-//===-- 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/CodeGen/MachineFunctionPass.h"
-#include "llvm/CodeGen/MachineBasicBlock.h"
-#include <iostream>
-#include <map>
+#include "llvm/CodeGen/LiveInterval.h"
+#include "llvm/ADT/BitVector.h"
+#include "llvm/ADT/IndexedMap.h"
namespace llvm {
- class LiveVariables;
- class MRegisterInfo;
-
- 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
- Ranges ranges; // the ranges this register is valid
-
- Interval(unsigned r)
- : reg(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 expired(unsigned index) const {
- return end() <= index;
- }
-
- 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);
-
- /// handlePhysicalRegisterDef - update intervals for a
- /// physical register def
- void handlePhysicalRegisterDef(MachineBasicBlock* mbb,
- MachineBasicBlock::iterator mi,
- unsigned reg);
-
- unsigned getInstructionIndex(MachineInstr* instr) const;
-
- void printRegName(unsigned reg) const;
+ class LiveVariables;
+ class MRegisterInfo;
+ class TargetInstrInfo;
+ class VirtRegMap;
+
+ class LiveIntervals : public MachineFunctionPass {
+ MachineFunction* mf_;
+ const TargetMachine* tm_;
+ const MRegisterInfo* mri_;
+ const TargetInstrInfo* tii_;
+ LiveVariables* lv_;
+
+ /// MBB2IdxMap - The index of the first instruction in the specified basic
+ /// block.
+ std::vector<unsigned> MBB2IdxMap;
+
+ typedef std::map<MachineInstr*, unsigned> Mi2IndexMap;
+ Mi2IndexMap mi2iMap_;
+
+ typedef std::vector<MachineInstr*> Index2MiMap;
+ Index2MiMap i2miMap_;
+
+ typedef std::map<unsigned, LiveInterval> Reg2IntervalMap;
+ Reg2IntervalMap r2iMap_;
+
+ typedef IndexedMap<unsigned> Reg2RegMap;
+ Reg2RegMap r2rMap_;
+
+ BitVector allocatableRegs_;
+
+ /// JoinedLIs - Keep track which register intervals have been coalesced
+ /// with other intervals.
+ BitVector JoinedLIs;
+
+ public:
+ struct CopyRec {
+ MachineInstr *MI;
+ unsigned SrcReg, DstReg;
+ };
+ CopyRec getCopyRec(MachineInstr *MI, unsigned SrcReg, unsigned DstReg) {
+ CopyRec R;
+ R.MI = MI;
+ R.SrcReg = SrcReg;
+ R.DstReg = DstReg;
+ return R;
+ }
+ 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;
+ }
+
+ bool hasInterval(unsigned reg) const {
+ return r2iMap_.count(reg);
+ }
+
+ /// getMBBStartIdx - Return the base index of the first instruction in the
+ /// specified MachineBasicBlock.
+ unsigned getMBBStartIdx(MachineBasicBlock *MBB) const {
+ return getMBBStartIdx(MBB->getNumber());
+ }
+
+ unsigned getMBBStartIdx(unsigned MBBNo) const {
+ assert(MBBNo < MBB2IdxMap.size() && "Invalid MBB number!");
+ return MBB2IdxMap[MBBNo];
+ }
+
+ /// 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);
+
+ /// CreateNewLiveInterval - Create a new live interval with the given live
+ /// ranges. The new live interval will have an infinite spill weight.
+ LiveInterval &CreateNewLiveInterval(const LiveInterval *LI,
+ const std::vector<LiveRange> &LRs);
+
+ 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;
+ void print(std::ostream *O, const Module* M = 0) const {
+ if (O) print(*O, M);
+ }
+
+ private:
+ /// isRemoved - returns true if the specified machine instr has been
+ /// removed.
+ bool isRemoved(MachineInstr* instr) const {
+ return !mi2iMap_.count(instr);
+ }
+
+ /// RemoveMachineInstrFromMaps - This marks the specified machine instr as
+ /// deleted.
+ void RemoveMachineInstrFromMaps(MachineInstr *MI) {
+ // remove index -> MachineInstr and
+ // MachineInstr -> index mappings
+ Mi2IndexMap::iterator mi2i = mi2iMap_.find(MI);
+ if (mi2i != mi2iMap_.end()) {
+ i2miMap_[mi2i->second/InstrSlots::NUM] = 0;
+ mi2iMap_.erase(mi2i);
+ }
+ }
+
+ /// computeIntervals - Compute live intervals.
+ void computeIntervals();
+
+ /// joinIntervals - join compatible live intervals
+ void joinIntervals();
+
+ /// CopyCoallesceInMBB - Coallsece copies in the specified MBB, putting
+ /// copies that cannot yet be coallesced into the "TryAgain" list.
+ void CopyCoallesceInMBB(MachineBasicBlock *MBB,
+ std::vector<CopyRec> &TryAgain);
+
+ /// JoinCopy - Attempt to join intervals corresponding to SrcReg/DstReg,
+ /// which are the src/dst of the copy instruction CopyMI. This returns true
+ /// if the copy was successfully coallesced away, or if it is never possible
+ /// to coallesce these this copy, due to register constraints. It returns
+ /// false if it is not currently possible to coallesce this interval, but
+ /// it may be possible if other things get coallesced.
+ bool JoinCopy(MachineInstr *CopyMI, unsigned SrcReg, unsigned DstReg);
+
+ /// JoinIntervals - Attempt to join these two intervals. On failure, this
+ /// returns false. Otherwise, if one of the intervals being joined is a
+ /// physreg, this method always canonicalizes DestInt to be it. The output
+ /// "SrcInt" will not have been modified, so we can use this information
+ /// below to update aliases.
+ bool JoinIntervals(LiveInterval &LHS, LiveInterval &RHS);
+
+ /// SimpleJoin - Attempt to join the specified interval into this one. The
+ /// caller of this method must guarantee that the RHS only contains a single
+ /// value number and that the RHS is not defined by a copy from this
+ /// interval. This returns false if the intervals are not joinable, or it
+ /// joins them and returns true.
+ bool SimpleJoin(LiveInterval &LHS, LiveInterval &RHS);
+
+ /// handleRegisterDef - update intervals for a register def
+ /// (calls handlePhysicalRegisterDef and
+ /// handleVirtualRegisterDef)
+ void handleRegisterDef(MachineBasicBlock *MBB,
+ MachineBasicBlock::iterator MI, unsigned MIIdx,
+ unsigned reg);
+
+ /// handleVirtualRegisterDef - update intervals for a virtual
+ /// register def
+ void handleVirtualRegisterDef(MachineBasicBlock *MBB,
+ MachineBasicBlock::iterator MI,
+ unsigned MIIdx,
+ LiveInterval& interval);
+
+ /// handlePhysicalRegisterDef - update intervals for a physical register
+ /// def.
+ void handlePhysicalRegisterDef(MachineBasicBlock* mbb,
+ MachineBasicBlock::iterator mi,
+ unsigned MIIdx,
+ LiveInterval &interval,
+ unsigned SrcReg);
+
+ /// handleLiveInRegister - Create interval for a livein register.
+ void handleLiveInRegister(MachineBasicBlock* mbb,
+ unsigned MIIdx,
+ 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 AdjustCopiesBackFrom(LiveInterval &IntA, LiveInterval &IntB,
+ MachineInstr *CopyMI);
+
+ /// lastRegisterUse - Returns the last use of the specific register between
+ /// cycles Start and End. It also returns the use operand by reference. It
+ /// returns NULL if there are no uses.
+ MachineInstr *lastRegisterUse(unsigned Reg, unsigned Start, unsigned End,
+ MachineOperand *&MOU);
+
+ /// unsetRegisterKill - Unset IsKill property of all uses of the specific
+ /// register of the specific instruction.
+ void unsetRegisterKill(MachineInstr *MI, unsigned Reg);
+
+ /// hasRegisterDef - True if the instruction defines the specific register.
+ ///
+ bool hasRegisterDef(MachineInstr *MI, unsigned Reg);
+
+ static LiveInterval createInterval(unsigned Reg);
+
+ void removeInterval(unsigned Reg) {
+ r2iMap_.erase(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