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author | Rafael Espindola <rafael.espindola@gmail.com> | 2011-06-26 22:34:10 +0000 |
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committer | Rafael Espindola <rafael.espindola@gmail.com> | 2011-06-26 22:34:10 +0000 |
commit | 5b220213bfe9c37c2bb41a7ae0804e06a14f1007 (patch) | |
tree | f5498354354616f9a6c20c65c122bd3f6ebda753 /lib/CodeGen/RegisterCoalescer.h | |
parent | 655739de7b09dcfecd9f3e5f1734e53ec90a19f3 (diff) | |
download | llvm-5b220213bfe9c37c2bb41a7ae0804e06a14f1007.tar.gz llvm-5b220213bfe9c37c2bb41a7ae0804e06a14f1007.tar.bz2 llvm-5b220213bfe9c37c2bb41a7ae0804e06a14f1007.tar.xz |
There is only one register coalescer. Merge it into the base class and
remove the analysis group.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@133899 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/CodeGen/RegisterCoalescer.h')
-rw-r--r-- | lib/CodeGen/RegisterCoalescer.h | 255 |
1 files changed, 118 insertions, 137 deletions
diff --git a/lib/CodeGen/RegisterCoalescer.h b/lib/CodeGen/RegisterCoalescer.h index 739a4c3711..ec83b81882 100644 --- a/lib/CodeGen/RegisterCoalescer.h +++ b/lib/CodeGen/RegisterCoalescer.h @@ -29,24 +29,126 @@ namespace llvm { class TargetRegisterInfo; class TargetRegisterClass; class TargetInstrInfo; - class SimpleRegisterCoalescing; 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 { + 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); + public: static char ID; // Class identification, replacement for typeinfo - RegisterCoalescer() {} - virtual ~RegisterCoalescer(); // We want to be subclassed + RegisterCoalescer() : MachineFunctionPass(ID) { + initializeRegisterCoalescerPass(*PassRegistry::getPassRegistry()); + } /// Run the coalescer on this function, providing interference /// data to query. Return whether we removed any copies. virtual bool coalesceFunction(MachineFunction &mf, - RegallocQuery &ifd) = 0; + RegallocQuery &ifd) { + // This runs as an independent pass, so don't do anything. + return false; + } /// Reset state. Can be used to allow a coalescer run by /// PassManager to be run again by the register allocator. @@ -59,8 +161,16 @@ namespace llvm { /// 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 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; + }; /// An abstract interface for register allocators to interact with /// coalescers @@ -82,7 +192,7 @@ namespace llvm { /// /// allocation doesn't pre-compute interference information it's /// /// the best we can do. Coalescers are always free to ignore this /// /// and implement their own discovery strategy. See - /// /// SimpleRegisterCoalescing for an example. + /// /// RegisterCoalescer for an example. /// void getInterferences(IntervalSet &interferences, /// const LiveInterval &a) const { /// for(LiveIntervals::const_iterator iv = li.begin(), @@ -236,135 +346,6 @@ namespace llvm { /// getNewRC - Return the register class of the coalesced register. const TargetRegisterClass *getNewRC() const { return newRC_; } }; - - class SimpleRegisterCoalescing : public MachineFunctionPass, - public RegisterCoalescer { - 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; - - public: - static char ID; // Pass identifcation, replacement for typeid - SimpleRegisterCoalescing() : MachineFunctionPass(ID) { - initializeSimpleRegisterCoalescingPass(*PassRegistry::getPassRegistry()); - } - - virtual void getAnalysisUsage(AnalysisUsage &AU) const; - virtual void releaseMemory(); - - /// runOnMachineFunction - pass entry point - virtual bool runOnMachineFunction(MachineFunction&); - - bool coalesceFunction(MachineFunction &mf, RegallocQuery &) { - // This runs as an independent pass, so don't do anything. - return false; - } - - /// print - Implement the dump method. - virtual void print(raw_ostream &O, const Module* = 0) const; - - private: - /// 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); - }; } // End llvm namespace -// Because of the way .a files work, we must force the SimpleRC -// implementation to be pulled in if the RegisterCoalescing header is -// included. Otherwise we run the risk of RegisterCoalescing being -// used, but the default implementation not being linked into the tool -// that uses it. -FORCE_DEFINING_FILE_TO_BE_LINKED(RegisterCoalescer) -FORCE_DEFINING_FILE_TO_BE_LINKED(SimpleRegisterCoalescing) - #endif |