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 |
| 12 | // alias analysis information, and tries to provide a lazy, caching interface to |
| 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 | 0cd3203 | 2007-07-25 19:57:03 +0000 | [diff] [blame] | 29 | Instruction* MemoryDependenceAnalysis::NonLocal = (Instruction*)-2; |
| 30 | Instruction* MemoryDependenceAnalysis::None = (Instruction*)-3; |
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 | faac518 | 2007-07-16 21:52:50 +0000 | [diff] [blame] | 45 | Instruction* MemoryDependenceAnalysis::getCallSiteDependency(CallSite C, Instruction* start, |
| 46 | bool local) { |
Owen Anderson | 5f32320 | 2007-07-10 17:59:22 +0000 | [diff] [blame] | 47 | assert(local && "Non-local memory dependence analysis not yet implemented"); |
| 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 | |
| 54 | while (QI != blockBegin) { |
| 55 | --QI; |
| 56 | |
| 57 | // If this inst is a memory op, get the pointer it accessed |
| 58 | Value* pointer = 0; |
| 59 | uint64_t pointerSize = 0; |
| 60 | if (StoreInst* S = dyn_cast<StoreInst>(QI)) { |
| 61 | pointer = S->getPointerOperand(); |
| 62 | pointerSize = TD.getTypeSize(S->getOperand(0)->getType()); |
| 63 | } else if (LoadInst* L = dyn_cast<LoadInst>(QI)) { |
| 64 | pointer = L->getPointerOperand(); |
| 65 | pointerSize = TD.getTypeSize(L->getType()); |
| 66 | } else if (AllocationInst* AI = dyn_cast<AllocationInst>(QI)) { |
| 67 | pointer = AI; |
| 68 | if (ConstantInt* C = dyn_cast<ConstantInt>(AI->getArraySize())) |
Owen Anderson | 8e85048 | 2007-07-10 20:48:38 +0000 | [diff] [blame] | 69 | pointerSize = C->getZExtValue() * TD.getTypeSize(AI->getAllocatedType()); |
Owen Anderson | 5f32320 | 2007-07-10 17:59:22 +0000 | [diff] [blame] | 70 | else |
| 71 | pointerSize = ~0UL; |
Owen Anderson | 06b6e82 | 2007-07-10 18:43:15 +0000 | [diff] [blame] | 72 | } else if (VAArgInst* V = dyn_cast<VAArgInst>(QI)) { |
| 73 | pointer = V->getOperand(0); |
| 74 | pointerSize = TD.getTypeSize(V->getType()); |
Owen Anderson | 5f32320 | 2007-07-10 17:59:22 +0000 | [diff] [blame] | 75 | } else if (FreeInst* F = dyn_cast<FreeInst>(QI)) { |
| 76 | pointer = F->getPointerOperand(); |
| 77 | |
| 78 | // FreeInsts erase the entire structure |
| 79 | pointerSize = ~0UL; |
| 80 | } else if (CallSite::get(QI).getInstruction() != 0) { |
| 81 | if (AA.getModRefInfo(C, CallSite::get(QI)) != AliasAnalysis::NoModRef) { |
| 82 | depGraphLocal.insert(std::make_pair(C.getInstruction(), std::make_pair(QI, true))); |
| 83 | reverseDep.insert(std::make_pair(QI, C.getInstruction())); |
| 84 | return QI; |
| 85 | } else { |
| 86 | continue; |
| 87 | } |
Owen Anderson | 202da14 | 2007-07-10 20:39:07 +0000 | [diff] [blame] | 88 | } else |
| 89 | continue; |
Owen Anderson | 5f32320 | 2007-07-10 17:59:22 +0000 | [diff] [blame] | 90 | |
| 91 | if (AA.getModRefInfo(C, pointer, pointerSize) != AliasAnalysis::NoModRef) { |
| 92 | depGraphLocal.insert(std::make_pair(C.getInstruction(), std::make_pair(QI, true))); |
| 93 | reverseDep.insert(std::make_pair(QI, C.getInstruction())); |
| 94 | return QI; |
| 95 | } |
| 96 | } |
| 97 | |
| 98 | // No dependence found |
| 99 | depGraphLocal.insert(std::make_pair(C.getInstruction(), std::make_pair(NonLocal, true))); |
| 100 | reverseDep.insert(std::make_pair(NonLocal, C.getInstruction())); |
| 101 | return NonLocal; |
| 102 | } |
| 103 | |
Owen Anderson | 0cd3203 | 2007-07-25 19:57:03 +0000 | [diff] [blame] | 104 | bool MemoryDependenceAnalysis::nonLocalHelper(Instruction* query, |
| 105 | BasicBlock* block, |
Owen Anderson | 3dfcf33 | 2007-07-25 21:26:36 +0000 | [diff] [blame] | 106 | DenseMap<BasicBlock*, Value*>& resp, |
| 107 | SmallPtrSet<BasicBlock*, 4>& visited) { |
Owen Anderson | 0cd3203 | 2007-07-25 19:57:03 +0000 | [diff] [blame] | 108 | if (resp.count(block)) |
| 109 | return resp[block] != None; |
Owen Anderson | 4beedbd | 2007-07-24 21:52:37 +0000 | [diff] [blame] | 110 | |
Owen Anderson | 0cd3203 | 2007-07-25 19:57:03 +0000 | [diff] [blame] | 111 | Instruction* localDep = getDependency(query, 0, block); |
Owen Anderson | 4beedbd | 2007-07-24 21:52:37 +0000 | [diff] [blame] | 112 | if (localDep != NonLocal) { |
Owen Anderson | 0cd3203 | 2007-07-25 19:57:03 +0000 | [diff] [blame] | 113 | resp.insert(std::make_pair(block, localDep)); |
| 114 | return true; |
Owen Anderson | 4beedbd | 2007-07-24 21:52:37 +0000 | [diff] [blame] | 115 | } |
| 116 | |
Owen Anderson | 3dfcf33 | 2007-07-25 21:26:36 +0000 | [diff] [blame] | 117 | visited.insert(block); |
| 118 | |
Owen Anderson | 0cd3203 | 2007-07-25 19:57:03 +0000 | [diff] [blame] | 119 | bool inserted = false; |
Owen Anderson | a377a24 | 2007-07-26 18:57:04 +0000 | [diff] [blame] | 120 | bool predOnStack = false; |
Owen Anderson | 4beedbd | 2007-07-24 21:52:37 +0000 | [diff] [blame] | 121 | for (pred_iterator PI = pred_begin(block), PE = pred_end(block); |
Owen Anderson | 0cd3203 | 2007-07-25 19:57:03 +0000 | [diff] [blame] | 122 | PI != PE; ++PI) |
Owen Anderson | 3dfcf33 | 2007-07-25 21:26:36 +0000 | [diff] [blame] | 123 | if (!visited.count(*PI)) |
| 124 | inserted |= nonLocalHelper(query, *PI, resp, visited); |
Owen Anderson | a377a24 | 2007-07-26 18:57:04 +0000 | [diff] [blame] | 125 | else |
| 126 | predOnStack = true; |
| 127 | |
Owen Anderson | 3dfcf33 | 2007-07-25 21:26:36 +0000 | [diff] [blame] | 128 | visited.erase(block); |
Owen Anderson | a377a24 | 2007-07-26 18:57:04 +0000 | [diff] [blame] | 129 | |
| 130 | if (!inserted && !predOnStack) |
| 131 | resp.insert(std::make_pair(block, None)); |
Owen Anderson | 45c8388 | 2007-07-30 17:29:24 +0000 | [diff] [blame] | 132 | else if (inserted && predOnStack) |
| 133 | resp.insert(std::make_pair(block, NonLocal)); |
Owen Anderson | 4beedbd | 2007-07-24 21:52:37 +0000 | [diff] [blame] | 134 | |
Owen Anderson | 0cd3203 | 2007-07-25 19:57:03 +0000 | [diff] [blame] | 135 | return inserted; |
Owen Anderson | 4beedbd | 2007-07-24 21:52:37 +0000 | [diff] [blame] | 136 | } |
| 137 | |
Owen Anderson | 0cd3203 | 2007-07-25 19:57:03 +0000 | [diff] [blame] | 138 | bool MemoryDependenceAnalysis::getNonLocalDependency(Instruction* query, |
| 139 | DenseMap<BasicBlock*, Value*>& resp) { |
Owen Anderson | 4beedbd | 2007-07-24 21:52:37 +0000 | [diff] [blame] | 140 | Instruction* localDep = getDependency(query); |
| 141 | if (localDep != NonLocal) { |
Owen Anderson | 0cd3203 | 2007-07-25 19:57:03 +0000 | [diff] [blame] | 142 | resp.insert(std::make_pair(query->getParent(), localDep)); |
| 143 | return true; |
Owen Anderson | 4beedbd | 2007-07-24 21:52:37 +0000 | [diff] [blame] | 144 | } |
| 145 | |
Owen Anderson | 0cd3203 | 2007-07-25 19:57:03 +0000 | [diff] [blame] | 146 | bool inserted = false; |
Owen Anderson | 3dfcf33 | 2007-07-25 21:26:36 +0000 | [diff] [blame] | 147 | SmallPtrSet<BasicBlock*, 4> visited; |
| 148 | visited.insert(query->getParent()); |
Owen Anderson | 0cd3203 | 2007-07-25 19:57:03 +0000 | [diff] [blame] | 149 | |
Owen Anderson | 4beedbd | 2007-07-24 21:52:37 +0000 | [diff] [blame] | 150 | BasicBlock* parent = query->getParent(); |
| 151 | for (pred_iterator PI = pred_begin(parent), PE = pred_end(parent); |
| 152 | PI != PE; ++PI) { |
Owen Anderson | 3dfcf33 | 2007-07-25 21:26:36 +0000 | [diff] [blame] | 153 | if (!visited.count(*PI)) |
| 154 | inserted |= nonLocalHelper(query, *PI, resp, visited); |
Owen Anderson | 4beedbd | 2007-07-24 21:52:37 +0000 | [diff] [blame] | 155 | } |
| 156 | |
Owen Anderson | 0cd3203 | 2007-07-25 19:57:03 +0000 | [diff] [blame] | 157 | if (!inserted) |
| 158 | resp.insert(std::make_pair(query->getParent(), None)); |
Owen Anderson | 4beedbd | 2007-07-24 21:52:37 +0000 | [diff] [blame] | 159 | |
Owen Anderson | 0cd3203 | 2007-07-25 19:57:03 +0000 | [diff] [blame] | 160 | return inserted; |
Owen Anderson | 4beedbd | 2007-07-24 21:52:37 +0000 | [diff] [blame] | 161 | } |
| 162 | |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 163 | /// getDependency - Return the instruction on which a memory operation |
Owen Anderson | 6b278fc | 2007-07-10 17:08:11 +0000 | [diff] [blame] | 164 | /// depends. The local paramter indicates if the query should only |
| 165 | /// evaluate dependencies within the same basic block. |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 166 | Instruction* MemoryDependenceAnalysis::getDependency(Instruction* query, |
Owen Anderson | faac518 | 2007-07-16 21:52:50 +0000 | [diff] [blame] | 167 | Instruction* start, |
Owen Anderson | 4beedbd | 2007-07-24 21:52:37 +0000 | [diff] [blame] | 168 | BasicBlock* block) { |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 169 | // Start looking for dependencies with the queried inst |
| 170 | BasicBlock::iterator QI = query; |
| 171 | |
| 172 | // Check for a cached result |
| 173 | std::pair<Instruction*, bool> cachedResult = depGraphLocal[query]; |
| 174 | // If we have a _confirmed_ cached entry, return it |
| 175 | if (cachedResult.second) |
| 176 | return cachedResult.first; |
Owen Anderson | 0cd3203 | 2007-07-25 19:57:03 +0000 | [diff] [blame] | 177 | else if (cachedResult.first && cachedResult.first != NonLocal) |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 178 | // If we have an unconfirmed cached entry, we can start our search from there |
| 179 | QI = cachedResult.first; |
| 180 | |
Owen Anderson | faac518 | 2007-07-16 21:52:50 +0000 | [diff] [blame] | 181 | if (start) |
| 182 | QI = start; |
Owen Anderson | 0cd3203 | 2007-07-25 19:57:03 +0000 | [diff] [blame] | 183 | else if (!start && block) |
| 184 | QI = block->end(); |
Owen Anderson | faac518 | 2007-07-16 21:52:50 +0000 | [diff] [blame] | 185 | |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 186 | AliasAnalysis& AA = getAnalysis<AliasAnalysis>(); |
Owen Anderson | 6b278fc | 2007-07-10 17:08:11 +0000 | [diff] [blame] | 187 | TargetData& TD = getAnalysis<TargetData>(); |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 188 | |
| 189 | // Get the pointer value for which dependence will be determined |
| 190 | Value* dependee = 0; |
Owen Anderson | 6b278fc | 2007-07-10 17:08:11 +0000 | [diff] [blame] | 191 | uint64_t dependeeSize = 0; |
Owen Anderson | e314eb3 | 2007-07-10 18:11:42 +0000 | [diff] [blame] | 192 | bool queryIsVolatile = false; |
Owen Anderson | faac518 | 2007-07-16 21:52:50 +0000 | [diff] [blame] | 193 | if (StoreInst* S = dyn_cast<StoreInst>(query)) { |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 194 | dependee = S->getPointerOperand(); |
Owen Anderson | 7a616a1 | 2007-07-10 17:25:03 +0000 | [diff] [blame] | 195 | dependeeSize = TD.getTypeSize(S->getOperand(0)->getType()); |
Owen Anderson | e314eb3 | 2007-07-10 18:11:42 +0000 | [diff] [blame] | 196 | queryIsVolatile = S->isVolatile(); |
Owen Anderson | faac518 | 2007-07-16 21:52:50 +0000 | [diff] [blame] | 197 | } else if (LoadInst* L = dyn_cast<LoadInst>(query)) { |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 198 | dependee = L->getPointerOperand(); |
Owen Anderson | 7a616a1 | 2007-07-10 17:25:03 +0000 | [diff] [blame] | 199 | dependeeSize = TD.getTypeSize(L->getType()); |
Owen Anderson | e314eb3 | 2007-07-10 18:11:42 +0000 | [diff] [blame] | 200 | queryIsVolatile = L->isVolatile(); |
Owen Anderson | faac518 | 2007-07-16 21:52:50 +0000 | [diff] [blame] | 201 | } else if (VAArgInst* V = dyn_cast<VAArgInst>(query)) { |
Owen Anderson | 06b6e82 | 2007-07-10 18:43:15 +0000 | [diff] [blame] | 202 | dependee = V->getOperand(0); |
| 203 | dependeeSize = TD.getTypeSize(V->getType()); |
Owen Anderson | faac518 | 2007-07-16 21:52:50 +0000 | [diff] [blame] | 204 | } else if (FreeInst* F = dyn_cast<FreeInst>(query)) { |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 205 | dependee = F->getPointerOperand(); |
Owen Anderson | 6b278fc | 2007-07-10 17:08:11 +0000 | [diff] [blame] | 206 | |
| 207 | // FreeInsts erase the entire structure, not just a field |
| 208 | dependeeSize = ~0UL; |
Owen Anderson | faac518 | 2007-07-16 21:52:50 +0000 | [diff] [blame] | 209 | } else if (CallSite::get(query).getInstruction() != 0) |
| 210 | return getCallSiteDependency(CallSite::get(query), start); |
Owen Anderson | 5f32320 | 2007-07-10 17:59:22 +0000 | [diff] [blame] | 211 | else if (isa<AllocationInst>(query)) |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 212 | return None; |
Owen Anderson | 7a616a1 | 2007-07-10 17:25:03 +0000 | [diff] [blame] | 213 | else |
Owen Anderson | 6b278fc | 2007-07-10 17:08:11 +0000 | [diff] [blame] | 214 | return None; |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 215 | |
Owen Anderson | 4beedbd | 2007-07-24 21:52:37 +0000 | [diff] [blame] | 216 | BasicBlock::iterator blockBegin = block ? block->begin() |
| 217 | : query->getParent()->begin(); |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 218 | |
| 219 | while (QI != blockBegin) { |
Owen Anderson | 6b278fc | 2007-07-10 17:08:11 +0000 | [diff] [blame] | 220 | --QI; |
| 221 | |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 222 | // If this inst is a memory op, get the pointer it accessed |
| 223 | Value* pointer = 0; |
Owen Anderson | 6b278fc | 2007-07-10 17:08:11 +0000 | [diff] [blame] | 224 | uint64_t pointerSize = 0; |
| 225 | if (StoreInst* S = dyn_cast<StoreInst>(QI)) { |
Owen Anderson | e314eb3 | 2007-07-10 18:11:42 +0000 | [diff] [blame] | 226 | // All volatile loads/stores depend on each other |
| 227 | if (queryIsVolatile && S->isVolatile()) { |
Owen Anderson | 0cd3203 | 2007-07-25 19:57:03 +0000 | [diff] [blame] | 228 | if (!start || block) { |
Owen Anderson | faac518 | 2007-07-16 21:52:50 +0000 | [diff] [blame] | 229 | depGraphLocal.insert(std::make_pair(query, std::make_pair(S, true))); |
| 230 | reverseDep.insert(std::make_pair(S, query)); |
| 231 | } |
| 232 | |
Owen Anderson | e314eb3 | 2007-07-10 18:11:42 +0000 | [diff] [blame] | 233 | return S; |
| 234 | } |
| 235 | |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 236 | pointer = S->getPointerOperand(); |
Owen Anderson | 7a616a1 | 2007-07-10 17:25:03 +0000 | [diff] [blame] | 237 | pointerSize = TD.getTypeSize(S->getOperand(0)->getType()); |
Owen Anderson | 6b278fc | 2007-07-10 17:08:11 +0000 | [diff] [blame] | 238 | } else if (LoadInst* L = dyn_cast<LoadInst>(QI)) { |
Owen Anderson | e314eb3 | 2007-07-10 18:11:42 +0000 | [diff] [blame] | 239 | // All volatile loads/stores depend on each other |
| 240 | if (queryIsVolatile && L->isVolatile()) { |
Owen Anderson | 0cd3203 | 2007-07-25 19:57:03 +0000 | [diff] [blame] | 241 | if (!start || block) { |
Owen Anderson | faac518 | 2007-07-16 21:52:50 +0000 | [diff] [blame] | 242 | depGraphLocal.insert(std::make_pair(query, std::make_pair(L, true))); |
| 243 | reverseDep.insert(std::make_pair(L, query)); |
| 244 | } |
| 245 | |
Owen Anderson | e314eb3 | 2007-07-10 18:11:42 +0000 | [diff] [blame] | 246 | return L; |
| 247 | } |
| 248 | |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 249 | pointer = L->getPointerOperand(); |
Owen Anderson | 7a616a1 | 2007-07-10 17:25:03 +0000 | [diff] [blame] | 250 | pointerSize = TD.getTypeSize(L->getType()); |
Owen Anderson | 6b278fc | 2007-07-10 17:08:11 +0000 | [diff] [blame] | 251 | } else if (AllocationInst* AI = dyn_cast<AllocationInst>(QI)) { |
| 252 | pointer = AI; |
Owen Anderson | 7a616a1 | 2007-07-10 17:25:03 +0000 | [diff] [blame] | 253 | if (ConstantInt* C = dyn_cast<ConstantInt>(AI->getArraySize())) |
Owen Anderson | 8e85048 | 2007-07-10 20:48:38 +0000 | [diff] [blame] | 254 | pointerSize = C->getZExtValue() * TD.getTypeSize(AI->getAllocatedType()); |
Owen Anderson | 6b278fc | 2007-07-10 17:08:11 +0000 | [diff] [blame] | 255 | else |
| 256 | pointerSize = ~0UL; |
Owen Anderson | 06b6e82 | 2007-07-10 18:43:15 +0000 | [diff] [blame] | 257 | } else if (VAArgInst* V = dyn_cast<VAArgInst>(QI)) { |
| 258 | pointer = V->getOperand(0); |
| 259 | pointerSize = TD.getTypeSize(V->getType()); |
Owen Anderson | 6b278fc | 2007-07-10 17:08:11 +0000 | [diff] [blame] | 260 | } else if (FreeInst* F = dyn_cast<FreeInst>(QI)) { |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 261 | pointer = F->getPointerOperand(); |
Owen Anderson | 6b278fc | 2007-07-10 17:08:11 +0000 | [diff] [blame] | 262 | |
| 263 | // FreeInsts erase the entire structure |
| 264 | pointerSize = ~0UL; |
Owen Anderson | 5f32320 | 2007-07-10 17:59:22 +0000 | [diff] [blame] | 265 | } else if (CallSite::get(QI).getInstruction() != 0) { |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 266 | // Call insts need special handling. Check is they can modify our pointer |
Owen Anderson | 5f32320 | 2007-07-10 17:59:22 +0000 | [diff] [blame] | 267 | if (AA.getModRefInfo(CallSite::get(QI), dependee, dependeeSize) != |
| 268 | AliasAnalysis::NoModRef) { |
Owen Anderson | 0cd3203 | 2007-07-25 19:57:03 +0000 | [diff] [blame] | 269 | if (!start || block) { |
Owen Anderson | faac518 | 2007-07-16 21:52:50 +0000 | [diff] [blame] | 270 | depGraphLocal.insert(std::make_pair(query, std::make_pair(QI, true))); |
| 271 | reverseDep.insert(std::make_pair(QI, query)); |
| 272 | } |
| 273 | |
Owen Anderson | 5f32320 | 2007-07-10 17:59:22 +0000 | [diff] [blame] | 274 | return QI; |
Owen Anderson | 7a616a1 | 2007-07-10 17:25:03 +0000 | [diff] [blame] | 275 | } else { |
| 276 | continue; |
| 277 | } |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 278 | } |
| 279 | |
| 280 | // If we found a pointer, check if it could be the same as our pointer |
| 281 | if (pointer) { |
Owen Anderson | 6b278fc | 2007-07-10 17:08:11 +0000 | [diff] [blame] | 282 | AliasAnalysis::AliasResult R = AA.alias(pointer, pointerSize, |
| 283 | dependee, dependeeSize); |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 284 | |
| 285 | if (R != AliasAnalysis::NoAlias) { |
Owen Anderson | 0cd3203 | 2007-07-25 19:57:03 +0000 | [diff] [blame] | 286 | if (!start || block) { |
Owen Anderson | faac518 | 2007-07-16 21:52:50 +0000 | [diff] [blame] | 287 | depGraphLocal.insert(std::make_pair(query, std::make_pair(QI, true))); |
| 288 | reverseDep.insert(std::make_pair(QI, query)); |
| 289 | } |
| 290 | |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 291 | return QI; |
| 292 | } |
| 293 | } |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 294 | } |
| 295 | |
| 296 | // If we found nothing, return the non-local flag |
Owen Anderson | 0cd3203 | 2007-07-25 19:57:03 +0000 | [diff] [blame] | 297 | if (!start || block) { |
Owen Anderson | faac518 | 2007-07-16 21:52:50 +0000 | [diff] [blame] | 298 | depGraphLocal.insert(std::make_pair(query, |
| 299 | std::make_pair(NonLocal, true))); |
| 300 | reverseDep.insert(std::make_pair(NonLocal, query)); |
| 301 | } |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 302 | |
| 303 | return NonLocal; |
| 304 | } |
| 305 | |
| 306 | /// removeInstruction - Remove an instruction from the dependence analysis, |
| 307 | /// updating the dependence of instructions that previously depended on it. |
| 308 | void MemoryDependenceAnalysis::removeInstruction(Instruction* rem) { |
| 309 | // Figure out the new dep for things that currently depend on rem |
| 310 | Instruction* newDep = NonLocal; |
David Greene | df46419 | 2007-07-31 20:01:27 +0000 | [diff] [blame] | 311 | |
| 312 | depMapType::iterator depGraphEntry = depGraphLocal.find(rem); |
| 313 | // We assume here that it's not in the reverse map if it's not in |
| 314 | // the dep map. Checking it could be expensive, so don't do it. |
| 315 | |
| 316 | if (depGraphEntry != depGraphLocal.end()) { |
| 317 | if (depGraphEntry->second.first != NonLocal && |
| 318 | depGraphEntry->second.second) { |
| 319 | // If we have dep info for rem, set them to it |
| 320 | BasicBlock::iterator RI = depGraphEntry->second.first; |
| 321 | RI++; |
| 322 | newDep = RI; |
| 323 | } else if (depGraphEntry->second.first == NonLocal && |
| 324 | depGraphEntry->second.second ) { |
| 325 | // If we have a confirmed non-local flag, use it |
| 326 | newDep = NonLocal; |
| 327 | } else { |
| 328 | // Otherwise, use the immediate successor of rem |
| 329 | // NOTE: This is because, when getDependence is called, it will first check |
| 330 | // the immediate predecessor of what is in the cache. |
| 331 | BasicBlock::iterator RI = rem; |
| 332 | RI++; |
| 333 | newDep = RI; |
| 334 | } |
| 335 | |
| 336 | std::multimap<Instruction*, Instruction*>::iterator I = reverseDep.find(rem); |
| 337 | while (I != reverseDep.end() && I->first == rem) { |
| 338 | // Insert the new dependencies |
| 339 | // Mark it as unconfirmed as long as it is not the non-local flag |
| 340 | depGraphLocal[I->second] = std::make_pair(newDep, !newDep); |
| 341 | reverseDep.erase(I); |
| 342 | I = reverseDep.find(rem); |
| 343 | } |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 344 | } |
| 345 | |
Owen Anderson | 1cb960a | 2007-07-12 00:06:21 +0000 | [diff] [blame] | 346 | getAnalysis<AliasAnalysis>().deleteValue(rem); |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 347 | } |