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abc9: respect (* keep *) on cells

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This commit is contained in:
Eddie Hung 2020-01-13 19:21:11 -08:00
parent 9ec948f396
commit a6d4ea7463
3 changed files with 87 additions and 62 deletions
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132
backends/aiger/xaiger.cc
View file

@ -186,74 +186,76 @@ struct XAigerWriter
dict<IdString,dict<IdString,int>> arrival_cache;
for (auto cell : module->cells()) {
if (cell->type == "$_NOT_")
{
SigBit A = sigmap(cell->getPort("\\A").as_bit());
SigBit Y = sigmap(cell->getPort("\\Y").as_bit());
unused_bits.erase(A);
undriven_bits.erase(Y);
not_map[Y] = A;
continue;
}
if (cell->type == "$_AND_")
{
SigBit A = sigmap(cell->getPort("\\A").as_bit());
SigBit B = sigmap(cell->getPort("\\B").as_bit());
SigBit Y = sigmap(cell->getPort("\\Y").as_bit());
unused_bits.erase(A);
unused_bits.erase(B);
undriven_bits.erase(Y);
and_map[Y] = make_pair(A, B);
continue;
}
if (cell->type == "$__ABC9_FF_" &&
// The presence of an abc9_mergeability attribute indicates
// that we do want to pass this flop to ABC
cell->attributes.count("\\abc9_mergeability"))
{
SigBit D = sigmap(cell->getPort("\\D").as_bit());
SigBit Q = sigmap(cell->getPort("\\Q").as_bit());
unused_bits.erase(D);
undriven_bits.erase(Q);
alias_map[Q] = D;
auto r YS_ATTRIBUTE(unused) = ff_bits.insert(std::make_pair(D, cell));
log_assert(r.second);
continue;
}
RTLIL::Module* inst_module = module->design->module(cell->type);
if (inst_module) {
auto it = cell->attributes.find("\\abc9_box_seq");
if (it != cell->attributes.end()) {
int abc9_box_seq = it->second.as_int();
if (GetSize(box_list) <= abc9_box_seq)
box_list.resize(abc9_box_seq+1);
box_list[abc9_box_seq] = cell;
// Only flop boxes may have arrival times
if (!inst_module->get_bool_attribute("\\abc9_flop"))
continue;
if (!cell->has_keep_attr()) {
if (cell->type == "$_NOT_")
{
SigBit A = sigmap(cell->getPort("\\A").as_bit());
SigBit Y = sigmap(cell->getPort("\\Y").as_bit());
unused_bits.erase(A);
undriven_bits.erase(Y);
not_map[Y] = A;
continue;
}
auto &cell_arrivals = arrival_cache[cell->type];
for (const auto &conn : cell->connections()) {
auto r = cell_arrivals.insert(conn.first);
auto &arrival = r.first->second;
if (r.second) {
auto port_wire = inst_module->wire(conn.first);
if (port_wire->port_output) {
auto it = port_wire->attributes.find("\\abc9_arrival");
if (it != port_wire->attributes.end()) {
if (it->second.flags != 0)
log_error("Attribute 'abc9_arrival' on port '%s' of module '%s' is not an integer.\n", log_id(port_wire), log_id(cell->type));
arrival = it->second.as_int();
if (cell->type == "$_AND_")
{
SigBit A = sigmap(cell->getPort("\\A").as_bit());
SigBit B = sigmap(cell->getPort("\\B").as_bit());
SigBit Y = sigmap(cell->getPort("\\Y").as_bit());
unused_bits.erase(A);
unused_bits.erase(B);
undriven_bits.erase(Y);
and_map[Y] = make_pair(A, B);
continue;
}
if (cell->type == "$__ABC9_FF_" &&
// The presence of an abc9_mergeability attribute indicates
// that we do want to pass this flop to ABC
cell->attributes.count("\\abc9_mergeability"))
{
SigBit D = sigmap(cell->getPort("\\D").as_bit());
SigBit Q = sigmap(cell->getPort("\\Q").as_bit());
unused_bits.erase(D);
undriven_bits.erase(Q);
alias_map[Q] = D;
auto r YS_ATTRIBUTE(unused) = ff_bits.insert(std::make_pair(D, cell));
log_assert(r.second);
continue;
}
if (inst_module) {
auto it = cell->attributes.find("\\abc9_box_seq");
if (it != cell->attributes.end()) {
int abc9_box_seq = it->second.as_int();
if (GetSize(box_list) <= abc9_box_seq)
box_list.resize(abc9_box_seq+1);
box_list[abc9_box_seq] = cell;
// Only flop boxes may have arrival times
if (!inst_module->get_bool_attribute("\\abc9_flop"))
continue;
}
auto &cell_arrivals = arrival_cache[cell->type];
for (const auto &conn : cell->connections()) {
auto r = cell_arrivals.insert(conn.first);
auto &arrival = r.first->second;
if (r.second) {
auto port_wire = inst_module->wire(conn.first);
if (port_wire->port_output) {
auto it = port_wire->attributes.find("\\abc9_arrival");
if (it != port_wire->attributes.end()) {
if (it->second.flags != 0)
log_error("Attribute 'abc9_arrival' on port '%s' of module '%s' is not an integer.\n", log_id(port_wire), log_id(cell->type));
arrival = it->second.as_int();
}
}
}
if (arrival)
for (auto bit : sigmap(conn.second))
arrival_times[bit] = arrival;
}
if (arrival)
for (auto bit : sigmap(conn.second))
arrival_times[bit] = arrival;
}
}
@ -270,6 +272,9 @@ struct XAigerWriter
for (auto b : c.second) {
Wire *w = b.wire;
if (!w) continue;
// Do not add as PO if bit is already a PI
if (input_bits.count(b))
continue;
if (!w->port_output || !cell_known) {
SigBit I = sigmap(b);
if (I != b)
@ -431,6 +436,9 @@ struct XAigerWriter
for (const auto &bit : output_bits) {
ordered_outputs[bit] = aig_o++;
int aig;
// For inout/keep bits only, the output bit
// should be driven by logic, not the PI,
// so temporarily swap that out
if (input_bits.count(bit)) {
auto it = aig_map.find(bit);
int input_aig = it->second;

2
passes/techmap/abc9_ops.cc
View file

@ -489,6 +489,8 @@ void reintegrate(RTLIL::Module *module)
std::vector<Cell*> boxes;
for (auto cell : module->cells().to_vector()) {
if (cell->has_keep_attr())
continue;
if (cell->type.in(ID($_AND_), ID($_NOT_), ID($__ABC9_FF_)))
module->remove(cell);
else if (cell->attributes.erase("\\abc9_box_seq"))

15
tests/techmap/abc9.ys
View file

@ -51,3 +51,18 @@ simplemap
equiv_opt -assert abc9 -lut 4
design -load postopt
select -assert-count 2 t:$lut
design -reset
read_verilog -icells <<EOT
module top(input a, b, output o);
wire w;
(* keep *) $_AND_ gate (.Y(w), .A(a), .B(b));
assign o = ~w;
endmodule
EOT
simplemap
equiv_opt -assert abc9 -lut 4
design -load postopt
select -assert-count 1 t:$lut
select -assert-count 1 t:$_AND_