- //===- LiveStacks.h - Live Stack Slot Analysis ------------------*- C++ -*-===// 
- // 
- // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 
- // See https://llvm.org/LICENSE.txt for license information. 
- // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 
- // 
- //===----------------------------------------------------------------------===// 
- // 
- // This file implements the live stack slot analysis pass. It is analogous to 
- // live interval analysis except it's analyzing liveness of stack slots rather 
- // than registers. 
- // 
- //===----------------------------------------------------------------------===// 
-   
- #ifndef LLVM_CODEGEN_LIVESTACKS_H 
- #define LLVM_CODEGEN_LIVESTACKS_H 
-   
- #include "llvm/CodeGen/LiveInterval.h" 
- #include "llvm/CodeGen/MachineFunctionPass.h" 
- #include "llvm/InitializePasses.h" 
- #include "llvm/PassRegistry.h" 
- #include <cassert> 
- #include <map> 
- #include <unordered_map> 
-   
- namespace llvm { 
-   
- class AnalysisUsage; 
- class MachineFunction; 
- class Module; 
- class raw_ostream; 
- class TargetRegisterClass; 
- class TargetRegisterInfo; 
-   
- class LiveStacks : public MachineFunctionPass { 
-   const TargetRegisterInfo *TRI; 
-   
-   /// Special pool allocator for VNInfo's (LiveInterval val#). 
-   /// 
-   VNInfo::Allocator VNInfoAllocator; 
-   
-   /// S2IMap - Stack slot indices to live interval mapping. 
-   using SS2IntervalMap = std::unordered_map<int, LiveInterval>; 
-   SS2IntervalMap S2IMap; 
-   
-   /// S2RCMap - Stack slot indices to register class mapping. 
-   std::map<int, const TargetRegisterClass *> S2RCMap; 
-   
- public: 
-   static char ID; // Pass identification, replacement for typeid 
-   
-   LiveStacks() : MachineFunctionPass(ID) { 
-     initializeLiveStacksPass(*PassRegistry::getPassRegistry()); 
-   } 
-   
-   using iterator = SS2IntervalMap::iterator; 
-   using const_iterator = SS2IntervalMap::const_iterator; 
-   
-   const_iterator begin() const { return S2IMap.begin(); } 
-   const_iterator end() const { return S2IMap.end(); } 
-   iterator begin() { return S2IMap.begin(); } 
-   iterator end() { return S2IMap.end(); } 
-   
-   unsigned getNumIntervals() const { return (unsigned)S2IMap.size(); } 
-   
-   LiveInterval &getOrCreateInterval(int Slot, const TargetRegisterClass *RC); 
-   
-   LiveInterval &getInterval(int Slot) { 
-     assert(Slot >= 0 && "Spill slot indice must be >= 0"); 
-     SS2IntervalMap::iterator I = S2IMap.find(Slot); 
-     assert(I != S2IMap.end() && "Interval does not exist for stack slot"); 
-     return I->second; 
-   } 
-   
-   const LiveInterval &getInterval(int Slot) const { 
-     assert(Slot >= 0 && "Spill slot indice must be >= 0"); 
-     SS2IntervalMap::const_iterator I = S2IMap.find(Slot); 
-     assert(I != S2IMap.end() && "Interval does not exist for stack slot"); 
-     return I->second; 
-   } 
-   
-   bool hasInterval(int Slot) const { return S2IMap.count(Slot); } 
-   
-   const TargetRegisterClass *getIntervalRegClass(int Slot) const { 
-     assert(Slot >= 0 && "Spill slot indice must be >= 0"); 
-     std::map<int, const TargetRegisterClass *>::const_iterator I = 
-         S2RCMap.find(Slot); 
-     assert(I != S2RCMap.end() && 
-            "Register class info does not exist for stack slot"); 
-     return I->second; 
-   } 
-   
-   VNInfo::Allocator &getVNInfoAllocator() { return VNInfoAllocator; } 
-   
-   void getAnalysisUsage(AnalysisUsage &AU) const override; 
-   void releaseMemory() override; 
-   
-   /// runOnMachineFunction - pass entry point 
-   bool runOnMachineFunction(MachineFunction &) override; 
-   
-   /// print - Implement the dump method. 
-   void print(raw_ostream &O, const Module * = nullptr) const override; 
- }; 
-   
- } // end namespace llvm 
-   
- #endif 
-