| //===- AliasAnalysisEvaluator.cpp - Alias Analysis Accuracy Evaluator -----===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file was developed by the LLVM research group and is distributed under |
| // the University of Illinois Open Source License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file implements a simple N^2 alias analysis accuracy evaluator. |
| // Basically, for each function in the program, it simply queries to see how the |
| // alias analysis implementation answers alias queries between each pair of |
| // pointers in the function. |
| // |
| // This is inspired and adapted from code by: Naveen Neelakantam, Francesco |
| // Spadini, and Wojciech Stryjewski. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "llvm/Analysis/AliasAnalysis.h" |
| #include "llvm/Pass.h" |
| #include "llvm/Function.h" |
| #include "llvm/Type.h" |
| #include "llvm/Support/InstIterator.h" |
| #include "llvm/Assembly/Writer.h" |
| #include "Support/CommandLine.h" |
| #include <set> |
| |
| namespace llvm { |
| |
| namespace { |
| cl::opt<bool> PrintNo ("print-no-aliases", cl::ReallyHidden); |
| cl::opt<bool> PrintMay ("print-may-aliases", cl::ReallyHidden); |
| cl::opt<bool> PrintMust("print-must-aliases", cl::ReallyHidden); |
| |
| class AAEval : public FunctionPass { |
| unsigned No, May, Must; |
| |
| public: |
| virtual void getAnalysisUsage(AnalysisUsage &AU) const { |
| AU.addRequired<AliasAnalysis>(); |
| AU.setPreservesAll(); |
| } |
| |
| bool doInitialization(Module &M) { No = May = Must = 0; return false; } |
| bool runOnFunction(Function &F); |
| bool doFinalization(Module &M); |
| }; |
| |
| RegisterOpt<AAEval> |
| X("aa-eval", "Exhaustive Alias Analysis Precision Evaluator"); |
| } |
| |
| static inline void PrintResults(const char *Msg, bool P, Value *V1, Value *V2) { |
| if (P) { |
| std::cerr << " " << Msg << ":\t"; |
| WriteAsOperand(std::cerr, V1) << ", "; |
| WriteAsOperand(std::cerr, V2) << "\n"; |
| } |
| } |
| |
| bool AAEval::runOnFunction(Function &F) { |
| AliasAnalysis &AA = getAnalysis<AliasAnalysis>(); |
| |
| std::set<Value *> Pointers; |
| |
| for (Function::aiterator I = F.abegin(), E = F.aend(); I != E; ++I) |
| if (isa<PointerType>(I->getType())) // Add all pointer arguments |
| Pointers.insert(I); |
| |
| for (inst_iterator I = inst_begin(F), E = inst_end(F); I != E; ++I) { |
| if (isa<PointerType>((*I)->getType())) // Add all pointer instructions |
| Pointers.insert(*I); |
| for (User::op_iterator OI = (*I)->op_begin(); OI != (*I)->op_end(); ++OI) |
| if (isa<PointerType>((*OI)->getType())) |
| Pointers.insert(*OI); |
| } |
| |
| if (PrintNo || PrintMay || PrintMust) |
| std::cerr << "Function: " << F.getName() << "\n"; |
| |
| // iterate over the worklist, and run the full (n^2)/2 disambiguations |
| for (std::set<Value *>::iterator I1 = Pointers.begin(), E = Pointers.end(); |
| I1 != E; ++I1) |
| for (std::set<Value *>::iterator I2 = Pointers.begin(); I2 != I1; ++I2) |
| switch (AA.alias(*I1, 0, *I2, 0)) { |
| case AliasAnalysis::NoAlias: |
| PrintResults("No", PrintNo, *I1, *I2); |
| ++No; break; |
| case AliasAnalysis::MayAlias: |
| PrintResults("May", PrintMay, *I1, *I2); |
| ++May; break; |
| case AliasAnalysis::MustAlias: |
| PrintResults("Must", PrintMust, *I1, *I2); |
| ++Must; break; |
| default: |
| std::cerr << "Unknown alias query result!\n"; |
| } |
| |
| return false; |
| } |
| |
| bool AAEval::doFinalization(Module &M) { |
| unsigned Sum = No+May+Must; |
| std::cerr << "===== Alias Analysis Evaluator Report =====\n"; |
| if (Sum == 0) { |
| std::cerr << " Alias Analysis Evaluator Summary: No pointers!\n"; |
| return false; |
| } |
| |
| std::cerr << " " << Sum << " Total Alias Queries Performed\n"; |
| std::cerr << " " << No << " no alias responses (" << No*100/Sum << "%)\n"; |
| std::cerr << " " << May << " may alias responses (" << May*100/Sum << "%)\n"; |
| std::cerr << " " << Must << " must alias responses (" <<Must*100/Sum<<"%)\n"; |
| std::cerr << " Alias Analysis Evaluator Summary: " << No*100/Sum << "%/" |
| << May*100/Sum << "%/" << Must*100/Sum<<"%\n"; |
| return false; |
| } |
| |
| } // End llvm namespace |