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author | Eddie Hung <eddie@fpgeh.com> | 2019-07-16 08:53:47 -0700 |
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committer | GitHub <noreply@github.com> | 2019-07-16 08:53:47 -0700 |
commit | 5939b5d636f80d4f9345f5b8d0247332d533b68c (patch) | |
tree | 70be983a4d1e8f0bd906faf135ecfacaabcef363 /passes/techmap | |
parent | ba8ccbdea88fe432187e2481a8525cc1c53b4cf4 (diff) | |
parent | fb062c3426e8acb5b3f54dfed7209631208fec81 (diff) | |
download | yosys-5939b5d636f80d4f9345f5b8d0247332d533b68c.tar.gz yosys-5939b5d636f80d4f9345f5b8d0247332d533b68c.tar.bz2 yosys-5939b5d636f80d4f9345f5b8d0247332d533b68c.zip |
Merge pull request #1188 from YosysHQ/eddie/abc9_push_inverters
abc9: push inverters driving box inputs (comb outputs) through $lut soft logic
Diffstat (limited to 'passes/techmap')
-rw-r--r-- | passes/techmap/abc9.cc | 171 |
1 files changed, 127 insertions, 44 deletions
diff --git a/passes/techmap/abc9.cc b/passes/techmap/abc9.cc index 5f448e37a..658bb1225 100644 --- a/passes/techmap/abc9.cc +++ b/passes/techmap/abc9.cc @@ -24,12 +24,13 @@ #if 0 // Based on &flow3 - better QoR but more experimental -#define ABC_COMMAND_LUT "&st; &ps -l; "/*"&sweep -v;"*/" &scorr; " \ - "&st; &if {W}; &save; &st; &syn2; &if {W}; &save; &load; "\ - "&st; &if -g -K 6; &dch -f; &if {W}; &save; &load; "\ - "&st; &if -g -K 6; &synch2; &if {W}; &save; &load" +#define ABC_COMMAND_LUT "&st; &ps -l; &sweep -v; &scorr; " \ + "&st; &if {W}; &save; &st; &syn2; &if {W} -v; &save; &load; "\ + "&st; &if -g -K 6; &dch -f; &if {W} -v; &save; &load; "\ + "&st; &if -g -K 6; &synch2; &if {W} -v; &save; &load; "\ + "&mfs; &ps -l" #else -#define ABC_COMMAND_LUT "&st; &scorr; &sweep; &dc2; &st; &dch -f; &ps -l; &if {W} {D} -v; &mfs; &ps -l" +#define ABC_COMMAND_LUT "&st; &scorr; &sweep; &dc2; &st; &dch -f; &ps; &if {W} {D} -v; &mfs; &ps -l" #endif @@ -53,6 +54,7 @@ #endif #include "frontends/aiger/aigerparse.h" +#include "kernel/utils.h" #ifdef YOSYS_LINK_ABC extern "C" int Abc_RealMain(int argc, char *argv[]); @@ -570,13 +572,23 @@ void abc9_module(RTLIL::Design *design, RTLIL::Module *current_module, std::stri boxes.emplace_back(cell); } + dict<SigBit, pool<IdString>> bit_drivers, bit_users; + TopoSort<IdString, RTLIL::sort_by_id_str> toposort; + dict<RTLIL::Cell*,RTLIL::Cell*> not2drivers; + dict<SigBit, std::vector<RTLIL::Cell*>> bit2sinks; + std::map<std::string, int> cell_stats; for (auto c : mapped_mod->cells()) { + toposort.node(c->name); + RTLIL::Cell *cell = nullptr; if (c->type == "$_NOT_") { - RTLIL::SigBit a_bit = c->getPort("\\A").as_bit(); - RTLIL::SigBit y_bit = c->getPort("\\Y").as_bit(); + RTLIL::SigBit a_bit = c->getPort("\\A"); + RTLIL::SigBit y_bit = c->getPort("\\Y"); + bit_users[a_bit].insert(c->name); + bit_drivers[y_bit].insert(c->name); + if (!a_bit.wire) { c->setPort("\\Y", module->addWire(NEW_ID)); RTLIL::Wire *wire = module->wire(remap_name(y_bit.wire->name)); @@ -584,11 +596,11 @@ void abc9_module(RTLIL::Design *design, RTLIL::Module *current_module, std::stri module->connect(RTLIL::SigBit(wire, y_bit.offset), RTLIL::S1); } else if (!lut_costs.empty() || !lut_file.empty()) { - RTLIL::Cell* driving_lut = nullptr; + RTLIL::Cell* driver_lut = nullptr; // ABC can return NOT gates that drive POs if (!a_bit.wire->port_input) { // If it's not a NOT gate that that comes from a PI directly, - // find the driving LUT and clone that to guarantee that we won't + // find the driver LUT and clone that to guarantee that we won't // increase the max logic depth // (TODO: Optimise by not cloning unless will increase depth) RTLIL::IdString driver_name; @@ -596,50 +608,38 @@ void abc9_module(RTLIL::Design *design, RTLIL::Module *current_module, std::stri driver_name = stringf("%s$lut", a_bit.wire->name.c_str()); else driver_name = stringf("%s[%d]$lut", a_bit.wire->name.c_str(), a_bit.offset); - driving_lut = mapped_mod->cell(driver_name); + driver_lut = mapped_mod->cell(driver_name); } - if (!driving_lut) { - // If a driver couldn't be found (could be from PI, - // or from a box) then implement using a LUT - cell = module->addLut(remap_name(stringf("%s$lut", c->name.c_str())), - RTLIL::SigBit(module->wires_[remap_name(a_bit.wire->name)], a_bit.offset), - RTLIL::SigBit(module->wires_[remap_name(y_bit.wire->name)], y_bit.offset), - 1); - } - else { - auto driver_a = driving_lut->getPort("\\A").chunks(); - for (auto &chunk : driver_a) - chunk.wire = module->wires_[remap_name(chunk.wire->name)]; - RTLIL::Const driver_lut = driving_lut->getParam("\\LUT"); - for (auto &b : driver_lut.bits) { - if (b == RTLIL::State::S0) b = RTLIL::State::S1; - else if (b == RTLIL::State::S1) b = RTLIL::State::S0; - } + if (!driver_lut) { + // If a driver couldn't be found (could be from PI or box CI) + // then implement using a LUT cell = module->addLut(remap_name(stringf("%s$lut", c->name.c_str())), - driver_a, - RTLIL::SigBit(module->wires_[remap_name(y_bit.wire->name)], y_bit.offset), - driver_lut); + RTLIL::SigBit(module->wires_.at(remap_name(a_bit.wire->name)), a_bit.offset), + RTLIL::SigBit(module->wires_.at(remap_name(y_bit.wire->name)), y_bit.offset), + RTLIL::Const::from_string("01")); + bit2sinks[cell->getPort("\\A")].push_back(cell); + cell_stats["$lut"]++; } + else + not2drivers[c] = driver_lut; + continue; } - else { - cell = module->addCell(remap_name(c->name), "$_NOT_"); - cell->setPort("\\A", RTLIL::SigBit(module->wires_[remap_name(a_bit.wire->name)], a_bit.offset)); - cell->setPort("\\Y", RTLIL::SigBit(module->wires_[remap_name(y_bit.wire->name)], y_bit.offset)); - cell_stats[RTLIL::unescape_id(c->type)]++; - } + else + log_abort(); if (cell && markgroups) cell->attributes["\\abcgroup"] = map_autoidx; continue; } cell_stats[RTLIL::unescape_id(c->type)]++; - RTLIL::Cell *existing_cell = nullptr; + RTLIL::Cell *existing_cell = nullptr; if (c->type == "$lut") { - if (GetSize(c->getPort("\\A")) == 1 && c->getParam("\\LUT").as_int() == 2) { - SigSpec my_a = module->wires_[remap_name(c->getPort("\\A").as_wire()->name)]; - SigSpec my_y = module->wires_[remap_name(c->getPort("\\Y").as_wire()->name)]; + if (GetSize(c->getPort("\\A")) == 1 && c->getParam("\\LUT") == RTLIL::Const::from_string("01")) { + SigSpec my_a = module->wires_.at(remap_name(c->getPort("\\A").as_wire()->name)); + SigSpec my_y = module->wires_.at(remap_name(c->getPort("\\Y").as_wire()->name)); module->connect(my_y, my_a); - if (markgroups) c->attributes["\\abcgroup"] = map_autoidx; + if (markgroups) c->attributes["\\abcgroup"] = map_autoidx; + log_abort(); continue; } cell = module->addCell(remap_name(c->name), c->type); @@ -666,10 +666,20 @@ void abc9_module(RTLIL::Design *design, RTLIL::Module *current_module, std::stri continue; //log_assert(c.width == 1); if (c.wire) - c.wire = module->wires_[remap_name(c.wire->name)]; + c.wire = module->wires_.at(remap_name(c.wire->name)); newsig.append(c); } cell->setPort(conn.first, newsig); + + if (cell->input(conn.first)) { + for (auto i : newsig) + bit2sinks[i].push_back(cell); + for (auto i : conn.second) + bit_users[i].insert(c->name); + } + if (cell->output(conn.first)) + for (auto i : conn.second) + bit_drivers[i].insert(c->name); } } @@ -681,14 +691,14 @@ void abc9_module(RTLIL::Design *design, RTLIL::Module *current_module, std::stri if (!conn.first.is_fully_const()) { auto chunks = conn.first.chunks(); for (auto &c : chunks) - c.wire = module->wires_[remap_name(c.wire->name)]; + c.wire = module->wires_.at(remap_name(c.wire->name)); conn.first = std::move(chunks); } if (!conn.second.is_fully_const()) { auto chunks = conn.second.chunks(); for (auto &c : chunks) if (c.wire) - c.wire = module->wires_[remap_name(c.wire->name)]; + c.wire = module->wires_.at(remap_name(c.wire->name)); conn.second = std::move(chunks); } module->connect(conn); @@ -725,6 +735,79 @@ void abc9_module(RTLIL::Design *design, RTLIL::Module *current_module, std::stri } } + for (auto &it : bit_users) + if (bit_drivers.count(it.first)) + for (auto driver_cell : bit_drivers.at(it.first)) + for (auto user_cell : it.second) + toposort.edge(driver_cell, user_cell); + bool no_loops = toposort.sort(); + log_assert(no_loops); + + for (auto ii = toposort.sorted.rbegin(); ii != toposort.sorted.rend(); ii++) { + RTLIL::Cell *not_cell = mapped_mod->cell(*ii); + log_assert(not_cell); + if (not_cell->type != "$_NOT_") + continue; + auto it = not2drivers.find(not_cell); + if (it == not2drivers.end()) + continue; + RTLIL::Cell *driver_lut = it->second; + RTLIL::SigBit a_bit = not_cell->getPort("\\A"); + RTLIL::SigBit y_bit = not_cell->getPort("\\Y"); + RTLIL::Const driver_mask; + + a_bit.wire = module->wires_.at(remap_name(a_bit.wire->name)); + y_bit.wire = module->wires_.at(remap_name(y_bit.wire->name)); + + auto jt = bit2sinks.find(a_bit); + if (jt == bit2sinks.end()) + goto clone_lut; + + for (auto sink_cell : jt->second) + if (sink_cell->type != "$lut") + goto clone_lut; + + // Push downstream LUTs past inverter + for (auto sink_cell : jt->second) { + SigSpec A = sink_cell->getPort("\\A"); + RTLIL::Const mask = sink_cell->getParam("\\LUT"); + int index = 0; + for (; index < GetSize(A); index++) + if (A[index] == a_bit) + break; + log_assert(index < GetSize(A)); + int i = 0; + while (i < GetSize(mask)) { + for (int j = 0; j < (1 << index); j++) + std::swap(mask[i+j], mask[i+j+(1 << index)]); + i += 1 << (index+1); + } + A[index] = y_bit; + sink_cell->setPort("\\A", A); + sink_cell->setParam("\\LUT", mask); + } + + // Since we have rewritten all sinks (which we know + // to be only LUTs) to be after the inverter, we can + // go ahead and clone the LUT with the expectation + // that the original driving LUT will become dangling + // and get cleaned away +clone_lut: + driver_mask = driver_lut->getParam("\\LUT"); + for (auto &b : driver_mask.bits) { + if (b == RTLIL::State::S0) b = RTLIL::State::S1; + else if (b == RTLIL::State::S1) b = RTLIL::State::S0; + } + auto cell = module->addLut(NEW_ID, + driver_lut->getPort("\\A"), + y_bit, + driver_mask); + for (auto &bit : cell->connections_.at("\\A")) { + bit.wire = module->wires_.at(remap_name(bit.wire->name)); + bit2sinks[bit].push_back(cell); + } + } + //log("ABC RESULTS: internal signals: %8d\n", int(signal_list.size()) - in_wires - out_wires); log("ABC RESULTS: input signals: %8d\n", in_wires); log("ABC RESULTS: output signals: %8d\n", out_wires); |