//
//===----------------------------------------------------------------------===//
-#include "RegisterClassInfo.h"
-#include "llvm/Support/IncludeFile.h"
-#include "llvm/CodeGen/LiveInterval.h"
-#include "llvm/ADT/SmallPtrSet.h"
-
#ifndef LLVM_CODEGEN_REGISTER_COALESCER_H
#define LLVM_CODEGEN_REGISTER_COALESCER_H
namespace llvm {
- class MachineFunction;
- class RegallocQuery;
- class AnalysisUsage;
class MachineInstr;
class TargetRegisterInfo;
class TargetRegisterClass;
class TargetInstrInfo;
- class LiveDebugVariables;
- class VirtRegMap;
- class MachineLoopInfo;
-
- class CoalescerPair;
-
- /// An abstract interface for register coalescers. Coalescers must
- /// implement this interface to be part of the coalescer analysis
- /// group.
- class RegisterCoalescer : public MachineFunctionPass {
- MachineFunction* mf_;
- MachineRegisterInfo* mri_;
- const TargetMachine* tm_;
- const TargetRegisterInfo* tri_;
- const TargetInstrInfo* tii_;
- LiveIntervals *li_;
- LiveDebugVariables *ldv_;
- const MachineLoopInfo* loopInfo;
- AliasAnalysis *AA;
- RegisterClassInfo RegClassInfo;
-
- /// JoinedCopies - Keep track of copies eliminated due to coalescing.
- ///
- SmallPtrSet<MachineInstr*, 32> JoinedCopies;
-
- /// ReMatCopies - Keep track of copies eliminated due to remat.
- ///
- SmallPtrSet<MachineInstr*, 32> ReMatCopies;
-
- /// ReMatDefs - Keep track of definition instructions which have
- /// been remat'ed.
- SmallPtrSet<MachineInstr*, 8> ReMatDefs;
-
- /// joinIntervals - join compatible live intervals
- void joinIntervals();
-
- /// CopyCoalesceInMBB - Coalesce copies in the specified MBB, putting
- /// copies that cannot yet be coalesced into the "TryAgain" list.
- void CopyCoalesceInMBB(MachineBasicBlock *MBB,
- std::vector<MachineInstr*> &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 coalesced away. If it is not currently
- /// 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(MachineInstr *TheCopy, bool &Again);
-
- /// 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(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.
- bool HasOtherReachingDefs(LiveInterval &IntA, LiveInterval &IntB,
- VNInfo *AValNo, VNInfo *BValNo);
-
- /// RemoveCopyByCommutingDef - We found a non-trivially-coalescable copy.
- /// 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(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.
- /// If PreserveSrcInt is true, make sure SrcInt is valid after the call.
- bool ReMaterializeTrivialDef(LiveInterval &SrcInt, bool PreserveSrcInt,
- unsigned DstReg, unsigned DstSubIdx,
- MachineInstr *CopyMI);
-
- /// 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 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(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);
-
- /// 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);
-
- /// markAsJoined - Remember that CopyMI has already been joined.
- void markAsJoined(MachineInstr *CopyMI);
-
- /// eliminateUndefCopy - Handle copies of undef values.
- bool eliminateUndefCopy(MachineInstr *CopyMI, const CoalescerPair &CP);
-
- public:
- static char ID; // Class identification, replacement for typeinfo
- RegisterCoalescer() : MachineFunctionPass(ID) {
- initializeRegisterCoalescerPass(*PassRegistry::getPassRegistry());
- }
-
- /// Register allocators must call this from their own
- /// getAnalysisUsage to cover the case where the coalescer is not
- /// a Pass in the proper sense and isn't managed by PassManager.
- /// PassManager needs to know which analyses to make available and
- /// which to invalidate when running the register allocator or any
- /// pass that might call coalescing. The long-term solution is to
- /// allow hierarchies of PassManagers.
- 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(raw_ostream &O, const Module* = 0) const;
- };
/// CoalescerPair - A helper class for register coalescers. When deciding if
/// two registers can be coalesced, CoalescerPair can determine if a copy
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