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 | // |
Chris Lattner | 4ee451d | 2007-12-29 20:36:04 +0000 | [diff] [blame] | 5 | // This file is distributed under the University of Illinois Open Source |
| 6 | // License. See LICENSE.TXT for details. |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 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 | |
Chris Lattner | 0e575f4 | 2008-11-28 21:45:17 +0000 | [diff] [blame] | 17 | #define DEBUG_TYPE "memdep" |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 18 | #include "llvm/Analysis/MemoryDependenceAnalysis.h" |
Owen Anderson | 7a616a1 | 2007-07-10 17:25:03 +0000 | [diff] [blame] | 19 | #include "llvm/Constants.h" |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 20 | #include "llvm/Instructions.h" |
| 21 | #include "llvm/Function.h" |
| 22 | #include "llvm/Analysis/AliasAnalysis.h" |
Chris Lattner | baad888 | 2008-11-28 22:28:27 +0000 | [diff] [blame^] | 23 | #include "llvm/ADT/Statistic.h" |
| 24 | #include "llvm/ADT/STLExtras.h" |
Owen Anderson | 4beedbd | 2007-07-24 21:52:37 +0000 | [diff] [blame] | 25 | #include "llvm/Support/CFG.h" |
Tanya Lattner | 63aa160 | 2008-02-06 00:54:55 +0000 | [diff] [blame] | 26 | #include "llvm/Support/CommandLine.h" |
Chris Lattner | 0e575f4 | 2008-11-28 21:45:17 +0000 | [diff] [blame] | 27 | #include "llvm/Support/Debug.h" |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 28 | #include "llvm/Target/TargetData.h" |
Owen Anderson | 7fad7e3 | 2007-09-09 21:43:49 +0000 | [diff] [blame] | 29 | |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 30 | using namespace llvm; |
| 31 | |
Dan Gohman | 844731a | 2008-05-13 00:00:25 +0000 | [diff] [blame] | 32 | // Control the calculation of non-local dependencies by only examining the |
| 33 | // predecessors if the basic block has less than X amount (50 by default). |
| 34 | static cl::opt<int> |
| 35 | PredLimit("nonlocaldep-threshold", cl::Hidden, cl::init(50), |
| 36 | cl::desc("Control the calculation of non-local" |
| 37 | "dependencies (default = 50)")); |
Tanya Lattner | 63aa160 | 2008-02-06 00:54:55 +0000 | [diff] [blame] | 38 | |
Owen Anderson | 7fad7e3 | 2007-09-09 21:43:49 +0000 | [diff] [blame] | 39 | STATISTIC(NumCacheNonlocal, "Number of cached non-local responses"); |
| 40 | STATISTIC(NumUncacheNonlocal, "Number of uncached non-local responses"); |
| 41 | |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 42 | char MemoryDependenceAnalysis::ID = 0; |
| 43 | |
Owen Anderson | 9528f11 | 2007-08-09 04:42:44 +0000 | [diff] [blame] | 44 | Instruction* const MemoryDependenceAnalysis::NonLocal = (Instruction*)-3; |
| 45 | Instruction* const MemoryDependenceAnalysis::None = (Instruction*)-4; |
Owen Anderson | 742f9b6 | 2007-09-19 16:13:57 +0000 | [diff] [blame] | 46 | Instruction* const MemoryDependenceAnalysis::Dirty = (Instruction*)-5; |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 47 | |
| 48 | // Register this pass... |
Owen Anderson | 776ee1f | 2007-07-10 20:21:08 +0000 | [diff] [blame] | 49 | static RegisterPass<MemoryDependenceAnalysis> X("memdep", |
Chris Lattner | 0e575f4 | 2008-11-28 21:45:17 +0000 | [diff] [blame] | 50 | "Memory Dependence Analysis", false, true); |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 51 | |
Chris Lattner | 0e575f4 | 2008-11-28 21:45:17 +0000 | [diff] [blame] | 52 | /// verifyRemoved - Verify that the specified instruction does not occur |
| 53 | /// in our internal data structures. |
Chris Lattner | 8b589fa | 2008-11-28 21:42:09 +0000 | [diff] [blame] | 54 | void MemoryDependenceAnalysis::verifyRemoved(Instruction *D) const { |
| 55 | for (depMapType::const_iterator I = depGraphLocal.begin(), |
| 56 | E = depGraphLocal.end(); I != E; ++I) { |
Chris Lattner | 0e575f4 | 2008-11-28 21:45:17 +0000 | [diff] [blame] | 57 | assert(I->first != D && "Inst occurs in data structures"); |
| 58 | assert(I->second.first != D && "Inst occurs in data structures"); |
Owen Anderson | 5fc4aba | 2007-12-08 01:37:09 +0000 | [diff] [blame] | 59 | } |
| 60 | |
Chris Lattner | 8b589fa | 2008-11-28 21:42:09 +0000 | [diff] [blame] | 61 | for (nonLocalDepMapType::const_iterator I = depGraphNonLocal.begin(), |
| 62 | E = depGraphNonLocal.end(); I != E; ++I) { |
Chris Lattner | 0e575f4 | 2008-11-28 21:45:17 +0000 | [diff] [blame] | 63 | assert(I->first != D && "Inst occurs in data structures"); |
Owen Anderson | d8f34fa | 2008-06-01 20:51:41 +0000 | [diff] [blame] | 64 | for (DenseMap<BasicBlock*, Value*>::iterator II = I->second.begin(), |
| 65 | EE = I->second.end(); II != EE; ++II) |
Chris Lattner | 0e575f4 | 2008-11-28 21:45:17 +0000 | [diff] [blame] | 66 | assert(II->second != D && "Inst occurs in data structures"); |
Owen Anderson | 5fc4aba | 2007-12-08 01:37:09 +0000 | [diff] [blame] | 67 | } |
| 68 | |
Chris Lattner | 8b589fa | 2008-11-28 21:42:09 +0000 | [diff] [blame] | 69 | for (reverseDepMapType::const_iterator I = reverseDep.begin(), |
| 70 | E = reverseDep.end(); I != E; ++I) |
| 71 | for (SmallPtrSet<Instruction*, 4>::const_iterator II = I->second.begin(), |
| 72 | EE = I->second.end(); II != EE; ++II) |
Chris Lattner | 0e575f4 | 2008-11-28 21:45:17 +0000 | [diff] [blame] | 73 | assert(*II != D && "Inst occurs in data structures"); |
Owen Anderson | 5fc4aba | 2007-12-08 01:37:09 +0000 | [diff] [blame] | 74 | |
Chris Lattner | 8b589fa | 2008-11-28 21:42:09 +0000 | [diff] [blame] | 75 | for (reverseDepMapType::const_iterator I = reverseDepNonLocal.begin(), |
| 76 | E = reverseDepNonLocal.end(); |
Owen Anderson | 5fc4aba | 2007-12-08 01:37:09 +0000 | [diff] [blame] | 77 | I != E; ++I) |
Chris Lattner | 8b589fa | 2008-11-28 21:42:09 +0000 | [diff] [blame] | 78 | for (SmallPtrSet<Instruction*, 4>::const_iterator II = I->second.begin(), |
| 79 | EE = I->second.end(); II != EE; ++II) |
Chris Lattner | 0e575f4 | 2008-11-28 21:45:17 +0000 | [diff] [blame] | 80 | assert(*II != D && "Inst occurs in data structures"); |
Owen Anderson | 5fc4aba | 2007-12-08 01:37:09 +0000 | [diff] [blame] | 81 | } |
| 82 | |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 83 | /// getAnalysisUsage - Does not modify anything. It uses Alias Analysis. |
| 84 | /// |
| 85 | void MemoryDependenceAnalysis::getAnalysisUsage(AnalysisUsage &AU) const { |
| 86 | AU.setPreservesAll(); |
| 87 | AU.addRequiredTransitive<AliasAnalysis>(); |
| 88 | AU.addRequiredTransitive<TargetData>(); |
| 89 | } |
| 90 | |
Owen Anderson | 642a9e3 | 2007-08-08 22:26:03 +0000 | [diff] [blame] | 91 | /// getCallSiteDependency - Private helper for finding the local dependencies |
| 92 | /// of a call site. |
Owen Anderson | 9528f11 | 2007-08-09 04:42:44 +0000 | [diff] [blame] | 93 | Instruction* MemoryDependenceAnalysis::getCallSiteDependency(CallSite C, |
Chris Lattner | 0e575f4 | 2008-11-28 21:45:17 +0000 | [diff] [blame] | 94 | Instruction* start, |
Owen Anderson | 80b1f09 | 2007-08-08 22:01:54 +0000 | [diff] [blame] | 95 | BasicBlock* block) { |
Owen Anderson | 5f32320 | 2007-07-10 17:59:22 +0000 | [diff] [blame] | 96 | |
Owen Anderson | 5fc4aba | 2007-12-08 01:37:09 +0000 | [diff] [blame] | 97 | std::pair<Instruction*, bool>& cachedResult = |
| 98 | depGraphLocal[C.getInstruction()]; |
Owen Anderson | 5f32320 | 2007-07-10 17:59:22 +0000 | [diff] [blame] | 99 | AliasAnalysis& AA = getAnalysis<AliasAnalysis>(); |
| 100 | TargetData& TD = getAnalysis<TargetData>(); |
| 101 | BasicBlock::iterator blockBegin = C.getInstruction()->getParent()->begin(); |
| 102 | BasicBlock::iterator QI = C.getInstruction(); |
| 103 | |
Duncan Sands | af8bc26 | 2008-09-11 19:41:10 +0000 | [diff] [blame] | 104 | // If the starting point was specified, use it |
Owen Anderson | dbbe816 | 2007-08-07 00:33:45 +0000 | [diff] [blame] | 105 | if (start) { |
| 106 | QI = start; |
Dan Gohman | 6faaef5 | 2008-03-31 22:08:00 +0000 | [diff] [blame] | 107 | blockBegin = start->getParent()->begin(); |
Owen Anderson | 642a9e3 | 2007-08-08 22:26:03 +0000 | [diff] [blame] | 108 | // If the starting point wasn't specified, but the block was, use it |
Owen Anderson | dbbe816 | 2007-08-07 00:33:45 +0000 | [diff] [blame] | 109 | } else if (!start && block) { |
| 110 | QI = block->end(); |
Dan Gohman | 6faaef5 | 2008-03-31 22:08:00 +0000 | [diff] [blame] | 111 | blockBegin = block->begin(); |
Owen Anderson | dbbe816 | 2007-08-07 00:33:45 +0000 | [diff] [blame] | 112 | } |
| 113 | |
Owen Anderson | 642a9e3 | 2007-08-08 22:26:03 +0000 | [diff] [blame] | 114 | // Walk backwards through the block, looking for dependencies |
Owen Anderson | 5f32320 | 2007-07-10 17:59:22 +0000 | [diff] [blame] | 115 | while (QI != blockBegin) { |
| 116 | --QI; |
| 117 | |
| 118 | // If this inst is a memory op, get the pointer it accessed |
| 119 | Value* pointer = 0; |
| 120 | uint64_t pointerSize = 0; |
| 121 | if (StoreInst* S = dyn_cast<StoreInst>(QI)) { |
| 122 | pointer = S->getPointerOperand(); |
Duncan Sands | 514ab34 | 2007-11-01 20:53:16 +0000 | [diff] [blame] | 123 | pointerSize = TD.getTypeStoreSize(S->getOperand(0)->getType()); |
Owen Anderson | 5f32320 | 2007-07-10 17:59:22 +0000 | [diff] [blame] | 124 | } else if (AllocationInst* AI = dyn_cast<AllocationInst>(QI)) { |
| 125 | pointer = AI; |
| 126 | if (ConstantInt* C = dyn_cast<ConstantInt>(AI->getArraySize())) |
Chris Lattner | 57d4012 | 2008-11-28 21:16:44 +0000 | [diff] [blame] | 127 | pointerSize = C->getZExtValue() * |
Duncan Sands | 514ab34 | 2007-11-01 20:53:16 +0000 | [diff] [blame] | 128 | TD.getABITypeSize(AI->getAllocatedType()); |
Owen Anderson | 5f32320 | 2007-07-10 17:59:22 +0000 | [diff] [blame] | 129 | else |
| 130 | pointerSize = ~0UL; |
Owen Anderson | 06b6e82 | 2007-07-10 18:43:15 +0000 | [diff] [blame] | 131 | } else if (VAArgInst* V = dyn_cast<VAArgInst>(QI)) { |
| 132 | pointer = V->getOperand(0); |
Duncan Sands | 514ab34 | 2007-11-01 20:53:16 +0000 | [diff] [blame] | 133 | pointerSize = TD.getTypeStoreSize(V->getType()); |
Owen Anderson | 5f32320 | 2007-07-10 17:59:22 +0000 | [diff] [blame] | 134 | } else if (FreeInst* F = dyn_cast<FreeInst>(QI)) { |
| 135 | pointer = F->getPointerOperand(); |
| 136 | |
| 137 | // FreeInsts erase the entire structure |
| 138 | pointerSize = ~0UL; |
Owen Anderson | ff5a535 | 2008-05-13 21:25:37 +0000 | [diff] [blame] | 139 | } else if (CallSite::get(QI).getInstruction() != 0) { |
Owen Anderson | 00a6d14 | 2007-11-26 02:26:36 +0000 | [diff] [blame] | 140 | AliasAnalysis::ModRefBehavior result = |
Duncan Sands | dff6710 | 2007-12-01 07:51:45 +0000 | [diff] [blame] | 141 | AA.getModRefBehavior(CallSite::get(QI)); |
Owen Anderson | 241f653 | 2008-04-17 05:36:50 +0000 | [diff] [blame] | 142 | if (result != AliasAnalysis::DoesNotAccessMemory) { |
Owen Anderson | dbbe816 | 2007-08-07 00:33:45 +0000 | [diff] [blame] | 143 | if (!start && !block) { |
Owen Anderson | 5fc4aba | 2007-12-08 01:37:09 +0000 | [diff] [blame] | 144 | cachedResult.first = QI; |
| 145 | cachedResult.second = true; |
Owen Anderson | dbbe816 | 2007-08-07 00:33:45 +0000 | [diff] [blame] | 146 | reverseDep[QI].insert(C.getInstruction()); |
| 147 | } |
Owen Anderson | 5f32320 | 2007-07-10 17:59:22 +0000 | [diff] [blame] | 148 | return QI; |
| 149 | } else { |
| 150 | continue; |
| 151 | } |
Owen Anderson | 202da14 | 2007-07-10 20:39:07 +0000 | [diff] [blame] | 152 | } else |
| 153 | continue; |
Owen Anderson | 5f32320 | 2007-07-10 17:59:22 +0000 | [diff] [blame] | 154 | |
| 155 | if (AA.getModRefInfo(C, pointer, pointerSize) != AliasAnalysis::NoModRef) { |
Owen Anderson | dbbe816 | 2007-08-07 00:33:45 +0000 | [diff] [blame] | 156 | if (!start && !block) { |
Owen Anderson | 5fc4aba | 2007-12-08 01:37:09 +0000 | [diff] [blame] | 157 | cachedResult.first = QI; |
| 158 | cachedResult.second = true; |
Owen Anderson | dbbe816 | 2007-08-07 00:33:45 +0000 | [diff] [blame] | 159 | reverseDep[QI].insert(C.getInstruction()); |
| 160 | } |
Owen Anderson | 5f32320 | 2007-07-10 17:59:22 +0000 | [diff] [blame] | 161 | return QI; |
| 162 | } |
| 163 | } |
| 164 | |
| 165 | // No dependence found |
Owen Anderson | 5fc4aba | 2007-12-08 01:37:09 +0000 | [diff] [blame] | 166 | cachedResult.first = NonLocal; |
| 167 | cachedResult.second = true; |
Owen Anderson | dbbe816 | 2007-08-07 00:33:45 +0000 | [diff] [blame] | 168 | reverseDep[NonLocal].insert(C.getInstruction()); |
Owen Anderson | 5f32320 | 2007-07-10 17:59:22 +0000 | [diff] [blame] | 169 | return NonLocal; |
| 170 | } |
| 171 | |
Owen Anderson | 642a9e3 | 2007-08-08 22:26:03 +0000 | [diff] [blame] | 172 | /// nonLocalHelper - Private helper used to calculate non-local dependencies |
| 173 | /// by doing DFS on the predecessors of a block to find its dependencies |
Owen Anderson | 9066020 | 2007-08-01 22:01:54 +0000 | [diff] [blame] | 174 | void MemoryDependenceAnalysis::nonLocalHelper(Instruction* query, |
Owen Anderson | 0cd3203 | 2007-07-25 19:57:03 +0000 | [diff] [blame] | 175 | BasicBlock* block, |
Owen Anderson | 80b1f09 | 2007-08-08 22:01:54 +0000 | [diff] [blame] | 176 | DenseMap<BasicBlock*, Value*>& resp) { |
Owen Anderson | 642a9e3 | 2007-08-08 22:26:03 +0000 | [diff] [blame] | 177 | // Set of blocks that we've already visited in our DFS |
Owen Anderson | 9066020 | 2007-08-01 22:01:54 +0000 | [diff] [blame] | 178 | SmallPtrSet<BasicBlock*, 4> visited; |
Owen Anderson | ce4d88a | 2007-09-21 03:53:52 +0000 | [diff] [blame] | 179 | // If we're updating a dirtied cache entry, we don't need to reprocess |
| 180 | // already computed entries. |
| 181 | for (DenseMap<BasicBlock*, Value*>::iterator I = resp.begin(), |
| 182 | E = resp.end(); I != E; ++I) |
| 183 | if (I->second != Dirty) |
| 184 | visited.insert(I->first); |
| 185 | |
Owen Anderson | 642a9e3 | 2007-08-08 22:26:03 +0000 | [diff] [blame] | 186 | // Current stack of the DFS |
Owen Anderson | 9066020 | 2007-08-01 22:01:54 +0000 | [diff] [blame] | 187 | SmallVector<BasicBlock*, 4> stack; |
Owen Anderson | f062f10 | 2008-04-10 22:13:32 +0000 | [diff] [blame] | 188 | for (pred_iterator PI = pred_begin(block), PE = pred_end(block); |
| 189 | PI != PE; ++PI) |
| 190 | stack.push_back(*PI); |
Owen Anderson | 4beedbd | 2007-07-24 21:52:37 +0000 | [diff] [blame] | 191 | |
Owen Anderson | 642a9e3 | 2007-08-08 22:26:03 +0000 | [diff] [blame] | 192 | // Do a basic DFS |
Owen Anderson | 9066020 | 2007-08-01 22:01:54 +0000 | [diff] [blame] | 193 | while (!stack.empty()) { |
| 194 | BasicBlock* BB = stack.back(); |
| 195 | |
Owen Anderson | 642a9e3 | 2007-08-08 22:26:03 +0000 | [diff] [blame] | 196 | // If we've already visited this block, no need to revist |
Owen Anderson | 1c2763d | 2007-08-02 17:56:05 +0000 | [diff] [blame] | 197 | if (visited.count(BB)) { |
Owen Anderson | 9066020 | 2007-08-01 22:01:54 +0000 | [diff] [blame] | 198 | stack.pop_back(); |
| 199 | continue; |
| 200 | } |
| 201 | |
Owen Anderson | 642a9e3 | 2007-08-08 22:26:03 +0000 | [diff] [blame] | 202 | // If we find a new block with a local dependency for query, |
| 203 | // then we insert the new dependency and backtrack. |
Owen Anderson | 9066020 | 2007-08-01 22:01:54 +0000 | [diff] [blame] | 204 | if (BB != block) { |
Owen Anderson | 1c2763d | 2007-08-02 17:56:05 +0000 | [diff] [blame] | 205 | visited.insert(BB); |
| 206 | |
Owen Anderson | 9528f11 | 2007-08-09 04:42:44 +0000 | [diff] [blame] | 207 | Instruction* localDep = getDependency(query, 0, BB); |
Owen Anderson | 9066020 | 2007-08-01 22:01:54 +0000 | [diff] [blame] | 208 | if (localDep != NonLocal) { |
Owen Anderson | 9528f11 | 2007-08-09 04:42:44 +0000 | [diff] [blame] | 209 | resp.insert(std::make_pair(BB, localDep)); |
Owen Anderson | 1c2763d | 2007-08-02 17:56:05 +0000 | [diff] [blame] | 210 | stack.pop_back(); |
| 211 | |
Owen Anderson | 9066020 | 2007-08-01 22:01:54 +0000 | [diff] [blame] | 212 | continue; |
| 213 | } |
Owen Anderson | 642a9e3 | 2007-08-08 22:26:03 +0000 | [diff] [blame] | 214 | // If we re-encounter the starting block, we still need to search it |
| 215 | // because there might be a dependency in the starting block AFTER |
| 216 | // the position of the query. This is necessary to get loops right. |
Owen Anderson | f062f10 | 2008-04-10 22:13:32 +0000 | [diff] [blame] | 217 | } else if (BB == block) { |
Owen Anderson | 1c2763d | 2007-08-02 17:56:05 +0000 | [diff] [blame] | 218 | visited.insert(BB); |
| 219 | |
Owen Anderson | 9528f11 | 2007-08-09 04:42:44 +0000 | [diff] [blame] | 220 | Instruction* localDep = getDependency(query, 0, BB); |
Owen Anderson | 1c2763d | 2007-08-02 17:56:05 +0000 | [diff] [blame] | 221 | if (localDep != query) |
Owen Anderson | 9528f11 | 2007-08-09 04:42:44 +0000 | [diff] [blame] | 222 | resp.insert(std::make_pair(BB, localDep)); |
Owen Anderson | 1c2763d | 2007-08-02 17:56:05 +0000 | [diff] [blame] | 223 | |
| 224 | stack.pop_back(); |
| 225 | |
| 226 | continue; |
Owen Anderson | 9066020 | 2007-08-01 22:01:54 +0000 | [diff] [blame] | 227 | } |
| 228 | |
Owen Anderson | 642a9e3 | 2007-08-08 22:26:03 +0000 | [diff] [blame] | 229 | // If we didn't find anything, recurse on the precessors of this block |
Tanya Lattner | 63aa160 | 2008-02-06 00:54:55 +0000 | [diff] [blame] | 230 | // Only do this for blocks with a small number of predecessors. |
Owen Anderson | 9066020 | 2007-08-01 22:01:54 +0000 | [diff] [blame] | 231 | bool predOnStack = false; |
| 232 | bool inserted = false; |
Tanya Lattner | 63aa160 | 2008-02-06 00:54:55 +0000 | [diff] [blame] | 233 | if (std::distance(pred_begin(BB), pred_end(BB)) <= PredLimit) { |
| 234 | for (pred_iterator PI = pred_begin(BB), PE = pred_end(BB); |
| 235 | PI != PE; ++PI) |
| 236 | if (!visited.count(*PI)) { |
| 237 | stack.push_back(*PI); |
| 238 | inserted = true; |
| 239 | } else |
| 240 | predOnStack = true; |
| 241 | } |
Owen Anderson | 9066020 | 2007-08-01 22:01:54 +0000 | [diff] [blame] | 242 | |
Owen Anderson | 642a9e3 | 2007-08-08 22:26:03 +0000 | [diff] [blame] | 243 | // If we inserted a new predecessor, then we'll come back to this block |
Owen Anderson | 9066020 | 2007-08-01 22:01:54 +0000 | [diff] [blame] | 244 | if (inserted) |
| 245 | continue; |
Owen Anderson | 642a9e3 | 2007-08-08 22:26:03 +0000 | [diff] [blame] | 246 | // If we didn't insert because we have no predecessors, then this |
| 247 | // query has no dependency at all. |
Owen Anderson | 9066020 | 2007-08-01 22:01:54 +0000 | [diff] [blame] | 248 | else if (!inserted && !predOnStack) { |
Owen Anderson | 9528f11 | 2007-08-09 04:42:44 +0000 | [diff] [blame] | 249 | resp.insert(std::make_pair(BB, None)); |
Owen Anderson | 642a9e3 | 2007-08-08 22:26:03 +0000 | [diff] [blame] | 250 | // If we didn't insert because our predecessors are already on the stack, |
| 251 | // then we might still have a dependency, but it will be discovered during |
| 252 | // backtracking. |
Owen Anderson | 9066020 | 2007-08-01 22:01:54 +0000 | [diff] [blame] | 253 | } else if (!inserted && predOnStack){ |
Owen Anderson | 9528f11 | 2007-08-09 04:42:44 +0000 | [diff] [blame] | 254 | resp.insert(std::make_pair(BB, NonLocal)); |
Owen Anderson | 9066020 | 2007-08-01 22:01:54 +0000 | [diff] [blame] | 255 | } |
| 256 | |
| 257 | stack.pop_back(); |
Owen Anderson | 4beedbd | 2007-07-24 21:52:37 +0000 | [diff] [blame] | 258 | } |
Owen Anderson | 4beedbd | 2007-07-24 21:52:37 +0000 | [diff] [blame] | 259 | } |
| 260 | |
Owen Anderson | 80b1f09 | 2007-08-08 22:01:54 +0000 | [diff] [blame] | 261 | /// getNonLocalDependency - Fills the passed-in map with the non-local |
| 262 | /// dependencies of the queries. The map will contain NonLocal for |
| 263 | /// blocks between the query and its dependencies. |
Owen Anderson | 9066020 | 2007-08-01 22:01:54 +0000 | [diff] [blame] | 264 | void MemoryDependenceAnalysis::getNonLocalDependency(Instruction* query, |
Owen Anderson | 80b1f09 | 2007-08-08 22:01:54 +0000 | [diff] [blame] | 265 | DenseMap<BasicBlock*, Value*>& resp) { |
Owen Anderson | 4d13de4 | 2007-08-16 21:27:05 +0000 | [diff] [blame] | 266 | if (depGraphNonLocal.count(query)) { |
Owen Anderson | ce4d88a | 2007-09-21 03:53:52 +0000 | [diff] [blame] | 267 | DenseMap<BasicBlock*, Value*>& cached = depGraphNonLocal[query]; |
Owen Anderson | 7fad7e3 | 2007-09-09 21:43:49 +0000 | [diff] [blame] | 268 | NumCacheNonlocal++; |
Owen Anderson | ce4d88a | 2007-09-21 03:53:52 +0000 | [diff] [blame] | 269 | |
| 270 | SmallVector<BasicBlock*, 4> dirtied; |
| 271 | for (DenseMap<BasicBlock*, Value*>::iterator I = cached.begin(), |
| 272 | E = cached.end(); I != E; ++I) |
| 273 | if (I->second == Dirty) |
| 274 | dirtied.push_back(I->first); |
| 275 | |
| 276 | for (SmallVector<BasicBlock*, 4>::iterator I = dirtied.begin(), |
| 277 | E = dirtied.end(); I != E; ++I) { |
| 278 | Instruction* localDep = getDependency(query, 0, *I); |
| 279 | if (localDep != NonLocal) |
| 280 | cached[*I] = localDep; |
| 281 | else { |
| 282 | cached.erase(*I); |
| 283 | nonLocalHelper(query, *I, cached); |
| 284 | } |
| 285 | } |
| 286 | |
| 287 | resp = cached; |
| 288 | |
Owen Anderson | 6bd15ce | 2008-06-01 21:03:52 +0000 | [diff] [blame] | 289 | // Update the reverse non-local dependency cache |
| 290 | for (DenseMap<BasicBlock*, Value*>::iterator I = resp.begin(), E = resp.end(); |
| 291 | I != E; ++I) |
| 292 | reverseDepNonLocal[I->second].insert(query); |
| 293 | |
Owen Anderson | 4d13de4 | 2007-08-16 21:27:05 +0000 | [diff] [blame] | 294 | return; |
Owen Anderson | 7fad7e3 | 2007-09-09 21:43:49 +0000 | [diff] [blame] | 295 | } else |
| 296 | NumUncacheNonlocal++; |
Owen Anderson | 4d13de4 | 2007-08-16 21:27:05 +0000 | [diff] [blame] | 297 | |
Owen Anderson | 7fad7e3 | 2007-09-09 21:43:49 +0000 | [diff] [blame] | 298 | // If not, go ahead and search for non-local deps. |
Owen Anderson | 9066020 | 2007-08-01 22:01:54 +0000 | [diff] [blame] | 299 | nonLocalHelper(query, query->getParent(), resp); |
Owen Anderson | 4d13de4 | 2007-08-16 21:27:05 +0000 | [diff] [blame] | 300 | |
| 301 | // Update the non-local dependency cache |
| 302 | for (DenseMap<BasicBlock*, Value*>::iterator I = resp.begin(), E = resp.end(); |
| 303 | I != E; ++I) { |
| 304 | depGraphNonLocal[query].insert(*I); |
| 305 | reverseDepNonLocal[I->second].insert(query); |
| 306 | } |
Owen Anderson | 4beedbd | 2007-07-24 21:52:37 +0000 | [diff] [blame] | 307 | } |
| 308 | |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 309 | /// getDependency - Return the instruction on which a memory operation |
Dan Gohman | c04575f | 2008-04-10 23:02:38 +0000 | [diff] [blame] | 310 | /// depends. The local parameter indicates if the query should only |
Owen Anderson | 6b278fc | 2007-07-10 17:08:11 +0000 | [diff] [blame] | 311 | /// evaluate dependencies within the same basic block. |
Owen Anderson | 9528f11 | 2007-08-09 04:42:44 +0000 | [diff] [blame] | 312 | Instruction* MemoryDependenceAnalysis::getDependency(Instruction* query, |
Owen Anderson | faac518 | 2007-07-16 21:52:50 +0000 | [diff] [blame] | 313 | Instruction* start, |
Owen Anderson | 4beedbd | 2007-07-24 21:52:37 +0000 | [diff] [blame] | 314 | BasicBlock* block) { |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 315 | // Start looking for dependencies with the queried inst |
| 316 | BasicBlock::iterator QI = query; |
| 317 | |
| 318 | // Check for a cached result |
Owen Anderson | 5fc4aba | 2007-12-08 01:37:09 +0000 | [diff] [blame] | 319 | std::pair<Instruction*, bool>& cachedResult = depGraphLocal[query]; |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 320 | // If we have a _confirmed_ cached entry, return it |
Owen Anderson | 5fc4aba | 2007-12-08 01:37:09 +0000 | [diff] [blame] | 321 | if (!block && !start) { |
| 322 | if (cachedResult.second) |
| 323 | return cachedResult.first; |
| 324 | else if (cachedResult.first && cachedResult.first != NonLocal) |
| 325 | // If we have an unconfirmed cached entry, we can start our search from there |
| 326 | QI = cachedResult.first; |
| 327 | } |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 328 | |
Owen Anderson | faac518 | 2007-07-16 21:52:50 +0000 | [diff] [blame] | 329 | if (start) |
| 330 | QI = start; |
Owen Anderson | 0cd3203 | 2007-07-25 19:57:03 +0000 | [diff] [blame] | 331 | else if (!start && block) |
| 332 | QI = block->end(); |
Owen Anderson | faac518 | 2007-07-16 21:52:50 +0000 | [diff] [blame] | 333 | |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 334 | AliasAnalysis& AA = getAnalysis<AliasAnalysis>(); |
Owen Anderson | 6b278fc | 2007-07-10 17:08:11 +0000 | [diff] [blame] | 335 | TargetData& TD = getAnalysis<TargetData>(); |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 336 | |
| 337 | // Get the pointer value for which dependence will be determined |
| 338 | Value* dependee = 0; |
Owen Anderson | 6b278fc | 2007-07-10 17:08:11 +0000 | [diff] [blame] | 339 | uint64_t dependeeSize = 0; |
Owen Anderson | e314eb3 | 2007-07-10 18:11:42 +0000 | [diff] [blame] | 340 | bool queryIsVolatile = false; |
Owen Anderson | faac518 | 2007-07-16 21:52:50 +0000 | [diff] [blame] | 341 | if (StoreInst* S = dyn_cast<StoreInst>(query)) { |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 342 | dependee = S->getPointerOperand(); |
Duncan Sands | 514ab34 | 2007-11-01 20:53:16 +0000 | [diff] [blame] | 343 | dependeeSize = TD.getTypeStoreSize(S->getOperand(0)->getType()); |
Owen Anderson | e314eb3 | 2007-07-10 18:11:42 +0000 | [diff] [blame] | 344 | queryIsVolatile = S->isVolatile(); |
Owen Anderson | faac518 | 2007-07-16 21:52:50 +0000 | [diff] [blame] | 345 | } else if (LoadInst* L = dyn_cast<LoadInst>(query)) { |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 346 | dependee = L->getPointerOperand(); |
Duncan Sands | 514ab34 | 2007-11-01 20:53:16 +0000 | [diff] [blame] | 347 | dependeeSize = TD.getTypeStoreSize(L->getType()); |
Owen Anderson | e314eb3 | 2007-07-10 18:11:42 +0000 | [diff] [blame] | 348 | queryIsVolatile = L->isVolatile(); |
Owen Anderson | faac518 | 2007-07-16 21:52:50 +0000 | [diff] [blame] | 349 | } else if (VAArgInst* V = dyn_cast<VAArgInst>(query)) { |
Owen Anderson | 06b6e82 | 2007-07-10 18:43:15 +0000 | [diff] [blame] | 350 | dependee = V->getOperand(0); |
Duncan Sands | 514ab34 | 2007-11-01 20:53:16 +0000 | [diff] [blame] | 351 | dependeeSize = TD.getTypeStoreSize(V->getType()); |
Owen Anderson | faac518 | 2007-07-16 21:52:50 +0000 | [diff] [blame] | 352 | } else if (FreeInst* F = dyn_cast<FreeInst>(query)) { |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 353 | dependee = F->getPointerOperand(); |
Owen Anderson | 6b278fc | 2007-07-10 17:08:11 +0000 | [diff] [blame] | 354 | |
| 355 | // FreeInsts erase the entire structure, not just a field |
| 356 | dependeeSize = ~0UL; |
Owen Anderson | faac518 | 2007-07-16 21:52:50 +0000 | [diff] [blame] | 357 | } else if (CallSite::get(query).getInstruction() != 0) |
Owen Anderson | dbbe816 | 2007-08-07 00:33:45 +0000 | [diff] [blame] | 358 | return getCallSiteDependency(CallSite::get(query), start, block); |
Owen Anderson | 5f32320 | 2007-07-10 17:59:22 +0000 | [diff] [blame] | 359 | else if (isa<AllocationInst>(query)) |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 360 | return None; |
Owen Anderson | 7a616a1 | 2007-07-10 17:25:03 +0000 | [diff] [blame] | 361 | else |
Owen Anderson | 6b278fc | 2007-07-10 17:08:11 +0000 | [diff] [blame] | 362 | return None; |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 363 | |
Owen Anderson | 4beedbd | 2007-07-24 21:52:37 +0000 | [diff] [blame] | 364 | BasicBlock::iterator blockBegin = block ? block->begin() |
| 365 | : query->getParent()->begin(); |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 366 | |
Owen Anderson | 642a9e3 | 2007-08-08 22:26:03 +0000 | [diff] [blame] | 367 | // Walk backwards through the basic block, looking for dependencies |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 368 | while (QI != blockBegin) { |
Owen Anderson | 6b278fc | 2007-07-10 17:08:11 +0000 | [diff] [blame] | 369 | --QI; |
| 370 | |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 371 | // If this inst is a memory op, get the pointer it accessed |
| 372 | Value* pointer = 0; |
Owen Anderson | 6b278fc | 2007-07-10 17:08:11 +0000 | [diff] [blame] | 373 | uint64_t pointerSize = 0; |
| 374 | if (StoreInst* S = dyn_cast<StoreInst>(QI)) { |
Owen Anderson | e314eb3 | 2007-07-10 18:11:42 +0000 | [diff] [blame] | 375 | // All volatile loads/stores depend on each other |
| 376 | if (queryIsVolatile && S->isVolatile()) { |
Owen Anderson | dbbe816 | 2007-08-07 00:33:45 +0000 | [diff] [blame] | 377 | if (!start && !block) { |
Owen Anderson | 5fc4aba | 2007-12-08 01:37:09 +0000 | [diff] [blame] | 378 | cachedResult.first = S; |
| 379 | cachedResult.second = true; |
Owen Anderson | dbbe816 | 2007-08-07 00:33:45 +0000 | [diff] [blame] | 380 | reverseDep[S].insert(query); |
Owen Anderson | faac518 | 2007-07-16 21:52:50 +0000 | [diff] [blame] | 381 | } |
| 382 | |
Owen Anderson | e314eb3 | 2007-07-10 18:11:42 +0000 | [diff] [blame] | 383 | return S; |
| 384 | } |
| 385 | |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 386 | pointer = S->getPointerOperand(); |
Duncan Sands | 514ab34 | 2007-11-01 20:53:16 +0000 | [diff] [blame] | 387 | pointerSize = TD.getTypeStoreSize(S->getOperand(0)->getType()); |
Owen Anderson | 6b278fc | 2007-07-10 17:08:11 +0000 | [diff] [blame] | 388 | } else if (LoadInst* L = dyn_cast<LoadInst>(QI)) { |
Owen Anderson | e314eb3 | 2007-07-10 18:11:42 +0000 | [diff] [blame] | 389 | // All volatile loads/stores depend on each other |
| 390 | if (queryIsVolatile && L->isVolatile()) { |
Owen Anderson | dbbe816 | 2007-08-07 00:33:45 +0000 | [diff] [blame] | 391 | if (!start && !block) { |
Owen Anderson | 5fc4aba | 2007-12-08 01:37:09 +0000 | [diff] [blame] | 392 | cachedResult.first = L; |
| 393 | cachedResult.second = true; |
Owen Anderson | dbbe816 | 2007-08-07 00:33:45 +0000 | [diff] [blame] | 394 | reverseDep[L].insert(query); |
Owen Anderson | faac518 | 2007-07-16 21:52:50 +0000 | [diff] [blame] | 395 | } |
| 396 | |
Owen Anderson | e314eb3 | 2007-07-10 18:11:42 +0000 | [diff] [blame] | 397 | return L; |
| 398 | } |
| 399 | |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 400 | pointer = L->getPointerOperand(); |
Duncan Sands | 514ab34 | 2007-11-01 20:53:16 +0000 | [diff] [blame] | 401 | pointerSize = TD.getTypeStoreSize(L->getType()); |
Owen Anderson | 6b278fc | 2007-07-10 17:08:11 +0000 | [diff] [blame] | 402 | } else if (AllocationInst* AI = dyn_cast<AllocationInst>(QI)) { |
| 403 | pointer = AI; |
Owen Anderson | 7a616a1 | 2007-07-10 17:25:03 +0000 | [diff] [blame] | 404 | if (ConstantInt* C = dyn_cast<ConstantInt>(AI->getArraySize())) |
Chris Lattner | 57d4012 | 2008-11-28 21:16:44 +0000 | [diff] [blame] | 405 | pointerSize = C->getZExtValue() * |
Duncan Sands | 514ab34 | 2007-11-01 20:53:16 +0000 | [diff] [blame] | 406 | TD.getABITypeSize(AI->getAllocatedType()); |
Owen Anderson | 6b278fc | 2007-07-10 17:08:11 +0000 | [diff] [blame] | 407 | else |
| 408 | pointerSize = ~0UL; |
Owen Anderson | 06b6e82 | 2007-07-10 18:43:15 +0000 | [diff] [blame] | 409 | } else if (VAArgInst* V = dyn_cast<VAArgInst>(QI)) { |
| 410 | pointer = V->getOperand(0); |
Duncan Sands | 514ab34 | 2007-11-01 20:53:16 +0000 | [diff] [blame] | 411 | pointerSize = TD.getTypeStoreSize(V->getType()); |
Owen Anderson | 6b278fc | 2007-07-10 17:08:11 +0000 | [diff] [blame] | 412 | } else if (FreeInst* F = dyn_cast<FreeInst>(QI)) { |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 413 | pointer = F->getPointerOperand(); |
Owen Anderson | 6b278fc | 2007-07-10 17:08:11 +0000 | [diff] [blame] | 414 | |
| 415 | // FreeInsts erase the entire structure |
| 416 | pointerSize = ~0UL; |
Owen Anderson | 5f32320 | 2007-07-10 17:59:22 +0000 | [diff] [blame] | 417 | } else if (CallSite::get(QI).getInstruction() != 0) { |
Owen Anderson | 80b1f09 | 2007-08-08 22:01:54 +0000 | [diff] [blame] | 418 | // Call insts need special handling. Check if they can modify our pointer |
Owen Anderson | 8f35315 | 2007-08-06 23:26:03 +0000 | [diff] [blame] | 419 | AliasAnalysis::ModRefResult MR = AA.getModRefInfo(CallSite::get(QI), |
| 420 | dependee, dependeeSize); |
| 421 | |
| 422 | if (MR != AliasAnalysis::NoModRef) { |
| 423 | // Loads don't depend on read-only calls |
| 424 | if (isa<LoadInst>(query) && MR == AliasAnalysis::Ref) |
| 425 | continue; |
| 426 | |
Owen Anderson | dbbe816 | 2007-08-07 00:33:45 +0000 | [diff] [blame] | 427 | if (!start && !block) { |
Owen Anderson | 5fc4aba | 2007-12-08 01:37:09 +0000 | [diff] [blame] | 428 | cachedResult.first = QI; |
| 429 | cachedResult.second = true; |
Owen Anderson | dbbe816 | 2007-08-07 00:33:45 +0000 | [diff] [blame] | 430 | reverseDep[QI].insert(query); |
Owen Anderson | faac518 | 2007-07-16 21:52:50 +0000 | [diff] [blame] | 431 | } |
| 432 | |
Owen Anderson | 5f32320 | 2007-07-10 17:59:22 +0000 | [diff] [blame] | 433 | return QI; |
Owen Anderson | 7a616a1 | 2007-07-10 17:25:03 +0000 | [diff] [blame] | 434 | } else { |
| 435 | continue; |
| 436 | } |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 437 | } |
| 438 | |
| 439 | // If we found a pointer, check if it could be the same as our pointer |
| 440 | if (pointer) { |
Owen Anderson | 6b278fc | 2007-07-10 17:08:11 +0000 | [diff] [blame] | 441 | AliasAnalysis::AliasResult R = AA.alias(pointer, pointerSize, |
| 442 | dependee, dependeeSize); |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 443 | |
| 444 | if (R != AliasAnalysis::NoAlias) { |
Owen Anderson | 8f35315 | 2007-08-06 23:26:03 +0000 | [diff] [blame] | 445 | // May-alias loads don't depend on each other |
| 446 | if (isa<LoadInst>(query) && isa<LoadInst>(QI) && |
| 447 | R == AliasAnalysis::MayAlias) |
| 448 | continue; |
| 449 | |
Owen Anderson | dbbe816 | 2007-08-07 00:33:45 +0000 | [diff] [blame] | 450 | if (!start && !block) { |
Owen Anderson | 5fc4aba | 2007-12-08 01:37:09 +0000 | [diff] [blame] | 451 | cachedResult.first = QI; |
| 452 | cachedResult.second = true; |
Owen Anderson | dbbe816 | 2007-08-07 00:33:45 +0000 | [diff] [blame] | 453 | reverseDep[QI].insert(query); |
Owen Anderson | faac518 | 2007-07-16 21:52:50 +0000 | [diff] [blame] | 454 | } |
| 455 | |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 456 | return QI; |
| 457 | } |
| 458 | } |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 459 | } |
| 460 | |
| 461 | // If we found nothing, return the non-local flag |
Owen Anderson | dbbe816 | 2007-08-07 00:33:45 +0000 | [diff] [blame] | 462 | if (!start && !block) { |
Owen Anderson | 5fc4aba | 2007-12-08 01:37:09 +0000 | [diff] [blame] | 463 | cachedResult.first = NonLocal; |
| 464 | cachedResult.second = true; |
Owen Anderson | dbbe816 | 2007-08-07 00:33:45 +0000 | [diff] [blame] | 465 | reverseDep[NonLocal].insert(query); |
Owen Anderson | faac518 | 2007-07-16 21:52:50 +0000 | [diff] [blame] | 466 | } |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 467 | |
| 468 | return NonLocal; |
| 469 | } |
| 470 | |
Owen Anderson | 30b4bd4 | 2008-02-12 21:15:18 +0000 | [diff] [blame] | 471 | /// dropInstruction - Remove an instruction from the analysis, making |
| 472 | /// absolutely conservative assumptions when updating the cache. This is |
| 473 | /// useful, for example when an instruction is changed rather than removed. |
| 474 | void MemoryDependenceAnalysis::dropInstruction(Instruction* drop) { |
| 475 | depMapType::iterator depGraphEntry = depGraphLocal.find(drop); |
| 476 | if (depGraphEntry != depGraphLocal.end()) |
| 477 | reverseDep[depGraphEntry->second.first].erase(drop); |
| 478 | |
| 479 | // Drop dependency information for things that depended on this instr |
| 480 | SmallPtrSet<Instruction*, 4>& set = reverseDep[drop]; |
| 481 | for (SmallPtrSet<Instruction*, 4>::iterator I = set.begin(), E = set.end(); |
| 482 | I != E; ++I) |
| 483 | depGraphLocal.erase(*I); |
| 484 | |
| 485 | depGraphLocal.erase(drop); |
| 486 | reverseDep.erase(drop); |
| 487 | |
| 488 | for (DenseMap<BasicBlock*, Value*>::iterator DI = |
| 489 | depGraphNonLocal[drop].begin(), DE = depGraphNonLocal[drop].end(); |
| 490 | DI != DE; ++DI) |
| 491 | if (DI->second != None) |
| 492 | reverseDepNonLocal[DI->second].erase(drop); |
| 493 | |
| 494 | if (reverseDepNonLocal.count(drop)) { |
| 495 | SmallPtrSet<Instruction*, 4>& set = reverseDepNonLocal[drop]; |
| 496 | for (SmallPtrSet<Instruction*, 4>::iterator I = set.begin(), E = set.end(); |
| 497 | I != E; ++I) |
| 498 | for (DenseMap<BasicBlock*, Value*>::iterator DI = |
| 499 | depGraphNonLocal[*I].begin(), DE = depGraphNonLocal[*I].end(); |
| 500 | DI != DE; ++DI) |
| 501 | if (DI->second == drop) |
| 502 | DI->second = Dirty; |
| 503 | } |
| 504 | |
| 505 | reverseDepNonLocal.erase(drop); |
| 506 | nonLocalDepMapType::iterator I = depGraphNonLocal.find(drop); |
| 507 | if (I != depGraphNonLocal.end()) |
| 508 | depGraphNonLocal.erase(I); |
| 509 | } |
| 510 | |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 511 | /// removeInstruction - Remove an instruction from the dependence analysis, |
| 512 | /// updating the dependence of instructions that previously depended on it. |
Owen Anderson | 642a9e3 | 2007-08-08 22:26:03 +0000 | [diff] [blame] | 513 | /// This method attempts to keep the cache coherent using the reverse map. |
Chris Lattner | 5f589dc | 2008-11-28 22:04:47 +0000 | [diff] [blame] | 514 | void MemoryDependenceAnalysis::removeInstruction(Instruction *RemInst) { |
Chris Lattner | 5f589dc | 2008-11-28 22:04:47 +0000 | [diff] [blame] | 515 | // Walk through the Non-local dependencies, removing this one as the value |
| 516 | // for any cached queries. |
Owen Anderson | 5fc4aba | 2007-12-08 01:37:09 +0000 | [diff] [blame] | 517 | for (DenseMap<BasicBlock*, Value*>::iterator DI = |
Chris Lattner | 5f589dc | 2008-11-28 22:04:47 +0000 | [diff] [blame] | 518 | depGraphNonLocal[RemInst].begin(), DE = depGraphNonLocal[RemInst].end(); |
Owen Anderson | 5fc4aba | 2007-12-08 01:37:09 +0000 | [diff] [blame] | 519 | DI != DE; ++DI) |
| 520 | if (DI->second != None) |
Chris Lattner | 5f589dc | 2008-11-28 22:04:47 +0000 | [diff] [blame] | 521 | reverseDepNonLocal[DI->second].erase(RemInst); |
Owen Anderson | 5fc4aba | 2007-12-08 01:37:09 +0000 | [diff] [blame] | 522 | |
Chris Lattner | baad888 | 2008-11-28 22:28:27 +0000 | [diff] [blame^] | 523 | // Shortly after this, we will look for things that depend on RemInst. In |
| 524 | // order to update these, we'll need a new dependency to base them on. We |
| 525 | // could completely delete any entries that depend on this, but it is better |
| 526 | // to make a more accurate approximation where possible. Compute that better |
| 527 | // approximation if we can. |
| 528 | Instruction *NewDependency = 0; |
| 529 | bool NewDependencyConfirmed = false; |
| 530 | |
Chris Lattner | 5f589dc | 2008-11-28 22:04:47 +0000 | [diff] [blame] | 531 | // If we have a cached local dependence query for this instruction, remove it. |
Chris Lattner | baad888 | 2008-11-28 22:28:27 +0000 | [diff] [blame^] | 532 | // |
| 533 | depMapType::iterator LocalDepEntry = depGraphLocal.find(RemInst); |
| 534 | if (LocalDepEntry != depGraphLocal.end()) { |
| 535 | Instruction *LocalDepInst = LocalDepEntry->second.first; |
| 536 | bool IsConfirmed = LocalDepEntry->second.second; |
Owen Anderson | 9a8ff8c | 2008-01-30 01:24:05 +0000 | [diff] [blame] | 537 | |
Chris Lattner | baad888 | 2008-11-28 22:28:27 +0000 | [diff] [blame^] | 538 | // Remove this local dependency info. |
| 539 | depGraphLocal.erase(LocalDepEntry); |
Chris Lattner | 5f589dc | 2008-11-28 22:04:47 +0000 | [diff] [blame] | 540 | |
Chris Lattner | baad888 | 2008-11-28 22:28:27 +0000 | [diff] [blame^] | 541 | // Remove us from DepInst's reverse set now that the local dep info is gone. |
| 542 | reverseDep[LocalDepInst].erase(RemInst); |
| 543 | |
| 544 | // If we have unconfirmed info, don't trust it. |
| 545 | if (IsConfirmed) { |
| 546 | // If we have a confirmed non-local flag, use it. |
| 547 | if (LocalDepInst == NonLocal || LocalDepInst == None) { |
| 548 | NewDependency = LocalDepInst; |
| 549 | NewDependencyConfirmed = true; |
| 550 | } else { |
| 551 | // If we have dep info for RemInst, set them to it. |
| 552 | NewDependency = next(BasicBlock::iterator(LocalDepInst)); |
| 553 | |
| 554 | // Don't use RI for the new dependency! |
| 555 | if (NewDependency == RemInst) |
| 556 | NewDependency = 0; |
| 557 | } |
David Greene | df46419 | 2007-07-31 20:01:27 +0000 | [diff] [blame] | 558 | } |
Owen Anderson | a8701a6 | 2008-02-05 04:34:03 +0000 | [diff] [blame] | 559 | } |
| 560 | |
Chris Lattner | baad888 | 2008-11-28 22:28:27 +0000 | [diff] [blame^] | 561 | // If we don't already have a local dependency answer for this instruction, |
| 562 | // use the immediate successor of RemInst. We use the successor because |
| 563 | // getDependence starts by checking the immediate predecessor of what is in |
| 564 | // the cache. |
| 565 | if (NewDependency == 0) |
| 566 | NewDependency = next(BasicBlock::iterator(RemInst)); |
| 567 | |
Chris Lattner | 5f589dc | 2008-11-28 22:04:47 +0000 | [diff] [blame] | 568 | SmallPtrSet<Instruction*, 4>& set = reverseDep[RemInst]; |
Owen Anderson | a8701a6 | 2008-02-05 04:34:03 +0000 | [diff] [blame] | 569 | for (SmallPtrSet<Instruction*, 4>::iterator I = set.begin(), E = set.end(); |
| 570 | I != E; ++I) { |
| 571 | // Insert the new dependencies |
| 572 | // Mark it as unconfirmed as long as it is not the non-local flag |
Chris Lattner | baad888 | 2008-11-28 22:28:27 +0000 | [diff] [blame^] | 573 | depGraphLocal[*I] = std::make_pair(NewDependency, NewDependencyConfirmed); |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 574 | } |
Owen Anderson | 4d13de4 | 2007-08-16 21:27:05 +0000 | [diff] [blame] | 575 | |
Chris Lattner | 5f589dc | 2008-11-28 22:04:47 +0000 | [diff] [blame] | 576 | reverseDep.erase(RemInst); |
Owen Anderson | 5fc4aba | 2007-12-08 01:37:09 +0000 | [diff] [blame] | 577 | |
Chris Lattner | 5f589dc | 2008-11-28 22:04:47 +0000 | [diff] [blame] | 578 | if (reverseDepNonLocal.count(RemInst)) { |
| 579 | SmallPtrSet<Instruction*, 4>& set = reverseDepNonLocal[RemInst]; |
Owen Anderson | 4d13de4 | 2007-08-16 21:27:05 +0000 | [diff] [blame] | 580 | for (SmallPtrSet<Instruction*, 4>::iterator I = set.begin(), E = set.end(); |
| 581 | I != E; ++I) |
Owen Anderson | ce4d88a | 2007-09-21 03:53:52 +0000 | [diff] [blame] | 582 | for (DenseMap<BasicBlock*, Value*>::iterator DI = |
| 583 | depGraphNonLocal[*I].begin(), DE = depGraphNonLocal[*I].end(); |
| 584 | DI != DE; ++DI) |
Chris Lattner | 5f589dc | 2008-11-28 22:04:47 +0000 | [diff] [blame] | 585 | if (DI->second == RemInst) |
Owen Anderson | ce4d88a | 2007-09-21 03:53:52 +0000 | [diff] [blame] | 586 | DI->second = Dirty; |
Owen Anderson | 4d13de4 | 2007-08-16 21:27:05 +0000 | [diff] [blame] | 587 | |
Owen Anderson | 4d13de4 | 2007-08-16 21:27:05 +0000 | [diff] [blame] | 588 | } |
Owen Anderson | 5fc4aba | 2007-12-08 01:37:09 +0000 | [diff] [blame] | 589 | |
Chris Lattner | 5f589dc | 2008-11-28 22:04:47 +0000 | [diff] [blame] | 590 | reverseDepNonLocal.erase(RemInst); |
| 591 | depGraphNonLocal.erase(RemInst); |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 592 | |
Chris Lattner | 5f589dc | 2008-11-28 22:04:47 +0000 | [diff] [blame] | 593 | getAnalysis<AliasAnalysis>().deleteValue(RemInst); |
Chris Lattner | 0e575f4 | 2008-11-28 21:45:17 +0000 | [diff] [blame] | 594 | |
Chris Lattner | 5f589dc | 2008-11-28 22:04:47 +0000 | [diff] [blame] | 595 | DEBUG(verifyRemoved(RemInst)); |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 596 | } |