-//===-- 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 "llvm/CodeGen/MachineBasicBlock.h"
-#include <iostream>
-#include <map>
+#include "LiveInterval.h"
namespace llvm {
- class LiveVariables;
- class MRegisterInfo;
+ class LiveVariables;
+ class MRegisterInfo;
+ 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
- unsigned weight; // weight of this interval (number of uses)
- Ranges ranges; // the ranges this register is valid
-
- Interval(unsigned r);
-
- unsigned start() const {
- assert(!ranges.empty() && "empty interval for register");
- return ranges.front().first;
- }
-
- unsigned end() const {
- assert(!ranges.empty() && "empty interval for register");
- return ranges.back().second;
- }
-
- bool expiredAt(unsigned index) const {
- return end() <= index;
- }
-
- bool liveAt(unsigned index) const;
-
- bool overlaps(const Interval& other) const;
-
- void addRange(unsigned start, unsigned end);
-
- private:
- void mergeRangesForward(Ranges::iterator it);
-
- void 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::vector<Interval> Intervals;
- typedef std::vector<MachineBasicBlock*> MachineBasicBlockPtrs;
-
- private:
- MachineFunction* mf_;
- const TargetMachine* tm_;
- const MRegisterInfo* mri_;
- MachineBasicBlock* currentMbb_;
- MachineBasicBlock::iterator currentInstr_;
- LiveVariables* lv_;
-
- std::vector<bool> allocatableRegisters_;
-
- typedef std::map<unsigned, MachineBasicBlock*> MbbIndex2MbbMap;
- MbbIndex2MbbMap mbbi2mbbMap_;
-
- typedef std::map<MachineInstr*, unsigned> Mi2IndexMap;
- Mi2IndexMap mi2iMap_;
-
- typedef std::map<unsigned, unsigned> Reg2IntervalMap;
- Reg2IntervalMap r2iMap_;
-
- Intervals intervals_;
-
- public:
- virtual void getAnalysisUsage(AnalysisUsage &AU) const;
- 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;
- }
-
- private:
- /// runOnMachineFunction - pass entry point
- bool runOnMachineFunction(MachineFunction&);
-
- /// computeIntervals - compute live intervals
- void computeIntervals();
-
-
- /// 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,
- unsigned reg);
+ class LiveIntervals : public MachineFunctionPass {
+ MachineFunction* mf_;
+ const TargetMachine* tm_;
+ const MRegisterInfo* mri_;
+ LiveVariables* lv_;
+
+ typedef std::map<MachineInstr*, unsigned> Mi2IndexMap;
+ Mi2IndexMap mi2iMap_;
+
+ typedef std::vector<MachineInstr*> Index2MiMap;
+ Index2MiMap i2miMap_;
+
+ typedef std::map<unsigned, LiveInterval> Reg2IntervalMap;
+ Reg2IntervalMap r2iMap_;
+
+ typedef DenseMap<unsigned> Reg2RegMap;
+ Reg2RegMap r2rMap_;
- /// handlePhysicalRegisterDef - update intervals for a
- /// physical register def
- void handlePhysicalRegisterDef(MachineBasicBlock* mbb,
- MachineBasicBlock::iterator mi,
- unsigned reg);
-
- unsigned getInstructionIndex(MachineInstr* instr) const;
+ std::vector<bool> allocatableRegs_;
- void printRegName(unsigned reg) const;
+ public:
+ struct InstrSlots
+ {
+ enum {
+ LOAD = 0,
+ USE = 1,
+ DEF = 2,
+ STORE = 3,
+ NUM = 4,
+ };
};
- inline bool operator==(const LiveIntervals::Interval& lhs,
- const LiveIntervals::Interval& rhs) {
- return lhs.reg == rhs.reg;
+ 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;
+ }
+
+ 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;
+ }
+
+ 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;
+ }
+
+ /// 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;
+ }
+
+ /// 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];
+ }
+
+ 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
+ void handlePhysicalRegisterDef(MachineBasicBlock* mbb,
+ MachineBasicBlock::iterator mi,
+ LiveInterval& interval);
+
+ /// 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;
+ }
+
+ /// 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