InstCombineCalls.cpp revision f79d6246e6b6a83e31a1360e80f828707a51f98e
1//===- InstCombineCalls.cpp -----------------------------------------------===// 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 implements the visitCall and visitInvoke functions. 11// 12//===----------------------------------------------------------------------===// 13 14#include "InstCombine.h" 15#include "llvm/IntrinsicInst.h" 16#include "llvm/Support/CallSite.h" 17#include "llvm/Target/TargetData.h" 18#include "llvm/Analysis/MemoryBuiltins.h" 19using namespace llvm; 20 21/// getPromotedType - Return the specified type promoted as it would be to pass 22/// though a va_arg area. 23static const Type *getPromotedType(const Type *Ty) { 24 if (const IntegerType* ITy = dyn_cast<IntegerType>(Ty)) { 25 if (ITy->getBitWidth() < 32) 26 return Type::getInt32Ty(Ty->getContext()); 27 } 28 return Ty; 29} 30 31/// EnforceKnownAlignment - If the specified pointer points to an object that 32/// we control, modify the object's alignment to PrefAlign. This isn't 33/// often possible though. If alignment is important, a more reliable approach 34/// is to simply align all global variables and allocation instructions to 35/// their preferred alignment from the beginning. 36/// 37static unsigned EnforceKnownAlignment(Value *V, 38 unsigned Align, unsigned PrefAlign) { 39 40 User *U = dyn_cast<User>(V); 41 if (!U) return Align; 42 43 switch (Operator::getOpcode(U)) { 44 default: break; 45 case Instruction::BitCast: 46 return EnforceKnownAlignment(U->getOperand(0), Align, PrefAlign); 47 case Instruction::GetElementPtr: { 48 // If all indexes are zero, it is just the alignment of the base pointer. 49 bool AllZeroOperands = true; 50 for (User::op_iterator i = U->op_begin() + 1, e = U->op_end(); i != e; ++i) 51 if (!isa<Constant>(*i) || 52 !cast<Constant>(*i)->isNullValue()) { 53 AllZeroOperands = false; 54 break; 55 } 56 57 if (AllZeroOperands) { 58 // Treat this like a bitcast. 59 return EnforceKnownAlignment(U->getOperand(0), Align, PrefAlign); 60 } 61 break; 62 } 63 } 64 65 if (GlobalValue *GV = dyn_cast<GlobalValue>(V)) { 66 // If there is a large requested alignment and we can, bump up the alignment 67 // of the global. 68 if (!GV->isDeclaration()) { 69 if (GV->getAlignment() >= PrefAlign) 70 Align = GV->getAlignment(); 71 else { 72 GV->setAlignment(PrefAlign); 73 Align = PrefAlign; 74 } 75 } 76 } else if (AllocaInst *AI = dyn_cast<AllocaInst>(V)) { 77 // If there is a requested alignment and if this is an alloca, round up. 78 if (AI->getAlignment() >= PrefAlign) 79 Align = AI->getAlignment(); 80 else { 81 AI->setAlignment(PrefAlign); 82 Align = PrefAlign; 83 } 84 } 85 86 return Align; 87} 88 89/// GetOrEnforceKnownAlignment - If the specified pointer has an alignment that 90/// we can determine, return it, otherwise return 0. If PrefAlign is specified, 91/// and it is more than the alignment of the ultimate object, see if we can 92/// increase the alignment of the ultimate object, making this check succeed. 93unsigned InstCombiner::GetOrEnforceKnownAlignment(Value *V, 94 unsigned PrefAlign) { 95 unsigned BitWidth = TD ? TD->getTypeSizeInBits(V->getType()) : 96 sizeof(PrefAlign) * CHAR_BIT; 97 APInt Mask = APInt::getAllOnesValue(BitWidth); 98 APInt KnownZero(BitWidth, 0), KnownOne(BitWidth, 0); 99 ComputeMaskedBits(V, Mask, KnownZero, KnownOne); 100 unsigned TrailZ = KnownZero.countTrailingOnes(); 101 unsigned Align = 1u << std::min(BitWidth - 1, TrailZ); 102 103 if (PrefAlign > Align) 104 Align = EnforceKnownAlignment(V, Align, PrefAlign); 105 106 // We don't need to make any adjustment. 107 return Align; 108} 109 110Instruction *InstCombiner::SimplifyMemTransfer(MemIntrinsic *MI) { 111 unsigned DstAlign = GetOrEnforceKnownAlignment(MI->getOperand(1)); 112 unsigned SrcAlign = GetOrEnforceKnownAlignment(MI->getOperand(2)); 113 unsigned MinAlign = std::min(DstAlign, SrcAlign); 114 unsigned CopyAlign = MI->getAlignment(); 115 116 if (CopyAlign < MinAlign) { 117 MI->setAlignment(ConstantInt::get(MI->getAlignmentType(), 118 MinAlign, false)); 119 return MI; 120 } 121 122 // If MemCpyInst length is 1/2/4/8 bytes then replace memcpy with 123 // load/store. 124 ConstantInt *MemOpLength = dyn_cast<ConstantInt>(MI->getOperand(3)); 125 if (MemOpLength == 0) return 0; 126 127 // Source and destination pointer types are always "i8*" for intrinsic. See 128 // if the size is something we can handle with a single primitive load/store. 129 // A single load+store correctly handles overlapping memory in the memmove 130 // case. 131 unsigned Size = MemOpLength->getZExtValue(); 132 if (Size == 0) return MI; // Delete this mem transfer. 133 134 if (Size > 8 || (Size&(Size-1))) 135 return 0; // If not 1/2/4/8 bytes, exit. 136 137 // Use an integer load+store unless we can find something better. 138 Type *NewPtrTy = 139 PointerType::getUnqual(IntegerType::get(MI->getContext(), Size<<3)); 140 141 // Memcpy forces the use of i8* for the source and destination. That means 142 // that if you're using memcpy to move one double around, you'll get a cast 143 // from double* to i8*. We'd much rather use a double load+store rather than 144 // an i64 load+store, here because this improves the odds that the source or 145 // dest address will be promotable. See if we can find a better type than the 146 // integer datatype. 147 Value *StrippedDest = MI->getOperand(1)->stripPointerCasts(); 148 if (StrippedDest != MI->getOperand(1)) { 149 const Type *SrcETy = cast<PointerType>(StrippedDest->getType()) 150 ->getElementType(); 151 if (TD && SrcETy->isSized() && TD->getTypeStoreSize(SrcETy) == Size) { 152 // The SrcETy might be something like {{{double}}} or [1 x double]. Rip 153 // down through these levels if so. 154 while (!SrcETy->isSingleValueType()) { 155 if (const StructType *STy = dyn_cast<StructType>(SrcETy)) { 156 if (STy->getNumElements() == 1) 157 SrcETy = STy->getElementType(0); 158 else 159 break; 160 } else if (const ArrayType *ATy = dyn_cast<ArrayType>(SrcETy)) { 161 if (ATy->getNumElements() == 1) 162 SrcETy = ATy->getElementType(); 163 else 164 break; 165 } else 166 break; 167 } 168 169 if (SrcETy->isSingleValueType()) 170 NewPtrTy = PointerType::getUnqual(SrcETy); 171 } 172 } 173 174 175 // If the memcpy/memmove provides better alignment info than we can 176 // infer, use it. 177 SrcAlign = std::max(SrcAlign, CopyAlign); 178 DstAlign = std::max(DstAlign, CopyAlign); 179 180 Value *Src = Builder->CreateBitCast(MI->getOperand(2), NewPtrTy); 181 Value *Dest = Builder->CreateBitCast(MI->getOperand(1), NewPtrTy); 182 Instruction *L = new LoadInst(Src, "tmp", false, SrcAlign); 183 InsertNewInstBefore(L, *MI); 184 InsertNewInstBefore(new StoreInst(L, Dest, false, DstAlign), *MI); 185 186 // Set the size of the copy to 0, it will be deleted on the next iteration. 187 MI->setOperand(3, Constant::getNullValue(MemOpLength->getType())); 188 return MI; 189} 190 191Instruction *InstCombiner::SimplifyMemSet(MemSetInst *MI) { 192 unsigned Alignment = GetOrEnforceKnownAlignment(MI->getDest()); 193 if (MI->getAlignment() < Alignment) { 194 MI->setAlignment(ConstantInt::get(MI->getAlignmentType(), 195 Alignment, false)); 196 return MI; 197 } 198 199 // Extract the length and alignment and fill if they are constant. 200 ConstantInt *LenC = dyn_cast<ConstantInt>(MI->getLength()); 201 ConstantInt *FillC = dyn_cast<ConstantInt>(MI->getValue()); 202 if (!LenC || !FillC || !FillC->getType()->isIntegerTy(8)) 203 return 0; 204 uint64_t Len = LenC->getZExtValue(); 205 Alignment = MI->getAlignment(); 206 207 // If the length is zero, this is a no-op 208 if (Len == 0) return MI; // memset(d,c,0,a) -> noop 209 210 // memset(s,c,n) -> store s, c (for n=1,2,4,8) 211 if (Len <= 8 && isPowerOf2_32((uint32_t)Len)) { 212 const Type *ITy = IntegerType::get(MI->getContext(), Len*8); // n=1 -> i8. 213 214 Value *Dest = MI->getDest(); 215 Dest = Builder->CreateBitCast(Dest, PointerType::getUnqual(ITy)); 216 217 // Alignment 0 is identity for alignment 1 for memset, but not store. 218 if (Alignment == 0) Alignment = 1; 219 220 // Extract the fill value and store. 221 uint64_t Fill = FillC->getZExtValue()*0x0101010101010101ULL; 222 InsertNewInstBefore(new StoreInst(ConstantInt::get(ITy, Fill), 223 Dest, false, Alignment), *MI); 224 225 // Set the size of the copy to 0, it will be deleted on the next iteration. 226 MI->setLength(Constant::getNullValue(LenC->getType())); 227 return MI; 228 } 229 230 return 0; 231} 232 233/// visitCallInst - CallInst simplification. This mostly only handles folding 234/// of intrinsic instructions. For normal calls, it allows visitCallSite to do 235/// the heavy lifting. 236/// 237Instruction *InstCombiner::visitCallInst(CallInst &CI) { 238 if (isFreeCall(&CI)) 239 return visitFree(CI); 240 241 // If the caller function is nounwind, mark the call as nounwind, even if the 242 // callee isn't. 243 if (CI.getParent()->getParent()->doesNotThrow() && 244 !CI.doesNotThrow()) { 245 CI.setDoesNotThrow(); 246 return &CI; 247 } 248 249 IntrinsicInst *II = dyn_cast<IntrinsicInst>(&CI); 250 if (!II) return visitCallSite(&CI); 251 252 // Intrinsics cannot occur in an invoke, so handle them here instead of in 253 // visitCallSite. 254 if (MemIntrinsic *MI = dyn_cast<MemIntrinsic>(II)) { 255 bool Changed = false; 256 257 // memmove/cpy/set of zero bytes is a noop. 258 if (Constant *NumBytes = dyn_cast<Constant>(MI->getLength())) { 259 if (NumBytes->isNullValue()) return EraseInstFromFunction(CI); 260 261 if (ConstantInt *CI = dyn_cast<ConstantInt>(NumBytes)) 262 if (CI->getZExtValue() == 1) { 263 // Replace the instruction with just byte operations. We would 264 // transform other cases to loads/stores, but we don't know if 265 // alignment is sufficient. 266 } 267 } 268 269 // If we have a memmove and the source operation is a constant global, 270 // then the source and dest pointers can't alias, so we can change this 271 // into a call to memcpy. 272 if (MemMoveInst *MMI = dyn_cast<MemMoveInst>(MI)) { 273 if (GlobalVariable *GVSrc = dyn_cast<GlobalVariable>(MMI->getSource())) 274 if (GVSrc->isConstant()) { 275 Module *M = CI.getParent()->getParent()->getParent(); 276 Intrinsic::ID MemCpyID = Intrinsic::memcpy; 277 const Type *Tys[1]; 278 Tys[0] = CI.getOperand(3)->getType(); 279 CI.setOperand(0, 280 Intrinsic::getDeclaration(M, MemCpyID, Tys, 1)); 281 Changed = true; 282 } 283 } 284 285 if (MemTransferInst *MTI = dyn_cast<MemTransferInst>(MI)) { 286 // memmove(x,x,size) -> noop. 287 if (MTI->getSource() == MTI->getDest()) 288 return EraseInstFromFunction(CI); 289 } 290 291 // If we can determine a pointer alignment that is bigger than currently 292 // set, update the alignment. 293 if (isa<MemTransferInst>(MI)) { 294 if (Instruction *I = SimplifyMemTransfer(MI)) 295 return I; 296 } else if (MemSetInst *MSI = dyn_cast<MemSetInst>(MI)) { 297 if (Instruction *I = SimplifyMemSet(MSI)) 298 return I; 299 } 300 301 if (Changed) return II; 302 } 303 304 switch (II->getIntrinsicID()) { 305 default: break; 306 case Intrinsic::objectsize: { 307 const Type *ReturnTy = CI.getType(); 308 Value *Op1 = II->getOperand(1); 309 bool Min = (cast<ConstantInt>(II->getOperand(2))->getZExtValue() == 1); 310 311 // We need target data for just about everything so depend on it. 312 if (!TD) break; 313 314 // Get to the real allocated thing and offset as fast as possible. 315 Op1 = Op1->stripPointerCasts(); 316 317 // If we've stripped down to a single global variable that we 318 // can know the size of then just return that. 319 if (GlobalVariable *GV = dyn_cast<GlobalVariable>(Op1)) { 320 if (GV->hasDefinitiveInitializer()) { 321 Constant *C = GV->getInitializer(); 322 uint64_t globalSize = TD->getTypeAllocSize(C->getType()); 323 return ReplaceInstUsesWith(CI, ConstantInt::get(ReturnTy, globalSize)); 324 } else { 325 Constant *RetVal = ConstantInt::get(ReturnTy, Min ? 0 : -1ULL); 326 return ReplaceInstUsesWith(CI, RetVal); 327 } 328 } else if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Op1)) { 329 330 // Only handle constant GEPs here. 331 if (CE->getOpcode() != Instruction::GetElementPtr) break; 332 GEPOperator *GEP = cast<GEPOperator>(CE); 333 334 // Make sure we're not a constant offset from an external 335 // global. 336 Value *Operand = GEP->getPointerOperand(); 337 Operand = Operand->stripPointerCasts(); 338 if (GlobalVariable *GV = dyn_cast<GlobalVariable>(Operand)) 339 if (!GV->hasDefinitiveInitializer()) break; 340 341 // Get what we're pointing to and its size. 342 const PointerType *BaseType = 343 cast<PointerType>(Operand->getType()); 344 uint64_t Size = TD->getTypeAllocSize(BaseType->getElementType()); 345 346 // Get the current byte offset into the thing. Use the original 347 // operand in case we're looking through a bitcast. 348 SmallVector<Value*, 8> Ops(CE->op_begin()+1, CE->op_end()); 349 const PointerType *OffsetType = 350 cast<PointerType>(GEP->getPointerOperand()->getType()); 351 uint64_t Offset = TD->getIndexedOffset(OffsetType, &Ops[0], Ops.size()); 352 353 if (Size < Offset) { 354 // Out of bound reference? Negative index normalized to large 355 // index? Just return "I don't know". 356 Constant *RetVal = ConstantInt::get(ReturnTy, Min ? 0 : -1ULL); 357 return ReplaceInstUsesWith(CI, RetVal); 358 } 359 360 Constant *RetVal = ConstantInt::get(ReturnTy, Size-Offset); 361 return ReplaceInstUsesWith(CI, RetVal); 362 363 } 364 break; 365 } 366 case Intrinsic::bswap: 367 // bswap(bswap(x)) -> x 368 if (IntrinsicInst *Operand = dyn_cast<IntrinsicInst>(II->getOperand(1))) 369 if (Operand->getIntrinsicID() == Intrinsic::bswap) 370 return ReplaceInstUsesWith(CI, Operand->getOperand(1)); 371 372 // bswap(trunc(bswap(x))) -> trunc(lshr(x, c)) 373 if (TruncInst *TI = dyn_cast<TruncInst>(II->getOperand(1))) { 374 if (IntrinsicInst *Operand = dyn_cast<IntrinsicInst>(TI->getOperand(0))) 375 if (Operand->getIntrinsicID() == Intrinsic::bswap) { 376 unsigned C = Operand->getType()->getPrimitiveSizeInBits() - 377 TI->getType()->getPrimitiveSizeInBits(); 378 Value *CV = ConstantInt::get(Operand->getType(), C); 379 Value *V = Builder->CreateLShr(Operand->getOperand(1), CV); 380 return new TruncInst(V, TI->getType()); 381 } 382 } 383 384 break; 385 case Intrinsic::powi: 386 if (ConstantInt *Power = dyn_cast<ConstantInt>(II->getOperand(2))) { 387 // powi(x, 0) -> 1.0 388 if (Power->isZero()) 389 return ReplaceInstUsesWith(CI, ConstantFP::get(CI.getType(), 1.0)); 390 // powi(x, 1) -> x 391 if (Power->isOne()) 392 return ReplaceInstUsesWith(CI, II->getOperand(1)); 393 // powi(x, -1) -> 1/x 394 if (Power->isAllOnesValue()) 395 return BinaryOperator::CreateFDiv(ConstantFP::get(CI.getType(), 1.0), 396 II->getOperand(1)); 397 } 398 break; 399 case Intrinsic::cttz: { 400 // If all bits below the first known one are known zero, 401 // this value is constant. 402 const IntegerType *IT = cast<IntegerType>(II->getOperand(1)->getType()); 403 uint32_t BitWidth = IT->getBitWidth(); 404 APInt KnownZero(BitWidth, 0); 405 APInt KnownOne(BitWidth, 0); 406 ComputeMaskedBits(II->getOperand(1), APInt::getAllOnesValue(BitWidth), 407 KnownZero, KnownOne); 408 unsigned TrailingZeros = KnownOne.countTrailingZeros(); 409 APInt Mask(APInt::getLowBitsSet(BitWidth, TrailingZeros)); 410 if ((Mask & KnownZero) == Mask) 411 return ReplaceInstUsesWith(CI, ConstantInt::get(IT, 412 APInt(BitWidth, TrailingZeros))); 413 414 } 415 break; 416 case Intrinsic::ctlz: { 417 // If all bits above the first known one are known zero, 418 // this value is constant. 419 const IntegerType *IT = cast<IntegerType>(II->getOperand(1)->getType()); 420 uint32_t BitWidth = IT->getBitWidth(); 421 APInt KnownZero(BitWidth, 0); 422 APInt KnownOne(BitWidth, 0); 423 ComputeMaskedBits(II->getOperand(1), APInt::getAllOnesValue(BitWidth), 424 KnownZero, KnownOne); 425 unsigned LeadingZeros = KnownOne.countLeadingZeros(); 426 APInt Mask(APInt::getHighBitsSet(BitWidth, LeadingZeros)); 427 if ((Mask & KnownZero) == Mask) 428 return ReplaceInstUsesWith(CI, ConstantInt::get(IT, 429 APInt(BitWidth, LeadingZeros))); 430 431 } 432 break; 433 case Intrinsic::uadd_with_overflow: { 434 Value *LHS = II->getOperand(1), *RHS = II->getOperand(2); 435 const IntegerType *IT = cast<IntegerType>(II->getOperand(1)->getType()); 436 uint32_t BitWidth = IT->getBitWidth(); 437 APInt Mask = APInt::getSignBit(BitWidth); 438 APInt LHSKnownZero(BitWidth, 0); 439 APInt LHSKnownOne(BitWidth, 0); 440 ComputeMaskedBits(LHS, Mask, LHSKnownZero, LHSKnownOne); 441 bool LHSKnownNegative = LHSKnownOne[BitWidth - 1]; 442 bool LHSKnownPositive = LHSKnownZero[BitWidth - 1]; 443 444 if (LHSKnownNegative || LHSKnownPositive) { 445 APInt RHSKnownZero(BitWidth, 0); 446 APInt RHSKnownOne(BitWidth, 0); 447 ComputeMaskedBits(RHS, Mask, RHSKnownZero, RHSKnownOne); 448 bool RHSKnownNegative = RHSKnownOne[BitWidth - 1]; 449 bool RHSKnownPositive = RHSKnownZero[BitWidth - 1]; 450 if (LHSKnownNegative && RHSKnownNegative) { 451 // The sign bit is set in both cases: this MUST overflow. 452 // Create a simple add instruction, and insert it into the struct. 453 Instruction *Add = BinaryOperator::CreateAdd(LHS, RHS, "", &CI); 454 Worklist.Add(Add); 455 Constant *V[] = { 456 UndefValue::get(LHS->getType()),ConstantInt::getTrue(II->getContext()) 457 }; 458 Constant *Struct = ConstantStruct::get(II->getContext(), V, 2, false); 459 return InsertValueInst::Create(Struct, Add, 0); 460 } 461 462 if (LHSKnownPositive && RHSKnownPositive) { 463 // The sign bit is clear in both cases: this CANNOT overflow. 464 // Create a simple add instruction, and insert it into the struct. 465 Instruction *Add = BinaryOperator::CreateNUWAdd(LHS, RHS, "", &CI); 466 Worklist.Add(Add); 467 Constant *V[] = { 468 UndefValue::get(LHS->getType()), 469 ConstantInt::getFalse(II->getContext()) 470 }; 471 Constant *Struct = ConstantStruct::get(II->getContext(), V, 2, false); 472 return InsertValueInst::Create(Struct, Add, 0); 473 } 474 } 475 } 476 // FALL THROUGH uadd into sadd 477 case Intrinsic::sadd_with_overflow: 478 // Canonicalize constants into the RHS. 479 if (isa<Constant>(II->getOperand(1)) && 480 !isa<Constant>(II->getOperand(2))) { 481 Value *LHS = II->getOperand(1); 482 II->setOperand(1, II->getOperand(2)); 483 II->setOperand(2, LHS); 484 return II; 485 } 486 487 // X + undef -> undef 488 if (isa<UndefValue>(II->getOperand(2))) 489 return ReplaceInstUsesWith(CI, UndefValue::get(II->getType())); 490 491 if (ConstantInt *RHS = dyn_cast<ConstantInt>(II->getOperand(2))) { 492 // X + 0 -> {X, false} 493 if (RHS->isZero()) { 494 Constant *V[] = { 495 UndefValue::get(II->getOperand(0)->getType()), 496 ConstantInt::getFalse(II->getContext()) 497 }; 498 Constant *Struct = ConstantStruct::get(II->getContext(), V, 2, false); 499 return InsertValueInst::Create(Struct, II->getOperand(1), 0); 500 } 501 } 502 break; 503 case Intrinsic::usub_with_overflow: 504 case Intrinsic::ssub_with_overflow: 505 // undef - X -> undef 506 // X - undef -> undef 507 if (isa<UndefValue>(II->getOperand(1)) || 508 isa<UndefValue>(II->getOperand(2))) 509 return ReplaceInstUsesWith(CI, UndefValue::get(II->getType())); 510 511 if (ConstantInt *RHS = dyn_cast<ConstantInt>(II->getOperand(2))) { 512 // X - 0 -> {X, false} 513 if (RHS->isZero()) { 514 Constant *V[] = { 515 UndefValue::get(II->getOperand(1)->getType()), 516 ConstantInt::getFalse(II->getContext()) 517 }; 518 Constant *Struct = ConstantStruct::get(II->getContext(), V, 2, false); 519 return InsertValueInst::Create(Struct, II->getOperand(1), 0); 520 } 521 } 522 break; 523 case Intrinsic::umul_with_overflow: 524 case Intrinsic::smul_with_overflow: 525 // Canonicalize constants into the RHS. 526 if (isa<Constant>(II->getOperand(1)) && 527 !isa<Constant>(II->getOperand(2))) { 528 Value *LHS = II->getOperand(1); 529 II->setOperand(1, II->getOperand(2)); 530 II->setOperand(2, LHS); 531 return II; 532 } 533 534 // X * undef -> undef 535 if (isa<UndefValue>(II->getOperand(2))) 536 return ReplaceInstUsesWith(CI, UndefValue::get(II->getType())); 537 538 if (ConstantInt *RHSI = dyn_cast<ConstantInt>(II->getOperand(2))) { 539 // X*0 -> {0, false} 540 if (RHSI->isZero()) 541 return ReplaceInstUsesWith(CI, Constant::getNullValue(II->getType())); 542 543 // X * 1 -> {X, false} 544 if (RHSI->equalsInt(1)) { 545 Constant *V[] = { 546 UndefValue::get(II->getOperand(1)->getType()), 547 ConstantInt::getFalse(II->getContext()) 548 }; 549 Constant *Struct = ConstantStruct::get(II->getContext(), V, 2, false); 550 return InsertValueInst::Create(Struct, II->getOperand(1), 0); 551 } 552 } 553 break; 554 case Intrinsic::ppc_altivec_lvx: 555 case Intrinsic::ppc_altivec_lvxl: 556 case Intrinsic::x86_sse_loadu_ps: 557 case Intrinsic::x86_sse2_loadu_pd: 558 case Intrinsic::x86_sse2_loadu_dq: 559 // Turn PPC lvx -> load if the pointer is known aligned. 560 // Turn X86 loadups -> load if the pointer is known aligned. 561 if (GetOrEnforceKnownAlignment(II->getOperand(1), 16) >= 16) { 562 Value *Ptr = Builder->CreateBitCast(II->getOperand(1), 563 PointerType::getUnqual(II->getType())); 564 return new LoadInst(Ptr); 565 } 566 break; 567 case Intrinsic::ppc_altivec_stvx: 568 case Intrinsic::ppc_altivec_stvxl: 569 // Turn stvx -> store if the pointer is known aligned. 570 if (GetOrEnforceKnownAlignment(II->getOperand(2), 16) >= 16) { 571 const Type *OpPtrTy = 572 PointerType::getUnqual(II->getOperand(1)->getType()); 573 Value *Ptr = Builder->CreateBitCast(II->getOperand(2), OpPtrTy); 574 return new StoreInst(II->getOperand(1), Ptr); 575 } 576 break; 577 case Intrinsic::x86_sse_storeu_ps: 578 case Intrinsic::x86_sse2_storeu_pd: 579 case Intrinsic::x86_sse2_storeu_dq: 580 // Turn X86 storeu -> store if the pointer is known aligned. 581 if (GetOrEnforceKnownAlignment(II->getOperand(1), 16) >= 16) { 582 const Type *OpPtrTy = 583 PointerType::getUnqual(II->getOperand(2)->getType()); 584 Value *Ptr = Builder->CreateBitCast(II->getOperand(1), OpPtrTy); 585 return new StoreInst(II->getOperand(2), Ptr); 586 } 587 break; 588 589 case Intrinsic::x86_sse_cvttss2si: { 590 // These intrinsics only demands the 0th element of its input vector. If 591 // we can simplify the input based on that, do so now. 592 unsigned VWidth = 593 cast<VectorType>(II->getOperand(1)->getType())->getNumElements(); 594 APInt DemandedElts(VWidth, 1); 595 APInt UndefElts(VWidth, 0); 596 if (Value *V = SimplifyDemandedVectorElts(II->getOperand(1), DemandedElts, 597 UndefElts)) { 598 II->setOperand(1, V); 599 return II; 600 } 601 break; 602 } 603 604 case Intrinsic::ppc_altivec_vperm: 605 // Turn vperm(V1,V2,mask) -> shuffle(V1,V2,mask) if mask is a constant. 606 if (ConstantVector *Mask = dyn_cast<ConstantVector>(II->getOperand(3))) { 607 assert(Mask->getNumOperands() == 16 && "Bad type for intrinsic!"); 608 609 // Check that all of the elements are integer constants or undefs. 610 bool AllEltsOk = true; 611 for (unsigned i = 0; i != 16; ++i) { 612 if (!isa<ConstantInt>(Mask->getOperand(i)) && 613 !isa<UndefValue>(Mask->getOperand(i))) { 614 AllEltsOk = false; 615 break; 616 } 617 } 618 619 if (AllEltsOk) { 620 // Cast the input vectors to byte vectors. 621 Value *Op0 = Builder->CreateBitCast(II->getOperand(1), Mask->getType()); 622 Value *Op1 = Builder->CreateBitCast(II->getOperand(2), Mask->getType()); 623 Value *Result = UndefValue::get(Op0->getType()); 624 625 // Only extract each element once. 626 Value *ExtractedElts[32]; 627 memset(ExtractedElts, 0, sizeof(ExtractedElts)); 628 629 for (unsigned i = 0; i != 16; ++i) { 630 if (isa<UndefValue>(Mask->getOperand(i))) 631 continue; 632 unsigned Idx=cast<ConstantInt>(Mask->getOperand(i))->getZExtValue(); 633 Idx &= 31; // Match the hardware behavior. 634 635 if (ExtractedElts[Idx] == 0) { 636 ExtractedElts[Idx] = 637 Builder->CreateExtractElement(Idx < 16 ? Op0 : Op1, 638 ConstantInt::get(Type::getInt32Ty(II->getContext()), 639 Idx&15, false), "tmp"); 640 } 641 642 // Insert this value into the result vector. 643 Result = Builder->CreateInsertElement(Result, ExtractedElts[Idx], 644 ConstantInt::get(Type::getInt32Ty(II->getContext()), 645 i, false), "tmp"); 646 } 647 return CastInst::Create(Instruction::BitCast, Result, CI.getType()); 648 } 649 } 650 break; 651 652 case Intrinsic::stackrestore: { 653 // If the save is right next to the restore, remove the restore. This can 654 // happen when variable allocas are DCE'd. 655 if (IntrinsicInst *SS = dyn_cast<IntrinsicInst>(II->getOperand(1))) { 656 if (SS->getIntrinsicID() == Intrinsic::stacksave) { 657 BasicBlock::iterator BI = SS; 658 if (&*++BI == II) 659 return EraseInstFromFunction(CI); 660 } 661 } 662 663 // Scan down this block to see if there is another stack restore in the 664 // same block without an intervening call/alloca. 665 BasicBlock::iterator BI = II; 666 TerminatorInst *TI = II->getParent()->getTerminator(); 667 bool CannotRemove = false; 668 for (++BI; &*BI != TI; ++BI) { 669 if (isa<AllocaInst>(BI) || isMalloc(BI)) { 670 CannotRemove = true; 671 break; 672 } 673 if (CallInst *BCI = dyn_cast<CallInst>(BI)) { 674 if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(BCI)) { 675 // If there is a stackrestore below this one, remove this one. 676 if (II->getIntrinsicID() == Intrinsic::stackrestore) 677 return EraseInstFromFunction(CI); 678 // Otherwise, ignore the intrinsic. 679 } else { 680 // If we found a non-intrinsic call, we can't remove the stack 681 // restore. 682 CannotRemove = true; 683 break; 684 } 685 } 686 } 687 688 // If the stack restore is in a return/unwind block and if there are no 689 // allocas or calls between the restore and the return, nuke the restore. 690 if (!CannotRemove && (isa<ReturnInst>(TI) || isa<UnwindInst>(TI))) 691 return EraseInstFromFunction(CI); 692 break; 693 } 694 } 695 696 return visitCallSite(II); 697} 698 699// InvokeInst simplification 700// 701Instruction *InstCombiner::visitInvokeInst(InvokeInst &II) { 702 return visitCallSite(&II); 703} 704 705/// isSafeToEliminateVarargsCast - If this cast does not affect the value 706/// passed through the varargs area, we can eliminate the use of the cast. 707static bool isSafeToEliminateVarargsCast(const CallSite CS, 708 const CastInst * const CI, 709 const TargetData * const TD, 710 const int ix) { 711 if (!CI->isLosslessCast()) 712 return false; 713 714 // The size of ByVal arguments is derived from the type, so we 715 // can't change to a type with a different size. If the size were 716 // passed explicitly we could avoid this check. 717 if (!CS.paramHasAttr(ix, Attribute::ByVal)) 718 return true; 719 720 const Type* SrcTy = 721 cast<PointerType>(CI->getOperand(0)->getType())->getElementType(); 722 const Type* DstTy = cast<PointerType>(CI->getType())->getElementType(); 723 if (!SrcTy->isSized() || !DstTy->isSized()) 724 return false; 725 if (!TD || TD->getTypeAllocSize(SrcTy) != TD->getTypeAllocSize(DstTy)) 726 return false; 727 return true; 728} 729 730// visitCallSite - Improvements for call and invoke instructions. 731// 732Instruction *InstCombiner::visitCallSite(CallSite CS) { 733 bool Changed = false; 734 735 // If the callee is a constexpr cast of a function, attempt to move the cast 736 // to the arguments of the call/invoke. 737 if (transformConstExprCastCall(CS)) return 0; 738 739 Value *Callee = CS.getCalledValue(); 740 741 if (Function *CalleeF = dyn_cast<Function>(Callee)) 742 // If the call and callee calling conventions don't match, this call must 743 // be unreachable, as the call is undefined. 744 if (CalleeF->getCallingConv() != CS.getCallingConv() && 745 // Only do this for calls to a function with a body. A prototype may 746 // not actually end up matching the implementation's calling conv for a 747 // variety of reasons (e.g. it may be written in assembly). 748 !CalleeF->isDeclaration()) { 749 Instruction *OldCall = CS.getInstruction(); 750 new StoreInst(ConstantInt::getTrue(Callee->getContext()), 751 UndefValue::get(Type::getInt1PtrTy(Callee->getContext())), 752 OldCall); 753 // If OldCall dues not return void then replaceAllUsesWith undef. 754 // This allows ValueHandlers and custom metadata to adjust itself. 755 if (!OldCall->getType()->isVoidTy()) 756 OldCall->replaceAllUsesWith(UndefValue::get(OldCall->getType())); 757 if (isa<CallInst>(OldCall)) 758 return EraseInstFromFunction(*OldCall); 759 760 // We cannot remove an invoke, because it would change the CFG, just 761 // change the callee to a null pointer. 762 cast<InvokeInst>(OldCall)->setOperand(0, 763 Constant::getNullValue(CalleeF->getType())); 764 return 0; 765 } 766 767 if (isa<ConstantPointerNull>(Callee) || isa<UndefValue>(Callee)) { 768 // This instruction is not reachable, just remove it. We insert a store to 769 // undef so that we know that this code is not reachable, despite the fact 770 // that we can't modify the CFG here. 771 new StoreInst(ConstantInt::getTrue(Callee->getContext()), 772 UndefValue::get(Type::getInt1PtrTy(Callee->getContext())), 773 CS.getInstruction()); 774 775 // If CS dues not return void then replaceAllUsesWith undef. 776 // This allows ValueHandlers and custom metadata to adjust itself. 777 if (!CS.getInstruction()->getType()->isVoidTy()) 778 CS.getInstruction()-> 779 replaceAllUsesWith(UndefValue::get(CS.getInstruction()->getType())); 780 781 if (InvokeInst *II = dyn_cast<InvokeInst>(CS.getInstruction())) { 782 // Don't break the CFG, insert a dummy cond branch. 783 BranchInst::Create(II->getNormalDest(), II->getUnwindDest(), 784 ConstantInt::getTrue(Callee->getContext()), II); 785 } 786 return EraseInstFromFunction(*CS.getInstruction()); 787 } 788 789 if (BitCastInst *BC = dyn_cast<BitCastInst>(Callee)) 790 if (IntrinsicInst *In = dyn_cast<IntrinsicInst>(BC->getOperand(0))) 791 if (In->getIntrinsicID() == Intrinsic::init_trampoline) 792 return transformCallThroughTrampoline(CS); 793 794 const PointerType *PTy = cast<PointerType>(Callee->getType()); 795 const FunctionType *FTy = cast<FunctionType>(PTy->getElementType()); 796 if (FTy->isVarArg()) { 797 int ix = FTy->getNumParams() + (isa<InvokeInst>(Callee) ? 3 : 1); 798 // See if we can optimize any arguments passed through the varargs area of 799 // the call. 800 for (CallSite::arg_iterator I = CS.arg_begin()+FTy->getNumParams(), 801 E = CS.arg_end(); I != E; ++I, ++ix) { 802 CastInst *CI = dyn_cast<CastInst>(*I); 803 if (CI && isSafeToEliminateVarargsCast(CS, CI, TD, ix)) { 804 *I = CI->getOperand(0); 805 Changed = true; 806 } 807 } 808 } 809 810 if (isa<InlineAsm>(Callee) && !CS.doesNotThrow()) { 811 // Inline asm calls cannot throw - mark them 'nounwind'. 812 CS.setDoesNotThrow(); 813 Changed = true; 814 } 815 816 return Changed ? CS.getInstruction() : 0; 817} 818 819// transformConstExprCastCall - If the callee is a constexpr cast of a function, 820// attempt to move the cast to the arguments of the call/invoke. 821// 822bool InstCombiner::transformConstExprCastCall(CallSite CS) { 823 if (!isa<ConstantExpr>(CS.getCalledValue())) return false; 824 ConstantExpr *CE = cast<ConstantExpr>(CS.getCalledValue()); 825 if (CE->getOpcode() != Instruction::BitCast || 826 !isa<Function>(CE->getOperand(0))) 827 return false; 828 Function *Callee = cast<Function>(CE->getOperand(0)); 829 Instruction *Caller = CS.getInstruction(); 830 const AttrListPtr &CallerPAL = CS.getAttributes(); 831 832 // Okay, this is a cast from a function to a different type. Unless doing so 833 // would cause a type conversion of one of our arguments, change this call to 834 // be a direct call with arguments casted to the appropriate types. 835 // 836 const FunctionType *FT = Callee->getFunctionType(); 837 const Type *OldRetTy = Caller->getType(); 838 const Type *NewRetTy = FT->getReturnType(); 839 840 if (NewRetTy->isStructTy()) 841 return false; // TODO: Handle multiple return values. 842 843 // Check to see if we are changing the return type... 844 if (OldRetTy != NewRetTy) { 845 if (Callee->isDeclaration() && 846 // Conversion is ok if changing from one pointer type to another or from 847 // a pointer to an integer of the same size. 848 !((OldRetTy->isPointerTy() || !TD || 849 OldRetTy == TD->getIntPtrType(Caller->getContext())) && 850 (NewRetTy->isPointerTy() || !TD || 851 NewRetTy == TD->getIntPtrType(Caller->getContext())))) 852 return false; // Cannot transform this return value. 853 854 if (!Caller->use_empty() && 855 // void -> non-void is handled specially 856 !NewRetTy->isVoidTy() && !CastInst::isCastable(NewRetTy, OldRetTy)) 857 return false; // Cannot transform this return value. 858 859 if (!CallerPAL.isEmpty() && !Caller->use_empty()) { 860 Attributes RAttrs = CallerPAL.getRetAttributes(); 861 if (RAttrs & Attribute::typeIncompatible(NewRetTy)) 862 return false; // Attribute not compatible with transformed value. 863 } 864 865 // If the callsite is an invoke instruction, and the return value is used by 866 // a PHI node in a successor, we cannot change the return type of the call 867 // because there is no place to put the cast instruction (without breaking 868 // the critical edge). Bail out in this case. 869 if (!Caller->use_empty()) 870 if (InvokeInst *II = dyn_cast<InvokeInst>(Caller)) 871 for (Value::use_iterator UI = II->use_begin(), E = II->use_end(); 872 UI != E; ++UI) 873 if (PHINode *PN = dyn_cast<PHINode>(*UI)) 874 if (PN->getParent() == II->getNormalDest() || 875 PN->getParent() == II->getUnwindDest()) 876 return false; 877 } 878 879 unsigned NumActualArgs = unsigned(CS.arg_end()-CS.arg_begin()); 880 unsigned NumCommonArgs = std::min(FT->getNumParams(), NumActualArgs); 881 882 CallSite::arg_iterator AI = CS.arg_begin(); 883 for (unsigned i = 0, e = NumCommonArgs; i != e; ++i, ++AI) { 884 const Type *ParamTy = FT->getParamType(i); 885 const Type *ActTy = (*AI)->getType(); 886 887 if (!CastInst::isCastable(ActTy, ParamTy)) 888 return false; // Cannot transform this parameter value. 889 890 if (CallerPAL.getParamAttributes(i + 1) 891 & Attribute::typeIncompatible(ParamTy)) 892 return false; // Attribute not compatible with transformed value. 893 894 // Converting from one pointer type to another or between a pointer and an 895 // integer of the same size is safe even if we do not have a body. 896 bool isConvertible = ActTy == ParamTy || 897 (TD && ((ParamTy->isPointerTy() || 898 ParamTy == TD->getIntPtrType(Caller->getContext())) && 899 (ActTy->isPointerTy() || 900 ActTy == TD->getIntPtrType(Caller->getContext())))); 901 if (Callee->isDeclaration() && !isConvertible) return false; 902 } 903 904 if (FT->getNumParams() < NumActualArgs && !FT->isVarArg() && 905 Callee->isDeclaration()) 906 return false; // Do not delete arguments unless we have a function body. 907 908 if (FT->getNumParams() < NumActualArgs && FT->isVarArg() && 909 !CallerPAL.isEmpty()) 910 // In this case we have more arguments than the new function type, but we 911 // won't be dropping them. Check that these extra arguments have attributes 912 // that are compatible with being a vararg call argument. 913 for (unsigned i = CallerPAL.getNumSlots(); i; --i) { 914 if (CallerPAL.getSlot(i - 1).Index <= FT->getNumParams()) 915 break; 916 Attributes PAttrs = CallerPAL.getSlot(i - 1).Attrs; 917 if (PAttrs & Attribute::VarArgsIncompatible) 918 return false; 919 } 920 921 // Okay, we decided that this is a safe thing to do: go ahead and start 922 // inserting cast instructions as necessary... 923 std::vector<Value*> Args; 924 Args.reserve(NumActualArgs); 925 SmallVector<AttributeWithIndex, 8> attrVec; 926 attrVec.reserve(NumCommonArgs); 927 928 // Get any return attributes. 929 Attributes RAttrs = CallerPAL.getRetAttributes(); 930 931 // If the return value is not being used, the type may not be compatible 932 // with the existing attributes. Wipe out any problematic attributes. 933 RAttrs &= ~Attribute::typeIncompatible(NewRetTy); 934 935 // Add the new return attributes. 936 if (RAttrs) 937 attrVec.push_back(AttributeWithIndex::get(0, RAttrs)); 938 939 AI = CS.arg_begin(); 940 for (unsigned i = 0; i != NumCommonArgs; ++i, ++AI) { 941 const Type *ParamTy = FT->getParamType(i); 942 if ((*AI)->getType() == ParamTy) { 943 Args.push_back(*AI); 944 } else { 945 Instruction::CastOps opcode = CastInst::getCastOpcode(*AI, 946 false, ParamTy, false); 947 Args.push_back(Builder->CreateCast(opcode, *AI, ParamTy, "tmp")); 948 } 949 950 // Add any parameter attributes. 951 if (Attributes PAttrs = CallerPAL.getParamAttributes(i + 1)) 952 attrVec.push_back(AttributeWithIndex::get(i + 1, PAttrs)); 953 } 954 955 // If the function takes more arguments than the call was taking, add them 956 // now. 957 for (unsigned i = NumCommonArgs; i != FT->getNumParams(); ++i) 958 Args.push_back(Constant::getNullValue(FT->getParamType(i))); 959 960 // If we are removing arguments to the function, emit an obnoxious warning. 961 if (FT->getNumParams() < NumActualArgs) { 962 if (!FT->isVarArg()) { 963 errs() << "WARNING: While resolving call to function '" 964 << Callee->getName() << "' arguments were dropped!\n"; 965 } else { 966 // Add all of the arguments in their promoted form to the arg list. 967 for (unsigned i = FT->getNumParams(); i != NumActualArgs; ++i, ++AI) { 968 const Type *PTy = getPromotedType((*AI)->getType()); 969 if (PTy != (*AI)->getType()) { 970 // Must promote to pass through va_arg area! 971 Instruction::CastOps opcode = 972 CastInst::getCastOpcode(*AI, false, PTy, false); 973 Args.push_back(Builder->CreateCast(opcode, *AI, PTy, "tmp")); 974 } else { 975 Args.push_back(*AI); 976 } 977 978 // Add any parameter attributes. 979 if (Attributes PAttrs = CallerPAL.getParamAttributes(i + 1)) 980 attrVec.push_back(AttributeWithIndex::get(i + 1, PAttrs)); 981 } 982 } 983 } 984 985 if (Attributes FnAttrs = CallerPAL.getFnAttributes()) 986 attrVec.push_back(AttributeWithIndex::get(~0, FnAttrs)); 987 988 if (NewRetTy->isVoidTy()) 989 Caller->setName(""); // Void type should not have a name. 990 991 const AttrListPtr &NewCallerPAL = AttrListPtr::get(attrVec.begin(), 992 attrVec.end()); 993 994 Instruction *NC; 995 if (InvokeInst *II = dyn_cast<InvokeInst>(Caller)) { 996 NC = InvokeInst::Create(Callee, II->getNormalDest(), II->getUnwindDest(), 997 Args.begin(), Args.end(), 998 Caller->getName(), Caller); 999 cast<InvokeInst>(NC)->setCallingConv(II->getCallingConv()); 1000 cast<InvokeInst>(NC)->setAttributes(NewCallerPAL); 1001 } else { 1002 NC = CallInst::Create(Callee, Args.begin(), Args.end(), 1003 Caller->getName(), Caller); 1004 CallInst *CI = cast<CallInst>(Caller); 1005 if (CI->isTailCall()) 1006 cast<CallInst>(NC)->setTailCall(); 1007 cast<CallInst>(NC)->setCallingConv(CI->getCallingConv()); 1008 cast<CallInst>(NC)->setAttributes(NewCallerPAL); 1009 } 1010 1011 // Insert a cast of the return type as necessary. 1012 Value *NV = NC; 1013 if (OldRetTy != NV->getType() && !Caller->use_empty()) { 1014 if (!NV->getType()->isVoidTy()) { 1015 Instruction::CastOps opcode = CastInst::getCastOpcode(NC, false, 1016 OldRetTy, false); 1017 NV = NC = CastInst::Create(opcode, NC, OldRetTy, "tmp"); 1018 1019 // If this is an invoke instruction, we should insert it after the first 1020 // non-phi, instruction in the normal successor block. 1021 if (InvokeInst *II = dyn_cast<InvokeInst>(Caller)) { 1022 BasicBlock::iterator I = II->getNormalDest()->getFirstNonPHI(); 1023 InsertNewInstBefore(NC, *I); 1024 } else { 1025 // Otherwise, it's a call, just insert cast right after the call instr 1026 InsertNewInstBefore(NC, *Caller); 1027 } 1028 Worklist.AddUsersToWorkList(*Caller); 1029 } else { 1030 NV = UndefValue::get(Caller->getType()); 1031 } 1032 } 1033 1034 1035 if (!Caller->use_empty()) 1036 Caller->replaceAllUsesWith(NV); 1037 1038 EraseInstFromFunction(*Caller); 1039 return true; 1040} 1041 1042// transformCallThroughTrampoline - Turn a call to a function created by the 1043// init_trampoline intrinsic into a direct call to the underlying function. 1044// 1045Instruction *InstCombiner::transformCallThroughTrampoline(CallSite CS) { 1046 Value *Callee = CS.getCalledValue(); 1047 const PointerType *PTy = cast<PointerType>(Callee->getType()); 1048 const FunctionType *FTy = cast<FunctionType>(PTy->getElementType()); 1049 const AttrListPtr &Attrs = CS.getAttributes(); 1050 1051 // If the call already has the 'nest' attribute somewhere then give up - 1052 // otherwise 'nest' would occur twice after splicing in the chain. 1053 if (Attrs.hasAttrSomewhere(Attribute::Nest)) 1054 return 0; 1055 1056 IntrinsicInst *Tramp = 1057 cast<IntrinsicInst>(cast<BitCastInst>(Callee)->getOperand(0)); 1058 1059 Function *NestF = cast<Function>(Tramp->getOperand(2)->stripPointerCasts()); 1060 const PointerType *NestFPTy = cast<PointerType>(NestF->getType()); 1061 const FunctionType *NestFTy = cast<FunctionType>(NestFPTy->getElementType()); 1062 1063 const AttrListPtr &NestAttrs = NestF->getAttributes(); 1064 if (!NestAttrs.isEmpty()) { 1065 unsigned NestIdx = 1; 1066 const Type *NestTy = 0; 1067 Attributes NestAttr = Attribute::None; 1068 1069 // Look for a parameter marked with the 'nest' attribute. 1070 for (FunctionType::param_iterator I = NestFTy->param_begin(), 1071 E = NestFTy->param_end(); I != E; ++NestIdx, ++I) 1072 if (NestAttrs.paramHasAttr(NestIdx, Attribute::Nest)) { 1073 // Record the parameter type and any other attributes. 1074 NestTy = *I; 1075 NestAttr = NestAttrs.getParamAttributes(NestIdx); 1076 break; 1077 } 1078 1079 if (NestTy) { 1080 Instruction *Caller = CS.getInstruction(); 1081 std::vector<Value*> NewArgs; 1082 NewArgs.reserve(unsigned(CS.arg_end()-CS.arg_begin())+1); 1083 1084 SmallVector<AttributeWithIndex, 8> NewAttrs; 1085 NewAttrs.reserve(Attrs.getNumSlots() + 1); 1086 1087 // Insert the nest argument into the call argument list, which may 1088 // mean appending it. Likewise for attributes. 1089 1090 // Add any result attributes. 1091 if (Attributes Attr = Attrs.getRetAttributes()) 1092 NewAttrs.push_back(AttributeWithIndex::get(0, Attr)); 1093 1094 { 1095 unsigned Idx = 1; 1096 CallSite::arg_iterator I = CS.arg_begin(), E = CS.arg_end(); 1097 do { 1098 if (Idx == NestIdx) { 1099 // Add the chain argument and attributes. 1100 Value *NestVal = Tramp->getOperand(3); 1101 if (NestVal->getType() != NestTy) 1102 NestVal = new BitCastInst(NestVal, NestTy, "nest", Caller); 1103 NewArgs.push_back(NestVal); 1104 NewAttrs.push_back(AttributeWithIndex::get(NestIdx, NestAttr)); 1105 } 1106 1107 if (I == E) 1108 break; 1109 1110 // Add the original argument and attributes. 1111 NewArgs.push_back(*I); 1112 if (Attributes Attr = Attrs.getParamAttributes(Idx)) 1113 NewAttrs.push_back 1114 (AttributeWithIndex::get(Idx + (Idx >= NestIdx), Attr)); 1115 1116 ++Idx, ++I; 1117 } while (1); 1118 } 1119 1120 // Add any function attributes. 1121 if (Attributes Attr = Attrs.getFnAttributes()) 1122 NewAttrs.push_back(AttributeWithIndex::get(~0, Attr)); 1123 1124 // The trampoline may have been bitcast to a bogus type (FTy). 1125 // Handle this by synthesizing a new function type, equal to FTy 1126 // with the chain parameter inserted. 1127 1128 std::vector<const Type*> NewTypes; 1129 NewTypes.reserve(FTy->getNumParams()+1); 1130 1131 // Insert the chain's type into the list of parameter types, which may 1132 // mean appending it. 1133 { 1134 unsigned Idx = 1; 1135 FunctionType::param_iterator I = FTy->param_begin(), 1136 E = FTy->param_end(); 1137 1138 do { 1139 if (Idx == NestIdx) 1140 // Add the chain's type. 1141 NewTypes.push_back(NestTy); 1142 1143 if (I == E) 1144 break; 1145 1146 // Add the original type. 1147 NewTypes.push_back(*I); 1148 1149 ++Idx, ++I; 1150 } while (1); 1151 } 1152 1153 // Replace the trampoline call with a direct call. Let the generic 1154 // code sort out any function type mismatches. 1155 FunctionType *NewFTy = FunctionType::get(FTy->getReturnType(), NewTypes, 1156 FTy->isVarArg()); 1157 Constant *NewCallee = 1158 NestF->getType() == PointerType::getUnqual(NewFTy) ? 1159 NestF : ConstantExpr::getBitCast(NestF, 1160 PointerType::getUnqual(NewFTy)); 1161 const AttrListPtr &NewPAL = AttrListPtr::get(NewAttrs.begin(), 1162 NewAttrs.end()); 1163 1164 Instruction *NewCaller; 1165 if (InvokeInst *II = dyn_cast<InvokeInst>(Caller)) { 1166 NewCaller = InvokeInst::Create(NewCallee, 1167 II->getNormalDest(), II->getUnwindDest(), 1168 NewArgs.begin(), NewArgs.end(), 1169 Caller->getName(), Caller); 1170 cast<InvokeInst>(NewCaller)->setCallingConv(II->getCallingConv()); 1171 cast<InvokeInst>(NewCaller)->setAttributes(NewPAL); 1172 } else { 1173 NewCaller = CallInst::Create(NewCallee, NewArgs.begin(), NewArgs.end(), 1174 Caller->getName(), Caller); 1175 if (cast<CallInst>(Caller)->isTailCall()) 1176 cast<CallInst>(NewCaller)->setTailCall(); 1177 cast<CallInst>(NewCaller)-> 1178 setCallingConv(cast<CallInst>(Caller)->getCallingConv()); 1179 cast<CallInst>(NewCaller)->setAttributes(NewPAL); 1180 } 1181 if (!Caller->getType()->isVoidTy()) 1182 Caller->replaceAllUsesWith(NewCaller); 1183 Caller->eraseFromParent(); 1184 Worklist.Remove(Caller); 1185 return 0; 1186 } 1187 } 1188 1189 // Replace the trampoline call with a direct call. Since there is no 'nest' 1190 // parameter, there is no need to adjust the argument list. Let the generic 1191 // code sort out any function type mismatches. 1192 Constant *NewCallee = 1193 NestF->getType() == PTy ? NestF : 1194 ConstantExpr::getBitCast(NestF, PTy); 1195 CS.setCalledFunction(NewCallee); 1196 return CS.getInstruction(); 1197} 1198 1199