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author | David Goodwin <david_goodwin@apple.com> | 2009-10-26 22:31:16 +0000 |
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committer | David Goodwin <david_goodwin@apple.com> | 2009-10-26 22:31:16 +0000 |
commit | e10deca33e74a7c70ab585f78eee3fb52937f668 (patch) | |
tree | 040756b08ba58b1bd3d181e4fee5cb2d662925ec /lib/CodeGen/AggressiveAntiDepBreaker.h | |
parent | 06d4033a354115904e9df23608f9a7cd543d5dbc (diff) | |
download | llvm-e10deca33e74a7c70ab585f78eee3fb52937f668.tar.gz llvm-e10deca33e74a7c70ab585f78eee3fb52937f668.tar.bz2 llvm-e10deca33e74a7c70ab585f78eee3fb52937f668.tar.xz |
Allow the aggressive anti-dep breaker to process the same region multiple times. This is necessary because new anti-dependencies are exposed when "current" ones are broken.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@85166 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/CodeGen/AggressiveAntiDepBreaker.h')
-rw-r--r-- | lib/CodeGen/AggressiveAntiDepBreaker.h | 103 |
1 files changed, 69 insertions, 34 deletions
diff --git a/lib/CodeGen/AggressiveAntiDepBreaker.h b/lib/CodeGen/AggressiveAntiDepBreaker.h index e6b7268e77..f4a05290c0 100644 --- a/lib/CodeGen/AggressiveAntiDepBreaker.h +++ b/lib/CodeGen/AggressiveAntiDepBreaker.h @@ -28,11 +28,12 @@ #include "llvm/ADT/SmallSet.h" namespace llvm { - class AggressiveAntiDepBreaker : public AntiDepBreaker { - MachineFunction& MF; - MachineRegisterInfo &MRI; - const TargetRegisterInfo *TRI; - + /// Class AggressiveAntiDepState + /// Contains all the state necessary for anti-dep breaking. We place + /// into a separate class so be can conveniently save/restore it to + /// enable multi-pass anti-dep breaking. + class AggressiveAntiDepState { + public: /// RegisterReference - Information about a register reference /// within a liverange typedef struct { @@ -42,59 +43,43 @@ namespace llvm { const TargetRegisterClass *RC; } RegisterReference; - /// AllocatableSet - The set of allocatable registers. - /// We'll be ignoring anti-dependencies on non-allocatable registers, - /// because they may not be safe to break. - const BitVector AllocatableSet; - + private: /// GroupNodes - Implements a disjoint-union data structure to /// form register groups. A node is represented by an index into /// the vector. A node can "point to" itself to indicate that it /// is the parent of a group, or point to another node to indicate /// that it is a member of the same group as that node. std::vector<unsigned> GroupNodes; - + /// GroupNodeIndices - For each register, the index of the GroupNode /// currently representing the group that the register belongs to. /// Register 0 is always represented by the 0 group, a group /// composed of registers that are not eligible for anti-aliasing. unsigned GroupNodeIndices[TargetRegisterInfo::FirstVirtualRegister]; - - /// RegRegs - Map registers to all their references within a live range. + + /// RegRefs - Map registers to all their references within a live range. std::multimap<unsigned, RegisterReference> RegRefs; - + /// KillIndices - The index of the most recent kill (proceding bottom-up), /// or ~0u if the register is not live. unsigned KillIndices[TargetRegisterInfo::FirstVirtualRegister]; - + /// DefIndices - The index of the most recent complete def (proceding bottom /// up), or ~0u if the register is live. unsigned DefIndices[TargetRegisterInfo::FirstVirtualRegister]; public: - AggressiveAntiDepBreaker(MachineFunction& MFi); - ~AggressiveAntiDepBreaker(); + AggressiveAntiDepState(MachineBasicBlock *BB); - /// Start - Initialize anti-dep breaking for a new basic block. - void StartBlock(MachineBasicBlock *BB); - - /// BreakAntiDependencies - Identifiy anti-dependencies along the critical path - /// of the ScheduleDAG and break them by renaming registers. - /// - unsigned BreakAntiDependencies(std::vector<SUnit>& SUnits, - MachineBasicBlock::iterator& Begin, - MachineBasicBlock::iterator& End, - unsigned InsertPosIndex); + /// GetKillIndices - Return the kill indices. + unsigned *GetKillIndices() { return KillIndices; } - /// Observe - Update liveness information to account for the current - /// instruction, which will not be scheduled. - /// - void Observe(MachineInstr *MI, unsigned Count, unsigned InsertPosIndex); + /// GetDefIndices - Return the define indices. + unsigned *GetDefIndices() { return DefIndices; } - /// Finish - Finish anti-dep breaking for a basic block. - void FinishBlock(); + /// GetRegRefs - Return the RegRefs map. + std::multimap<unsigned, RegisterReference>& GetRegRefs() { return RegRefs; } - private: // GetGroup - Get the group for a register. The returned value is // the index of the GroupNode representing the group. unsigned GetGroup(unsigned Reg); @@ -115,7 +100,57 @@ namespace llvm { /// IsLive - Return true if Reg is live bool IsLive(unsigned Reg); + }; + + + /// Class AggressiveAntiDepBreaker + class AggressiveAntiDepBreaker : public AntiDepBreaker { + MachineFunction& MF; + MachineRegisterInfo &MRI; + const TargetRegisterInfo *TRI; + + /// AllocatableSet - The set of allocatable registers. + /// We'll be ignoring anti-dependencies on non-allocatable registers, + /// because they may not be safe to break. + const BitVector AllocatableSet; + + /// State - The state used to identify and rename anti-dependence + /// registers. + AggressiveAntiDepState *State; + + /// SavedState - The state for the start of an anti-dep + /// region. Used to restore the state at the beginning of each + /// pass + AggressiveAntiDepState *SavedState; + + public: + AggressiveAntiDepBreaker(MachineFunction& MFi); + ~AggressiveAntiDepBreaker(); + /// GetMaxTrials - As anti-dependencies are broken, additional + /// dependencies may be exposed, so multiple passes are required. + unsigned GetMaxTrials(); + + /// Start - Initialize anti-dep breaking for a new basic block. + void StartBlock(MachineBasicBlock *BB); + + /// BreakAntiDependencies - Identifiy anti-dependencies along the critical path + /// of the ScheduleDAG and break them by renaming registers. + /// + unsigned BreakAntiDependencies(std::vector<SUnit>& SUnits, + MachineBasicBlock::iterator& Begin, + MachineBasicBlock::iterator& End, + unsigned InsertPosIndex); + + /// Observe - Update liveness information to account for the current + /// instruction, which will not be scheduled. + /// + void Observe(MachineInstr *MI, unsigned Count, unsigned InsertPosIndex); + + /// Finish - Finish anti-dep breaking for a basic block. + void FinishBlock(); + + private: /// IsImplicitDefUse - Return true if MO represents a register /// that is both implicitly used and defined in MI bool IsImplicitDefUse(MachineInstr *MI, MachineOperand& MO); |