literal_inliner.cc

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#include <lestes/backend_v2/intercode/ge.g.hh>
#include <lestes/backend_v2/structs/func_data.g.hh>
#include <lestes/backend_v2/workers/literal_inliner.g.hh>
#include <lestes/md/literals/literal_info_base.g.hh>
#include <lestes/md/instructions/tm_instr.g.hh>
#include <lestes/std/list.hh>
#include <lestes/std/map.hh>
#include <lestes/std/vector.hh>

package(lestes);
package(backend_v2);
package(workers);

using namespace ::lestes::backend_v2::structs;
using namespace ::lestes::backend_v2::intercode;
using namespace ::lestes::md::instructions;
using namespace ::lestes::md::literals;

typedef list< srp<ge_pi> > ge_pi_list__type;
typedef vector< srp<ge_operand> > ge_op_vector__type;
typedef map< srp<ge_operand_reg>, srp<ge_operand_imm> > reg2imm__type;
typedef set<ulint> id_set__type;

/*!
        \brief Performs immediate inlining.
*/
void literal_inliner::process() {
        
        ptr<reg2imm__type> reg2imm = reg2imm__type::create();
        
        ptr<ge_pi_list__type> body = data_get()->ge_body_get(); 

        for(ge_pi_list__type::iterator it = body->begin(); it!=body->end(); ++it) {
                ptr<ge_pi> ge = *it;
                ptr<tm_instr_base> tm = ge->instruction_get();
                
                if ( !tm ) {
                        continue;
                }
                
                if ( tm->is_load() 
                        && ge->operands_input_get()->front()->kind_get()==ge_operand::IMMEDIATE
                        && ge->operands_output_get()->front()->kind_get()==ge_operand::REGISTER ) {
                                //The instruction is load instruction that loads an immediate to register.
                                (*reg2imm)[ge->operands_output_get()->front().dncast<ge_operand_reg>()] = ge->operands_input_get()->front().dncast<ge_operand_imm>();
                } else if ( tm->versions_get() ) {
                        //The instruction has exchangeable tm_instr version available.
                        //Go through input operands and search for a register operand that can be echanged for its immediate source.
                        ptr<ge_op_vector__type> operands = ge->operands_input_get();
                        for(ge_op_vector__type::iterator it_op = operands->begin(); it_op!=operands->end();) {
                                if ( (*it_op)->kind_get()!=ge_operand::REGISTER ) {
                                        ++it_op;
                                        continue;
                                }
                                
                                ptr<ge_operand_reg> reg = (*it_op).dncast<ge_operand_reg>();
                                
                                reg2imm__type::iterator it_imm = reg2imm->find(reg);
                                
                                if ( it_imm==reg2imm->end() ) {
                                        ++it_op;
                                        continue;
                                }
                                
                                //Ok, the immediate source has been found.
                                ptr<ge_operand_imm> imm = it_imm->second;
                                
                                //Exchange immediate after register.
                                *it_op = imm;
                                
                                //Try to find compatible tm_instr version that is compatible with this operand.
                                if ( find_compatible_version(ge) ) {
                                        //Compatible version exists and it has been set to the ge_pi. 
                                        //Remove dependence on the origin of the register (load of immediate).
                                        ge->dependencies_get()->erase(reg->origin_get());
                                        
                                        //Restart search for exchangeable operans.
                                        it_op = operands->begin();
                                } else {
                                        //Restore operands.
                                        *it_op = reg;
                                        ++it_op;
                                }
                        }
                }
        }
}

/*!
        \brief Finds a target machine instruction description that is compatible with given pseudoinstruction.
        
        \param ge The pseudoinstruction.
*/
bool literal_inliner::find_compatible_version(ptr<ge_pi> ge) {
        ptr<tm_instr_base> backup = ge->instruction_get();
        ptr<id_set__type> versions = backup->versions_get();
        
        for(id_set__type::iterator it = versions->begin(); it!=versions->end();++it) {
                ge->instruction_set(tm_instr::instance(*it));
                
                if ( ge->validate() ) {
                        //Compatible version found.
                        return true;
                }
        }
        
        ge->instruction_set(backup);
        return false;
}

/*!
        \brief Returns data of the currently processed function with immediates inlined whereever possible.
*/
ptr<func_data> literal_inliner::get_result() {
        return data_get();
}



end_package(workers);
end_package(backend_v2);
end_package(lestes);

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