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" |
| 19 | #include "llvm/Instructions.h" |
Owen Anderson | f6cec85 | 2009-03-09 05:12:38 +0000 | [diff] [blame] | 20 | #include "llvm/IntrinsicInst.h" |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 21 | #include "llvm/Function.h" |
| 22 | #include "llvm/Analysis/AliasAnalysis.h" |
Victor Hernandez | f006b18 | 2009-10-27 20:05:49 +0000 | [diff] [blame] | 23 | #include "llvm/Analysis/MemoryBuiltins.h" |
Chris Lattner | baad888 | 2008-11-28 22:28:27 +0000 | [diff] [blame] | 24 | #include "llvm/ADT/Statistic.h" |
Duncan Sands | 7050f3d | 2008-12-10 09:38:36 +0000 | [diff] [blame] | 25 | #include "llvm/ADT/STLExtras.h" |
Chris Lattner | 4012fdd | 2008-12-09 06:28:49 +0000 | [diff] [blame] | 26 | #include "llvm/Support/PredIteratorCache.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 | using namespace llvm; |
| 29 | |
Chris Lattner | bf145d6 | 2008-12-01 01:15:42 +0000 | [diff] [blame] | 30 | STATISTIC(NumCacheNonLocal, "Number of fully cached non-local responses"); |
| 31 | STATISTIC(NumCacheDirtyNonLocal, "Number of dirty cached non-local responses"); |
Chris Lattner | 0ec48dd | 2008-11-29 22:02:15 +0000 | [diff] [blame] | 32 | STATISTIC(NumUncacheNonLocal, "Number of uncached non-local responses"); |
Chris Lattner | 6290f5c | 2008-12-07 08:50:20 +0000 | [diff] [blame] | 33 | |
| 34 | STATISTIC(NumCacheNonLocalPtr, |
| 35 | "Number of fully cached non-local ptr responses"); |
| 36 | STATISTIC(NumCacheDirtyNonLocalPtr, |
| 37 | "Number of cached, but dirty, non-local ptr responses"); |
| 38 | STATISTIC(NumUncacheNonLocalPtr, |
| 39 | "Number of uncached non-local ptr responses"); |
Chris Lattner | 11dcd8d | 2008-12-08 07:31:50 +0000 | [diff] [blame] | 40 | STATISTIC(NumCacheCompleteNonLocalPtr, |
| 41 | "Number of block queries that were completely cached"); |
Chris Lattner | 6290f5c | 2008-12-07 08:50:20 +0000 | [diff] [blame] | 42 | |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 43 | char MemoryDependenceAnalysis::ID = 0; |
| 44 | |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 45 | // Register this pass... |
Owen Anderson | 776ee1f | 2007-07-10 20:21:08 +0000 | [diff] [blame] | 46 | static RegisterPass<MemoryDependenceAnalysis> X("memdep", |
Chris Lattner | 0e575f4 | 2008-11-28 21:45:17 +0000 | [diff] [blame] | 47 | "Memory Dependence Analysis", false, true); |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 48 | |
Chris Lattner | 4012fdd | 2008-12-09 06:28:49 +0000 | [diff] [blame] | 49 | MemoryDependenceAnalysis::MemoryDependenceAnalysis() |
| 50 | : FunctionPass(&ID), PredCache(0) { |
| 51 | } |
| 52 | MemoryDependenceAnalysis::~MemoryDependenceAnalysis() { |
| 53 | } |
| 54 | |
| 55 | /// Clean up memory in between runs |
| 56 | void MemoryDependenceAnalysis::releaseMemory() { |
| 57 | LocalDeps.clear(); |
| 58 | NonLocalDeps.clear(); |
| 59 | NonLocalPointerDeps.clear(); |
| 60 | ReverseLocalDeps.clear(); |
| 61 | ReverseNonLocalDeps.clear(); |
| 62 | ReverseNonLocalPtrDeps.clear(); |
| 63 | PredCache->clear(); |
| 64 | } |
| 65 | |
| 66 | |
| 67 | |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 68 | /// getAnalysisUsage - Does not modify anything. It uses Alias Analysis. |
| 69 | /// |
| 70 | void MemoryDependenceAnalysis::getAnalysisUsage(AnalysisUsage &AU) const { |
| 71 | AU.setPreservesAll(); |
| 72 | AU.addRequiredTransitive<AliasAnalysis>(); |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 73 | } |
| 74 | |
Chris Lattner | d777d40 | 2008-11-30 19:24:31 +0000 | [diff] [blame] | 75 | bool MemoryDependenceAnalysis::runOnFunction(Function &) { |
| 76 | AA = &getAnalysis<AliasAnalysis>(); |
Chris Lattner | 4012fdd | 2008-12-09 06:28:49 +0000 | [diff] [blame] | 77 | if (PredCache == 0) |
| 78 | PredCache.reset(new PredIteratorCache()); |
Chris Lattner | d777d40 | 2008-11-30 19:24:31 +0000 | [diff] [blame] | 79 | return false; |
| 80 | } |
| 81 | |
Chris Lattner | d44745d | 2008-12-07 18:39:13 +0000 | [diff] [blame] | 82 | /// RemoveFromReverseMap - This is a helper function that removes Val from |
| 83 | /// 'Inst's set in ReverseMap. If the set becomes empty, remove Inst's entry. |
| 84 | template <typename KeyTy> |
| 85 | static void RemoveFromReverseMap(DenseMap<Instruction*, |
Chris Lattner | 6a0dcc1 | 2009-03-29 00:24:04 +0000 | [diff] [blame] | 86 | SmallPtrSet<KeyTy, 4> > &ReverseMap, |
| 87 | Instruction *Inst, KeyTy Val) { |
| 88 | typename DenseMap<Instruction*, SmallPtrSet<KeyTy, 4> >::iterator |
Chris Lattner | d44745d | 2008-12-07 18:39:13 +0000 | [diff] [blame] | 89 | InstIt = ReverseMap.find(Inst); |
| 90 | assert(InstIt != ReverseMap.end() && "Reverse map out of sync?"); |
| 91 | bool Found = InstIt->second.erase(Val); |
| 92 | assert(Found && "Invalid reverse map!"); Found=Found; |
| 93 | if (InstIt->second.empty()) |
| 94 | ReverseMap.erase(InstIt); |
| 95 | } |
| 96 | |
Chris Lattner | bf145d6 | 2008-12-01 01:15:42 +0000 | [diff] [blame] | 97 | |
Chris Lattner | 8ef57c5 | 2008-12-07 00:35:51 +0000 | [diff] [blame] | 98 | /// getCallSiteDependencyFrom - Private helper for finding the local |
| 99 | /// dependencies of a call site. |
Chris Lattner | fd3dcbe | 2008-11-30 23:17:19 +0000 | [diff] [blame] | 100 | MemDepResult MemoryDependenceAnalysis:: |
Chris Lattner | 20d6f09 | 2008-12-09 21:19:42 +0000 | [diff] [blame] | 101 | getCallSiteDependencyFrom(CallSite CS, bool isReadOnlyCall, |
| 102 | BasicBlock::iterator ScanIt, BasicBlock *BB) { |
Owen Anderson | 642a9e3 | 2007-08-08 22:26:03 +0000 | [diff] [blame] | 103 | // Walk backwards through the block, looking for dependencies |
Chris Lattner | 5391a1d | 2008-11-29 03:47:00 +0000 | [diff] [blame] | 104 | while (ScanIt != BB->begin()) { |
| 105 | Instruction *Inst = --ScanIt; |
Owen Anderson | 5f32320 | 2007-07-10 17:59:22 +0000 | [diff] [blame] | 106 | |
| 107 | // If this inst is a memory op, get the pointer it accessed |
Chris Lattner | 00314b3 | 2008-11-29 09:15:21 +0000 | [diff] [blame] | 108 | Value *Pointer = 0; |
| 109 | uint64_t PointerSize = 0; |
| 110 | if (StoreInst *S = dyn_cast<StoreInst>(Inst)) { |
| 111 | Pointer = S->getPointerOperand(); |
Dan Gohman | f581213 | 2009-07-31 20:53:12 +0000 | [diff] [blame] | 112 | PointerSize = AA->getTypeStoreSize(S->getOperand(0)->getType()); |
Chris Lattner | 00314b3 | 2008-11-29 09:15:21 +0000 | [diff] [blame] | 113 | } else if (VAArgInst *V = dyn_cast<VAArgInst>(Inst)) { |
| 114 | Pointer = V->getOperand(0); |
Dan Gohman | f581213 | 2009-07-31 20:53:12 +0000 | [diff] [blame] | 115 | PointerSize = AA->getTypeStoreSize(V->getType()); |
Victor Hernandez | 046e78c | 2009-10-26 23:43:48 +0000 | [diff] [blame] | 116 | } else if (isFreeCall(Inst)) { |
| 117 | Pointer = Inst->getOperand(1); |
| 118 | // calls to free() erase the entire structure |
Chris Lattner | 6290f5c | 2008-12-07 08:50:20 +0000 | [diff] [blame] | 119 | PointerSize = ~0ULL; |
Chris Lattner | 00314b3 | 2008-11-29 09:15:21 +0000 | [diff] [blame] | 120 | } else if (isa<CallInst>(Inst) || isa<InvokeInst>(Inst)) { |
Owen Anderson | f6cec85 | 2009-03-09 05:12:38 +0000 | [diff] [blame] | 121 | // Debug intrinsics don't cause dependences. |
Dale Johannesen | 497cb6f | 2009-03-11 21:13:01 +0000 | [diff] [blame] | 122 | if (isa<DbgInfoIntrinsic>(Inst)) continue; |
Chris Lattner | b51deb9 | 2008-12-05 21:04:20 +0000 | [diff] [blame] | 123 | CallSite InstCS = CallSite::get(Inst); |
| 124 | // If these two calls do not interfere, look past it. |
Chris Lattner | 20d6f09 | 2008-12-09 21:19:42 +0000 | [diff] [blame] | 125 | switch (AA->getModRefInfo(CS, InstCS)) { |
| 126 | case AliasAnalysis::NoModRef: |
| 127 | // If the two calls don't interact (e.g. InstCS is readnone) keep |
| 128 | // scanning. |
Chris Lattner | 00314b3 | 2008-11-29 09:15:21 +0000 | [diff] [blame] | 129 | continue; |
Chris Lattner | 20d6f09 | 2008-12-09 21:19:42 +0000 | [diff] [blame] | 130 | case AliasAnalysis::Ref: |
| 131 | // If the two calls read the same memory locations and CS is a readonly |
| 132 | // function, then we have two cases: 1) the calls may not interfere with |
| 133 | // each other at all. 2) the calls may produce the same value. In case |
| 134 | // #1 we want to ignore the values, in case #2, we want to return Inst |
| 135 | // as a Def dependence. This allows us to CSE in cases like: |
| 136 | // X = strlen(P); |
| 137 | // memchr(...); |
| 138 | // Y = strlen(P); // Y = X |
| 139 | if (isReadOnlyCall) { |
| 140 | if (CS.getCalledFunction() != 0 && |
| 141 | CS.getCalledFunction() == InstCS.getCalledFunction()) |
| 142 | return MemDepResult::getDef(Inst); |
| 143 | // Ignore unrelated read/read call dependences. |
| 144 | continue; |
| 145 | } |
| 146 | // FALL THROUGH |
| 147 | default: |
Chris Lattner | b51deb9 | 2008-12-05 21:04:20 +0000 | [diff] [blame] | 148 | return MemDepResult::getClobber(Inst); |
Chris Lattner | 20d6f09 | 2008-12-09 21:19:42 +0000 | [diff] [blame] | 149 | } |
Chris Lattner | cfbb634 | 2008-11-30 01:44:00 +0000 | [diff] [blame] | 150 | } else { |
| 151 | // Non-memory instruction. |
Owen Anderson | 202da14 | 2007-07-10 20:39:07 +0000 | [diff] [blame] | 152 | continue; |
Chris Lattner | cfbb634 | 2008-11-30 01:44:00 +0000 | [diff] [blame] | 153 | } |
Owen Anderson | 5f32320 | 2007-07-10 17:59:22 +0000 | [diff] [blame] | 154 | |
Chris Lattner | b51deb9 | 2008-12-05 21:04:20 +0000 | [diff] [blame] | 155 | if (AA->getModRefInfo(CS, Pointer, PointerSize) != AliasAnalysis::NoModRef) |
| 156 | return MemDepResult::getClobber(Inst); |
Owen Anderson | 5f32320 | 2007-07-10 17:59:22 +0000 | [diff] [blame] | 157 | } |
| 158 | |
Chris Lattner | 7ebcf03 | 2008-12-07 02:15:47 +0000 | [diff] [blame] | 159 | // No dependence found. If this is the entry block of the function, it is a |
| 160 | // clobber, otherwise it is non-local. |
| 161 | if (BB != &BB->getParent()->getEntryBlock()) |
| 162 | return MemDepResult::getNonLocal(); |
| 163 | return MemDepResult::getClobber(ScanIt); |
Owen Anderson | 5f32320 | 2007-07-10 17:59:22 +0000 | [diff] [blame] | 164 | } |
| 165 | |
Chris Lattner | e79be94 | 2008-12-07 01:50:16 +0000 | [diff] [blame] | 166 | /// getPointerDependencyFrom - Return the instruction on which a memory |
| 167 | /// location depends. If isLoad is true, this routine ignore may-aliases with |
| 168 | /// read-only operations. |
Chris Lattner | fd3dcbe | 2008-11-30 23:17:19 +0000 | [diff] [blame] | 169 | MemDepResult MemoryDependenceAnalysis:: |
Owen Anderson | 4bc737c | 2009-10-28 06:18:42 +0000 | [diff] [blame] | 170 | getPointerDependencyFrom(Value *MemPtr, uint64_t MemSize, bool isLoad, |
Chris Lattner | e79be94 | 2008-12-07 01:50:16 +0000 | [diff] [blame] | 171 | BasicBlock::iterator ScanIt, BasicBlock *BB) { |
Chris Lattner | 7ebcf03 | 2008-12-07 02:15:47 +0000 | [diff] [blame] | 172 | |
Nick Lewycky | f27f115 | 2009-11-22 02:38:11 +0000 | [diff] [blame] | 173 | Value *invariantTag = 0; |
Owen Anderson | 4bc737c | 2009-10-28 06:18:42 +0000 | [diff] [blame] | 174 | |
Chris Lattner | 6290f5c | 2008-12-07 08:50:20 +0000 | [diff] [blame] | 175 | // Walk backwards through the basic block, looking for dependencies. |
Chris Lattner | 5391a1d | 2008-11-29 03:47:00 +0000 | [diff] [blame] | 176 | while (ScanIt != BB->begin()) { |
| 177 | Instruction *Inst = --ScanIt; |
Chris Lattner | a161ab0 | 2008-11-29 09:09:48 +0000 | [diff] [blame] | 178 | |
Owen Anderson | 4bc737c | 2009-10-28 06:18:42 +0000 | [diff] [blame] | 179 | // If we're in an invariant region, no dependencies can be found before |
| 180 | // we pass an invariant-begin marker. |
| 181 | if (invariantTag == Inst) { |
| 182 | invariantTag = 0; |
| 183 | continue; |
Nick Lewycky | f27f115 | 2009-11-22 02:38:11 +0000 | [diff] [blame] | 184 | } else if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(Inst)) { |
Owen Anderson | b62f792 | 2009-10-28 07:05:35 +0000 | [diff] [blame] | 185 | // If we pass an invariant-end marker, then we've just entered an |
| 186 | // invariant region and can start ignoring dependencies. |
Owen Anderson | 4bc737c | 2009-10-28 06:18:42 +0000 | [diff] [blame] | 187 | if (II->getIntrinsicID() == Intrinsic::invariant_end) { |
| 188 | uint64_t invariantSize = ~0ULL; |
Nick Lewycky | f27f115 | 2009-11-22 02:38:11 +0000 | [diff] [blame] | 189 | if (ConstantInt *CI = dyn_cast<ConstantInt>(II->getOperand(2))) |
Owen Anderson | 4bc737c | 2009-10-28 06:18:42 +0000 | [diff] [blame] | 190 | invariantSize = CI->getZExtValue(); |
| 191 | |
| 192 | AliasAnalysis::AliasResult R = |
| 193 | AA->alias(II->getOperand(3), invariantSize, MemPtr, MemSize); |
| 194 | if (R == AliasAnalysis::MustAlias) { |
| 195 | invariantTag = II->getOperand(1); |
| 196 | continue; |
| 197 | } |
Owen Anderson | b62f792 | 2009-10-28 07:05:35 +0000 | [diff] [blame] | 198 | |
| 199 | // If we reach a lifetime begin or end marker, then the query ends here |
| 200 | // because the value is undefined. |
| 201 | } else if (II->getIntrinsicID() == Intrinsic::lifetime_start || |
| 202 | II->getIntrinsicID() == Intrinsic::lifetime_end) { |
| 203 | uint64_t invariantSize = ~0ULL; |
Nick Lewycky | f27f115 | 2009-11-22 02:38:11 +0000 | [diff] [blame] | 204 | if (ConstantInt *CI = dyn_cast<ConstantInt>(II->getOperand(1))) |
Owen Anderson | b62f792 | 2009-10-28 07:05:35 +0000 | [diff] [blame] | 205 | invariantSize = CI->getZExtValue(); |
| 206 | |
| 207 | AliasAnalysis::AliasResult R = |
| 208 | AA->alias(II->getOperand(2), invariantSize, MemPtr, MemSize); |
| 209 | if (R == AliasAnalysis::MustAlias) |
| 210 | return MemDepResult::getDef(II); |
Owen Anderson | 4bc737c | 2009-10-28 06:18:42 +0000 | [diff] [blame] | 211 | } |
| 212 | } |
| 213 | |
| 214 | // If we're querying on a load and we're in an invariant region, we're done |
| 215 | // at this point. Nothing a load depends on can live in an invariant region. |
| 216 | if (isLoad && invariantTag) continue; |
| 217 | |
Owen Anderson | f6cec85 | 2009-03-09 05:12:38 +0000 | [diff] [blame] | 218 | // Debug intrinsics don't cause dependences. |
| 219 | if (isa<DbgInfoIntrinsic>(Inst)) continue; |
| 220 | |
Chris Lattner | cfbb634 | 2008-11-30 01:44:00 +0000 | [diff] [blame] | 221 | // Values depend on loads if the pointers are must aliased. This means that |
| 222 | // a load depends on another must aliased load from the same value. |
Chris Lattner | b51deb9 | 2008-12-05 21:04:20 +0000 | [diff] [blame] | 223 | if (LoadInst *LI = dyn_cast<LoadInst>(Inst)) { |
Chris Lattner | b51deb9 | 2008-12-05 21:04:20 +0000 | [diff] [blame] | 224 | Value *Pointer = LI->getPointerOperand(); |
Dan Gohman | f581213 | 2009-07-31 20:53:12 +0000 | [diff] [blame] | 225 | uint64_t PointerSize = AA->getTypeStoreSize(LI->getType()); |
Chris Lattner | b51deb9 | 2008-12-05 21:04:20 +0000 | [diff] [blame] | 226 | |
| 227 | // If we found a pointer, check if it could be the same as our pointer. |
Chris Lattner | a161ab0 | 2008-11-29 09:09:48 +0000 | [diff] [blame] | 228 | AliasAnalysis::AliasResult R = |
Chris Lattner | d777d40 | 2008-11-30 19:24:31 +0000 | [diff] [blame] | 229 | AA->alias(Pointer, PointerSize, MemPtr, MemSize); |
Chris Lattner | a161ab0 | 2008-11-29 09:09:48 +0000 | [diff] [blame] | 230 | if (R == AliasAnalysis::NoAlias) |
| 231 | continue; |
| 232 | |
| 233 | // May-alias loads don't depend on each other without a dependence. |
Chris Lattner | e79be94 | 2008-12-07 01:50:16 +0000 | [diff] [blame] | 234 | if (isLoad && R == AliasAnalysis::MayAlias) |
Chris Lattner | a161ab0 | 2008-11-29 09:09:48 +0000 | [diff] [blame] | 235 | continue; |
Chris Lattner | 6290f5c | 2008-12-07 08:50:20 +0000 | [diff] [blame] | 236 | // Stores depend on may and must aliased loads, loads depend on must-alias |
| 237 | // loads. |
Chris Lattner | b51deb9 | 2008-12-05 21:04:20 +0000 | [diff] [blame] | 238 | return MemDepResult::getDef(Inst); |
| 239 | } |
| 240 | |
| 241 | if (StoreInst *SI = dyn_cast<StoreInst>(Inst)) { |
Owen Anderson | a85a664 | 2009-10-28 06:30:52 +0000 | [diff] [blame] | 242 | // There can't be stores to the value we care about inside an |
| 243 | // invariant region. |
| 244 | if (invariantTag) continue; |
| 245 | |
Chris Lattner | ab9cf12 | 2009-05-25 21:28:56 +0000 | [diff] [blame] | 246 | // If alias analysis can tell that this store is guaranteed to not modify |
| 247 | // the query pointer, ignore it. Use getModRefInfo to handle cases where |
| 248 | // the query pointer points to constant memory etc. |
| 249 | if (AA->getModRefInfo(SI, MemPtr, MemSize) == AliasAnalysis::NoModRef) |
| 250 | continue; |
| 251 | |
| 252 | // Ok, this store might clobber the query pointer. Check to see if it is |
| 253 | // a must alias: in this case, we want to return this as a def. |
Chris Lattner | b51deb9 | 2008-12-05 21:04:20 +0000 | [diff] [blame] | 254 | Value *Pointer = SI->getPointerOperand(); |
Dan Gohman | f581213 | 2009-07-31 20:53:12 +0000 | [diff] [blame] | 255 | uint64_t PointerSize = AA->getTypeStoreSize(SI->getOperand(0)->getType()); |
Chris Lattner | ab9cf12 | 2009-05-25 21:28:56 +0000 | [diff] [blame] | 256 | |
Chris Lattner | b51deb9 | 2008-12-05 21:04:20 +0000 | [diff] [blame] | 257 | // If we found a pointer, check if it could be the same as our pointer. |
| 258 | AliasAnalysis::AliasResult R = |
| 259 | AA->alias(Pointer, PointerSize, MemPtr, MemSize); |
| 260 | |
| 261 | if (R == AliasAnalysis::NoAlias) |
| 262 | continue; |
| 263 | if (R == AliasAnalysis::MayAlias) |
| 264 | return MemDepResult::getClobber(Inst); |
| 265 | return MemDepResult::getDef(Inst); |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 266 | } |
Chris Lattner | 237a828 | 2008-11-30 01:39:32 +0000 | [diff] [blame] | 267 | |
| 268 | // If this is an allocation, and if we know that the accessed pointer is to |
Chris Lattner | b51deb9 | 2008-12-05 21:04:20 +0000 | [diff] [blame] | 269 | // the allocation, return Def. This means that there is no dependence and |
Chris Lattner | 237a828 | 2008-11-30 01:39:32 +0000 | [diff] [blame] | 270 | // the access can be optimized based on that. For example, a load could |
| 271 | // turn into undef. |
Victor Hernandez | 5c78736 | 2009-10-13 01:42:53 +0000 | [diff] [blame] | 272 | // Note: Only determine this to be a malloc if Inst is the malloc call, not |
| 273 | // a subsequent bitcast of the malloc call result. There can be stores to |
| 274 | // the malloced memory between the malloc call and its bitcast uses, and we |
| 275 | // need to continue scanning until the malloc call. |
Victor Hernandez | 7b929da | 2009-10-23 21:09:37 +0000 | [diff] [blame] | 276 | if (isa<AllocaInst>(Inst) || extractMallocCall(Inst)) { |
Victor Hernandez | 46e8312 | 2009-09-18 21:34:51 +0000 | [diff] [blame] | 277 | Value *AccessPtr = MemPtr->getUnderlyingObject(); |
| 278 | |
| 279 | if (AccessPtr == Inst || |
| 280 | AA->alias(Inst, 1, AccessPtr, 1) == AliasAnalysis::MustAlias) |
| 281 | return MemDepResult::getDef(Inst); |
| 282 | continue; |
| 283 | } |
| 284 | |
Chris Lattner | b51deb9 | 2008-12-05 21:04:20 +0000 | [diff] [blame] | 285 | // See if this instruction (e.g. a call or vaarg) mod/ref's the pointer. |
Chris Lattner | 3579e44 | 2008-12-09 19:47:40 +0000 | [diff] [blame] | 286 | switch (AA->getModRefInfo(Inst, MemPtr, MemSize)) { |
| 287 | case AliasAnalysis::NoModRef: |
| 288 | // If the call has no effect on the queried pointer, just ignore it. |
Chris Lattner | 25a0814 | 2008-11-29 08:51:16 +0000 | [diff] [blame] | 289 | continue; |
Owen Anderson | a85a664 | 2009-10-28 06:30:52 +0000 | [diff] [blame] | 290 | case AliasAnalysis::Mod: |
| 291 | // If we're in an invariant region, we can ignore calls that ONLY |
| 292 | // modify the pointer. |
| 293 | if (invariantTag) continue; |
| 294 | return MemDepResult::getClobber(Inst); |
Chris Lattner | 3579e44 | 2008-12-09 19:47:40 +0000 | [diff] [blame] | 295 | case AliasAnalysis::Ref: |
| 296 | // If the call is known to never store to the pointer, and if this is a |
| 297 | // load query, we can safely ignore it (scan past it). |
| 298 | if (isLoad) |
| 299 | continue; |
Chris Lattner | 3579e44 | 2008-12-09 19:47:40 +0000 | [diff] [blame] | 300 | default: |
| 301 | // Otherwise, there is a potential dependence. Return a clobber. |
| 302 | return MemDepResult::getClobber(Inst); |
| 303 | } |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 304 | } |
| 305 | |
Chris Lattner | 7ebcf03 | 2008-12-07 02:15:47 +0000 | [diff] [blame] | 306 | // No dependence found. If this is the entry block of the function, it is a |
| 307 | // clobber, otherwise it is non-local. |
| 308 | if (BB != &BB->getParent()->getEntryBlock()) |
| 309 | return MemDepResult::getNonLocal(); |
| 310 | return MemDepResult::getClobber(ScanIt); |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 311 | } |
| 312 | |
Chris Lattner | 5391a1d | 2008-11-29 03:47:00 +0000 | [diff] [blame] | 313 | /// getDependency - Return the instruction on which a memory operation |
| 314 | /// depends. |
| 315 | MemDepResult MemoryDependenceAnalysis::getDependency(Instruction *QueryInst) { |
| 316 | Instruction *ScanPos = QueryInst; |
| 317 | |
| 318 | // Check for a cached result |
Chris Lattner | fd3dcbe | 2008-11-30 23:17:19 +0000 | [diff] [blame] | 319 | MemDepResult &LocalCache = LocalDeps[QueryInst]; |
Chris Lattner | 5391a1d | 2008-11-29 03:47:00 +0000 | [diff] [blame] | 320 | |
Chris Lattner | 0ec48dd | 2008-11-29 22:02:15 +0000 | [diff] [blame] | 321 | // If the cached entry is non-dirty, just return it. Note that this depends |
Chris Lattner | fd3dcbe | 2008-11-30 23:17:19 +0000 | [diff] [blame] | 322 | // on MemDepResult's default constructing to 'dirty'. |
| 323 | if (!LocalCache.isDirty()) |
| 324 | return LocalCache; |
Chris Lattner | 5391a1d | 2008-11-29 03:47:00 +0000 | [diff] [blame] | 325 | |
| 326 | // Otherwise, if we have a dirty entry, we know we can start the scan at that |
| 327 | // instruction, which may save us some work. |
Chris Lattner | fd3dcbe | 2008-11-30 23:17:19 +0000 | [diff] [blame] | 328 | if (Instruction *Inst = LocalCache.getInst()) { |
Chris Lattner | 5391a1d | 2008-11-29 03:47:00 +0000 | [diff] [blame] | 329 | ScanPos = Inst; |
Chris Lattner | 4a69bad | 2008-11-30 02:52:26 +0000 | [diff] [blame] | 330 | |
Chris Lattner | d44745d | 2008-12-07 18:39:13 +0000 | [diff] [blame] | 331 | RemoveFromReverseMap(ReverseLocalDeps, Inst, QueryInst); |
Chris Lattner | 4a69bad | 2008-11-30 02:52:26 +0000 | [diff] [blame] | 332 | } |
Chris Lattner | 5391a1d | 2008-11-29 03:47:00 +0000 | [diff] [blame] | 333 | |
Chris Lattner | e79be94 | 2008-12-07 01:50:16 +0000 | [diff] [blame] | 334 | BasicBlock *QueryParent = QueryInst->getParent(); |
| 335 | |
| 336 | Value *MemPtr = 0; |
| 337 | uint64_t MemSize = 0; |
| 338 | |
Chris Lattner | 5391a1d | 2008-11-29 03:47:00 +0000 | [diff] [blame] | 339 | // Do the scan. |
Chris Lattner | e79be94 | 2008-12-07 01:50:16 +0000 | [diff] [blame] | 340 | if (BasicBlock::iterator(QueryInst) == QueryParent->begin()) { |
Chris Lattner | 7ebcf03 | 2008-12-07 02:15:47 +0000 | [diff] [blame] | 341 | // No dependence found. If this is the entry block of the function, it is a |
| 342 | // clobber, otherwise it is non-local. |
| 343 | if (QueryParent != &QueryParent->getParent()->getEntryBlock()) |
| 344 | LocalCache = MemDepResult::getNonLocal(); |
| 345 | else |
| 346 | LocalCache = MemDepResult::getClobber(QueryInst); |
Chris Lattner | e79be94 | 2008-12-07 01:50:16 +0000 | [diff] [blame] | 347 | } else if (StoreInst *SI = dyn_cast<StoreInst>(QueryInst)) { |
| 348 | // If this is a volatile store, don't mess around with it. Just return the |
| 349 | // previous instruction as a clobber. |
| 350 | if (SI->isVolatile()) |
| 351 | LocalCache = MemDepResult::getClobber(--BasicBlock::iterator(ScanPos)); |
| 352 | else { |
| 353 | MemPtr = SI->getPointerOperand(); |
Dan Gohman | f581213 | 2009-07-31 20:53:12 +0000 | [diff] [blame] | 354 | MemSize = AA->getTypeStoreSize(SI->getOperand(0)->getType()); |
Chris Lattner | e79be94 | 2008-12-07 01:50:16 +0000 | [diff] [blame] | 355 | } |
| 356 | } else if (LoadInst *LI = dyn_cast<LoadInst>(QueryInst)) { |
| 357 | // If this is a volatile load, don't mess around with it. Just return the |
| 358 | // previous instruction as a clobber. |
| 359 | if (LI->isVolatile()) |
| 360 | LocalCache = MemDepResult::getClobber(--BasicBlock::iterator(ScanPos)); |
| 361 | else { |
| 362 | MemPtr = LI->getPointerOperand(); |
Dan Gohman | f581213 | 2009-07-31 20:53:12 +0000 | [diff] [blame] | 363 | MemSize = AA->getTypeStoreSize(LI->getType()); |
Chris Lattner | e79be94 | 2008-12-07 01:50:16 +0000 | [diff] [blame] | 364 | } |
Victor Hernandez | 66284e0 | 2009-10-24 04:23:03 +0000 | [diff] [blame] | 365 | } else if (isFreeCall(QueryInst)) { |
Victor Hernandez | 046e78c | 2009-10-26 23:43:48 +0000 | [diff] [blame] | 366 | MemPtr = QueryInst->getOperand(1); |
Victor Hernandez | 66284e0 | 2009-10-24 04:23:03 +0000 | [diff] [blame] | 367 | // calls to free() erase the entire structure, not just a field. |
| 368 | MemSize = ~0UL; |
Chris Lattner | e79be94 | 2008-12-07 01:50:16 +0000 | [diff] [blame] | 369 | } else if (isa<CallInst>(QueryInst) || isa<InvokeInst>(QueryInst)) { |
Chris Lattner | 20d6f09 | 2008-12-09 21:19:42 +0000 | [diff] [blame] | 370 | CallSite QueryCS = CallSite::get(QueryInst); |
| 371 | bool isReadOnly = AA->onlyReadsMemory(QueryCS); |
| 372 | LocalCache = getCallSiteDependencyFrom(QueryCS, isReadOnly, ScanPos, |
Chris Lattner | e79be94 | 2008-12-07 01:50:16 +0000 | [diff] [blame] | 373 | QueryParent); |
Chris Lattner | e79be94 | 2008-12-07 01:50:16 +0000 | [diff] [blame] | 374 | } else { |
| 375 | // Non-memory instruction. |
| 376 | LocalCache = MemDepResult::getClobber(--BasicBlock::iterator(ScanPos)); |
| 377 | } |
| 378 | |
| 379 | // If we need to do a pointer scan, make it happen. |
| 380 | if (MemPtr) |
| 381 | LocalCache = getPointerDependencyFrom(MemPtr, MemSize, |
| 382 | isa<LoadInst>(QueryInst), |
| 383 | ScanPos, QueryParent); |
Chris Lattner | 5391a1d | 2008-11-29 03:47:00 +0000 | [diff] [blame] | 384 | |
| 385 | // Remember the result! |
Chris Lattner | fd3dcbe | 2008-11-30 23:17:19 +0000 | [diff] [blame] | 386 | if (Instruction *I = LocalCache.getInst()) |
Chris Lattner | 8c46527 | 2008-11-29 09:20:15 +0000 | [diff] [blame] | 387 | ReverseLocalDeps[I].insert(QueryInst); |
Chris Lattner | 5391a1d | 2008-11-29 03:47:00 +0000 | [diff] [blame] | 388 | |
Chris Lattner | fd3dcbe | 2008-11-30 23:17:19 +0000 | [diff] [blame] | 389 | return LocalCache; |
Chris Lattner | 5391a1d | 2008-11-29 03:47:00 +0000 | [diff] [blame] | 390 | } |
| 391 | |
Chris Lattner | 12a7db3 | 2009-01-22 07:04:01 +0000 | [diff] [blame] | 392 | #ifndef NDEBUG |
| 393 | /// AssertSorted - This method is used when -debug is specified to verify that |
| 394 | /// cache arrays are properly kept sorted. |
| 395 | static void AssertSorted(MemoryDependenceAnalysis::NonLocalDepInfo &Cache, |
| 396 | int Count = -1) { |
| 397 | if (Count == -1) Count = Cache.size(); |
| 398 | if (Count == 0) return; |
| 399 | |
| 400 | for (unsigned i = 1; i != unsigned(Count); ++i) |
| 401 | assert(Cache[i-1] <= Cache[i] && "Cache isn't sorted!"); |
| 402 | } |
| 403 | #endif |
| 404 | |
Chris Lattner | 1559b36 | 2008-12-09 19:38:05 +0000 | [diff] [blame] | 405 | /// getNonLocalCallDependency - Perform a full dependency query for the |
| 406 | /// specified call, returning the set of blocks that the value is |
Chris Lattner | 37d041c | 2008-11-30 01:18:27 +0000 | [diff] [blame] | 407 | /// potentially live across. The returned set of results will include a |
| 408 | /// "NonLocal" result for all blocks where the value is live across. |
| 409 | /// |
Chris Lattner | 1559b36 | 2008-12-09 19:38:05 +0000 | [diff] [blame] | 410 | /// This method assumes the instruction returns a "NonLocal" dependency |
Chris Lattner | 37d041c | 2008-11-30 01:18:27 +0000 | [diff] [blame] | 411 | /// within its own block. |
| 412 | /// |
Chris Lattner | 1559b36 | 2008-12-09 19:38:05 +0000 | [diff] [blame] | 413 | /// This returns a reference to an internal data structure that may be |
| 414 | /// invalidated on the next non-local query or when an instruction is |
| 415 | /// removed. Clients must copy this data if they want it around longer than |
| 416 | /// that. |
Chris Lattner | bf145d6 | 2008-12-01 01:15:42 +0000 | [diff] [blame] | 417 | const MemoryDependenceAnalysis::NonLocalDepInfo & |
Chris Lattner | 1559b36 | 2008-12-09 19:38:05 +0000 | [diff] [blame] | 418 | MemoryDependenceAnalysis::getNonLocalCallDependency(CallSite QueryCS) { |
| 419 | assert(getDependency(QueryCS.getInstruction()).isNonLocal() && |
| 420 | "getNonLocalCallDependency should only be used on calls with non-local deps!"); |
| 421 | PerInstNLInfo &CacheP = NonLocalDeps[QueryCS.getInstruction()]; |
Chris Lattner | bf145d6 | 2008-12-01 01:15:42 +0000 | [diff] [blame] | 422 | NonLocalDepInfo &Cache = CacheP.first; |
Chris Lattner | 37d041c | 2008-11-30 01:18:27 +0000 | [diff] [blame] | 423 | |
| 424 | /// DirtyBlocks - This is the set of blocks that need to be recomputed. In |
| 425 | /// the cached case, this can happen due to instructions being deleted etc. In |
| 426 | /// the uncached case, this starts out as the set of predecessors we care |
| 427 | /// about. |
| 428 | SmallVector<BasicBlock*, 32> DirtyBlocks; |
| 429 | |
| 430 | if (!Cache.empty()) { |
Chris Lattner | bf145d6 | 2008-12-01 01:15:42 +0000 | [diff] [blame] | 431 | // Okay, we have a cache entry. If we know it is not dirty, just return it |
| 432 | // with no computation. |
| 433 | if (!CacheP.second) { |
| 434 | NumCacheNonLocal++; |
| 435 | return Cache; |
| 436 | } |
| 437 | |
Chris Lattner | 37d041c | 2008-11-30 01:18:27 +0000 | [diff] [blame] | 438 | // If we already have a partially computed set of results, scan them to |
Chris Lattner | bf145d6 | 2008-12-01 01:15:42 +0000 | [diff] [blame] | 439 | // determine what is dirty, seeding our initial DirtyBlocks worklist. |
| 440 | for (NonLocalDepInfo::iterator I = Cache.begin(), E = Cache.end(); |
| 441 | I != E; ++I) |
| 442 | if (I->second.isDirty()) |
| 443 | DirtyBlocks.push_back(I->first); |
Chris Lattner | 37d041c | 2008-11-30 01:18:27 +0000 | [diff] [blame] | 444 | |
Chris Lattner | bf145d6 | 2008-12-01 01:15:42 +0000 | [diff] [blame] | 445 | // Sort the cache so that we can do fast binary search lookups below. |
| 446 | std::sort(Cache.begin(), Cache.end()); |
Chris Lattner | 37d041c | 2008-11-30 01:18:27 +0000 | [diff] [blame] | 447 | |
Chris Lattner | bf145d6 | 2008-12-01 01:15:42 +0000 | [diff] [blame] | 448 | ++NumCacheDirtyNonLocal; |
Chris Lattner | 37d041c | 2008-11-30 01:18:27 +0000 | [diff] [blame] | 449 | //cerr << "CACHED CASE: " << DirtyBlocks.size() << " dirty: " |
| 450 | // << Cache.size() << " cached: " << *QueryInst; |
| 451 | } else { |
| 452 | // Seed DirtyBlocks with each of the preds of QueryInst's block. |
Chris Lattner | 1559b36 | 2008-12-09 19:38:05 +0000 | [diff] [blame] | 453 | BasicBlock *QueryBB = QueryCS.getInstruction()->getParent(); |
Chris Lattner | 511b36c | 2008-12-09 06:44:17 +0000 | [diff] [blame] | 454 | for (BasicBlock **PI = PredCache->GetPreds(QueryBB); *PI; ++PI) |
| 455 | DirtyBlocks.push_back(*PI); |
Chris Lattner | 37d041c | 2008-11-30 01:18:27 +0000 | [diff] [blame] | 456 | NumUncacheNonLocal++; |
| 457 | } |
| 458 | |
Chris Lattner | 20d6f09 | 2008-12-09 21:19:42 +0000 | [diff] [blame] | 459 | // isReadonlyCall - If this is a read-only call, we can be more aggressive. |
| 460 | bool isReadonlyCall = AA->onlyReadsMemory(QueryCS); |
Chris Lattner | 9e59c64 | 2008-12-15 03:35:32 +0000 | [diff] [blame] | 461 | |
Chris Lattner | bf145d6 | 2008-12-01 01:15:42 +0000 | [diff] [blame] | 462 | SmallPtrSet<BasicBlock*, 64> Visited; |
| 463 | |
| 464 | unsigned NumSortedEntries = Cache.size(); |
Chris Lattner | 12a7db3 | 2009-01-22 07:04:01 +0000 | [diff] [blame] | 465 | DEBUG(AssertSorted(Cache)); |
Chris Lattner | bf145d6 | 2008-12-01 01:15:42 +0000 | [diff] [blame] | 466 | |
Chris Lattner | 37d041c | 2008-11-30 01:18:27 +0000 | [diff] [blame] | 467 | // Iterate while we still have blocks to update. |
| 468 | while (!DirtyBlocks.empty()) { |
| 469 | BasicBlock *DirtyBB = DirtyBlocks.back(); |
| 470 | DirtyBlocks.pop_back(); |
| 471 | |
Chris Lattner | bf145d6 | 2008-12-01 01:15:42 +0000 | [diff] [blame] | 472 | // Already processed this block? |
| 473 | if (!Visited.insert(DirtyBB)) |
| 474 | continue; |
Chris Lattner | 37d041c | 2008-11-30 01:18:27 +0000 | [diff] [blame] | 475 | |
Chris Lattner | bf145d6 | 2008-12-01 01:15:42 +0000 | [diff] [blame] | 476 | // Do a binary search to see if we already have an entry for this block in |
| 477 | // the cache set. If so, find it. |
Chris Lattner | 12a7db3 | 2009-01-22 07:04:01 +0000 | [diff] [blame] | 478 | DEBUG(AssertSorted(Cache, NumSortedEntries)); |
Chris Lattner | bf145d6 | 2008-12-01 01:15:42 +0000 | [diff] [blame] | 479 | NonLocalDepInfo::iterator Entry = |
| 480 | std::upper_bound(Cache.begin(), Cache.begin()+NumSortedEntries, |
| 481 | std::make_pair(DirtyBB, MemDepResult())); |
Duncan Sands | 7050f3d | 2008-12-10 09:38:36 +0000 | [diff] [blame] | 482 | if (Entry != Cache.begin() && prior(Entry)->first == DirtyBB) |
Chris Lattner | bf145d6 | 2008-12-01 01:15:42 +0000 | [diff] [blame] | 483 | --Entry; |
| 484 | |
| 485 | MemDepResult *ExistingResult = 0; |
| 486 | if (Entry != Cache.begin()+NumSortedEntries && |
| 487 | Entry->first == DirtyBB) { |
| 488 | // If we already have an entry, and if it isn't already dirty, the block |
| 489 | // is done. |
| 490 | if (!Entry->second.isDirty()) |
| 491 | continue; |
| 492 | |
| 493 | // Otherwise, remember this slot so we can update the value. |
| 494 | ExistingResult = &Entry->second; |
| 495 | } |
| 496 | |
Chris Lattner | 37d041c | 2008-11-30 01:18:27 +0000 | [diff] [blame] | 497 | // If the dirty entry has a pointer, start scanning from it so we don't have |
| 498 | // to rescan the entire block. |
| 499 | BasicBlock::iterator ScanPos = DirtyBB->end(); |
Chris Lattner | bf145d6 | 2008-12-01 01:15:42 +0000 | [diff] [blame] | 500 | if (ExistingResult) { |
| 501 | if (Instruction *Inst = ExistingResult->getInst()) { |
| 502 | ScanPos = Inst; |
Chris Lattner | bf145d6 | 2008-12-01 01:15:42 +0000 | [diff] [blame] | 503 | // We're removing QueryInst's use of Inst. |
Chris Lattner | 1559b36 | 2008-12-09 19:38:05 +0000 | [diff] [blame] | 504 | RemoveFromReverseMap(ReverseNonLocalDeps, Inst, |
| 505 | QueryCS.getInstruction()); |
Chris Lattner | bf145d6 | 2008-12-01 01:15:42 +0000 | [diff] [blame] | 506 | } |
Chris Lattner | f68f310 | 2008-11-30 02:28:25 +0000 | [diff] [blame] | 507 | } |
Chris Lattner | 37d041c | 2008-11-30 01:18:27 +0000 | [diff] [blame] | 508 | |
Chris Lattner | 73ec3cd | 2008-11-30 01:26:32 +0000 | [diff] [blame] | 509 | // Find out if this block has a local dependency for QueryInst. |
Chris Lattner | d8dd934 | 2008-12-07 01:21:14 +0000 | [diff] [blame] | 510 | MemDepResult Dep; |
Chris Lattner | e79be94 | 2008-12-07 01:50:16 +0000 | [diff] [blame] | 511 | |
Chris Lattner | 1559b36 | 2008-12-09 19:38:05 +0000 | [diff] [blame] | 512 | if (ScanPos != DirtyBB->begin()) { |
Chris Lattner | 20d6f09 | 2008-12-09 21:19:42 +0000 | [diff] [blame] | 513 | Dep = getCallSiteDependencyFrom(QueryCS, isReadonlyCall,ScanPos, DirtyBB); |
Chris Lattner | 1559b36 | 2008-12-09 19:38:05 +0000 | [diff] [blame] | 514 | } else if (DirtyBB != &DirtyBB->getParent()->getEntryBlock()) { |
| 515 | // No dependence found. If this is the entry block of the function, it is |
| 516 | // a clobber, otherwise it is non-local. |
| 517 | Dep = MemDepResult::getNonLocal(); |
Chris Lattner | e79be94 | 2008-12-07 01:50:16 +0000 | [diff] [blame] | 518 | } else { |
Chris Lattner | 1559b36 | 2008-12-09 19:38:05 +0000 | [diff] [blame] | 519 | Dep = MemDepResult::getClobber(ScanPos); |
Chris Lattner | e79be94 | 2008-12-07 01:50:16 +0000 | [diff] [blame] | 520 | } |
| 521 | |
Chris Lattner | bf145d6 | 2008-12-01 01:15:42 +0000 | [diff] [blame] | 522 | // If we had a dirty entry for the block, update it. Otherwise, just add |
| 523 | // a new entry. |
| 524 | if (ExistingResult) |
| 525 | *ExistingResult = Dep; |
| 526 | else |
| 527 | Cache.push_back(std::make_pair(DirtyBB, Dep)); |
| 528 | |
Chris Lattner | 37d041c | 2008-11-30 01:18:27 +0000 | [diff] [blame] | 529 | // If the block has a dependency (i.e. it isn't completely transparent to |
Chris Lattner | bf145d6 | 2008-12-01 01:15:42 +0000 | [diff] [blame] | 530 | // the value), remember the association! |
| 531 | if (!Dep.isNonLocal()) { |
Chris Lattner | 37d041c | 2008-11-30 01:18:27 +0000 | [diff] [blame] | 532 | // Keep the ReverseNonLocalDeps map up to date so we can efficiently |
| 533 | // update this when we remove instructions. |
Chris Lattner | bf145d6 | 2008-12-01 01:15:42 +0000 | [diff] [blame] | 534 | if (Instruction *Inst = Dep.getInst()) |
Chris Lattner | 1559b36 | 2008-12-09 19:38:05 +0000 | [diff] [blame] | 535 | ReverseNonLocalDeps[Inst].insert(QueryCS.getInstruction()); |
Chris Lattner | bf145d6 | 2008-12-01 01:15:42 +0000 | [diff] [blame] | 536 | } else { |
Chris Lattner | 37d041c | 2008-11-30 01:18:27 +0000 | [diff] [blame] | 537 | |
Chris Lattner | bf145d6 | 2008-12-01 01:15:42 +0000 | [diff] [blame] | 538 | // If the block *is* completely transparent to the load, we need to check |
| 539 | // the predecessors of this block. Add them to our worklist. |
Chris Lattner | 511b36c | 2008-12-09 06:44:17 +0000 | [diff] [blame] | 540 | for (BasicBlock **PI = PredCache->GetPreds(DirtyBB); *PI; ++PI) |
| 541 | DirtyBlocks.push_back(*PI); |
Chris Lattner | bf145d6 | 2008-12-01 01:15:42 +0000 | [diff] [blame] | 542 | } |
Chris Lattner | 37d041c | 2008-11-30 01:18:27 +0000 | [diff] [blame] | 543 | } |
| 544 | |
Chris Lattner | bf145d6 | 2008-12-01 01:15:42 +0000 | [diff] [blame] | 545 | return Cache; |
Chris Lattner | 37d041c | 2008-11-30 01:18:27 +0000 | [diff] [blame] | 546 | } |
| 547 | |
Chris Lattner | 7ebcf03 | 2008-12-07 02:15:47 +0000 | [diff] [blame] | 548 | /// getNonLocalPointerDependency - Perform a full dependency query for an |
| 549 | /// access to the specified (non-volatile) memory location, returning the |
| 550 | /// set of instructions that either define or clobber the value. |
| 551 | /// |
| 552 | /// This method assumes the pointer has a "NonLocal" dependency within its |
| 553 | /// own block. |
| 554 | /// |
| 555 | void MemoryDependenceAnalysis:: |
| 556 | getNonLocalPointerDependency(Value *Pointer, bool isLoad, BasicBlock *FromBB, |
| 557 | SmallVectorImpl<NonLocalDepEntry> &Result) { |
Chris Lattner | 3f7eb5b | 2008-12-07 18:45:15 +0000 | [diff] [blame] | 558 | assert(isa<PointerType>(Pointer->getType()) && |
| 559 | "Can't get pointer deps of a non-pointer!"); |
Chris Lattner | 9a193fd | 2008-12-07 02:56:57 +0000 | [diff] [blame] | 560 | Result.clear(); |
| 561 | |
Chris Lattner | 7ebcf03 | 2008-12-07 02:15:47 +0000 | [diff] [blame] | 562 | // We know that the pointer value is live into FromBB find the def/clobbers |
| 563 | // from presecessors. |
Chris Lattner | 7ebcf03 | 2008-12-07 02:15:47 +0000 | [diff] [blame] | 564 | const Type *EltTy = cast<PointerType>(Pointer->getType())->getElementType(); |
Dan Gohman | f581213 | 2009-07-31 20:53:12 +0000 | [diff] [blame] | 565 | uint64_t PointeeSize = AA->getTypeStoreSize(EltTy); |
Chris Lattner | 7ebcf03 | 2008-12-07 02:15:47 +0000 | [diff] [blame] | 566 | |
Chris Lattner | 9e59c64 | 2008-12-15 03:35:32 +0000 | [diff] [blame] | 567 | // This is the set of blocks we've inspected, and the pointer we consider in |
| 568 | // each block. Because of critical edges, we currently bail out if querying |
| 569 | // a block with multiple different pointers. This can happen during PHI |
| 570 | // translation. |
| 571 | DenseMap<BasicBlock*, Value*> Visited; |
| 572 | if (!getNonLocalPointerDepFromBB(Pointer, PointeeSize, isLoad, FromBB, |
| 573 | Result, Visited, true)) |
| 574 | return; |
Chris Lattner | 3af23f8 | 2008-12-15 04:58:29 +0000 | [diff] [blame] | 575 | Result.clear(); |
Chris Lattner | 9e59c64 | 2008-12-15 03:35:32 +0000 | [diff] [blame] | 576 | Result.push_back(std::make_pair(FromBB, |
| 577 | MemDepResult::getClobber(FromBB->begin()))); |
Chris Lattner | 9a193fd | 2008-12-07 02:56:57 +0000 | [diff] [blame] | 578 | } |
| 579 | |
Chris Lattner | 9863c3f | 2008-12-09 07:47:11 +0000 | [diff] [blame] | 580 | /// GetNonLocalInfoForBlock - Compute the memdep value for BB with |
| 581 | /// Pointer/PointeeSize using either cached information in Cache or by doing a |
| 582 | /// lookup (which may use dirty cache info if available). If we do a lookup, |
| 583 | /// add the result to the cache. |
| 584 | MemDepResult MemoryDependenceAnalysis:: |
| 585 | GetNonLocalInfoForBlock(Value *Pointer, uint64_t PointeeSize, |
| 586 | bool isLoad, BasicBlock *BB, |
| 587 | NonLocalDepInfo *Cache, unsigned NumSortedEntries) { |
| 588 | |
| 589 | // Do a binary search to see if we already have an entry for this block in |
| 590 | // the cache set. If so, find it. |
| 591 | NonLocalDepInfo::iterator Entry = |
| 592 | std::upper_bound(Cache->begin(), Cache->begin()+NumSortedEntries, |
| 593 | std::make_pair(BB, MemDepResult())); |
Duncan Sands | 7050f3d | 2008-12-10 09:38:36 +0000 | [diff] [blame] | 594 | if (Entry != Cache->begin() && prior(Entry)->first == BB) |
Chris Lattner | 9863c3f | 2008-12-09 07:47:11 +0000 | [diff] [blame] | 595 | --Entry; |
| 596 | |
| 597 | MemDepResult *ExistingResult = 0; |
| 598 | if (Entry != Cache->begin()+NumSortedEntries && Entry->first == BB) |
| 599 | ExistingResult = &Entry->second; |
| 600 | |
| 601 | // If we have a cached entry, and it is non-dirty, use it as the value for |
| 602 | // this dependency. |
| 603 | if (ExistingResult && !ExistingResult->isDirty()) { |
| 604 | ++NumCacheNonLocalPtr; |
| 605 | return *ExistingResult; |
| 606 | } |
| 607 | |
| 608 | // Otherwise, we have to scan for the value. If we have a dirty cache |
| 609 | // entry, start scanning from its position, otherwise we scan from the end |
| 610 | // of the block. |
| 611 | BasicBlock::iterator ScanPos = BB->end(); |
| 612 | if (ExistingResult && ExistingResult->getInst()) { |
| 613 | assert(ExistingResult->getInst()->getParent() == BB && |
| 614 | "Instruction invalidated?"); |
| 615 | ++NumCacheDirtyNonLocalPtr; |
| 616 | ScanPos = ExistingResult->getInst(); |
| 617 | |
| 618 | // Eliminating the dirty entry from 'Cache', so update the reverse info. |
| 619 | ValueIsLoadPair CacheKey(Pointer, isLoad); |
Chris Lattner | 6a0dcc1 | 2009-03-29 00:24:04 +0000 | [diff] [blame] | 620 | RemoveFromReverseMap(ReverseNonLocalPtrDeps, ScanPos, CacheKey); |
Chris Lattner | 9863c3f | 2008-12-09 07:47:11 +0000 | [diff] [blame] | 621 | } else { |
| 622 | ++NumUncacheNonLocalPtr; |
| 623 | } |
| 624 | |
| 625 | // Scan the block for the dependency. |
| 626 | MemDepResult Dep = getPointerDependencyFrom(Pointer, PointeeSize, isLoad, |
| 627 | ScanPos, BB); |
| 628 | |
| 629 | // If we had a dirty entry for the block, update it. Otherwise, just add |
| 630 | // a new entry. |
| 631 | if (ExistingResult) |
| 632 | *ExistingResult = Dep; |
| 633 | else |
| 634 | Cache->push_back(std::make_pair(BB, Dep)); |
| 635 | |
| 636 | // If the block has a dependency (i.e. it isn't completely transparent to |
| 637 | // the value), remember the reverse association because we just added it |
| 638 | // to Cache! |
| 639 | if (Dep.isNonLocal()) |
| 640 | return Dep; |
| 641 | |
| 642 | // Keep the ReverseNonLocalPtrDeps map up to date so we can efficiently |
| 643 | // update MemDep when we remove instructions. |
| 644 | Instruction *Inst = Dep.getInst(); |
| 645 | assert(Inst && "Didn't depend on anything?"); |
| 646 | ValueIsLoadPair CacheKey(Pointer, isLoad); |
Chris Lattner | 6a0dcc1 | 2009-03-29 00:24:04 +0000 | [diff] [blame] | 647 | ReverseNonLocalPtrDeps[Inst].insert(CacheKey); |
Chris Lattner | 9863c3f | 2008-12-09 07:47:11 +0000 | [diff] [blame] | 648 | return Dep; |
| 649 | } |
| 650 | |
Chris Lattner | a2f55dd | 2009-07-13 17:20:05 +0000 | [diff] [blame] | 651 | /// SortNonLocalDepInfoCache - Sort the a NonLocalDepInfo cache, given a certain |
| 652 | /// number of elements in the array that are already properly ordered. This is |
| 653 | /// optimized for the case when only a few entries are added. |
| 654 | static void |
| 655 | SortNonLocalDepInfoCache(MemoryDependenceAnalysis::NonLocalDepInfo &Cache, |
| 656 | unsigned NumSortedEntries) { |
| 657 | switch (Cache.size() - NumSortedEntries) { |
| 658 | case 0: |
| 659 | // done, no new entries. |
| 660 | break; |
| 661 | case 2: { |
| 662 | // Two new entries, insert the last one into place. |
| 663 | MemoryDependenceAnalysis::NonLocalDepEntry Val = Cache.back(); |
| 664 | Cache.pop_back(); |
| 665 | MemoryDependenceAnalysis::NonLocalDepInfo::iterator Entry = |
| 666 | std::upper_bound(Cache.begin(), Cache.end()-1, Val); |
| 667 | Cache.insert(Entry, Val); |
| 668 | // FALL THROUGH. |
| 669 | } |
| 670 | case 1: |
| 671 | // One new entry, Just insert the new value at the appropriate position. |
| 672 | if (Cache.size() != 1) { |
| 673 | MemoryDependenceAnalysis::NonLocalDepEntry Val = Cache.back(); |
| 674 | Cache.pop_back(); |
| 675 | MemoryDependenceAnalysis::NonLocalDepInfo::iterator Entry = |
| 676 | std::upper_bound(Cache.begin(), Cache.end(), Val); |
| 677 | Cache.insert(Entry, Val); |
| 678 | } |
| 679 | break; |
| 680 | default: |
| 681 | // Added many values, do a full scale sort. |
| 682 | std::sort(Cache.begin(), Cache.end()); |
| 683 | break; |
| 684 | } |
| 685 | } |
| 686 | |
Chris Lattner | dc59311 | 2009-11-26 23:18:49 +0000 | [diff] [blame^] | 687 | /// isPHITranslatable - Return true if the specified computation is derived from |
| 688 | /// a PHI node in the current block and if it is simple enough for us to handle. |
| 689 | static bool isPHITranslatable(Instruction *Inst) { |
| 690 | if (isa<PHINode>(Inst)) |
| 691 | return true; |
| 692 | |
| 693 | // TODO: BITCAST, GEP. |
| 694 | |
| 695 | // ... |
| 696 | |
| 697 | // cerr << "MEMDEP: Could not PHI translate: " << *Pointer; |
| 698 | // if (isa<BitCastInst>(PtrInst) || isa<GetElementPtrInst>(PtrInst)) |
| 699 | // cerr << "OP:\t\t\t\t" << *PtrInst->getOperand(0); |
| 700 | |
| 701 | return false; |
| 702 | } |
| 703 | |
| 704 | /// PHITranslateForPred - Given a computation that satisfied the |
| 705 | /// isPHITranslatable predicate, see if we can translate the computation into |
| 706 | /// the specified predecessor block. If so, return that value. |
| 707 | static Value *PHITranslateForPred(Instruction *Inst, BasicBlock *Pred) { |
| 708 | if (PHINode *PN = dyn_cast<PHINode>(Inst)) |
| 709 | return PN->getIncomingValueForBlock(Pred); |
| 710 | |
| 711 | return 0; |
| 712 | } |
| 713 | |
Chris Lattner | 9863c3f | 2008-12-09 07:47:11 +0000 | [diff] [blame] | 714 | |
Chris Lattner | 9e59c64 | 2008-12-15 03:35:32 +0000 | [diff] [blame] | 715 | /// getNonLocalPointerDepFromBB - Perform a dependency query based on |
| 716 | /// pointer/pointeesize starting at the end of StartBB. Add any clobber/def |
| 717 | /// results to the results vector and keep track of which blocks are visited in |
| 718 | /// 'Visited'. |
| 719 | /// |
| 720 | /// This has special behavior for the first block queries (when SkipFirstBlock |
| 721 | /// is true). In this special case, it ignores the contents of the specified |
| 722 | /// block and starts returning dependence info for its predecessors. |
| 723 | /// |
| 724 | /// This function returns false on success, or true to indicate that it could |
| 725 | /// not compute dependence information for some reason. This should be treated |
| 726 | /// as a clobber dependence on the first instruction in the predecessor block. |
| 727 | bool MemoryDependenceAnalysis:: |
Chris Lattner | 9863c3f | 2008-12-09 07:47:11 +0000 | [diff] [blame] | 728 | getNonLocalPointerDepFromBB(Value *Pointer, uint64_t PointeeSize, |
| 729 | bool isLoad, BasicBlock *StartBB, |
| 730 | SmallVectorImpl<NonLocalDepEntry> &Result, |
Chris Lattner | 9e59c64 | 2008-12-15 03:35:32 +0000 | [diff] [blame] | 731 | DenseMap<BasicBlock*, Value*> &Visited, |
| 732 | bool SkipFirstBlock) { |
Chris Lattner | 6636434 | 2009-09-20 22:44:26 +0000 | [diff] [blame] | 733 | |
Chris Lattner | 6290f5c | 2008-12-07 08:50:20 +0000 | [diff] [blame] | 734 | // Look up the cached info for Pointer. |
| 735 | ValueIsLoadPair CacheKey(Pointer, isLoad); |
Chris Lattner | 11dcd8d | 2008-12-08 07:31:50 +0000 | [diff] [blame] | 736 | |
Chris Lattner | 9e59c64 | 2008-12-15 03:35:32 +0000 | [diff] [blame] | 737 | std::pair<BBSkipFirstBlockPair, NonLocalDepInfo> *CacheInfo = |
| 738 | &NonLocalPointerDeps[CacheKey]; |
| 739 | NonLocalDepInfo *Cache = &CacheInfo->second; |
Chris Lattner | 11dcd8d | 2008-12-08 07:31:50 +0000 | [diff] [blame] | 740 | |
| 741 | // If we have valid cached information for exactly the block we are |
| 742 | // investigating, just return it with no recomputation. |
Chris Lattner | 9e59c64 | 2008-12-15 03:35:32 +0000 | [diff] [blame] | 743 | if (CacheInfo->first == BBSkipFirstBlockPair(StartBB, SkipFirstBlock)) { |
Chris Lattner | f478951 | 2008-12-16 07:10:09 +0000 | [diff] [blame] | 744 | // We have a fully cached result for this query then we can just return the |
| 745 | // cached results and populate the visited set. However, we have to verify |
| 746 | // that we don't already have conflicting results for these blocks. Check |
| 747 | // to ensure that if a block in the results set is in the visited set that |
| 748 | // it was for the same pointer query. |
| 749 | if (!Visited.empty()) { |
| 750 | for (NonLocalDepInfo::iterator I = Cache->begin(), E = Cache->end(); |
| 751 | I != E; ++I) { |
| 752 | DenseMap<BasicBlock*, Value*>::iterator VI = Visited.find(I->first); |
| 753 | if (VI == Visited.end() || VI->second == Pointer) continue; |
| 754 | |
| 755 | // We have a pointer mismatch in a block. Just return clobber, saying |
| 756 | // that something was clobbered in this result. We could also do a |
| 757 | // non-fully cached query, but there is little point in doing this. |
| 758 | return true; |
| 759 | } |
| 760 | } |
| 761 | |
Chris Lattner | 11dcd8d | 2008-12-08 07:31:50 +0000 | [diff] [blame] | 762 | for (NonLocalDepInfo::iterator I = Cache->begin(), E = Cache->end(); |
Chris Lattner | f478951 | 2008-12-16 07:10:09 +0000 | [diff] [blame] | 763 | I != E; ++I) { |
| 764 | Visited.insert(std::make_pair(I->first, Pointer)); |
Chris Lattner | 11dcd8d | 2008-12-08 07:31:50 +0000 | [diff] [blame] | 765 | if (!I->second.isNonLocal()) |
| 766 | Result.push_back(*I); |
Chris Lattner | f478951 | 2008-12-16 07:10:09 +0000 | [diff] [blame] | 767 | } |
Chris Lattner | 11dcd8d | 2008-12-08 07:31:50 +0000 | [diff] [blame] | 768 | ++NumCacheCompleteNonLocalPtr; |
Chris Lattner | 9e59c64 | 2008-12-15 03:35:32 +0000 | [diff] [blame] | 769 | return false; |
Chris Lattner | 11dcd8d | 2008-12-08 07:31:50 +0000 | [diff] [blame] | 770 | } |
| 771 | |
| 772 | // Otherwise, either this is a new block, a block with an invalid cache |
| 773 | // pointer or one that we're about to invalidate by putting more info into it |
| 774 | // than its valid cache info. If empty, the result will be valid cache info, |
| 775 | // otherwise it isn't. |
Chris Lattner | 9e59c64 | 2008-12-15 03:35:32 +0000 | [diff] [blame] | 776 | if (Cache->empty()) |
| 777 | CacheInfo->first = BBSkipFirstBlockPair(StartBB, SkipFirstBlock); |
| 778 | else |
| 779 | CacheInfo->first = BBSkipFirstBlockPair(); |
Chris Lattner | 11dcd8d | 2008-12-08 07:31:50 +0000 | [diff] [blame] | 780 | |
| 781 | SmallVector<BasicBlock*, 32> Worklist; |
| 782 | Worklist.push_back(StartBB); |
Chris Lattner | 6290f5c | 2008-12-07 08:50:20 +0000 | [diff] [blame] | 783 | |
| 784 | // Keep track of the entries that we know are sorted. Previously cached |
| 785 | // entries will all be sorted. The entries we add we only sort on demand (we |
| 786 | // don't insert every element into its sorted position). We know that we |
| 787 | // won't get any reuse from currently inserted values, because we don't |
| 788 | // revisit blocks after we insert info for them. |
| 789 | unsigned NumSortedEntries = Cache->size(); |
Chris Lattner | 12a7db3 | 2009-01-22 07:04:01 +0000 | [diff] [blame] | 790 | DEBUG(AssertSorted(*Cache)); |
Chris Lattner | 6290f5c | 2008-12-07 08:50:20 +0000 | [diff] [blame] | 791 | |
Chris Lattner | 7ebcf03 | 2008-12-07 02:15:47 +0000 | [diff] [blame] | 792 | while (!Worklist.empty()) { |
Chris Lattner | 9a193fd | 2008-12-07 02:56:57 +0000 | [diff] [blame] | 793 | BasicBlock *BB = Worklist.pop_back_val(); |
Chris Lattner | 7ebcf03 | 2008-12-07 02:15:47 +0000 | [diff] [blame] | 794 | |
Chris Lattner | 6563371 | 2008-12-09 07:52:59 +0000 | [diff] [blame] | 795 | // Skip the first block if we have it. |
Chris Lattner | 9e59c64 | 2008-12-15 03:35:32 +0000 | [diff] [blame] | 796 | if (!SkipFirstBlock) { |
Chris Lattner | 6563371 | 2008-12-09 07:52:59 +0000 | [diff] [blame] | 797 | // Analyze the dependency of *Pointer in FromBB. See if we already have |
| 798 | // been here. |
Chris Lattner | 9e59c64 | 2008-12-15 03:35:32 +0000 | [diff] [blame] | 799 | assert(Visited.count(BB) && "Should check 'visited' before adding to WL"); |
Chris Lattner | 6290f5c | 2008-12-07 08:50:20 +0000 | [diff] [blame] | 800 | |
Chris Lattner | 6563371 | 2008-12-09 07:52:59 +0000 | [diff] [blame] | 801 | // Get the dependency info for Pointer in BB. If we have cached |
| 802 | // information, we will use it, otherwise we compute it. |
Chris Lattner | 12a7db3 | 2009-01-22 07:04:01 +0000 | [diff] [blame] | 803 | DEBUG(AssertSorted(*Cache, NumSortedEntries)); |
Chris Lattner | 6563371 | 2008-12-09 07:52:59 +0000 | [diff] [blame] | 804 | MemDepResult Dep = GetNonLocalInfoForBlock(Pointer, PointeeSize, isLoad, |
| 805 | BB, Cache, NumSortedEntries); |
| 806 | |
| 807 | // If we got a Def or Clobber, add this to the list of results. |
| 808 | if (!Dep.isNonLocal()) { |
| 809 | Result.push_back(NonLocalDepEntry(BB, Dep)); |
| 810 | continue; |
| 811 | } |
Chris Lattner | 7ebcf03 | 2008-12-07 02:15:47 +0000 | [diff] [blame] | 812 | } |
| 813 | |
Chris Lattner | 9e59c64 | 2008-12-15 03:35:32 +0000 | [diff] [blame] | 814 | // If 'Pointer' is an instruction defined in this block, then we need to do |
| 815 | // phi translation to change it into a value live in the predecessor block. |
| 816 | // If phi translation fails, then we can't continue dependence analysis. |
| 817 | Instruction *PtrInst = dyn_cast<Instruction>(Pointer); |
| 818 | bool NeedsPHITranslation = PtrInst && PtrInst->getParent() == BB; |
| 819 | |
| 820 | // If no PHI translation is needed, just add all the predecessors of this |
| 821 | // block to scan them as well. |
| 822 | if (!NeedsPHITranslation) { |
| 823 | SkipFirstBlock = false; |
| 824 | for (BasicBlock **PI = PredCache->GetPreds(BB); *PI; ++PI) { |
| 825 | // Verify that we haven't looked at this block yet. |
| 826 | std::pair<DenseMap<BasicBlock*,Value*>::iterator, bool> |
| 827 | InsertRes = Visited.insert(std::make_pair(*PI, Pointer)); |
| 828 | if (InsertRes.second) { |
| 829 | // First time we've looked at *PI. |
| 830 | Worklist.push_back(*PI); |
| 831 | continue; |
| 832 | } |
| 833 | |
| 834 | // If we have seen this block before, but it was with a different |
| 835 | // pointer then we have a phi translation failure and we have to treat |
| 836 | // this as a clobber. |
| 837 | if (InsertRes.first->second != Pointer) |
| 838 | goto PredTranslationFailure; |
| 839 | } |
| 840 | continue; |
| 841 | } |
| 842 | |
| 843 | // If we do need to do phi translation, then there are a bunch of different |
| 844 | // cases, because we have to find a Value* live in the predecessor block. We |
| 845 | // know that PtrInst is defined in this block at least. |
Chris Lattner | 6fbc196 | 2009-07-13 17:14:23 +0000 | [diff] [blame] | 846 | |
| 847 | // We may have added values to the cache list before this PHI translation. |
| 848 | // If so, we haven't done anything to ensure that the cache remains sorted. |
| 849 | // Sort it now (if needed) so that recursive invocations of |
| 850 | // getNonLocalPointerDepFromBB and other routines that could reuse the cache |
| 851 | // value will only see properly sorted cache arrays. |
| 852 | if (Cache && NumSortedEntries != Cache->size()) { |
Chris Lattner | a2f55dd | 2009-07-13 17:20:05 +0000 | [diff] [blame] | 853 | SortNonLocalDepInfoCache(*Cache, NumSortedEntries); |
Chris Lattner | 6fbc196 | 2009-07-13 17:14:23 +0000 | [diff] [blame] | 854 | NumSortedEntries = Cache->size(); |
| 855 | } |
Chris Lattner | 9e59c64 | 2008-12-15 03:35:32 +0000 | [diff] [blame] | 856 | |
Chris Lattner | dc59311 | 2009-11-26 23:18:49 +0000 | [diff] [blame^] | 857 | // If this is a computation derived from a PHI node, use the suitably |
| 858 | // translated incoming values for each pred as the phi translated version. |
| 859 | if (isPHITranslatable(PtrInst)) { |
Chris Lattner | 6fbc196 | 2009-07-13 17:14:23 +0000 | [diff] [blame] | 860 | Cache = 0; |
| 861 | |
Chris Lattner | 12a7db3 | 2009-01-22 07:04:01 +0000 | [diff] [blame] | 862 | for (BasicBlock **PI = PredCache->GetPreds(BB); *PI; ++PI) { |
Chris Lattner | 9e59c64 | 2008-12-15 03:35:32 +0000 | [diff] [blame] | 863 | BasicBlock *Pred = *PI; |
Chris Lattner | dc59311 | 2009-11-26 23:18:49 +0000 | [diff] [blame^] | 864 | Value *PredPtr = PHITranslateForPred(PtrInst, Pred); |
| 865 | |
| 866 | // If PHI translation fails, bail out. |
| 867 | if (PredPtr == 0) |
| 868 | goto PredTranslationFailure; |
Chris Lattner | 9e59c64 | 2008-12-15 03:35:32 +0000 | [diff] [blame] | 869 | |
| 870 | // Check to see if we have already visited this pred block with another |
| 871 | // pointer. If so, we can't do this lookup. This failure can occur |
| 872 | // with PHI translation when a critical edge exists and the PHI node in |
| 873 | // the successor translates to a pointer value different than the |
| 874 | // pointer the block was first analyzed with. |
| 875 | std::pair<DenseMap<BasicBlock*,Value*>::iterator, bool> |
| 876 | InsertRes = Visited.insert(std::make_pair(Pred, PredPtr)); |
| 877 | |
| 878 | if (!InsertRes.second) { |
| 879 | // If the predecessor was visited with PredPtr, then we already did |
| 880 | // the analysis and can ignore it. |
| 881 | if (InsertRes.first->second == PredPtr) |
| 882 | continue; |
| 883 | |
| 884 | // Otherwise, the block was previously analyzed with a different |
| 885 | // pointer. We can't represent the result of this case, so we just |
| 886 | // treat this as a phi translation failure. |
| 887 | goto PredTranslationFailure; |
| 888 | } |
Chris Lattner | 12a7db3 | 2009-01-22 07:04:01 +0000 | [diff] [blame] | 889 | |
Chris Lattner | 12a7db3 | 2009-01-22 07:04:01 +0000 | [diff] [blame] | 890 | // FIXME: it is entirely possible that PHI translating will end up with |
| 891 | // the same value. Consider PHI translating something like: |
| 892 | // X = phi [x, bb1], [y, bb2]. PHI translating for bb1 doesn't *need* |
| 893 | // to recurse here, pedantically speaking. |
Chris Lattner | 9e59c64 | 2008-12-15 03:35:32 +0000 | [diff] [blame] | 894 | |
| 895 | // If we have a problem phi translating, fall through to the code below |
| 896 | // to handle the failure condition. |
| 897 | if (getNonLocalPointerDepFromBB(PredPtr, PointeeSize, isLoad, Pred, |
| 898 | Result, Visited)) |
| 899 | goto PredTranslationFailure; |
| 900 | } |
Chris Lattner | 6fbc196 | 2009-07-13 17:14:23 +0000 | [diff] [blame] | 901 | |
Chris Lattner | 9e59c64 | 2008-12-15 03:35:32 +0000 | [diff] [blame] | 902 | // Refresh the CacheInfo/Cache pointer so that it isn't invalidated. |
| 903 | CacheInfo = &NonLocalPointerDeps[CacheKey]; |
| 904 | Cache = &CacheInfo->second; |
Chris Lattner | 12a7db3 | 2009-01-22 07:04:01 +0000 | [diff] [blame] | 905 | NumSortedEntries = Cache->size(); |
Chris Lattner | b54bfc2 | 2009-01-23 00:27:03 +0000 | [diff] [blame] | 906 | |
Chris Lattner | 9e59c64 | 2008-12-15 03:35:32 +0000 | [diff] [blame] | 907 | // Since we did phi translation, the "Cache" set won't contain all of the |
| 908 | // results for the query. This is ok (we can still use it to accelerate |
| 909 | // specific block queries) but we can't do the fastpath "return all |
| 910 | // results from the set" Clear out the indicator for this. |
| 911 | CacheInfo->first = BBSkipFirstBlockPair(); |
| 912 | SkipFirstBlock = false; |
| 913 | continue; |
| 914 | } |
Chris Lattner | dc59311 | 2009-11-26 23:18:49 +0000 | [diff] [blame^] | 915 | |
Chris Lattner | 9e59c64 | 2008-12-15 03:35:32 +0000 | [diff] [blame] | 916 | PredTranslationFailure: |
| 917 | |
Chris Lattner | 95900f2 | 2009-01-23 07:12:16 +0000 | [diff] [blame] | 918 | if (Cache == 0) { |
| 919 | // Refresh the CacheInfo/Cache pointer if it got invalidated. |
| 920 | CacheInfo = &NonLocalPointerDeps[CacheKey]; |
| 921 | Cache = &CacheInfo->second; |
| 922 | NumSortedEntries = Cache->size(); |
Chris Lattner | 95900f2 | 2009-01-23 07:12:16 +0000 | [diff] [blame] | 923 | } |
Chris Lattner | 6fbc196 | 2009-07-13 17:14:23 +0000 | [diff] [blame] | 924 | |
Chris Lattner | 9e59c64 | 2008-12-15 03:35:32 +0000 | [diff] [blame] | 925 | // Since we did phi translation, the "Cache" set won't contain all of the |
| 926 | // results for the query. This is ok (we can still use it to accelerate |
| 927 | // specific block queries) but we can't do the fastpath "return all |
| 928 | // results from the set" Clear out the indicator for this. |
| 929 | CacheInfo->first = BBSkipFirstBlockPair(); |
| 930 | |
| 931 | // If *nothing* works, mark the pointer as being clobbered by the first |
| 932 | // instruction in this block. |
| 933 | // |
| 934 | // If this is the magic first block, return this as a clobber of the whole |
| 935 | // incoming value. Since we can't phi translate to one of the predecessors, |
| 936 | // we have to bail out. |
| 937 | if (SkipFirstBlock) |
| 938 | return true; |
| 939 | |
| 940 | for (NonLocalDepInfo::reverse_iterator I = Cache->rbegin(); ; ++I) { |
| 941 | assert(I != Cache->rend() && "Didn't find current block??"); |
| 942 | if (I->first != BB) |
| 943 | continue; |
| 944 | |
| 945 | assert(I->second.isNonLocal() && |
| 946 | "Should only be here with transparent block"); |
| 947 | I->second = MemDepResult::getClobber(BB->begin()); |
Chris Lattner | 6a0dcc1 | 2009-03-29 00:24:04 +0000 | [diff] [blame] | 948 | ReverseNonLocalPtrDeps[BB->begin()].insert(CacheKey); |
Chris Lattner | 9e59c64 | 2008-12-15 03:35:32 +0000 | [diff] [blame] | 949 | Result.push_back(*I); |
| 950 | break; |
Chris Lattner | 9a193fd | 2008-12-07 02:56:57 +0000 | [diff] [blame] | 951 | } |
Chris Lattner | 7ebcf03 | 2008-12-07 02:15:47 +0000 | [diff] [blame] | 952 | } |
Chris Lattner | 95900f2 | 2009-01-23 07:12:16 +0000 | [diff] [blame] | 953 | |
Chris Lattner | 9863c3f | 2008-12-09 07:47:11 +0000 | [diff] [blame] | 954 | // Okay, we're done now. If we added new values to the cache, re-sort it. |
Chris Lattner | a2f55dd | 2009-07-13 17:20:05 +0000 | [diff] [blame] | 955 | SortNonLocalDepInfoCache(*Cache, NumSortedEntries); |
Chris Lattner | 12a7db3 | 2009-01-22 07:04:01 +0000 | [diff] [blame] | 956 | DEBUG(AssertSorted(*Cache)); |
Chris Lattner | 9e59c64 | 2008-12-15 03:35:32 +0000 | [diff] [blame] | 957 | return false; |
Chris Lattner | 6290f5c | 2008-12-07 08:50:20 +0000 | [diff] [blame] | 958 | } |
| 959 | |
| 960 | /// RemoveCachedNonLocalPointerDependencies - If P exists in |
| 961 | /// CachedNonLocalPointerInfo, remove it. |
| 962 | void MemoryDependenceAnalysis:: |
| 963 | RemoveCachedNonLocalPointerDependencies(ValueIsLoadPair P) { |
| 964 | CachedNonLocalPointerInfo::iterator It = |
| 965 | NonLocalPointerDeps.find(P); |
| 966 | if (It == NonLocalPointerDeps.end()) return; |
| 967 | |
| 968 | // Remove all of the entries in the BB->val map. This involves removing |
| 969 | // instructions from the reverse map. |
Chris Lattner | 11dcd8d | 2008-12-08 07:31:50 +0000 | [diff] [blame] | 970 | NonLocalDepInfo &PInfo = It->second.second; |
Chris Lattner | 6290f5c | 2008-12-07 08:50:20 +0000 | [diff] [blame] | 971 | |
| 972 | for (unsigned i = 0, e = PInfo.size(); i != e; ++i) { |
| 973 | Instruction *Target = PInfo[i].second.getInst(); |
| 974 | if (Target == 0) continue; // Ignore non-local dep results. |
Chris Lattner | 5a45bf1 | 2008-12-09 22:45:32 +0000 | [diff] [blame] | 975 | assert(Target->getParent() == PInfo[i].first); |
Chris Lattner | 6290f5c | 2008-12-07 08:50:20 +0000 | [diff] [blame] | 976 | |
| 977 | // Eliminating the dirty entry from 'Cache', so update the reverse info. |
Chris Lattner | 6a0dcc1 | 2009-03-29 00:24:04 +0000 | [diff] [blame] | 978 | RemoveFromReverseMap(ReverseNonLocalPtrDeps, Target, P); |
Chris Lattner | 6290f5c | 2008-12-07 08:50:20 +0000 | [diff] [blame] | 979 | } |
| 980 | |
| 981 | // Remove P from NonLocalPointerDeps (which deletes NonLocalDepInfo). |
| 982 | NonLocalPointerDeps.erase(It); |
Chris Lattner | 7ebcf03 | 2008-12-07 02:15:47 +0000 | [diff] [blame] | 983 | } |
| 984 | |
| 985 | |
Chris Lattner | bc99be1 | 2008-12-09 22:06:23 +0000 | [diff] [blame] | 986 | /// invalidateCachedPointerInfo - This method is used to invalidate cached |
| 987 | /// information about the specified pointer, because it may be too |
| 988 | /// conservative in memdep. This is an optional call that can be used when |
| 989 | /// the client detects an equivalence between the pointer and some other |
| 990 | /// value and replaces the other value with ptr. This can make Ptr available |
| 991 | /// in more places that cached info does not necessarily keep. |
| 992 | void MemoryDependenceAnalysis::invalidateCachedPointerInfo(Value *Ptr) { |
| 993 | // If Ptr isn't really a pointer, just ignore it. |
| 994 | if (!isa<PointerType>(Ptr->getType())) return; |
| 995 | // Flush store info for the pointer. |
| 996 | RemoveCachedNonLocalPointerDependencies(ValueIsLoadPair(Ptr, false)); |
| 997 | // Flush load info for the pointer. |
| 998 | RemoveCachedNonLocalPointerDependencies(ValueIsLoadPair(Ptr, true)); |
| 999 | } |
| 1000 | |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 1001 | /// removeInstruction - Remove an instruction from the dependence analysis, |
| 1002 | /// updating the dependence of instructions that previously depended on it. |
Owen Anderson | 642a9e3 | 2007-08-08 22:26:03 +0000 | [diff] [blame] | 1003 | /// This method attempts to keep the cache coherent using the reverse map. |
Chris Lattner | 5f589dc | 2008-11-28 22:04:47 +0000 | [diff] [blame] | 1004 | void MemoryDependenceAnalysis::removeInstruction(Instruction *RemInst) { |
Chris Lattner | 5f589dc | 2008-11-28 22:04:47 +0000 | [diff] [blame] | 1005 | // Walk through the Non-local dependencies, removing this one as the value |
| 1006 | // for any cached queries. |
Chris Lattner | f68f310 | 2008-11-30 02:28:25 +0000 | [diff] [blame] | 1007 | NonLocalDepMapType::iterator NLDI = NonLocalDeps.find(RemInst); |
| 1008 | if (NLDI != NonLocalDeps.end()) { |
Chris Lattner | bf145d6 | 2008-12-01 01:15:42 +0000 | [diff] [blame] | 1009 | NonLocalDepInfo &BlockMap = NLDI->second.first; |
Chris Lattner | 25f4b2b | 2008-11-30 02:30:50 +0000 | [diff] [blame] | 1010 | for (NonLocalDepInfo::iterator DI = BlockMap.begin(), DE = BlockMap.end(); |
| 1011 | DI != DE; ++DI) |
Chris Lattner | fd3dcbe | 2008-11-30 23:17:19 +0000 | [diff] [blame] | 1012 | if (Instruction *Inst = DI->second.getInst()) |
Chris Lattner | d44745d | 2008-12-07 18:39:13 +0000 | [diff] [blame] | 1013 | RemoveFromReverseMap(ReverseNonLocalDeps, Inst, RemInst); |
Chris Lattner | f68f310 | 2008-11-30 02:28:25 +0000 | [diff] [blame] | 1014 | NonLocalDeps.erase(NLDI); |
| 1015 | } |
Owen Anderson | 5fc4aba | 2007-12-08 01:37:09 +0000 | [diff] [blame] | 1016 | |
Chris Lattner | 5f589dc | 2008-11-28 22:04:47 +0000 | [diff] [blame] | 1017 | // 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] | 1018 | // |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame] | 1019 | LocalDepMapType::iterator LocalDepEntry = LocalDeps.find(RemInst); |
| 1020 | if (LocalDepEntry != LocalDeps.end()) { |
Chris Lattner | 125ce36 | 2008-11-30 01:09:30 +0000 | [diff] [blame] | 1021 | // Remove us from DepInst's reverse set now that the local dep info is gone. |
Chris Lattner | d44745d | 2008-12-07 18:39:13 +0000 | [diff] [blame] | 1022 | if (Instruction *Inst = LocalDepEntry->second.getInst()) |
| 1023 | RemoveFromReverseMap(ReverseLocalDeps, Inst, RemInst); |
Chris Lattner | 125ce36 | 2008-11-30 01:09:30 +0000 | [diff] [blame] | 1024 | |
Chris Lattner | baad888 | 2008-11-28 22:28:27 +0000 | [diff] [blame] | 1025 | // Remove this local dependency info. |
Chris Lattner | 39f372e | 2008-11-29 01:43:36 +0000 | [diff] [blame] | 1026 | LocalDeps.erase(LocalDepEntry); |
Chris Lattner | 6290f5c | 2008-12-07 08:50:20 +0000 | [diff] [blame] | 1027 | } |
| 1028 | |
| 1029 | // If we have any cached pointer dependencies on this instruction, remove |
| 1030 | // them. If the instruction has non-pointer type, then it can't be a pointer |
| 1031 | // base. |
| 1032 | |
| 1033 | // Remove it from both the load info and the store info. The instruction |
| 1034 | // can't be in either of these maps if it is non-pointer. |
| 1035 | if (isa<PointerType>(RemInst->getType())) { |
| 1036 | RemoveCachedNonLocalPointerDependencies(ValueIsLoadPair(RemInst, false)); |
| 1037 | RemoveCachedNonLocalPointerDependencies(ValueIsLoadPair(RemInst, true)); |
| 1038 | } |
Chris Lattner | baad888 | 2008-11-28 22:28:27 +0000 | [diff] [blame] | 1039 | |
Chris Lattner | d3d12ec | 2008-11-28 22:51:08 +0000 | [diff] [blame] | 1040 | // Loop over all of the things that depend on the instruction we're removing. |
| 1041 | // |
Chris Lattner | 4f8c18c | 2008-11-29 23:30:39 +0000 | [diff] [blame] | 1042 | SmallVector<std::pair<Instruction*, Instruction*>, 8> ReverseDepsToAdd; |
Chris Lattner | 0655f73 | 2008-12-07 18:42:51 +0000 | [diff] [blame] | 1043 | |
| 1044 | // If we find RemInst as a clobber or Def in any of the maps for other values, |
| 1045 | // we need to replace its entry with a dirty version of the instruction after |
| 1046 | // it. If RemInst is a terminator, we use a null dirty value. |
| 1047 | // |
| 1048 | // Using a dirty version of the instruction after RemInst saves having to scan |
| 1049 | // the entire block to get to this point. |
| 1050 | MemDepResult NewDirtyVal; |
| 1051 | if (!RemInst->isTerminator()) |
| 1052 | NewDirtyVal = MemDepResult::getDirty(++BasicBlock::iterator(RemInst)); |
Chris Lattner | 4f8c18c | 2008-11-29 23:30:39 +0000 | [diff] [blame] | 1053 | |
Chris Lattner | 8c46527 | 2008-11-29 09:20:15 +0000 | [diff] [blame] | 1054 | ReverseDepMapType::iterator ReverseDepIt = ReverseLocalDeps.find(RemInst); |
| 1055 | if (ReverseDepIt != ReverseLocalDeps.end()) { |
Chris Lattner | d3d12ec | 2008-11-28 22:51:08 +0000 | [diff] [blame] | 1056 | SmallPtrSet<Instruction*, 4> &ReverseDeps = ReverseDepIt->second; |
Chris Lattner | 6290f5c | 2008-12-07 08:50:20 +0000 | [diff] [blame] | 1057 | // RemInst can't be the terminator if it has local stuff depending on it. |
Chris Lattner | 125ce36 | 2008-11-30 01:09:30 +0000 | [diff] [blame] | 1058 | assert(!ReverseDeps.empty() && !isa<TerminatorInst>(RemInst) && |
| 1059 | "Nothing can locally depend on a terminator"); |
| 1060 | |
Chris Lattner | d3d12ec | 2008-11-28 22:51:08 +0000 | [diff] [blame] | 1061 | for (SmallPtrSet<Instruction*, 4>::iterator I = ReverseDeps.begin(), |
| 1062 | E = ReverseDeps.end(); I != E; ++I) { |
| 1063 | Instruction *InstDependingOnRemInst = *I; |
Chris Lattner | f68f310 | 2008-11-30 02:28:25 +0000 | [diff] [blame] | 1064 | assert(InstDependingOnRemInst != RemInst && |
| 1065 | "Already removed our local dep info"); |
Chris Lattner | 125ce36 | 2008-11-30 01:09:30 +0000 | [diff] [blame] | 1066 | |
Chris Lattner | 0655f73 | 2008-12-07 18:42:51 +0000 | [diff] [blame] | 1067 | LocalDeps[InstDependingOnRemInst] = NewDirtyVal; |
Chris Lattner | d3d12ec | 2008-11-28 22:51:08 +0000 | [diff] [blame] | 1068 | |
Chris Lattner | 125ce36 | 2008-11-30 01:09:30 +0000 | [diff] [blame] | 1069 | // Make sure to remember that new things depend on NewDepInst. |
Chris Lattner | 0655f73 | 2008-12-07 18:42:51 +0000 | [diff] [blame] | 1070 | assert(NewDirtyVal.getInst() && "There is no way something else can have " |
| 1071 | "a local dep on this if it is a terminator!"); |
| 1072 | ReverseDepsToAdd.push_back(std::make_pair(NewDirtyVal.getInst(), |
Chris Lattner | 125ce36 | 2008-11-30 01:09:30 +0000 | [diff] [blame] | 1073 | InstDependingOnRemInst)); |
Chris Lattner | d3d12ec | 2008-11-28 22:51:08 +0000 | [diff] [blame] | 1074 | } |
Chris Lattner | 4f8c18c | 2008-11-29 23:30:39 +0000 | [diff] [blame] | 1075 | |
| 1076 | ReverseLocalDeps.erase(ReverseDepIt); |
| 1077 | |
| 1078 | // Add new reverse deps after scanning the set, to avoid invalidating the |
| 1079 | // 'ReverseDeps' reference. |
| 1080 | while (!ReverseDepsToAdd.empty()) { |
| 1081 | ReverseLocalDeps[ReverseDepsToAdd.back().first] |
| 1082 | .insert(ReverseDepsToAdd.back().second); |
| 1083 | ReverseDepsToAdd.pop_back(); |
| 1084 | } |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 1085 | } |
Owen Anderson | 4d13de4 | 2007-08-16 21:27:05 +0000 | [diff] [blame] | 1086 | |
Chris Lattner | 8c46527 | 2008-11-29 09:20:15 +0000 | [diff] [blame] | 1087 | ReverseDepIt = ReverseNonLocalDeps.find(RemInst); |
| 1088 | if (ReverseDepIt != ReverseNonLocalDeps.end()) { |
Chris Lattner | 6290f5c | 2008-12-07 08:50:20 +0000 | [diff] [blame] | 1089 | SmallPtrSet<Instruction*, 4> &Set = ReverseDepIt->second; |
| 1090 | for (SmallPtrSet<Instruction*, 4>::iterator I = Set.begin(), E = Set.end(); |
Chris Lattner | f68f310 | 2008-11-30 02:28:25 +0000 | [diff] [blame] | 1091 | I != E; ++I) { |
| 1092 | assert(*I != RemInst && "Already removed NonLocalDep info for RemInst"); |
| 1093 | |
Chris Lattner | 4a69bad | 2008-11-30 02:52:26 +0000 | [diff] [blame] | 1094 | PerInstNLInfo &INLD = NonLocalDeps[*I]; |
Chris Lattner | 4a69bad | 2008-11-30 02:52:26 +0000 | [diff] [blame] | 1095 | // The information is now dirty! |
Chris Lattner | bf145d6 | 2008-12-01 01:15:42 +0000 | [diff] [blame] | 1096 | INLD.second = true; |
Chris Lattner | f68f310 | 2008-11-30 02:28:25 +0000 | [diff] [blame] | 1097 | |
Chris Lattner | bf145d6 | 2008-12-01 01:15:42 +0000 | [diff] [blame] | 1098 | for (NonLocalDepInfo::iterator DI = INLD.first.begin(), |
| 1099 | DE = INLD.first.end(); DI != DE; ++DI) { |
Chris Lattner | fd3dcbe | 2008-11-30 23:17:19 +0000 | [diff] [blame] | 1100 | if (DI->second.getInst() != RemInst) continue; |
Chris Lattner | f68f310 | 2008-11-30 02:28:25 +0000 | [diff] [blame] | 1101 | |
| 1102 | // Convert to a dirty entry for the subsequent instruction. |
Chris Lattner | 0655f73 | 2008-12-07 18:42:51 +0000 | [diff] [blame] | 1103 | DI->second = NewDirtyVal; |
| 1104 | |
| 1105 | if (Instruction *NextI = NewDirtyVal.getInst()) |
Chris Lattner | f68f310 | 2008-11-30 02:28:25 +0000 | [diff] [blame] | 1106 | ReverseDepsToAdd.push_back(std::make_pair(NextI, *I)); |
Chris Lattner | f68f310 | 2008-11-30 02:28:25 +0000 | [diff] [blame] | 1107 | } |
| 1108 | } |
Chris Lattner | 4f8c18c | 2008-11-29 23:30:39 +0000 | [diff] [blame] | 1109 | |
| 1110 | ReverseNonLocalDeps.erase(ReverseDepIt); |
| 1111 | |
Chris Lattner | 0ec48dd | 2008-11-29 22:02:15 +0000 | [diff] [blame] | 1112 | // Add new reverse deps after scanning the set, to avoid invalidating 'Set' |
| 1113 | while (!ReverseDepsToAdd.empty()) { |
| 1114 | ReverseNonLocalDeps[ReverseDepsToAdd.back().first] |
| 1115 | .insert(ReverseDepsToAdd.back().second); |
| 1116 | ReverseDepsToAdd.pop_back(); |
| 1117 | } |
Owen Anderson | 4d13de4 | 2007-08-16 21:27:05 +0000 | [diff] [blame] | 1118 | } |
Owen Anderson | 5fc4aba | 2007-12-08 01:37:09 +0000 | [diff] [blame] | 1119 | |
Chris Lattner | 6290f5c | 2008-12-07 08:50:20 +0000 | [diff] [blame] | 1120 | // If the instruction is in ReverseNonLocalPtrDeps then it appears as a |
| 1121 | // value in the NonLocalPointerDeps info. |
| 1122 | ReverseNonLocalPtrDepTy::iterator ReversePtrDepIt = |
| 1123 | ReverseNonLocalPtrDeps.find(RemInst); |
| 1124 | if (ReversePtrDepIt != ReverseNonLocalPtrDeps.end()) { |
Chris Lattner | 6a0dcc1 | 2009-03-29 00:24:04 +0000 | [diff] [blame] | 1125 | SmallPtrSet<ValueIsLoadPair, 4> &Set = ReversePtrDepIt->second; |
Chris Lattner | 6290f5c | 2008-12-07 08:50:20 +0000 | [diff] [blame] | 1126 | SmallVector<std::pair<Instruction*, ValueIsLoadPair>,8> ReversePtrDepsToAdd; |
| 1127 | |
Chris Lattner | 6a0dcc1 | 2009-03-29 00:24:04 +0000 | [diff] [blame] | 1128 | for (SmallPtrSet<ValueIsLoadPair, 4>::iterator I = Set.begin(), |
| 1129 | E = Set.end(); I != E; ++I) { |
| 1130 | ValueIsLoadPair P = *I; |
Chris Lattner | 6290f5c | 2008-12-07 08:50:20 +0000 | [diff] [blame] | 1131 | assert(P.getPointer() != RemInst && |
| 1132 | "Already removed NonLocalPointerDeps info for RemInst"); |
| 1133 | |
Chris Lattner | 11dcd8d | 2008-12-08 07:31:50 +0000 | [diff] [blame] | 1134 | NonLocalDepInfo &NLPDI = NonLocalPointerDeps[P].second; |
| 1135 | |
| 1136 | // The cache is not valid for any specific block anymore. |
Chris Lattner | 9e59c64 | 2008-12-15 03:35:32 +0000 | [diff] [blame] | 1137 | NonLocalPointerDeps[P].first = BBSkipFirstBlockPair(); |
Chris Lattner | 6290f5c | 2008-12-07 08:50:20 +0000 | [diff] [blame] | 1138 | |
Chris Lattner | 6290f5c | 2008-12-07 08:50:20 +0000 | [diff] [blame] | 1139 | // Update any entries for RemInst to use the instruction after it. |
| 1140 | for (NonLocalDepInfo::iterator DI = NLPDI.begin(), DE = NLPDI.end(); |
| 1141 | DI != DE; ++DI) { |
| 1142 | if (DI->second.getInst() != RemInst) continue; |
| 1143 | |
| 1144 | // Convert to a dirty entry for the subsequent instruction. |
| 1145 | DI->second = NewDirtyVal; |
| 1146 | |
| 1147 | if (Instruction *NewDirtyInst = NewDirtyVal.getInst()) |
| 1148 | ReversePtrDepsToAdd.push_back(std::make_pair(NewDirtyInst, P)); |
| 1149 | } |
Chris Lattner | 95900f2 | 2009-01-23 07:12:16 +0000 | [diff] [blame] | 1150 | |
| 1151 | // Re-sort the NonLocalDepInfo. Changing the dirty entry to its |
| 1152 | // subsequent value may invalidate the sortedness. |
| 1153 | std::sort(NLPDI.begin(), NLPDI.end()); |
Chris Lattner | 6290f5c | 2008-12-07 08:50:20 +0000 | [diff] [blame] | 1154 | } |
| 1155 | |
| 1156 | ReverseNonLocalPtrDeps.erase(ReversePtrDepIt); |
| 1157 | |
| 1158 | while (!ReversePtrDepsToAdd.empty()) { |
| 1159 | ReverseNonLocalPtrDeps[ReversePtrDepsToAdd.back().first] |
Chris Lattner | 6a0dcc1 | 2009-03-29 00:24:04 +0000 | [diff] [blame] | 1160 | .insert(ReversePtrDepsToAdd.back().second); |
Chris Lattner | 6290f5c | 2008-12-07 08:50:20 +0000 | [diff] [blame] | 1161 | ReversePtrDepsToAdd.pop_back(); |
| 1162 | } |
| 1163 | } |
| 1164 | |
| 1165 | |
Chris Lattner | f68f310 | 2008-11-30 02:28:25 +0000 | [diff] [blame] | 1166 | assert(!NonLocalDeps.count(RemInst) && "RemInst got reinserted?"); |
Chris Lattner | d777d40 | 2008-11-30 19:24:31 +0000 | [diff] [blame] | 1167 | AA->deleteValue(RemInst); |
Chris Lattner | 5f589dc | 2008-11-28 22:04:47 +0000 | [diff] [blame] | 1168 | DEBUG(verifyRemoved(RemInst)); |
Owen Anderson | 78e02f7 | 2007-07-06 23:14:35 +0000 | [diff] [blame] | 1169 | } |
Chris Lattner | 729b237 | 2008-11-29 21:25:10 +0000 | [diff] [blame] | 1170 | /// verifyRemoved - Verify that the specified instruction does not occur |
| 1171 | /// in our internal data structures. |
| 1172 | void MemoryDependenceAnalysis::verifyRemoved(Instruction *D) const { |
| 1173 | for (LocalDepMapType::const_iterator I = LocalDeps.begin(), |
| 1174 | E = LocalDeps.end(); I != E; ++I) { |
| 1175 | assert(I->first != D && "Inst occurs in data structures"); |
Chris Lattner | fd3dcbe | 2008-11-30 23:17:19 +0000 | [diff] [blame] | 1176 | assert(I->second.getInst() != D && |
Chris Lattner | 729b237 | 2008-11-29 21:25:10 +0000 | [diff] [blame] | 1177 | "Inst occurs in data structures"); |
| 1178 | } |
| 1179 | |
Chris Lattner | 6290f5c | 2008-12-07 08:50:20 +0000 | [diff] [blame] | 1180 | for (CachedNonLocalPointerInfo::const_iterator I =NonLocalPointerDeps.begin(), |
| 1181 | E = NonLocalPointerDeps.end(); I != E; ++I) { |
| 1182 | assert(I->first.getPointer() != D && "Inst occurs in NLPD map key"); |
Chris Lattner | 11dcd8d | 2008-12-08 07:31:50 +0000 | [diff] [blame] | 1183 | const NonLocalDepInfo &Val = I->second.second; |
Chris Lattner | 6290f5c | 2008-12-07 08:50:20 +0000 | [diff] [blame] | 1184 | for (NonLocalDepInfo::const_iterator II = Val.begin(), E = Val.end(); |
| 1185 | II != E; ++II) |
| 1186 | assert(II->second.getInst() != D && "Inst occurs as NLPD value"); |
| 1187 | } |
| 1188 | |
Chris Lattner | 729b237 | 2008-11-29 21:25:10 +0000 | [diff] [blame] | 1189 | for (NonLocalDepMapType::const_iterator I = NonLocalDeps.begin(), |
| 1190 | E = NonLocalDeps.end(); I != E; ++I) { |
| 1191 | assert(I->first != D && "Inst occurs in data structures"); |
Chris Lattner | 4a69bad | 2008-11-30 02:52:26 +0000 | [diff] [blame] | 1192 | const PerInstNLInfo &INLD = I->second; |
Chris Lattner | bf145d6 | 2008-12-01 01:15:42 +0000 | [diff] [blame] | 1193 | for (NonLocalDepInfo::const_iterator II = INLD.first.begin(), |
| 1194 | EE = INLD.first.end(); II != EE; ++II) |
Chris Lattner | fd3dcbe | 2008-11-30 23:17:19 +0000 | [diff] [blame] | 1195 | assert(II->second.getInst() != D && "Inst occurs in data structures"); |
Chris Lattner | 729b237 | 2008-11-29 21:25:10 +0000 | [diff] [blame] | 1196 | } |
| 1197 | |
| 1198 | for (ReverseDepMapType::const_iterator I = ReverseLocalDeps.begin(), |
Chris Lattner | f68f310 | 2008-11-30 02:28:25 +0000 | [diff] [blame] | 1199 | E = ReverseLocalDeps.end(); I != E; ++I) { |
| 1200 | assert(I->first != D && "Inst occurs in data structures"); |
Chris Lattner | 729b237 | 2008-11-29 21:25:10 +0000 | [diff] [blame] | 1201 | for (SmallPtrSet<Instruction*, 4>::const_iterator II = I->second.begin(), |
| 1202 | EE = I->second.end(); II != EE; ++II) |
| 1203 | assert(*II != D && "Inst occurs in data structures"); |
Chris Lattner | f68f310 | 2008-11-30 02:28:25 +0000 | [diff] [blame] | 1204 | } |
Chris Lattner | 729b237 | 2008-11-29 21:25:10 +0000 | [diff] [blame] | 1205 | |
| 1206 | for (ReverseDepMapType::const_iterator I = ReverseNonLocalDeps.begin(), |
| 1207 | E = ReverseNonLocalDeps.end(); |
Chris Lattner | f68f310 | 2008-11-30 02:28:25 +0000 | [diff] [blame] | 1208 | I != E; ++I) { |
| 1209 | assert(I->first != D && "Inst occurs in data structures"); |
Chris Lattner | 729b237 | 2008-11-29 21:25:10 +0000 | [diff] [blame] | 1210 | for (SmallPtrSet<Instruction*, 4>::const_iterator II = I->second.begin(), |
| 1211 | EE = I->second.end(); II != EE; ++II) |
| 1212 | assert(*II != D && "Inst occurs in data structures"); |
Chris Lattner | f68f310 | 2008-11-30 02:28:25 +0000 | [diff] [blame] | 1213 | } |
Chris Lattner | 6290f5c | 2008-12-07 08:50:20 +0000 | [diff] [blame] | 1214 | |
| 1215 | for (ReverseNonLocalPtrDepTy::const_iterator |
| 1216 | I = ReverseNonLocalPtrDeps.begin(), |
| 1217 | E = ReverseNonLocalPtrDeps.end(); I != E; ++I) { |
| 1218 | assert(I->first != D && "Inst occurs in rev NLPD map"); |
| 1219 | |
Chris Lattner | 6a0dcc1 | 2009-03-29 00:24:04 +0000 | [diff] [blame] | 1220 | for (SmallPtrSet<ValueIsLoadPair, 4>::const_iterator II = I->second.begin(), |
Chris Lattner | 6290f5c | 2008-12-07 08:50:20 +0000 | [diff] [blame] | 1221 | E = I->second.end(); II != E; ++II) |
Chris Lattner | 6a0dcc1 | 2009-03-29 00:24:04 +0000 | [diff] [blame] | 1222 | assert(*II != ValueIsLoadPair(D, false) && |
| 1223 | *II != ValueIsLoadPair(D, true) && |
Chris Lattner | 6290f5c | 2008-12-07 08:50:20 +0000 | [diff] [blame] | 1224 | "Inst occurs in ReverseNonLocalPtrDeps map"); |
| 1225 | } |
| 1226 | |
Chris Lattner | 729b237 | 2008-11-29 21:25:10 +0000 | [diff] [blame] | 1227 | } |