luke
/
yosys
mirror of https://github.com/YosysHQ/yosys.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

fixup! dfflibmap: refactor

This commit is contained in:
Emil J. Tywoniak 2026-03-03 17:24:34 +01:00
parent dc70d58b76
commit 9a8d8886e1
1 changed files with 18 additions and 20 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

38
passes/techmap/dfflibmap.cc
View File

@ -58,14 +58,8 @@ struct CellMatch {
int num_pins = 0; int num_pins = 0;
bool has_noninv_output = false; bool has_noninv_output = false;
enum ScanResult {
REJECT, // cell has unconnected inputs
NO_OUTPUT, // cell is valid but has no Q/QN output
OK // cell is valid with output found
};
// Scan cell pins to count them, check inputs, and identify Q/QN outputs. // Scan cell pins to count them, check inputs, and identify Q/QN outputs.
ScanResult scan_outputs(const LibertyAst *cell, const LibertyAst *ff, bool cell_next_pol) bool find_outputs(const LibertyAst *cell, const LibertyAst *ff, bool cell_next_pol)
{ {
bool found_output = false; bool found_output = false;
for (auto pin : cell->children) { for (auto pin : cell->children) {
@ -76,7 +70,7 @@ struct CellMatch {
continue; continue;
num_pins++; num_pins++;
if (dir->value == "input" && ports.count(pin->args[0]) == 0) if (dir->value == "input" && ports.count(pin->args[0]) == 0)
return REJECT; return false;
const LibertyAst *func = pin->find("function"); const LibertyAst *func = pin->find("function");
if (dir->value == "output" && func != nullptr) { if (dir->value == "output" && func != nullptr) {
std::string value = func->value; std::string value = func->value;
@ -84,18 +78,20 @@ struct CellMatch {
// next_state negation propagated to output // next_state negation propagated to output
if (value == ff->args[0]) { if (value == ff->args[0]) {
ports[pin->args[0]] = cell_next_pol ? 'Q' : 'q'; ports[pin->args[0]] = cell_next_pol ? 'Q' : 'q';
if (cell_next_pol) has_noninv_output = true; if (cell_next_pol)
has_noninv_output = true;
found_output = true; found_output = true;
} else if (value == ff->args[1]) { } else if (value == ff->args[1]) {
ports[pin->args[0]] = cell_next_pol ? 'q' : 'Q'; ports[pin->args[0]] = cell_next_pol ? 'q' : 'Q';
if (!cell_next_pol) has_noninv_output = true; if (!cell_next_pol)
has_noninv_output = true;
found_output = true; found_output = true;
} }
} }
if (ports.count(pin->args[0]) == 0) if (ports.count(pin->args[0]) == 0)
ports[pin->args[0]] = 0; ports[pin->args[0]] = 0;
} }
return found_output ? OK : NO_OUTPUT; return found_output;
} }
}; };
@ -236,6 +232,7 @@ static bool parse_next_state(const LibertyAst *cell, const LibertyAst *attr, std
return false; return false;
} }
// TODO refactor this enable pin logic
data_not_inverted = true; data_not_inverted = true;
data_name = ""; data_name = "";
enable_not_inverted = true; enable_not_inverted = true;
@ -357,13 +354,14 @@ struct DffFinder {
CellMatch match; CellMatch match;
match.ports[cell_clk_pin] = 'C'; match.ports[cell_clk_pin] = 'C';
if (ff.has_arst) match.ports[cell_rst_pin] = 'R'; if (ff.has_arst)
if (ff.has_ce) match.ports[cell_enable_pin] = 'E'; match.ports[cell_rst_pin] = 'R';
if (ff.has_ce)
match.ports[cell_enable_pin] = 'E';
match.ports[cell_next_pin] = 'D'; match.ports[cell_next_pin] = 'D';
if (match.scan_outputs(cell, cell_ff, cell_next_pol) != CellMatch::OK) if (match.find_outputs(cell, cell_ff, cell_next_pol))
continue; best.update(cell, match);
best.update(cell, match);
} }
best.record_mapping(cell_type); best.record_mapping(cell_type);
} }
@ -404,12 +402,12 @@ struct DffFinder {
match.ports[cell_clk_pin] = 'C'; match.ports[cell_clk_pin] = 'C';
match.ports[cell_set_pin] = 'S'; match.ports[cell_set_pin] = 'S';
match.ports[cell_clr_pin] = 'R'; match.ports[cell_clr_pin] = 'R';
if (ff.has_ce) match.ports[cell_enable_pin] = 'E'; if (ff.has_ce)
match.ports[cell_enable_pin] = 'E';
match.ports[cell_next_pin] = 'D'; match.ports[cell_next_pin] = 'D';
if (match.scan_outputs(cell, cell_ff, cell_next_pol) != CellMatch::OK) if (match.find_outputs(cell, cell_ff, cell_next_pol))
continue; best.update(cell, match);
best.update(cell, match);
} }
best.record_mapping(cell_type); best.record_mapping(cell_type);
} }