void SelAlloc::Allocate( )
{
int input;
int output;
int input_offset;
int output_offset;
map<int, sRequest>::iterator p;
set<int>::iterator outer_iter;
bool wrapped;
int max_index;
int max_pri;
vector<int> grants(_outputs, -1);
for ( int iter = 0; iter < _iter; ++iter ) {
// Grant phase
for( outer_iter = _out_occ.begin( );
outer_iter != _out_occ.end( ); ++outer_iter ) {
output = *outer_iter;
// Skip loop if there are no requests
// or the output is already matched or
// the output is masked
if ( ( _out_req[output].empty( ) ) ||
( _outmatch[output] != -1 ) ||
( _outmask[output] != 0 ) ) {
continue;
}
// A round-robin arbiter between input requests
input_offset = _gptrs[output];
p = _out_req[output].begin( );
while( ( p != _out_req[output].end( ) ) &&
( p->second.port < input_offset ) ) {
p++;
}
max_index = -1;
max_pri = 0;
wrapped = false;
while( (!wrapped) ||
( ( p != _out_req[output].end() ) &&
( p->second.port < input_offset ) ) ) {
if ( p == _out_req[output].end( ) ) {
if ( wrapped ) { break; }
// p is valid here because empty lists
// are skipped (above)
p = _out_req[output].begin( );
wrapped = true;
}
input = p->second.port;
// we know the output is free (above) and
// if the input is free, check if request is the
// highest priority so far
if ( ( _inmatch[input] == -1 ) &&
( ( p->second.out_pri > max_pri ) || ( max_index == -1 ) ) ) {
max_pri = p->second.out_pri;
max_index = input;
}
p++;
}
if ( max_index != -1 ) { // grant
grants[output] = max_index;
}
}
#ifdef DEBUG_SELALLOC
cout << "grants: ";
for ( int i = 0; i < _outputs; ++i ) {
cout << grants[i] << " ";
}
cout << endl;
cout << "aptrs: ";
for ( int i = 0; i < _inputs; ++i ) {
cout << _aptrs[i] << " ";
}
cout << endl;
#endif
// Accept phase
for ( outer_iter = _in_occ.begin( );
outer_iter != _in_occ.end( ); ++outer_iter ) {
input = *outer_iter;
if ( _in_req[input].empty( ) ) {
continue;
}
// A round-robin arbiter between output grants
output_offset = _aptrs[input];
p = _in_req[input].begin( );
while( ( p != _in_req[input].end( ) ) &&
( p->second.port < output_offset ) ) {
p++;
}
max_index = -1;
max_pri = 0;
wrapped = false;
while( (!wrapped) ||
( ( p != _in_req[input].end() ) &&
( p->second.port < output_offset ) ) ) {
if ( p == _in_req[input].end( ) ) {
if ( wrapped ) { break; }
// p is valid here because empty lists
// are skipped (above)
p = _in_req[input].begin( );
wrapped = true;
}
output = p->second.port;
// we know the output is free (above) and
// if the input is free, check if the highest
// priroity
if ( ( grants[output] == input ) &&
( !_out_req[output].empty( ) ) &&
( ( p->second.in_pri > max_pri ) || ( max_index == -1 ) ) ) {
max_pri = p->second.in_pri;
max_index = output;
}
p++;
}
if ( max_index != -1 ) {
// Accept
output = max_index;
_inmatch[input] = output;
_outmatch[output] = input;
// Only update pointers if accepted during the 1st iteration
if ( iter == 0 ) {
_gptrs[output] = ( input + 1 ) % _inputs;
_aptrs[input] = ( output + 1 ) % _outputs;
}
}
}
}
#ifdef DEBUG_SELALLOC
cout << "input match: ";
for ( int i = 0; i < _inputs; ++i ) {
cout << _inmatch[i] << " ";
}
cout << endl;
cout << "output match: ";
for ( int j = 0; j < _outputs; ++j ) {
cout << _outmatch[j] << " ";
}
cout << endl;
#endif
}
void iSLIP_Sparse::Allocate( )
{
int input;
int output;
int input_offset;
int output_offset;
map<int, sRequest>::iterator p;
bool wrapped;
for ( int iter = 0; iter < _iSLIP_iter; ++iter )
{
// Grant phase
vector<int> grants(_outputs, -1);
for ( output = 0; output < _outputs; ++output )
{
// Skip loop if there are no requests
// or the output is already matched
if ( ( _out_req[output].empty( ) ) ||
( _outmatch[output] != -1 ) )
{
continue;
}
// A round-robin arbiter between input requests
input_offset = _gptrs[output];
p = _out_req[output].begin( );
while( ( p != _out_req[output].end( ) ) &&
( p->second.port < input_offset ) )
{
p++;
}
wrapped = false;
while( (!wrapped) ||
( ( p != _out_req[output].end( ) ) &&
( p->second.port < input_offset ) ) )
{
if ( p == _out_req[output].end( ) )
{
if ( wrapped )
{
break;
}
// p is valid here because empty lists
// are skipped (above)
p = _out_req[output].begin( );
wrapped = true;
}
input = p->second.port;
// we know the output is free (above) and
// if the input is free, grant request
if ( _inmatch[input] == -1 )
{
grants[output] = input;
break;
}
p++;
}
}
#ifdef DEBUG_ISLIP
cout << "grants: ";
for ( int i = 0; i < _outputs; ++i )
{
cout << grants[i] << " ";
}
cout << endl;
cout << "aptrs: ";
for ( int i = 0; i < _inputs; ++i )
{
cout << _aptrs[i] << " ";
}
cout << endl;
#endif
// Accept phase
for ( input = 0; input < _inputs; ++input )
{
if ( _in_req[input].empty( ) )
{
continue;
}
// A round-robin arbiter between output grants
output_offset = _aptrs[input];
p = _in_req[input].begin( );
while( ( p != _in_req[input].end( ) ) &&
( p->second.port < output_offset ) )
{
p++;
}
wrapped = false;
while( (!wrapped) ||
( ( p != _in_req[input].end( ) ) &&
( p->second.port < output_offset ) ) )
{
if ( p == _in_req[input].end( ) )
{
if ( wrapped )
{
break;
}
// p is valid here because empty lists
// are skipped (above)
p = _in_req[input].begin( );
wrapped = true;
}
output = p->second.port;
// we know the output is free (above) and
// if the input is free, grant request
if ( grants[output] == input )
{
// Accept
_inmatch[input] = output;
_outmatch[output] = input;
// Only update pointers if accepted during the 1st iteration
if ( iter == 0 )
{
_gptrs[output] = ( input + 1 ) % _inputs;
_aptrs[input] = ( output + 1 ) % _outputs;
}
break;
}
p++;
}
}
}
#ifdef DEBUG_ISLIP
cout << "input match: ";
for ( int i = 0; i < _inputs; ++i )
{
cout << _inmatch[i] << " ";
}
cout << endl;
cout << "output match: ";
for ( int j = 0; j < _outputs; ++j )
{
cout << _outmatch[j] << " ";
}
cout << endl;
#endif
}
