1 //===- MemoryLocation.cpp - Memory location descriptions -------------------==// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #include "llvm/Analysis/MemoryLocation.h" 10 #include "llvm/Analysis/TargetLibraryInfo.h" 11 #include "llvm/IR/BasicBlock.h" 12 #include "llvm/IR/DataLayout.h" 13 #include "llvm/IR/Instructions.h" 14 #include "llvm/IR/IntrinsicInst.h" 15 #include "llvm/IR/IntrinsicsARM.h" 16 #include "llvm/IR/LLVMContext.h" 17 #include "llvm/IR/Module.h" 18 #include "llvm/IR/Type.h" 19 using namespace llvm; 20 21 void LocationSize::print(raw_ostream &OS) const { 22 OS << "LocationSize::"; 23 if (*this == unknown()) 24 OS << "unknown"; 25 else if (*this == mapEmpty()) 26 OS << "mapEmpty"; 27 else if (*this == mapTombstone()) 28 OS << "mapTombstone"; 29 else if (isPrecise()) 30 OS << "precise(" << getValue() << ')'; 31 else 32 OS << "upperBound(" << getValue() << ')'; 33 } 34 35 MemoryLocation MemoryLocation::get(const LoadInst *LI) { 36 AAMDNodes AATags; 37 LI->getAAMetadata(AATags); 38 const auto &DL = LI->getModule()->getDataLayout(); 39 40 return MemoryLocation( 41 LI->getPointerOperand(), 42 LocationSize::precise(DL.getTypeStoreSize(LI->getType())), AATags); 43 } 44 45 MemoryLocation MemoryLocation::get(const StoreInst *SI) { 46 AAMDNodes AATags; 47 SI->getAAMetadata(AATags); 48 const auto &DL = SI->getModule()->getDataLayout(); 49 50 return MemoryLocation(SI->getPointerOperand(), 51 LocationSize::precise(DL.getTypeStoreSize( 52 SI->getValueOperand()->getType())), 53 AATags); 54 } 55 56 MemoryLocation MemoryLocation::get(const VAArgInst *VI) { 57 AAMDNodes AATags; 58 VI->getAAMetadata(AATags); 59 60 return MemoryLocation(VI->getPointerOperand(), LocationSize::unknown(), 61 AATags); 62 } 63 64 MemoryLocation MemoryLocation::get(const AtomicCmpXchgInst *CXI) { 65 AAMDNodes AATags; 66 CXI->getAAMetadata(AATags); 67 const auto &DL = CXI->getModule()->getDataLayout(); 68 69 return MemoryLocation(CXI->getPointerOperand(), 70 LocationSize::precise(DL.getTypeStoreSize( 71 CXI->getCompareOperand()->getType())), 72 AATags); 73 } 74 75 MemoryLocation MemoryLocation::get(const AtomicRMWInst *RMWI) { 76 AAMDNodes AATags; 77 RMWI->getAAMetadata(AATags); 78 const auto &DL = RMWI->getModule()->getDataLayout(); 79 80 return MemoryLocation(RMWI->getPointerOperand(), 81 LocationSize::precise(DL.getTypeStoreSize( 82 RMWI->getValOperand()->getType())), 83 AATags); 84 } 85 86 MemoryLocation MemoryLocation::getForSource(const MemTransferInst *MTI) { 87 return getForSource(cast<AnyMemTransferInst>(MTI)); 88 } 89 90 MemoryLocation MemoryLocation::getForSource(const AtomicMemTransferInst *MTI) { 91 return getForSource(cast<AnyMemTransferInst>(MTI)); 92 } 93 94 MemoryLocation MemoryLocation::getForSource(const AnyMemTransferInst *MTI) { 95 auto Size = LocationSize::unknown(); 96 if (ConstantInt *C = dyn_cast<ConstantInt>(MTI->getLength())) 97 Size = LocationSize::precise(C->getValue().getZExtValue()); 98 99 // memcpy/memmove can have AA tags. For memcpy, they apply 100 // to both the source and the destination. 101 AAMDNodes AATags; 102 MTI->getAAMetadata(AATags); 103 104 return MemoryLocation(MTI->getRawSource(), Size, AATags); 105 } 106 107 MemoryLocation MemoryLocation::getForDest(const MemIntrinsic *MI) { 108 return getForDest(cast<AnyMemIntrinsic>(MI)); 109 } 110 111 MemoryLocation MemoryLocation::getForDest(const AtomicMemIntrinsic *MI) { 112 return getForDest(cast<AnyMemIntrinsic>(MI)); 113 } 114 115 MemoryLocation MemoryLocation::getForDest(const AnyMemIntrinsic *MI) { 116 auto Size = LocationSize::unknown(); 117 if (ConstantInt *C = dyn_cast<ConstantInt>(MI->getLength())) 118 Size = LocationSize::precise(C->getValue().getZExtValue()); 119 120 // memcpy/memmove can have AA tags. For memcpy, they apply 121 // to both the source and the destination. 122 AAMDNodes AATags; 123 MI->getAAMetadata(AATags); 124 125 return MemoryLocation(MI->getRawDest(), Size, AATags); 126 } 127 128 MemoryLocation MemoryLocation::getForArgument(const CallBase *Call, 129 unsigned ArgIdx, 130 const TargetLibraryInfo *TLI) { 131 AAMDNodes AATags; 132 Call->getAAMetadata(AATags); 133 const Value *Arg = Call->getArgOperand(ArgIdx); 134 135 // We may be able to produce an exact size for known intrinsics. 136 if (const IntrinsicInst *II = dyn_cast<IntrinsicInst>(Call)) { 137 const DataLayout &DL = II->getModule()->getDataLayout(); 138 139 switch (II->getIntrinsicID()) { 140 default: 141 break; 142 case Intrinsic::memset: 143 case Intrinsic::memcpy: 144 case Intrinsic::memmove: 145 assert((ArgIdx == 0 || ArgIdx == 1) && 146 "Invalid argument index for memory intrinsic"); 147 if (ConstantInt *LenCI = dyn_cast<ConstantInt>(II->getArgOperand(2))) 148 return MemoryLocation(Arg, LocationSize::precise(LenCI->getZExtValue()), 149 AATags); 150 break; 151 152 case Intrinsic::lifetime_start: 153 case Intrinsic::lifetime_end: 154 case Intrinsic::invariant_start: 155 assert(ArgIdx == 1 && "Invalid argument index"); 156 return MemoryLocation( 157 Arg, 158 LocationSize::precise( 159 cast<ConstantInt>(II->getArgOperand(0))->getZExtValue()), 160 AATags); 161 162 case Intrinsic::invariant_end: 163 // The first argument to an invariant.end is a "descriptor" type (e.g. a 164 // pointer to a empty struct) which is never actually dereferenced. 165 if (ArgIdx == 0) 166 return MemoryLocation(Arg, LocationSize::precise(0), AATags); 167 assert(ArgIdx == 2 && "Invalid argument index"); 168 return MemoryLocation( 169 Arg, 170 LocationSize::precise( 171 cast<ConstantInt>(II->getArgOperand(1))->getZExtValue()), 172 AATags); 173 174 case Intrinsic::arm_neon_vld1: 175 assert(ArgIdx == 0 && "Invalid argument index"); 176 // LLVM's vld1 and vst1 intrinsics currently only support a single 177 // vector register. 178 return MemoryLocation( 179 Arg, LocationSize::precise(DL.getTypeStoreSize(II->getType())), 180 AATags); 181 182 case Intrinsic::arm_neon_vst1: 183 assert(ArgIdx == 0 && "Invalid argument index"); 184 return MemoryLocation(Arg, 185 LocationSize::precise(DL.getTypeStoreSize( 186 II->getArgOperand(1)->getType())), 187 AATags); 188 } 189 } 190 191 // We can bound the aliasing properties of memset_pattern16 just as we can 192 // for memcpy/memset. This is particularly important because the 193 // LoopIdiomRecognizer likes to turn loops into calls to memset_pattern16 194 // whenever possible. 195 LibFunc F; 196 if (TLI && Call->getCalledFunction() && 197 TLI->getLibFunc(*Call->getCalledFunction(), F) && 198 F == LibFunc_memset_pattern16 && TLI->has(F)) { 199 assert((ArgIdx == 0 || ArgIdx == 1) && 200 "Invalid argument index for memset_pattern16"); 201 if (ArgIdx == 1) 202 return MemoryLocation(Arg, LocationSize::precise(16), AATags); 203 if (const ConstantInt *LenCI = 204 dyn_cast<ConstantInt>(Call->getArgOperand(2))) 205 return MemoryLocation(Arg, LocationSize::precise(LenCI->getZExtValue()), 206 AATags); 207 } 208 // FIXME: Handle memset_pattern4 and memset_pattern8 also. 209 210 return MemoryLocation(Call->getArgOperand(ArgIdx), LocationSize::unknown(), 211 AATags); 212 } 213