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 | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 44 | // Register this pass... |
Owen Anderson | 776ee1f | 2007-07-10 20:21:08 +0000 | [diff] [blame] | 45 | static RegisterPass<MemoryDependenceAnalysis> X("memdep", |
Chris Lattner | 0e575f4 | 2008-11-28 21:45:17 +0000 | [diff] [blame] | 46 | "Memory Dependence Analysis", false, true); |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 47 | |
Chris Lattner | 0e575f4 | 2008-11-28 21:45:17 +0000 | [diff] [blame] | 48 | /// verifyRemoved - Verify that the specified instruction does not occur |
| 49 | /// in our internal data structures. |
Chris Lattner | 8b589fa | 2008-11-28 21:42:09 +0000 | [diff] [blame] | 50 | void MemoryDependenceAnalysis::verifyRemoved(Instruction *D) const { |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 51 | for (LocalDepMapType::const_iterator I = LocalDeps.begin(), |
| 52 | E = LocalDeps.end(); I != E; ++I) { |
Chris Lattner | 0e575f4 | 2008-11-28 21:45:17 +0000 | [diff] [blame] | 53 | assert(I->first != D && "Inst occurs in data structures"); |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 54 | assert(I->second.first.getPointer() != D && |
| 55 | "Inst occurs in data structures"); |
Owen Anderson | 5fc4aba | 2007-12-08 01:37:09 +0000 | [diff] [blame] | 56 | } |
| 57 | |
Chris Lattner | 8b589fa | 2008-11-28 21:42:09 +0000 | [diff] [blame] | 58 | for (nonLocalDepMapType::const_iterator I = depGraphNonLocal.begin(), |
| 59 | E = depGraphNonLocal.end(); I != E; ++I) { |
Chris Lattner | 0e575f4 | 2008-11-28 21:45:17 +0000 | [diff] [blame] | 60 | assert(I->first != D && "Inst occurs in data structures"); |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 61 | for (DenseMap<BasicBlock*, DepResultTy>::iterator II = I->second.begin(), |
Owen Anderson | d8f34fa | 2008-06-01 20:51:41 +0000 | [diff] [blame] | 62 | EE = I->second.end(); II != EE; ++II) |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 63 | assert(II->second.getPointer() != D && "Inst occurs in data structures"); |
Owen Anderson | 5fc4aba | 2007-12-08 01:37:09 +0000 | [diff] [blame] | 64 | } |
| 65 | |
Chris Lattner | 8b589fa | 2008-11-28 21:42:09 +0000 | [diff] [blame] | 66 | for (reverseDepMapType::const_iterator I = reverseDep.begin(), |
| 67 | E = reverseDep.end(); I != E; ++I) |
| 68 | for (SmallPtrSet<Instruction*, 4>::const_iterator II = I->second.begin(), |
| 69 | EE = I->second.end(); II != EE; ++II) |
Chris Lattner | 0e575f4 | 2008-11-28 21:45:17 +0000 | [diff] [blame] | 70 | assert(*II != D && "Inst occurs in data structures"); |
Owen Anderson | 5fc4aba | 2007-12-08 01:37:09 +0000 | [diff] [blame] | 71 | |
Chris Lattner | 8b589fa | 2008-11-28 21:42:09 +0000 | [diff] [blame] | 72 | for (reverseDepMapType::const_iterator I = reverseDepNonLocal.begin(), |
| 73 | E = reverseDepNonLocal.end(); |
Owen Anderson | 5fc4aba | 2007-12-08 01:37:09 +0000 | [diff] [blame] | 74 | I != E; ++I) |
Chris Lattner | 8b589fa | 2008-11-28 21:42:09 +0000 | [diff] [blame] | 75 | for (SmallPtrSet<Instruction*, 4>::const_iterator II = I->second.begin(), |
| 76 | EE = I->second.end(); II != EE; ++II) |
Chris Lattner | 0e575f4 | 2008-11-28 21:45:17 +0000 | [diff] [blame] | 77 | assert(*II != D && "Inst occurs in data structures"); |
Owen Anderson | 5fc4aba | 2007-12-08 01:37:09 +0000 | [diff] [blame] | 78 | } |
| 79 | |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 80 | /// getAnalysisUsage - Does not modify anything. It uses Alias Analysis. |
| 81 | /// |
| 82 | void MemoryDependenceAnalysis::getAnalysisUsage(AnalysisUsage &AU) const { |
| 83 | AU.setPreservesAll(); |
| 84 | AU.addRequiredTransitive<AliasAnalysis>(); |
| 85 | AU.addRequiredTransitive<TargetData>(); |
| 86 | } |
| 87 | |
Owen Anderson | 642a9e3 | 2007-08-08 22:26:03 +0000 | [diff] [blame] | 88 | /// getCallSiteDependency - Private helper for finding the local dependencies |
| 89 | /// of a call site. |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 90 | MemoryDependenceAnalysis::DepResultTy |
| 91 | MemoryDependenceAnalysis:: |
| 92 | getCallSiteDependency(CallSite C, Instruction *start, BasicBlock *block) { |
| 93 | std::pair<DepResultTy, bool> &cachedResult = LocalDeps[C.getInstruction()]; |
Owen Anderson | 5f32320 | 2007-07-10 17:59:22 +0000 | [diff] [blame] | 94 | AliasAnalysis& AA = getAnalysis<AliasAnalysis>(); |
| 95 | TargetData& TD = getAnalysis<TargetData>(); |
| 96 | BasicBlock::iterator blockBegin = C.getInstruction()->getParent()->begin(); |
| 97 | BasicBlock::iterator QI = C.getInstruction(); |
| 98 | |
Duncan Sands | af8bc26 | 2008-09-11 19:41:10 +0000 | [diff] [blame] | 99 | // If the starting point was specified, use it |
Owen Anderson | dbbe816 | 2007-08-07 00:33:45 +0000 | [diff] [blame] | 100 | if (start) { |
| 101 | QI = start; |
Dan Gohman | 6faaef5 | 2008-03-31 22:08:00 +0000 | [diff] [blame] | 102 | blockBegin = start->getParent()->begin(); |
Owen Anderson | 642a9e3 | 2007-08-08 22:26:03 +0000 | [diff] [blame] | 103 | // 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] | 104 | } else if (!start && block) { |
| 105 | QI = block->end(); |
Dan Gohman | 6faaef5 | 2008-03-31 22:08:00 +0000 | [diff] [blame] | 106 | blockBegin = block->begin(); |
Owen Anderson | dbbe816 | 2007-08-07 00:33:45 +0000 | [diff] [blame] | 107 | } |
| 108 | |
Owen Anderson | 642a9e3 | 2007-08-08 22:26:03 +0000 | [diff] [blame] | 109 | // Walk backwards through the block, looking for dependencies |
Owen Anderson | 5f32320 | 2007-07-10 17:59:22 +0000 | [diff] [blame] | 110 | while (QI != blockBegin) { |
| 111 | --QI; |
| 112 | |
| 113 | // If this inst is a memory op, get the pointer it accessed |
| 114 | Value* pointer = 0; |
| 115 | uint64_t pointerSize = 0; |
| 116 | if (StoreInst* S = dyn_cast<StoreInst>(QI)) { |
| 117 | pointer = S->getPointerOperand(); |
Duncan Sands | 514ab34 | 2007-11-01 20:53:16 +0000 | [diff] [blame] | 118 | pointerSize = TD.getTypeStoreSize(S->getOperand(0)->getType()); |
Owen Anderson | 5f32320 | 2007-07-10 17:59:22 +0000 | [diff] [blame] | 119 | } else if (AllocationInst* AI = dyn_cast<AllocationInst>(QI)) { |
| 120 | pointer = AI; |
| 121 | if (ConstantInt* C = dyn_cast<ConstantInt>(AI->getArraySize())) |
Chris Lattner | 57d4012 | 2008-11-28 21:16:44 +0000 | [diff] [blame] | 122 | pointerSize = C->getZExtValue() * |
Duncan Sands | 514ab34 | 2007-11-01 20:53:16 +0000 | [diff] [blame] | 123 | TD.getABITypeSize(AI->getAllocatedType()); |
Owen Anderson | 5f32320 | 2007-07-10 17:59:22 +0000 | [diff] [blame] | 124 | else |
| 125 | pointerSize = ~0UL; |
Owen Anderson | 06b6e82 | 2007-07-10 18:43:15 +0000 | [diff] [blame] | 126 | } else if (VAArgInst* V = dyn_cast<VAArgInst>(QI)) { |
| 127 | pointer = V->getOperand(0); |
Duncan Sands | 514ab34 | 2007-11-01 20:53:16 +0000 | [diff] [blame] | 128 | pointerSize = TD.getTypeStoreSize(V->getType()); |
Owen Anderson | 5f32320 | 2007-07-10 17:59:22 +0000 | [diff] [blame] | 129 | } else if (FreeInst* F = dyn_cast<FreeInst>(QI)) { |
| 130 | pointer = F->getPointerOperand(); |
| 131 | |
| 132 | // FreeInsts erase the entire structure |
| 133 | pointerSize = ~0UL; |
Owen Anderson | ff5a535 | 2008-05-13 21:25:37 +0000 | [diff] [blame] | 134 | } else if (CallSite::get(QI).getInstruction() != 0) { |
Owen Anderson | 00a6d14 | 2007-11-26 02:26:36 +0000 | [diff] [blame] | 135 | AliasAnalysis::ModRefBehavior result = |
Duncan Sands | dff6710 | 2007-12-01 07:51:45 +0000 | [diff] [blame] | 136 | AA.getModRefBehavior(CallSite::get(QI)); |
Owen Anderson | 241f653 | 2008-04-17 05:36:50 +0000 | [diff] [blame] | 137 | if (result != AliasAnalysis::DoesNotAccessMemory) { |
Owen Anderson | dbbe816 | 2007-08-07 00:33:45 +0000 | [diff] [blame] | 138 | if (!start && !block) { |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 139 | cachedResult.first = DepResultTy(QI, Normal); |
Owen Anderson | 5fc4aba | 2007-12-08 01:37:09 +0000 | [diff] [blame] | 140 | cachedResult.second = true; |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 141 | reverseDep[DepResultTy(QI, Normal)].insert(C.getInstruction()); |
Owen Anderson | dbbe816 | 2007-08-07 00:33:45 +0000 | [diff] [blame] | 142 | } |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 143 | return DepResultTy(QI, Normal); |
Owen Anderson | 5f32320 | 2007-07-10 17:59:22 +0000 | [diff] [blame] | 144 | } else { |
| 145 | continue; |
| 146 | } |
Owen Anderson | 202da14 | 2007-07-10 20:39:07 +0000 | [diff] [blame] | 147 | } else |
| 148 | continue; |
Owen Anderson | 5f32320 | 2007-07-10 17:59:22 +0000 | [diff] [blame] | 149 | |
| 150 | if (AA.getModRefInfo(C, pointer, pointerSize) != AliasAnalysis::NoModRef) { |
Owen Anderson | dbbe816 | 2007-08-07 00:33:45 +0000 | [diff] [blame] | 151 | if (!start && !block) { |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 152 | cachedResult.first = DepResultTy(QI, Normal); |
Owen Anderson | 5fc4aba | 2007-12-08 01:37:09 +0000 | [diff] [blame] | 153 | cachedResult.second = true; |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 154 | reverseDep[DepResultTy(QI, Normal)].insert(C.getInstruction()); |
Owen Anderson | dbbe816 | 2007-08-07 00:33:45 +0000 | [diff] [blame] | 155 | } |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 156 | return DepResultTy(QI, Normal); |
Owen Anderson | 5f32320 | 2007-07-10 17:59:22 +0000 | [diff] [blame] | 157 | } |
| 158 | } |
| 159 | |
| 160 | // No dependence found |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 161 | cachedResult.first = DepResultTy(0, NonLocal); |
Owen Anderson | 5fc4aba | 2007-12-08 01:37:09 +0000 | [diff] [blame] | 162 | cachedResult.second = true; |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 163 | reverseDep[DepResultTy(0, NonLocal)].insert(C.getInstruction()); |
| 164 | return DepResultTy(0, NonLocal); |
Owen Anderson | 5f32320 | 2007-07-10 17:59:22 +0000 | [diff] [blame] | 165 | } |
| 166 | |
Owen Anderson | 642a9e3 | 2007-08-08 22:26:03 +0000 | [diff] [blame] | 167 | /// nonLocalHelper - Private helper used to calculate non-local dependencies |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 168 | /// 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] | 169 | void MemoryDependenceAnalysis::nonLocalHelper(Instruction* query, |
Owen Anderson | 0cd3203 | 2007-07-25 19:57:03 +0000 | [diff] [blame] | 170 | BasicBlock* block, |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 171 | DenseMap<BasicBlock*, DepResultTy> &resp) { |
Owen Anderson | 642a9e3 | 2007-08-08 22:26:03 +0000 | [diff] [blame] | 172 | // Set of blocks that we've already visited in our DFS |
Owen Anderson | 9066020 | 2007-08-01 22:01:54 +0000 | [diff] [blame] | 173 | SmallPtrSet<BasicBlock*, 4> visited; |
Owen Anderson | ce4d88a | 2007-09-21 03:53:52 +0000 | [diff] [blame] | 174 | // If we're updating a dirtied cache entry, we don't need to reprocess |
| 175 | // already computed entries. |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 176 | for (DenseMap<BasicBlock*, DepResultTy>::iterator I = resp.begin(), |
Owen Anderson | ce4d88a | 2007-09-21 03:53:52 +0000 | [diff] [blame] | 177 | E = resp.end(); I != E; ++I) |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 178 | if (I->second.getInt() != Dirty) |
Owen Anderson | ce4d88a | 2007-09-21 03:53:52 +0000 | [diff] [blame] | 179 | visited.insert(I->first); |
| 180 | |
Owen Anderson | 642a9e3 | 2007-08-08 22:26:03 +0000 | [diff] [blame] | 181 | // Current stack of the DFS |
Owen Anderson | 9066020 | 2007-08-01 22:01:54 +0000 | [diff] [blame] | 182 | SmallVector<BasicBlock*, 4> stack; |
Owen Anderson | f062f10 | 2008-04-10 22:13:32 +0000 | [diff] [blame] | 183 | for (pred_iterator PI = pred_begin(block), PE = pred_end(block); |
| 184 | PI != PE; ++PI) |
| 185 | stack.push_back(*PI); |
Owen Anderson | 4beedbd | 2007-07-24 21:52:37 +0000 | [diff] [blame] | 186 | |
Owen Anderson | 642a9e3 | 2007-08-08 22:26:03 +0000 | [diff] [blame] | 187 | // Do a basic DFS |
Owen Anderson | 9066020 | 2007-08-01 22:01:54 +0000 | [diff] [blame] | 188 | while (!stack.empty()) { |
| 189 | BasicBlock* BB = stack.back(); |
| 190 | |
Owen Anderson | 642a9e3 | 2007-08-08 22:26:03 +0000 | [diff] [blame] | 191 | // If we've already visited this block, no need to revist |
Owen Anderson | 1c2763d | 2007-08-02 17:56:05 +0000 | [diff] [blame] | 192 | if (visited.count(BB)) { |
Owen Anderson | 9066020 | 2007-08-01 22:01:54 +0000 | [diff] [blame] | 193 | stack.pop_back(); |
| 194 | continue; |
| 195 | } |
| 196 | |
Owen Anderson | 642a9e3 | 2007-08-08 22:26:03 +0000 | [diff] [blame] | 197 | // If we find a new block with a local dependency for query, |
| 198 | // then we insert the new dependency and backtrack. |
Owen Anderson | 9066020 | 2007-08-01 22:01:54 +0000 | [diff] [blame] | 199 | if (BB != block) { |
Owen Anderson | 1c2763d | 2007-08-02 17:56:05 +0000 | [diff] [blame] | 200 | visited.insert(BB); |
| 201 | |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 202 | DepResultTy localDep = getDependency(query, 0, BB); |
| 203 | if (localDep.getInt() != NonLocal) { |
Owen Anderson | 9528f11 | 2007-08-09 04:42:44 +0000 | [diff] [blame] | 204 | resp.insert(std::make_pair(BB, localDep)); |
Owen Anderson | 1c2763d | 2007-08-02 17:56:05 +0000 | [diff] [blame] | 205 | stack.pop_back(); |
| 206 | |
Owen Anderson | 9066020 | 2007-08-01 22:01:54 +0000 | [diff] [blame] | 207 | continue; |
| 208 | } |
Owen Anderson | 642a9e3 | 2007-08-08 22:26:03 +0000 | [diff] [blame] | 209 | // If we re-encounter the starting block, we still need to search it |
| 210 | // because there might be a dependency in the starting block AFTER |
| 211 | // the position of the query. This is necessary to get loops right. |
Owen Anderson | f062f10 | 2008-04-10 22:13:32 +0000 | [diff] [blame] | 212 | } else if (BB == block) { |
Owen Anderson | 1c2763d | 2007-08-02 17:56:05 +0000 | [diff] [blame] | 213 | visited.insert(BB); |
| 214 | |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 215 | DepResultTy localDep = getDependency(query, 0, BB); |
| 216 | if (localDep != DepResultTy(query, Normal)) |
Owen Anderson | 9528f11 | 2007-08-09 04:42:44 +0000 | [diff] [blame] | 217 | resp.insert(std::make_pair(BB, localDep)); |
Owen Anderson | 1c2763d | 2007-08-02 17:56:05 +0000 | [diff] [blame] | 218 | |
| 219 | stack.pop_back(); |
| 220 | |
| 221 | continue; |
Owen Anderson | 9066020 | 2007-08-01 22:01:54 +0000 | [diff] [blame] | 222 | } |
| 223 | |
Owen Anderson | 642a9e3 | 2007-08-08 22:26:03 +0000 | [diff] [blame] | 224 | // 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] | 225 | // Only do this for blocks with a small number of predecessors. |
Owen Anderson | 9066020 | 2007-08-01 22:01:54 +0000 | [diff] [blame] | 226 | bool predOnStack = false; |
| 227 | bool inserted = false; |
Tanya Lattner | 63aa160 | 2008-02-06 00:54:55 +0000 | [diff] [blame] | 228 | if (std::distance(pred_begin(BB), pred_end(BB)) <= PredLimit) { |
| 229 | for (pred_iterator PI = pred_begin(BB), PE = pred_end(BB); |
| 230 | PI != PE; ++PI) |
| 231 | if (!visited.count(*PI)) { |
| 232 | stack.push_back(*PI); |
| 233 | inserted = true; |
| 234 | } else |
| 235 | predOnStack = true; |
| 236 | } |
Owen Anderson | 9066020 | 2007-08-01 22:01:54 +0000 | [diff] [blame] | 237 | |
Owen Anderson | 642a9e3 | 2007-08-08 22:26:03 +0000 | [diff] [blame] | 238 | // 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] | 239 | if (inserted) |
| 240 | continue; |
Owen Anderson | 642a9e3 | 2007-08-08 22:26:03 +0000 | [diff] [blame] | 241 | // If we didn't insert because we have no predecessors, then this |
| 242 | // query has no dependency at all. |
Owen Anderson | 9066020 | 2007-08-01 22:01:54 +0000 | [diff] [blame] | 243 | else if (!inserted && !predOnStack) { |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 244 | resp.insert(std::make_pair(BB, DepResultTy(0, None))); |
Owen Anderson | 642a9e3 | 2007-08-08 22:26:03 +0000 | [diff] [blame] | 245 | // If we didn't insert because our predecessors are already on the stack, |
| 246 | // then we might still have a dependency, but it will be discovered during |
| 247 | // backtracking. |
Owen Anderson | 9066020 | 2007-08-01 22:01:54 +0000 | [diff] [blame] | 248 | } else if (!inserted && predOnStack){ |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 249 | resp.insert(std::make_pair(BB, DepResultTy(0, NonLocal))); |
Owen Anderson | 9066020 | 2007-08-01 22:01:54 +0000 | [diff] [blame] | 250 | } |
| 251 | |
| 252 | stack.pop_back(); |
Owen Anderson | 4beedbd | 2007-07-24 21:52:37 +0000 | [diff] [blame] | 253 | } |
Owen Anderson | 4beedbd | 2007-07-24 21:52:37 +0000 | [diff] [blame] | 254 | } |
| 255 | |
Owen Anderson | 80b1f09 | 2007-08-08 22:01:54 +0000 | [diff] [blame] | 256 | /// getNonLocalDependency - Fills the passed-in map with the non-local |
| 257 | /// dependencies of the queries. The map will contain NonLocal for |
| 258 | /// blocks between the query and its dependencies. |
Owen Anderson | 9066020 | 2007-08-01 22:01:54 +0000 | [diff] [blame] | 259 | void MemoryDependenceAnalysis::getNonLocalDependency(Instruction* query, |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 260 | DenseMap<BasicBlock*, DepResultTy> &resp) { |
Owen Anderson | 4d13de4 | 2007-08-16 21:27:05 +0000 | [diff] [blame] | 261 | if (depGraphNonLocal.count(query)) { |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 262 | DenseMap<BasicBlock*, DepResultTy> &cached = depGraphNonLocal[query]; |
Owen Anderson | 7fad7e3 | 2007-09-09 21:43:49 +0000 | [diff] [blame] | 263 | NumCacheNonlocal++; |
Owen Anderson | ce4d88a | 2007-09-21 03:53:52 +0000 | [diff] [blame] | 264 | |
| 265 | SmallVector<BasicBlock*, 4> dirtied; |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 266 | for (DenseMap<BasicBlock*, DepResultTy>::iterator I = cached.begin(), |
Owen Anderson | ce4d88a | 2007-09-21 03:53:52 +0000 | [diff] [blame] | 267 | E = cached.end(); I != E; ++I) |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 268 | if (I->second.getInt() == Dirty) |
Owen Anderson | ce4d88a | 2007-09-21 03:53:52 +0000 | [diff] [blame] | 269 | dirtied.push_back(I->first); |
| 270 | |
| 271 | for (SmallVector<BasicBlock*, 4>::iterator I = dirtied.begin(), |
| 272 | E = dirtied.end(); I != E; ++I) { |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 273 | DepResultTy localDep = getDependency(query, 0, *I); |
| 274 | if (localDep.getInt() != NonLocal) |
Owen Anderson | ce4d88a | 2007-09-21 03:53:52 +0000 | [diff] [blame] | 275 | cached[*I] = localDep; |
| 276 | else { |
| 277 | cached.erase(*I); |
| 278 | nonLocalHelper(query, *I, cached); |
| 279 | } |
| 280 | } |
| 281 | |
| 282 | resp = cached; |
| 283 | |
Owen Anderson | 6bd15ce | 2008-06-01 21:03:52 +0000 | [diff] [blame] | 284 | // Update the reverse non-local dependency cache |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 285 | for (DenseMap<BasicBlock*, DepResultTy>::iterator I = resp.begin(), |
| 286 | E = resp.end(); I != E; ++I) |
Owen Anderson | 6bd15ce | 2008-06-01 21:03:52 +0000 | [diff] [blame] | 287 | reverseDepNonLocal[I->second].insert(query); |
| 288 | |
Owen Anderson | 4d13de4 | 2007-08-16 21:27:05 +0000 | [diff] [blame] | 289 | return; |
Owen Anderson | 7fad7e3 | 2007-09-09 21:43:49 +0000 | [diff] [blame] | 290 | } else |
| 291 | NumUncacheNonlocal++; |
Owen Anderson | 4d13de4 | 2007-08-16 21:27:05 +0000 | [diff] [blame] | 292 | |
Owen Anderson | 7fad7e3 | 2007-09-09 21:43:49 +0000 | [diff] [blame] | 293 | // If not, go ahead and search for non-local deps. |
Owen Anderson | 9066020 | 2007-08-01 22:01:54 +0000 | [diff] [blame] | 294 | nonLocalHelper(query, query->getParent(), resp); |
Owen Anderson | 4d13de4 | 2007-08-16 21:27:05 +0000 | [diff] [blame] | 295 | |
| 296 | // Update the non-local dependency cache |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 297 | for (DenseMap<BasicBlock*, DepResultTy>::iterator I = resp.begin(), |
| 298 | E = resp.end(); I != E; ++I) { |
Owen Anderson | 4d13de4 | 2007-08-16 21:27:05 +0000 | [diff] [blame] | 299 | depGraphNonLocal[query].insert(*I); |
| 300 | reverseDepNonLocal[I->second].insert(query); |
| 301 | } |
Owen Anderson | 4beedbd | 2007-07-24 21:52:37 +0000 | [diff] [blame] | 302 | } |
| 303 | |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 304 | /// getDependency - Return the instruction on which a memory operation |
Dan Gohman | c04575f | 2008-04-10 23:02:38 +0000 | [diff] [blame] | 305 | /// depends. The local parameter indicates if the query should only |
Owen Anderson | 6b278fc | 2007-07-10 17:08:11 +0000 | [diff] [blame] | 306 | /// evaluate dependencies within the same basic block. |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 307 | MemoryDependenceAnalysis::DepResultTy |
| 308 | MemoryDependenceAnalysis::getDependency(Instruction *query, |
| 309 | Instruction *start, |
| 310 | BasicBlock *block) { |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 311 | // Start looking for dependencies with the queried inst |
| 312 | BasicBlock::iterator QI = query; |
| 313 | |
| 314 | // Check for a cached result |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 315 | std::pair<DepResultTy, bool>& cachedResult = LocalDeps[query]; |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 316 | // If we have a _confirmed_ cached entry, return it |
Owen Anderson | 5fc4aba | 2007-12-08 01:37:09 +0000 | [diff] [blame] | 317 | if (!block && !start) { |
| 318 | if (cachedResult.second) |
| 319 | return cachedResult.first; |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 320 | else if (cachedResult.first.getInt() == Normal && |
| 321 | cachedResult.first.getPointer()) |
| 322 | // If we have an unconfirmed cached entry, we can start our search from |
| 323 | // it. |
| 324 | QI = cachedResult.first.getPointer(); |
Owen Anderson | 5fc4aba | 2007-12-08 01:37:09 +0000 | [diff] [blame] | 325 | } |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 326 | |
Owen Anderson | faac518 | 2007-07-16 21:52:50 +0000 | [diff] [blame] | 327 | if (start) |
| 328 | QI = start; |
Owen Anderson | 0cd3203 | 2007-07-25 19:57:03 +0000 | [diff] [blame] | 329 | else if (!start && block) |
| 330 | QI = block->end(); |
Owen Anderson | faac518 | 2007-07-16 21:52:50 +0000 | [diff] [blame] | 331 | |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 332 | AliasAnalysis& AA = getAnalysis<AliasAnalysis>(); |
Owen Anderson | 6b278fc | 2007-07-10 17:08:11 +0000 | [diff] [blame] | 333 | TargetData& TD = getAnalysis<TargetData>(); |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 334 | |
| 335 | // Get the pointer value for which dependence will be determined |
| 336 | Value* dependee = 0; |
Owen Anderson | 6b278fc | 2007-07-10 17:08:11 +0000 | [diff] [blame] | 337 | uint64_t dependeeSize = 0; |
Owen Anderson | e314eb3 | 2007-07-10 18:11:42 +0000 | [diff] [blame] | 338 | bool queryIsVolatile = false; |
Owen Anderson | faac518 | 2007-07-16 21:52:50 +0000 | [diff] [blame] | 339 | if (StoreInst* S = dyn_cast<StoreInst>(query)) { |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 340 | dependee = S->getPointerOperand(); |
Duncan Sands | 514ab34 | 2007-11-01 20:53:16 +0000 | [diff] [blame] | 341 | dependeeSize = TD.getTypeStoreSize(S->getOperand(0)->getType()); |
Owen Anderson | e314eb3 | 2007-07-10 18:11:42 +0000 | [diff] [blame] | 342 | queryIsVolatile = S->isVolatile(); |
Owen Anderson | faac518 | 2007-07-16 21:52:50 +0000 | [diff] [blame] | 343 | } else if (LoadInst* L = dyn_cast<LoadInst>(query)) { |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 344 | dependee = L->getPointerOperand(); |
Duncan Sands | 514ab34 | 2007-11-01 20:53:16 +0000 | [diff] [blame] | 345 | dependeeSize = TD.getTypeStoreSize(L->getType()); |
Owen Anderson | e314eb3 | 2007-07-10 18:11:42 +0000 | [diff] [blame] | 346 | queryIsVolatile = L->isVolatile(); |
Owen Anderson | faac518 | 2007-07-16 21:52:50 +0000 | [diff] [blame] | 347 | } else if (VAArgInst* V = dyn_cast<VAArgInst>(query)) { |
Owen Anderson | 06b6e82 | 2007-07-10 18:43:15 +0000 | [diff] [blame] | 348 | dependee = V->getOperand(0); |
Duncan Sands | 514ab34 | 2007-11-01 20:53:16 +0000 | [diff] [blame] | 349 | dependeeSize = TD.getTypeStoreSize(V->getType()); |
Owen Anderson | faac518 | 2007-07-16 21:52:50 +0000 | [diff] [blame] | 350 | } else if (FreeInst* F = dyn_cast<FreeInst>(query)) { |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 351 | dependee = F->getPointerOperand(); |
Owen Anderson | 6b278fc | 2007-07-10 17:08:11 +0000 | [diff] [blame] | 352 | |
| 353 | // FreeInsts erase the entire structure, not just a field |
| 354 | dependeeSize = ~0UL; |
Owen Anderson | faac518 | 2007-07-16 21:52:50 +0000 | [diff] [blame] | 355 | } else if (CallSite::get(query).getInstruction() != 0) |
Owen Anderson | dbbe816 | 2007-08-07 00:33:45 +0000 | [diff] [blame] | 356 | return getCallSiteDependency(CallSite::get(query), start, block); |
Owen Anderson | 5f32320 | 2007-07-10 17:59:22 +0000 | [diff] [blame] | 357 | else if (isa<AllocationInst>(query)) |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 358 | return DepResultTy(0, None); |
Owen Anderson | 7a616a1 | 2007-07-10 17:25:03 +0000 | [diff] [blame] | 359 | else |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 360 | return DepResultTy(0, None); |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 361 | |
Owen Anderson | 4beedbd | 2007-07-24 21:52:37 +0000 | [diff] [blame] | 362 | BasicBlock::iterator blockBegin = block ? block->begin() |
| 363 | : query->getParent()->begin(); |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 364 | |
Owen Anderson | 642a9e3 | 2007-08-08 22:26:03 +0000 | [diff] [blame] | 365 | // Walk backwards through the basic block, looking for dependencies |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 366 | while (QI != blockBegin) { |
Owen Anderson | 6b278fc | 2007-07-10 17:08:11 +0000 | [diff] [blame] | 367 | --QI; |
| 368 | |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 369 | // If this inst is a memory op, get the pointer it accessed |
| 370 | Value* pointer = 0; |
Owen Anderson | 6b278fc | 2007-07-10 17:08:11 +0000 | [diff] [blame] | 371 | uint64_t pointerSize = 0; |
| 372 | if (StoreInst* S = dyn_cast<StoreInst>(QI)) { |
Owen Anderson | e314eb3 | 2007-07-10 18:11:42 +0000 | [diff] [blame] | 373 | // All volatile loads/stores depend on each other |
| 374 | if (queryIsVolatile && S->isVolatile()) { |
Owen Anderson | dbbe816 | 2007-08-07 00:33:45 +0000 | [diff] [blame] | 375 | if (!start && !block) { |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 376 | cachedResult.first = DepResultTy(S, Normal); |
Owen Anderson | 5fc4aba | 2007-12-08 01:37:09 +0000 | [diff] [blame] | 377 | cachedResult.second = true; |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 378 | reverseDep[DepResultTy(S, Normal)].insert(query); |
Owen Anderson | faac518 | 2007-07-16 21:52:50 +0000 | [diff] [blame] | 379 | } |
| 380 | |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 381 | return DepResultTy(S, Normal); |
Owen Anderson | e314eb3 | 2007-07-10 18:11:42 +0000 | [diff] [blame] | 382 | } |
| 383 | |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 384 | pointer = S->getPointerOperand(); |
Duncan Sands | 514ab34 | 2007-11-01 20:53:16 +0000 | [diff] [blame] | 385 | pointerSize = TD.getTypeStoreSize(S->getOperand(0)->getType()); |
Owen Anderson | 6b278fc | 2007-07-10 17:08:11 +0000 | [diff] [blame] | 386 | } else if (LoadInst* L = dyn_cast<LoadInst>(QI)) { |
Owen Anderson | e314eb3 | 2007-07-10 18:11:42 +0000 | [diff] [blame] | 387 | // All volatile loads/stores depend on each other |
| 388 | if (queryIsVolatile && L->isVolatile()) { |
Owen Anderson | dbbe816 | 2007-08-07 00:33:45 +0000 | [diff] [blame] | 389 | if (!start && !block) { |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 390 | cachedResult.first = DepResultTy(L, Normal); |
Owen Anderson | 5fc4aba | 2007-12-08 01:37:09 +0000 | [diff] [blame] | 391 | cachedResult.second = true; |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 392 | reverseDep[DepResultTy(L, Normal)].insert(query); |
Owen Anderson | faac518 | 2007-07-16 21:52:50 +0000 | [diff] [blame] | 393 | } |
| 394 | |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 395 | return DepResultTy(L, Normal); |
Owen Anderson | e314eb3 | 2007-07-10 18:11:42 +0000 | [diff] [blame] | 396 | } |
| 397 | |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 398 | pointer = L->getPointerOperand(); |
Duncan Sands | 514ab34 | 2007-11-01 20:53:16 +0000 | [diff] [blame] | 399 | pointerSize = TD.getTypeStoreSize(L->getType()); |
Owen Anderson | 6b278fc | 2007-07-10 17:08:11 +0000 | [diff] [blame] | 400 | } else if (AllocationInst* AI = dyn_cast<AllocationInst>(QI)) { |
| 401 | pointer = AI; |
Owen Anderson | 7a616a1 | 2007-07-10 17:25:03 +0000 | [diff] [blame] | 402 | if (ConstantInt* C = dyn_cast<ConstantInt>(AI->getArraySize())) |
Chris Lattner | 57d4012 | 2008-11-28 21:16:44 +0000 | [diff] [blame] | 403 | pointerSize = C->getZExtValue() * |
Duncan Sands | 514ab34 | 2007-11-01 20:53:16 +0000 | [diff] [blame] | 404 | TD.getABITypeSize(AI->getAllocatedType()); |
Owen Anderson | 6b278fc | 2007-07-10 17:08:11 +0000 | [diff] [blame] | 405 | else |
| 406 | pointerSize = ~0UL; |
Owen Anderson | 06b6e82 | 2007-07-10 18:43:15 +0000 | [diff] [blame] | 407 | } else if (VAArgInst* V = dyn_cast<VAArgInst>(QI)) { |
| 408 | pointer = V->getOperand(0); |
Duncan Sands | 514ab34 | 2007-11-01 20:53:16 +0000 | [diff] [blame] | 409 | pointerSize = TD.getTypeStoreSize(V->getType()); |
Owen Anderson | 6b278fc | 2007-07-10 17:08:11 +0000 | [diff] [blame] | 410 | } else if (FreeInst* F = dyn_cast<FreeInst>(QI)) { |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 411 | pointer = F->getPointerOperand(); |
Owen Anderson | 6b278fc | 2007-07-10 17:08:11 +0000 | [diff] [blame] | 412 | |
| 413 | // FreeInsts erase the entire structure |
| 414 | pointerSize = ~0UL; |
Owen Anderson | 5f32320 | 2007-07-10 17:59:22 +0000 | [diff] [blame] | 415 | } else if (CallSite::get(QI).getInstruction() != 0) { |
Owen Anderson | 80b1f09 | 2007-08-08 22:01:54 +0000 | [diff] [blame] | 416 | // Call insts need special handling. Check if they can modify our pointer |
Owen Anderson | 8f35315 | 2007-08-06 23:26:03 +0000 | [diff] [blame] | 417 | AliasAnalysis::ModRefResult MR = AA.getModRefInfo(CallSite::get(QI), |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 418 | dependee, dependeeSize); |
Owen Anderson | 8f35315 | 2007-08-06 23:26:03 +0000 | [diff] [blame] | 419 | |
| 420 | if (MR != AliasAnalysis::NoModRef) { |
| 421 | // Loads don't depend on read-only calls |
| 422 | if (isa<LoadInst>(query) && MR == AliasAnalysis::Ref) |
| 423 | continue; |
| 424 | |
Owen Anderson | dbbe816 | 2007-08-07 00:33:45 +0000 | [diff] [blame] | 425 | if (!start && !block) { |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 426 | cachedResult.first = DepResultTy(QI, Normal); |
Owen Anderson | 5fc4aba | 2007-12-08 01:37:09 +0000 | [diff] [blame] | 427 | cachedResult.second = true; |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 428 | reverseDep[DepResultTy(QI, Normal)].insert(query); |
Owen Anderson | faac518 | 2007-07-16 21:52:50 +0000 | [diff] [blame] | 429 | } |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 430 | return DepResultTy(QI, Normal); |
Owen Anderson | 7a616a1 | 2007-07-10 17:25:03 +0000 | [diff] [blame] | 431 | } else { |
| 432 | continue; |
| 433 | } |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 434 | } |
| 435 | |
| 436 | // If we found a pointer, check if it could be the same as our pointer |
| 437 | if (pointer) { |
Owen Anderson | 6b278fc | 2007-07-10 17:08:11 +0000 | [diff] [blame] | 438 | AliasAnalysis::AliasResult R = AA.alias(pointer, pointerSize, |
| 439 | dependee, dependeeSize); |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 440 | |
| 441 | if (R != AliasAnalysis::NoAlias) { |
Owen Anderson | 8f35315 | 2007-08-06 23:26:03 +0000 | [diff] [blame] | 442 | // May-alias loads don't depend on each other |
| 443 | if (isa<LoadInst>(query) && isa<LoadInst>(QI) && |
| 444 | R == AliasAnalysis::MayAlias) |
| 445 | continue; |
| 446 | |
Owen Anderson | dbbe816 | 2007-08-07 00:33:45 +0000 | [diff] [blame] | 447 | if (!start && !block) { |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 448 | cachedResult.first = DepResultTy(QI, Normal); |
Owen Anderson | 5fc4aba | 2007-12-08 01:37:09 +0000 | [diff] [blame] | 449 | cachedResult.second = true; |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 450 | reverseDep[DepResultTy(QI, Normal)].insert(query); |
Owen Anderson | faac518 | 2007-07-16 21:52:50 +0000 | [diff] [blame] | 451 | } |
| 452 | |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 453 | return DepResultTy(QI, Normal); |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 454 | } |
| 455 | } |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 456 | } |
| 457 | |
| 458 | // If we found nothing, return the non-local flag |
Owen Anderson | dbbe816 | 2007-08-07 00:33:45 +0000 | [diff] [blame] | 459 | if (!start && !block) { |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 460 | cachedResult.first = DepResultTy(0, NonLocal); |
Owen Anderson | 5fc4aba | 2007-12-08 01:37:09 +0000 | [diff] [blame] | 461 | cachedResult.second = true; |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 462 | reverseDep[DepResultTy(0, NonLocal)].insert(query); |
Owen Anderson | faac518 | 2007-07-16 21:52:50 +0000 | [diff] [blame] | 463 | } |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 464 | |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 465 | return DepResultTy(0, NonLocal); |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 466 | } |
| 467 | |
Owen Anderson | 30b4bd4 | 2008-02-12 21:15:18 +0000 | [diff] [blame] | 468 | /// dropInstruction - Remove an instruction from the analysis, making |
| 469 | /// absolutely conservative assumptions when updating the cache. This is |
| 470 | /// useful, for example when an instruction is changed rather than removed. |
| 471 | void MemoryDependenceAnalysis::dropInstruction(Instruction* drop) { |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 472 | LocalDepMapType::iterator depGraphEntry = LocalDeps.find(drop); |
| 473 | if (depGraphEntry != LocalDeps.end()) |
Owen Anderson | 30b4bd4 | 2008-02-12 21:15:18 +0000 | [diff] [blame] | 474 | reverseDep[depGraphEntry->second.first].erase(drop); |
| 475 | |
| 476 | // Drop dependency information for things that depended on this instr |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 477 | SmallPtrSet<Instruction*, 4>& set = reverseDep[DepResultTy(drop, Normal)]; |
Owen Anderson | 30b4bd4 | 2008-02-12 21:15:18 +0000 | [diff] [blame] | 478 | for (SmallPtrSet<Instruction*, 4>::iterator I = set.begin(), E = set.end(); |
| 479 | I != E; ++I) |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 480 | LocalDeps.erase(*I); |
Owen Anderson | 30b4bd4 | 2008-02-12 21:15:18 +0000 | [diff] [blame] | 481 | |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 482 | LocalDeps.erase(drop); |
| 483 | reverseDep.erase(DepResultTy(drop, Normal)); |
Owen Anderson | 30b4bd4 | 2008-02-12 21:15:18 +0000 | [diff] [blame] | 484 | |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 485 | for (DenseMap<BasicBlock*, DepResultTy>::iterator DI = |
| 486 | depGraphNonLocal[drop].begin(), DE = depGraphNonLocal[drop].end(); |
Owen Anderson | 30b4bd4 | 2008-02-12 21:15:18 +0000 | [diff] [blame] | 487 | DI != DE; ++DI) |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 488 | if (DI->second.getInt() != None) |
Owen Anderson | 30b4bd4 | 2008-02-12 21:15:18 +0000 | [diff] [blame] | 489 | reverseDepNonLocal[DI->second].erase(drop); |
| 490 | |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 491 | if (reverseDepNonLocal.count(DepResultTy(drop, Normal))) { |
| 492 | SmallPtrSet<Instruction*, 4>& set = |
| 493 | reverseDepNonLocal[DepResultTy(drop, Normal)]; |
Owen Anderson | 30b4bd4 | 2008-02-12 21:15:18 +0000 | [diff] [blame] | 494 | for (SmallPtrSet<Instruction*, 4>::iterator I = set.begin(), E = set.end(); |
| 495 | I != E; ++I) |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 496 | for (DenseMap<BasicBlock*, DepResultTy>::iterator DI = |
Owen Anderson | 30b4bd4 | 2008-02-12 21:15:18 +0000 | [diff] [blame] | 497 | depGraphNonLocal[*I].begin(), DE = depGraphNonLocal[*I].end(); |
| 498 | DI != DE; ++DI) |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 499 | if (DI->second == DepResultTy(drop, Normal)) |
| 500 | DI->second = DepResultTy(0, Dirty); |
Owen Anderson | 30b4bd4 | 2008-02-12 21:15:18 +0000 | [diff] [blame] | 501 | } |
| 502 | |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 503 | reverseDepNonLocal.erase(DepResultTy(drop, Normal)); |
| 504 | depGraphNonLocal.erase(drop); |
Owen Anderson | 30b4bd4 | 2008-02-12 21:15:18 +0000 | [diff] [blame] | 505 | } |
| 506 | |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 507 | /// removeInstruction - Remove an instruction from the dependence analysis, |
| 508 | /// updating the dependence of instructions that previously depended on it. |
Owen Anderson | 642a9e3 | 2007-08-08 22:26:03 +0000 | [diff] [blame] | 509 | /// This method attempts to keep the cache coherent using the reverse map. |
Chris Lattner | 5f589dc | 2008-11-28 22:04:47 +0000 | [diff] [blame] | 510 | void MemoryDependenceAnalysis::removeInstruction(Instruction *RemInst) { |
Chris Lattner | 5f589dc | 2008-11-28 22:04:47 +0000 | [diff] [blame] | 511 | // Walk through the Non-local dependencies, removing this one as the value |
| 512 | // for any cached queries. |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 513 | for (DenseMap<BasicBlock*, DepResultTy>::iterator DI = |
Chris Lattner | 5f589dc | 2008-11-28 22:04:47 +0000 | [diff] [blame] | 514 | depGraphNonLocal[RemInst].begin(), DE = depGraphNonLocal[RemInst].end(); |
Owen Anderson | 5fc4aba | 2007-12-08 01:37:09 +0000 | [diff] [blame] | 515 | DI != DE; ++DI) |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 516 | if (DI->second.getInt() != None) |
Chris Lattner | 5f589dc | 2008-11-28 22:04:47 +0000 | [diff] [blame] | 517 | reverseDepNonLocal[DI->second].erase(RemInst); |
Owen Anderson | 5fc4aba | 2007-12-08 01:37:09 +0000 | [diff] [blame] | 518 | |
Chris Lattner | baad888 | 2008-11-28 22:28:27 +0000 | [diff] [blame] | 519 | // Shortly after this, we will look for things that depend on RemInst. In |
| 520 | // order to update these, we'll need a new dependency to base them on. We |
| 521 | // could completely delete any entries that depend on this, but it is better |
| 522 | // to make a more accurate approximation where possible. Compute that better |
| 523 | // approximation if we can. |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 524 | DepResultTy NewDependency; |
Chris Lattner | baad888 | 2008-11-28 22:28:27 +0000 | [diff] [blame] | 525 | bool NewDependencyConfirmed = false; |
| 526 | |
Chris Lattner | 5f589dc | 2008-11-28 22:04:47 +0000 | [diff] [blame] | 527 | // 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] | 528 | // |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 529 | LocalDepMapType::iterator LocalDepEntry = LocalDeps.find(RemInst); |
| 530 | if (LocalDepEntry != LocalDeps.end()) { |
| 531 | DepResultTy LocalDep = LocalDepEntry->second.first; |
Chris Lattner | baad888 | 2008-11-28 22:28:27 +0000 | [diff] [blame] | 532 | bool IsConfirmed = LocalDepEntry->second.second; |
Owen Anderson | 9a8ff8c | 2008-01-30 01:24:05 +0000 | [diff] [blame] | 533 | |
Chris Lattner | baad888 | 2008-11-28 22:28:27 +0000 | [diff] [blame] | 534 | // Remove this local dependency info. |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 535 | LocalDeps.erase(LocalDepEntry); |
Chris Lattner | 5f589dc | 2008-11-28 22:04:47 +0000 | [diff] [blame] | 536 | |
Chris Lattner | baad888 | 2008-11-28 22:28:27 +0000 | [diff] [blame] | 537 | // Remove us from DepInst's reverse set now that the local dep info is gone. |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 538 | reverseDep[LocalDep].erase(RemInst); |
Chris Lattner | baad888 | 2008-11-28 22:28:27 +0000 | [diff] [blame] | 539 | |
| 540 | // If we have unconfirmed info, don't trust it. |
| 541 | if (IsConfirmed) { |
| 542 | // If we have a confirmed non-local flag, use it. |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 543 | if (LocalDep.getInt() == NonLocal || LocalDep.getInt() == None) { |
Chris Lattner | d3d12ec | 2008-11-28 22:51:08 +0000 | [diff] [blame] | 544 | // The only time this dependency is confirmed is if it is non-local. |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 545 | NewDependency = LocalDep; |
Chris Lattner | baad888 | 2008-11-28 22:28:27 +0000 | [diff] [blame] | 546 | NewDependencyConfirmed = true; |
| 547 | } else { |
| 548 | // If we have dep info for RemInst, set them to it. |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 549 | Instruction *NDI = next(BasicBlock::iterator(LocalDep.getPointer())); |
| 550 | if (NDI != RemInst) // Don't use RemInst for the new dependency! |
| 551 | NewDependency = DepResultTy(NDI, Normal); |
Chris Lattner | baad888 | 2008-11-28 22:28:27 +0000 | [diff] [blame] | 552 | } |
David Greene | df46419 | 2007-07-31 20:01:27 +0000 | [diff] [blame] | 553 | } |
Owen Anderson | a8701a6 | 2008-02-05 04:34:03 +0000 | [diff] [blame] | 554 | } |
| 555 | |
Chris Lattner | baad888 | 2008-11-28 22:28:27 +0000 | [diff] [blame] | 556 | // If we don't already have a local dependency answer for this instruction, |
| 557 | // use the immediate successor of RemInst. We use the successor because |
| 558 | // getDependence starts by checking the immediate predecessor of what is in |
| 559 | // the cache. |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 560 | if (NewDependency == DepResultTy(0, Normal)) |
| 561 | NewDependency = DepResultTy(next(BasicBlock::iterator(RemInst)), Normal); |
Chris Lattner | baad888 | 2008-11-28 22:28:27 +0000 | [diff] [blame] | 562 | |
Chris Lattner | d3d12ec | 2008-11-28 22:51:08 +0000 | [diff] [blame] | 563 | // Loop over all of the things that depend on the instruction we're removing. |
| 564 | // |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 565 | reverseDepMapType::iterator ReverseDepIt = |
| 566 | reverseDep.find(DepResultTy(RemInst, Normal)); |
Chris Lattner | d3d12ec | 2008-11-28 22:51:08 +0000 | [diff] [blame] | 567 | if (ReverseDepIt != reverseDep.end()) { |
| 568 | SmallPtrSet<Instruction*, 4> &ReverseDeps = ReverseDepIt->second; |
| 569 | for (SmallPtrSet<Instruction*, 4>::iterator I = ReverseDeps.begin(), |
| 570 | E = ReverseDeps.end(); I != E; ++I) { |
| 571 | Instruction *InstDependingOnRemInst = *I; |
| 572 | |
| 573 | // If we thought the instruction depended on itself (possible for |
| 574 | // unconfirmed dependencies) ignore the update. |
| 575 | if (InstDependingOnRemInst == RemInst) continue; |
| 576 | |
| 577 | // Insert the new dependencies. |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 578 | LocalDeps[InstDependingOnRemInst] = |
Chris Lattner | d3d12ec | 2008-11-28 22:51:08 +0000 | [diff] [blame] | 579 | std::make_pair(NewDependency, NewDependencyConfirmed); |
| 580 | |
| 581 | // If our NewDependency is an instruction, make sure to remember that new |
| 582 | // things depend on it. |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 583 | // FIXME: Just insert all deps! |
| 584 | if (NewDependency.getInt() != NonLocal && NewDependency.getInt() != None) |
Chris Lattner | d3d12ec | 2008-11-28 22:51:08 +0000 | [diff] [blame] | 585 | reverseDep[NewDependency].insert(InstDependingOnRemInst); |
| 586 | } |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 587 | reverseDep.erase(DepResultTy(RemInst, Normal)); |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 588 | } |
Owen Anderson | 4d13de4 | 2007-08-16 21:27:05 +0000 | [diff] [blame] | 589 | |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 590 | ReverseDepIt = reverseDepNonLocal.find(DepResultTy(RemInst, Normal)); |
Chris Lattner | d3d12ec | 2008-11-28 22:51:08 +0000 | [diff] [blame] | 591 | if (ReverseDepIt != reverseDepNonLocal.end()) { |
| 592 | SmallPtrSet<Instruction*, 4>& set = ReverseDepIt->second; |
Owen Anderson | 4d13de4 | 2007-08-16 21:27:05 +0000 | [diff] [blame] | 593 | for (SmallPtrSet<Instruction*, 4>::iterator I = set.begin(), E = set.end(); |
| 594 | I != E; ++I) |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 595 | for (DenseMap<BasicBlock*, DepResultTy>::iterator DI = |
Owen Anderson | ce4d88a | 2007-09-21 03:53:52 +0000 | [diff] [blame] | 596 | depGraphNonLocal[*I].begin(), DE = depGraphNonLocal[*I].end(); |
| 597 | DI != DE; ++DI) |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame^] | 598 | if (DI->second == DepResultTy(RemInst, Normal)) |
| 599 | DI->second = DepResultTy(0, Dirty); |
| 600 | reverseDepNonLocal.erase(ReverseDepIt); |
Owen Anderson | 4d13de4 | 2007-08-16 21:27:05 +0000 | [diff] [blame] | 601 | } |
Owen Anderson | 5fc4aba | 2007-12-08 01:37:09 +0000 | [diff] [blame] | 602 | |
Chris Lattner | 5f589dc | 2008-11-28 22:04:47 +0000 | [diff] [blame] | 603 | depGraphNonLocal.erase(RemInst); |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 604 | |
Chris Lattner | 5f589dc | 2008-11-28 22:04:47 +0000 | [diff] [blame] | 605 | getAnalysis<AliasAnalysis>().deleteValue(RemInst); |
Chris Lattner | 0e575f4 | 2008-11-28 21:45:17 +0000 | [diff] [blame] | 606 | |
Chris Lattner | 5f589dc | 2008-11-28 22:04:47 +0000 | [diff] [blame] | 607 | DEBUG(verifyRemoved(RemInst)); |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 608 | } |