bool
Emitter::needs_excessive_magic(PerlJIT::AST::Op *ast)
{
std::deque<Term *> nodes(1, ast);
while (nodes.size()) {
Term *node = nodes.front();
nodes.pop_front();
if ((node->get_type() == pj_ttype_lexical || node->get_type() == pj_ttype_variabledeclaration) &&
node->get_value_type()->is_opaque())
return true;
if (node->get_type() != pj_ttype_op)
continue;
Op *op = static_cast<Op *>(node);
bool known = Jittable_Ops.find(op->get_op_type()) != Jittable_Ops.end();
if (!known || !op->may_have_explicit_overload())
continue;
std::vector<Term *> kids = node->get_kids();
nodes.insert(nodes.end(), kids.begin(), kids.end());
}
return false;
}
bool
Emitter::is_jittable(PerlJIT::AST::Term *ast)
{
switch (ast->get_type()) {
case pj_ttype_constant:
case pj_ttype_lexical:
case pj_ttype_variabledeclaration:
return true;
case pj_ttype_optree:
return false;
case pj_ttype_statement:
return is_jittable(static_cast<PerlJIT::AST::Statement *>(ast)->kids[0]);
case pj_ttype_statementsequence: {
std::vector<Term *> all = ast->get_kids();
unsigned int jittable = 0;
for (size_t i = 0, max = all.size(); i < max; ++i)
jittable += is_jittable(all[i]);
// TODO arbitrary threshold, it's probably better to look for
// long stretches of JITtable ops
return jittable * 2 >= all.size();
}
case pj_ttype_op: {
Op *op = static_cast<Op *>(ast);
bool known = Jittable_Ops.find(op->get_op_type()) != Jittable_Ops.end();
if (!known)
return false;
if (op->may_have_explicit_overload())
return true;
if (op->op_class() == pj_opc_binop &&
static_cast<Binop *>(op)->is_synthesized_assignment())
return is_jittable(op->kids[1]);
return !needs_excessive_magic(op);
}
default:
return false;
}
}
