Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 1 | //===- MemoryDependenceAnalysis.cpp - Mem Deps Implementation --*- C++ -*-===// |
| 2 | // |
| 3 | // The LLVM Compiler Infrastructure |
| 4 | // |
| 5 | // This file was developed by the Owen Anderson and is distributed under |
| 6 | // the University of Illinois Open Source License. See LICENSE.TXT for details. |
| 7 | // |
| 8 | //===----------------------------------------------------------------------===// |
| 9 | // |
| 10 | // This file implements an analysis that determines, for a given memory |
| 11 | // operation, what preceding memory operations it depends on. It builds on |
Owen Anderson | 80b1f09 | 2007-08-08 22:01:54 +0000 | [diff] [blame^] | 12 | // alias analysis information, and tries to provide a lazy, caching interface to |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 13 | // a common kind of alias information query. |
| 14 | // |
| 15 | //===----------------------------------------------------------------------===// |
| 16 | |
| 17 | #include "llvm/Analysis/MemoryDependenceAnalysis.h" |
Owen Anderson | 7a616a1 | 2007-07-10 17:25:03 +0000 | [diff] [blame] | 18 | #include "llvm/Constants.h" |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 19 | #include "llvm/Instructions.h" |
| 20 | #include "llvm/Function.h" |
| 21 | #include "llvm/Analysis/AliasAnalysis.h" |
Owen Anderson | 4beedbd | 2007-07-24 21:52:37 +0000 | [diff] [blame] | 22 | #include "llvm/Support/CFG.h" |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 23 | #include "llvm/Target/TargetData.h" |
| 24 | |
| 25 | using namespace llvm; |
| 26 | |
| 27 | char MemoryDependenceAnalysis::ID = 0; |
| 28 | |
Owen Anderson | 8cad423 | 2007-08-08 21:39:39 +0000 | [diff] [blame] | 29 | const Instruction* MemoryDependenceAnalysis::NonLocal = (Instruction*)-3; |
| 30 | const Instruction* MemoryDependenceAnalysis::None = (Instruction*)-4; |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 31 | |
| 32 | // Register this pass... |
Owen Anderson | 776ee1f | 2007-07-10 20:21:08 +0000 | [diff] [blame] | 33 | static RegisterPass<MemoryDependenceAnalysis> X("memdep", |
| 34 | "Memory Dependence Analysis"); |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 35 | |
| 36 | /// getAnalysisUsage - Does not modify anything. It uses Alias Analysis. |
| 37 | /// |
| 38 | void MemoryDependenceAnalysis::getAnalysisUsage(AnalysisUsage &AU) const { |
| 39 | AU.setPreservesAll(); |
| 40 | AU.addRequiredTransitive<AliasAnalysis>(); |
| 41 | AU.addRequiredTransitive<TargetData>(); |
| 42 | } |
| 43 | |
Owen Anderson | 5f32320 | 2007-07-10 17:59:22 +0000 | [diff] [blame] | 44 | // Find the dependency of a CallSite |
Owen Anderson | 80b1f09 | 2007-08-08 22:01:54 +0000 | [diff] [blame^] | 45 | const Instruction* MemoryDependenceAnalysis::getCallSiteDependency(CallSite C, |
| 46 | Instruction* start, |
| 47 | BasicBlock* block) { |
Owen Anderson | 5f32320 | 2007-07-10 17:59:22 +0000 | [diff] [blame] | 48 | |
| 49 | AliasAnalysis& AA = getAnalysis<AliasAnalysis>(); |
| 50 | TargetData& TD = getAnalysis<TargetData>(); |
| 51 | BasicBlock::iterator blockBegin = C.getInstruction()->getParent()->begin(); |
| 52 | BasicBlock::iterator QI = C.getInstruction(); |
| 53 | |
Owen Anderson | dbbe816 | 2007-08-07 00:33:45 +0000 | [diff] [blame] | 54 | if (start) { |
| 55 | QI = start; |
| 56 | blockBegin = start->getParent()->end(); |
| 57 | } else if (!start && block) { |
| 58 | QI = block->end(); |
| 59 | blockBegin = block->end(); |
| 60 | } |
| 61 | |
Owen Anderson | 5f32320 | 2007-07-10 17:59:22 +0000 | [diff] [blame] | 62 | while (QI != blockBegin) { |
| 63 | --QI; |
| 64 | |
| 65 | // If this inst is a memory op, get the pointer it accessed |
| 66 | Value* pointer = 0; |
| 67 | uint64_t pointerSize = 0; |
| 68 | if (StoreInst* S = dyn_cast<StoreInst>(QI)) { |
| 69 | pointer = S->getPointerOperand(); |
| 70 | pointerSize = TD.getTypeSize(S->getOperand(0)->getType()); |
| 71 | } else if (LoadInst* L = dyn_cast<LoadInst>(QI)) { |
| 72 | pointer = L->getPointerOperand(); |
| 73 | pointerSize = TD.getTypeSize(L->getType()); |
| 74 | } else if (AllocationInst* AI = dyn_cast<AllocationInst>(QI)) { |
| 75 | pointer = AI; |
| 76 | if (ConstantInt* C = dyn_cast<ConstantInt>(AI->getArraySize())) |
Owen Anderson | 80b1f09 | 2007-08-08 22:01:54 +0000 | [diff] [blame^] | 77 | pointerSize = C->getZExtValue() * \ |
| 78 | TD.getTypeSize(AI->getAllocatedType()); |
Owen Anderson | 5f32320 | 2007-07-10 17:59:22 +0000 | [diff] [blame] | 79 | else |
| 80 | pointerSize = ~0UL; |
Owen Anderson | 06b6e82 | 2007-07-10 18:43:15 +0000 | [diff] [blame] | 81 | } else if (VAArgInst* V = dyn_cast<VAArgInst>(QI)) { |
| 82 | pointer = V->getOperand(0); |
| 83 | pointerSize = TD.getTypeSize(V->getType()); |
Owen Anderson | 5f32320 | 2007-07-10 17:59:22 +0000 | [diff] [blame] | 84 | } else if (FreeInst* F = dyn_cast<FreeInst>(QI)) { |
| 85 | pointer = F->getPointerOperand(); |
| 86 | |
| 87 | // FreeInsts erase the entire structure |
| 88 | pointerSize = ~0UL; |
| 89 | } else if (CallSite::get(QI).getInstruction() != 0) { |
| 90 | if (AA.getModRefInfo(C, CallSite::get(QI)) != AliasAnalysis::NoModRef) { |
Owen Anderson | dbbe816 | 2007-08-07 00:33:45 +0000 | [diff] [blame] | 91 | if (!start && !block) { |
| 92 | depGraphLocal.insert(std::make_pair(C.getInstruction(), |
| 93 | std::make_pair(QI, true))); |
| 94 | reverseDep[QI].insert(C.getInstruction()); |
| 95 | } |
Owen Anderson | 5f32320 | 2007-07-10 17:59:22 +0000 | [diff] [blame] | 96 | return QI; |
| 97 | } else { |
| 98 | continue; |
| 99 | } |
Owen Anderson | 202da14 | 2007-07-10 20:39:07 +0000 | [diff] [blame] | 100 | } else |
| 101 | continue; |
Owen Anderson | 5f32320 | 2007-07-10 17:59:22 +0000 | [diff] [blame] | 102 | |
| 103 | if (AA.getModRefInfo(C, pointer, pointerSize) != AliasAnalysis::NoModRef) { |
Owen Anderson | dbbe816 | 2007-08-07 00:33:45 +0000 | [diff] [blame] | 104 | if (!start && !block) { |
| 105 | depGraphLocal.insert(std::make_pair(C.getInstruction(), |
| 106 | std::make_pair(QI, true))); |
| 107 | reverseDep[QI].insert(C.getInstruction()); |
| 108 | } |
Owen Anderson | 5f32320 | 2007-07-10 17:59:22 +0000 | [diff] [blame] | 109 | return QI; |
| 110 | } |
| 111 | } |
| 112 | |
| 113 | // No dependence found |
Owen Anderson | 80b1f09 | 2007-08-08 22:01:54 +0000 | [diff] [blame^] | 114 | depGraphLocal.insert(std::make_pair(C.getInstruction(), |
| 115 | std::make_pair(NonLocal, true))); |
Owen Anderson | dbbe816 | 2007-08-07 00:33:45 +0000 | [diff] [blame] | 116 | reverseDep[NonLocal].insert(C.getInstruction()); |
Owen Anderson | 5f32320 | 2007-07-10 17:59:22 +0000 | [diff] [blame] | 117 | return NonLocal; |
| 118 | } |
| 119 | |
Owen Anderson | 9066020 | 2007-08-01 22:01:54 +0000 | [diff] [blame] | 120 | void MemoryDependenceAnalysis::nonLocalHelper(Instruction* query, |
Owen Anderson | 0cd3203 | 2007-07-25 19:57:03 +0000 | [diff] [blame] | 121 | BasicBlock* block, |
Owen Anderson | 80b1f09 | 2007-08-08 22:01:54 +0000 | [diff] [blame^] | 122 | DenseMap<BasicBlock*, Value*>& resp) { |
Owen Anderson | 9066020 | 2007-08-01 22:01:54 +0000 | [diff] [blame] | 123 | SmallPtrSet<BasicBlock*, 4> visited; |
| 124 | SmallVector<BasicBlock*, 4> stack; |
| 125 | stack.push_back(block); |
Owen Anderson | 4beedbd | 2007-07-24 21:52:37 +0000 | [diff] [blame] | 126 | |
Owen Anderson | 9066020 | 2007-08-01 22:01:54 +0000 | [diff] [blame] | 127 | while (!stack.empty()) { |
| 128 | BasicBlock* BB = stack.back(); |
| 129 | |
Owen Anderson | 1c2763d | 2007-08-02 17:56:05 +0000 | [diff] [blame] | 130 | if (visited.count(BB)) { |
Owen Anderson | 9066020 | 2007-08-01 22:01:54 +0000 | [diff] [blame] | 131 | stack.pop_back(); |
| 132 | continue; |
| 133 | } |
| 134 | |
| 135 | if (BB != block) { |
Owen Anderson | 1c2763d | 2007-08-02 17:56:05 +0000 | [diff] [blame] | 136 | visited.insert(BB); |
| 137 | |
Owen Anderson | 8cad423 | 2007-08-08 21:39:39 +0000 | [diff] [blame] | 138 | const Instruction* localDep = getDependency(query, 0, BB); |
Owen Anderson | 9066020 | 2007-08-01 22:01:54 +0000 | [diff] [blame] | 139 | if (localDep != NonLocal) { |
Owen Anderson | 8cad423 | 2007-08-08 21:39:39 +0000 | [diff] [blame] | 140 | resp.insert(std::make_pair(BB, const_cast<Instruction*>(localDep))); |
Owen Anderson | 1c2763d | 2007-08-02 17:56:05 +0000 | [diff] [blame] | 141 | stack.pop_back(); |
| 142 | |
Owen Anderson | 9066020 | 2007-08-01 22:01:54 +0000 | [diff] [blame] | 143 | continue; |
| 144 | } |
Owen Anderson | 1c2763d | 2007-08-02 17:56:05 +0000 | [diff] [blame] | 145 | } else if (BB == block && stack.size() > 1) { |
| 146 | visited.insert(BB); |
| 147 | |
Owen Anderson | 8cad423 | 2007-08-08 21:39:39 +0000 | [diff] [blame] | 148 | const Instruction* localDep = getDependency(query, 0, BB); |
Owen Anderson | 1c2763d | 2007-08-02 17:56:05 +0000 | [diff] [blame] | 149 | if (localDep != query) |
Owen Anderson | 8cad423 | 2007-08-08 21:39:39 +0000 | [diff] [blame] | 150 | resp.insert(std::make_pair(BB, const_cast<Instruction*>(localDep))); |
Owen Anderson | 1c2763d | 2007-08-02 17:56:05 +0000 | [diff] [blame] | 151 | |
| 152 | stack.pop_back(); |
| 153 | |
| 154 | continue; |
Owen Anderson | 9066020 | 2007-08-01 22:01:54 +0000 | [diff] [blame] | 155 | } |
| 156 | |
| 157 | bool predOnStack = false; |
| 158 | bool inserted = false; |
| 159 | for (pred_iterator PI = pred_begin(BB), PE = pred_end(BB); |
| 160 | PI != PE; ++PI) |
| 161 | if (!visited.count(*PI)) { |
| 162 | stack.push_back(*PI); |
| 163 | inserted = true; |
| 164 | } else |
| 165 | predOnStack = true; |
| 166 | |
| 167 | if (inserted) |
| 168 | continue; |
| 169 | else if (!inserted && !predOnStack) { |
Owen Anderson | 8cad423 | 2007-08-08 21:39:39 +0000 | [diff] [blame] | 170 | resp.insert(std::make_pair(BB, const_cast<Instruction*>(None))); |
Owen Anderson | 9066020 | 2007-08-01 22:01:54 +0000 | [diff] [blame] | 171 | } else if (!inserted && predOnStack){ |
Owen Anderson | 8cad423 | 2007-08-08 21:39:39 +0000 | [diff] [blame] | 172 | resp.insert(std::make_pair(BB, const_cast<Instruction*>(NonLocal))); |
Owen Anderson | 9066020 | 2007-08-01 22:01:54 +0000 | [diff] [blame] | 173 | } |
| 174 | |
| 175 | stack.pop_back(); |
Owen Anderson | 4beedbd | 2007-07-24 21:52:37 +0000 | [diff] [blame] | 176 | } |
Owen Anderson | 4beedbd | 2007-07-24 21:52:37 +0000 | [diff] [blame] | 177 | } |
| 178 | |
Owen Anderson | 80b1f09 | 2007-08-08 22:01:54 +0000 | [diff] [blame^] | 179 | /// getNonLocalDependency - Fills the passed-in map with the non-local |
| 180 | /// dependencies of the queries. The map will contain NonLocal for |
| 181 | /// blocks between the query and its dependencies. |
Owen Anderson | 9066020 | 2007-08-01 22:01:54 +0000 | [diff] [blame] | 182 | void MemoryDependenceAnalysis::getNonLocalDependency(Instruction* query, |
Owen Anderson | 80b1f09 | 2007-08-08 22:01:54 +0000 | [diff] [blame^] | 183 | DenseMap<BasicBlock*, Value*>& resp) { |
Owen Anderson | 8cad423 | 2007-08-08 21:39:39 +0000 | [diff] [blame] | 184 | const Instruction* localDep = getDependency(query); |
Owen Anderson | 4beedbd | 2007-07-24 21:52:37 +0000 | [diff] [blame] | 185 | if (localDep != NonLocal) { |
Owen Anderson | 80b1f09 | 2007-08-08 22:01:54 +0000 | [diff] [blame^] | 186 | resp.insert(std::make_pair(query->getParent(), |
| 187 | const_cast<Instruction*>(localDep))); |
Owen Anderson | 9066020 | 2007-08-01 22:01:54 +0000 | [diff] [blame] | 188 | return; |
Owen Anderson | 4beedbd | 2007-07-24 21:52:37 +0000 | [diff] [blame] | 189 | } |
| 190 | |
Owen Anderson | 9066020 | 2007-08-01 22:01:54 +0000 | [diff] [blame] | 191 | nonLocalHelper(query, query->getParent(), resp); |
Owen Anderson | 4beedbd | 2007-07-24 21:52:37 +0000 | [diff] [blame] | 192 | } |
| 193 | |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 194 | /// getDependency - Return the instruction on which a memory operation |
Owen Anderson | 6b278fc | 2007-07-10 17:08:11 +0000 | [diff] [blame] | 195 | /// depends. The local paramter indicates if the query should only |
| 196 | /// evaluate dependencies within the same basic block. |
Owen Anderson | 8cad423 | 2007-08-08 21:39:39 +0000 | [diff] [blame] | 197 | const Instruction* MemoryDependenceAnalysis::getDependency(Instruction* query, |
Owen Anderson | faac518 | 2007-07-16 21:52:50 +0000 | [diff] [blame] | 198 | Instruction* start, |
Owen Anderson | 4beedbd | 2007-07-24 21:52:37 +0000 | [diff] [blame] | 199 | BasicBlock* block) { |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 200 | // Start looking for dependencies with the queried inst |
| 201 | BasicBlock::iterator QI = query; |
| 202 | |
| 203 | // Check for a cached result |
Owen Anderson | 8cad423 | 2007-08-08 21:39:39 +0000 | [diff] [blame] | 204 | std::pair<const Instruction*, bool> cachedResult = depGraphLocal[query]; |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 205 | // If we have a _confirmed_ cached entry, return it |
| 206 | if (cachedResult.second) |
| 207 | return cachedResult.first; |
Owen Anderson | 0cd3203 | 2007-07-25 19:57:03 +0000 | [diff] [blame] | 208 | else if (cachedResult.first && cachedResult.first != NonLocal) |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 209 | // If we have an unconfirmed cached entry, we can start our search from there |
Owen Anderson | 8cad423 | 2007-08-08 21:39:39 +0000 | [diff] [blame] | 210 | QI = const_cast<Instruction*>(cachedResult.first); |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 211 | |
Owen Anderson | faac518 | 2007-07-16 21:52:50 +0000 | [diff] [blame] | 212 | if (start) |
| 213 | QI = start; |
Owen Anderson | 0cd3203 | 2007-07-25 19:57:03 +0000 | [diff] [blame] | 214 | else if (!start && block) |
| 215 | QI = block->end(); |
Owen Anderson | faac518 | 2007-07-16 21:52:50 +0000 | [diff] [blame] | 216 | |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 217 | AliasAnalysis& AA = getAnalysis<AliasAnalysis>(); |
Owen Anderson | 6b278fc | 2007-07-10 17:08:11 +0000 | [diff] [blame] | 218 | TargetData& TD = getAnalysis<TargetData>(); |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 219 | |
| 220 | // Get the pointer value for which dependence will be determined |
| 221 | Value* dependee = 0; |
Owen Anderson | 6b278fc | 2007-07-10 17:08:11 +0000 | [diff] [blame] | 222 | uint64_t dependeeSize = 0; |
Owen Anderson | e314eb3 | 2007-07-10 18:11:42 +0000 | [diff] [blame] | 223 | bool queryIsVolatile = false; |
Owen Anderson | faac518 | 2007-07-16 21:52:50 +0000 | [diff] [blame] | 224 | if (StoreInst* S = dyn_cast<StoreInst>(query)) { |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 225 | dependee = S->getPointerOperand(); |
Owen Anderson | 7a616a1 | 2007-07-10 17:25:03 +0000 | [diff] [blame] | 226 | dependeeSize = TD.getTypeSize(S->getOperand(0)->getType()); |
Owen Anderson | e314eb3 | 2007-07-10 18:11:42 +0000 | [diff] [blame] | 227 | queryIsVolatile = S->isVolatile(); |
Owen Anderson | faac518 | 2007-07-16 21:52:50 +0000 | [diff] [blame] | 228 | } else if (LoadInst* L = dyn_cast<LoadInst>(query)) { |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 229 | dependee = L->getPointerOperand(); |
Owen Anderson | 7a616a1 | 2007-07-10 17:25:03 +0000 | [diff] [blame] | 230 | dependeeSize = TD.getTypeSize(L->getType()); |
Owen Anderson | e314eb3 | 2007-07-10 18:11:42 +0000 | [diff] [blame] | 231 | queryIsVolatile = L->isVolatile(); |
Owen Anderson | faac518 | 2007-07-16 21:52:50 +0000 | [diff] [blame] | 232 | } else if (VAArgInst* V = dyn_cast<VAArgInst>(query)) { |
Owen Anderson | 06b6e82 | 2007-07-10 18:43:15 +0000 | [diff] [blame] | 233 | dependee = V->getOperand(0); |
| 234 | dependeeSize = TD.getTypeSize(V->getType()); |
Owen Anderson | faac518 | 2007-07-16 21:52:50 +0000 | [diff] [blame] | 235 | } else if (FreeInst* F = dyn_cast<FreeInst>(query)) { |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 236 | dependee = F->getPointerOperand(); |
Owen Anderson | 6b278fc | 2007-07-10 17:08:11 +0000 | [diff] [blame] | 237 | |
| 238 | // FreeInsts erase the entire structure, not just a field |
| 239 | dependeeSize = ~0UL; |
Owen Anderson | faac518 | 2007-07-16 21:52:50 +0000 | [diff] [blame] | 240 | } else if (CallSite::get(query).getInstruction() != 0) |
Owen Anderson | dbbe816 | 2007-08-07 00:33:45 +0000 | [diff] [blame] | 241 | return getCallSiteDependency(CallSite::get(query), start, block); |
Owen Anderson | 5f32320 | 2007-07-10 17:59:22 +0000 | [diff] [blame] | 242 | else if (isa<AllocationInst>(query)) |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 243 | return None; |
Owen Anderson | 7a616a1 | 2007-07-10 17:25:03 +0000 | [diff] [blame] | 244 | else |
Owen Anderson | 6b278fc | 2007-07-10 17:08:11 +0000 | [diff] [blame] | 245 | return None; |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 246 | |
Owen Anderson | 4beedbd | 2007-07-24 21:52:37 +0000 | [diff] [blame] | 247 | BasicBlock::iterator blockBegin = block ? block->begin() |
| 248 | : query->getParent()->begin(); |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 249 | |
| 250 | while (QI != blockBegin) { |
Owen Anderson | 6b278fc | 2007-07-10 17:08:11 +0000 | [diff] [blame] | 251 | --QI; |
| 252 | |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 253 | // If this inst is a memory op, get the pointer it accessed |
| 254 | Value* pointer = 0; |
Owen Anderson | 6b278fc | 2007-07-10 17:08:11 +0000 | [diff] [blame] | 255 | uint64_t pointerSize = 0; |
| 256 | if (StoreInst* S = dyn_cast<StoreInst>(QI)) { |
Owen Anderson | e314eb3 | 2007-07-10 18:11:42 +0000 | [diff] [blame] | 257 | // All volatile loads/stores depend on each other |
| 258 | if (queryIsVolatile && S->isVolatile()) { |
Owen Anderson | dbbe816 | 2007-08-07 00:33:45 +0000 | [diff] [blame] | 259 | if (!start && !block) { |
Owen Anderson | faac518 | 2007-07-16 21:52:50 +0000 | [diff] [blame] | 260 | depGraphLocal.insert(std::make_pair(query, std::make_pair(S, true))); |
Owen Anderson | dbbe816 | 2007-08-07 00:33:45 +0000 | [diff] [blame] | 261 | reverseDep[S].insert(query); |
Owen Anderson | faac518 | 2007-07-16 21:52:50 +0000 | [diff] [blame] | 262 | } |
| 263 | |
Owen Anderson | e314eb3 | 2007-07-10 18:11:42 +0000 | [diff] [blame] | 264 | return S; |
| 265 | } |
| 266 | |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 267 | pointer = S->getPointerOperand(); |
Owen Anderson | 7a616a1 | 2007-07-10 17:25:03 +0000 | [diff] [blame] | 268 | pointerSize = TD.getTypeSize(S->getOperand(0)->getType()); |
Owen Anderson | 6b278fc | 2007-07-10 17:08:11 +0000 | [diff] [blame] | 269 | } else if (LoadInst* L = dyn_cast<LoadInst>(QI)) { |
Owen Anderson | e314eb3 | 2007-07-10 18:11:42 +0000 | [diff] [blame] | 270 | // All volatile loads/stores depend on each other |
| 271 | if (queryIsVolatile && L->isVolatile()) { |
Owen Anderson | dbbe816 | 2007-08-07 00:33:45 +0000 | [diff] [blame] | 272 | if (!start && !block) { |
Owen Anderson | faac518 | 2007-07-16 21:52:50 +0000 | [diff] [blame] | 273 | depGraphLocal.insert(std::make_pair(query, std::make_pair(L, true))); |
Owen Anderson | dbbe816 | 2007-08-07 00:33:45 +0000 | [diff] [blame] | 274 | reverseDep[L].insert(query); |
Owen Anderson | faac518 | 2007-07-16 21:52:50 +0000 | [diff] [blame] | 275 | } |
| 276 | |
Owen Anderson | e314eb3 | 2007-07-10 18:11:42 +0000 | [diff] [blame] | 277 | return L; |
| 278 | } |
| 279 | |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 280 | pointer = L->getPointerOperand(); |
Owen Anderson | 7a616a1 | 2007-07-10 17:25:03 +0000 | [diff] [blame] | 281 | pointerSize = TD.getTypeSize(L->getType()); |
Owen Anderson | 6b278fc | 2007-07-10 17:08:11 +0000 | [diff] [blame] | 282 | } else if (AllocationInst* AI = dyn_cast<AllocationInst>(QI)) { |
| 283 | pointer = AI; |
Owen Anderson | 7a616a1 | 2007-07-10 17:25:03 +0000 | [diff] [blame] | 284 | if (ConstantInt* C = dyn_cast<ConstantInt>(AI->getArraySize())) |
Owen Anderson | 80b1f09 | 2007-08-08 22:01:54 +0000 | [diff] [blame^] | 285 | pointerSize = C->getZExtValue() * \ |
| 286 | TD.getTypeSize(AI->getAllocatedType()); |
Owen Anderson | 6b278fc | 2007-07-10 17:08:11 +0000 | [diff] [blame] | 287 | else |
| 288 | pointerSize = ~0UL; |
Owen Anderson | 06b6e82 | 2007-07-10 18:43:15 +0000 | [diff] [blame] | 289 | } else if (VAArgInst* V = dyn_cast<VAArgInst>(QI)) { |
| 290 | pointer = V->getOperand(0); |
| 291 | pointerSize = TD.getTypeSize(V->getType()); |
Owen Anderson | 6b278fc | 2007-07-10 17:08:11 +0000 | [diff] [blame] | 292 | } else if (FreeInst* F = dyn_cast<FreeInst>(QI)) { |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 293 | pointer = F->getPointerOperand(); |
Owen Anderson | 6b278fc | 2007-07-10 17:08:11 +0000 | [diff] [blame] | 294 | |
| 295 | // FreeInsts erase the entire structure |
| 296 | pointerSize = ~0UL; |
Owen Anderson | 5f32320 | 2007-07-10 17:59:22 +0000 | [diff] [blame] | 297 | } else if (CallSite::get(QI).getInstruction() != 0) { |
Owen Anderson | 80b1f09 | 2007-08-08 22:01:54 +0000 | [diff] [blame^] | 298 | // Call insts need special handling. Check if they can modify our pointer |
Owen Anderson | 8f35315 | 2007-08-06 23:26:03 +0000 | [diff] [blame] | 299 | AliasAnalysis::ModRefResult MR = AA.getModRefInfo(CallSite::get(QI), |
| 300 | dependee, dependeeSize); |
| 301 | |
| 302 | if (MR != AliasAnalysis::NoModRef) { |
| 303 | // Loads don't depend on read-only calls |
| 304 | if (isa<LoadInst>(query) && MR == AliasAnalysis::Ref) |
| 305 | continue; |
| 306 | |
Owen Anderson | dbbe816 | 2007-08-07 00:33:45 +0000 | [diff] [blame] | 307 | if (!start && !block) { |
Owen Anderson | 80b1f09 | 2007-08-08 22:01:54 +0000 | [diff] [blame^] | 308 | depGraphLocal.insert(std::make_pair(query, |
| 309 | std::make_pair(QI, true))); |
Owen Anderson | dbbe816 | 2007-08-07 00:33:45 +0000 | [diff] [blame] | 310 | reverseDep[QI].insert(query); |
Owen Anderson | faac518 | 2007-07-16 21:52:50 +0000 | [diff] [blame] | 311 | } |
| 312 | |
Owen Anderson | 5f32320 | 2007-07-10 17:59:22 +0000 | [diff] [blame] | 313 | return QI; |
Owen Anderson | 7a616a1 | 2007-07-10 17:25:03 +0000 | [diff] [blame] | 314 | } else { |
| 315 | continue; |
| 316 | } |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 317 | } |
| 318 | |
| 319 | // If we found a pointer, check if it could be the same as our pointer |
| 320 | if (pointer) { |
Owen Anderson | 6b278fc | 2007-07-10 17:08:11 +0000 | [diff] [blame] | 321 | AliasAnalysis::AliasResult R = AA.alias(pointer, pointerSize, |
| 322 | dependee, dependeeSize); |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 323 | |
| 324 | if (R != AliasAnalysis::NoAlias) { |
Owen Anderson | 8f35315 | 2007-08-06 23:26:03 +0000 | [diff] [blame] | 325 | // May-alias loads don't depend on each other |
| 326 | if (isa<LoadInst>(query) && isa<LoadInst>(QI) && |
| 327 | R == AliasAnalysis::MayAlias) |
| 328 | continue; |
| 329 | |
Owen Anderson | dbbe816 | 2007-08-07 00:33:45 +0000 | [diff] [blame] | 330 | if (!start && !block) { |
Owen Anderson | 80b1f09 | 2007-08-08 22:01:54 +0000 | [diff] [blame^] | 331 | depGraphLocal.insert(std::make_pair(query, |
| 332 | std::make_pair(QI, true))); |
Owen Anderson | dbbe816 | 2007-08-07 00:33:45 +0000 | [diff] [blame] | 333 | reverseDep[QI].insert(query); |
Owen Anderson | faac518 | 2007-07-16 21:52:50 +0000 | [diff] [blame] | 334 | } |
| 335 | |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 336 | return QI; |
| 337 | } |
| 338 | } |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 339 | } |
| 340 | |
| 341 | // If we found nothing, return the non-local flag |
Owen Anderson | dbbe816 | 2007-08-07 00:33:45 +0000 | [diff] [blame] | 342 | if (!start && !block) { |
Owen Anderson | faac518 | 2007-07-16 21:52:50 +0000 | [diff] [blame] | 343 | depGraphLocal.insert(std::make_pair(query, |
| 344 | std::make_pair(NonLocal, true))); |
Owen Anderson | dbbe816 | 2007-08-07 00:33:45 +0000 | [diff] [blame] | 345 | reverseDep[NonLocal].insert(query); |
Owen Anderson | faac518 | 2007-07-16 21:52:50 +0000 | [diff] [blame] | 346 | } |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 347 | |
| 348 | return NonLocal; |
| 349 | } |
| 350 | |
| 351 | /// removeInstruction - Remove an instruction from the dependence analysis, |
| 352 | /// updating the dependence of instructions that previously depended on it. |
| 353 | void MemoryDependenceAnalysis::removeInstruction(Instruction* rem) { |
| 354 | // Figure out the new dep for things that currently depend on rem |
Owen Anderson | 8cad423 | 2007-08-08 21:39:39 +0000 | [diff] [blame] | 355 | const Instruction* newDep = NonLocal; |
David Greene | df46419 | 2007-07-31 20:01:27 +0000 | [diff] [blame] | 356 | |
| 357 | depMapType::iterator depGraphEntry = depGraphLocal.find(rem); |
| 358 | // We assume here that it's not in the reverse map if it's not in |
| 359 | // the dep map. Checking it could be expensive, so don't do it. |
| 360 | |
| 361 | if (depGraphEntry != depGraphLocal.end()) { |
| 362 | if (depGraphEntry->second.first != NonLocal && |
| 363 | depGraphEntry->second.second) { |
| 364 | // If we have dep info for rem, set them to it |
Owen Anderson | 80b1f09 | 2007-08-08 22:01:54 +0000 | [diff] [blame^] | 365 | BasicBlock::iterator RI = |
| 366 | const_cast<Instruction*>(depGraphEntry->second.first); |
David Greene | df46419 | 2007-07-31 20:01:27 +0000 | [diff] [blame] | 367 | RI++; |
| 368 | newDep = RI; |
| 369 | } else if (depGraphEntry->second.first == NonLocal && |
| 370 | depGraphEntry->second.second ) { |
| 371 | // If we have a confirmed non-local flag, use it |
| 372 | newDep = NonLocal; |
| 373 | } else { |
| 374 | // Otherwise, use the immediate successor of rem |
Owen Anderson | 80b1f09 | 2007-08-08 22:01:54 +0000 | [diff] [blame^] | 375 | // NOTE: This is because, when getDependence is called, it will first |
| 376 | // check the immediate predecessor of what is in the cache. |
David Greene | df46419 | 2007-07-31 20:01:27 +0000 | [diff] [blame] | 377 | BasicBlock::iterator RI = rem; |
| 378 | RI++; |
| 379 | newDep = RI; |
| 380 | } |
| 381 | |
Owen Anderson | dbbe816 | 2007-08-07 00:33:45 +0000 | [diff] [blame] | 382 | SmallPtrSet<Instruction*, 4>& set = reverseDep[rem]; |
| 383 | for (SmallPtrSet<Instruction*, 4>::iterator I = set.begin(), E = set.end(); |
| 384 | I != E; ++I) { |
David Greene | df46419 | 2007-07-31 20:01:27 +0000 | [diff] [blame] | 385 | // Insert the new dependencies |
| 386 | // Mark it as unconfirmed as long as it is not the non-local flag |
Owen Anderson | dbbe816 | 2007-08-07 00:33:45 +0000 | [diff] [blame] | 387 | depGraphLocal[*I] = std::make_pair(newDep, !newDep); |
David Greene | df46419 | 2007-07-31 20:01:27 +0000 | [diff] [blame] | 388 | } |
Owen Anderson | dbbe816 | 2007-08-07 00:33:45 +0000 | [diff] [blame] | 389 | reverseDep.erase(rem); |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 390 | } |
| 391 | |
Owen Anderson | 1cb960a | 2007-07-12 00:06:21 +0000 | [diff] [blame] | 392 | getAnalysis<AliasAnalysis>().deleteValue(rem); |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 393 | } |