AliasAnalysisEvaluator.cpp revision d0fde30ce850b78371fd1386338350591f9ff494
1bdf2d80f459d43f5a6df074431bacf41584f81b7shannon.woods@transgaming.com//===- AliasAnalysisEvaluator.cpp - Alias Analysis Accuracy Evaluator -----===// 29ecb9f9d504e71672a610183c34ae33ab276aef4daniel@transgaming.com// 39ecb9f9d504e71672a610183c34ae33ab276aef4daniel@transgaming.com// The LLVM Compiler Infrastructure 49ecb9f9d504e71672a610183c34ae33ab276aef4daniel@transgaming.com// 59ecb9f9d504e71672a610183c34ae33ab276aef4daniel@transgaming.com// This file was developed by the LLVM research group and is distributed under 69ecb9f9d504e71672a610183c34ae33ab276aef4daniel@transgaming.com// the University of Illinois Open Source License. See LICENSE.TXT for details. 79ecb9f9d504e71672a610183c34ae33ab276aef4daniel@transgaming.com// 89ecb9f9d504e71672a610183c34ae33ab276aef4daniel@transgaming.com//===----------------------------------------------------------------------===// 99ecb9f9d504e71672a610183c34ae33ab276aef4daniel@transgaming.com// 109ecb9f9d504e71672a610183c34ae33ab276aef4daniel@transgaming.com// This file implements a simple N^2 alias analysis accuracy evaluator. 119ecb9f9d504e71672a610183c34ae33ab276aef4daniel@transgaming.com// Basically, for each function in the program, it simply queries to see how the 129ecb9f9d504e71672a610183c34ae33ab276aef4daniel@transgaming.com// alias analysis implementation answers alias queries between each pair of 139ecb9f9d504e71672a610183c34ae33ab276aef4daniel@transgaming.com// pointers in the function. 149ecb9f9d504e71672a610183c34ae33ab276aef4daniel@transgaming.com// 159ecb9f9d504e71672a610183c34ae33ab276aef4daniel@transgaming.com// This is inspired and adapted from code by: Naveen Neelakantam, Francesco 169ecb9f9d504e71672a610183c34ae33ab276aef4daniel@transgaming.com// Spadini, and Wojciech Stryjewski. 179ecb9f9d504e71672a610183c34ae33ab276aef4daniel@transgaming.com// 189ecb9f9d504e71672a610183c34ae33ab276aef4daniel@transgaming.com//===----------------------------------------------------------------------===// 199ecb9f9d504e71672a610183c34ae33ab276aef4daniel@transgaming.com 209ecb9f9d504e71672a610183c34ae33ab276aef4daniel@transgaming.com#include "llvm/Analysis/AliasAnalysis.h" 219ecb9f9d504e71672a610183c34ae33ab276aef4daniel@transgaming.com#include "llvm/Pass.h" 229ecb9f9d504e71672a610183c34ae33ab276aef4daniel@transgaming.com#include "llvm/Function.h" 238d012dfca24b1151bdda0599d26ca79eb7817cf2apatrick@chromium.org#include "llvm/Type.h" 249ecb9f9d504e71672a610183c34ae33ab276aef4daniel@transgaming.com#include "llvm/Support/InstIterator.h" 259ecb9f9d504e71672a610183c34ae33ab276aef4daniel@transgaming.com#include "llvm/Assembly/Writer.h" 269ecb9f9d504e71672a610183c34ae33ab276aef4daniel@transgaming.com#include "Support/CommandLine.h" 279ecb9f9d504e71672a610183c34ae33ab276aef4daniel@transgaming.com#include <set> 289ecb9f9d504e71672a610183c34ae33ab276aef4daniel@transgaming.com 299ecb9f9d504e71672a610183c34ae33ab276aef4daniel@transgaming.comnamespace llvm { 309ecb9f9d504e71672a610183c34ae33ab276aef4daniel@transgaming.com 319ecb9f9d504e71672a610183c34ae33ab276aef4daniel@transgaming.comnamespace { 329ecb9f9d504e71672a610183c34ae33ab276aef4daniel@transgaming.com cl::opt<bool> PrintNo ("print-no-aliases", cl::ReallyHidden); 339ecb9f9d504e71672a610183c34ae33ab276aef4daniel@transgaming.com cl::opt<bool> PrintMay ("print-may-aliases", cl::ReallyHidden); 349ecb9f9d504e71672a610183c34ae33ab276aef4daniel@transgaming.com cl::opt<bool> PrintMust("print-must-aliases", cl::ReallyHidden); 359ecb9f9d504e71672a610183c34ae33ab276aef4daniel@transgaming.com 369ecb9f9d504e71672a610183c34ae33ab276aef4daniel@transgaming.com class AAEval : public FunctionPass { 379ecb9f9d504e71672a610183c34ae33ab276aef4daniel@transgaming.com unsigned No, May, Must; 389ecb9f9d504e71672a610183c34ae33ab276aef4daniel@transgaming.com 399ecb9f9d504e71672a610183c34ae33ab276aef4daniel@transgaming.com public: 409ecb9f9d504e71672a610183c34ae33ab276aef4daniel@transgaming.com virtual void getAnalysisUsage(AnalysisUsage &AU) const { 419ecb9f9d504e71672a610183c34ae33ab276aef4daniel@transgaming.com AU.addRequired<AliasAnalysis>(); 429ecb9f9d504e71672a610183c34ae33ab276aef4daniel@transgaming.com AU.setPreservesAll(); 439ecb9f9d504e71672a610183c34ae33ab276aef4daniel@transgaming.com } 449ecb9f9d504e71672a610183c34ae33ab276aef4daniel@transgaming.com 459ecb9f9d504e71672a610183c34ae33ab276aef4daniel@transgaming.com bool doInitialization(Module &M) { No = May = Must = 0; return false; } 469ecb9f9d504e71672a610183c34ae33ab276aef4daniel@transgaming.com bool runOnFunction(Function &F); 479ecb9f9d504e71672a610183c34ae33ab276aef4daniel@transgaming.com bool doFinalization(Module &M); 489ecb9f9d504e71672a610183c34ae33ab276aef4daniel@transgaming.com }; 49 50 RegisterOpt<AAEval> 51 X("aa-eval", "Exhaustive Alias Analysis Precision Evaluator"); 52} 53 54static inline void PrintResults(const char *Msg, bool P, Value *V1, Value *V2) { 55 if (P) { 56 std::cerr << " " << Msg << ":\t"; 57 WriteAsOperand(std::cerr, V1) << ", "; 58 WriteAsOperand(std::cerr, V2) << "\n"; 59 } 60} 61 62bool AAEval::runOnFunction(Function &F) { 63 AliasAnalysis &AA = getAnalysis<AliasAnalysis>(); 64 65 std::set<Value *> Pointers; 66 67 for (Function::aiterator I = F.abegin(), E = F.aend(); I != E; ++I) 68 if (isa<PointerType>(I->getType())) // Add all pointer arguments 69 Pointers.insert(I); 70 71 for (inst_iterator I = inst_begin(F), E = inst_end(F); I != E; ++I) { 72 if (isa<PointerType>((*I)->getType())) // Add all pointer instructions 73 Pointers.insert(*I); 74 for (User::op_iterator OI = (*I)->op_begin(); OI != (*I)->op_end(); ++OI) 75 if (isa<PointerType>((*OI)->getType())) 76 Pointers.insert(*OI); 77 } 78 79 if (PrintNo || PrintMay || PrintMust) 80 std::cerr << "Function: " << F.getName() << "\n"; 81 82 // iterate over the worklist, and run the full (n^2)/2 disambiguations 83 for (std::set<Value *>::iterator I1 = Pointers.begin(), E = Pointers.end(); 84 I1 != E; ++I1) 85 for (std::set<Value *>::iterator I2 = Pointers.begin(); I2 != I1; ++I2) 86 switch (AA.alias(*I1, 0, *I2, 0)) { 87 case AliasAnalysis::NoAlias: 88 PrintResults("No", PrintNo, *I1, *I2); 89 ++No; break; 90 case AliasAnalysis::MayAlias: 91 PrintResults("May", PrintMay, *I1, *I2); 92 ++May; break; 93 case AliasAnalysis::MustAlias: 94 PrintResults("Must", PrintMust, *I1, *I2); 95 ++Must; break; 96 default: 97 std::cerr << "Unknown alias query result!\n"; 98 } 99 100 return false; 101} 102 103bool AAEval::doFinalization(Module &M) { 104 unsigned Sum = No+May+Must; 105 std::cerr << "===== Alias Analysis Evaluator Report =====\n"; 106 if (Sum == 0) { 107 std::cerr << " Alias Analysis Evaluator Summary: No pointers!\n"; 108 return false; 109 } 110 111 std::cerr << " " << Sum << " Total Alias Queries Performed\n"; 112 std::cerr << " " << No << " no alias responses (" << No*100/Sum << "%)\n"; 113 std::cerr << " " << May << " may alias responses (" << May*100/Sum << "%)\n"; 114 std::cerr << " " << Must << " must alias responses (" <<Must*100/Sum<<"%)\n"; 115 std::cerr << " Alias Analysis Evaluator Summary: " << No*100/Sum << "%/" 116 << May*100/Sum << "%/" << Must*100/Sum<<"%\n"; 117 return false; 118} 119 120} // End llvm namespace 121