleeSavedArea2Size() + 1386 AFI->getDPRCalleeSavedAreaSize()); 1387 1388 // Darwin ABI requires FP to point to the stack slot that contains the 1389 // previous FP. 1390 if ((STI.isTargetDarwin() && NumBytes) || hasFP(MF)) { 1391 NumBytes = AFI->getFramePtrSpillOffset() - NumBytes; 1392 // Reset SP based on frame pointer only if the stack frame extends beyond 1393 // frame pointer stack slot or target is ELF and the function has FP. 1394 if (AFI->getGPRCalleeSavedArea2Size() || 1395 AFI->getDPRCalleeSavedAreaSize() || 1396 AFI->getDPRCalleeSavedAreaOffset()|| 1397 hasFP(MF)) { 1398 if (NumBytes) 1399 BuildMI(MBB, MBBI, dl, TII.get(getOpcode(ARMII::SUBri)), ARM::SP).addReg(FramePtr) 1400 .addImm(NumBytes) 1401 .addImm((unsigned)ARMCC::AL).addReg(0).addReg(0); 1402 else 1403 BuildMI(MBB, MBBI, dl, TII.get(getOpcode(ARMII::MOVr)), ARM::SP).addReg(FramePtr) 1404 .addImm((unsigned)ARMCC::AL).addReg(0).addReg(0); 1405 } 1406 } else if (NumBytes) { 1407 emitSPUpdate(MBB, MBBI, TII, dl, NumBytes); 1408 } 1409 1410 // Move SP to start of integer callee save spill area 2. 1411 movePastCSLoadStoreOps(MBB, MBBI, getOpcode(ARMII::FLDD), 3, STI); 1412 emitSPUpdate(MBB, MBBI, TII, dl, AFI->getDPRCalleeSavedAreaSize()); 1413 1414 // Move SP to start of integer callee save spill area 1. 1415 movePastCSLoadStoreOps(MBB, MBBI, getOpcode(ARMII::LDR), 2, STI); 1416 emitSPUpdate(MBB, MBBI, TII, dl, AFI->getGPRCalleeSavedArea2Size()); 1417 1418 // Move SP to SP upon entry to the function. 1419 movePastCSLoadStoreOps(MBB, MBBI, getOpcode(ARMII::LDR), 1, STI); 1420 emitSPUpdate(MBB, MBBI, TII, dl, AFI->getGPRCalleeSavedArea1Size()); 1421 } 1422 1423 if (VARegSaveSize) 1424 emitSPUpdate(MBB, MBBI, TII, dl, VARegSaveSize); 1425 1426} 1427 1428#include "ARMGenRegisterInfo.inc" 1429