SelectionDAG.cpp revision 36019aa5c66abfa0cd55a21004dfef79ab2a3cde
1//===-- SelectionDAG.cpp - Implement the SelectionDAG data structures -----===// 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 implements the SelectionDAG class. 11// 12//===----------------------------------------------------------------------===// 13 14#include "llvm/CodeGen/SelectionDAG.h" 15#include "llvm/Constants.h" 16#include "llvm/GlobalValue.h" 17#include "llvm/Assembly/Writer.h" 18#include "llvm/CodeGen/MachineBasicBlock.h" 19#include "llvm/Target/TargetLowering.h" 20#include <iostream> 21#include <set> 22#include <cmath> 23#include <algorithm> 24using namespace llvm; 25 26static bool isCommutativeBinOp(unsigned Opcode) { 27 switch (Opcode) { 28 case ISD::ADD: 29 case ISD::MUL: 30 case ISD::AND: 31 case ISD::OR: 32 case ISD::XOR: return true; 33 default: return false; // FIXME: Need commutative info for user ops! 34 } 35} 36 37static bool isAssociativeBinOp(unsigned Opcode) { 38 switch (Opcode) { 39 case ISD::ADD: 40 case ISD::MUL: 41 case ISD::AND: 42 case ISD::OR: 43 case ISD::XOR: return true; 44 default: return false; // FIXME: Need associative info for user ops! 45 } 46} 47 48static unsigned ExactLog2(uint64_t Val) { 49 unsigned Count = 0; 50 while (Val != 1) { 51 Val >>= 1; 52 ++Count; 53 } 54 return Count; 55} 56 57// isInvertibleForFree - Return true if there is no cost to emitting the logical 58// inverse of this node. 59static bool isInvertibleForFree(SDOperand N) { 60 if (isa<ConstantSDNode>(N.Val)) return true; 61 if (isa<SetCCSDNode>(N.Val) && N.Val->hasOneUse()) 62 return true; 63 return false; 64} 65 66 67/// getSetCCSwappedOperands - Return the operation corresponding to (Y op X) 68/// when given the operation for (X op Y). 69ISD::CondCode ISD::getSetCCSwappedOperands(ISD::CondCode Operation) { 70 // To perform this operation, we just need to swap the L and G bits of the 71 // operation. 72 unsigned OldL = (Operation >> 2) & 1; 73 unsigned OldG = (Operation >> 1) & 1; 74 return ISD::CondCode((Operation & ~6) | // Keep the N, U, E bits 75 (OldL << 1) | // New G bit 76 (OldG << 2)); // New L bit. 77} 78 79/// getSetCCInverse - Return the operation corresponding to !(X op Y), where 80/// 'op' is a valid SetCC operation. 81ISD::CondCode ISD::getSetCCInverse(ISD::CondCode Op, bool isInteger) { 82 unsigned Operation = Op; 83 if (isInteger) 84 Operation ^= 7; // Flip L, G, E bits, but not U. 85 else 86 Operation ^= 15; // Flip all of the condition bits. 87 if (Operation > ISD::SETTRUE2) 88 Operation &= ~8; // Don't let N and U bits get set. 89 return ISD::CondCode(Operation); 90} 91 92 93/// isSignedOp - For an integer comparison, return 1 if the comparison is a 94/// signed operation and 2 if the result is an unsigned comparison. Return zero 95/// if the operation does not depend on the sign of the input (setne and seteq). 96static int isSignedOp(ISD::CondCode Opcode) { 97 switch (Opcode) { 98 default: assert(0 && "Illegal integer setcc operation!"); 99 case ISD::SETEQ: 100 case ISD::SETNE: return 0; 101 case ISD::SETLT: 102 case ISD::SETLE: 103 case ISD::SETGT: 104 case ISD::SETGE: return 1; 105 case ISD::SETULT: 106 case ISD::SETULE: 107 case ISD::SETUGT: 108 case ISD::SETUGE: return 2; 109 } 110} 111 112/// getSetCCOrOperation - Return the result of a logical OR between different 113/// comparisons of identical values: ((X op1 Y) | (X op2 Y)). This function 114/// returns SETCC_INVALID if it is not possible to represent the resultant 115/// comparison. 116ISD::CondCode ISD::getSetCCOrOperation(ISD::CondCode Op1, ISD::CondCode Op2, 117 bool isInteger) { 118 if (isInteger && (isSignedOp(Op1) | isSignedOp(Op2)) == 3) 119 // Cannot fold a signed integer setcc with an unsigned integer setcc. 120 return ISD::SETCC_INVALID; 121 122 unsigned Op = Op1 | Op2; // Combine all of the condition bits. 123 124 // If the N and U bits get set then the resultant comparison DOES suddenly 125 // care about orderedness, and is true when ordered. 126 if (Op > ISD::SETTRUE2) 127 Op &= ~16; // Clear the N bit. 128 return ISD::CondCode(Op); 129} 130 131/// getSetCCAndOperation - Return the result of a logical AND between different 132/// comparisons of identical values: ((X op1 Y) & (X op2 Y)). This 133/// function returns zero if it is not possible to represent the resultant 134/// comparison. 135ISD::CondCode ISD::getSetCCAndOperation(ISD::CondCode Op1, ISD::CondCode Op2, 136 bool isInteger) { 137 if (isInteger && (isSignedOp(Op1) | isSignedOp(Op2)) == 3) 138 // Cannot fold a signed setcc with an unsigned setcc. 139 return ISD::SETCC_INVALID; 140 141 // Combine all of the condition bits. 142 return ISD::CondCode(Op1 & Op2); 143} 144 145const TargetMachine &SelectionDAG::getTarget() const { 146 return TLI.getTargetMachine(); 147} 148 149 150/// RemoveDeadNodes - This method deletes all unreachable nodes in the 151/// SelectionDAG, including nodes (like loads) that have uses of their token 152/// chain but no other uses and no side effect. If a node is passed in as an 153/// argument, it is used as the seed for node deletion. 154void SelectionDAG::RemoveDeadNodes(SDNode *N) { 155 std::set<SDNode*> AllNodeSet(AllNodes.begin(), AllNodes.end()); 156 157 // Create a dummy node (which is not added to allnodes), that adds a reference 158 // to the root node, preventing it from being deleted. 159 SDNode *DummyNode = new SDNode(ISD::EntryToken, getRoot()); 160 161 DeleteNodeIfDead(N, &AllNodeSet); 162 163 Restart: 164 unsigned NumNodes = AllNodeSet.size(); 165 for (std::set<SDNode*>::iterator I = AllNodeSet.begin(), E = AllNodeSet.end(); 166 I != E; ++I) { 167 // Try to delete this node. 168 DeleteNodeIfDead(*I, &AllNodeSet); 169 170 // If we actually deleted any nodes, do not use invalid iterators in 171 // AllNodeSet. 172 if (AllNodeSet.size() != NumNodes) 173 goto Restart; 174 } 175 176 // Restore AllNodes. 177 if (AllNodes.size() != NumNodes) 178 AllNodes.assign(AllNodeSet.begin(), AllNodeSet.end()); 179 180 // If the root changed (e.g. it was a dead load, update the root). 181 setRoot(DummyNode->getOperand(0)); 182 183 // Now that we are done with the dummy node, delete it. 184 DummyNode->getOperand(0).Val->removeUser(DummyNode); 185 delete DummyNode; 186} 187 188void SelectionDAG::DeleteNodeIfDead(SDNode *N, void *NodeSet) { 189 if (!N->use_empty()) 190 return; 191 192 // Okay, we really are going to delete this node. First take this out of the 193 // appropriate CSE map. 194 switch (N->getOpcode()) { 195 case ISD::Constant: 196 Constants.erase(std::make_pair(cast<ConstantSDNode>(N)->getValue(), 197 N->getValueType(0))); 198 break; 199 case ISD::ConstantFP: { 200 union { 201 double DV; 202 uint64_t IV; 203 }; 204 DV = cast<ConstantFPSDNode>(N)->getValue(); 205 ConstantFPs.erase(std::make_pair(IV, N->getValueType(0))); 206 break; 207 } 208 case ISD::GlobalAddress: 209 GlobalValues.erase(cast<GlobalAddressSDNode>(N)->getGlobal()); 210 break; 211 case ISD::FrameIndex: 212 FrameIndices.erase(cast<FrameIndexSDNode>(N)->getIndex()); 213 break; 214 case ISD::ConstantPool: 215 ConstantPoolIndices.erase(cast<ConstantPoolSDNode>(N)->getIndex()); 216 break; 217 case ISD::BasicBlock: 218 BBNodes.erase(cast<BasicBlockSDNode>(N)->getBasicBlock()); 219 break; 220 case ISD::ExternalSymbol: 221 ExternalSymbols.erase(cast<ExternalSymbolSDNode>(N)->getSymbol()); 222 break; 223 224 case ISD::LOAD: 225 Loads.erase(std::make_pair(N->getOperand(1), 226 std::make_pair(N->getOperand(0), 227 N->getValueType(0)))); 228 break; 229 case ISD::SETCC: 230 SetCCs.erase(std::make_pair(std::make_pair(N->getOperand(0), 231 N->getOperand(1)), 232 std::make_pair( 233 cast<SetCCSDNode>(N)->getCondition(), 234 N->getValueType(0)))); 235 break; 236 case ISD::TRUNCSTORE: 237 case ISD::SIGN_EXTEND_INREG: 238 case ISD::FP_ROUND_INREG: 239 case ISD::EXTLOAD: 240 case ISD::SEXTLOAD: 241 case ISD::ZEXTLOAD: { 242 EVTStruct NN; 243 NN.Opcode = N->getOpcode(); 244 NN.VT = N->getValueType(0); 245 NN.EVT = cast<MVTSDNode>(N)->getExtraValueType(); 246 for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) 247 NN.Ops.push_back(N->getOperand(i)); 248 MVTSDNodes.erase(NN); 249 break; 250 } 251 default: 252 if (N->getNumOperands() == 1) 253 UnaryOps.erase(std::make_pair(N->getOpcode(), 254 std::make_pair(N->getOperand(0), 255 N->getValueType(0)))); 256 else if (N->getNumOperands() == 2) 257 BinaryOps.erase(std::make_pair(N->getOpcode(), 258 std::make_pair(N->getOperand(0), 259 N->getOperand(1)))); 260 break; 261 } 262 263 // Next, brutally remove the operand list. 264 while (!N->Operands.empty()) { 265 SDNode *O = N->Operands.back().Val; 266 N->Operands.pop_back(); 267 O->removeUser(N); 268 269 // Now that we removed this operand, see if there are no uses of it left. 270 DeleteNodeIfDead(O, NodeSet); 271 } 272 273 // Remove the node from the nodes set and delete it. 274 std::set<SDNode*> &AllNodeSet = *(std::set<SDNode*>*)NodeSet; 275 AllNodeSet.erase(N); 276 277 // Now that the node is gone, check to see if any of the operands of this node 278 // are dead now. 279 delete N; 280} 281 282 283SelectionDAG::~SelectionDAG() { 284 for (unsigned i = 0, e = AllNodes.size(); i != e; ++i) 285 delete AllNodes[i]; 286} 287 288SDOperand SelectionDAG::getZeroExtendInReg(SDOperand Op, MVT::ValueType VT) { 289 if (Op.getValueType() == VT) return Op; 290 int64_t Imm = ~0ULL >> 64-MVT::getSizeInBits(VT); 291 return getNode(ISD::AND, Op.getValueType(), Op, 292 getConstant(Imm, Op.getValueType())); 293} 294 295SDOperand SelectionDAG::getConstant(uint64_t Val, MVT::ValueType VT) { 296 assert(MVT::isInteger(VT) && "Cannot create FP integer constant!"); 297 // Mask out any bits that are not valid for this constant. 298 if (VT != MVT::i64) 299 Val &= ((uint64_t)1 << MVT::getSizeInBits(VT)) - 1; 300 301 SDNode *&N = Constants[std::make_pair(Val, VT)]; 302 if (N) return SDOperand(N, 0); 303 N = new ConstantSDNode(Val, VT); 304 AllNodes.push_back(N); 305 return SDOperand(N, 0); 306} 307 308SDOperand SelectionDAG::getConstantFP(double Val, MVT::ValueType VT) { 309 assert(MVT::isFloatingPoint(VT) && "Cannot create integer FP constant!"); 310 if (VT == MVT::f32) 311 Val = (float)Val; // Mask out extra precision. 312 313 // Do the map lookup using the actual bit pattern for the floating point 314 // value, so that we don't have problems with 0.0 comparing equal to -0.0, and 315 // we don't have issues with SNANs. 316 union { 317 double DV; 318 uint64_t IV; 319 }; 320 321 DV = Val; 322 323 SDNode *&N = ConstantFPs[std::make_pair(IV, VT)]; 324 if (N) return SDOperand(N, 0); 325 N = new ConstantFPSDNode(Val, VT); 326 AllNodes.push_back(N); 327 return SDOperand(N, 0); 328} 329 330 331 332SDOperand SelectionDAG::getGlobalAddress(const GlobalValue *GV, 333 MVT::ValueType VT) { 334 SDNode *&N = GlobalValues[GV]; 335 if (N) return SDOperand(N, 0); 336 N = new GlobalAddressSDNode(GV,VT); 337 AllNodes.push_back(N); 338 return SDOperand(N, 0); 339} 340 341SDOperand SelectionDAG::getFrameIndex(int FI, MVT::ValueType VT) { 342 SDNode *&N = FrameIndices[FI]; 343 if (N) return SDOperand(N, 0); 344 N = new FrameIndexSDNode(FI, VT); 345 AllNodes.push_back(N); 346 return SDOperand(N, 0); 347} 348 349SDOperand SelectionDAG::getConstantPool(unsigned CPIdx, MVT::ValueType VT) { 350 SDNode *N = ConstantPoolIndices[CPIdx]; 351 if (N) return SDOperand(N, 0); 352 N = new ConstantPoolSDNode(CPIdx, VT); 353 AllNodes.push_back(N); 354 return SDOperand(N, 0); 355} 356 357SDOperand SelectionDAG::getBasicBlock(MachineBasicBlock *MBB) { 358 SDNode *&N = BBNodes[MBB]; 359 if (N) return SDOperand(N, 0); 360 N = new BasicBlockSDNode(MBB); 361 AllNodes.push_back(N); 362 return SDOperand(N, 0); 363} 364 365SDOperand SelectionDAG::getExternalSymbol(const char *Sym, MVT::ValueType VT) { 366 SDNode *&N = ExternalSymbols[Sym]; 367 if (N) return SDOperand(N, 0); 368 N = new ExternalSymbolSDNode(Sym, VT); 369 AllNodes.push_back(N); 370 return SDOperand(N, 0); 371} 372 373SDOperand SelectionDAG::getSetCC(ISD::CondCode Cond, MVT::ValueType VT, 374 SDOperand N1, SDOperand N2) { 375 // These setcc operations always fold. 376 switch (Cond) { 377 default: break; 378 case ISD::SETFALSE: 379 case ISD::SETFALSE2: return getConstant(0, VT); 380 case ISD::SETTRUE: 381 case ISD::SETTRUE2: return getConstant(1, VT); 382 } 383 384 if (ConstantSDNode *N2C = dyn_cast<ConstantSDNode>(N2.Val)) { 385 uint64_t C2 = N2C->getValue(); 386 if (ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.Val)) { 387 uint64_t C1 = N1C->getValue(); 388 389 // Sign extend the operands if required 390 if (ISD::isSignedIntSetCC(Cond)) { 391 C1 = N1C->getSignExtended(); 392 C2 = N2C->getSignExtended(); 393 } 394 395 switch (Cond) { 396 default: assert(0 && "Unknown integer setcc!"); 397 case ISD::SETEQ: return getConstant(C1 == C2, VT); 398 case ISD::SETNE: return getConstant(C1 != C2, VT); 399 case ISD::SETULT: return getConstant(C1 < C2, VT); 400 case ISD::SETUGT: return getConstant(C1 > C2, VT); 401 case ISD::SETULE: return getConstant(C1 <= C2, VT); 402 case ISD::SETUGE: return getConstant(C1 >= C2, VT); 403 case ISD::SETLT: return getConstant((int64_t)C1 < (int64_t)C2, VT); 404 case ISD::SETGT: return getConstant((int64_t)C1 > (int64_t)C2, VT); 405 case ISD::SETLE: return getConstant((int64_t)C1 <= (int64_t)C2, VT); 406 case ISD::SETGE: return getConstant((int64_t)C1 >= (int64_t)C2, VT); 407 } 408 } else { 409 uint64_t MinVal, MaxVal; 410 unsigned OperandBitSize = MVT::getSizeInBits(N2C->getValueType(0)); 411 if (ISD::isSignedIntSetCC(Cond)) { 412 MinVal = 1ULL << (OperandBitSize-1); 413 if (OperandBitSize != 1) // Avoid X >> 64, which is undefined. 414 MaxVal = ~0ULL >> (65-OperandBitSize); 415 else 416 MaxVal = 0; 417 } else { 418 MinVal = 0; 419 MaxVal = ~0ULL >> (64-OperandBitSize); 420 } 421 422 // Canonicalize GE/LE comparisons to use GT/LT comparisons. 423 if (Cond == ISD::SETGE || Cond == ISD::SETUGE) { 424 if (C2 == MinVal) return getConstant(1, VT); // X >= MIN --> true 425 --C2; // X >= C1 --> X > (C1-1) 426 Cond = (Cond == ISD::SETGE) ? ISD::SETGT : ISD::SETUGT; 427 N2 = getConstant(C2, N2.getValueType()); 428 N2C = cast<ConstantSDNode>(N2.Val); 429 } 430 431 if (Cond == ISD::SETLE || Cond == ISD::SETULE) { 432 if (C2 == MaxVal) return getConstant(1, VT); // X <= MAX --> true 433 ++C2; // X <= C1 --> X < (C1+1) 434 Cond = (Cond == ISD::SETLE) ? ISD::SETLT : ISD::SETULT; 435 N2 = getConstant(C2, N2.getValueType()); 436 N2C = cast<ConstantSDNode>(N2.Val); 437 } 438 439 if ((Cond == ISD::SETLT || Cond == ISD::SETULT) && C2 == MinVal) 440 return getConstant(0, VT); // X < MIN --> false 441 442 // Canonicalize setgt X, Min --> setne X, Min 443 if ((Cond == ISD::SETGT || Cond == ISD::SETUGT) && C2 == MinVal) 444 return getSetCC(ISD::SETNE, VT, N1, N2); 445 446 // If we have setult X, 1, turn it into seteq X, 0 447 if ((Cond == ISD::SETLT || Cond == ISD::SETULT) && C2 == MinVal+1) 448 return getSetCC(ISD::SETEQ, VT, N1, 449 getConstant(MinVal, N1.getValueType())); 450 // If we have setugt X, Max-1, turn it into seteq X, Max 451 else if ((Cond == ISD::SETGT || Cond == ISD::SETUGT) && C2 == MaxVal-1) 452 return getSetCC(ISD::SETEQ, VT, N1, 453 getConstant(MaxVal, N1.getValueType())); 454 455 // If we have "setcc X, C1", check to see if we can shrink the immediate 456 // by changing cc. 457 458 // SETUGT X, SINTMAX -> SETLT X, 0 459 if (Cond == ISD::SETUGT && OperandBitSize != 1 && 460 C2 == (~0ULL >> (65-OperandBitSize))) 461 return getSetCC(ISD::SETLT, VT, N1, getConstant(0, N2.getValueType())); 462 463 // FIXME: Implement the rest of these. 464 465 } 466 } else if (isa<ConstantSDNode>(N1.Val)) { 467 // Ensure that the constant occurs on the RHS. 468 return getSetCC(ISD::getSetCCSwappedOperands(Cond), VT, N2, N1); 469 } 470 471 if (ConstantFPSDNode *N1C = dyn_cast<ConstantFPSDNode>(N1.Val)) 472 if (ConstantFPSDNode *N2C = dyn_cast<ConstantFPSDNode>(N2.Val)) { 473 double C1 = N1C->getValue(), C2 = N2C->getValue(); 474 475 switch (Cond) { 476 default: break; // FIXME: Implement the rest of these! 477 case ISD::SETEQ: return getConstant(C1 == C2, VT); 478 case ISD::SETNE: return getConstant(C1 != C2, VT); 479 case ISD::SETLT: return getConstant(C1 < C2, VT); 480 case ISD::SETGT: return getConstant(C1 > C2, VT); 481 case ISD::SETLE: return getConstant(C1 <= C2, VT); 482 case ISD::SETGE: return getConstant(C1 >= C2, VT); 483 } 484 } else { 485 // Ensure that the constant occurs on the RHS. 486 Cond = ISD::getSetCCSwappedOperands(Cond); 487 std::swap(N1, N2); 488 } 489 490 if (N1 == N2) { 491 // We can always fold X == Y for integer setcc's. 492 if (MVT::isInteger(N1.getValueType())) 493 return getConstant(ISD::isTrueWhenEqual(Cond), VT); 494 unsigned UOF = ISD::getUnorderedFlavor(Cond); 495 if (UOF == 2) // FP operators that are undefined on NaNs. 496 return getConstant(ISD::isTrueWhenEqual(Cond), VT); 497 if (UOF == ISD::isTrueWhenEqual(Cond)) 498 return getConstant(UOF, VT); 499 // Otherwise, we can't fold it. However, we can simplify it to SETUO/SETO 500 // if it is not already. 501 Cond = UOF == 0 ? ISD::SETUO : ISD::SETO; 502 } 503 504 if ((Cond == ISD::SETEQ || Cond == ISD::SETNE) && 505 MVT::isInteger(N1.getValueType())) { 506 if (N1.getOpcode() == ISD::ADD || N1.getOpcode() == ISD::SUB || 507 N1.getOpcode() == ISD::XOR) { 508 // Simplify (X+Y) == (X+Z) --> Y == Z 509 if (N1.getOpcode() == N2.getOpcode()) { 510 if (N1.getOperand(0) == N2.getOperand(0)) 511 return getSetCC(Cond, VT, N1.getOperand(1), N2.getOperand(1)); 512 if (N1.getOperand(1) == N2.getOperand(1)) 513 return getSetCC(Cond, VT, N1.getOperand(0), N2.getOperand(0)); 514 if (isCommutativeBinOp(N1.getOpcode())) { 515 // If X op Y == Y op X, try other combinations. 516 if (N1.getOperand(0) == N2.getOperand(1)) 517 return getSetCC(Cond, VT, N1.getOperand(1), N2.getOperand(0)); 518 if (N1.getOperand(1) == N2.getOperand(0)) 519 return getSetCC(Cond, VT, N1.getOperand(1), N2.getOperand(1)); 520 } 521 } 522 523 // FIXME: move this stuff to the DAG Combiner when it exists! 524 525 // Simplify (X+Z) == X --> Z == 0 526 if (N1.getOperand(0) == N2) 527 return getSetCC(Cond, VT, N1.getOperand(1), 528 getConstant(0, N1.getValueType())); 529 if (N1.getOperand(1) == N2) { 530 if (isCommutativeBinOp(N1.getOpcode())) 531 return getSetCC(Cond, VT, N1.getOperand(0), 532 getConstant(0, N1.getValueType())); 533 else { 534 assert(N1.getOpcode() == ISD::SUB && "Unexpected operation!"); 535 // (Z-X) == X --> Z == X<<1 536 return getSetCC(Cond, VT, N1.getOperand(0), 537 getNode(ISD::SHL, N2.getValueType(), 538 N2, getConstant(1, TLI.getShiftAmountTy()))); 539 } 540 } 541 } 542 543 if (N2.getOpcode() == ISD::ADD || N2.getOpcode() == ISD::SUB || 544 N2.getOpcode() == ISD::XOR) { 545 // Simplify X == (X+Z) --> Z == 0 546 if (N2.getOperand(0) == N1) 547 return getSetCC(Cond, VT, N2.getOperand(1), 548 getConstant(0, N2.getValueType())); 549 else if (N2.getOperand(1) == N1) 550 return getSetCC(Cond, VT, N2.getOperand(0), 551 getConstant(0, N2.getValueType())); 552 } 553 } 554 555 SetCCSDNode *&N = SetCCs[std::make_pair(std::make_pair(N1, N2), 556 std::make_pair(Cond, VT))]; 557 if (N) return SDOperand(N, 0); 558 N = new SetCCSDNode(Cond, N1, N2); 559 N->setValueTypes(VT); 560 AllNodes.push_back(N); 561 return SDOperand(N, 0); 562} 563 564 565 566/// getNode - Gets or creates the specified node. 567/// 568SDOperand SelectionDAG::getNode(unsigned Opcode, MVT::ValueType VT) { 569 SDNode *N = new SDNode(Opcode, VT); 570 AllNodes.push_back(N); 571 return SDOperand(N, 0); 572} 573 574SDOperand SelectionDAG::getNode(unsigned Opcode, MVT::ValueType VT, 575 SDOperand Operand) { 576 if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Operand.Val)) { 577 uint64_t Val = C->getValue(); 578 switch (Opcode) { 579 default: break; 580 case ISD::SIGN_EXTEND: return getConstant(C->getSignExtended(), VT); 581 case ISD::ZERO_EXTEND: return getConstant(Val, VT); 582 case ISD::TRUNCATE: return getConstant(Val, VT); 583 case ISD::SINT_TO_FP: return getConstantFP(C->getSignExtended(), VT); 584 case ISD::UINT_TO_FP: return getConstantFP(C->getValue(), VT); 585 } 586 } 587 588 if (ConstantFPSDNode *C = dyn_cast<ConstantFPSDNode>(Operand.Val)) 589 switch (Opcode) { 590 case ISD::FNEG: 591 return getConstantFP(-C->getValue(), VT); 592 case ISD::FP_ROUND: 593 case ISD::FP_EXTEND: 594 return getConstantFP(C->getValue(), VT); 595 case ISD::FP_TO_SINT: 596 return getConstant((int64_t)C->getValue(), VT); 597 case ISD::FP_TO_UINT: 598 return getConstant((uint64_t)C->getValue(), VT); 599 } 600 601 unsigned OpOpcode = Operand.Val->getOpcode(); 602 switch (Opcode) { 603 case ISD::TokenFactor: 604 return Operand; // Factor of one node? No factor. 605 case ISD::SIGN_EXTEND: 606 if (Operand.getValueType() == VT) return Operand; // noop extension 607 if (OpOpcode == ISD::SIGN_EXTEND || OpOpcode == ISD::ZERO_EXTEND) 608 return getNode(OpOpcode, VT, Operand.Val->getOperand(0)); 609 break; 610 case ISD::ZERO_EXTEND: 611 if (Operand.getValueType() == VT) return Operand; // noop extension 612 if (OpOpcode == ISD::ZERO_EXTEND) // (zext (zext x)) -> (zext x) 613 return getNode(ISD::ZERO_EXTEND, VT, Operand.Val->getOperand(0)); 614 break; 615 case ISD::TRUNCATE: 616 if (Operand.getValueType() == VT) return Operand; // noop truncate 617 if (OpOpcode == ISD::TRUNCATE) 618 return getNode(ISD::TRUNCATE, VT, Operand.Val->getOperand(0)); 619 else if (OpOpcode == ISD::ZERO_EXTEND || OpOpcode == ISD::SIGN_EXTEND) { 620 // If the source is smaller than the dest, we still need an extend. 621 if (Operand.Val->getOperand(0).getValueType() < VT) 622 return getNode(OpOpcode, VT, Operand.Val->getOperand(0)); 623 else if (Operand.Val->getOperand(0).getValueType() > VT) 624 return getNode(ISD::TRUNCATE, VT, Operand.Val->getOperand(0)); 625 else 626 return Operand.Val->getOperand(0); 627 } 628 break; 629 case ISD::FNEG: 630 if (OpOpcode == ISD::SUB) // -(X-Y) -> (Y-X) 631 return getNode(ISD::SUB, VT, Operand.Val->getOperand(1), 632 Operand.Val->getOperand(0)); 633 if (OpOpcode == ISD::FNEG) // --X -> X 634 return Operand.Val->getOperand(0); 635 break; 636 case ISD::FABS: 637 if (OpOpcode == ISD::FNEG) // abs(-X) -> abs(X) 638 return getNode(ISD::FABS, VT, Operand.Val->getOperand(0)); 639 break; 640 } 641 642 SDNode *&N = UnaryOps[std::make_pair(Opcode, std::make_pair(Operand, VT))]; 643 if (N) return SDOperand(N, 0); 644 N = new SDNode(Opcode, Operand); 645 N->setValueTypes(VT); 646 AllNodes.push_back(N); 647 return SDOperand(N, 0); 648} 649 650/// MaskedValueIsZero - Return true if 'V & Mask' is known to be zero. We use 651/// this predicate to simplify operations downstream. V and Mask are known to 652/// be the same type. 653static bool MaskedValueIsZero(const SDOperand &Op, uint64_t Mask, 654 const TargetLowering &TLI) { 655 unsigned SrcBits; 656 if (Mask == 0) return true; 657 658 // If we know the result of a setcc has the top bits zero, use this info. 659 switch (Op.getOpcode()) { 660 case ISD::UNDEF: 661 return true; 662 case ISD::Constant: 663 return (cast<ConstantSDNode>(Op)->getValue() & Mask) == 0; 664 665 case ISD::SETCC: 666 return ((Mask & 1) == 0) && 667 TLI.getSetCCResultContents() == TargetLowering::ZeroOrOneSetCCResult; 668 669 case ISD::ZEXTLOAD: 670 SrcBits = MVT::getSizeInBits(cast<MVTSDNode>(Op)->getExtraValueType()); 671 return (Mask & ((1ULL << SrcBits)-1)) == 0; // Returning only the zext bits. 672 case ISD::ZERO_EXTEND: 673 SrcBits = MVT::getSizeInBits(Op.getOperand(0).getValueType()); 674 return MaskedValueIsZero(Op.getOperand(0),Mask & ((1ULL << SrcBits)-1),TLI); 675 676 case ISD::AND: 677 // (X & C1) & C2 == 0 iff C1 & C2 == 0. 678 if (ConstantSDNode *AndRHS = dyn_cast<ConstantSDNode>(Op.getOperand(0))) 679 return MaskedValueIsZero(Op.getOperand(0),AndRHS->getValue() & Mask, TLI); 680 681 // FALL THROUGH 682 case ISD::OR: 683 case ISD::XOR: 684 return MaskedValueIsZero(Op.getOperand(0), Mask, TLI) && 685 MaskedValueIsZero(Op.getOperand(1), Mask, TLI); 686 case ISD::SELECT: 687 return MaskedValueIsZero(Op.getOperand(1), Mask, TLI) && 688 MaskedValueIsZero(Op.getOperand(2), Mask, TLI); 689 690 // TODO: (shl X, C1) & C2 == 0 iff (-1 << C1) & C2 == 0 691 // TODO: (ushr X, C1) & C2 == 0 iff (-1 >> C1) & C2 == 0 692 default: break; 693 } 694 695 return false; 696} 697 698 699 700SDOperand SelectionDAG::getNode(unsigned Opcode, MVT::ValueType VT, 701 SDOperand N1, SDOperand N2) { 702#ifndef NDEBUG 703 switch (Opcode) { 704 case ISD::TokenFactor: 705 assert(VT == MVT::Other && N1.getValueType() == MVT::Other && 706 N2.getValueType() == MVT::Other && "Invalid token factor!"); 707 break; 708 case ISD::AND: 709 case ISD::OR: 710 case ISD::XOR: 711 case ISD::UDIV: 712 case ISD::UREM: 713 assert(MVT::isInteger(VT) && "This operator does not apply to FP types!"); 714 // fall through 715 case ISD::ADD: 716 case ISD::SUB: 717 case ISD::MUL: 718 case ISD::SDIV: 719 case ISD::SREM: 720 assert(N1.getValueType() == N2.getValueType() && 721 N1.getValueType() == VT && "Binary operator types must match!"); 722 break; 723 724 case ISD::SHL: 725 case ISD::SRA: 726 case ISD::SRL: 727 assert(VT == N1.getValueType() && 728 "Shift operators return type must be the same as their first arg"); 729 assert(MVT::isInteger(VT) && MVT::isInteger(N2.getValueType()) && 730 VT != MVT::i1 && "Shifts only work on integers"); 731 break; 732 default: break; 733 } 734#endif 735 736 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.Val); 737 ConstantSDNode *N2C = dyn_cast<ConstantSDNode>(N2.Val); 738 if (N1C) { 739 if (N2C) { 740 uint64_t C1 = N1C->getValue(), C2 = N2C->getValue(); 741 switch (Opcode) { 742 case ISD::ADD: return getConstant(C1 + C2, VT); 743 case ISD::SUB: return getConstant(C1 - C2, VT); 744 case ISD::MUL: return getConstant(C1 * C2, VT); 745 case ISD::UDIV: 746 if (C2) return getConstant(C1 / C2, VT); 747 break; 748 case ISD::UREM : 749 if (C2) return getConstant(C1 % C2, VT); 750 break; 751 case ISD::SDIV : 752 if (C2) return getConstant(N1C->getSignExtended() / 753 N2C->getSignExtended(), VT); 754 break; 755 case ISD::SREM : 756 if (C2) return getConstant(N1C->getSignExtended() % 757 N2C->getSignExtended(), VT); 758 break; 759 case ISD::AND : return getConstant(C1 & C2, VT); 760 case ISD::OR : return getConstant(C1 | C2, VT); 761 case ISD::XOR : return getConstant(C1 ^ C2, VT); 762 case ISD::SHL : return getConstant(C1 << (int)C2, VT); 763 case ISD::SRL : return getConstant(C1 >> (unsigned)C2, VT); 764 case ISD::SRA : return getConstant(N1C->getSignExtended() >>(int)C2, VT); 765 default: break; 766 } 767 768 } else { // Cannonicalize constant to RHS if commutative 769 if (isCommutativeBinOp(Opcode)) { 770 std::swap(N1C, N2C); 771 std::swap(N1, N2); 772 } 773 } 774 775 switch (Opcode) { 776 default: break; 777 case ISD::SHL: // shl 0, X -> 0 778 if (N1C->isNullValue()) return N1; 779 break; 780 case ISD::SRL: // srl 0, X -> 0 781 if (N1C->isNullValue()) return N1; 782 break; 783 case ISD::SRA: // sra -1, X -> -1 784 if (N1C->isAllOnesValue()) return N1; 785 break; 786 } 787 } 788 789 if (N2C) { 790 uint64_t C2 = N2C->getValue(); 791 792 switch (Opcode) { 793 case ISD::ADD: 794 if (!C2) return N1; // add X, 0 -> X 795 break; 796 case ISD::SUB: 797 if (!C2) return N1; // sub X, 0 -> X 798 break; 799 case ISD::MUL: 800 if (!C2) return N2; // mul X, 0 -> 0 801 if (N2C->isAllOnesValue()) // mul X, -1 -> 0-X 802 return getNode(ISD::SUB, VT, getConstant(0, VT), N1); 803 804 // FIXME: Move this to the DAG combiner when it exists. 805 if ((C2 & C2-1) == 0) { 806 SDOperand ShAmt = getConstant(ExactLog2(C2), TLI.getShiftAmountTy()); 807 return getNode(ISD::SHL, VT, N1, ShAmt); 808 } 809 break; 810 811 case ISD::UDIV: 812 // FIXME: Move this to the DAG combiner when it exists. 813 if ((C2 & C2-1) == 0 && C2) { 814 SDOperand ShAmt = getConstant(ExactLog2(C2), TLI.getShiftAmountTy()); 815 return getNode(ISD::SRL, VT, N1, ShAmt); 816 } 817 break; 818 819 case ISD::SHL: 820 case ISD::SRL: 821 case ISD::SRA: 822 // If the shift amount is bigger than the size of the data, then all the 823 // bits are shifted out. Simplify to undef. 824 if (C2 >= MVT::getSizeInBits(N1.getValueType())) { 825 return getNode(ISD::UNDEF, N1.getValueType()); 826 } 827 if (C2 == 0) return N1; 828 break; 829 830 case ISD::AND: 831 if (!C2) return N2; // X and 0 -> 0 832 if (N2C->isAllOnesValue()) 833 return N1; // X and -1 -> X 834 835 if (MaskedValueIsZero(N1, C2, TLI)) // X and 0 -> 0 836 return getConstant(0, VT); 837 838 if (MaskedValueIsZero(N1, ~C2, TLI)) 839 return N1; // if (X & ~C2) -> 0, the and is redundant 840 841 // FIXME: Should add a corresponding version of this for 842 // ZERO_EXTEND/SIGN_EXTEND by converting them to an ANY_EXTEND node which 843 // we don't have yet. 844 845 // and (sign_extend_inreg x:16:32), 1 -> and x, 1 846 if (N1.getOpcode() == ISD::SIGN_EXTEND_INREG) { 847 // If we are masking out the part of our input that was extended, just 848 // mask the input to the extension directly. 849 unsigned ExtendBits = 850 MVT::getSizeInBits(cast<MVTSDNode>(N1)->getExtraValueType()); 851 if ((C2 & (~0ULL << ExtendBits)) == 0) 852 return getNode(ISD::AND, VT, N1.getOperand(0), N2); 853 } 854 break; 855 case ISD::OR: 856 if (!C2)return N1; // X or 0 -> X 857 if (N2C->isAllOnesValue()) 858 return N2; // X or -1 -> -1 859 break; 860 case ISD::XOR: 861 if (!C2) return N1; // X xor 0 -> X 862 if (N2C->isAllOnesValue()) { 863 if (SetCCSDNode *SetCC = dyn_cast<SetCCSDNode>(N1.Val)){ 864 // !(X op Y) -> (X !op Y) 865 bool isInteger = MVT::isInteger(SetCC->getOperand(0).getValueType()); 866 return getSetCC(ISD::getSetCCInverse(SetCC->getCondition(),isInteger), 867 SetCC->getValueType(0), 868 SetCC->getOperand(0), SetCC->getOperand(1)); 869 } else if (N1.getOpcode() == ISD::AND || N1.getOpcode() == ISD::OR) { 870 SDNode *Op = N1.Val; 871 // !(X or Y) -> (!X and !Y) iff X or Y are freely invertible 872 // !(X and Y) -> (!X or !Y) iff X or Y are freely invertible 873 SDOperand LHS = Op->getOperand(0), RHS = Op->getOperand(1); 874 if (isInvertibleForFree(RHS) || isInvertibleForFree(LHS)) { 875 LHS = getNode(ISD::XOR, VT, LHS, N2); // RHS = ~LHS 876 RHS = getNode(ISD::XOR, VT, RHS, N2); // RHS = ~RHS 877 if (Op->getOpcode() == ISD::AND) 878 return getNode(ISD::OR, VT, LHS, RHS); 879 return getNode(ISD::AND, VT, LHS, RHS); 880 } 881 } 882 // X xor -1 -> not(x) ? 883 } 884 break; 885 } 886 887 // Reassociate ((X op C1) op C2) if possible. 888 if (N1.getOpcode() == Opcode && isAssociativeBinOp(Opcode)) 889 if (ConstantSDNode *N3C = dyn_cast<ConstantSDNode>(N1.Val->getOperand(1))) 890 return getNode(Opcode, VT, N1.Val->getOperand(0), 891 getNode(Opcode, VT, N2, N1.Val->getOperand(1))); 892 } 893 894 ConstantFPSDNode *N1CFP = dyn_cast<ConstantFPSDNode>(N1.Val); 895 ConstantFPSDNode *N2CFP = dyn_cast<ConstantFPSDNode>(N2.Val); 896 if (N1CFP) 897 if (N2CFP) { 898 double C1 = N1CFP->getValue(), C2 = N2CFP->getValue(); 899 switch (Opcode) { 900 case ISD::ADD: return getConstantFP(C1 + C2, VT); 901 case ISD::SUB: return getConstantFP(C1 - C2, VT); 902 case ISD::MUL: return getConstantFP(C1 * C2, VT); 903 case ISD::SDIV: 904 if (C2) return getConstantFP(C1 / C2, VT); 905 break; 906 case ISD::SREM : 907 if (C2) return getConstantFP(fmod(C1, C2), VT); 908 break; 909 default: break; 910 } 911 912 } else { // Cannonicalize constant to RHS if commutative 913 if (isCommutativeBinOp(Opcode)) { 914 std::swap(N1CFP, N2CFP); 915 std::swap(N1, N2); 916 } 917 } 918 919 // Finally, fold operations that do not require constants. 920 switch (Opcode) { 921 case ISD::TokenFactor: 922 if (N1.getOpcode() == ISD::EntryToken) 923 return N2; 924 if (N2.getOpcode() == ISD::EntryToken) 925 return N1; 926 break; 927 928 case ISD::AND: 929 case ISD::OR: 930 if (SetCCSDNode *LHS = dyn_cast<SetCCSDNode>(N1.Val)) 931 if (SetCCSDNode *RHS = dyn_cast<SetCCSDNode>(N2.Val)) { 932 SDOperand LL = LHS->getOperand(0), RL = RHS->getOperand(0); 933 SDOperand LR = LHS->getOperand(1), RR = RHS->getOperand(1); 934 ISD::CondCode Op2 = RHS->getCondition(); 935 936 // (X op1 Y) | (Y op2 X) -> (X op1 Y) | (X swapop2 Y) 937 if (LL == RR && LR == RL) { 938 Op2 = ISD::getSetCCSwappedOperands(Op2); 939 goto MatchedBackwards; 940 } 941 942 if (LL == RL && LR == RR) { 943 MatchedBackwards: 944 ISD::CondCode Result; 945 bool isInteger = MVT::isInteger(LL.getValueType()); 946 if (Opcode == ISD::OR) 947 Result = ISD::getSetCCOrOperation(LHS->getCondition(), Op2, 948 isInteger); 949 else 950 Result = ISD::getSetCCAndOperation(LHS->getCondition(), Op2, 951 isInteger); 952 if (Result != ISD::SETCC_INVALID) 953 return getSetCC(Result, LHS->getValueType(0), LL, LR); 954 } 955 } 956 break; 957 case ISD::XOR: 958 if (N1 == N2) return getConstant(0, VT); // xor X, Y -> 0 959 break; 960 case ISD::ADD: 961 if (N2.getOpcode() == ISD::FNEG) // (A+ (-B) -> A-B 962 return getNode(ISD::SUB, VT, N1, N2.getOperand(0)); 963 if (N1.getOpcode() == ISD::FNEG) // ((-A)+B) -> B-A 964 return getNode(ISD::SUB, VT, N2, N1.getOperand(0)); 965 if (N1.getOpcode() == ISD::SUB && isa<ConstantSDNode>(N1.getOperand(0)) && 966 cast<ConstantSDNode>(N1.getOperand(0))->getValue() == 0) 967 return getNode(ISD::SUB, VT, N2, N1.getOperand(1)); // (0-A)+B -> B-A 968 if (N2.getOpcode() == ISD::SUB && isa<ConstantSDNode>(N2.getOperand(0)) && 969 cast<ConstantSDNode>(N2.getOperand(0))->getValue() == 0) 970 return getNode(ISD::SUB, VT, N1, N2.getOperand(1)); // A+(0-B) -> A-B 971 break; 972 case ISD::SUB: 973 if (N1.getOpcode() == ISD::ADD) { 974 if (N1.Val->getOperand(0) == N2) 975 return N1.Val->getOperand(1); // (A+B)-A == B 976 if (N1.Val->getOperand(1) == N2) 977 return N1.Val->getOperand(0); // (A+B)-B == A 978 } 979 if (N2.getOpcode() == ISD::FNEG) // (A- (-B) -> A+B 980 return getNode(ISD::ADD, VT, N1, N2.getOperand(0)); 981 break; 982 // FIXME: figure out how to safely handle things like 983 // int foo(int x) { return 1 << (x & 255); } 984 // int bar() { return foo(256); } 985#if 0 986 case ISD::SHL: 987 case ISD::SRL: 988 case ISD::SRA: 989 if (N2.getOpcode() == ISD::SIGN_EXTEND_INREG && 990 cast<MVTSDNode>(N2)->getExtraValueType() != MVT::i1) 991 return getNode(Opcode, VT, N1, N2.getOperand(0)); 992 else if (N2.getOpcode() == ISD::AND) 993 if (ConstantSDNode *AndRHS = dyn_cast<ConstantSDNode>(N2.getOperand(1))) { 994 // If the and is only masking out bits that cannot effect the shift, 995 // eliminate the and. 996 unsigned NumBits = MVT::getSizeInBits(VT); 997 if ((AndRHS->getValue() & (NumBits-1)) == NumBits-1) 998 return getNode(Opcode, VT, N1, N2.getOperand(0)); 999 } 1000 break; 1001#endif 1002 } 1003 1004 SDNode *&N = BinaryOps[std::make_pair(Opcode, std::make_pair(N1, N2))]; 1005 if (N) return SDOperand(N, 0); 1006 N = new SDNode(Opcode, N1, N2); 1007 N->setValueTypes(VT); 1008 1009 AllNodes.push_back(N); 1010 return SDOperand(N, 0); 1011} 1012 1013SDOperand SelectionDAG::getLoad(MVT::ValueType VT, 1014 SDOperand Chain, SDOperand Ptr) { 1015 SDNode *&N = Loads[std::make_pair(Ptr, std::make_pair(Chain, VT))]; 1016 if (N) return SDOperand(N, 0); 1017 N = new SDNode(ISD::LOAD, Chain, Ptr); 1018 1019 // Loads have a token chain. 1020 N->setValueTypes(VT, MVT::Other); 1021 AllNodes.push_back(N); 1022 return SDOperand(N, 0); 1023} 1024 1025 1026SDOperand SelectionDAG::getNode(unsigned Opcode, MVT::ValueType VT, 1027 SDOperand N1, SDOperand N2, SDOperand N3) { 1028 // Perform various simplifications. 1029 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.Val); 1030 ConstantSDNode *N2C = dyn_cast<ConstantSDNode>(N2.Val); 1031 ConstantSDNode *N3C = dyn_cast<ConstantSDNode>(N3.Val); 1032 switch (Opcode) { 1033 case ISD::SELECT: 1034 if (N1C) 1035 if (N1C->getValue()) 1036 return N2; // select true, X, Y -> X 1037 else 1038 return N3; // select false, X, Y -> Y 1039 1040 if (N2 == N3) return N2; // select C, X, X -> X 1041 1042 if (VT == MVT::i1) { // Boolean SELECT 1043 if (N2C) { 1044 if (N2C->getValue()) // select C, 1, X -> C | X 1045 return getNode(ISD::OR, VT, N1, N3); 1046 else // select C, 0, X -> ~C & X 1047 return getNode(ISD::AND, VT, 1048 getNode(ISD::XOR, N1.getValueType(), N1, 1049 getConstant(1, N1.getValueType())), N3); 1050 } else if (N3C) { 1051 if (N3C->getValue()) // select C, X, 1 -> ~C | X 1052 return getNode(ISD::OR, VT, 1053 getNode(ISD::XOR, N1.getValueType(), N1, 1054 getConstant(1, N1.getValueType())), N2); 1055 else // select C, X, 0 -> C & X 1056 return getNode(ISD::AND, VT, N1, N2); 1057 } 1058 1059 if (N1 == N2) // X ? X : Y --> X ? 1 : Y --> X | Y 1060 return getNode(ISD::OR, VT, N1, N3); 1061 if (N1 == N3) // X ? Y : X --> X ? Y : 0 --> X & Y 1062 return getNode(ISD::AND, VT, N1, N2); 1063 } 1064 1065 // If this is a selectcc, check to see if we can simplify the result. 1066 if (SetCCSDNode *SetCC = dyn_cast<SetCCSDNode>(N1)) { 1067 if (ConstantFPSDNode *CFP = 1068 dyn_cast<ConstantFPSDNode>(SetCC->getOperand(1))) 1069 if (CFP->getValue() == 0.0) { // Allow either -0.0 or 0.0 1070 // select (setg[te] X, +/-0.0), X, fneg(X) -> fabs 1071 if ((SetCC->getCondition() == ISD::SETGE || 1072 SetCC->getCondition() == ISD::SETGT) && 1073 N2 == SetCC->getOperand(0) && N3.getOpcode() == ISD::FNEG && 1074 N3.getOperand(0) == N2) 1075 return getNode(ISD::FABS, VT, N2); 1076 1077 // select (setl[te] X, +/-0.0), fneg(X), X -> fabs 1078 if ((SetCC->getCondition() == ISD::SETLT || 1079 SetCC->getCondition() == ISD::SETLE) && 1080 N3 == SetCC->getOperand(0) && N2.getOpcode() == ISD::FNEG && 1081 N2.getOperand(0) == N3) 1082 return getNode(ISD::FABS, VT, N3); 1083 } 1084 // select (setlt X, 0), A, 0 -> and (sra X, size(X)-1, A) 1085 if (ConstantSDNode *CN = 1086 dyn_cast<ConstantSDNode>(SetCC->getOperand(1))) 1087 if (CN->getValue() == 0 && N3C && N3C->getValue() == 0) 1088 if (SetCC->getCondition() == ISD::SETLT) { 1089 MVT::ValueType XType = SetCC->getOperand(0).getValueType(); 1090 MVT::ValueType AType = N2.getValueType(); 1091 if (XType >= AType) { 1092 SDOperand Shift = getNode(ISD::SRA, XType, SetCC->getOperand(0), 1093 getConstant(MVT::getSizeInBits(XType)-1, 1094 TLI.getShiftAmountTy())); 1095 if (XType > AType) 1096 Shift = getNode(ISD::TRUNCATE, AType, Shift); 1097 return getNode(ISD::AND, AType, Shift, N2); 1098 } 1099 } 1100 } 1101 break; 1102 case ISD::BRCOND: 1103 if (N2C) 1104 if (N2C->getValue()) // Unconditional branch 1105 return getNode(ISD::BR, MVT::Other, N1, N3); 1106 else 1107 return N1; // Never-taken branch 1108 break; 1109 // FIXME: figure out how to safely handle things like 1110 // int foo(int x) { return 1 << (x & 255); } 1111 // int bar() { return foo(256); } 1112#if 0 1113 case ISD::SRA_PARTS: 1114 case ISD::SRL_PARTS: 1115 case ISD::SHL_PARTS: 1116 if (N3.getOpcode() == ISD::SIGN_EXTEND_INREG && 1117 cast<MVTSDNode>(N3)->getExtraValueType() != MVT::i1) 1118 return getNode(Opcode, VT, N1, N2, N3.getOperand(0)); 1119 else if (N3.getOpcode() == ISD::AND) 1120 if (ConstantSDNode *AndRHS = dyn_cast<ConstantSDNode>(N3.getOperand(1))) { 1121 // If the and is only masking out bits that cannot effect the shift, 1122 // eliminate the and. 1123 unsigned NumBits = MVT::getSizeInBits(VT)*2; 1124 if ((AndRHS->getValue() & (NumBits-1)) == NumBits-1) 1125 return getNode(Opcode, VT, N1, N2, N3.getOperand(0)); 1126 } 1127 break; 1128#endif 1129 } 1130 1131 SDNode *N = new SDNode(Opcode, N1, N2, N3); 1132 switch (Opcode) { 1133 default: 1134 N->setValueTypes(VT); 1135 break; 1136 case ISD::DYNAMIC_STACKALLOC: // DYNAMIC_STACKALLOC produces pointer and chain 1137 N->setValueTypes(VT, MVT::Other); 1138 break; 1139 1140 case ISD::SRA_PARTS: 1141 case ISD::SRL_PARTS: 1142 case ISD::SHL_PARTS: { 1143 std::vector<MVT::ValueType> V(N->getNumOperands()-1, VT); 1144 N->setValueTypes(V); 1145 break; 1146 } 1147 } 1148 1149 // FIXME: memoize NODES 1150 AllNodes.push_back(N); 1151 return SDOperand(N, 0); 1152} 1153 1154SDOperand SelectionDAG::getNode(unsigned Opcode, MVT::ValueType VT, 1155 std::vector<SDOperand> &Children) { 1156 switch (Children.size()) { 1157 case 0: return getNode(Opcode, VT); 1158 case 1: return getNode(Opcode, VT, Children[0]); 1159 case 2: return getNode(Opcode, VT, Children[0], Children[1]); 1160 case 3: return getNode(Opcode, VT, Children[0], Children[1], Children[2]); 1161 default: break; 1162 } 1163 1164 ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(Children[1].Val); 1165 switch (Opcode) { 1166 default: break; 1167 case ISD::BRCONDTWOWAY: 1168 if (N1C) 1169 if (N1C->getValue()) // Unconditional branch to true dest. 1170 return getNode(ISD::BR, MVT::Other, Children[0], Children[2]); 1171 else // Unconditional branch to false dest. 1172 return getNode(ISD::BR, MVT::Other, Children[0], Children[3]); 1173 break; 1174 } 1175 1176 // FIXME: MEMOIZE!! 1177 SDNode *N = new SDNode(Opcode, Children); 1178 if (Opcode != ISD::ADD_PARTS && Opcode != ISD::SUB_PARTS) { 1179 N->setValueTypes(VT); 1180 } else { 1181 std::vector<MVT::ValueType> V(N->getNumOperands()/2, VT); 1182 N->setValueTypes(V); 1183 } 1184 AllNodes.push_back(N); 1185 return SDOperand(N, 0); 1186} 1187 1188SDOperand SelectionDAG::getNode(unsigned Opcode, MVT::ValueType VT,SDOperand N1, 1189 MVT::ValueType EVT) { 1190 1191 switch (Opcode) { 1192 default: assert(0 && "Bad opcode for this accessor!"); 1193 case ISD::FP_ROUND_INREG: 1194 assert(VT == N1.getValueType() && "Not an inreg round!"); 1195 assert(MVT::isFloatingPoint(VT) && MVT::isFloatingPoint(EVT) && 1196 "Cannot FP_ROUND_INREG integer types"); 1197 if (EVT == VT) return N1; // Not actually rounding 1198 assert(EVT < VT && "Not rounding down!"); 1199 1200 if (isa<ConstantFPSDNode>(N1)) 1201 return getNode(ISD::FP_EXTEND, VT, getNode(ISD::FP_ROUND, EVT, N1)); 1202 break; 1203 case ISD::SIGN_EXTEND_INREG: 1204 assert(VT == N1.getValueType() && "Not an inreg extend!"); 1205 assert(MVT::isInteger(VT) && MVT::isInteger(EVT) && 1206 "Cannot *_EXTEND_INREG FP types"); 1207 if (EVT == VT) return N1; // Not actually extending 1208 assert(EVT < VT && "Not extending!"); 1209 1210 // Extending a constant? Just return the extended constant. 1211 if (ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.Val)) { 1212 SDOperand Tmp = getNode(ISD::TRUNCATE, EVT, N1); 1213 return getNode(ISD::SIGN_EXTEND, VT, Tmp); 1214 } 1215 1216 // If we are sign extending an extension, use the original source. 1217 if (N1.getOpcode() == ISD::SIGN_EXTEND_INREG) 1218 if (cast<MVTSDNode>(N1)->getExtraValueType() <= EVT) 1219 return N1; 1220 1221 // If we are sign extending a sextload, return just the load. 1222 if (N1.getOpcode() == ISD::SEXTLOAD && Opcode == ISD::SIGN_EXTEND_INREG) 1223 if (cast<MVTSDNode>(N1)->getExtraValueType() <= EVT) 1224 return N1; 1225 1226 // If we are extending the result of a setcc, and we already know the 1227 // contents of the top bits, eliminate the extension. 1228 if (N1.getOpcode() == ISD::SETCC && 1229 TLI.getSetCCResultContents() == 1230 TargetLowering::ZeroOrNegativeOneSetCCResult) 1231 return N1; 1232 1233 // If we are sign extending the result of an (and X, C) operation, and we 1234 // know the extended bits are zeros already, don't do the extend. 1235 if (N1.getOpcode() == ISD::AND) 1236 if (ConstantSDNode *N1C = dyn_cast<ConstantSDNode>(N1.getOperand(1))) { 1237 uint64_t Mask = N1C->getValue(); 1238 unsigned NumBits = MVT::getSizeInBits(EVT); 1239 if ((Mask & (~0ULL << (NumBits-1))) == 0) 1240 return N1; 1241 } 1242 break; 1243 } 1244 1245 EVTStruct NN; 1246 NN.Opcode = Opcode; 1247 NN.VT = VT; 1248 NN.EVT = EVT; 1249 NN.Ops.push_back(N1); 1250 1251 SDNode *&N = MVTSDNodes[NN]; 1252 if (N) return SDOperand(N, 0); 1253 N = new MVTSDNode(Opcode, VT, N1, EVT); 1254 AllNodes.push_back(N); 1255 return SDOperand(N, 0); 1256} 1257 1258SDOperand SelectionDAG::getNode(unsigned Opcode, MVT::ValueType VT,SDOperand N1, 1259 SDOperand N2, MVT::ValueType EVT) { 1260 switch (Opcode) { 1261 default: assert(0 && "Bad opcode for this accessor!"); 1262 case ISD::EXTLOAD: 1263 case ISD::SEXTLOAD: 1264 case ISD::ZEXTLOAD: 1265 // If they are asking for an extending load from/to the same thing, return a 1266 // normal load. 1267 if (VT == EVT) 1268 return getNode(ISD::LOAD, VT, N1, N2); 1269 assert(EVT < VT && "Should only be an extending load, not truncating!"); 1270 assert((Opcode == ISD::EXTLOAD || MVT::isInteger(VT)) && 1271 "Cannot sign/zero extend a FP load!"); 1272 assert(MVT::isInteger(VT) == MVT::isInteger(EVT) && 1273 "Cannot convert from FP to Int or Int -> FP!"); 1274 break; 1275 } 1276 1277 EVTStruct NN; 1278 NN.Opcode = Opcode; 1279 NN.VT = VT; 1280 NN.EVT = EVT; 1281 NN.Ops.push_back(N1); 1282 NN.Ops.push_back(N2); 1283 1284 SDNode *&N = MVTSDNodes[NN]; 1285 if (N) return SDOperand(N, 0); 1286 N = new MVTSDNode(Opcode, VT, MVT::Other, N1, N2, EVT); 1287 AllNodes.push_back(N); 1288 return SDOperand(N, 0); 1289} 1290 1291SDOperand SelectionDAG::getNode(unsigned Opcode, MVT::ValueType VT,SDOperand N1, 1292 SDOperand N2, SDOperand N3, MVT::ValueType EVT) { 1293 switch (Opcode) { 1294 default: assert(0 && "Bad opcode for this accessor!"); 1295 case ISD::TRUNCSTORE: 1296#if 0 // FIXME: If the target supports EVT natively, convert to a truncate/store 1297 // If this is a truncating store of a constant, convert to the desired type 1298 // and store it instead. 1299 if (isa<Constant>(N1)) { 1300 SDOperand Op = getNode(ISD::TRUNCATE, EVT, N1); 1301 if (isa<Constant>(Op)) 1302 N1 = Op; 1303 } 1304 // Also for ConstantFP? 1305#endif 1306 if (N1.getValueType() == EVT) // Normal store? 1307 return getNode(ISD::STORE, VT, N1, N2, N3); 1308 assert(N2.getValueType() > EVT && "Not a truncation?"); 1309 assert(MVT::isInteger(N2.getValueType()) == MVT::isInteger(EVT) && 1310 "Can't do FP-INT conversion!"); 1311 break; 1312 } 1313 1314 EVTStruct NN; 1315 NN.Opcode = Opcode; 1316 NN.VT = VT; 1317 NN.EVT = EVT; 1318 NN.Ops.push_back(N1); 1319 NN.Ops.push_back(N2); 1320 NN.Ops.push_back(N3); 1321 1322 SDNode *&N = MVTSDNodes[NN]; 1323 if (N) return SDOperand(N, 0); 1324 N = new MVTSDNode(Opcode, VT, N1, N2, N3, EVT); 1325 AllNodes.push_back(N); 1326 return SDOperand(N, 0); 1327} 1328 1329 1330/// hasNUsesOfValue - Return true if there are exactly NUSES uses of the 1331/// indicated value. This method ignores uses of other values defined by this 1332/// operation. 1333bool SDNode::hasNUsesOfValue(unsigned NUses, unsigned Value) { 1334 assert(Value < getNumValues() && "Bad value!"); 1335 1336 // If there is only one value, this is easy. 1337 if (getNumValues() == 1) 1338 return use_size() == NUses; 1339 if (Uses.size() < NUses) return false; 1340 1341 SDOperand TheValue(this, Value); 1342 1343 std::set<SDNode*> UsersHandled; 1344 1345 for (std::vector<SDNode*>::iterator UI = Uses.begin(), E = Uses.end(); 1346 UI != E; ++UI) { 1347 SDNode *User = *UI; 1348 if (User->getNumOperands() == 1 || 1349 UsersHandled.insert(User).second) // First time we've seen this? 1350 for (unsigned i = 0, e = User->getNumOperands(); i != e; ++i) 1351 if (User->getOperand(i) == TheValue) { 1352 if (NUses == 0) 1353 return false; // too many uses 1354 --NUses; 1355 } 1356 } 1357 1358 // Found exactly the right number of uses? 1359 return NUses == 0; 1360} 1361 1362 1363const char *SDNode::getOperationName() const { 1364 switch (getOpcode()) { 1365 default: return "<<Unknown>>"; 1366 case ISD::PCMARKER: return "PCMarker"; 1367 case ISD::EntryToken: return "EntryToken"; 1368 case ISD::TokenFactor: return "TokenFactor"; 1369 case ISD::Constant: return "Constant"; 1370 case ISD::ConstantFP: return "ConstantFP"; 1371 case ISD::GlobalAddress: return "GlobalAddress"; 1372 case ISD::FrameIndex: return "FrameIndex"; 1373 case ISD::BasicBlock: return "BasicBlock"; 1374 case ISD::ExternalSymbol: return "ExternalSymbol"; 1375 case ISD::ConstantPool: return "ConstantPoolIndex"; 1376 case ISD::CopyToReg: return "CopyToReg"; 1377 case ISD::CopyFromReg: return "CopyFromReg"; 1378 case ISD::ImplicitDef: return "ImplicitDef"; 1379 case ISD::UNDEF: return "undef"; 1380 1381 // Unary operators 1382 case ISD::FABS: return "fabs"; 1383 case ISD::FNEG: return "fneg"; 1384 1385 // Binary operators 1386 case ISD::ADD: return "add"; 1387 case ISD::SUB: return "sub"; 1388 case ISD::MUL: return "mul"; 1389 case ISD::MULHU: return "mulhu"; 1390 case ISD::MULHS: return "mulhs"; 1391 case ISD::SDIV: return "sdiv"; 1392 case ISD::UDIV: return "udiv"; 1393 case ISD::SREM: return "srem"; 1394 case ISD::UREM: return "urem"; 1395 case ISD::AND: return "and"; 1396 case ISD::OR: return "or"; 1397 case ISD::XOR: return "xor"; 1398 case ISD::SHL: return "shl"; 1399 case ISD::SRA: return "sra"; 1400 case ISD::SRL: return "srl"; 1401 1402 case ISD::SELECT: return "select"; 1403 case ISD::ADD_PARTS: return "add_parts"; 1404 case ISD::SUB_PARTS: return "sub_parts"; 1405 case ISD::SHL_PARTS: return "shl_parts"; 1406 case ISD::SRA_PARTS: return "sra_parts"; 1407 case ISD::SRL_PARTS: return "srl_parts"; 1408 1409 // Conversion operators. 1410 case ISD::SIGN_EXTEND: return "sign_extend"; 1411 case ISD::ZERO_EXTEND: return "zero_extend"; 1412 case ISD::SIGN_EXTEND_INREG: return "sign_extend_inreg"; 1413 case ISD::TRUNCATE: return "truncate"; 1414 case ISD::FP_ROUND: return "fp_round"; 1415 case ISD::FP_ROUND_INREG: return "fp_round_inreg"; 1416 case ISD::FP_EXTEND: return "fp_extend"; 1417 1418 case ISD::SINT_TO_FP: return "sint_to_fp"; 1419 case ISD::UINT_TO_FP: return "uint_to_fp"; 1420 case ISD::FP_TO_SINT: return "fp_to_sint"; 1421 case ISD::FP_TO_UINT: return "fp_to_uint"; 1422 1423 // Control flow instructions 1424 case ISD::BR: return "br"; 1425 case ISD::BRCOND: return "brcond"; 1426 case ISD::BRCONDTWOWAY: return "brcondtwoway"; 1427 case ISD::RET: return "ret"; 1428 case ISD::CALL: return "call"; 1429 case ISD::ADJCALLSTACKDOWN: return "adjcallstackdown"; 1430 case ISD::ADJCALLSTACKUP: return "adjcallstackup"; 1431 1432 // Other operators 1433 case ISD::LOAD: return "load"; 1434 case ISD::STORE: return "store"; 1435 case ISD::EXTLOAD: return "extload"; 1436 case ISD::SEXTLOAD: return "sextload"; 1437 case ISD::ZEXTLOAD: return "zextload"; 1438 case ISD::TRUNCSTORE: return "truncstore"; 1439 1440 case ISD::DYNAMIC_STACKALLOC: return "dynamic_stackalloc"; 1441 case ISD::EXTRACT_ELEMENT: return "extract_element"; 1442 case ISD::BUILD_PAIR: return "build_pair"; 1443 case ISD::MEMSET: return "memset"; 1444 case ISD::MEMCPY: return "memcpy"; 1445 case ISD::MEMMOVE: return "memmove"; 1446 1447 case ISD::SETCC: 1448 const SetCCSDNode *SetCC = cast<SetCCSDNode>(this); 1449 switch (SetCC->getCondition()) { 1450 default: assert(0 && "Unknown setcc condition!"); 1451 case ISD::SETOEQ: return "setcc:setoeq"; 1452 case ISD::SETOGT: return "setcc:setogt"; 1453 case ISD::SETOGE: return "setcc:setoge"; 1454 case ISD::SETOLT: return "setcc:setolt"; 1455 case ISD::SETOLE: return "setcc:setole"; 1456 case ISD::SETONE: return "setcc:setone"; 1457 1458 case ISD::SETO: return "setcc:seto"; 1459 case ISD::SETUO: return "setcc:setuo"; 1460 case ISD::SETUEQ: return "setcc:setue"; 1461 case ISD::SETUGT: return "setcc:setugt"; 1462 case ISD::SETUGE: return "setcc:setuge"; 1463 case ISD::SETULT: return "setcc:setult"; 1464 case ISD::SETULE: return "setcc:setule"; 1465 case ISD::SETUNE: return "setcc:setune"; 1466 1467 case ISD::SETEQ: return "setcc:seteq"; 1468 case ISD::SETGT: return "setcc:setgt"; 1469 case ISD::SETGE: return "setcc:setge"; 1470 case ISD::SETLT: return "setcc:setlt"; 1471 case ISD::SETLE: return "setcc:setle"; 1472 case ISD::SETNE: return "setcc:setne"; 1473 } 1474 } 1475} 1476 1477void SDNode::dump() const { 1478 std::cerr << (void*)this << ": "; 1479 1480 for (unsigned i = 0, e = getNumValues(); i != e; ++i) { 1481 if (i) std::cerr << ","; 1482 if (getValueType(i) == MVT::Other) 1483 std::cerr << "ch"; 1484 else 1485 std::cerr << MVT::getValueTypeString(getValueType(i)); 1486 } 1487 std::cerr << " = " << getOperationName(); 1488 1489 std::cerr << " "; 1490 for (unsigned i = 0, e = getNumOperands(); i != e; ++i) { 1491 if (i) std::cerr << ", "; 1492 std::cerr << (void*)getOperand(i).Val; 1493 if (unsigned RN = getOperand(i).ResNo) 1494 std::cerr << ":" << RN; 1495 } 1496 1497 if (const ConstantSDNode *CSDN = dyn_cast<ConstantSDNode>(this)) { 1498 std::cerr << "<" << CSDN->getValue() << ">"; 1499 } else if (const ConstantFPSDNode *CSDN = dyn_cast<ConstantFPSDNode>(this)) { 1500 std::cerr << "<" << CSDN->getValue() << ">"; 1501 } else if (const GlobalAddressSDNode *GADN = 1502 dyn_cast<GlobalAddressSDNode>(this)) { 1503 std::cerr << "<"; 1504 WriteAsOperand(std::cerr, GADN->getGlobal()) << ">"; 1505 } else if (const FrameIndexSDNode *FIDN = 1506 dyn_cast<FrameIndexSDNode>(this)) { 1507 std::cerr << "<" << FIDN->getIndex() << ">"; 1508 } else if (const ConstantPoolSDNode *CP = dyn_cast<ConstantPoolSDNode>(this)){ 1509 std::cerr << "<" << CP->getIndex() << ">"; 1510 } else if (const BasicBlockSDNode *BBDN = 1511 dyn_cast<BasicBlockSDNode>(this)) { 1512 std::cerr << "<"; 1513 const Value *LBB = (const Value*)BBDN->getBasicBlock()->getBasicBlock(); 1514 if (LBB) 1515 std::cerr << LBB->getName() << " "; 1516 std::cerr << (const void*)BBDN->getBasicBlock() << ">"; 1517 } else if (const RegSDNode *C2V = dyn_cast<RegSDNode>(this)) { 1518 std::cerr << "<reg #" << C2V->getReg() << ">"; 1519 } else if (const ExternalSymbolSDNode *ES = 1520 dyn_cast<ExternalSymbolSDNode>(this)) { 1521 std::cerr << "'" << ES->getSymbol() << "'"; 1522 } else if (const MVTSDNode *M = dyn_cast<MVTSDNode>(this)) { 1523 std::cerr << " - Ty = " << MVT::getValueTypeString(M->getExtraValueType()); 1524 } 1525} 1526 1527static void DumpNodes(SDNode *N, unsigned indent) { 1528 for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) 1529 if (N->getOperand(i).Val->hasOneUse()) 1530 DumpNodes(N->getOperand(i).Val, indent+2); 1531 else 1532 std::cerr << "\n" << std::string(indent+2, ' ') 1533 << (void*)N->getOperand(i).Val << ": <multiple use>"; 1534 1535 1536 std::cerr << "\n" << std::string(indent, ' '); 1537 N->dump(); 1538} 1539 1540void SelectionDAG::dump() const { 1541 std::cerr << "SelectionDAG has " << AllNodes.size() << " nodes:"; 1542 std::vector<SDNode*> Nodes(AllNodes); 1543 std::sort(Nodes.begin(), Nodes.end()); 1544 1545 for (unsigned i = 0, e = Nodes.size(); i != e; ++i) { 1546 if (!Nodes[i]->hasOneUse() && Nodes[i] != getRoot().Val) 1547 DumpNodes(Nodes[i], 2); 1548 } 1549 1550 DumpNodes(getRoot().Val, 2); 1551 1552 std::cerr << "\n\n"; 1553} 1554 1555