InstCombineCalls.cpp revision 1df9859c40492511b8aa4321eb76496005d3b75b
15c02ac1a9c1b504631c0a3d2b6e737b5d738bae1Bo Liu//===- InstCombineCalls.cpp -----------------------------------------------===// 25821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 35821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// The LLVM Compiler Infrastructure 45821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 55821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// This file is distributed under the University of Illinois Open Source 65821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// License. See LICENSE.TXT for details. 75821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 85821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)//===----------------------------------------------------------------------===// 91320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci// 101320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci// This file implements the visitCall and visitInvoke functions. 115821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 125821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)//===----------------------------------------------------------------------===// 135821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 145821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "InstCombine.h" 155821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "llvm/IntrinsicInst.h" 165821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "llvm/Support/CallSite.h" 175821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "llvm/Target/TargetData.h" 185821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "llvm/Analysis/MemoryBuiltins.h" 195821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)using namespace llvm; 205821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 2103b57e008b61dfcb1fbad3aea950ae0e001748b0Torne (Richard Coles)/// getPromotedType - Return the specified type promoted as it would be to pass 2203b57e008b61dfcb1fbad3aea950ae0e001748b0Torne (Richard Coles)/// though a va_arg area. 2303b57e008b61dfcb1fbad3aea950ae0e001748b0Torne (Richard Coles)static const Type *getPromotedType(const Type *Ty) { 2403b57e008b61dfcb1fbad3aea950ae0e001748b0Torne (Richard Coles) if (const IntegerType* ITy = dyn_cast<IntegerType>(Ty)) { 2503b57e008b61dfcb1fbad3aea950ae0e001748b0Torne (Richard Coles) if (ITy->getBitWidth() < 32) 2603b57e008b61dfcb1fbad3aea950ae0e001748b0Torne (Richard Coles) return Type::getInt32Ty(Ty->getContext()); 275c02ac1a9c1b504631c0a3d2b6e737b5d738bae1Bo Liu } 285c02ac1a9c1b504631c0a3d2b6e737b5d738bae1Bo Liu return Ty; 295821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 302a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 315821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)/// EnforceKnownAlignment - If the specified pointer points to an object that 325821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)/// we control, modify the object's alignment to PrefAlign. This isn't 335821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)/// often possible though. If alignment is important, a more reliable approach 342a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)/// is to simply align all global variables and allocation instructions to 352a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)/// their preferred alignment from the beginning. 362a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)/// 372a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)static unsigned EnforceKnownAlignment(Value *V, 382a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) unsigned Align, unsigned PrefAlign) { 395821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 402a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) User *U = dyn_cast<User>(V); 412a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) if (!U) return Align; 425821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 435821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) switch (Operator::getOpcode(U)) { 442a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) default: break; 452a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) case Instruction::BitCast: 462a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) return EnforceKnownAlignment(U->getOperand(0), Align, PrefAlign); 475821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) case Instruction::GetElementPtr: { 485821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // If all indexes are zero, it is just the alignment of the base pointer. 495821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) bool AllZeroOperands = true; 505821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) for (User::op_iterator i = U->op_begin() + 1, e = U->op_end(); i != e; ++i) 515821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (!isa<Constant>(*i) || 525821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) !cast<Constant>(*i)->isNullValue()) { 535821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) AllZeroOperands = false; 545821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) break; 555821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 565821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 575821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (AllZeroOperands) { 582a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) // Treat this like a bitcast. 595821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return EnforceKnownAlignment(U->getOperand(0), Align, PrefAlign); 605821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 615821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) break; 625821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 635821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 645821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 655821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (GlobalValue *GV = dyn_cast<GlobalValue>(V)) { 665821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // If there is a large requested alignment and we can, bump up the alignment 675821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // of the global. 685821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (!GV->isDeclaration()) { 695821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (GV->getAlignment() >= PrefAlign) 705821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) Align = GV->getAlignment(); 712a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) else { 725821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) GV->setAlignment(PrefAlign); 735821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) Align = PrefAlign; 745821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 755821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 765821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } else if (AllocaInst *AI = dyn_cast<AllocaInst>(V)) { 775821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // If there is a requested alignment and if this is an alloca, round up. 785821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (AI->getAlignment() >= PrefAlign) 795821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) Align = AI->getAlignment(); 805821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) else { 812a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) AI->setAlignment(PrefAlign); 825821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) Align = PrefAlign; 835821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 845821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 855821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 865821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return Align; 875821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 885821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 895821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)/// GetOrEnforceKnownAlignment - If the specified pointer has an alignment that 905821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)/// we can determine, return it, otherwise return 0. If PrefAlign is specified, 915821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)/// and it is more than the alignment of the ultimate object, see if we can 925821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)/// increase the alignment of the ultimate object, making this check succeed. 935821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)unsigned InstCombiner::GetOrEnforceKnownAlignment(Value *V, 945821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) unsigned PrefAlign) { 955821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) unsigned BitWidth = TD ? TD->getTypeSizeInBits(V->getType()) : 965821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) sizeof(PrefAlign) * CHAR_BIT; 975821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) APInt Mask = APInt::getAllOnesValue(BitWidth); 985821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) APInt KnownZero(BitWidth, 0), KnownOne(BitWidth, 0); 995821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) ComputeMaskedBits(V, Mask, KnownZero, KnownOne); 1005821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) unsigned TrailZ = KnownZero.countTrailingOnes(); 1012a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) unsigned Align = 1u << std::min(BitWidth - 1, TrailZ); 1025821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1035821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (PrefAlign > Align) 1042a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) Align = EnforceKnownAlignment(V, Align, PrefAlign); 1056d86b77056ed63eb6871182f42a9fd5f07550f90Torne (Richard Coles) 10603b57e008b61dfcb1fbad3aea950ae0e001748b0Torne (Richard Coles) // We don't need to make any adjustment. 107a3f6a49ab37290eeeb8db0f41ec0f1cb74a68be7Torne (Richard Coles) return Align; 1082a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)} 1096d86b77056ed63eb6871182f42a9fd5f07550f90Torne (Richard Coles) 1106d86b77056ed63eb6871182f42a9fd5f07550f90Torne (Richard Coles)Instruction *InstCombiner::SimplifyMemTransfer(MemIntrinsic *MI) { 1115821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) unsigned DstAlign = GetOrEnforceKnownAlignment(MI->getOperand(1)); 1125821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) unsigned SrcAlign = GetOrEnforceKnownAlignment(MI->getOperand(2)); 1135821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) unsigned MinAlign = std::min(DstAlign, SrcAlign); 1145821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) unsigned CopyAlign = MI->getAlignment(); 1156d86b77056ed63eb6871182f42a9fd5f07550f90Torne (Richard Coles) 1165821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (CopyAlign < MinAlign) { 1175821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) MI->setAlignment(ConstantInt::get(MI->getAlignmentType(), 1185821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) MinAlign, false)); 1195821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return MI; 1202a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) } 1215821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1225821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // If MemCpyInst length is 1/2/4/8 bytes then replace memcpy with 1235821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // load/store. 1245821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) ConstantInt *MemOpLength = dyn_cast<ConstantInt>(MI->getOperand(3)); 1255821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (MemOpLength == 0) return 0; 1265821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1276d86b77056ed63eb6871182f42a9fd5f07550f90Torne (Richard Coles) // Source and destination pointer types are always "i8*" for intrinsic. See 1286d86b77056ed63eb6871182f42a9fd5f07550f90Torne (Richard Coles) // if the size is something we can handle with a single primitive load/store. 1295821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // A single load+store correctly handles overlapping memory in the memmove 1305821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // case. 1315821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) unsigned Size = MemOpLength->getZExtValue(); 1325821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (Size == 0) return MI; // Delete this mem transfer. 1335821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1345821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (Size > 8 || (Size&(Size-1))) 1355821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return 0; // If not 1/2/4/8 bytes, exit. 1365821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1375821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Use an integer load+store unless we can find something better. 1385821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) Type *NewPtrTy = 1395821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) PointerType::getUnqual(IntegerType::get(MI->getContext(), Size<<3)); 1406d86b77056ed63eb6871182f42a9fd5f07550f90Torne (Richard Coles) 1415821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Memcpy forces the use of i8* for the source and destination. That means 1426d86b77056ed63eb6871182f42a9fd5f07550f90Torne (Richard Coles) // that if you're using memcpy to move one double around, you'll get a cast 1435821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // from double* to i8*. We'd much rather use a double load+store rather than 1446d86b77056ed63eb6871182f42a9fd5f07550f90Torne (Richard Coles) // an i64 load+store, here because this improves the odds that the source or 1455821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // dest address will be promotable. See if we can find a better type than the 1465821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // integer datatype. 1475821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) Value *StrippedDest = MI->getOperand(1)->stripPointerCasts(); 1485821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (StrippedDest != MI->getOperand(1)) { 1495821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) const Type *SrcETy = cast<PointerType>(StrippedDest->getType()) 1505821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) ->getElementType(); 1515821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (TD && SrcETy->isSized() && TD->getTypeStoreSize(SrcETy) == Size) { 1525821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // The SrcETy might be something like {{{double}}} or [1 x double]. Rip 1535821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // down through these levels if so. 1545821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) while (!SrcETy->isSingleValueType()) { 1555821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (const StructType *STy = dyn_cast<StructType>(SrcETy)) { 1565821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (STy->getNumElements() == 1) 1575821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) SrcETy = STy->getElementType(0); 1585821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) else 1595821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) break; 1605821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } else if (const ArrayType *ATy = dyn_cast<ArrayType>(SrcETy)) { 1615821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (ATy->getNumElements() == 1) 1625821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) SrcETy = ATy->getElementType(); 1635821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) else 1645821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) break; 1655821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } else 1665821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) break; 1675821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 1685821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1695821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (SrcETy->isSingleValueType()) 1705821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) NewPtrTy = PointerType::getUnqual(SrcETy); 1715821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 1725821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 1735821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1745821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1755821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // If the memcpy/memmove provides better alignment info than we can 1765821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // infer, use it. 1775821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) SrcAlign = std::max(SrcAlign, CopyAlign); 1785821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) DstAlign = std::max(DstAlign, CopyAlign); 1795821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1802a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) Value *Src = Builder->CreateBitCast(MI->getOperand(2), NewPtrTy); 1815821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) Value *Dest = Builder->CreateBitCast(MI->getOperand(1), NewPtrTy); 1825821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) Instruction *L = new LoadInst(Src, "tmp", false, SrcAlign); 1835821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) InsertNewInstBefore(L, *MI); 1845821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) InsertNewInstBefore(new StoreInst(L, Dest, false, DstAlign), *MI); 1855821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1865821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Set the size of the copy to 0, it will be deleted on the next iteration. 1875821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) MI->setOperand(3, Constant::getNullValue(MemOpLength->getType())); 1885821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return MI; 1895821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 1905821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1915821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)Instruction *InstCombiner::SimplifyMemSet(MemSetInst *MI) { 1925821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) unsigned Alignment = GetOrEnforceKnownAlignment(MI->getDest()); 1935821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (MI->getAlignment() < Alignment) { 1945821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) MI->setAlignment(ConstantInt::get(MI->getAlignmentType(), 1955821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) Alignment, false)); 1965821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return MI; 1975821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 1985821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1995821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Extract the length and alignment and fill if they are constant. 2005821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) ConstantInt *LenC = dyn_cast<ConstantInt>(MI->getLength()); 2014e180b6a0b4720a9b8e9e959a882386f690f08ffTorne (Richard Coles) ConstantInt *FillC = dyn_cast<ConstantInt>(MI->getValue()); 2024e180b6a0b4720a9b8e9e959a882386f690f08ffTorne (Richard Coles) if (!LenC || !FillC || !FillC->getType()->isIntegerTy(8)) 2034e180b6a0b4720a9b8e9e959a882386f690f08ffTorne (Richard Coles) return 0; 2045821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) uint64_t Len = LenC->getZExtValue(); 2052a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) Alignment = MI->getAlignment(); 20603b57e008b61dfcb1fbad3aea950ae0e001748b0Torne (Richard Coles) 2076d86b77056ed63eb6871182f42a9fd5f07550f90Torne (Richard Coles) // If the length is zero, this is a no-op 208a3f6a49ab37290eeeb8db0f41ec0f1cb74a68be7Torne (Richard Coles) if (Len == 0) return MI; // memset(d,c,0,a) -> noop 2095821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 2102a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) // memset(s,c,n) -> store s, c (for n=1,2,4,8) 2116d86b77056ed63eb6871182f42a9fd5f07550f90Torne (Richard Coles) if (Len <= 8 && isPowerOf2_32((uint32_t)Len)) { 2126d86b77056ed63eb6871182f42a9fd5f07550f90Torne (Richard Coles) const Type *ITy = IntegerType::get(MI->getContext(), Len*8); // n=1 -> i8. 2135821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 2145821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) Value *Dest = MI->getDest(); 2152a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) Dest = Builder->CreateBitCast(Dest, PointerType::getUnqual(ITy)); 2166d86b77056ed63eb6871182f42a9fd5f07550f90Torne (Richard Coles) 2176d86b77056ed63eb6871182f42a9fd5f07550f90Torne (Richard Coles) // Alignment 0 is identity for alignment 1 for memset, but not store. 2185821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (Alignment == 0) Alignment = 1; 2195821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 2205821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Extract the fill value and store. 2215821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) uint64_t Fill = FillC->getZExtValue()*0x0101010101010101ULL; 2225821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) InsertNewInstBefore(new StoreInst(ConstantInt::get(ITy, Fill), 2236d86b77056ed63eb6871182f42a9fd5f07550f90Torne (Richard Coles) Dest, false, Alignment), *MI); 2245821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 2255821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Set the size of the copy to 0, it will be deleted on the next iteration. 2265821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) MI->setLength(Constant::getNullValue(LenC->getType())); 2275821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return MI; 2282a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) } 2292a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 2302a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) return 0; 2312a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)} 2322a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 2332a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)/// visitCallInst - CallInst simplification. This mostly only handles folding 2342a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)/// of intrinsic instructions. For normal calls, it allows visitCallSite to do 2352a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)/// the heavy lifting. 2362a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)/// 2372a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)Instruction *InstCombiner::visitCallInst(CallInst &CI) { 2382a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) if (isFreeCall(&CI)) 2392a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) return visitFree(CI); 2402a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 2412a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) // If the caller function is nounwind, mark the call as nounwind, even if the 2422a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) // callee isn't. 2432a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) if (CI.getParent()->getParent()->doesNotThrow() && 2442a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) !CI.doesNotThrow()) { 2452a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) CI.setDoesNotThrow(); 2462a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) return &CI; 2472a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) } 2482a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 2492a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) IntrinsicInst *II = dyn_cast<IntrinsicInst>(&CI); 2502a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) if (!II) return visitCallSite(&CI); 2514e180b6a0b4720a9b8e9e959a882386f690f08ffTorne (Richard Coles) 2524e180b6a0b4720a9b8e9e959a882386f690f08ffTorne (Richard Coles) // Intrinsics cannot occur in an invoke, so handle them here instead of in 2534e180b6a0b4720a9b8e9e959a882386f690f08ffTorne (Richard Coles) // visitCallSite. 2542a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) if (MemIntrinsic *MI = dyn_cast<MemIntrinsic>(II)) { 2552a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) bool Changed = false; 2562a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 2572a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) // memmove/cpy/set of zero bytes is a noop. 2582a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) if (Constant *NumBytes = dyn_cast<Constant>(MI->getLength())) { 2592a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) if (NumBytes->isNullValue()) return EraseInstFromFunction(CI); 2602a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 2612a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) if (ConstantInt *CI = dyn_cast<ConstantInt>(NumBytes)) 2622a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) if (CI->getZExtValue() == 1) { 2632a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) // Replace the instruction with just byte operations. We would 2642a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) // transform other cases to loads/stores, but we don't know if 2652a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) // alignment is sufficient. 2662a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) } 2672a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) } 2682a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 2692a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) // If we have a memmove and the source operation is a constant global, 2702a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) // then the source and dest pointers can't alias, so we can change this 2712a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) // into a call to memcpy. 2722a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) if (MemMoveInst *MMI = dyn_cast<MemMoveInst>(MI)) { 2732a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) if (GlobalVariable *GVSrc = dyn_cast<GlobalVariable>(MMI->getSource())) 2745821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (GVSrc->isConstant()) { 2755821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) Module *M = CI.getParent()->getParent()->getParent(); 2762a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) Intrinsic::ID MemCpyID = Intrinsic::memcpy; 277a3f6a49ab37290eeeb8db0f41ec0f1cb74a68be7Torne (Richard Coles) const Type *Tys[1]; 2785821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) Tys[0] = CI.getOperand(3)->getType(); 2795821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) CI.setOperand(0, 2805821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) Intrinsic::getDeclaration(M, MemCpyID, Tys, 1)); 2815821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) Changed = true; 2822a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) } 2832a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) } 2846d86b77056ed63eb6871182f42a9fd5f07550f90Torne (Richard Coles) 2855821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (MemTransferInst *MTI = dyn_cast<MemTransferInst>(MI)) { 2865821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // memmove(x,x,size) -> noop. 2875821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (MTI->getSource() == MTI->getDest()) 2885821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return EraseInstFromFunction(CI); 2895821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 2905821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 2915821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // If we can determine a pointer alignment that is bigger than currently 2922a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) // set, update the alignment. 2936d86b77056ed63eb6871182f42a9fd5f07550f90Torne (Richard Coles) if (isa<MemTransferInst>(MI)) { 2945821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (Instruction *I = SimplifyMemTransfer(MI)) 2955821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return I; 2962a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) } else if (MemSetInst *MSI = dyn_cast<MemSetInst>(MI)) { 2972a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) if (Instruction *I = SimplifyMemSet(MSI)) 2982a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) return I; 2992a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) } 3002a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 3012a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) if (Changed) return II; 30203b57e008b61dfcb1fbad3aea950ae0e001748b0Torne (Richard Coles) } 3032a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 3042a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) switch (II->getIntrinsicID()) { 3052a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) default: break; 30603b57e008b61dfcb1fbad3aea950ae0e001748b0Torne (Richard Coles) case Intrinsic::objectsize: { 3072a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) const Type *ReturnTy = CI.getType(); 30803b57e008b61dfcb1fbad3aea950ae0e001748b0Torne (Richard Coles) Value *Op1 = II->getOperand(1); 3092a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) bool Min = (cast<ConstantInt>(II->getOperand(2))->getZExtValue() == 1); 31003b57e008b61dfcb1fbad3aea950ae0e001748b0Torne (Richard Coles) 3112a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) // We need target data for just about everything so depend on it. 31203b57e008b61dfcb1fbad3aea950ae0e001748b0Torne (Richard Coles) if (!TD) break; 3132a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 3142a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) // Get to the real allocated thing and offset as fast as possible. 31503b57e008b61dfcb1fbad3aea950ae0e001748b0Torne (Richard Coles) Op1 = Op1->stripPointerCasts(); 3162a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) 31703b57e008b61dfcb1fbad3aea950ae0e001748b0Torne (Richard Coles) // If we've stripped down to a single global variable that we 3182a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) // can know the size of then just return that. 31903b57e008b61dfcb1fbad3aea950ae0e001748b0Torne (Richard Coles) if (GlobalVariable *GV = dyn_cast<GlobalVariable>(Op1)) { 3202a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) if (GV->hasDefinitiveInitializer()) { 32103b57e008b61dfcb1fbad3aea950ae0e001748b0Torne (Richard Coles) Constant *C = GV->getInitializer(); 3222a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) size_t globalSize = TD->getTypeAllocSize(C->getType()); 3232a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) return ReplaceInstUsesWith(CI, ConstantInt::get(ReturnTy, globalSize)); 32490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } else { 32590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) Constant *RetVal = ConstantInt::get(ReturnTy, Min ? 0 : -1ULL); 32690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return ReplaceInstUsesWith(CI, RetVal); 32703b57e008b61dfcb1fbad3aea950ae0e001748b0Torne (Richard Coles) } 32890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } else if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Op1)) { 32990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 33003b57e008b61dfcb1fbad3aea950ae0e001748b0Torne (Richard Coles) // Only handle constant GEPs here. 33103b57e008b61dfcb1fbad3aea950ae0e001748b0Torne (Richard Coles) if (CE->getOpcode() != Instruction::GetElementPtr) break; 33290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) GEPOperator *GEP = cast<GEPOperator>(CE); 33390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 33490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Make sure we're not a constant offset from an external 33590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // global. 33690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) Value *Operand = GEP->getPointerOperand(); 33790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) Operand = Operand->stripPointerCasts(); 33890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (GlobalVariable *GV = dyn_cast<GlobalVariable>(Operand)) 33990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (!GV->hasDefinitiveInitializer()) break; 34003b57e008b61dfcb1fbad3aea950ae0e001748b0Torne (Richard Coles) 34190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Get what we're pointing to and its size. 34290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) const PointerType *BaseType = 34390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) cast<PointerType>(Operand->getType()); 34490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) size_t Size = TD->getTypeAllocSize(BaseType->getElementType()); 34590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 34690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Get the current byte offset into the thing. Use the original 34790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // operand in case we're looking through a bitcast. 34890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) SmallVector<Value*, 8> Ops(CE->op_begin()+1, CE->op_end()); 34990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) const PointerType *OffsetType = 35090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) cast<PointerType>(GEP->getPointerOperand()->getType()); 3516d86b77056ed63eb6871182f42a9fd5f07550f90Torne (Richard Coles) size_t Offset = TD->getIndexedOffset(OffsetType, &Ops[0], Ops.size()); 352a3f6a49ab37290eeeb8db0f41ec0f1cb74a68be7Torne (Richard Coles) 35390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) assert(Size >= Offset); 3546d86b77056ed63eb6871182f42a9fd5f07550f90Torne (Richard Coles) 3556d86b77056ed63eb6871182f42a9fd5f07550f90Torne (Richard Coles) Constant *RetVal = ConstantInt::get(ReturnTy, Size-Offset); 35690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return ReplaceInstUsesWith(CI, RetVal); 35790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 3586d86b77056ed63eb6871182f42a9fd5f07550f90Torne (Richard Coles) } 35990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 36090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case Intrinsic::bswap: 3615c02ac1a9c1b504631c0a3d2b6e737b5d738bae1Bo Liu // bswap(bswap(x)) -> x 362 if (IntrinsicInst *Operand = dyn_cast<IntrinsicInst>(II->getOperand(1))) 363 if (Operand->getIntrinsicID() == Intrinsic::bswap) 364 return ReplaceInstUsesWith(CI, Operand->getOperand(1)); 365 366 // bswap(trunc(bswap(x))) -> trunc(lshr(x, c)) 367 if (TruncInst *TI = dyn_cast<TruncInst>(II->getOperand(1))) { 368 if (IntrinsicInst *Operand = dyn_cast<IntrinsicInst>(TI->getOperand(0))) 369 if (Operand->getIntrinsicID() == Intrinsic::bswap) { 370 unsigned C = Operand->getType()->getPrimitiveSizeInBits() - 371 TI->getType()->getPrimitiveSizeInBits(); 372 Value *CV = ConstantInt::get(Operand->getType(), C); 373 Value *V = Builder->CreateLShr(Operand->getOperand(1), CV); 374 return new TruncInst(V, TI->getType()); 375 } 376 } 377 378 break; 379 case Intrinsic::powi: 380 if (ConstantInt *Power = dyn_cast<ConstantInt>(II->getOperand(2))) { 381 // powi(x, 0) -> 1.0 382 if (Power->isZero()) 383 return ReplaceInstUsesWith(CI, ConstantFP::get(CI.getType(), 1.0)); 384 // powi(x, 1) -> x 385 if (Power->isOne()) 386 return ReplaceInstUsesWith(CI, II->getOperand(1)); 387 // powi(x, -1) -> 1/x 388 if (Power->isAllOnesValue()) 389 return BinaryOperator::CreateFDiv(ConstantFP::get(CI.getType(), 1.0), 390 II->getOperand(1)); 391 } 392 break; 393 case Intrinsic::cttz: { 394 // If all bits below the first known one are known zero, 395 // this value is constant. 396 const IntegerType *IT = cast<IntegerType>(II->getOperand(1)->getType()); 397 uint32_t BitWidth = IT->getBitWidth(); 398 APInt KnownZero(BitWidth, 0); 399 APInt KnownOne(BitWidth, 0); 400 ComputeMaskedBits(II->getOperand(1), APInt::getAllOnesValue(BitWidth), 401 KnownZero, KnownOne); 402 unsigned TrailingZeros = KnownOne.countTrailingZeros(); 403 APInt Mask(APInt::getLowBitsSet(BitWidth, TrailingZeros)); 404 if ((Mask & KnownZero) == Mask) 405 return ReplaceInstUsesWith(CI, ConstantInt::get(IT, 406 APInt(BitWidth, TrailingZeros))); 407 408 } 409 break; 410 case Intrinsic::ctlz: { 411 // If all bits above the first known one are known zero, 412 // this value is constant. 413 const IntegerType *IT = cast<IntegerType>(II->getOperand(1)->getType()); 414 uint32_t BitWidth = IT->getBitWidth(); 415 APInt KnownZero(BitWidth, 0); 416 APInt KnownOne(BitWidth, 0); 417 ComputeMaskedBits(II->getOperand(1), APInt::getAllOnesValue(BitWidth), 418 KnownZero, KnownOne); 419 unsigned LeadingZeros = KnownOne.countLeadingZeros(); 420 APInt Mask(APInt::getHighBitsSet(BitWidth, LeadingZeros)); 421 if ((Mask & KnownZero) == Mask) 422 return ReplaceInstUsesWith(CI, ConstantInt::get(IT, 423 APInt(BitWidth, LeadingZeros))); 424 425 } 426 break; 427 case Intrinsic::uadd_with_overflow: { 428 Value *LHS = II->getOperand(1), *RHS = II->getOperand(2); 429 const IntegerType *IT = cast<IntegerType>(II->getOperand(1)->getType()); 430 uint32_t BitWidth = IT->getBitWidth(); 431 APInt Mask = APInt::getSignBit(BitWidth); 432 APInt LHSKnownZero(BitWidth, 0); 433 APInt LHSKnownOne(BitWidth, 0); 434 ComputeMaskedBits(LHS, Mask, LHSKnownZero, LHSKnownOne); 435 bool LHSKnownNegative = LHSKnownOne[BitWidth - 1]; 436 bool LHSKnownPositive = LHSKnownZero[BitWidth - 1]; 437 438 if (LHSKnownNegative || LHSKnownPositive) { 439 APInt RHSKnownZero(BitWidth, 0); 440 APInt RHSKnownOne(BitWidth, 0); 441 ComputeMaskedBits(RHS, Mask, RHSKnownZero, RHSKnownOne); 442 bool RHSKnownNegative = RHSKnownOne[BitWidth - 1]; 443 bool RHSKnownPositive = RHSKnownZero[BitWidth - 1]; 444 if (LHSKnownNegative && RHSKnownNegative) { 445 // The sign bit is set in both cases: this MUST overflow. 446 // Create a simple add instruction, and insert it into the struct. 447 Instruction *Add = BinaryOperator::CreateAdd(LHS, RHS, "", &CI); 448 Worklist.Add(Add); 449 Constant *V[] = { 450 UndefValue::get(LHS->getType()),ConstantInt::getTrue(II->getContext()) 451 }; 452 Constant *Struct = ConstantStruct::get(II->getContext(), V, 2, false); 453 return InsertValueInst::Create(Struct, Add, 0); 454 } 455 456 if (LHSKnownPositive && RHSKnownPositive) { 457 // The sign bit is clear in both cases: this CANNOT overflow. 458 // Create a simple add instruction, and insert it into the struct. 459 Instruction *Add = BinaryOperator::CreateNUWAdd(LHS, RHS, "", &CI); 460 Worklist.Add(Add); 461 Constant *V[] = { 462 UndefValue::get(LHS->getType()), 463 ConstantInt::getFalse(II->getContext()) 464 }; 465 Constant *Struct = ConstantStruct::get(II->getContext(), V, 2, false); 466 return InsertValueInst::Create(Struct, Add, 0); 467 } 468 } 469 } 470 // FALL THROUGH uadd into sadd 471 case Intrinsic::sadd_with_overflow: 472 // Canonicalize constants into the RHS. 473 if (isa<Constant>(II->getOperand(1)) && 474 !isa<Constant>(II->getOperand(2))) { 475 Value *LHS = II->getOperand(1); 476 II->setOperand(1, II->getOperand(2)); 477 II->setOperand(2, LHS); 478 return II; 479 } 480 481 // X + undef -> undef 482 if (isa<UndefValue>(II->getOperand(2))) 483 return ReplaceInstUsesWith(CI, UndefValue::get(II->getType())); 484 485 if (ConstantInt *RHS = dyn_cast<ConstantInt>(II->getOperand(2))) { 486 // X + 0 -> {X, false} 487 if (RHS->isZero()) { 488 Constant *V[] = { 489 UndefValue::get(II->getOperand(0)->getType()), 490 ConstantInt::getFalse(II->getContext()) 491 }; 492 Constant *Struct = ConstantStruct::get(II->getContext(), V, 2, false); 493 return InsertValueInst::Create(Struct, II->getOperand(1), 0); 494 } 495 } 496 break; 497 case Intrinsic::usub_with_overflow: 498 case Intrinsic::ssub_with_overflow: 499 // undef - X -> undef 500 // X - undef -> undef 501 if (isa<UndefValue>(II->getOperand(1)) || 502 isa<UndefValue>(II->getOperand(2))) 503 return ReplaceInstUsesWith(CI, UndefValue::get(II->getType())); 504 505 if (ConstantInt *RHS = dyn_cast<ConstantInt>(II->getOperand(2))) { 506 // X - 0 -> {X, false} 507 if (RHS->isZero()) { 508 Constant *V[] = { 509 UndefValue::get(II->getOperand(1)->getType()), 510 ConstantInt::getFalse(II->getContext()) 511 }; 512 Constant *Struct = ConstantStruct::get(II->getContext(), V, 2, false); 513 return InsertValueInst::Create(Struct, II->getOperand(1), 0); 514 } 515 } 516 break; 517 case Intrinsic::umul_with_overflow: 518 case Intrinsic::smul_with_overflow: 519 // Canonicalize constants into the RHS. 520 if (isa<Constant>(II->getOperand(1)) && 521 !isa<Constant>(II->getOperand(2))) { 522 Value *LHS = II->getOperand(1); 523 II->setOperand(1, II->getOperand(2)); 524 II->setOperand(2, LHS); 525 return II; 526 } 527 528 // X * undef -> undef 529 if (isa<UndefValue>(II->getOperand(2))) 530 return ReplaceInstUsesWith(CI, UndefValue::get(II->getType())); 531 532 if (ConstantInt *RHSI = dyn_cast<ConstantInt>(II->getOperand(2))) { 533 // X*0 -> {0, false} 534 if (RHSI->isZero()) 535 return ReplaceInstUsesWith(CI, Constant::getNullValue(II->getType())); 536 537 // X * 1 -> {X, false} 538 if (RHSI->equalsInt(1)) { 539 Constant *V[] = { 540 UndefValue::get(II->getOperand(1)->getType()), 541 ConstantInt::getFalse(II->getContext()) 542 }; 543 Constant *Struct = ConstantStruct::get(II->getContext(), V, 2, false); 544 return InsertValueInst::Create(Struct, II->getOperand(1), 0); 545 } 546 } 547 break; 548 case Intrinsic::ppc_altivec_lvx: 549 case Intrinsic::ppc_altivec_lvxl: 550 case Intrinsic::x86_sse_loadu_ps: 551 case Intrinsic::x86_sse2_loadu_pd: 552 case Intrinsic::x86_sse2_loadu_dq: 553 // Turn PPC lvx -> load if the pointer is known aligned. 554 // Turn X86 loadups -> load if the pointer is known aligned. 555 if (GetOrEnforceKnownAlignment(II->getOperand(1), 16) >= 16) { 556 Value *Ptr = Builder->CreateBitCast(II->getOperand(1), 557 PointerType::getUnqual(II->getType())); 558 return new LoadInst(Ptr); 559 } 560 break; 561 case Intrinsic::ppc_altivec_stvx: 562 case Intrinsic::ppc_altivec_stvxl: 563 // Turn stvx -> store if the pointer is known aligned. 564 if (GetOrEnforceKnownAlignment(II->getOperand(2), 16) >= 16) { 565 const Type *OpPtrTy = 566 PointerType::getUnqual(II->getOperand(1)->getType()); 567 Value *Ptr = Builder->CreateBitCast(II->getOperand(2), OpPtrTy); 568 return new StoreInst(II->getOperand(1), Ptr); 569 } 570 break; 571 case Intrinsic::x86_sse_storeu_ps: 572 case Intrinsic::x86_sse2_storeu_pd: 573 case Intrinsic::x86_sse2_storeu_dq: 574 // Turn X86 storeu -> store if the pointer is known aligned. 575 if (GetOrEnforceKnownAlignment(II->getOperand(1), 16) >= 16) { 576 const Type *OpPtrTy = 577 PointerType::getUnqual(II->getOperand(2)->getType()); 578 Value *Ptr = Builder->CreateBitCast(II->getOperand(1), OpPtrTy); 579 return new StoreInst(II->getOperand(2), Ptr); 580 } 581 break; 582 583 case Intrinsic::x86_sse_cvttss2si: { 584 // These intrinsics only demands the 0th element of its input vector. If 585 // we can simplify the input based on that, do so now. 586 unsigned VWidth = 587 cast<VectorType>(II->getOperand(1)->getType())->getNumElements(); 588 APInt DemandedElts(VWidth, 1); 589 APInt UndefElts(VWidth, 0); 590 if (Value *V = SimplifyDemandedVectorElts(II->getOperand(1), DemandedElts, 591 UndefElts)) { 592 II->setOperand(1, V); 593 return II; 594 } 595 break; 596 } 597 598 case Intrinsic::ppc_altivec_vperm: 599 // Turn vperm(V1,V2,mask) -> shuffle(V1,V2,mask) if mask is a constant. 600 if (ConstantVector *Mask = dyn_cast<ConstantVector>(II->getOperand(3))) { 601 assert(Mask->getNumOperands() == 16 && "Bad type for intrinsic!"); 602 603 // Check that all of the elements are integer constants or undefs. 604 bool AllEltsOk = true; 605 for (unsigned i = 0; i != 16; ++i) { 606 if (!isa<ConstantInt>(Mask->getOperand(i)) && 607 !isa<UndefValue>(Mask->getOperand(i))) { 608 AllEltsOk = false; 609 break; 610 } 611 } 612 613 if (AllEltsOk) { 614 // Cast the input vectors to byte vectors. 615 Value *Op0 = Builder->CreateBitCast(II->getOperand(1), Mask->getType()); 616 Value *Op1 = Builder->CreateBitCast(II->getOperand(2), Mask->getType()); 617 Value *Result = UndefValue::get(Op0->getType()); 618 619 // Only extract each element once. 620 Value *ExtractedElts[32]; 621 memset(ExtractedElts, 0, sizeof(ExtractedElts)); 622 623 for (unsigned i = 0; i != 16; ++i) { 624 if (isa<UndefValue>(Mask->getOperand(i))) 625 continue; 626 unsigned Idx=cast<ConstantInt>(Mask->getOperand(i))->getZExtValue(); 627 Idx &= 31; // Match the hardware behavior. 628 629 if (ExtractedElts[Idx] == 0) { 630 ExtractedElts[Idx] = 631 Builder->CreateExtractElement(Idx < 16 ? Op0 : Op1, 632 ConstantInt::get(Type::getInt32Ty(II->getContext()), 633 Idx&15, false), "tmp"); 634 } 635 636 // Insert this value into the result vector. 637 Result = Builder->CreateInsertElement(Result, ExtractedElts[Idx], 638 ConstantInt::get(Type::getInt32Ty(II->getContext()), 639 i, false), "tmp"); 640 } 641 return CastInst::Create(Instruction::BitCast, Result, CI.getType()); 642 } 643 } 644 break; 645 646 case Intrinsic::stackrestore: { 647 // If the save is right next to the restore, remove the restore. This can 648 // happen when variable allocas are DCE'd. 649 if (IntrinsicInst *SS = dyn_cast<IntrinsicInst>(II->getOperand(1))) { 650 if (SS->getIntrinsicID() == Intrinsic::stacksave) { 651 BasicBlock::iterator BI = SS; 652 if (&*++BI == II) 653 return EraseInstFromFunction(CI); 654 } 655 } 656 657 // Scan down this block to see if there is another stack restore in the 658 // same block without an intervening call/alloca. 659 BasicBlock::iterator BI = II; 660 TerminatorInst *TI = II->getParent()->getTerminator(); 661 bool CannotRemove = false; 662 for (++BI; &*BI != TI; ++BI) { 663 if (isa<AllocaInst>(BI) || isMalloc(BI)) { 664 CannotRemove = true; 665 break; 666 } 667 if (CallInst *BCI = dyn_cast<CallInst>(BI)) { 668 if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(BCI)) { 669 // If there is a stackrestore below this one, remove this one. 670 if (II->getIntrinsicID() == Intrinsic::stackrestore) 671 return EraseInstFromFunction(CI); 672 // Otherwise, ignore the intrinsic. 673 } else { 674 // If we found a non-intrinsic call, we can't remove the stack 675 // restore. 676 CannotRemove = true; 677 break; 678 } 679 } 680 } 681 682 // If the stack restore is in a return/unwind block and if there are no 683 // allocas or calls between the restore and the return, nuke the restore. 684 if (!CannotRemove && (isa<ReturnInst>(TI) || isa<UnwindInst>(TI))) 685 return EraseInstFromFunction(CI); 686 break; 687 } 688 } 689 690 return visitCallSite(II); 691} 692 693// InvokeInst simplification 694// 695Instruction *InstCombiner::visitInvokeInst(InvokeInst &II) { 696 return visitCallSite(&II); 697} 698 699/// isSafeToEliminateVarargsCast - If this cast does not affect the value 700/// passed through the varargs area, we can eliminate the use of the cast. 701static bool isSafeToEliminateVarargsCast(const CallSite CS, 702 const CastInst * const CI, 703 const TargetData * const TD, 704 const int ix) { 705 if (!CI->isLosslessCast()) 706 return false; 707 708 // The size of ByVal arguments is derived from the type, so we 709 // can't change to a type with a different size. If the size were 710 // passed explicitly we could avoid this check. 711 if (!CS.paramHasAttr(ix, Attribute::ByVal)) 712 return true; 713 714 const Type* SrcTy = 715 cast<PointerType>(CI->getOperand(0)->getType())->getElementType(); 716 const Type* DstTy = cast<PointerType>(CI->getType())->getElementType(); 717 if (!SrcTy->isSized() || !DstTy->isSized()) 718 return false; 719 if (!TD || TD->getTypeAllocSize(SrcTy) != TD->getTypeAllocSize(DstTy)) 720 return false; 721 return true; 722} 723 724// visitCallSite - Improvements for call and invoke instructions. 725// 726Instruction *InstCombiner::visitCallSite(CallSite CS) { 727 bool Changed = false; 728 729 // If the callee is a constexpr cast of a function, attempt to move the cast 730 // to the arguments of the call/invoke. 731 if (transformConstExprCastCall(CS)) return 0; 732 733 Value *Callee = CS.getCalledValue(); 734 735 if (Function *CalleeF = dyn_cast<Function>(Callee)) 736 // If the call and callee calling conventions don't match, this call must 737 // be unreachable, as the call is undefined. 738 if (CalleeF->getCallingConv() != CS.getCallingConv() && 739 // Only do this for calls to a function with a body. A prototype may 740 // not actually end up matching the implementation's calling conv for a 741 // variety of reasons (e.g. it may be written in assembly). 742 !CalleeF->isDeclaration()) { 743 Instruction *OldCall = CS.getInstruction(); 744 new StoreInst(ConstantInt::getTrue(Callee->getContext()), 745 UndefValue::get(Type::getInt1PtrTy(Callee->getContext())), 746 OldCall); 747 // If OldCall dues not return void then replaceAllUsesWith undef. 748 // This allows ValueHandlers and custom metadata to adjust itself. 749 if (!OldCall->getType()->isVoidTy()) 750 OldCall->replaceAllUsesWith(UndefValue::get(OldCall->getType())); 751 if (isa<CallInst>(OldCall)) 752 return EraseInstFromFunction(*OldCall); 753 754 // We cannot remove an invoke, because it would change the CFG, just 755 // change the callee to a null pointer. 756 cast<InvokeInst>(OldCall)->setOperand(0, 757 Constant::getNullValue(CalleeF->getType())); 758 return 0; 759 } 760 761 if (isa<ConstantPointerNull>(Callee) || isa<UndefValue>(Callee)) { 762 // This instruction is not reachable, just remove it. We insert a store to 763 // undef so that we know that this code is not reachable, despite the fact 764 // that we can't modify the CFG here. 765 new StoreInst(ConstantInt::getTrue(Callee->getContext()), 766 UndefValue::get(Type::getInt1PtrTy(Callee->getContext())), 767 CS.getInstruction()); 768 769 // If CS dues not return void then replaceAllUsesWith undef. 770 // This allows ValueHandlers and custom metadata to adjust itself. 771 if (!CS.getInstruction()->getType()->isVoidTy()) 772 CS.getInstruction()-> 773 replaceAllUsesWith(UndefValue::get(CS.getInstruction()->getType())); 774 775 if (InvokeInst *II = dyn_cast<InvokeInst>(CS.getInstruction())) { 776 // Don't break the CFG, insert a dummy cond branch. 777 BranchInst::Create(II->getNormalDest(), II->getUnwindDest(), 778 ConstantInt::getTrue(Callee->getContext()), II); 779 } 780 return EraseInstFromFunction(*CS.getInstruction()); 781 } 782 783 if (BitCastInst *BC = dyn_cast<BitCastInst>(Callee)) 784 if (IntrinsicInst *In = dyn_cast<IntrinsicInst>(BC->getOperand(0))) 785 if (In->getIntrinsicID() == Intrinsic::init_trampoline) 786 return transformCallThroughTrampoline(CS); 787 788 const PointerType *PTy = cast<PointerType>(Callee->getType()); 789 const FunctionType *FTy = cast<FunctionType>(PTy->getElementType()); 790 if (FTy->isVarArg()) { 791 int ix = FTy->getNumParams() + (isa<InvokeInst>(Callee) ? 3 : 1); 792 // See if we can optimize any arguments passed through the varargs area of 793 // the call. 794 for (CallSite::arg_iterator I = CS.arg_begin()+FTy->getNumParams(), 795 E = CS.arg_end(); I != E; ++I, ++ix) { 796 CastInst *CI = dyn_cast<CastInst>(*I); 797 if (CI && isSafeToEliminateVarargsCast(CS, CI, TD, ix)) { 798 *I = CI->getOperand(0); 799 Changed = true; 800 } 801 } 802 } 803 804 if (isa<InlineAsm>(Callee) && !CS.doesNotThrow()) { 805 // Inline asm calls cannot throw - mark them 'nounwind'. 806 CS.setDoesNotThrow(); 807 Changed = true; 808 } 809 810 return Changed ? CS.getInstruction() : 0; 811} 812 813// transformConstExprCastCall - If the callee is a constexpr cast of a function, 814// attempt to move the cast to the arguments of the call/invoke. 815// 816bool InstCombiner::transformConstExprCastCall(CallSite CS) { 817 if (!isa<ConstantExpr>(CS.getCalledValue())) return false; 818 ConstantExpr *CE = cast<ConstantExpr>(CS.getCalledValue()); 819 if (CE->getOpcode() != Instruction::BitCast || 820 !isa<Function>(CE->getOperand(0))) 821 return false; 822 Function *Callee = cast<Function>(CE->getOperand(0)); 823 Instruction *Caller = CS.getInstruction(); 824 const AttrListPtr &CallerPAL = CS.getAttributes(); 825 826 // Okay, this is a cast from a function to a different type. Unless doing so 827 // would cause a type conversion of one of our arguments, change this call to 828 // be a direct call with arguments casted to the appropriate types. 829 // 830 const FunctionType *FT = Callee->getFunctionType(); 831 const Type *OldRetTy = Caller->getType(); 832 const Type *NewRetTy = FT->getReturnType(); 833 834 if (NewRetTy->isStructTy()) 835 return false; // TODO: Handle multiple return values. 836 837 // Check to see if we are changing the return type... 838 if (OldRetTy != NewRetTy) { 839 if (Callee->isDeclaration() && 840 // Conversion is ok if changing from one pointer type to another or from 841 // a pointer to an integer of the same size. 842 !((OldRetTy->isPointerTy() || !TD || 843 OldRetTy == TD->getIntPtrType(Caller->getContext())) && 844 (NewRetTy->isPointerTy() || !TD || 845 NewRetTy == TD->getIntPtrType(Caller->getContext())))) 846 return false; // Cannot transform this return value. 847 848 if (!Caller->use_empty() && 849 // void -> non-void is handled specially 850 !NewRetTy->isVoidTy() && !CastInst::isCastable(NewRetTy, OldRetTy)) 851 return false; // Cannot transform this return value. 852 853 if (!CallerPAL.isEmpty() && !Caller->use_empty()) { 854 Attributes RAttrs = CallerPAL.getRetAttributes(); 855 if (RAttrs & Attribute::typeIncompatible(NewRetTy)) 856 return false; // Attribute not compatible with transformed value. 857 } 858 859 // If the callsite is an invoke instruction, and the return value is used by 860 // a PHI node in a successor, we cannot change the return type of the call 861 // because there is no place to put the cast instruction (without breaking 862 // the critical edge). Bail out in this case. 863 if (!Caller->use_empty()) 864 if (InvokeInst *II = dyn_cast<InvokeInst>(Caller)) 865 for (Value::use_iterator UI = II->use_begin(), E = II->use_end(); 866 UI != E; ++UI) 867 if (PHINode *PN = dyn_cast<PHINode>(*UI)) 868 if (PN->getParent() == II->getNormalDest() || 869 PN->getParent() == II->getUnwindDest()) 870 return false; 871 } 872 873 unsigned NumActualArgs = unsigned(CS.arg_end()-CS.arg_begin()); 874 unsigned NumCommonArgs = std::min(FT->getNumParams(), NumActualArgs); 875 876 CallSite::arg_iterator AI = CS.arg_begin(); 877 for (unsigned i = 0, e = NumCommonArgs; i != e; ++i, ++AI) { 878 const Type *ParamTy = FT->getParamType(i); 879 const Type *ActTy = (*AI)->getType(); 880 881 if (!CastInst::isCastable(ActTy, ParamTy)) 882 return false; // Cannot transform this parameter value. 883 884 if (CallerPAL.getParamAttributes(i + 1) 885 & Attribute::typeIncompatible(ParamTy)) 886 return false; // Attribute not compatible with transformed value. 887 888 // Converting from one pointer type to another or between a pointer and an 889 // integer of the same size is safe even if we do not have a body. 890 bool isConvertible = ActTy == ParamTy || 891 (TD && ((ParamTy->isPointerTy() || 892 ParamTy == TD->getIntPtrType(Caller->getContext())) && 893 (ActTy->isPointerTy() || 894 ActTy == TD->getIntPtrType(Caller->getContext())))); 895 if (Callee->isDeclaration() && !isConvertible) return false; 896 } 897 898 if (FT->getNumParams() < NumActualArgs && !FT->isVarArg() && 899 Callee->isDeclaration()) 900 return false; // Do not delete arguments unless we have a function body. 901 902 if (FT->getNumParams() < NumActualArgs && FT->isVarArg() && 903 !CallerPAL.isEmpty()) 904 // In this case we have more arguments than the new function type, but we 905 // won't be dropping them. Check that these extra arguments have attributes 906 // that are compatible with being a vararg call argument. 907 for (unsigned i = CallerPAL.getNumSlots(); i; --i) { 908 if (CallerPAL.getSlot(i - 1).Index <= FT->getNumParams()) 909 break; 910 Attributes PAttrs = CallerPAL.getSlot(i - 1).Attrs; 911 if (PAttrs & Attribute::VarArgsIncompatible) 912 return false; 913 } 914 915 // Okay, we decided that this is a safe thing to do: go ahead and start 916 // inserting cast instructions as necessary... 917 std::vector<Value*> Args; 918 Args.reserve(NumActualArgs); 919 SmallVector<AttributeWithIndex, 8> attrVec; 920 attrVec.reserve(NumCommonArgs); 921 922 // Get any return attributes. 923 Attributes RAttrs = CallerPAL.getRetAttributes(); 924 925 // If the return value is not being used, the type may not be compatible 926 // with the existing attributes. Wipe out any problematic attributes. 927 RAttrs &= ~Attribute::typeIncompatible(NewRetTy); 928 929 // Add the new return attributes. 930 if (RAttrs) 931 attrVec.push_back(AttributeWithIndex::get(0, RAttrs)); 932 933 AI = CS.arg_begin(); 934 for (unsigned i = 0; i != NumCommonArgs; ++i, ++AI) { 935 const Type *ParamTy = FT->getParamType(i); 936 if ((*AI)->getType() == ParamTy) { 937 Args.push_back(*AI); 938 } else { 939 Instruction::CastOps opcode = CastInst::getCastOpcode(*AI, 940 false, ParamTy, false); 941 Args.push_back(Builder->CreateCast(opcode, *AI, ParamTy, "tmp")); 942 } 943 944 // Add any parameter attributes. 945 if (Attributes PAttrs = CallerPAL.getParamAttributes(i + 1)) 946 attrVec.push_back(AttributeWithIndex::get(i + 1, PAttrs)); 947 } 948 949 // If the function takes more arguments than the call was taking, add them 950 // now. 951 for (unsigned i = NumCommonArgs; i != FT->getNumParams(); ++i) 952 Args.push_back(Constant::getNullValue(FT->getParamType(i))); 953 954 // If we are removing arguments to the function, emit an obnoxious warning. 955 if (FT->getNumParams() < NumActualArgs) { 956 if (!FT->isVarArg()) { 957 errs() << "WARNING: While resolving call to function '" 958 << Callee->getName() << "' arguments were dropped!\n"; 959 } else { 960 // Add all of the arguments in their promoted form to the arg list. 961 for (unsigned i = FT->getNumParams(); i != NumActualArgs; ++i, ++AI) { 962 const Type *PTy = getPromotedType((*AI)->getType()); 963 if (PTy != (*AI)->getType()) { 964 // Must promote to pass through va_arg area! 965 Instruction::CastOps opcode = 966 CastInst::getCastOpcode(*AI, false, PTy, false); 967 Args.push_back(Builder->CreateCast(opcode, *AI, PTy, "tmp")); 968 } else { 969 Args.push_back(*AI); 970 } 971 972 // Add any parameter attributes. 973 if (Attributes PAttrs = CallerPAL.getParamAttributes(i + 1)) 974 attrVec.push_back(AttributeWithIndex::get(i + 1, PAttrs)); 975 } 976 } 977 } 978 979 if (Attributes FnAttrs = CallerPAL.getFnAttributes()) 980 attrVec.push_back(AttributeWithIndex::get(~0, FnAttrs)); 981 982 if (NewRetTy->isVoidTy()) 983 Caller->setName(""); // Void type should not have a name. 984 985 const AttrListPtr &NewCallerPAL = AttrListPtr::get(attrVec.begin(), 986 attrVec.end()); 987 988 Instruction *NC; 989 if (InvokeInst *II = dyn_cast<InvokeInst>(Caller)) { 990 NC = InvokeInst::Create(Callee, II->getNormalDest(), II->getUnwindDest(), 991 Args.begin(), Args.end(), 992 Caller->getName(), Caller); 993 cast<InvokeInst>(NC)->setCallingConv(II->getCallingConv()); 994 cast<InvokeInst>(NC)->setAttributes(NewCallerPAL); 995 } else { 996 NC = CallInst::Create(Callee, Args.begin(), Args.end(), 997 Caller->getName(), Caller); 998 CallInst *CI = cast<CallInst>(Caller); 999 if (CI->isTailCall()) 1000 cast<CallInst>(NC)->setTailCall(); 1001 cast<CallInst>(NC)->setCallingConv(CI->getCallingConv()); 1002 cast<CallInst>(NC)->setAttributes(NewCallerPAL); 1003 } 1004 1005 // Insert a cast of the return type as necessary. 1006 Value *NV = NC; 1007 if (OldRetTy != NV->getType() && !Caller->use_empty()) { 1008 if (!NV->getType()->isVoidTy()) { 1009 Instruction::CastOps opcode = CastInst::getCastOpcode(NC, false, 1010 OldRetTy, false); 1011 NV = NC = CastInst::Create(opcode, NC, OldRetTy, "tmp"); 1012 1013 // If this is an invoke instruction, we should insert it after the first 1014 // non-phi, instruction in the normal successor block. 1015 if (InvokeInst *II = dyn_cast<InvokeInst>(Caller)) { 1016 BasicBlock::iterator I = II->getNormalDest()->getFirstNonPHI(); 1017 InsertNewInstBefore(NC, *I); 1018 } else { 1019 // Otherwise, it's a call, just insert cast right after the call instr 1020 InsertNewInstBefore(NC, *Caller); 1021 } 1022 Worklist.AddUsersToWorkList(*Caller); 1023 } else { 1024 NV = UndefValue::get(Caller->getType()); 1025 } 1026 } 1027 1028 1029 if (!Caller->use_empty()) 1030 Caller->replaceAllUsesWith(NV); 1031 1032 EraseInstFromFunction(*Caller); 1033 return true; 1034} 1035 1036// transformCallThroughTrampoline - Turn a call to a function created by the 1037// init_trampoline intrinsic into a direct call to the underlying function. 1038// 1039Instruction *InstCombiner::transformCallThroughTrampoline(CallSite CS) { 1040 Value *Callee = CS.getCalledValue(); 1041 const PointerType *PTy = cast<PointerType>(Callee->getType()); 1042 const FunctionType *FTy = cast<FunctionType>(PTy->getElementType()); 1043 const AttrListPtr &Attrs = CS.getAttributes(); 1044 1045 // If the call already has the 'nest' attribute somewhere then give up - 1046 // otherwise 'nest' would occur twice after splicing in the chain. 1047 if (Attrs.hasAttrSomewhere(Attribute::Nest)) 1048 return 0; 1049 1050 IntrinsicInst *Tramp = 1051 cast<IntrinsicInst>(cast<BitCastInst>(Callee)->getOperand(0)); 1052 1053 Function *NestF = cast<Function>(Tramp->getOperand(2)->stripPointerCasts()); 1054 const PointerType *NestFPTy = cast<PointerType>(NestF->getType()); 1055 const FunctionType *NestFTy = cast<FunctionType>(NestFPTy->getElementType()); 1056 1057 const AttrListPtr &NestAttrs = NestF->getAttributes(); 1058 if (!NestAttrs.isEmpty()) { 1059 unsigned NestIdx = 1; 1060 const Type *NestTy = 0; 1061 Attributes NestAttr = Attribute::None; 1062 1063 // Look for a parameter marked with the 'nest' attribute. 1064 for (FunctionType::param_iterator I = NestFTy->param_begin(), 1065 E = NestFTy->param_end(); I != E; ++NestIdx, ++I) 1066 if (NestAttrs.paramHasAttr(NestIdx, Attribute::Nest)) { 1067 // Record the parameter type and any other attributes. 1068 NestTy = *I; 1069 NestAttr = NestAttrs.getParamAttributes(NestIdx); 1070 break; 1071 } 1072 1073 if (NestTy) { 1074 Instruction *Caller = CS.getInstruction(); 1075 std::vector<Value*> NewArgs; 1076 NewArgs.reserve(unsigned(CS.arg_end()-CS.arg_begin())+1); 1077 1078 SmallVector<AttributeWithIndex, 8> NewAttrs; 1079 NewAttrs.reserve(Attrs.getNumSlots() + 1); 1080 1081 // Insert the nest argument into the call argument list, which may 1082 // mean appending it. Likewise for attributes. 1083 1084 // Add any result attributes. 1085 if (Attributes Attr = Attrs.getRetAttributes()) 1086 NewAttrs.push_back(AttributeWithIndex::get(0, Attr)); 1087 1088 { 1089 unsigned Idx = 1; 1090 CallSite::arg_iterator I = CS.arg_begin(), E = CS.arg_end(); 1091 do { 1092 if (Idx == NestIdx) { 1093 // Add the chain argument and attributes. 1094 Value *NestVal = Tramp->getOperand(3); 1095 if (NestVal->getType() != NestTy) 1096 NestVal = new BitCastInst(NestVal, NestTy, "nest", Caller); 1097 NewArgs.push_back(NestVal); 1098 NewAttrs.push_back(AttributeWithIndex::get(NestIdx, NestAttr)); 1099 } 1100 1101 if (I == E) 1102 break; 1103 1104 // Add the original argument and attributes. 1105 NewArgs.push_back(*I); 1106 if (Attributes Attr = Attrs.getParamAttributes(Idx)) 1107 NewAttrs.push_back 1108 (AttributeWithIndex::get(Idx + (Idx >= NestIdx), Attr)); 1109 1110 ++Idx, ++I; 1111 } while (1); 1112 } 1113 1114 // Add any function attributes. 1115 if (Attributes Attr = Attrs.getFnAttributes()) 1116 NewAttrs.push_back(AttributeWithIndex::get(~0, Attr)); 1117 1118 // The trampoline may have been bitcast to a bogus type (FTy). 1119 // Handle this by synthesizing a new function type, equal to FTy 1120 // with the chain parameter inserted. 1121 1122 std::vector<const Type*> NewTypes; 1123 NewTypes.reserve(FTy->getNumParams()+1); 1124 1125 // Insert the chain's type into the list of parameter types, which may 1126 // mean appending it. 1127 { 1128 unsigned Idx = 1; 1129 FunctionType::param_iterator I = FTy->param_begin(), 1130 E = FTy->param_end(); 1131 1132 do { 1133 if (Idx == NestIdx) 1134 // Add the chain's type. 1135 NewTypes.push_back(NestTy); 1136 1137 if (I == E) 1138 break; 1139 1140 // Add the original type. 1141 NewTypes.push_back(*I); 1142 1143 ++Idx, ++I; 1144 } while (1); 1145 } 1146 1147 // Replace the trampoline call with a direct call. Let the generic 1148 // code sort out any function type mismatches. 1149 FunctionType *NewFTy = FunctionType::get(FTy->getReturnType(), NewTypes, 1150 FTy->isVarArg()); 1151 Constant *NewCallee = 1152 NestF->getType() == PointerType::getUnqual(NewFTy) ? 1153 NestF : ConstantExpr::getBitCast(NestF, 1154 PointerType::getUnqual(NewFTy)); 1155 const AttrListPtr &NewPAL = AttrListPtr::get(NewAttrs.begin(), 1156 NewAttrs.end()); 1157 1158 Instruction *NewCaller; 1159 if (InvokeInst *II = dyn_cast<InvokeInst>(Caller)) { 1160 NewCaller = InvokeInst::Create(NewCallee, 1161 II->getNormalDest(), II->getUnwindDest(), 1162 NewArgs.begin(), NewArgs.end(), 1163 Caller->getName(), Caller); 1164 cast<InvokeInst>(NewCaller)->setCallingConv(II->getCallingConv()); 1165 cast<InvokeInst>(NewCaller)->setAttributes(NewPAL); 1166 } else { 1167 NewCaller = CallInst::Create(NewCallee, NewArgs.begin(), NewArgs.end(), 1168 Caller->getName(), Caller); 1169 if (cast<CallInst>(Caller)->isTailCall()) 1170 cast<CallInst>(NewCaller)->setTailCall(); 1171 cast<CallInst>(NewCaller)-> 1172 setCallingConv(cast<CallInst>(Caller)->getCallingConv()); 1173 cast<CallInst>(NewCaller)->setAttributes(NewPAL); 1174 } 1175 if (!Caller->getType()->isVoidTy()) 1176 Caller->replaceAllUsesWith(NewCaller); 1177 Caller->eraseFromParent(); 1178 Worklist.Remove(Caller); 1179 return 0; 1180 } 1181 } 1182 1183 // Replace the trampoline call with a direct call. Since there is no 'nest' 1184 // parameter, there is no need to adjust the argument list. Let the generic 1185 // code sort out any function type mismatches. 1186 Constant *NewCallee = 1187 NestF->getType() == PTy ? NestF : 1188 ConstantExpr::getBitCast(NestF, PTy); 1189 CS.setCalledFunction(NewCallee); 1190 return CS.getInstruction(); 1191} 1192 1193