Line data    Source code

       1             : //===- LiveStacks.h - Live Stack Slot Analysis ------------------*- 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             : // This file implements the live stack slot analysis pass. It is analogous to
      11             : // live interval analysis except it's analyzing liveness of stack slots rather
      12             : // than registers.
      13             : //
      14             : //===----------------------------------------------------------------------===//
      15             : 
      16             : #ifndef LLVM_CODEGEN_LIVESTACKS_H
      17             : #define LLVM_CODEGEN_LIVESTACKS_H
      18             : 
      19             : #include "llvm/CodeGen/LiveInterval.h"
      20             : #include "llvm/CodeGen/MachineFunctionPass.h"
      21             : #include "llvm/Pass.h"
      22             : #include <cassert>
      23             : #include <map>
      24             : #include <unordered_map>
      25             : 
      26             : namespace llvm {
      27             : 
      28             : class TargetRegisterClass;
      29             : class TargetRegisterInfo;
      30             : 
      31             : class LiveStacks : public MachineFunctionPass {
      32             :   const TargetRegisterInfo *TRI;
      33             : 
      34             :   /// Special pool allocator for VNInfo's (LiveInterval val#).
      35             :   ///
      36             :   VNInfo::Allocator VNInfoAllocator;
      37             : 
      38             :   /// S2IMap - Stack slot indices to live interval mapping.
      39             :   using SS2IntervalMap = std::unordered_map<int, LiveInterval>;
      40             :   SS2IntervalMap S2IMap;
      41             : 
      42             :   /// S2RCMap - Stack slot indices to register class mapping.
      43             :   std::map<int, const TargetRegisterClass *> S2RCMap;
      44             : 
      45             : public:
      46             :   static char ID; // Pass identification, replacement for typeid
      47             : 
      48       19760 :   LiveStacks() : MachineFunctionPass(ID) {
      49       19760 :     initializeLiveStacksPass(*PassRegistry::getPassRegistry());
      50       19760 :   }
      51             : 
      52             :   using iterator = SS2IntervalMap::iterator;
      53             :   using const_iterator = SS2IntervalMap::const_iterator;
      54             : 
      55             :   const_iterator begin() const { return S2IMap.begin(); }
      56           0 :   const_iterator end() const { return S2IMap.end(); }
      57             :   iterator begin() { return S2IMap.begin(); }
      58           0 :   iterator end() { return S2IMap.end(); }
      59             : 
      60      194829 :   unsigned getNumIntervals() const { return (unsigned)S2IMap.size(); }
      61             : 
      62             :   LiveInterval &getOrCreateInterval(int Slot, const TargetRegisterClass *RC);
      63             : 
      64             :   LiveInterval &getInterval(int Slot) {
      65             :     assert(Slot >= 0 && "Spill slot indice must be >= 0");
      66             :     SS2IntervalMap::iterator I = S2IMap.find(Slot);
      67             :     assert(I != S2IMap.end() && "Interval does not exist for stack slot");
      68        6861 :     return I->second;
      69             :   }
      70             : 
      71             :   const LiveInterval &getInterval(int Slot) const {
      72             :     assert(Slot >= 0 && "Spill slot indice must be >= 0");
      73             :     SS2IntervalMap::const_iterator I = S2IMap.find(Slot);
      74             :     assert(I != S2IMap.end() && "Interval does not exist for stack slot");
      75             :     return I->second;
      76             :   }
      77             : 
      78             :   bool hasInterval(int Slot) const { return S2IMap.count(Slot); }
      79             : 
      80             :   const TargetRegisterClass *getIntervalRegClass(int Slot) const {
      81             :     assert(Slot >= 0 && "Spill slot indice must be >= 0");
      82             :     std::map<int, const TargetRegisterClass *>::const_iterator I =
      83             :         S2RCMap.find(Slot);
      84             :     assert(I != S2RCMap.end() &&
      85             :            "Register class info does not exist for stack slot");
      86           0 :     return I->second;
      87             :   }
      88             : 
      89       14514 :   VNInfo::Allocator &getVNInfoAllocator() { return VNInfoAllocator; }
      90             : 
      91             :   void getAnalysisUsage(AnalysisUsage &AU) const override;
      92             :   void releaseMemory() override;
      93             : 
      94             :   /// runOnMachineFunction - pass entry point
      95             :   bool runOnMachineFunction(MachineFunction &) override;
      96             : 
      97             :   /// print - Implement the dump method.
      98             :   void print(raw_ostream &O, const Module * = nullptr) const override;
      99             : };
     100             : 
     101             : } // end namespace llvm
     102             : 
     103             : #endif