#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/LiveIntervalAnalysis.h"
#include "llvm/CodeGen/RegisterCoalescer.h"
-#include "llvm/ADT/BitVector.h"
-#include <queue>
+#include "RegisterClassInfo.h"
namespace llvm {
class SimpleRegisterCoalescing;
- class LiveVariables;
+ class LiveDebugVariables;
class TargetRegisterInfo;
class TargetInstrInfo;
class VirtRegMap;
struct CopyRec {
MachineInstr *MI;
unsigned LoopDepth;
- bool isBackEdge;
- CopyRec(MachineInstr *mi, unsigned depth, bool be)
- : MI(mi), LoopDepth(depth), isBackEdge(be) {};
- };
-
- template<class SF> class JoinPriorityQueue;
-
- /// CopyRecSort - Sorting function for coalescer queue.
- ///
- struct CopyRecSort : public std::binary_function<CopyRec,CopyRec,bool> {
- JoinPriorityQueue<CopyRecSort> *JPQ;
- explicit CopyRecSort(JoinPriorityQueue<CopyRecSort> *jpq) : JPQ(jpq) {}
- CopyRecSort(const CopyRecSort &RHS) : JPQ(RHS.JPQ) {}
- bool operator()(CopyRec left, CopyRec right) const;
- };
-
- /// JoinQueue - A priority queue of copy instructions the coalescer is
- /// going to process.
- template<class SF>
- class JoinPriorityQueue {
- SimpleRegisterCoalescing *Rc;
- std::priority_queue<CopyRec, std::vector<CopyRec>, SF> Queue;
-
- public:
- explicit JoinPriorityQueue(SimpleRegisterCoalescing *rc)
- : Rc(rc), Queue(SF(this)) {}
-
- bool empty() const { return Queue.empty(); }
- void push(CopyRec R) { Queue.push(R); }
- CopyRec pop() {
- if (empty()) return CopyRec(0, 0, false);
- CopyRec R = Queue.top();
- Queue.pop();
- return R;
- }
-
- // Callbacks to SimpleRegisterCoalescing.
- unsigned getRepIntervalSize(unsigned Reg);
+ CopyRec(MachineInstr *mi, unsigned depth)
+ : MI(mi), LoopDepth(depth) {}
};
class SimpleRegisterCoalescing : public MachineFunctionPass,
const TargetRegisterInfo* tri_;
const TargetInstrInfo* tii_;
LiveIntervals *li_;
+ LiveDebugVariables *ldv_;
const MachineLoopInfo* loopInfo;
-
- BitVector allocatableRegs_;
- DenseMap<const TargetRegisterClass*, BitVector> allocatableRCRegs_;
-
- /// JoinQueue - A priority queue of copy instructions the coalescer is
- /// going to process.
- JoinPriorityQueue<CopyRecSort> *JoinQueue;
+ AliasAnalysis *AA;
+ RegisterClassInfo RegClassInfo;
/// JoinedCopies - Keep track of copies eliminated due to coalescing.
///
public:
static char ID; // Pass identifcation, replacement for typeid
- SimpleRegisterCoalescing() : MachineFunctionPass(&ID) {}
+ SimpleRegisterCoalescing() : MachineFunctionPass(ID) {
+ initializeSimpleRegisterCoalescingPass(*PassRegistry::getPassRegistry());
+ }
- struct InstrSlots {
- enum {
- LOAD = 0,
- USE = 1,
- DEF = 2,
- STORE = 3,
- NUM = 4
- };
- };
-
virtual void getAnalysisUsage(AnalysisUsage &AU) const;
virtual void releaseMemory();
bool coalesceFunction(MachineFunction &mf, RegallocQuery &) {
// This runs as an independent pass, so don't do anything.
return false;
- };
-
- /// getRepIntervalSize - Called from join priority queue sorting function.
- /// It returns the size of the interval that represent the given register.
- unsigned getRepIntervalSize(unsigned Reg) {
- if (!li_->hasInterval(Reg))
- return 0;
- return li_->getApproximateInstructionCount(li_->getInterval(Reg)) *
- LiveIntervals::InstrSlots::NUM;
}
/// 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);
- }
+ virtual void print(raw_ostream &O, const Module* = 0) const;
private:
/// joinIntervals - join compatible live intervals
/// possible to coalesce this interval, but it may be possible if other
/// things get coalesced, then it returns true by reference in 'Again'.
bool JoinCopy(CopyRec &TheCopy, bool &Again);
-
- /// 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, bool &Swapped);
-
- /// 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);
-
- /// 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;
+ /// JoinIntervals - Attempt to join these two intervals. On failure, this
+ /// returns false. The output "SrcInt" will not have been modified, so we can
+ /// use this information below to update aliases.
+ bool JoinIntervals(CoalescerPair &CP);
/// AdjustCopiesBackFrom - We found a non-trivially-coalescable copy. If
/// the source value number is defined by a copy from the destination reg
/// see if we can merge these two destination reg valno# into a single
/// value number, eliminating a copy.
- bool AdjustCopiesBackFrom(LiveInterval &IntA, LiveInterval &IntB,
- MachineInstr *CopyMI);
+ bool AdjustCopiesBackFrom(const CoalescerPair &CP, MachineInstr *CopyMI);
/// HasOtherReachingDefs - Return true if there are definitions of IntB
/// other than BValNo val# that can reach uses of AValno val# of IntA.
/// If the source value number is defined by a commutable instruction and
/// its other operand is coalesced to the copy dest register, see if we
/// can transform the copy into a noop by commuting the definition.
- bool RemoveCopyByCommutingDef(LiveInterval &IntA, LiveInterval &IntB,
- MachineInstr *CopyMI);
-
- /// TrimLiveIntervalToLastUse - If there is a last use in the same basic
- /// block as the copy instruction, trim the ive interval to the last use
- /// and return true.
- bool TrimLiveIntervalToLastUse(unsigned CopyIdx,
- MachineBasicBlock *CopyMBB,
- LiveInterval &li, const LiveRange *LR);
+ bool RemoveCopyByCommutingDef(const CoalescerPair &CP,MachineInstr *CopyMI);
/// ReMaterializeTrivialDef - If the source of a copy is defined by a trivial
/// computation, replace the copy by rematerialize the definition.
- bool ReMaterializeTrivialDef(LiveInterval &SrcInt, unsigned DstReg,
+ /// If PreserveSrcInt is true, make sure SrcInt is valid after the call.
+ bool ReMaterializeTrivialDef(LiveInterval &SrcInt, bool PreserveSrcInt,
+ unsigned DstReg, unsigned DstSubIdx,
MachineInstr *CopyMI);
- /// TurnCopyIntoImpDef - If source of the specified copy is an implicit def,
- /// turn the copy into an implicit def.
- bool TurnCopyIntoImpDef(MachineBasicBlock::iterator &I,
- MachineBasicBlock *MBB,
- unsigned DstReg, unsigned SrcReg);
-
- /// CanCoalesceWithImpDef - Returns true if the specified copy instruction
- /// from an implicit def to another register can be coalesced away.
- bool CanCoalesceWithImpDef(MachineInstr *CopyMI,
- LiveInterval &li, LiveInterval &ImpLi) const;
-
- /// RemoveCopiesFromValNo - The specified value# is defined by an implicit
- /// def and it is being removed. Turn all copies from this value# into
- /// identity copies so they will be removed.
- void RemoveCopiesFromValNo(LiveInterval &li, VNInfo *VNI);
+ /// shouldJoinPhys - Return true if a physreg copy should be joined.
+ bool shouldJoinPhys(CoalescerPair &CP);
/// isWinToJoinCrossClass - Return true if it's profitable to coalesce
/// two virtual registers from different register classes.
- bool isWinToJoinCrossClass(unsigned LargeReg, unsigned SmallReg,
- unsigned Threshold);
-
- /// HasIncompatibleSubRegDefUse - If we are trying to coalesce a virtual
- /// register with a physical register, check if any of the virtual register
- /// operand is a sub-register use or def. If so, make sure it won't result
- /// in an illegal extract_subreg or insert_subreg instruction.
- bool HasIncompatibleSubRegDefUse(MachineInstr *CopyMI,
- unsigned VirtReg, unsigned PhysReg);
-
- /// CanJoinExtractSubRegToPhysReg - Return true if it's possible to coalesce
- /// an extract_subreg where dst is a physical register, e.g.
- /// cl = EXTRACT_SUBREG reg1024, 1
- bool CanJoinExtractSubRegToPhysReg(unsigned DstReg, unsigned SrcReg,
- unsigned SubIdx, unsigned &RealDstReg);
-
- /// CanJoinInsertSubRegToPhysReg - Return true if it's possible to coalesce
- /// an insert_subreg where src is a physical register, e.g.
- /// reg1024 = INSERT_SUBREG reg1024, c1, 0
- bool CanJoinInsertSubRegToPhysReg(unsigned DstReg, unsigned SrcReg,
- unsigned SubIdx, unsigned &RealDstReg);
-
- /// RangeIsDefinedByCopyFromReg - Return true if the specified live range of
- /// the specified live interval is defined by a copy from the specified
- /// register.
- bool RangeIsDefinedByCopyFromReg(LiveInterval &li, LiveRange *LR,
- unsigned Reg);
-
- /// isBackEdgeCopy - Return true if CopyMI is a back edge copy.
- ///
- bool isBackEdgeCopy(MachineInstr *CopyMI, unsigned DstReg) const;
+ bool isWinToJoinCrossClass(unsigned SrcReg,
+ unsigned DstReg,
+ const TargetRegisterClass *SrcRC,
+ const TargetRegisterClass *DstRC,
+ const TargetRegisterClass *NewRC);
/// UpdateRegDefsUses - Replace all defs and uses of SrcReg to DstReg and
/// update the subregister number if it is not zero. If DstReg is a
/// physical register and the existing subregister number of the def / use
/// being updated is not zero, make sure to set it to the correct physical
/// subregister.
- void UpdateRegDefsUses(unsigned SrcReg, unsigned DstReg, unsigned SubIdx);
-
- /// RemoveDeadImpDef - Remove implicit_def instructions which are
- /// "re-defining" registers due to insert_subreg coalescing. e.g.
- void RemoveDeadImpDef(unsigned Reg, LiveInterval &LI);
-
- /// RemoveUnnecessaryKills - Remove kill markers that are no longer accurate
- /// due to live range lengthening as the result of coalescing.
- void RemoveUnnecessaryKills(unsigned Reg, LiveInterval &LI);
-
- /// ShortenDeadCopyLiveRange - Shorten a live range defined by a dead copy.
- /// Return true if live interval is removed.
- bool ShortenDeadCopyLiveRange(LiveInterval &li, MachineInstr *CopyMI);
-
- /// ShortenDeadCopyLiveRange - Shorten a live range as it's artificially
- /// extended by a dead copy. Mark the last use (if any) of the val# as kill
- /// as ends the live range there. If there isn't another use, then this
- /// live range is dead. Return true if live interval is removed.
- bool ShortenDeadCopySrcLiveRange(LiveInterval &li, MachineInstr *CopyMI);
+ void UpdateRegDefsUses(const CoalescerPair &CP);
/// RemoveDeadDef - If a def of a live interval is now determined dead,
/// remove the val# it defines. If the live interval becomes empty, remove
/// it as well.
bool RemoveDeadDef(LiveInterval &li, MachineInstr *DefMI);
- /// lastRegisterUse - Returns the last use of the specific register between
- /// cycles Start and End or NULL if there are no uses.
- MachineOperand *lastRegisterUse(unsigned Start, unsigned End, unsigned Reg,
- unsigned &LastUseIdx) const;
+ /// RemoveCopyFlag - If DstReg is no longer defined by CopyMI, clear the
+ /// VNInfo copy flag for DstReg and all aliases.
+ void RemoveCopyFlag(unsigned DstReg, const MachineInstr *CopyMI);
- void printRegName(unsigned reg) const;
+ /// markAsJoined - Remember that CopyMI has already been joined.
+ void markAsJoined(MachineInstr *CopyMI);
};
} // End llvm namespace