-//===- llvm/Pass.h - Base class for XForm Passes -----------------*- C++ -*--=//
+//===- llvm/Pass.h - Base class for Passes ----------------------*- C++ -*-===//
//
-// This file defines a base class that indicates that a specified class is a
-// transformation pass implementation.
+// The LLVM Compiler Infrastructure
//
-// Pass's are designed this way so that it is possible to apply N passes to a
-// module, by first doing N Pass specific initializations for the module, then
-// looping over all of the methods in the module, doing method specific work
-// N times for each method. Like this:
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
//
-// for_each(Passes.begin(), Passes.end(), doPassInitialization(Module));
-// for_each(Method *M <- Module->begin(), Module->end())
-// for_each(Passes.begin(), Passes.end(), doPerMethodWork(M));
+//===----------------------------------------------------------------------===//
//
-// The other way to do things is like this:
-// for_each(Pass *P <- Passes.begin(), Passes.end()) {
-// Passes->doPassInitialization(Module)
-// for_each(Module->begin(), Module->end(), P->doPerMethodWork);
-// }
+// This file defines a base class that indicates that a specified class is a
+// transformation pass implementation.
//
-// But this can cause thrashing and poor cache performance, so we don't do it
-// that way.
+// Passes are designed this way so that it is possible to run passes in a cache
+// and organizationally optimal order without having to specify it at the front
+// end. This allows arbitrary passes to be strung together and have them
+// executed as efficiently as possible.
//
-// Because a transformation does not see all methods consecutively, it should
-// be careful about the state that it maintains... another pass may modify a
-// method between two invocatations of doPerMethodWork.
+// Passes should extend one of the classes below, depending on the guarantees
+// that it can make about what will be modified as it is run. For example, most
+// global optimizations should derive from FunctionPass, because they do not add
+// or delete functions, they operate on the internals of the function.
//
-// Also, implementations of doMethodWork should not remove any methods from the
-// module.
+// Note that this file #includes PassSupport.h and PassAnalysisSupport.h (at the
+// bottom), so the APIs exposed by these files are also automatically available
+// to all users of this file.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_PASS_H
#define LLVM_PASS_H
-#include "llvm/Module.h"
-#include "llvm/Method.h"
+#include "llvm/Support/Compiler.h"
+#include <string>
+
+namespace llvm {
+
+class BasicBlock;
+class Function;
+class Module;
+class AnalysisUsage;
+class PassInfo;
+class ImmutablePass;
+class PMStack;
+class AnalysisResolver;
+class PMDataManager;
+class raw_ostream;
+class StringRef;
+
+// AnalysisID - Use the PassInfo to identify a pass...
+typedef const void* AnalysisID;
+
+/// Different types of internal pass managers. External pass managers
+/// (PassManager and FunctionPassManager) are not represented here.
+/// Ordering of pass manager types is important here.
+enum PassManagerType {
+ PMT_Unknown = 0,
+ PMT_ModulePassManager = 1, ///< MPPassManager
+ PMT_CallGraphPassManager, ///< CGPassManager
+ PMT_FunctionPassManager, ///< FPPassManager
+ PMT_LoopPassManager, ///< LPPassManager
+ PMT_RegionPassManager, ///< RGPassManager
+ PMT_BasicBlockPassManager, ///< BBPassManager
+ PMT_Last
+};
+
+// Different types of passes.
+enum PassKind {
+ PT_BasicBlock,
+ PT_Region,
+ PT_Loop,
+ PT_Function,
+ PT_CallGraphSCC,
+ PT_Module,
+ PT_PassManager
+};
//===----------------------------------------------------------------------===//
-// Pass interface - Implemented by all 'passes'.
-//
-struct Pass {
- //===--------------------------------------------------------------------===//
- // The externally useful entry points
- //
-
- // runAllPasses - Run a bunch of passes on the specified module, efficiently.
- static bool runAllPasses(Module *M, std::vector<Pass*> &Passes) {
- bool MadeChanges = false;
- // Run all of the pass initializers
- for (unsigned i = 0; i < Passes.size(); ++i)
- MadeChanges |= Passes[i]->doPassInitialization(M);
-
- // Loop over all of the methods, applying all of the passes to them
- for (unsigned m = 0; m < M->size(); ++m)
- for (unsigned i = 0; i < Passes.size(); ++i)
- MadeChanges |= Passes[i]->doPerMethodWork(*(M->begin()+m));
-
- // Run all of the pass finalizers...
- for (unsigned i = 0; i < Passes.size(); ++i)
- MadeChanges |= Passes[i]->doPassFinalization(M);
- return MadeChanges;
- }
+/// Pass interface - Implemented by all 'passes'. Subclass this if you are an
+/// interprocedural optimization or you do not fit into any of the more
+/// constrained passes described below.
+///
+class Pass {
+ AnalysisResolver *Resolver; // Used to resolve analysis
+ const void *PassID;
+ PassKind Kind;
+ void operator=(const Pass&) = delete;
+ Pass(const Pass &) = delete;
- // runAllPassesAndFree - Run a bunch of passes on the specified module,
- // efficiently. When done, delete all of the passes.
- //
- static bool runAllPassesAndFree(Module *M, std::vector<Pass*> &Passes) {
- // First run all of the passes
- bool MadeChanges = runAllPasses(M, Passes);
-
- // Free all of the passes.
- for (unsigned i = 0; i < Passes.size(); ++i)
- delete Passes[i];
- return MadeChanges;
- }
+public:
+ explicit Pass(PassKind K, char &pid)
+ : Resolver(nullptr), PassID(&pid), Kind(K) { }
+ virtual ~Pass();
- // run(Module*) - Run this pass on a module and all of the methods contained
- // within it. Returns true if any of the contained passes returned true.
- //
- bool run(Module *M) {
- bool MadeChanges = doPassInitialization(M);
+ PassKind getPassKind() const { return Kind; }
- // Loop over methods in the module. doPerMethodWork could add a method to
- // the Module, so we have to keep checking for end of method list condition.
- //
- for (unsigned m = 0; m < M->size(); ++m)
- MadeChanges |= doPerMethodWork(*(M->begin()+m));
- return MadeChanges | doPassFinalization(M);
- }
+ /// getPassName - Return a nice clean name for a pass. This usually
+ /// implemented in terms of the name that is registered by one of the
+ /// Registration templates, but can be overloaded directly.
+ ///
+ virtual const char *getPassName() const;
- // run(Method*) - Run this pass on a module and one specific method. Returns
- // false on success.
- //
- bool run(Method *M) {
- return doPassInitialization(M->getParent()) | doPerMethodWork(M) |
- doPassFinalization(M->getParent());
+ /// getPassID - Return the PassID number that corresponds to this pass.
+ AnalysisID getPassID() const {
+ return PassID;
}
+ /// doInitialization - Virtual method overridden by subclasses to do
+ /// any necessary initialization before any pass is run.
+ ///
+ virtual bool doInitialization(Module &) { return false; }
+
+ /// doFinalization - Virtual method overriden by subclasses to do any
+ /// necessary clean up after all passes have run.
+ ///
+ virtual bool doFinalization(Module &) { return false; }
+
+ /// print - Print out the internal state of the pass. This is called by
+ /// Analyze to print out the contents of an analysis. Otherwise it is not
+ /// necessary to implement this method. Beware that the module pointer MAY be
+ /// null. This automatically forwards to a virtual function that does not
+ /// provide the Module* in case the analysis doesn't need it it can just be
+ /// ignored.
+ ///
+ virtual void print(raw_ostream &O, const Module *M) const;
+ void dump() const; // dump - Print to stderr.
+
+ /// createPrinterPass - Get a Pass appropriate to print the IR this
+ /// pass operates on (Module, Function or MachineFunction).
+ virtual Pass *createPrinterPass(raw_ostream &O,
+ const std::string &Banner) const = 0;
- //===--------------------------------------------------------------------===//
- // Functions to be implemented by subclasses
- //
+ /// Each pass is responsible for assigning a pass manager to itself.
+ /// PMS is the stack of available pass manager.
+ virtual void assignPassManager(PMStack &,
+ PassManagerType) {}
+ /// Check if available pass managers are suitable for this pass or not.
+ virtual void preparePassManager(PMStack &);
- // Destructor - Virtual so we can be subclassed
- inline virtual ~Pass() {}
+ /// Return what kind of Pass Manager can manage this pass.
+ virtual PassManagerType getPotentialPassManagerType() const;
- // doPassInitialization - Virtual method overridden by subclasses to do
- // any neccesary per-module initialization.
- //
- virtual bool doPassInitialization(Module *M) { return false; }
+ // Access AnalysisResolver
+ void setResolver(AnalysisResolver *AR);
+ AnalysisResolver *getResolver() const { return Resolver; }
- // doPerMethodWork - Virtual method overriden by subclasses to do the
- // per-method processing of the pass.
- //
- virtual bool doPerMethodWork(Method *M) { return false; }
+ /// getAnalysisUsage - This function should be overriden by passes that need
+ /// analysis information to do their job. If a pass specifies that it uses a
+ /// particular analysis result to this function, it can then use the
+ /// getAnalysis<AnalysisType>() function, below.
+ ///
+ virtual void getAnalysisUsage(AnalysisUsage &) const;
- // doPassFinalization - Virtual method overriden by subclasses to do any post
- // processing needed after all passes have run.
- //
- virtual bool doPassFinalization(Module *M) { return false; }
+ /// releaseMemory() - This member can be implemented by a pass if it wants to
+ /// be able to release its memory when it is no longer needed. The default
+ /// behavior of passes is to hold onto memory for the entire duration of their
+ /// lifetime (which is the entire compile time). For pipelined passes, this
+ /// is not a big deal because that memory gets recycled every time the pass is
+ /// invoked on another program unit. For IP passes, it is more important to
+ /// free memory when it is unused.
+ ///
+ /// Optionally implement this function to release pass memory when it is no
+ /// longer used.
+ ///
+ virtual void releaseMemory();
+
+ /// getAdjustedAnalysisPointer - This method is used when a pass implements
+ /// an analysis interface through multiple inheritance. If needed, it should
+ /// override this to adjust the this pointer as needed for the specified pass
+ /// info.
+ virtual void *getAdjustedAnalysisPointer(AnalysisID ID);
+ virtual ImmutablePass *getAsImmutablePass();
+ virtual PMDataManager *getAsPMDataManager();
+
+ /// verifyAnalysis() - This member can be implemented by a analysis pass to
+ /// check state of analysis information.
+ virtual void verifyAnalysis() const;
+
+ // dumpPassStructure - Implement the -debug-passes=PassStructure option
+ virtual void dumpPassStructure(unsigned Offset = 0);
+
+ // lookupPassInfo - Return the pass info object for the specified pass class,
+ // or null if it is not known.
+ static const PassInfo *lookupPassInfo(const void *TI);
+
+ // lookupPassInfo - Return the pass info object for the pass with the given
+ // argument string, or null if it is not known.
+ static const PassInfo *lookupPassInfo(StringRef Arg);
+
+ // createPass - Create a object for the specified pass class,
+ // or null if it is not known.
+ static Pass *createPass(AnalysisID ID);
+
+ /// getAnalysisIfAvailable<AnalysisType>() - Subclasses use this function to
+ /// get analysis information that might be around, for example to update it.
+ /// This is different than getAnalysis in that it can fail (if the analysis
+ /// results haven't been computed), so should only be used if you can handle
+ /// the case when the analysis is not available. This method is often used by
+ /// transformation APIs to update analysis results for a pass automatically as
+ /// the transform is performed.
+ ///
+ template<typename AnalysisType> AnalysisType *
+ getAnalysisIfAvailable() const; // Defined in PassAnalysisSupport.h
+
+ /// mustPreserveAnalysisID - This method serves the same function as
+ /// getAnalysisIfAvailable, but works if you just have an AnalysisID. This
+ /// obviously cannot give you a properly typed instance of the class if you
+ /// don't have the class name available (use getAnalysisIfAvailable if you
+ /// do), but it can tell you if you need to preserve the pass at least.
+ ///
+ bool mustPreserveAnalysisID(char &AID) const;
+
+ /// getAnalysis<AnalysisType>() - This function is used by subclasses to get
+ /// to the analysis information that they claim to use by overriding the
+ /// getAnalysisUsage function.
+ ///
+ template<typename AnalysisType>
+ AnalysisType &getAnalysis() const; // Defined in PassAnalysisSupport.h
+
+ template<typename AnalysisType>
+ AnalysisType &getAnalysis(Function &F); // Defined in PassAnalysisSupport.h
+
+ template<typename AnalysisType>
+ AnalysisType &getAnalysisID(AnalysisID PI) const;
+
+ template<typename AnalysisType>
+ AnalysisType &getAnalysisID(AnalysisID PI, Function &F);
};
-#endif
+//===----------------------------------------------------------------------===//
+/// ModulePass class - This class is used to implement unstructured
+/// interprocedural optimizations and analyses. ModulePasses may do anything
+/// they want to the program.
+///
+class ModulePass : public Pass {
+public:
+ /// createPrinterPass - Get a module printer pass.
+ Pass *createPrinterPass(raw_ostream &O,
+ const std::string &Banner) const override;
+
+ /// runOnModule - Virtual method overriden by subclasses to process the module
+ /// being operated on.
+ virtual bool runOnModule(Module &M) = 0;
+
+ void assignPassManager(PMStack &PMS, PassManagerType T) override;
+
+ /// Return what kind of Pass Manager can manage this pass.
+ PassManagerType getPotentialPassManagerType() const override;
+
+ explicit ModulePass(char &pid) : Pass(PT_Module, pid) {}
+ // Force out-of-line virtual method.
+ ~ModulePass() override;
+};
+
+
+//===----------------------------------------------------------------------===//
+/// ImmutablePass class - This class is used to provide information that does
+/// not need to be run. This is useful for things like target information and
+/// "basic" versions of AnalysisGroups.
+///
+class ImmutablePass : public ModulePass {
+public:
+ /// initializePass - This method may be overriden by immutable passes to allow
+ /// them to perform various initialization actions they require. This is
+ /// primarily because an ImmutablePass can "require" another ImmutablePass,
+ /// and if it does, the overloaded version of initializePass may get access to
+ /// these passes with getAnalysis<>.
+ ///
+ virtual void initializePass();
+
+ ImmutablePass *getAsImmutablePass() override { return this; }
+
+ /// ImmutablePasses are never run.
+ ///
+ bool runOnModule(Module &) override { return false; }
+
+ explicit ImmutablePass(char &pid)
+ : ModulePass(pid) {}
+
+ // Force out-of-line virtual method.
+ ~ImmutablePass() override;
+};
+
+//===----------------------------------------------------------------------===//
+/// FunctionPass class - This class is used to implement most global
+/// optimizations. Optimizations should subclass this class if they meet the
+/// following constraints:
+///
+/// 1. Optimizations are organized globally, i.e., a function at a time
+/// 2. Optimizing a function does not cause the addition or removal of any
+/// functions in the module
+///
+class FunctionPass : public Pass {
+public:
+ explicit FunctionPass(char &pid) : Pass(PT_Function, pid) {}
+
+ /// createPrinterPass - Get a function printer pass.
+ Pass *createPrinterPass(raw_ostream &O,
+ const std::string &Banner) const override;
+
+ /// runOnFunction - Virtual method overriden by subclasses to do the
+ /// per-function processing of the pass.
+ ///
+ virtual bool runOnFunction(Function &F) = 0;
+
+ void assignPassManager(PMStack &PMS, PassManagerType T) override;
+
+ /// Return what kind of Pass Manager can manage this pass.
+ PassManagerType getPotentialPassManagerType() const override;
+
+protected:
+ /// skipOptnoneFunction - This function has Attribute::OptimizeNone
+ /// and most transformation passes should skip it.
+ bool skipOptnoneFunction(const Function &F) const;
+};
+
+
+
+//===----------------------------------------------------------------------===//
+/// BasicBlockPass class - This class is used to implement most local
+/// optimizations. Optimizations should subclass this class if they
+/// meet the following constraints:
+/// 1. Optimizations are local, operating on either a basic block or
+/// instruction at a time.
+/// 2. Optimizations do not modify the CFG of the contained function, or any
+/// other basic block in the function.
+/// 3. Optimizations conform to all of the constraints of FunctionPasses.
+///
+class BasicBlockPass : public Pass {
+public:
+ explicit BasicBlockPass(char &pid) : Pass(PT_BasicBlock, pid) {}
+
+ /// createPrinterPass - Get a basic block printer pass.
+ Pass *createPrinterPass(raw_ostream &O,
+ const std::string &Banner) const override;
+
+ using llvm::Pass::doInitialization;
+ using llvm::Pass::doFinalization;
+
+ /// doInitialization - Virtual method overridden by BasicBlockPass subclasses
+ /// to do any necessary per-function initialization.
+ ///
+ virtual bool doInitialization(Function &);
+
+ /// runOnBasicBlock - Virtual method overriden by subclasses to do the
+ /// per-basicblock processing of the pass.
+ ///
+ virtual bool runOnBasicBlock(BasicBlock &BB) = 0;
+
+ /// doFinalization - Virtual method overriden by BasicBlockPass subclasses to
+ /// do any post processing needed after all passes have run.
+ ///
+ virtual bool doFinalization(Function &);
+
+ void assignPassManager(PMStack &PMS, PassManagerType T) override;
+
+ /// Return what kind of Pass Manager can manage this pass.
+ PassManagerType getPotentialPassManagerType() const override;
+
+protected:
+ /// skipOptnoneFunction - Containing function has Attribute::OptimizeNone
+ /// and most transformation passes should skip it.
+ bool skipOptnoneFunction(const BasicBlock &BB) const;
+};
+
+/// If the user specifies the -time-passes argument on an LLVM tool command line
+/// then the value of this boolean will be true, otherwise false.
+/// @brief This is the storage for the -time-passes option.
+extern bool TimePassesIsEnabled;
+
+} // End llvm namespace
+
+// Include support files that contain important APIs commonly used by Passes,
+// but that we want to separate out to make it easier to read the header files.
+//
+#include "llvm/PassSupport.h"
+#include "llvm/PassAnalysisSupport.h"
+
+#endif