File size: 2,581 Bytes
d1be154 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 | #include <ot/timer/pin.hpp>
#include <ot/timer/arc.hpp>
#include <ot/timer/scc.hpp>
namespace ot {
// Constructor
SCC::SCC(std::vector<Pin*>&& pins) : _pins {std::move(pins)} {
for(auto pin : _pins) {
pin->_scc = this;
}
}
// Function: _is_entry
bool SCC::_is_entry(const Pin& to) const {
assert(to._scc == this);
for(auto arc : to._fanin) {
if(auto& from = arc->_from; from._scc != this) {
return true;
}
}
return false;
}
// Function: _is_exit
bool SCC::_is_exit(const Pin& from) const {
assert(from._scc == this);
for(auto arc : from._fanout) {
if(auto& to = arc->_to; to._scc != this) {
return true;
}
}
return false;
}
// Function: _dump
std::string SCC::_dump() const {
std::ostringstream os;
os << "digraph SCC {\n";
for(auto from : _pins) {
os << " \"" << from->_name << "\";\n";
for(auto& arc : from->_fanout) {
if(from->_scc == arc->_to._scc) {
os << " \""
<< from->_name << "\" -> \"" << arc->_to._name
<< "\";\n";
}
}
}
os << "}\n";
return os.str();
}
// Procedure: _clear
void SCC::_clear() {
// unmark the scc pins and arcs
for(auto pin : _pins) {
for(auto arc : pin->_fanin) {
if(arc->_from._scc == this) {
arc->_remove_state(Arc::LOOP_BREAKER);
}
}
for(auto arc : pin->_fanout) {
if(arc->_to._scc == this) {
arc->_remove_state(Arc::LOOP_BREAKER);
}
}
pin->_scc = nullptr;
}
_pins.clear();
}
// Procedure: _unloop
void SCC::_unloop(Pin& from) {
assert(!from._has_state(Pin::UNLOOP_CAND) && !from._has_state(Pin::IN_UNLOOP_STACK));
from._insert_state(Pin::UNLOOP_CAND | Pin::IN_UNLOOP_STACK);
for(auto arc : from._fanout) {
if(auto& to = arc->_to; to._scc != this) {
continue;
}
else if(!to._has_state(Pin::UNLOOP_CAND)) {
_unloop(to);
}
else if(to._has_state(Pin::IN_UNLOOP_STACK)) {
//OT_LOGD("mark arc ", arc->name(), " as loop breaker");
arc->_insert_state(Arc::LOOP_BREAKER);
}
}
from._remove_state(Pin::IN_UNLOOP_STACK);
}
// Procedure: _unloop
// Find the starting pin to break the loop.
void SCC::_unloop() {
assert(!_pins.empty());
Pin* entry {nullptr};
for(auto pin : _pins) {
if(!_is_entry(*pin)) continue;
if(!entry || pin->is_input()) {
entry = pin;
}
}
if(entry == nullptr) {
entry = _pins[0];
}
_unloop(*entry);
}
}; // end of namespace ot. -----------------------------------------------------------------------
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