Get rid of this for_each loop
[oota-llvm.git] / lib / CodeGen / LiveIntervalAnalysis.h
index 59441fb3bb8312e2a98958b794a8445c67fb23bf..f7f4569cb3518b05f08268bd8311d03642bf8014 100644 (file)
@@ -1,4 +1,4 @@
-//===-- llvm/CodeGen/LiveInterval.h - Live Interval Analysis ----*- C++ -*-===//
+//===-- LiveIntervalAnalysis.h - Live Interval Analysis ---------*- C++ -*-===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 //
 //===----------------------------------------------------------------------===//
 //
-// This file implements the LiveInterval analysis pass.  Given some
-// numbering of each the machine instructions (in this implemention
-// depth-first order) an interval [i, j] is said to be a live interval
-// for register v if there is no instruction with number j' > j such
-// that v is live at j' abd there is no instruction with number i' < i
-// such that v is live at i'. In this implementation intervals can
-// have holes, i.e. an interval might look like [1,20), [50,65),
-// [1000,1001)
+// This file implements the LiveInterval analysis pass.  Given some numbering of
+// each the machine instructions (in this implemention depth-first order) an
+// interval [i, j) is said to be a live interval for register v if there is no
+// instruction with number j' > j such that v is live at j' abd there is no
+// instruction with number i' < i such that v is live at i'. In this
+// implementation intervals can have holes, i.e. an interval might look like
+// [1,20), [50,65), [1000,1001).
 //
 //===----------------------------------------------------------------------===//
 
-#ifndef LLVM_CODEGEN_LIVEINTERVALS_H
-#define LLVM_CODEGEN_LIVEINTERVALS_H
+#ifndef LLVM_CODEGEN_LIVEINTERVAL_ANALYSIS_H
+#define LLVM_CODEGEN_LIVEINTERVAL_ANALYSIS_H
 
+#include "llvm/ADT/DenseMap.h"
 #include "llvm/CodeGen/MachineFunctionPass.h"
-#include <list>
+#include "LiveInterval.h"
 
 namespace llvm {
 
-    class LiveVariables;
-    class MRegisterInfo;
+  class LiveVariables;
+  class MRegisterInfo;
+  class TargetInstrInfo;
+  class VirtRegMap;
 
-    class LiveIntervals : public MachineFunctionPass
-    {
-    public:
-        struct Interval {
-            typedef std::pair<unsigned, unsigned> Range;
-            typedef std::vector<Range> Ranges;
-            unsigned reg;   // the register of this interval
-            float weight;   // weight of this interval (number of uses
-                            // * 10^loopDepth)
-            Ranges ranges;  // the ranges in which this register is live
+  class LiveIntervals : public MachineFunctionPass {
+    MachineFunction* mf_;
+    const TargetMachine* tm_;
+    const MRegisterInfo* mri_;
+    const TargetInstrInfo* tii_;
+    LiveVariables* lv_;
+
+    typedef std::map<MachineInstr*, unsigned> Mi2IndexMap;
+    Mi2IndexMap mi2iMap_;
 
-            Interval(unsigned r);
+    typedef std::vector<MachineInstr*> Index2MiMap;
+    Index2MiMap i2miMap_;
 
-            unsigned start() const {
-                assert(!ranges.empty() && "empty interval for register");
-                return ranges.front().first;
-            }
+    typedef std::map<unsigned, LiveInterval> Reg2IntervalMap;
+    Reg2IntervalMap r2iMap_;
 
-            unsigned end() const {
-                assert(!ranges.empty() && "empty interval for register");
-                return ranges.back().second;
-            }
-
-            bool expiredAt(unsigned index) const {
-                return end() <= (index + 1);
-            }
-
-            bool liveAt(unsigned index) const;
-
-            bool overlaps(const Interval& other) const;
-
-            void addRange(unsigned start, unsigned end);
+    typedef DenseMap<unsigned> Reg2RegMap;
+    Reg2RegMap r2rMap_;
 
-            void join(const Interval& other);
-
-        private:
-            Ranges::iterator mergeRangesForward(Ranges::iterator it);
-
-            Ranges::iterator mergeRangesBackward(Ranges::iterator it);
-        };
-
-        struct StartPointComp {
-            bool operator()(const Interval& lhs, const Interval& rhs) {
-                return lhs.ranges.front().first < rhs.ranges.front().first;
-            }
-        };
-
-        struct EndPointComp {
-            bool operator()(const Interval& lhs, const Interval& rhs) {
-                return lhs.ranges.back().second < rhs.ranges.back().second;
-            }
-        };
-
-        typedef std::list<Interval> Intervals;
-        typedef std::map<unsigned, unsigned> Reg2RegMap;
-        typedef std::vector<MachineBasicBlock*> MachineBasicBlockPtrs;
-
-    private:
-        MachineFunction* mf_;
-        const TargetMachine* tm_;
-        const MRegisterInfo* mri_;
-        MachineBasicBlock* currentMbb_;
-        MachineBasicBlock::iterator currentInstr_;
-        LiveVariables* lv_;
-
-        typedef std::map<unsigned, MachineBasicBlock*> MbbIndex2MbbMap;
-        MbbIndex2MbbMap mbbi2mbbMap_;
-
-        typedef std::map<MachineInstr*, unsigned> Mi2IndexMap;
-        Mi2IndexMap mi2iMap_;
-
-        typedef std::map<unsigned, Intervals::iterator> Reg2IntervalMap;
-        Reg2IntervalMap r2iMap_;
-
-        Reg2RegMap r2rMap_;
-
-        Intervals intervals_;
-
-    public:
-        virtual void getAnalysisUsage(AnalysisUsage &AU) const;
-        virtual void releaseMemory();
-
-        /// runOnMachineFunction - pass entry point
-        virtual bool runOnMachineFunction(MachineFunction&);
-
-        Intervals& getIntervals() { return intervals_; }
-
-        MachineBasicBlockPtrs getOrderedMachineBasicBlockPtrs() const {
-            MachineBasicBlockPtrs result;
-            for (MbbIndex2MbbMap::const_iterator
-                     it = mbbi2mbbMap_.begin(), itEnd = mbbi2mbbMap_.end();
-                 it != itEnd; ++it) {
-                result.push_back(it->second);
-            }
-            return result;
-        }
-
-        const Reg2RegMap& getJoinedRegMap() const {
-            return r2rMap_;
-        }
-
-        /// rep - returns the representative of this register
-        unsigned rep(unsigned reg);
+    std::vector<bool> allocatableRegs_;
 
-    private:
-        /// computeIntervals - compute live intervals
-        void computeIntervals();
+  public:
+    struct InstrSlots
+    {
+      enum {
+        LOAD  = 0,
+        USE   = 1,
+        DEF   = 2,
+        STORE = 3,
+        NUM   = 4,
+      };
+    };
 
-        /// joinIntervals - join compatible live intervals
-        void joinIntervals();
+    static unsigned getBaseIndex(unsigned index) {
+      return index - (index % InstrSlots::NUM);
+    }
+    static unsigned getBoundaryIndex(unsigned index) {
+      return getBaseIndex(index + InstrSlots::NUM - 1);
+    }
+    static unsigned getLoadIndex(unsigned index) {
+      return getBaseIndex(index) + InstrSlots::LOAD;
+    }
+    static unsigned getUseIndex(unsigned index) {
+      return getBaseIndex(index) + InstrSlots::USE;
+    }
+    static unsigned getDefIndex(unsigned index) {
+      return getBaseIndex(index) + InstrSlots::DEF;
+    }
+    static unsigned getStoreIndex(unsigned index) {
+      return getBaseIndex(index) + InstrSlots::STORE;
+    }
 
-        /// handleRegisterDef - update intervals for a register def
-        /// (calls handlePhysicalRegisterDef and
-        /// handleVirtualRegisterDef)
-        void handleRegisterDef(MachineBasicBlock* mbb,
-                               MachineBasicBlock::iterator mi,
-                               unsigned reg);
+    typedef Reg2IntervalMap::iterator iterator;
+    typedef Reg2IntervalMap::const_iterator const_iterator;
+    const_iterator begin() const { return r2iMap_.begin(); }
+    const_iterator end() const { return r2iMap_.end(); }
+    iterator begin() { return r2iMap_.begin(); }
+    iterator end() { return r2iMap_.end(); }
+    unsigned getNumIntervals() const { return r2iMap_.size(); }
+
+    LiveInterval &getInterval(unsigned reg) {
+      Reg2IntervalMap::iterator I = r2iMap_.find(reg);
+      assert(I != r2iMap_.end() && "Interval does not exist for register");
+      return I->second;
+    }
 
-        /// handleVirtualRegisterDef - update intervals for a virtual
-        /// register def
-        void handleVirtualRegisterDef(MachineBasicBlock* mbb,
-                                      MachineBasicBlock::iterator mi,
-                                      unsigned reg);
+    const LiveInterval &getInterval(unsigned reg) const {
+      Reg2IntervalMap::const_iterator I = r2iMap_.find(reg);
+      assert(I != r2iMap_.end() && "Interval does not exist for register");
+      return I->second;
+    }
 
-        /// handlePhysicalRegisterDef - update intervals for a
-        /// physical register def
-        void handlePhysicalRegisterDef(MachineBasicBlock* mbb,
-                                       MachineBasicBlock::iterator mi,
-                                       unsigned reg);
+    /// getInstructionIndex - returns the base index of instr
+    unsigned getInstructionIndex(MachineInstr* instr) const {
+      Mi2IndexMap::const_iterator it = mi2iMap_.find(instr);
+      assert(it != mi2iMap_.end() && "Invalid instruction!");
+      return it->second;
+    }
 
-        bool overlapsAliases(const Interval& lhs, const Interval& rhs) const;
+    /// getInstructionFromIndex - given an index in any slot of an
+    /// instruction return a pointer the instruction
+    MachineInstr* getInstructionFromIndex(unsigned index) const {
+      index /= InstrSlots::NUM; // convert index to vector index
+      assert(index < i2miMap_.size() &&
+             "index does not correspond to an instruction");
+      return i2miMap_[index];
+    }
 
-        unsigned getInstructionIndex(MachineInstr* instr) const {
-            assert(mi2iMap_.count(instr) && "instruction not assigned a number");
-            return mi2iMap_.find(instr)->second;
-        }
-
-        void printRegName(unsigned reg) const;
-    };
+    std::vector<LiveInterval*> addIntervalsForSpills(const LiveInterval& i,
+                                                     VirtRegMap& vrm,
+                                                     int slot);
+
+    virtual void getAnalysisUsage(AnalysisUsage &AU) const;
+    virtual void releaseMemory();
+
+    /// runOnMachineFunction - pass entry point
+    virtual bool runOnMachineFunction(MachineFunction&);
+
+    /// print - Implement the dump method.
+    virtual void print(std::ostream &O, const Module* = 0) const;
+
+  private:
+    /// computeIntervals - compute live intervals
+    void computeIntervals();
+
+    /// joinIntervals - join compatible live intervals
+    void joinIntervals();
+
+    /// joinIntervalsInMachineBB - Join intervals based on move
+    /// instructions in the specified basic block.
+    void joinIntervalsInMachineBB(MachineBasicBlock *MBB);
+
+    /// handleRegisterDef - update intervals for a register def
+    /// (calls handlePhysicalRegisterDef and
+    /// handleVirtualRegisterDef)
+    void handleRegisterDef(MachineBasicBlock* mbb,
+                           MachineBasicBlock::iterator mi,
+                           unsigned reg);
+
+    /// handleVirtualRegisterDef - update intervals for a virtual
+    /// register def
+    void handleVirtualRegisterDef(MachineBasicBlock* mbb,
+                                  MachineBasicBlock::iterator mi,
+                                  LiveInterval& interval);
+
+    /// handlePhysicalRegisterDef - update intervals for a physical register
+    /// def.  If the defining instruction is a move instruction, SrcReg will be
+    /// the input register, and DestReg will be the result.  Note that Interval
+    /// may not match DestReg (it might be an alias instead).
+    ///
+    void handlePhysicalRegisterDef(MachineBasicBlock* mbb,
+                                   MachineBasicBlock::iterator mi,
+                                   LiveInterval& interval,
+                                   unsigned SrcReg, unsigned DestReg);
+
+    /// Return true if the two specified registers belong to different
+    /// register classes.  The registers may be either phys or virt regs.
+    bool differingRegisterClasses(unsigned RegA, unsigned RegB) const;
+
+    bool overlapsAliases(const LiveInterval *lhs,
+                         const LiveInterval *rhs) const;
+
+    static LiveInterval createInterval(unsigned Reg);
+
+    LiveInterval &getOrCreateInterval(unsigned reg) {
+      Reg2IntervalMap::iterator I = r2iMap_.find(reg);
+      if (I == r2iMap_.end())
+        I = r2iMap_.insert(I, std::make_pair(reg, createInterval(reg)));
+      return I->second;
+    }
 
-    inline bool operator==(const LiveIntervals::Interval& lhs,
-                           const LiveIntervals::Interval& rhs) {
-        return lhs.reg == rhs.reg;
+    /// rep - returns the representative of this register
+    unsigned rep(unsigned Reg) {
+      unsigned Rep = r2rMap_[Reg];
+      if (Rep)
+        return r2rMap_[Reg] = rep(Rep);
+      return Reg;
     }
 
-    std::ostream& operator<<(std::ostream& os,
-                             const LiveIntervals::Interval& li);
+    void printRegName(unsigned reg) const;
+  };
 
 } // End llvm namespace