//
// The LLVM Compiler Infrastructure
//
-// This file was developed by the LLVM research group and is distributed under
-// the University of Illinois Open Source License. See LICENSE.TXT for details.
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// 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 j' > j such that v is live at j' and 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).
#include "llvm/CodeGen/LiveInterval.h"
#include "llvm/ADT/BitVector.h"
#include "llvm/ADT/DenseMap.h"
-#include "llvm/ADT/IndexedMap.h"
+#include "llvm/ADT/SmallPtrSet.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/Support/Allocator.h"
+#include <cmath>
+#include <map>
namespace llvm {
+ class AliasAnalysis;
class LiveVariables;
- class MRegisterInfo;
+ class MachineLoopInfo;
+ class TargetRegisterInfo;
+ class MachineRegisterInfo;
class TargetInstrInfo;
class TargetRegisterClass;
class VirtRegMap;
+ typedef std::pair<unsigned, MachineBasicBlock*> IdxMBBPair;
+
+ inline bool operator<(unsigned V, const IdxMBBPair &IM) {
+ return V < IM.first;
+ }
+
+ inline bool operator<(const IdxMBBPair &IM, unsigned V) {
+ return IM.first < V;
+ }
+
+ struct Idx2MBBCompare {
+ bool operator()(const IdxMBBPair &LHS, const IdxMBBPair &RHS) const {
+ return LHS.first < RHS.first;
+ }
+ };
class LiveIntervals : public MachineFunctionPass {
MachineFunction* mf_;
+ MachineRegisterInfo* mri_;
const TargetMachine* tm_;
- const MRegisterInfo* mri_;
+ const TargetRegisterInfo* tri_;
const TargetInstrInfo* tii_;
+ AliasAnalysis *aa_;
LiveVariables* lv_;
- /// MBB2IdxMap - The index of the first instruction in the specified basic
- /// block.
- std::vector<unsigned> MBB2IdxMap;
-
+ /// Special pool allocator for VNInfo's (LiveInterval val#).
+ ///
+ BumpPtrAllocator VNInfoAllocator;
+
+ /// MBB2IdxMap - The indexes of the first and last instructions in the
+ /// specified basic block.
+ std::vector<std::pair<unsigned, unsigned> > MBB2IdxMap;
+
+ /// Idx2MBBMap - Sorted list of pairs of index of first instruction
+ /// and MBB id.
+ std::vector<IdxMBBPair> Idx2MBBMap;
+
+ /// FunctionSize - The number of instructions present in the function
+ uint64_t FunctionSize;
+
typedef std::map<MachineInstr*, unsigned> Mi2IndexMap;
Mi2IndexMap mi2iMap_;
typedef std::map<unsigned, LiveInterval> Reg2IntervalMap;
Reg2IntervalMap r2iMap_;
- typedef IndexedMap<unsigned> Reg2RegMap;
- Reg2RegMap r2rMap_;
-
BitVector allocatableRegs_;
- DenseMap<const TargetRegisterClass*, BitVector> allocatableRCRegs_;
- /// JoinedLIs - Keep track which register intervals have been coalesced
- /// with other intervals.
- BitVector JoinedLIs;
+ std::vector<MachineInstr*> ClonedMIs;
public:
- static char ID; // Pass identifcation, replacement for typeid
+ static char ID; // Pass identification, replacement for typeid
LiveIntervals() : MachineFunctionPass((intptr_t)&ID) {}
- 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,
return getBaseIndex(index) + InstrSlots::STORE;
}
+ static float getSpillWeight(bool isDef, bool isUse, unsigned loopDepth) {
+ return (isDef + isUse) * powf(10.0F, (float)loopDepth);
+ }
+
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(); }
+ unsigned getNumIntervals() const { return (unsigned)r2iMap_.size(); }
LiveInterval &getInterval(unsigned reg) {
Reg2IntervalMap::iterator I = r2iMap_.find(reg);
unsigned getMBBStartIdx(MachineBasicBlock *MBB) const {
return getMBBStartIdx(MBB->getNumber());
}
-
unsigned getMBBStartIdx(unsigned MBBNo) const {
assert(MBBNo < MBB2IdxMap.size() && "Invalid MBB number!");
- return MBB2IdxMap[MBBNo];
+ return MBB2IdxMap[MBBNo].first;
+ }
+
+ /// getMBBEndIdx - Return the store index of the last instruction in the
+ /// specified MachineBasicBlock.
+ unsigned getMBBEndIdx(MachineBasicBlock *MBB) const {
+ return getMBBEndIdx(MBB->getNumber());
+ }
+ unsigned getMBBEndIdx(unsigned MBBNo) const {
+ assert(MBBNo < MBB2IdxMap.size() && "Invalid MBB number!");
+ return MBB2IdxMap[MBBNo].second;
+ }
+
+ /// getScaledIntervalSize - get the size of an interval in "units,"
+ /// where every function is composed of one thousand units. This
+ /// measure scales properly with empty index slots in the function.
+ double getScaledIntervalSize(LiveInterval& I) {
+ return (1000.0 / InstrSlots::NUM * I.getSize()) / i2miMap_.size();
+ }
+
+ /// getApproximateInstructionCount - computes an estimate of the number
+ /// of instructions in a given LiveInterval.
+ unsigned getApproximateInstructionCount(LiveInterval& I) {
+ double IntervalPercentage = getScaledIntervalSize(I) / 1000.0;
+ return IntervalPercentage * FunctionSize;
+ }
+
+ /// getMBBFromIndex - given an index in any instruction of an
+ /// MBB return a pointer the MBB
+ MachineBasicBlock* getMBBFromIndex(unsigned index) const {
+ std::vector<IdxMBBPair>::const_iterator I =
+ std::lower_bound(Idx2MBBMap.begin(), Idx2MBBMap.end(), index);
+ // Take the pair containing the index
+ std::vector<IdxMBBPair>::const_iterator J =
+ ((I != Idx2MBBMap.end() && I->first > index) ||
+ (I == Idx2MBBMap.end() && Idx2MBBMap.size()>0)) ? (I-1): I;
+
+ assert(J != Idx2MBBMap.end() && J->first < index+1 &&
+ index <= getMBBEndIdx(J->second) &&
+ "index does not correspond to an MBB");
+ return J->second;
}
/// getInstructionIndex - returns the base index of instr
"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);
+ /// conflictsWithPhysRegDef - Returns true if the specified register
+ /// is defined during the duration of the specified interval.
+ bool conflictsWithPhysRegDef(const LiveInterval &li, VirtRegMap &vrm,
+ unsigned reg);
- virtual void getAnalysisUsage(AnalysisUsage &AU) const;
- virtual void releaseMemory();
+ /// findLiveInMBBs - Given a live range, if the value of the range
+ /// is live in any MBB returns true as well as the list of basic blocks
+ /// in which the value is live.
+ bool findLiveInMBBs(const LiveRange &LR,
+ SmallVectorImpl<MachineBasicBlock*> &MBBs) const;
- /// runOnMachineFunction - pass entry point
- virtual bool runOnMachineFunction(MachineFunction&);
+ // Interval creation
- /// 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);
+ 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;
+ }
+
+ /// addLiveRangeToEndOfBlock - Given a register and an instruction,
+ /// adds a live range from that instruction to the end of its MBB.
+ LiveRange addLiveRangeToEndOfBlock(unsigned reg,
+ MachineInstr* startInst);
+
+ // Interval removal
+
+ void removeInterval(unsigned Reg) {
+ r2iMap_.erase(Reg);
}
- private:
/// isRemoved - returns true if the specified machine instr has been
/// removed.
bool isRemoved(MachineInstr* instr) const {
mi2iMap_.erase(mi2i);
}
}
-
+
+ /// ReplaceMachineInstrInMaps - Replacing a machine instr with a new one in
+ /// maps used by register allocator.
+ void ReplaceMachineInstrInMaps(MachineInstr *MI, MachineInstr *NewMI) {
+ Mi2IndexMap::iterator mi2i = mi2iMap_.find(MI);
+ if (mi2i == mi2iMap_.end())
+ return;
+ i2miMap_[mi2i->second/InstrSlots::NUM] = NewMI;
+ Mi2IndexMap::iterator it = mi2iMap_.find(MI);
+ assert(it != mi2iMap_.end() && "Invalid instruction!");
+ unsigned Index = it->second;
+ mi2iMap_.erase(it);
+ mi2iMap_[NewMI] = Index;
+ }
+
+ BumpPtrAllocator& getVNInfoAllocator() { return VNInfoAllocator; }
+
+ /// getVNInfoSourceReg - Helper function that parses the specified VNInfo
+ /// copy field and returns the source register that defines it.
+ unsigned getVNInfoSourceReg(const VNInfo *VNI) const;
+
+ 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);
+ }
+
+ /// addIntervalsForSpills - Create new intervals for spilled defs / uses of
+ /// the given interval. FIXME: It also returns the weight of the spill slot
+ /// (if any is created) by reference. This is temporary.
+ std::vector<LiveInterval*>
+ addIntervalsForSpills(const LiveInterval& i,
+ const MachineLoopInfo *loopInfo, VirtRegMap& vrm,
+ float &SSWeight);
+
+ /// spillPhysRegAroundRegDefsUses - Spill the specified physical register
+ /// around all defs and uses of the specified interval.
+ void spillPhysRegAroundRegDefsUses(const LiveInterval &li,
+ unsigned PhysReg, VirtRegMap &vrm);
+
+ /// isReMaterializable - Returns true if every definition of MI of every
+ /// val# of the specified interval is re-materializable. Also returns true
+ /// by reference if all of the defs are load instructions.
+ bool isReMaterializable(const LiveInterval &li, bool &isLoad);
+
+ /// getRepresentativeReg - Find the largest super register of the specified
+ /// physical register.
+ unsigned getRepresentativeReg(unsigned Reg) const;
+
+ /// getNumConflictsWithPhysReg - Return the number of uses and defs of the
+ /// specified interval that conflicts with the specified physical register.
+ unsigned getNumConflictsWithPhysReg(const LiveInterval &li,
+ unsigned PhysReg) const;
+
+ /// computeNumbering - Compute the index numbering.
+ void computeNumbering();
+
+ private:
/// 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, bool PhysOnly = false);
-
- /// 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,
- bool PhysOnly = false);
-
- /// 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);
+ MachineOperand& MO, unsigned MOIdx);
/// handleVirtualRegisterDef - update intervals for a virtual
/// register def
void handleVirtualRegisterDef(MachineBasicBlock *MBB,
MachineBasicBlock::iterator MI,
- unsigned MIIdx,
- LiveInterval& interval);
+ unsigned MIIdx, MachineOperand& MO,
+ unsigned MOIdx, LiveInterval& interval);
/// handlePhysicalRegisterDef - update intervals for a physical register
/// def.
void handlePhysicalRegisterDef(MachineBasicBlock* mbb,
MachineBasicBlock::iterator mi,
- unsigned MIIdx,
+ unsigned MIIdx, MachineOperand& MO,
LiveInterval &interval,
- unsigned SrcReg);
+ MachineInstr *CopyMI);
/// handleLiveInRegister - Create interval for a livein register.
void handleLiveInRegister(MachineBasicBlock* mbb,
unsigned MIIdx,
LiveInterval &interval, bool isAlias = false);
- /// 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);
-
- /// findDefOperand - Returns the MachineOperand that is a def of the specific
- /// register. It returns NULL if the def is not found.
- MachineOperand *findDefOperand(MachineInstr *MI, unsigned Reg);
-
- /// unsetRegisterKill - Unset IsKill property of all uses of the specific
- /// register of the specific instruction.
- void unsetRegisterKill(MachineInstr *MI, unsigned Reg);
+ /// getReMatImplicitUse - If the remat definition MI has one (for now, we
+ /// only allow one) virtual register operand, then its uses are implicitly
+ /// using the register. Returns the virtual register.
+ unsigned getReMatImplicitUse(const LiveInterval &li,
+ MachineInstr *MI) const;
+
+ /// isValNoAvailableAt - Return true if the val# of the specified interval
+ /// which reaches the given instruction also reaches the specified use
+ /// index.
+ bool isValNoAvailableAt(const LiveInterval &li, MachineInstr *MI,
+ unsigned UseIdx) const;
+
+ /// isReMaterializable - Returns true if the definition MI of the specified
+ /// val# of the specified interval is re-materializable. Also returns true
+ /// by reference if the def is a load.
+ bool isReMaterializable(const LiveInterval &li, const VNInfo *ValNo,
+ MachineInstr *MI, bool &isLoad);
+
+ /// tryFoldMemoryOperand - Attempts to fold either a spill / restore from
+ /// slot / to reg or any rematerialized load into ith operand of specified
+ /// MI. If it is successul, MI is updated with the newly created MI and
+ /// returns true.
+ bool tryFoldMemoryOperand(MachineInstr* &MI, VirtRegMap &vrm,
+ MachineInstr *DefMI, unsigned InstrIdx,
+ SmallVector<unsigned, 2> &Ops,
+ bool isSS, int Slot, unsigned Reg);
+
+ /// canFoldMemoryOperand - Return true if the specified load / store
+ /// folding is possible.
+ bool canFoldMemoryOperand(MachineInstr *MI,
+ SmallVector<unsigned, 2> &Ops,
+ bool ReMatLoadSS) const;
+
+ /// anyKillInMBBAfterIdx - Returns true if there is a kill of the specified
+ /// VNInfo that's after the specified index but is within the basic block.
+ bool anyKillInMBBAfterIdx(const LiveInterval &li, const VNInfo *VNI,
+ MachineBasicBlock *MBB, unsigned Idx) const;
+
+ /// intervalIsInOneMBB - Returns true if the specified interval is entirely
+ /// within a single basic block.
+ bool intervalIsInOneMBB(const LiveInterval &li) const;
+
+ /// hasAllocatableSuperReg - Return true if the specified physical register
+ /// has any super register that's allocatable.
+ bool hasAllocatableSuperReg(unsigned Reg) const;
+
+ /// SRInfo - Spill / restore info.
+ struct SRInfo {
+ int index;
+ unsigned vreg;
+ bool canFold;
+ SRInfo(int i, unsigned vr, bool f) : index(i), vreg(vr), canFold(f) {};
+ };
- /// hasRegisterDef - True if the instruction defines the specific register.
- ///
- bool hasRegisterDef(MachineInstr *MI, unsigned Reg);
+ bool alsoFoldARestore(int Id, int index, unsigned vr,
+ BitVector &RestoreMBBs,
+ std::map<unsigned,std::vector<SRInfo> >&RestoreIdxes);
+ void eraseRestoreInfo(int Id, int index, unsigned vr,
+ BitVector &RestoreMBBs,
+ std::map<unsigned,std::vector<SRInfo> >&RestoreIdxes);
+
+ /// handleSpilledImpDefs - Remove IMPLICIT_DEF instructions which are being
+ /// spilled and create empty intervals for their uses.
+ void handleSpilledImpDefs(const LiveInterval &li, VirtRegMap &vrm,
+ const TargetRegisterClass* rc,
+ std::vector<LiveInterval*> &NewLIs);
+
+ /// rewriteImplicitOps - Rewrite implicit use operands of MI (i.e. uses of
+ /// interval on to-be re-materialized operands of MI) with new register.
+ void rewriteImplicitOps(const LiveInterval &li,
+ MachineInstr *MI, unsigned NewVReg, VirtRegMap &vrm);
+
+ /// rewriteInstructionForSpills, rewriteInstructionsForSpills - Helper
+ /// functions for addIntervalsForSpills to rewrite uses / defs for the given
+ /// live range.
+ bool rewriteInstructionForSpills(const LiveInterval &li, const VNInfo *VNI,
+ bool TrySplit, unsigned index, unsigned end, MachineInstr *MI,
+ MachineInstr *OrigDefMI, MachineInstr *DefMI, unsigned Slot, int LdSlot,
+ bool isLoad, bool isLoadSS, bool DefIsReMat, bool CanDelete,
+ VirtRegMap &vrm, const TargetRegisterClass* rc,
+ SmallVector<int, 4> &ReMatIds, const MachineLoopInfo *loopInfo,
+ unsigned &NewVReg, unsigned ImpUse, bool &HasDef, bool &HasUse,
+ std::map<unsigned,unsigned> &MBBVRegsMap,
+ std::vector<LiveInterval*> &NewLIs, float &SSWeight);
+ void rewriteInstructionsForSpills(const LiveInterval &li, bool TrySplit,
+ LiveInterval::Ranges::const_iterator &I,
+ MachineInstr *OrigDefMI, MachineInstr *DefMI, unsigned Slot, int LdSlot,
+ bool isLoad, bool isLoadSS, bool DefIsReMat, bool CanDelete,
+ VirtRegMap &vrm, const TargetRegisterClass* rc,
+ SmallVector<int, 4> &ReMatIds, const MachineLoopInfo *loopInfo,
+ BitVector &SpillMBBs,
+ std::map<unsigned,std::vector<SRInfo> > &SpillIdxes,
+ BitVector &RestoreMBBs,
+ std::map<unsigned,std::vector<SRInfo> > &RestoreIdxes,
+ std::map<unsigned,unsigned> &MBBVRegsMap,
+ std::vector<LiveInterval*> &NewLIs, float &SSWeight);
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;
- }
-
void printRegName(unsigned reg) const;
};
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