virtual bool operator()( Inst *inst ) {
if ( inst->out_reg or not inst->need_a_register() )
return true;
// make a new reg
CppOutReg *out_reg = cc->new_out_reg( inst->type() );
// assign out_reg + constraint propagation ()
Vec<InstAndPort> assigned_ports;
if ( not assign_port_rec( assigned_ports, inst, -1, out_reg ) ) {
std::cerr << "base constraint cannot be fullfilled !\n";
return false;
}
// edges and optionnal constraints
int num_edge = 0; // , num_optionnal_constraint = 0;
while ( true ) {
// there's an edge for propagation ?
if ( num_edge < assigned_ports.size() ) {
InstAndPort port = assigned_ports[ num_edge++ ];
if ( port.is_an_output() ) {
// sort parents by apparition order
struct SortBySchedNum {
bool operator()( const Inst::Parent &a, const Inst::Parent &b ) const {
return a.inst->sched_num < b.inst->sched_num;
}
};
port.inst->update_sched_num();
std::sort( port.inst->par.begin(), port.inst->par.end(), SortBySchedNum() );
// try to propagate the reg through each output edge
CppOutReg *reg = port.inst->out_reg;
for( Inst::Parent &p : port.inst->par ) {
// std::cout << " " << *port.inst << " -> " << *p.inst << std::endl;
for( Inst *inst = port.inst; ; inst = inst->next_sched ) {
// target is reached ?
if ( inst == p.inst ) {
// assign input port, or insert a copy instruction
if ( not assign_port_rec( assigned_ports, p.inst, p.ninp, reg ) )
insert_copy_inst_before( assigned_ports, inst, p );
break;
}
// if there a conflict
if ( not inst->used_reg_ok_for( reg, port.inst ) ) {
// add a copy inst
insert_copy_inst_before( assigned_ports, inst, p );
break;
}
// -> say that here, reg should be the output of port.inst (and nothing else)
inst->add_used_reg( reg, port.inst );
}
}
} else {
CppOutReg *reg = port.inst->inp_reg[ port.ninp() ];
if ( Inst *dst = port.inst->inp[ port.ninp() ].inst ) {
// std::cout << " " << *port.inst << " <- " << *dst << " " << reg << std::endl;
for( Inst *inst = port.inst->prev_sched; ; inst = inst->prev_sched ) {
if ( not inst ) {
PRINT( *port.inst );
PRINT( *dst );
ERROR( "..." );
}
// target is reached ?
if ( inst == dst ) {
Inst *beg_reg = dst;
// assign output port, or insert a copy instruction
if ( not assign_port_rec( assigned_ports, dst, -1, reg ) ) {
insert_copy_inst_after( assigned_ports, dst, port );
beg_reg = dst->next_sched; // reg will be used starting from the copy inst
}
// -> register the use of reg as output of beg_reg
for( Inst *d = beg_reg; d != port.inst; d = d->next_sched )
inst->add_used_reg( reg, beg_reg );
break;
}
// if there is a conflict
if ( not inst->used_reg_ok_for( reg, dst ) ) {
// add a copy inst
insert_copy_inst_after( assigned_ports, inst, port );
// -> register the use of reg as output of beg_reg
for( Inst *c = inst->next_sched, *d = c; d != port.inst; d = d->next_sched )
inst->add_used_reg( reg, c );
break;
}
}
}
}
continue;
}
// constraint that would be good to fullfill
// if ( num_optionnal_constraint < assigned_ports.size() ) {
// InstAndPort port = assigned_ports[ num_optionnal_constraint++ ];
// for( std::pair<const Inst::PortConstraint,int> &c : port.inst->same_out )
// if ( c.second != Inst::COMPULSORY and c.first.src_ninp == port.ninp_constraint() )
// assign_port_rec( assigned_ports, c.first.dst_inst, c.first.dst_ninp, out_reg );
// continue;
// }
// nothing to propagate
break;
}
return true;
}
