SparcAsmPrinter.cpp revision 8a0ae9e9ca918808d29379b92e245944eff70dd7
1//===-- SparcV8AsmPrinter.cpp - SparcV8 LLVM assembly writer --------------===// 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 a printer that converts from our internal representation 11// of machine-dependent LLVM code to GAS-format Sparc V8 assembly language. 12// 13//===----------------------------------------------------------------------===// 14 15#include "SparcV8.h" 16#include "SparcV8InstrInfo.h" 17#include "llvm/Constants.h" 18#include "llvm/DerivedTypes.h" 19#include "llvm/Module.h" 20#include "llvm/Assembly/Writer.h" 21#include "llvm/CodeGen/MachineFunctionPass.h" 22#include "llvm/CodeGen/MachineConstantPool.h" 23#include "llvm/CodeGen/MachineInstr.h" 24#include "llvm/Target/TargetMachine.h" 25#include "llvm/Support/Mangler.h" 26#include "Support/Statistic.h" 27#include "Support/StringExtras.h" 28#include "Support/CommandLine.h" 29#include <cctype> 30using namespace llvm; 31 32namespace { 33 Statistic<> EmittedInsts("asm-printer", "Number of machine instrs printed"); 34 35 struct V8Printer : public MachineFunctionPass { 36 /// Output stream on which we're printing assembly code. 37 /// 38 std::ostream &O; 39 40 /// Target machine description which we query for reg. names, data 41 /// layout, etc. 42 /// 43 TargetMachine &TM; 44 45 /// Name-mangler for global names. 46 /// 47 Mangler *Mang; 48 49 V8Printer(std::ostream &o, TargetMachine &tm) : O(o), TM(tm) { } 50 51 /// We name each basic block in a Function with a unique number, so 52 /// that we can consistently refer to them later. This is cleared 53 /// at the beginning of each call to runOnMachineFunction(). 54 /// 55 typedef std::map<const Value *, unsigned> ValueMapTy; 56 ValueMapTy NumberForBB; 57 58 /// Cache of mangled name for current function. This is 59 /// recalculated at the beginning of each call to 60 /// runOnMachineFunction(). 61 /// 62 std::string CurrentFnName; 63 64 virtual const char *getPassName() const { 65 return "SparcV8 Assembly Printer"; 66 } 67 68 void emitConstantValueOnly(const Constant *CV); 69 void emitGlobalConstant(const Constant *CV); 70 void printConstantPool(MachineConstantPool *MCP); 71 void printOperand(const MachineInstr *MI, int opNum); 72 void printBaseOffsetPair (const MachineInstr *MI, int i, bool brackets=true); 73 void printMachineInstruction(const MachineInstr *MI); 74 bool runOnMachineFunction(MachineFunction &F); 75 bool doInitialization(Module &M); 76 bool doFinalization(Module &M); 77 }; 78} // end of anonymous namespace 79 80/// createSparcV8CodePrinterPass - Returns a pass that prints the SparcV8 81/// assembly code for a MachineFunction to the given output stream, 82/// using the given target machine description. This should work 83/// regardless of whether the function is in SSA form. 84/// 85FunctionPass *llvm::createSparcV8CodePrinterPass (std::ostream &o, 86 TargetMachine &tm) { 87 return new V8Printer(o, tm); 88} 89 90/// toOctal - Convert the low order bits of X into an octal digit. 91/// 92static inline char toOctal(int X) { 93 return (X&7)+'0'; 94} 95 96/// getAsCString - Return the specified array as a C compatible 97/// string, only if the predicate isStringCompatible is true. 98/// 99static void printAsCString(std::ostream &O, const ConstantArray *CVA) { 100 assert(CVA->isString() && "Array is not string compatible!"); 101 102 O << "\""; 103 for (unsigned i = 0; i != CVA->getNumOperands(); ++i) { 104 unsigned char C = cast<ConstantInt>(CVA->getOperand(i))->getRawValue(); 105 106 if (C == '"') { 107 O << "\\\""; 108 } else if (C == '\\') { 109 O << "\\\\"; 110 } else if (isprint(C)) { 111 O << C; 112 } else { 113 switch(C) { 114 case '\b': O << "\\b"; break; 115 case '\f': O << "\\f"; break; 116 case '\n': O << "\\n"; break; 117 case '\r': O << "\\r"; break; 118 case '\t': O << "\\t"; break; 119 default: 120 O << '\\'; 121 O << toOctal(C >> 6); 122 O << toOctal(C >> 3); 123 O << toOctal(C >> 0); 124 break; 125 } 126 } 127 } 128 O << "\""; 129} 130 131// Print out the specified constant, without a storage class. Only the 132// constants valid in constant expressions can occur here. 133void V8Printer::emitConstantValueOnly(const Constant *CV) { 134 if (CV->isNullValue()) 135 O << "0"; 136 else if (const ConstantBool *CB = dyn_cast<ConstantBool>(CV)) { 137 assert(CB == ConstantBool::True); 138 O << "1"; 139 } else if (const ConstantSInt *CI = dyn_cast<ConstantSInt>(CV)) 140 if (((CI->getValue() << 32) >> 32) == CI->getValue()) 141 O << CI->getValue(); 142 else 143 O << (unsigned long long)CI->getValue(); 144 else if (const ConstantUInt *CI = dyn_cast<ConstantUInt>(CV)) 145 O << CI->getValue(); 146 else if (const ConstantPointerRef *CPR = dyn_cast<ConstantPointerRef>(CV)) 147 // This is a constant address for a global variable or function. Use the 148 // name of the variable or function as the address value. 149 O << Mang->getValueName(CPR->getValue()); 150 else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV)) { 151 const TargetData &TD = TM.getTargetData(); 152 switch(CE->getOpcode()) { 153 case Instruction::GetElementPtr: { 154 // generate a symbolic expression for the byte address 155 const Constant *ptrVal = CE->getOperand(0); 156 std::vector<Value*> idxVec(CE->op_begin()+1, CE->op_end()); 157 if (unsigned Offset = TD.getIndexedOffset(ptrVal->getType(), idxVec)) { 158 O << "("; 159 emitConstantValueOnly(ptrVal); 160 O << ") + " << Offset; 161 } else { 162 emitConstantValueOnly(ptrVal); 163 } 164 break; 165 } 166 case Instruction::Cast: { 167 // Support only non-converting or widening casts for now, that is, ones 168 // that do not involve a change in value. This assertion is really gross, 169 // and may not even be a complete check. 170 Constant *Op = CE->getOperand(0); 171 const Type *OpTy = Op->getType(), *Ty = CE->getType(); 172 173 // Pointers on ILP32 machines can be losslessly converted back and 174 // forth into 32-bit or wider integers, regardless of signedness. 175 assert(((isa<PointerType>(OpTy) 176 && (Ty == Type::LongTy || Ty == Type::ULongTy 177 || Ty == Type::IntTy || Ty == Type::UIntTy)) 178 || (isa<PointerType>(Ty) 179 && (OpTy == Type::LongTy || OpTy == Type::ULongTy 180 || OpTy == Type::IntTy || OpTy == Type::UIntTy)) 181 || (((TD.getTypeSize(Ty) >= TD.getTypeSize(OpTy)) 182 && OpTy->isLosslesslyConvertibleTo(Ty)))) 183 && "FIXME: Don't yet support this kind of constant cast expr"); 184 O << "("; 185 emitConstantValueOnly(Op); 186 O << ")"; 187 break; 188 } 189 case Instruction::Add: 190 O << "("; 191 emitConstantValueOnly(CE->getOperand(0)); 192 O << ") + ("; 193 emitConstantValueOnly(CE->getOperand(1)); 194 O << ")"; 195 break; 196 default: 197 assert(0 && "Unsupported operator!"); 198 } 199 } else { 200 assert(0 && "Unknown constant value!"); 201 } 202} 203 204// Print a constant value or values, with the appropriate storage class as a 205// prefix. 206void V8Printer::emitGlobalConstant(const Constant *CV) { 207 const TargetData &TD = TM.getTargetData(); 208 209 if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV)) { 210 if (CVA->isString()) { 211 O << "\t.ascii\t"; 212 printAsCString(O, CVA); 213 O << "\n"; 214 } else { // Not a string. Print the values in successive locations 215 const std::vector<Use> &constValues = CVA->getValues(); 216 for (unsigned i=0; i < constValues.size(); i++) 217 emitGlobalConstant(cast<Constant>(constValues[i].get())); 218 } 219 return; 220 } else if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV)) { 221 // Print the fields in successive locations. Pad to align if needed! 222 const StructLayout *cvsLayout = TD.getStructLayout(CVS->getType()); 223 const std::vector<Use>& constValues = CVS->getValues(); 224 unsigned sizeSoFar = 0; 225 for (unsigned i=0, N = constValues.size(); i < N; i++) { 226 const Constant* field = cast<Constant>(constValues[i].get()); 227 228 // Check if padding is needed and insert one or more 0s. 229 unsigned fieldSize = TD.getTypeSize(field->getType()); 230 unsigned padSize = ((i == N-1? cvsLayout->StructSize 231 : cvsLayout->MemberOffsets[i+1]) 232 - cvsLayout->MemberOffsets[i]) - fieldSize; 233 sizeSoFar += fieldSize + padSize; 234 235 // Now print the actual field value 236 emitGlobalConstant(field); 237 238 // Insert the field padding unless it's zero bytes... 239 if (padSize) 240 O << "\t.skip\t " << padSize << "\n"; 241 } 242 assert(sizeSoFar == cvsLayout->StructSize && 243 "Layout of constant struct may be incorrect!"); 244 return; 245 } else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV)) { 246 // FP Constants are printed as integer constants to avoid losing 247 // precision... 248 double Val = CFP->getValue(); 249 switch (CFP->getType()->getTypeID()) { 250 default: assert(0 && "Unknown floating point type!"); 251 case Type::FloatTyID: { 252 union FU { // Abide by C TBAA rules 253 float FVal; 254 unsigned UVal; 255 } U; 256 U.FVal = Val; 257 O << ".long\t" << U.UVal << "\t! float " << Val << "\n"; 258 return; 259 } 260 case Type::DoubleTyID: { 261 union DU { // Abide by C TBAA rules 262 double FVal; 263 uint64_t UVal; 264 } U; 265 U.FVal = Val; 266 O << ".quad\t" << U.UVal << "\t! double " << Val << "\n"; 267 return; 268 } 269 } 270 } 271 272 const Type *type = CV->getType(); 273 O << "\t"; 274 switch (type->getTypeID()) { 275 case Type::BoolTyID: case Type::UByteTyID: case Type::SByteTyID: 276 O << ".byte"; 277 break; 278 case Type::UShortTyID: case Type::ShortTyID: 279 O << ".word"; 280 break; 281 case Type::FloatTyID: case Type::PointerTyID: 282 case Type::UIntTyID: case Type::IntTyID: 283 O << ".long"; 284 break; 285 case Type::DoubleTyID: 286 case Type::ULongTyID: case Type::LongTyID: 287 O << ".quad"; 288 break; 289 default: 290 assert (0 && "Can't handle printing this type of thing"); 291 break; 292 } 293 O << "\t"; 294 emitConstantValueOnly(CV); 295 O << "\n"; 296} 297 298/// printConstantPool - Print to the current output stream assembly 299/// representations of the constants in the constant pool MCP. This is 300/// used to print out constants which have been "spilled to memory" by 301/// the code generator. 302/// 303void V8Printer::printConstantPool(MachineConstantPool *MCP) { 304 const std::vector<Constant*> &CP = MCP->getConstants(); 305 const TargetData &TD = TM.getTargetData(); 306 307 if (CP.empty()) return; 308 309 for (unsigned i = 0, e = CP.size(); i != e; ++i) { 310 O << "\t.section .rodata\n"; 311 O << "\t.align " << (unsigned)TD.getTypeAlignment(CP[i]->getType()) 312 << "\n"; 313 O << ".CPI" << CurrentFnName << "_" << i << ":\t\t\t\t\t!" 314 << *CP[i] << "\n"; 315 emitGlobalConstant(CP[i]); 316 } 317} 318 319/// runOnMachineFunction - This uses the printMachineInstruction() 320/// method to print assembly for each instruction. 321/// 322bool V8Printer::runOnMachineFunction(MachineFunction &MF) { 323 // BBNumber is used here so that a given Printer will never give two 324 // BBs the same name. (If you have a better way, please let me know!) 325 static unsigned BBNumber = 0; 326 327 O << "\n\n"; 328 // What's my mangled name? 329 CurrentFnName = Mang->getValueName(MF.getFunction()); 330 331 // Print out constants referenced by the function 332 printConstantPool(MF.getConstantPool()); 333 334 // Print out labels for the function. 335 O << "\t.text\n"; 336 O << "\t.align 16\n"; 337 O << "\t.globl\t" << CurrentFnName << "\n"; 338 O << "\t.type\t" << CurrentFnName << ", #function\n"; 339 O << CurrentFnName << ":\n"; 340 341 // Number each basic block so that we can consistently refer to them 342 // in PC-relative references. 343 NumberForBB.clear(); 344 for (MachineFunction::const_iterator I = MF.begin(), E = MF.end(); 345 I != E; ++I) { 346 NumberForBB[I->getBasicBlock()] = BBNumber++; 347 } 348 349 // Print out code for the function. 350 for (MachineFunction::const_iterator I = MF.begin(), E = MF.end(); 351 I != E; ++I) { 352 // Print a label for the basic block. 353 O << ".LBB" << Mang->getValueName(MF.getFunction ()) 354 << "_" << I->getNumber () << ":\t! " 355 << I->getBasicBlock ()->getName () << "\n"; 356 for (MachineBasicBlock::const_iterator II = I->begin(), E = I->end(); 357 II != E; ++II) { 358 // Print the assembly for the instruction. 359 O << "\t"; 360 printMachineInstruction(II); 361 } 362 } 363 364 // We didn't modify anything. 365 return false; 366} 367 368void V8Printer::printOperand(const MachineInstr *MI, int opNum) { 369 const MachineOperand &MO = MI->getOperand (opNum); 370 const MRegisterInfo &RI = *TM.getRegisterInfo(); 371 bool CloseParen = false; 372 if (MI->getOpcode() == V8::SETHIi && !MO.isRegister() && !MO.isImmediate()) { 373 O << "%hi("; 374 CloseParen = true; 375 } else if (MI->getOpcode() ==V8::ORri &&!MO.isRegister() &&!MO.isImmediate()) 376 { 377 O << "%lo("; 378 CloseParen = true; 379 } 380 switch (MO.getType()) { 381 case MachineOperand::MO_VirtualRegister: 382 if (Value *V = MO.getVRegValueOrNull()) { 383 O << "<" << V->getName() << ">"; 384 break; 385 } 386 // FALLTHROUGH 387 case MachineOperand::MO_MachineRegister: 388 if (MRegisterInfo::isPhysicalRegister(MO.getReg())) 389 O << "%" << LowercaseString (RI.get(MO.getReg()).Name); 390 else 391 O << "%reg" << MO.getReg(); 392 break; 393 394 case MachineOperand::MO_SignExtendedImmed: 395 case MachineOperand::MO_UnextendedImmed: 396 O << (int)MO.getImmedValue(); 397 break; 398 case MachineOperand::MO_MachineBasicBlock: { 399 MachineBasicBlock *MBBOp = MO.getMachineBasicBlock(); 400 O << ".LBB" << Mang->getValueName(MBBOp->getParent()->getFunction()) 401 << "_" << MBBOp->getNumber () << "\t! " 402 << MBBOp->getBasicBlock ()->getName (); 403 return; 404 } 405 case MachineOperand::MO_PCRelativeDisp: 406 std::cerr << "Shouldn't use addPCDisp() when building SparcV8 MachineInstrs"; 407 abort (); 408 return; 409 case MachineOperand::MO_GlobalAddress: 410 O << Mang->getValueName(MO.getGlobal()); 411 break; 412 case MachineOperand::MO_ExternalSymbol: 413 O << MO.getSymbolName(); 414 break; 415 case MachineOperand::MO_ConstantPoolIndex: 416 O << ".CPI" << CurrentFnName << "_" << MO.getConstantPoolIndex(); 417 break; 418 default: 419 O << "<unknown operand type>"; abort (); break; 420 } 421 if (CloseParen) O << ")"; 422} 423 424static bool isLoadInstruction (const MachineInstr *MI) { 425 switch (MI->getOpcode ()) { 426 case V8::LDSB: 427 case V8::LDSH: 428 case V8::LDUB: 429 case V8::LDUH: 430 case V8::LD: 431 case V8::LDD: 432 case V8::LDFrr: 433 case V8::LDFri: 434 case V8::LDDFrr: 435 case V8::LDDFri: 436 return true; 437 default: 438 return false; 439 } 440} 441 442static bool isStoreInstruction (const MachineInstr *MI) { 443 switch (MI->getOpcode ()) { 444 case V8::STB: 445 case V8::STH: 446 case V8::ST: 447 case V8::STD: 448 case V8::STFrr: 449 case V8::STFri: 450 case V8::STDFrr: 451 case V8::STDFri: 452 return true; 453 default: 454 return false; 455 } 456} 457 458/// printBaseOffsetPair - Print two consecutive operands of MI, starting at #i, 459/// which form a base + offset pair (which may have brackets around it, if 460/// brackets is true, or may be in the form base - constant, if offset is a 461/// negative constant). 462/// 463void V8Printer::printBaseOffsetPair (const MachineInstr *MI, int i, 464 bool brackets) { 465 if (brackets) O << "["; 466 printOperand (MI, i); 467 if (MI->getOperand (i + 1).isImmediate()) { 468 int Val = (int) MI->getOperand (i + 1).getImmedValue (); 469 if (Val != 0) { 470 O << ((Val >= 0) ? " + " : " - "); 471 O << ((Val >= 0) ? Val : -Val); 472 } 473 } else { 474 O << " + "; 475 printOperand (MI, i + 1); 476 } 477 if (brackets) O << "]"; 478} 479 480/// printMachineInstruction -- Print out a single SparcV8 LLVM instruction 481/// MI in GAS syntax to the current output stream. 482/// 483void V8Printer::printMachineInstruction(const MachineInstr *MI) { 484 unsigned Opcode = MI->getOpcode(); 485 const TargetInstrInfo &TII = *TM.getInstrInfo(); 486 const TargetInstrDescriptor &Desc = TII.get(Opcode); 487 O << Desc.Name << " "; 488 489 // Printing memory instructions is a special case. 490 // for loads: %dest = op %base, offset --> op [%base + offset], %dest 491 // for stores: op %base, offset, %src --> op %src, [%base + offset] 492 if (isLoadInstruction (MI)) { 493 printBaseOffsetPair (MI, 1); 494 O << ", "; 495 printOperand (MI, 0); 496 O << "\n"; 497 return; 498 } else if (isStoreInstruction (MI)) { 499 printOperand (MI, 2); 500 O << ", "; 501 printBaseOffsetPair (MI, 0); 502 O << "\n"; 503 return; 504 } else if (Opcode == V8::JMPLrr) { 505 printBaseOffsetPair (MI, 1, false); 506 O << ", "; 507 printOperand (MI, 0); 508 O << "\n"; 509 return; 510 } 511 512 // print non-immediate, non-register-def operands 513 // then print immediate operands 514 // then print register-def operands. 515 std::vector<int> print_order; 516 for (unsigned i = 0; i < MI->getNumOperands (); ++i) 517 if (!(MI->getOperand (i).isImmediate () 518 || (MI->getOperand (i).isRegister () 519 && MI->getOperand (i).isDef ()))) 520 print_order.push_back (i); 521 for (unsigned i = 0; i < MI->getNumOperands (); ++i) 522 if (MI->getOperand (i).isImmediate ()) 523 print_order.push_back (i); 524 for (unsigned i = 0; i < MI->getNumOperands (); ++i) 525 if (MI->getOperand (i).isRegister () && MI->getOperand (i).isDef ()) 526 print_order.push_back (i); 527 for (unsigned i = 0, e = print_order.size (); i != e; ++i) { 528 printOperand (MI, print_order[i]); 529 if (i != (print_order.size () - 1)) 530 O << ", "; 531 } 532 O << "\n"; 533} 534 535bool V8Printer::doInitialization(Module &M) { 536 Mang = new Mangler(M); 537 return false; // success 538} 539 540// SwitchSection - Switch to the specified section of the executable if we are 541// not already in it! 542// 543static void SwitchSection(std::ostream &OS, std::string &CurSection, 544 const char *NewSection) { 545 if (CurSection != NewSection) { 546 CurSection = NewSection; 547 if (!CurSection.empty()) 548 OS << "\t" << NewSection << "\n"; 549 } 550} 551 552bool V8Printer::doFinalization(Module &M) { 553 const TargetData &TD = TM.getTargetData(); 554 std::string CurSection; 555 556 // Print out module-level global variables here. 557 for (Module::const_giterator I = M.gbegin(), E = M.gend(); I != E; ++I) 558 if (I->hasInitializer()) { // External global require no code 559 O << "\n\n"; 560 std::string name = Mang->getValueName(I); 561 Constant *C = I->getInitializer(); 562 unsigned Size = TD.getTypeSize(C->getType()); 563 unsigned Align = TD.getTypeAlignment(C->getType()); 564 565 if (C->isNullValue() && 566 (I->hasLinkOnceLinkage() || I->hasInternalLinkage() || 567 I->hasWeakLinkage() /* FIXME: Verify correct */)) { 568 SwitchSection(O, CurSection, ".data"); 569 if (I->hasInternalLinkage()) 570 O << "\t.local " << name << "\n"; 571 572 O << "\t.comm " << name << "," << TD.getTypeSize(C->getType()) 573 << "," << (unsigned)TD.getTypeAlignment(C->getType()); 574 O << "\t\t! "; 575 WriteAsOperand(O, I, true, true, &M); 576 O << "\n"; 577 } else { 578 switch (I->getLinkage()) { 579 case GlobalValue::LinkOnceLinkage: 580 case GlobalValue::WeakLinkage: // FIXME: Verify correct for weak. 581 // Nonnull linkonce -> weak 582 O << "\t.weak " << name << "\n"; 583 SwitchSection(O, CurSection, ""); 584 O << "\t.section\t.llvm.linkonce.d." << name << ",\"aw\",@progbits\n"; 585 break; 586 587 case GlobalValue::AppendingLinkage: 588 // FIXME: appending linkage variables should go into a section of 589 // their name or something. For now, just emit them as external. 590 case GlobalValue::ExternalLinkage: 591 // If external or appending, declare as a global symbol 592 O << "\t.globl " << name << "\n"; 593 // FALL THROUGH 594 case GlobalValue::InternalLinkage: 595 if (C->isNullValue()) 596 SwitchSection(O, CurSection, ".bss"); 597 else 598 SwitchSection(O, CurSection, ".data"); 599 break; 600 } 601 602 O << "\t.align " << Align << "\n"; 603 O << "\t.type " << name << ",#object\n"; 604 O << "\t.size " << name << "," << Size << "\n"; 605 O << name << ":\t\t\t\t! "; 606 WriteAsOperand(O, I, true, true, &M); 607 O << " = "; 608 WriteAsOperand(O, C, false, false, &M); 609 O << "\n"; 610 emitGlobalConstant(C); 611 } 612 } 613 614 delete Mang; 615 return false; // success 616} 617