bool mtac::is_recursive(mtac::Function& function){
for(auto& basic_block : function){
for(auto& quadruple : basic_block->statements){
if(quadruple.op == mtac::Operator::CALL && quadruple.function().mangled_name() == function.definition().mangled_name()){
return true;
}
}
}
return false;
}
bool mtac::loop_unrolling::operator()(mtac::Function& function){
if(function.loops().empty()){
return false;
}
bool optimized = false;
for(auto& loop : function.loops()){
if(loop.has_estimate() && loop.blocks().size() == 1){
auto it = loop.estimate();
if(it > 100){
auto bb = *loop.begin();
//Do not increase too much the size of the body
if(bb->statements.size() < 20){
unsigned int factor = 0;
if((it % 8) == 0){
factor = 8;
} else if((it % 4) == 0){
factor = 4;
} else if((it % 2) == 0){
factor = 2;
}
if(factor == 0){
continue;
}
LOG<Trace>("loops") << "Unroll the loop with a factor " << factor << log::endl;
function.context->global()->stats().inc_counter("loop_unrolled");
optimized = true;
auto& statements = bb->statements;
//The comparison is not necessary here anymore
auto comparison = statements.back();
statements.pop_back();
int limit = statements.size();
//There are perhaps new references to functions
for(auto& statement : statements){
if(statement.op == mtac::Operator::CALL){
program.call_graph.edge(function.definition(), statement.function())->count += (factor - 1);
}
}
//Save enough space for the new statements
statements.reserve(limit * factor + 1);
//Start at 1 because there is already the original body
for(unsigned int i = 1; i < factor; ++i){
for(int j = 0; j < limit; ++j){
statements.push_back(statements[j]);
}
}
//Put the comparison again at the end
statements.push_back(comparison);
}
}
}
}
return optimized;
}