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/ADT/Statistic.h" 16 #include "llvm/Analysis/MemoryBuiltins.h" 17 #include "llvm/IR/DataLayout.h" 18 #include "llvm/Support/CallSite.h" 19 #include "llvm/Support/PatternMatch.h" 20 #include "llvm/Transforms/Utils/BuildLibCalls.h" 21 #include "llvm/Transforms/Utils/Local.h" 22 using namespace llvm; 23 using namespace PatternMatch; 24 25 STATISTIC(NumSimplified, "Number of library calls simplified"); 26 27 /// getPromotedType - Return the specified type promoted as it would be to pass 28 /// though a va_arg area. 29 static Type *getPromotedType(Type *Ty) { 30 if (IntegerType* ITy = dyn_cast<IntegerType>(Ty)) { 31 if (ITy->getBitWidth() < 32) 32 return Type::getInt32Ty(Ty->getContext()); 33 } 34 return Ty; 35 } 36 37 /// reduceToSingleValueType - Given an aggregate type which ultimately holds a 38 /// single scalar element, like {{{type}}} or [1 x type], return type. 39 static Type *reduceToSingleValueType(Type *T) { 40 while (!T->isSingleValueType()) { 41 if (StructType *STy = dyn_cast<StructType>(T)) { 42 if (STy->getNumElements() == 1) 43 T = STy->getElementType(0); 44 else 45 break; 46 } else if (ArrayType *ATy = dyn_cast<ArrayType>(T)) { 47 if (ATy->getNumElements() == 1) 48 T = ATy->getElementType(); 49 else 50 break; 51 } else 52 break; 53 } 54 55 return T; 56 } 57 58 Instruction *InstCombiner::SimplifyMemTransfer(MemIntrinsic *MI) { 59 unsigned DstAlign = getKnownAlignment(MI->getArgOperand(0), TD); 60 unsigned SrcAlign = getKnownAlignment(MI->getArgOperand(1), TD); 61 unsigned MinAlign = std::min(DstAlign, SrcAlign); 62 unsigned CopyAlign = MI->getAlignment(); 63 64 if (CopyAlign < MinAlign) { 65 MI->setAlignment(ConstantInt::get(MI->getAlignmentType(), 66 MinAlign, false)); 67 return MI; 68 } 69 70 // If MemCpyInst length is 1/2/4/8 bytes then replace memcpy with 71 // load/store. 72 ConstantInt *MemOpLength = dyn_cast<ConstantInt>(MI->getArgOperand(2)); 73 if (MemOpLength == 0) return 0; 74 75 // Source and destination pointer types are always "i8*" for intrinsic. See 76 // if the size is something we can handle with a single primitive load/store. 77 // A single load+store correctly handles overlapping memory in the memmove 78 // case. 79 uint64_t Size = MemOpLength->getLimitedValue(); 80 assert(Size && "0-sized memory transfering should be removed already."); 81 82 if (Size > 8 || (Size&(Size-1))) 83 return 0; // If not 1/2/4/8 bytes, exit. 84 85 // Use an integer load+store unless we can find something better. 86 unsigned SrcAddrSp = 87 cast<PointerType>(MI->getArgOperand(1)->getType())->getAddressSpace(); 88 unsigned DstAddrSp = 89 cast<PointerType>(MI->getArgOperand(0)->getType())->getAddressSpace(); 90 91 IntegerType* IntType = IntegerType::get(MI->getContext(), Size<<3); 92 Type *NewSrcPtrTy = PointerType::get(IntType, SrcAddrSp); 93 Type *NewDstPtrTy = PointerType::get(IntType, DstAddrSp); 94 95 // Memcpy forces the use of i8* for the source and destination. That means 96 // that if you're using memcpy to move one double around, you'll get a cast 97 // from double* to i8*. We'd much rather use a double load+store rather than 98 // an i64 load+store, here because this improves the odds that the source or 99 // dest address will be promotable. See if we can find a better type than the 100 // integer datatype. 101 Value *StrippedDest = MI->getArgOperand(0)->stripPointerCasts(); 102 MDNode *CopyMD = 0; 103 if (StrippedDest != MI->getArgOperand(0)) { 104 Type *SrcETy = cast<PointerType>(StrippedDest->getType()) 105 ->getElementType(); 106 if (TD && SrcETy->isSized() && TD->getTypeStoreSize(SrcETy) == Size) { 107 // The SrcETy might be something like {{{double}}} or [1 x double]. Rip 108 // down through these levels if so. 109 SrcETy = reduceToSingleValueType(SrcETy); 110 111 if (SrcETy->isSingleValueType()) { 112 NewSrcPtrTy = PointerType::get(SrcETy, SrcAddrSp); 113 NewDstPtrTy = PointerType::get(SrcETy, DstAddrSp); 114 115 // If the memcpy has metadata describing the members, see if we can 116 // get the TBAA tag describing our copy. 117 if (MDNode *M = MI->getMetadata(LLVMContext::MD_tbaa_struct)) { 118 if (M->getNumOperands() == 3 && 119 M->getOperand(0) && 120 isa<ConstantInt>(M->getOperand(0)) && 121 cast<ConstantInt>(M->getOperand(0))->isNullValue() && 122 M->getOperand(1) && 123 isa<ConstantInt>(M->getOperand(1)) && 124 cast<ConstantInt>(M->getOperand(1))->getValue() == Size && 125 M->getOperand(2) && 126 isa<MDNode>(M->getOperand(2))) 127 CopyMD = cast<MDNode>(M->getOperand(2)); 128 } 129 } 130 } 131 } 132 133 // If the memcpy/memmove provides better alignment info than we can 134 // infer, use it. 135 SrcAlign = std::max(SrcAlign, CopyAlign); 136 DstAlign = std::max(DstAlign, CopyAlign); 137 138 Value *Src = Builder->CreateBitCast(MI->getArgOperand(1), NewSrcPtrTy); 139 Value *Dest = Builder->CreateBitCast(MI->getArgOperand(0), NewDstPtrTy); 140 LoadInst *L = Builder->CreateLoad(Src, MI->isVolatile()); 141 L->setAlignment(SrcAlign); 142 if (CopyMD) 143 L->setMetadata(LLVMContext::MD_tbaa, CopyMD); 144 StoreInst *S = Builder->CreateStore(L, Dest, MI->isVolatile()); 145 S->setAlignment(DstAlign); 146 if (CopyMD) 147 S->setMetadata(LLVMContext::MD_tbaa, CopyMD); 148 149 // Set the size of the copy to 0, it will be deleted on the next iteration. 150 MI->setArgOperand(2, Constant::getNullValue(MemOpLength->getType())); 151 return MI; 152 } 153 154 Instruction *InstCombiner::SimplifyMemSet(MemSetInst *MI) { 155 unsigned Alignment = getKnownAlignment(MI->getDest(), TD); 156 if (MI->getAlignment() < Alignment) { 157 MI->setAlignment(ConstantInt::get(MI->getAlignmentType(), 158 Alignment, false)); 159 return MI; 160 } 161 162 // Extract the length and alignment and fill if they are constant. 163 ConstantInt *LenC = dyn_cast<ConstantInt>(MI->getLength()); 164 ConstantInt *FillC = dyn_cast<ConstantInt>(MI->getValue()); 165 if (!LenC || !FillC || !FillC->getType()->isIntegerTy(8)) 166 return 0; 167 uint64_t Len = LenC->getLimitedValue(); 168 Alignment = MI->getAlignment(); 169 assert(Len && "0-sized memory setting should be removed already."); 170 171 // memset(s,c,n) -> store s, c (for n=1,2,4,8) 172 if (Len <= 8 && isPowerOf2_32((uint32_t)Len)) { 173 Type *ITy = IntegerType::get(MI->getContext(), Len*8); // n=1 -> i8. 174 175 Value *Dest = MI->getDest(); 176 unsigned DstAddrSp = cast<PointerType>(Dest->getType())->getAddressSpace(); 177 Type *NewDstPtrTy = PointerType::get(ITy, DstAddrSp); 178 Dest = Builder->CreateBitCast(Dest, NewDstPtrTy); 179 180 // Alignment 0 is identity for alignment 1 for memset, but not store. 181 if (Alignment == 0) Alignment = 1; 182 183 // Extract the fill value and store. 184 uint64_t Fill = FillC->getZExtValue()*0x0101010101010101ULL; 185 StoreInst *S = Builder->CreateStore(ConstantInt::get(ITy, Fill), Dest, 186 MI->isVolatile()); 187 S->setAlignment(Alignment); 188 189 // Set the size of the copy to 0, it will be deleted on the next iteration. 190 MI->setLength(Constant::getNullValue(LenC->getType())); 191 return MI; 192 } 193 194 return 0; 195 } 196 197 /// visitCallInst - CallInst simplification. This mostly only handles folding 198 /// of intrinsic instructions. For normal calls, it allows visitCallSite to do 199 /// the heavy lifting. 200 /// 201 Instruction *InstCombiner::visitCallInst(CallInst &CI) { 202 if (isFreeCall(&CI, TLI)) 203 return visitFree(CI); 204 205 // If the caller function is nounwind, mark the call as nounwind, even if the 206 // callee isn't. 207 if (CI.getParent()->getParent()->doesNotThrow() && 208 !CI.doesNotThrow()) { 209 CI.setDoesNotThrow(); 210 return &CI; 211 } 212 213 IntrinsicInst *II = dyn_cast<IntrinsicInst>(&CI); 214 if (!II) return visitCallSite(&CI); 215 216 // Intrinsics cannot occur in an invoke, so handle them here instead of in 217 // visitCallSite. 218 if (MemIntrinsic *MI = dyn_cast<MemIntrinsic>(II)) { 219 bool Changed = false; 220 221 // memmove/cpy/set of zero bytes is a noop. 222 if (Constant *NumBytes = dyn_cast<Constant>(MI->getLength())) { 223 if (NumBytes->isNullValue()) 224 return EraseInstFromFunction(CI); 225 226 if (ConstantInt *CI = dyn_cast<ConstantInt>(NumBytes)) 227 if (CI->getZExtValue() == 1) { 228 // Replace the instruction with just byte operations. We would 229 // transform other cases to loads/stores, but we don't know if 230 // alignment is sufficient. 231 } 232 } 233 234 // No other transformations apply to volatile transfers. 235 if (MI->isVolatile()) 236 return 0; 237 238 // If we have a memmove and the source operation is a constant global, 239 // then the source and dest pointers can't alias, so we can change this 240 // into a call to memcpy. 241 if (MemMoveInst *MMI = dyn_cast<MemMoveInst>(MI)) { 242 if (GlobalVariable *GVSrc = dyn_cast<GlobalVariable>(MMI->getSource())) 243 if (GVSrc->isConstant()) { 244 Module *M = CI.getParent()->getParent()->getParent(); 245 Intrinsic::ID MemCpyID = Intrinsic::memcpy; 246 Type *Tys[3] = { CI.getArgOperand(0)->getType(), 247 CI.getArgOperand(1)->getType(), 248 CI.getArgOperand(2)->getType() }; 249 CI.setCalledFunction(Intrinsic::getDeclaration(M, MemCpyID, Tys)); 250 Changed = true; 251 } 252 } 253 254 if (MemTransferInst *MTI = dyn_cast<MemTransferInst>(MI)) { 255 // memmove(x,x,size) -> noop. 256 if (MTI->getSource() == MTI->getDest()) 257 return EraseInstFromFunction(CI); 258 } 259 260 // If we can determine a pointer alignment that is bigger than currently 261 // set, update the alignment. 262 if (isa<MemTransferInst>(MI)) { 263 if (Instruction *I = SimplifyMemTransfer(MI)) 264 return I; 265 } else if (MemSetInst *MSI = dyn_cast<MemSetInst>(MI)) { 266 if (Instruction *I = SimplifyMemSet(MSI)) 267 return I; 268 } 269 270 if (Changed) return II; 271 } 272 273 switch (II->getIntrinsicID()) { 274 default: break; 275 case Intrinsic::objectsize: { 276 uint64_t Size; 277 if (getObjectSize(II->getArgOperand(0), Size, TD, TLI)) 278 return ReplaceInstUsesWith(CI, ConstantInt::get(CI.getType(), Size)); 279 return 0; 280 } 281 case Intrinsic::bswap: { 282 Value *IIOperand = II->getArgOperand(0); 283 Value *X = 0; 284 285 // bswap(bswap(x)) -> x 286 if (match(IIOperand, m_BSwap(m_Value(X)))) 287 return ReplaceInstUsesWith(CI, X); 288 289 // bswap(trunc(bswap(x))) -> trunc(lshr(x, c)) 290 if (match(IIOperand, m_Trunc(m_BSwap(m_Value(X))))) { 291 unsigned C = X->getType()->getPrimitiveSizeInBits() - 292 IIOperand->getType()->getPrimitiveSizeInBits(); 293 Value *CV = ConstantInt::get(X->getType(), C); 294 Value *V = Builder->CreateLShr(X, CV); 295 return new TruncInst(V, IIOperand->getType()); 296 } 297 break; 298 } 299 300 case Intrinsic::powi: 301 if (ConstantInt *Power = dyn_cast<ConstantInt>(II->getArgOperand(1))) { 302 // powi(x, 0) -> 1.0 303 if (Power->isZero()) 304 return ReplaceInstUsesWith(CI, ConstantFP::get(CI.getType(), 1.0)); 305 // powi(x, 1) -> x 306 if (Power->isOne()) 307 return ReplaceInstUsesWith(CI, II->getArgOperand(0)); 308 // powi(x, -1) -> 1/x 309 if (Power->isAllOnesValue()) 310 return BinaryOperator::CreateFDiv(ConstantFP::get(CI.getType(), 1.0), 311 II->getArgOperand(0)); 312 } 313 break; 314 case Intrinsic::cttz: { 315 // If all bits below the first known one are known zero, 316 // this value is constant. 317 IntegerType *IT = dyn_cast<IntegerType>(II->getArgOperand(0)->getType()); 318 // FIXME: Try to simplify vectors of integers. 319 if (!IT) break; 320 uint32_t BitWidth = IT->getBitWidth(); 321 APInt KnownZero(BitWidth, 0); 322 APInt KnownOne(BitWidth, 0); 323 ComputeMaskedBits(II->getArgOperand(0), KnownZero, KnownOne); 324 unsigned TrailingZeros = KnownOne.countTrailingZeros(); 325 APInt Mask(APInt::getLowBitsSet(BitWidth, TrailingZeros)); 326 if ((Mask & KnownZero) == Mask) 327 return ReplaceInstUsesWith(CI, ConstantInt::get(IT, 328 APInt(BitWidth, TrailingZeros))); 329 330 } 331 break; 332 case Intrinsic::ctlz: { 333 // If all bits above the first known one are known zero, 334 // this value is constant. 335 IntegerType *IT = dyn_cast<IntegerType>(II->getArgOperand(0)->getType()); 336 // FIXME: Try to simplify vectors of integers. 337 if (!IT) break; 338 uint32_t BitWidth = IT->getBitWidth(); 339 APInt KnownZero(BitWidth, 0); 340 APInt KnownOne(BitWidth, 0); 341 ComputeMaskedBits(II->getArgOperand(0), KnownZero, KnownOne); 342 unsigned LeadingZeros = KnownOne.countLeadingZeros(); 343 APInt Mask(APInt::getHighBitsSet(BitWidth, LeadingZeros)); 344 if ((Mask & KnownZero) == Mask) 345 return ReplaceInstUsesWith(CI, ConstantInt::get(IT, 346 APInt(BitWidth, LeadingZeros))); 347 348 } 349 break; 350 case Intrinsic::uadd_with_overflow: { 351 Value *LHS = II->getArgOperand(0), *RHS = II->getArgOperand(1); 352 IntegerType *IT = cast<IntegerType>(II->getArgOperand(0)->getType()); 353 uint32_t BitWidth = IT->getBitWidth(); 354 APInt LHSKnownZero(BitWidth, 0); 355 APInt LHSKnownOne(BitWidth, 0); 356 ComputeMaskedBits(LHS, LHSKnownZero, LHSKnownOne); 357 bool LHSKnownNegative = LHSKnownOne[BitWidth - 1]; 358 bool LHSKnownPositive = LHSKnownZero[BitWidth - 1]; 359 360 if (LHSKnownNegative || LHSKnownPositive) { 361 APInt RHSKnownZero(BitWidth, 0); 362 APInt RHSKnownOne(BitWidth, 0); 363 ComputeMaskedBits(RHS, RHSKnownZero, RHSKnownOne); 364 bool RHSKnownNegative = RHSKnownOne[BitWidth - 1]; 365 bool RHSKnownPositive = RHSKnownZero[BitWidth - 1]; 366 if (LHSKnownNegative && RHSKnownNegative) { 367 // The sign bit is set in both cases: this MUST overflow. 368 // Create a simple add instruction, and insert it into the struct. 369 Value *Add = Builder->CreateAdd(LHS, RHS); 370 Add->takeName(&CI); 371 Constant *V[] = { 372 UndefValue::get(LHS->getType()), 373 ConstantInt::getTrue(II->getContext()) 374 }; 375 StructType *ST = cast<StructType>(II->getType()); 376 Constant *Struct = ConstantStruct::get(ST, V); 377 return InsertValueInst::Create(Struct, Add, 0); 378 } 379 380 if (LHSKnownPositive && RHSKnownPositive) { 381 // The sign bit is clear in both cases: this CANNOT overflow. 382 // Create a simple add instruction, and insert it into the struct. 383 Value *Add = Builder->CreateNUWAdd(LHS, RHS); 384 Add->takeName(&CI); 385 Constant *V[] = { 386 UndefValue::get(LHS->getType()), 387 ConstantInt::getFalse(II->getContext()) 388 }; 389 StructType *ST = cast<StructType>(II->getType()); 390 Constant *Struct = ConstantStruct::get(ST, V); 391 return InsertValueInst::Create(Struct, Add, 0); 392 } 393 } 394 } 395 // FALL THROUGH uadd into sadd 396 case Intrinsic::sadd_with_overflow: 397 // Canonicalize constants into the RHS. 398 if (isa<Constant>(II->getArgOperand(0)) && 399 !isa<Constant>(II->getArgOperand(1))) { 400 Value *LHS = II->getArgOperand(0); 401 II->setArgOperand(0, II->getArgOperand(1)); 402 II->setArgOperand(1, LHS); 403 return II; 404 } 405 406 // X + undef -> undef 407 if (isa<UndefValue>(II->getArgOperand(1))) 408 return ReplaceInstUsesWith(CI, UndefValue::get(II->getType())); 409 410 if (ConstantInt *RHS = dyn_cast<ConstantInt>(II->getArgOperand(1))) { 411 // X + 0 -> {X, false} 412 if (RHS->isZero()) { 413 Constant *V[] = { 414 UndefValue::get(II->getArgOperand(0)->getType()), 415 ConstantInt::getFalse(II->getContext()) 416 }; 417 Constant *Struct = 418 ConstantStruct::get(cast<StructType>(II->getType()), V); 419 return InsertValueInst::Create(Struct, II->getArgOperand(0), 0); 420 } 421 } 422 break; 423 case Intrinsic::usub_with_overflow: 424 case Intrinsic::ssub_with_overflow: 425 // undef - X -> undef 426 // X - undef -> undef 427 if (isa<UndefValue>(II->getArgOperand(0)) || 428 isa<UndefValue>(II->getArgOperand(1))) 429 return ReplaceInstUsesWith(CI, UndefValue::get(II->getType())); 430 431 if (ConstantInt *RHS = dyn_cast<ConstantInt>(II->getArgOperand(1))) { 432 // X - 0 -> {X, false} 433 if (RHS->isZero()) { 434 Constant *V[] = { 435 UndefValue::get(II->getArgOperand(0)->getType()), 436 ConstantInt::getFalse(II->getContext()) 437 }; 438 Constant *Struct = 439 ConstantStruct::get(cast<StructType>(II->getType()), V); 440 return InsertValueInst::Create(Struct, II->getArgOperand(0), 0); 441 } 442 } 443 break; 444 case Intrinsic::umul_with_overflow: { 445 Value *LHS = II->getArgOperand(0), *RHS = II->getArgOperand(1); 446 unsigned BitWidth = cast<IntegerType>(LHS->getType())->getBitWidth(); 447 448 APInt LHSKnownZero(BitWidth, 0); 449 APInt LHSKnownOne(BitWidth, 0); 450 ComputeMaskedBits(LHS, LHSKnownZero, LHSKnownOne); 451 APInt RHSKnownZero(BitWidth, 0); 452 APInt RHSKnownOne(BitWidth, 0); 453 ComputeMaskedBits(RHS, RHSKnownZero, RHSKnownOne); 454 455 // Get the largest possible values for each operand. 456 APInt LHSMax = ~LHSKnownZero; 457 APInt RHSMax = ~RHSKnownZero; 458 459 // If multiplying the maximum values does not overflow then we can turn 460 // this into a plain NUW mul. 461 bool Overflow; 462 LHSMax.umul_ov(RHSMax, Overflow); 463 if (!Overflow) { 464 Value *Mul = Builder->CreateNUWMul(LHS, RHS, "umul_with_overflow"); 465 Constant *V[] = { 466 UndefValue::get(LHS->getType()), 467 Builder->getFalse() 468 }; 469 Constant *Struct = ConstantStruct::get(cast<StructType>(II->getType()),V); 470 return InsertValueInst::Create(Struct, Mul, 0); 471 } 472 } // FALL THROUGH 473 case Intrinsic::smul_with_overflow: 474 // Canonicalize constants into the RHS. 475 if (isa<Constant>(II->getArgOperand(0)) && 476 !isa<Constant>(II->getArgOperand(1))) { 477 Value *LHS = II->getArgOperand(0); 478 II->setArgOperand(0, II->getArgOperand(1)); 479 II->setArgOperand(1, LHS); 480 return II; 481 } 482 483 // X * undef -> undef 484 if (isa<UndefValue>(II->getArgOperand(1))) 485 return ReplaceInstUsesWith(CI, UndefValue::get(II->getType())); 486 487 if (ConstantInt *RHSI = dyn_cast<ConstantInt>(II->getArgOperand(1))) { 488 // X*0 -> {0, false} 489 if (RHSI->isZero()) 490 return ReplaceInstUsesWith(CI, Constant::getNullValue(II->getType())); 491 492 // X * 1 -> {X, false} 493 if (RHSI->equalsInt(1)) { 494 Constant *V[] = { 495 UndefValue::get(II->getArgOperand(0)->getType()), 496 ConstantInt::getFalse(II->getContext()) 497 }; 498 Constant *Struct = 499 ConstantStruct::get(cast<StructType>(II->getType()), V); 500 return InsertValueInst::Create(Struct, II->getArgOperand(0), 0); 501 } 502 } 503 break; 504 case Intrinsic::ppc_altivec_lvx: 505 case Intrinsic::ppc_altivec_lvxl: 506 // Turn PPC lvx -> load if the pointer is known aligned. 507 if (getOrEnforceKnownAlignment(II->getArgOperand(0), 16, TD) >= 16) { 508 Value *Ptr = Builder->CreateBitCast(II->getArgOperand(0), 509 PointerType::getUnqual(II->getType())); 510 return new LoadInst(Ptr); 511 } 512 break; 513 case Intrinsic::ppc_altivec_stvx: 514 case Intrinsic::ppc_altivec_stvxl: 515 // Turn stvx -> store if the pointer is known aligned. 516 if (getOrEnforceKnownAlignment(II->getArgOperand(1), 16, TD) >= 16) { 517 Type *OpPtrTy = 518 PointerType::getUnqual(II->getArgOperand(0)->getType()); 519 Value *Ptr = Builder->CreateBitCast(II->getArgOperand(1), OpPtrTy); 520 return new StoreInst(II->getArgOperand(0), Ptr); 521 } 522 break; 523 case Intrinsic::x86_sse_storeu_ps: 524 case Intrinsic::x86_sse2_storeu_pd: 525 case Intrinsic::x86_sse2_storeu_dq: 526 // Turn X86 storeu -> store if the pointer is known aligned. 527 if (getOrEnforceKnownAlignment(II->getArgOperand(0), 16, TD) >= 16) { 528 Type *OpPtrTy = 529 PointerType::getUnqual(II->getArgOperand(1)->getType()); 530 Value *Ptr = Builder->CreateBitCast(II->getArgOperand(0), OpPtrTy); 531 return new StoreInst(II->getArgOperand(1), Ptr); 532 } 533 break; 534 535 case Intrinsic::x86_sse_cvtss2si: 536 case Intrinsic::x86_sse_cvtss2si64: 537 case Intrinsic::x86_sse_cvttss2si: 538 case Intrinsic::x86_sse_cvttss2si64: 539 case Intrinsic::x86_sse2_cvtsd2si: 540 case Intrinsic::x86_sse2_cvtsd2si64: 541 case Intrinsic::x86_sse2_cvttsd2si: 542 case Intrinsic::x86_sse2_cvttsd2si64: { 543 // These intrinsics only demand the 0th element of their input vectors. If 544 // we can simplify the input based on that, do so now. 545 unsigned VWidth = 546 cast<VectorType>(II->getArgOperand(0)->getType())->getNumElements(); 547 APInt DemandedElts(VWidth, 1); 548 APInt UndefElts(VWidth, 0); 549 if (Value *V = SimplifyDemandedVectorElts(II->getArgOperand(0), 550 DemandedElts, UndefElts)) { 551 II->setArgOperand(0, V); 552 return II; 553 } 554 break; 555 } 556 557 558 case Intrinsic::x86_sse41_pmovsxbw: 559 case Intrinsic::x86_sse41_pmovsxwd: 560 case Intrinsic::x86_sse41_pmovsxdq: 561 case Intrinsic::x86_sse41_pmovzxbw: 562 case Intrinsic::x86_sse41_pmovzxwd: 563 case Intrinsic::x86_sse41_pmovzxdq: { 564 // pmov{s|z}x ignores the upper half of their input vectors. 565 unsigned VWidth = 566 cast<VectorType>(II->getArgOperand(0)->getType())->getNumElements(); 567 unsigned LowHalfElts = VWidth / 2; 568 APInt InputDemandedElts(APInt::getBitsSet(VWidth, 0, LowHalfElts)); 569 APInt UndefElts(VWidth, 0); 570 if (Value *TmpV = SimplifyDemandedVectorElts(II->getArgOperand(0), 571 InputDemandedElts, 572 UndefElts)) { 573 II->setArgOperand(0, TmpV); 574 return II; 575 } 576 break; 577 } 578 579 case Intrinsic::ppc_altivec_vperm: 580 // Turn vperm(V1,V2,mask) -> shuffle(V1,V2,mask) if mask is a constant. 581 if (Constant *Mask = dyn_cast<Constant>(II->getArgOperand(2))) { 582 assert(Mask->getType()->getVectorNumElements() == 16 && 583 "Bad type for intrinsic!"); 584 585 // Check that all of the elements are integer constants or undefs. 586 bool AllEltsOk = true; 587 for (unsigned i = 0; i != 16; ++i) { 588 Constant *Elt = Mask->getAggregateElement(i); 589 if (Elt == 0 || 590 !(isa<ConstantInt>(Elt) || isa<UndefValue>(Elt))) { 591 AllEltsOk = false; 592 break; 593 } 594 } 595 596 if (AllEltsOk) { 597 // Cast the input vectors to byte vectors. 598 Value *Op0 = Builder->CreateBitCast(II->getArgOperand(0), 599 Mask->getType()); 600 Value *Op1 = Builder->CreateBitCast(II->getArgOperand(1), 601 Mask->getType()); 602 Value *Result = UndefValue::get(Op0->getType()); 603 604 // Only extract each element once. 605 Value *ExtractedElts[32]; 606 memset(ExtractedElts, 0, sizeof(ExtractedElts)); 607 608 for (unsigned i = 0; i != 16; ++i) { 609 if (isa<UndefValue>(Mask->getAggregateElement(i))) 610 continue; 611 unsigned Idx = 612 cast<ConstantInt>(Mask->getAggregateElement(i))->getZExtValue(); 613 Idx &= 31; // Match the hardware behavior. 614 615 if (ExtractedElts[Idx] == 0) { 616 ExtractedElts[Idx] = 617 Builder->CreateExtractElement(Idx < 16 ? Op0 : Op1, 618 Builder->getInt32(Idx&15)); 619 } 620 621 // Insert this value into the result vector. 622 Result = Builder->CreateInsertElement(Result, ExtractedElts[Idx], 623 Builder->getInt32(i)); 624 } 625 return CastInst::Create(Instruction::BitCast, Result, CI.getType()); 626 } 627 } 628 break; 629 630 case Intrinsic::arm_neon_vld1: 631 case Intrinsic::arm_neon_vld2: 632 case Intrinsic::arm_neon_vld3: 633 case Intrinsic::arm_neon_vld4: 634 case Intrinsic::arm_neon_vld2lane: 635 case Intrinsic::arm_neon_vld3lane: 636 case Intrinsic::arm_neon_vld4lane: 637 case Intrinsic::arm_neon_vst1: 638 case Intrinsic::arm_neon_vst2: 639 case Intrinsic::arm_neon_vst3: 640 case Intrinsic::arm_neon_vst4: 641 case Intrinsic::arm_neon_vst2lane: 642 case Intrinsic::arm_neon_vst3lane: 643 case Intrinsic::arm_neon_vst4lane: { 644 unsigned MemAlign = getKnownAlignment(II->getArgOperand(0), TD); 645 unsigned AlignArg = II->getNumArgOperands() - 1; 646 ConstantInt *IntrAlign = dyn_cast<ConstantInt>(II->getArgOperand(AlignArg)); 647 if (IntrAlign && IntrAlign->getZExtValue() < MemAlign) { 648 II->setArgOperand(AlignArg, 649 ConstantInt::get(Type::getInt32Ty(II->getContext()), 650 MemAlign, false)); 651 return II; 652 } 653 break; 654 } 655 656 case Intrinsic::arm_neon_vmulls: 657 case Intrinsic::arm_neon_vmullu: { 658 Value *Arg0 = II->getArgOperand(0); 659 Value *Arg1 = II->getArgOperand(1); 660 661 // Handle mul by zero first: 662 if (isa<ConstantAggregateZero>(Arg0) || isa<ConstantAggregateZero>(Arg1)) { 663 return ReplaceInstUsesWith(CI, ConstantAggregateZero::get(II->getType())); 664 } 665 666 // Check for constant LHS & RHS - in this case we just simplify. 667 bool Zext = (II->getIntrinsicID() == Intrinsic::arm_neon_vmullu); 668 VectorType *NewVT = cast<VectorType>(II->getType()); 669 unsigned NewWidth = NewVT->getElementType()->getIntegerBitWidth(); 670 if (ConstantDataVector *CV0 = dyn_cast<ConstantDataVector>(Arg0)) { 671 if (ConstantDataVector *CV1 = dyn_cast<ConstantDataVector>(Arg1)) { 672 VectorType* VT = cast<VectorType>(CV0->getType()); 673 SmallVector<Constant*, 4> NewElems; 674 for (unsigned i = 0; i < VT->getNumElements(); ++i) { 675 APInt CV0E = 676 (cast<ConstantInt>(CV0->getAggregateElement(i)))->getValue(); 677 CV0E = Zext ? CV0E.zext(NewWidth) : CV0E.sext(NewWidth); 678 APInt CV1E = 679 (cast<ConstantInt>(CV1->getAggregateElement(i)))->getValue(); 680 CV1E = Zext ? CV1E.zext(NewWidth) : CV1E.sext(NewWidth); 681 NewElems.push_back( 682 ConstantInt::get(NewVT->getElementType(), CV0E * CV1E)); 683 } 684 return ReplaceInstUsesWith(CI, ConstantVector::get(NewElems)); 685 } 686 687 // Couldn't simplify - cannonicalize constant to the RHS. 688 std::swap(Arg0, Arg1); 689 } 690 691 // Handle mul by one: 692 if (ConstantDataVector *CV1 = dyn_cast<ConstantDataVector>(Arg1)) { 693 if (ConstantInt *Splat = 694 dyn_cast_or_null<ConstantInt>(CV1->getSplatValue())) { 695 if (Splat->isOne()) { 696 if (Zext) 697 return CastInst::CreateZExtOrBitCast(Arg0, II->getType()); 698 // else 699 return CastInst::CreateSExtOrBitCast(Arg0, II->getType()); 700 } 701 } 702 } 703 704 break; 705 } 706 707 case Intrinsic::stackrestore: { 708 // If the save is right next to the restore, remove the restore. This can 709 // happen when variable allocas are DCE'd. 710 if (IntrinsicInst *SS = dyn_cast<IntrinsicInst>(II->getArgOperand(0))) { 711 if (SS->getIntrinsicID() == Intrinsic::stacksave) { 712 BasicBlock::iterator BI = SS; 713 if (&*++BI == II) 714 return EraseInstFromFunction(CI); 715 } 716 } 717 718 // Scan down this block to see if there is another stack restore in the 719 // same block without an intervening call/alloca. 720 BasicBlock::iterator BI = II; 721 TerminatorInst *TI = II->getParent()->getTerminator(); 722 bool CannotRemove = false; 723 for (++BI; &*BI != TI; ++BI) { 724 if (isa<AllocaInst>(BI)) { 725 CannotRemove = true; 726 break; 727 } 728 if (CallInst *BCI = dyn_cast<CallInst>(BI)) { 729 if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(BCI)) { 730 // If there is a stackrestore below this one, remove this one. 731 if (II->getIntrinsicID() == Intrinsic::stackrestore) 732 return EraseInstFromFunction(CI); 733 // Otherwise, ignore the intrinsic. 734 } else { 735 // If we found a non-intrinsic call, we can't remove the stack 736 // restore. 737 CannotRemove = true; 738 break; 739 } 740 } 741 } 742 743 // If the stack restore is in a return, resume, or unwind block and if there 744 // are no allocas or calls between the restore and the return, nuke the 745 // restore. 746 if (!CannotRemove && (isa<ReturnInst>(TI) || isa<ResumeInst>(TI))) 747 return EraseInstFromFunction(CI); 748 break; 749 } 750 } 751 752 return visitCallSite(II); 753 } 754 755 // InvokeInst simplification 756 // 757 Instruction *InstCombiner::visitInvokeInst(InvokeInst &II) { 758 return visitCallSite(&II); 759 } 760 761 /// isSafeToEliminateVarargsCast - If this cast does not affect the value 762 /// passed through the varargs area, we can eliminate the use of the cast. 763 static bool isSafeToEliminateVarargsCast(const CallSite CS, 764 const CastInst * const CI, 765 const DataLayout * const TD, 766 const int ix) { 767 if (!CI->isLosslessCast()) 768 return false; 769 770 // The size of ByVal arguments is derived from the type, so we 771 // can't change to a type with a different size. If the size were 772 // passed explicitly we could avoid this check. 773 if (!CS.isByValArgument(ix)) 774 return true; 775 776 Type* SrcTy = 777 cast<PointerType>(CI->getOperand(0)->getType())->getElementType(); 778 Type* DstTy = cast<PointerType>(CI->getType())->getElementType(); 779 if (!SrcTy->isSized() || !DstTy->isSized()) 780 return false; 781 if (!TD || TD->getTypeAllocSize(SrcTy) != TD->getTypeAllocSize(DstTy)) 782 return false; 783 return true; 784 } 785 786 // Try to fold some different type of calls here. 787 // Currently we're only working with the checking functions, memcpy_chk, 788 // mempcpy_chk, memmove_chk, memset_chk, strcpy_chk, stpcpy_chk, strncpy_chk, 789 // strcat_chk and strncat_chk. 790 Instruction *InstCombiner::tryOptimizeCall(CallInst *CI, const DataLayout *TD) { 791 if (CI->getCalledFunction() == 0) return 0; 792 793 if (Value *With = Simplifier->optimizeCall(CI)) { 794 ++NumSimplified; 795 return CI->use_empty() ? CI : ReplaceInstUsesWith(*CI, With); 796 } 797 798 return 0; 799 } 800 801 static IntrinsicInst *FindInitTrampolineFromAlloca(Value *TrampMem) { 802 // Strip off at most one level of pointer casts, looking for an alloca. This 803 // is good enough in practice and simpler than handling any number of casts. 804 Value *Underlying = TrampMem->stripPointerCasts(); 805 if (Underlying != TrampMem && 806 (!Underlying->hasOneUse() || *Underlying->use_begin() != TrampMem)) 807 return 0; 808 if (!isa<AllocaInst>(Underlying)) 809 return 0; 810 811 IntrinsicInst *InitTrampoline = 0; 812 for (Value::use_iterator I = TrampMem->use_begin(), E = TrampMem->use_end(); 813 I != E; I++) { 814 IntrinsicInst *II = dyn_cast<IntrinsicInst>(*I); 815 if (!II) 816 return 0; 817 if (II->getIntrinsicID() == Intrinsic::init_trampoline) { 818 if (InitTrampoline) 819 // More than one init_trampoline writes to this value. Give up. 820 return 0; 821 InitTrampoline = II; 822 continue; 823 } 824 if (II->getIntrinsicID() == Intrinsic::adjust_trampoline) 825 // Allow any number of calls to adjust.trampoline. 826 continue; 827 return 0; 828 } 829 830 // No call to init.trampoline found. 831 if (!InitTrampoline) 832 return 0; 833 834 // Check that the alloca is being used in the expected way. 835 if (InitTrampoline->getOperand(0) != TrampMem) 836 return 0; 837 838 return InitTrampoline; 839 } 840 841 static IntrinsicInst *FindInitTrampolineFromBB(IntrinsicInst *AdjustTramp, 842 Value *TrampMem) { 843 // Visit all the previous instructions in the basic block, and try to find a 844 // init.trampoline which has a direct path to the adjust.trampoline. 845 for (BasicBlock::iterator I = AdjustTramp, 846 E = AdjustTramp->getParent()->begin(); I != E; ) { 847 Instruction *Inst = --I; 848 if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(I)) 849 if (II->getIntrinsicID() == Intrinsic::init_trampoline && 850 II->getOperand(0) == TrampMem) 851 return II; 852 if (Inst->mayWriteToMemory()) 853 return 0; 854 } 855 return 0; 856 } 857 858 // Given a call to llvm.adjust.trampoline, find and return the corresponding 859 // call to llvm.init.trampoline if the call to the trampoline can be optimized 860 // to a direct call to a function. Otherwise return NULL. 861 // 862 static IntrinsicInst *FindInitTrampoline(Value *Callee) { 863 Callee = Callee->stripPointerCasts(); 864 IntrinsicInst *AdjustTramp = dyn_cast<IntrinsicInst>(Callee); 865 if (!AdjustTramp || 866 AdjustTramp->getIntrinsicID() != Intrinsic::adjust_trampoline) 867 return 0; 868 869 Value *TrampMem = AdjustTramp->getOperand(0); 870 871 if (IntrinsicInst *IT = FindInitTrampolineFromAlloca(TrampMem)) 872 return IT; 873 if (IntrinsicInst *IT = FindInitTrampolineFromBB(AdjustTramp, TrampMem)) 874 return IT; 875 return 0; 876 } 877 878 // visitCallSite - Improvements for call and invoke instructions. 879 // 880 Instruction *InstCombiner::visitCallSite(CallSite CS) { 881 if (isAllocLikeFn(CS.getInstruction(), TLI)) 882 return visitAllocSite(*CS.getInstruction()); 883 884 bool Changed = false; 885 886 // If the callee is a pointer to a function, attempt to move any casts to the 887 // arguments of the call/invoke. 888 Value *Callee = CS.getCalledValue(); 889 if (!isa<Function>(Callee) && transformConstExprCastCall(CS)) 890 return 0; 891 892 if (Function *CalleeF = dyn_cast<Function>(Callee)) 893 // If the call and callee calling conventions don't match, this call must 894 // be unreachable, as the call is undefined. 895 if (CalleeF->getCallingConv() != CS.getCallingConv() && 896 // Only do this for calls to a function with a body. A prototype may 897 // not actually end up matching the implementation's calling conv for a 898 // variety of reasons (e.g. it may be written in assembly). 899 !CalleeF->isDeclaration()) { 900 Instruction *OldCall = CS.getInstruction(); 901 new StoreInst(ConstantInt::getTrue(Callee->getContext()), 902 UndefValue::get(Type::getInt1PtrTy(Callee->getContext())), 903 OldCall); 904 // If OldCall does not return void then replaceAllUsesWith undef. 905 // This allows ValueHandlers and custom metadata to adjust itself. 906 if (!OldCall->getType()->isVoidTy()) 907 ReplaceInstUsesWith(*OldCall, UndefValue::get(OldCall->getType())); 908 if (isa<CallInst>(OldCall)) 909 return EraseInstFromFunction(*OldCall); 910 911 // We cannot remove an invoke, because it would change the CFG, just 912 // change the callee to a null pointer. 913 cast<InvokeInst>(OldCall)->setCalledFunction( 914 Constant::getNullValue(CalleeF->getType())); 915 return 0; 916 } 917 918 if (isa<ConstantPointerNull>(Callee) || isa<UndefValue>(Callee)) { 919 // If CS does not return void then replaceAllUsesWith undef. 920 // This allows ValueHandlers and custom metadata to adjust itself. 921 if (!CS.getInstruction()->getType()->isVoidTy()) 922 ReplaceInstUsesWith(*CS.getInstruction(), 923 UndefValue::get(CS.getInstruction()->getType())); 924 925 if (isa<InvokeInst>(CS.getInstruction())) { 926 // Can't remove an invoke because we cannot change the CFG. 927 return 0; 928 } 929 930 // This instruction is not reachable, just remove it. We insert a store to 931 // undef so that we know that this code is not reachable, despite the fact 932 // that we can't modify the CFG here. 933 new StoreInst(ConstantInt::getTrue(Callee->getContext()), 934 UndefValue::get(Type::getInt1PtrTy(Callee->getContext())), 935 CS.getInstruction()); 936 937 return EraseInstFromFunction(*CS.getInstruction()); 938 } 939 940 if (IntrinsicInst *II = FindInitTrampoline(Callee)) 941 return transformCallThroughTrampoline(CS, II); 942 943 PointerType *PTy = cast<PointerType>(Callee->getType()); 944 FunctionType *FTy = cast<FunctionType>(PTy->getElementType()); 945 if (FTy->isVarArg()) { 946 int ix = FTy->getNumParams(); 947 // See if we can optimize any arguments passed through the varargs area of 948 // the call. 949 for (CallSite::arg_iterator I = CS.arg_begin() + FTy->getNumParams(), 950 E = CS.arg_end(); I != E; ++I, ++ix) { 951 CastInst *CI = dyn_cast<CastInst>(*I); 952 if (CI && isSafeToEliminateVarargsCast(CS, CI, TD, ix)) { 953 *I = CI->getOperand(0); 954 Changed = true; 955 } 956 } 957 } 958 959 if (isa<InlineAsm>(Callee) && !CS.doesNotThrow()) { 960 // Inline asm calls cannot throw - mark them 'nounwind'. 961 CS.setDoesNotThrow(); 962 Changed = true; 963 } 964 965 // Try to optimize the call if possible, we require DataLayout for most of 966 // this. None of these calls are seen as possibly dead so go ahead and 967 // delete the instruction now. 968 if (CallInst *CI = dyn_cast<CallInst>(CS.getInstruction())) { 969 Instruction *I = tryOptimizeCall(CI, TD); 970 // If we changed something return the result, etc. Otherwise let 971 // the fallthrough check. 972 if (I) return EraseInstFromFunction(*I); 973 } 974 975 return Changed ? CS.getInstruction() : 0; 976 } 977 978 // transformConstExprCastCall - If the callee is a constexpr cast of a function, 979 // attempt to move the cast to the arguments of the call/invoke. 980 // 981 bool InstCombiner::transformConstExprCastCall(CallSite CS) { 982 Function *Callee = 983 dyn_cast<Function>(CS.getCalledValue()->stripPointerCasts()); 984 if (Callee == 0) 985 return false; 986 Instruction *Caller = CS.getInstruction(); 987 const AttributeSet &CallerPAL = CS.getAttributes(); 988 989 // Okay, this is a cast from a function to a different type. Unless doing so 990 // would cause a type conversion of one of our arguments, change this call to 991 // be a direct call with arguments casted to the appropriate types. 992 // 993 FunctionType *FT = Callee->getFunctionType(); 994 Type *OldRetTy = Caller->getType(); 995 Type *NewRetTy = FT->getReturnType(); 996 997 if (NewRetTy->isStructTy()) 998 return false; // TODO: Handle multiple return values. 999 1000 // Check to see if we are changing the return type... 1001 if (OldRetTy != NewRetTy) { 1002 if (Callee->isDeclaration() && 1003 // Conversion is ok if changing from one pointer type to another or from 1004 // a pointer to an integer of the same size. 1005 !((OldRetTy->isPointerTy() || !TD || 1006 OldRetTy == TD->getIntPtrType(Caller->getContext())) && 1007 (NewRetTy->isPointerTy() || !TD || 1008 NewRetTy == TD->getIntPtrType(Caller->getContext())))) 1009 return false; // Cannot transform this return value. 1010 1011 if (!Caller->use_empty() && 1012 // void -> non-void is handled specially 1013 !NewRetTy->isVoidTy() && 1014 !CastInst::isBitCastable(NewRetTy, OldRetTy)) 1015 return false; // Cannot transform this return value. 1016 1017 if (!CallerPAL.isEmpty() && !Caller->use_empty()) { 1018 AttrBuilder RAttrs(CallerPAL, AttributeSet::ReturnIndex); 1019 if (RAttrs. 1020 hasAttributes(AttributeFuncs:: 1021 typeIncompatible(NewRetTy, AttributeSet::ReturnIndex), 1022 AttributeSet::ReturnIndex)) 1023 return false; // Attribute not compatible with transformed value. 1024 } 1025 1026 // If the callsite is an invoke instruction, and the return value is used by 1027 // a PHI node in a successor, we cannot change the return type of the call 1028 // because there is no place to put the cast instruction (without breaking 1029 // the critical edge). Bail out in this case. 1030 if (!Caller->use_empty()) 1031 if (InvokeInst *II = dyn_cast<InvokeInst>(Caller)) 1032 for (Value::use_iterator UI = II->use_begin(), E = II->use_end(); 1033 UI != E; ++UI) 1034 if (PHINode *PN = dyn_cast<PHINode>(*UI)) 1035 if (PN->getParent() == II->getNormalDest() || 1036 PN->getParent() == II->getUnwindDest()) 1037 return false; 1038 } 1039 1040 unsigned NumActualArgs = CS.arg_size(); 1041 unsigned NumCommonArgs = std::min(FT->getNumParams(), NumActualArgs); 1042 1043 CallSite::arg_iterator AI = CS.arg_begin(); 1044 for (unsigned i = 0, e = NumCommonArgs; i != e; ++i, ++AI) { 1045 Type *ParamTy = FT->getParamType(i); 1046 Type *ActTy = (*AI)->getType(); 1047 1048 if (!CastInst::isBitCastable(ActTy, ParamTy)) { 1049 return false; // Cannot transform this parameter value. 1050 } 1051 1052 if (AttrBuilder(CallerPAL.getParamAttributes(i + 1), i + 1). 1053 hasAttributes(AttributeFuncs:: 1054 typeIncompatible(ParamTy, i + 1), i + 1)) 1055 return false; // Attribute not compatible with transformed value. 1056 1057 // If the parameter is passed as a byval argument, then we have to have a 1058 // sized type and the sized type has to have the same size as the old type. 1059 if (ParamTy != ActTy && 1060 CallerPAL.getParamAttributes(i + 1).hasAttribute(i + 1, 1061 Attribute::ByVal)) { 1062 PointerType *ParamPTy = dyn_cast<PointerType>(ParamTy); 1063 if (ParamPTy == 0 || !ParamPTy->getElementType()->isSized() || TD == 0) 1064 return false; 1065 1066 Type *CurElTy = cast<PointerType>(ActTy)->getElementType(); 1067 if (TD->getTypeAllocSize(CurElTy) != 1068 TD->getTypeAllocSize(ParamPTy->getElementType())) 1069 return false; 1070 } 1071 1072 // Converting from one pointer type to another or between a pointer and an 1073 // integer of the same size is safe even if we do not have a body. 1074 bool isConvertible = ActTy == ParamTy || 1075 (TD && ((ParamTy->isPointerTy() || 1076 ParamTy == TD->getIntPtrType(Caller->getContext())) && 1077 (ActTy->isPointerTy() || 1078 ActTy == TD->getIntPtrType(Caller->getContext())))); 1079 if (Callee->isDeclaration() && !isConvertible) 1080 return false; 1081 } 1082 1083 if (Callee->isDeclaration()) { 1084 // Do not delete arguments unless we have a function body. 1085 if (FT->getNumParams() < NumActualArgs && !FT->isVarArg()) 1086 return false; 1087 1088 // If the callee is just a declaration, don't change the varargsness of the 1089 // call. We don't want to introduce a varargs call where one doesn't 1090 // already exist. 1091 PointerType *APTy = cast<PointerType>(CS.getCalledValue()->getType()); 1092 if (FT->isVarArg()!=cast<FunctionType>(APTy->getElementType())->isVarArg()) 1093 return false; 1094 1095 // If both the callee and the cast type are varargs, we still have to make 1096 // sure the number of fixed parameters are the same or we have the same 1097 // ABI issues as if we introduce a varargs call. 1098 if (FT->isVarArg() && 1099 cast<FunctionType>(APTy->getElementType())->isVarArg() && 1100 FT->getNumParams() != 1101 cast<FunctionType>(APTy->getElementType())->getNumParams()) 1102 return false; 1103 } 1104 1105 if (FT->getNumParams() < NumActualArgs && FT->isVarArg() && 1106 !CallerPAL.isEmpty()) 1107 // In this case we have more arguments than the new function type, but we 1108 // won't be dropping them. Check that these extra arguments have attributes 1109 // that are compatible with being a vararg call argument. 1110 for (unsigned i = CallerPAL.getNumSlots(); i; --i) { 1111 unsigned Index = CallerPAL.getSlotIndex(i - 1); 1112 if (Index <= FT->getNumParams()) 1113 break; 1114 1115 // Check if it has an attribute that's incompatible with varargs. 1116 AttributeSet PAttrs = CallerPAL.getSlotAttributes(i - 1); 1117 if (PAttrs.hasAttribute(Index, Attribute::StructRet)) 1118 return false; 1119 } 1120 1121 1122 // Okay, we decided that this is a safe thing to do: go ahead and start 1123 // inserting cast instructions as necessary. 1124 std::vector<Value*> Args; 1125 Args.reserve(NumActualArgs); 1126 SmallVector<AttributeSet, 8> attrVec; 1127 attrVec.reserve(NumCommonArgs); 1128 1129 // Get any return attributes. 1130 AttrBuilder RAttrs(CallerPAL, AttributeSet::ReturnIndex); 1131 1132 // If the return value is not being used, the type may not be compatible 1133 // with the existing attributes. Wipe out any problematic attributes. 1134 RAttrs. 1135 removeAttributes(AttributeFuncs:: 1136 typeIncompatible(NewRetTy, AttributeSet::ReturnIndex), 1137 AttributeSet::ReturnIndex); 1138 1139 // Add the new return attributes. 1140 if (RAttrs.hasAttributes()) 1141 attrVec.push_back(AttributeSet::get(Caller->getContext(), 1142 AttributeSet::ReturnIndex, RAttrs)); 1143 1144 AI = CS.arg_begin(); 1145 for (unsigned i = 0; i != NumCommonArgs; ++i, ++AI) { 1146 Type *ParamTy = FT->getParamType(i); 1147 1148 if ((*AI)->getType() == ParamTy) { 1149 Args.push_back(*AI); 1150 } else { 1151 Args.push_back(Builder->CreateBitCast(*AI, ParamTy)); 1152 } 1153 1154 // Add any parameter attributes. 1155 AttrBuilder PAttrs(CallerPAL.getParamAttributes(i + 1), i + 1); 1156 if (PAttrs.hasAttributes()) 1157 attrVec.push_back(AttributeSet::get(Caller->getContext(), i + 1, 1158 PAttrs)); 1159 } 1160 1161 // If the function takes more arguments than the call was taking, add them 1162 // now. 1163 for (unsigned i = NumCommonArgs; i != FT->getNumParams(); ++i) 1164 Args.push_back(Constant::getNullValue(FT->getParamType(i))); 1165 1166 // If we are removing arguments to the function, emit an obnoxious warning. 1167 if (FT->getNumParams() < NumActualArgs) { 1168 // TODO: if (!FT->isVarArg()) this call may be unreachable. PR14722 1169 if (FT->isVarArg()) { 1170 // Add all of the arguments in their promoted form to the arg list. 1171 for (unsigned i = FT->getNumParams(); i != NumActualArgs; ++i, ++AI) { 1172 Type *PTy = getPromotedType((*AI)->getType()); 1173 if (PTy != (*AI)->getType()) { 1174 // Must promote to pass through va_arg area! 1175 Instruction::CastOps opcode = 1176 CastInst::getCastOpcode(*AI, false, PTy, false); 1177 Args.push_back(Builder->CreateCast(opcode, *AI, PTy)); 1178 } else { 1179 Args.push_back(*AI); 1180 } 1181 1182 // Add any parameter attributes. 1183 AttrBuilder PAttrs(CallerPAL.getParamAttributes(i + 1), i + 1); 1184 if (PAttrs.hasAttributes()) 1185 attrVec.push_back(AttributeSet::get(FT->getContext(), i + 1, 1186 PAttrs)); 1187 } 1188 } 1189 } 1190 1191 AttributeSet FnAttrs = CallerPAL.getFnAttributes(); 1192 if (CallerPAL.hasAttributes(AttributeSet::FunctionIndex)) 1193 attrVec.push_back(AttributeSet::get(Callee->getContext(), FnAttrs)); 1194 1195 if (NewRetTy->isVoidTy()) 1196 Caller->setName(""); // Void type should not have a name. 1197 1198 const AttributeSet &NewCallerPAL = AttributeSet::get(Callee->getContext(), 1199 attrVec); 1200 1201 Instruction *NC; 1202 if (InvokeInst *II = dyn_cast<InvokeInst>(Caller)) { 1203 NC = Builder->CreateInvoke(Callee, II->getNormalDest(), 1204 II->getUnwindDest(), Args); 1205 NC->takeName(II); 1206 cast<InvokeInst>(NC)->setCallingConv(II->getCallingConv()); 1207 cast<InvokeInst>(NC)->setAttributes(NewCallerPAL); 1208 } else { 1209 CallInst *CI = cast<CallInst>(Caller); 1210 NC = Builder->CreateCall(Callee, Args); 1211 NC->takeName(CI); 1212 if (CI->isTailCall()) 1213 cast<CallInst>(NC)->setTailCall(); 1214 cast<CallInst>(NC)->setCallingConv(CI->getCallingConv()); 1215 cast<CallInst>(NC)->setAttributes(NewCallerPAL); 1216 } 1217 1218 // Insert a cast of the return type as necessary. 1219 Value *NV = NC; 1220 if (OldRetTy != NV->getType() && !Caller->use_empty()) { 1221 if (!NV->getType()->isVoidTy()) { 1222 NV = NC = CastInst::Create(CastInst::BitCast, NC, OldRetTy); 1223 NC->setDebugLoc(Caller->getDebugLoc()); 1224 1225 // If this is an invoke instruction, we should insert it after the first 1226 // non-phi, instruction in the normal successor block. 1227 if (InvokeInst *II = dyn_cast<InvokeInst>(Caller)) { 1228 BasicBlock::iterator I = II->getNormalDest()->getFirstInsertionPt(); 1229 InsertNewInstBefore(NC, *I); 1230 } else { 1231 // Otherwise, it's a call, just insert cast right after the call. 1232 InsertNewInstBefore(NC, *Caller); 1233 } 1234 Worklist.AddUsersToWorkList(*Caller); 1235 } else { 1236 NV = UndefValue::get(Caller->getType()); 1237 } 1238 } 1239 1240 if (!Caller->use_empty()) 1241 ReplaceInstUsesWith(*Caller, NV); 1242 1243 EraseInstFromFunction(*Caller); 1244 return true; 1245 } 1246 1247 // transformCallThroughTrampoline - Turn a call to a function created by 1248 // init_trampoline / adjust_trampoline intrinsic pair into a direct call to the 1249 // underlying function. 1250 // 1251 Instruction * 1252 InstCombiner::transformCallThroughTrampoline(CallSite CS, 1253 IntrinsicInst *Tramp) { 1254 Value *Callee = CS.getCalledValue(); 1255 PointerType *PTy = cast<PointerType>(Callee->getType()); 1256 FunctionType *FTy = cast<FunctionType>(PTy->getElementType()); 1257 const AttributeSet &Attrs = CS.getAttributes(); 1258 1259 // If the call already has the 'nest' attribute somewhere then give up - 1260 // otherwise 'nest' would occur twice after splicing in the chain. 1261 if (Attrs.hasAttrSomewhere(Attribute::Nest)) 1262 return 0; 1263 1264 assert(Tramp && 1265 "transformCallThroughTrampoline called with incorrect CallSite."); 1266 1267 Function *NestF =cast<Function>(Tramp->getArgOperand(1)->stripPointerCasts()); 1268 PointerType *NestFPTy = cast<PointerType>(NestF->getType()); 1269 FunctionType *NestFTy = cast<FunctionType>(NestFPTy->getElementType()); 1270 1271 const AttributeSet &NestAttrs = NestF->getAttributes(); 1272 if (!NestAttrs.isEmpty()) { 1273 unsigned NestIdx = 1; 1274 Type *NestTy = 0; 1275 AttributeSet NestAttr; 1276 1277 // Look for a parameter marked with the 'nest' attribute. 1278 for (FunctionType::param_iterator I = NestFTy->param_begin(), 1279 E = NestFTy->param_end(); I != E; ++NestIdx, ++I) 1280 if (NestAttrs.hasAttribute(NestIdx, Attribute::Nest)) { 1281 // Record the parameter type and any other attributes. 1282 NestTy = *I; 1283 NestAttr = NestAttrs.getParamAttributes(NestIdx); 1284 break; 1285 } 1286 1287 if (NestTy) { 1288 Instruction *Caller = CS.getInstruction(); 1289 std::vector<Value*> NewArgs; 1290 NewArgs.reserve(CS.arg_size() + 1); 1291 1292 SmallVector<AttributeSet, 8> NewAttrs; 1293 NewAttrs.reserve(Attrs.getNumSlots() + 1); 1294 1295 // Insert the nest argument into the call argument list, which may 1296 // mean appending it. Likewise for attributes. 1297 1298 // Add any result attributes. 1299 if (Attrs.hasAttributes(AttributeSet::ReturnIndex)) 1300 NewAttrs.push_back(AttributeSet::get(Caller->getContext(), 1301 Attrs.getRetAttributes())); 1302 1303 { 1304 unsigned Idx = 1; 1305 CallSite::arg_iterator I = CS.arg_begin(), E = CS.arg_end(); 1306 do { 1307 if (Idx == NestIdx) { 1308 // Add the chain argument and attributes. 1309 Value *NestVal = Tramp->getArgOperand(2); 1310 if (NestVal->getType() != NestTy) 1311 NestVal = Builder->CreateBitCast(NestVal, NestTy, "nest"); 1312 NewArgs.push_back(NestVal); 1313 NewAttrs.push_back(AttributeSet::get(Caller->getContext(), 1314 NestAttr)); 1315 } 1316 1317 if (I == E) 1318 break; 1319 1320 // Add the original argument and attributes. 1321 NewArgs.push_back(*I); 1322 AttributeSet Attr = Attrs.getParamAttributes(Idx); 1323 if (Attr.hasAttributes(Idx)) { 1324 AttrBuilder B(Attr, Idx); 1325 NewAttrs.push_back(AttributeSet::get(Caller->getContext(), 1326 Idx + (Idx >= NestIdx), B)); 1327 } 1328 1329 ++Idx, ++I; 1330 } while (1); 1331 } 1332 1333 // Add any function attributes. 1334 if (Attrs.hasAttributes(AttributeSet::FunctionIndex)) 1335 NewAttrs.push_back(AttributeSet::get(FTy->getContext(), 1336 Attrs.getFnAttributes())); 1337 1338 // The trampoline may have been bitcast to a bogus type (FTy). 1339 // Handle this by synthesizing a new function type, equal to FTy 1340 // with the chain parameter inserted. 1341 1342 std::vector<Type*> NewTypes; 1343 NewTypes.reserve(FTy->getNumParams()+1); 1344 1345 // Insert the chain's type into the list of parameter types, which may 1346 // mean appending it. 1347 { 1348 unsigned Idx = 1; 1349 FunctionType::param_iterator I = FTy->param_begin(), 1350 E = FTy->param_end(); 1351 1352 do { 1353 if (Idx == NestIdx) 1354 // Add the chain's type. 1355 NewTypes.push_back(NestTy); 1356 1357 if (I == E) 1358 break; 1359 1360 // Add the original type. 1361 NewTypes.push_back(*I); 1362 1363 ++Idx, ++I; 1364 } while (1); 1365 } 1366 1367 // Replace the trampoline call with a direct call. Let the generic 1368 // code sort out any function type mismatches. 1369 FunctionType *NewFTy = FunctionType::get(FTy->getReturnType(), NewTypes, 1370 FTy->isVarArg()); 1371 Constant *NewCallee = 1372 NestF->getType() == PointerType::getUnqual(NewFTy) ? 1373 NestF : ConstantExpr::getBitCast(NestF, 1374 PointerType::getUnqual(NewFTy)); 1375 const AttributeSet &NewPAL = 1376 AttributeSet::get(FTy->getContext(), NewAttrs); 1377 1378 Instruction *NewCaller; 1379 if (InvokeInst *II = dyn_cast<InvokeInst>(Caller)) { 1380 NewCaller = InvokeInst::Create(NewCallee, 1381 II->getNormalDest(), II->getUnwindDest(), 1382 NewArgs); 1383 cast<InvokeInst>(NewCaller)->setCallingConv(II->getCallingConv()); 1384 cast<InvokeInst>(NewCaller)->setAttributes(NewPAL); 1385 } else { 1386 NewCaller = CallInst::Create(NewCallee, NewArgs); 1387 if (cast<CallInst>(Caller)->isTailCall()) 1388 cast<CallInst>(NewCaller)->setTailCall(); 1389 cast<CallInst>(NewCaller)-> 1390 setCallingConv(cast<CallInst>(Caller)->getCallingConv()); 1391 cast<CallInst>(NewCaller)->setAttributes(NewPAL); 1392 } 1393 1394 return NewCaller; 1395 } 1396 } 1397 1398 // Replace the trampoline call with a direct call. Since there is no 'nest' 1399 // parameter, there is no need to adjust the argument list. Let the generic 1400 // code sort out any function type mismatches. 1401 Constant *NewCallee = 1402 NestF->getType() == PTy ? NestF : 1403 ConstantExpr::getBitCast(NestF, PTy); 1404 CS.setCalledFunction(NewCallee); 1405 return CS.getInstruction(); 1406 } 1407
