forked from OSchip/llvm-project
85 lines
3.2 KiB
C++
85 lines
3.2 KiB
C++
//===-- BranchFolding.h - Fold machine code branch instructions --*- C++ -*===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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#ifndef LLVM_CODEGEN_BRANCHFOLDING_HPP
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#define LLVM_CODEGEN_BRANCHFOLDING_HPP
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#include "llvm/CodeGen/MachineBasicBlock.h"
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#include "llvm/CodeGen/MachineFunctionPass.h"
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#include <vector>
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namespace llvm {
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class MachineFunction;
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class MachineModuleInfo;
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class RegScavenger;
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class TargetInstrInfo;
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class TargetRegisterInfo;
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class BranchFolder {
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public:
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explicit BranchFolder(bool defaultEnableTailMerge);
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bool OptimizeFunction(MachineFunction &MF,
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const TargetInstrInfo *tii,
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const TargetRegisterInfo *tri,
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MachineModuleInfo *mmi);
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private:
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typedef std::pair<unsigned,MachineBasicBlock*> MergePotentialsElt;
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typedef std::vector<MergePotentialsElt>::iterator MPIterator;
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std::vector<MergePotentialsElt> MergePotentials;
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typedef std::pair<MPIterator, MachineBasicBlock::iterator> SameTailElt;
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std::vector<SameTailElt> SameTails;
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bool EnableTailMerge;
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const TargetInstrInfo *TII;
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const TargetRegisterInfo *TRI;
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MachineModuleInfo *MMI;
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RegScavenger *RS;
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bool TailMergeBlocks(MachineFunction &MF);
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bool TryMergeBlocks(MachineBasicBlock* SuccBB,
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MachineBasicBlock* PredBB);
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void ReplaceTailWithBranchTo(MachineBasicBlock::iterator OldInst,
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MachineBasicBlock *NewDest);
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MachineBasicBlock *SplitMBBAt(MachineBasicBlock &CurMBB,
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MachineBasicBlock::iterator BBI1);
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unsigned ComputeSameTails(unsigned CurHash, unsigned minCommonTailLength);
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void RemoveBlocksWithHash(unsigned CurHash, MachineBasicBlock* SuccBB,
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MachineBasicBlock* PredBB);
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unsigned CreateCommonTailOnlyBlock(MachineBasicBlock *&PredBB,
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unsigned maxCommonTailLength);
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bool OptimizeBranches(MachineFunction &MF);
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bool OptimizeBlock(MachineBasicBlock *MBB);
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void RemoveDeadBlock(MachineBasicBlock *MBB);
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bool OptimizeImpDefsBlock(MachineBasicBlock *MBB);
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bool CanFallThrough(MachineBasicBlock *CurBB);
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bool CanFallThrough(MachineBasicBlock *CurBB, bool BranchUnAnalyzable,
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MachineBasicBlock *TBB, MachineBasicBlock *FBB,
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const SmallVectorImpl<MachineOperand> &Cond);
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};
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/// BranchFolderPass - Wrap branch folder in a machine function pass.
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class BranchFolderPass : public MachineFunctionPass,
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public BranchFolder {
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public:
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static char ID;
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explicit BranchFolderPass(bool defaultEnableTailMerge)
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: MachineFunctionPass(&ID), BranchFolder(defaultEnableTailMerge) {}
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virtual bool runOnMachineFunction(MachineFunction &MF);
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virtual const char *getPassName() const { return "Control Flow Optimizer"; }
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};
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}
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#endif /* LLVM_CODEGEN_BRANCHFOLDING_HPP */
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