1 //===- llvm/IR/OptBisect.h - LLVM Bisect support ----------------*- C++ -*-===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 /// 10 /// \file 11 /// This file declares the interface for bisecting optimizations. 12 /// 13 //===----------------------------------------------------------------------===// 14 15 #ifndef LLVM_IR_OPTBISECT_H 16 #define LLVM_IR_OPTBISECT_H 17 18 #include "llvm/ADT/StringRef.h" 19 20 namespace llvm { 21 22 class Pass; 23 24 /// This class implements a mechanism to disable passes and individual 25 /// optimizations at compile time based on a command line option 26 /// (-opt-bisect-limit) in order to perform a bisecting search for 27 /// optimization-related problems. 28 class OptBisect { 29 public: 30 /// \brief Default constructor, initializes the OptBisect state based on the 31 /// -opt-bisect-limit command line argument. 32 /// 33 /// By default, bisection is disabled. 34 /// 35 /// Clients should not instantiate this class directly. All access should go 36 /// through LLVMContext. 37 OptBisect(); 38 39 /// Checks the bisect limit to determine if the specified pass should run. 40 /// 41 /// This function will immediate return true if bisection is disabled. If the 42 /// bisect limit is set to -1, the function will print a message describing 43 /// the pass and the bisect number assigned to it and return true. Otherwise, 44 /// the function will print a message with the bisect number assigned to the 45 /// pass and indicating whether or not the pass will be run and return true if 46 /// the bisect limit has not yet been exceded or false if it has. 47 /// 48 /// Most passes should not call this routine directly. Instead, it is called 49 /// through a helper routine provided by the pass base class. For instance, 50 /// function passes should call FunctionPass::skipFunction(). 51 template <class UnitT> 52 bool shouldRunPass(const Pass *P, const UnitT &U); 53 54 private: 55 bool checkPass(const StringRef PassName, const StringRef TargetDesc); 56 57 bool BisectEnabled = false; 58 unsigned LastBisectNum = 0; 59 }; 60 61 } // end namespace llvm 62 63 #endif // LLVM_IR_OPTBISECT_H 64
