GlobalValueNumberingPass.hpp

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/* src/vm/jit/compiler2/GlobalValueNumberingPass.hpp - GlobalValueNumberingPass

   Copyright (C) 2013
   CACAOVM - Verein zur Foerderung der freien virtuellen Maschine CACAO

   This file is part of CACAO.

   This program is free software; you can redistribute it and/or
   modify it under the terms of the GNU General Public License as
   published by the Free Software Foundation; either version 2, or (at
   your option) any later version.

   This program is distributed in the hope that it will be useful, but
   WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
   02110-1301, USA.

*/

#ifndef _JIT_COMPILER2_GLOBALVALUENUMBERINGPASS
#define _JIT_COMPILER2_GLOBALVALUENUMBERINGPASS

#include "vm/jit/compiler2/Pass.hpp"
#include "vm/jit/compiler2/MethodC2.hpp"
#include "vm/jit/compiler2/Instruction.hpp"
#include "future/unordered_set.hpp"
#include "future/unordered_map.hpp"

namespace cacao {
namespace jit {
namespace compiler2 {

/**
 * GlobalValueNumberingPass
 *
 * This pass finds and removes redundant computations based on the high-level
 * intermediate representation of the compiler2, i.e., it removes redundant
 * nodes. It therefore uses the global value numbering algorithm in
 * @cite ReisingerBScThesis.
 */
class GlobalValueNumberingPass : public Pass {
private:
    typedef unordered_set<Instruction*> BlockTy;
    typedef std::list<BlockTy*> PartitionTy;
    typedef std::pair<BlockTy*,int> WorkListPairTy;
    typedef std::list<WorkListPairTy*> WorkListTy;
    typedef unordered_map<BlockTy*,std::vector<bool>* > InWorkListTy;
    typedef unordered_map<Instruction*,BlockTy*> Inst2BlockMapTy;
    typedef std::list<Instruction*> InstructionListTy;
    typedef std::vector<InstructionListTy*> OperandIndex2UsersTy;
    typedef unordered_map<Instruction*,OperandIndex2UsersTy*> OperandInverseMapTy;

    /// these types are needed for the creation of the inital blocks
    typedef unordered_map<Instruction::InstID,BlockTy*,hash<int> > OpcodeBlockMapTy;
    typedef unordered_map<int32_t,BlockTy*> IntBlockMapTy;
    typedef unordered_map<int64_t,BlockTy*> LongBlockMapTy;
    typedef unordered_map<float,BlockTy*> FloatBlockMapTy;
    typedef unordered_map<double,BlockTy*> DoubleBlockMapTy;
    typedef unordered_map<BeginInst*,BlockTy*> BBBlockMapTy;

    typedef unordered_set<Instruction*> TouchedInstListTy;
    typedef unordered_map<BlockTy*,TouchedInstListTy*> Block2TouchedInstListMapTy;

    int max_arity;
    PartitionTy partition;
    Inst2BlockMapTy inst2BlockMap;
    Block2TouchedInstListMapTy block2TouchedInstListMap;
    InWorkListTy inWorkList;
    WorkListTy workList;
    OperandInverseMapTy operandInverseMap;

    BlockTy *create_block();
    void init_partition(Method::const_iterator begin,
        Method::const_iterator end);
    void init_worklist_and_touchedblocks();
    void init_operand_inverse(Method::const_iterator begin,
        Method::const_iterator end);

    InstructionListTy *get_users(Instruction *inst, int op_index);
    void add_to_block(BlockTy *block, Instruction *inst);

    void add_to_worklist(BlockTy *block, int operandIndex);
    std::vector<bool> *get_worklist_flags(BlockTy *block);
    void set_in_worklist(BlockTy *block, int index, bool flag);
    bool is_in_worklist(BlockTy *block, int index);
    WorkListPairTy *selectAndDeleteFromWorkList();

    TouchedInstListTy *get_touched_instructions(BlockTy *block);
    BlockTy *get_block(Instruction *inst);

    void split(BlockTy *block, TouchedInstListTy *instructions);

    void print_block(BlockTy *block);
    void print_blocks();
    void print_instructions(TouchedInstListTy *instructions);
    
    static int arity(BlockTy *block);
    static int compute_max_arity(Method::const_iterator begin,
                                Method::const_iterator end);

    void eliminate_redundancies();
    void eliminate_redundancies_in_block(BlockTy *block);
    
    template <typename T1, typename T2>
    BlockTy *get_or_create_block(T1 &map, T2 key) {
        BlockTy *block = map[key];
        if (!block) {
            block = create_block();
            map[key] = block;
        }
        return block;
    }

    void clean_up_operand_inverse();
public:
    static char ID;
    GlobalValueNumberingPass() : Pass() {}
    virtual bool run(JITData &JD);
    virtual PassUsage& get_PassUsage(PassUsage &PU) const;

    // virtual void initialize();   (optional)
    // virtual void finalize();     (optional)
    // virtual bool verify() const; (optional)
};

} // end namespace compiler2
} // end namespace jit
} // end namespace cacao

#endif /* _JIT_COMPILER2_GLOBALVALUENUMBERINGPASS */


/*
 * These are local overrides for various environment variables in Emacs.
 * Please do not remove this and leave it at the end of the file, where
 * Emacs will automagically detect them.
 * ---------------------------------------------------------------------
 * Local variables:
 * mode: c++
 * indent-tabs-mode: t
 * c-basic-offset: 4
 * tab-width: 4
 * End:
 * vim:noexpandtab:sw=4:ts=4:
 */