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Merge 12b443e71c into 5fd39ff3e1

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Emil J 2026-03-20 20:16:12 +13:00 • committed by GitHub
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13 changed files with 452 additions and 68 deletions
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97
frontends/liberty/liberty.cc
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@ -20,6 +20,7 @@
#include "passes/techmap/libparse.h"
#include "kernel/register.h"
#include "kernel/log.h"
#include <array>
YOSYS_NAMESPACE_BEGIN
@ -210,7 +211,10 @@ static void create_ff(RTLIL::Module *module, const LibertyAst *node)
auto [iq_sig, iqn_sig] = find_latch_ff_wires(module, node);
RTLIL::SigSpec clk_sig, data_sig, clear_sig, preset_sig;
bool clk_polarity = true, clear_polarity = true, preset_polarity = true;
const std::string name = RTLIL::unescape_id(module->name);
std::optional<char> clear_preset_var1;
std::optional<char> clear_preset_var2;
for (auto child : node->children) {
if (child->id == "clocked_on")
clk_sig = parse_func_expr(module, child->value.c_str());
@ -220,10 +224,18 @@ static void create_ff(RTLIL::Module *module, const LibertyAst *node)
clear_sig = parse_func_expr(module, child->value.c_str());
if (child->id == "preset")
preset_sig = parse_func_expr(module, child->value.c_str());
for (auto& [id, var] : {pair{"clear_preset_var1", &clear_preset_var1}, {"clear_preset_var2", &clear_preset_var2}})
if (child->id == id) {
if (child->value.size() != 1)
log_error("Unexpected length of clear_preset_var* value %s in FF cell %s\n", child->value, name);
*var = child->value[0];
}
}
if (clk_sig.size() == 0 || data_sig.size() == 0)
log_error("FF cell %s has no next_state and/or clocked_on attribute.\n", RTLIL::unescape_id(module->name));
log_error("FF cell %s has no next_state and/or clocked_on attribute.\n", name);
for (bool rerun_invert_rollback = true; rerun_invert_rollback;)
{
@ -248,36 +260,64 @@ static void create_ff(RTLIL::Module *module, const LibertyAst *node)
}
}
RTLIL::Cell *cell = module->addCell(NEW_ID, ID($_NOT_));
cell->setPort(ID::A, iq_sig);
cell->setPort(ID::Y, iqn_sig);
for (auto& [out_sig, cp_var, neg] : {tuple{iq_sig, clear_preset_var1, false}, {iqn_sig, clear_preset_var2, true}}) {
SigSpec q_sig = out_sig;
if (neg) {
q_sig = module->addWire(NEW_ID, out_sig.as_wire());
module->addNotGate(NEW_ID, q_sig, out_sig);
}
cell = module->addCell(NEW_ID, "");
cell->setPort(ID::D, data_sig);
cell->setPort(ID::Q, iq_sig);
cell->setPort(ID::C, clk_sig);
RTLIL::Cell* cell = module->addCell(NEW_ID, "");
cell->setPort(ID::D, data_sig);
cell->setPort(ID::Q, q_sig);
cell->setPort(ID::C, clk_sig);
if (clear_sig.size() == 0 && preset_sig.size() == 0) {
cell->type = stringf("$_DFF_%c_", clk_polarity ? 'P' : 'N');
if (clear_sig.size() == 0 && preset_sig.size() == 0) {
cell->type = stringf("$_DFF_%c_", clk_polarity ? 'P' : 'N');
}
if (clear_sig.size() == 1 && preset_sig.size() == 0) {
cell->type = stringf("$_DFF_%c%c0_", clk_polarity ? 'P' : 'N', clear_polarity ? 'P' : 'N');
cell->setPort(ID::R, clear_sig);
}
if (clear_sig.size() == 0 && preset_sig.size() == 1) {
cell->type = stringf("$_DFF_%c%c1_", clk_polarity ? 'P' : 'N', preset_polarity ? 'P' : 'N');
cell->setPort(ID::R, preset_sig);
}
if (clear_sig.size() == 1 && preset_sig.size() == 1) {
cell->type = stringf("$_DFFSR_%c%c%c_", clk_polarity ? 'P' : 'N', preset_polarity ? 'P' : 'N', clear_polarity ? 'P' : 'N');
SigBit s_sig = preset_sig;
SigBit r_sig = clear_sig;
if (cp_var && *cp_var != 'X') {
// Either set or reset dominates
bool set_dominates;
if (*cp_var == 'L') {
set_dominates = neg;
} else if (*cp_var == 'H') {
set_dominates = !neg;
} else {
log_error("FF cell %s has unsupported clear&preset behavior \'%c\'.\n", name, *cp_var);
}
log_debug("cell %s variable %d cp_var %c set dominates? %d\n", name, (int)neg + 1, *cp_var, set_dominates);
// S&R priority is well-defined now
if (set_dominates) {
r_sig = module->AndnotGate(NEW_ID, r_sig, s_sig);
} else {
s_sig = module->AndnotGate(NEW_ID, s_sig, r_sig);
}
} else {
log_debug("cell %s variable %d undef c&p behavior\n", name, (int)neg + 1);
}
cell->setPort(ID::S, s_sig);
cell->setPort(ID::R, r_sig);
}
log_assert(!cell->type.empty());
}
if (clear_sig.size() == 1 && preset_sig.size() == 0) {
cell->type = stringf("$_DFF_%c%c0_", clk_polarity ? 'P' : 'N', clear_polarity ? 'P' : 'N');
cell->setPort(ID::R, clear_sig);
}
if (clear_sig.size() == 0 && preset_sig.size() == 1) {
cell->type = stringf("$_DFF_%c%c1_", clk_polarity ? 'P' : 'N', preset_polarity ? 'P' : 'N');
cell->setPort(ID::R, preset_sig);
}
if (clear_sig.size() == 1 && preset_sig.size() == 1) {
cell->type = stringf("$_DFFSR_%c%c%c_", clk_polarity ? 'P' : 'N', preset_polarity ? 'P' : 'N', clear_polarity ? 'P' : 'N');
cell->setPort(ID::S, preset_sig);
cell->setPort(ID::R, clear_sig);
}
log_assert(!cell->type.empty());
}
static bool create_latch(RTLIL::Module *module, const LibertyAst *node, bool flag_ignore_miss_data_latch)
@ -797,3 +837,4 @@ skip_cell:;
YOSYS_NAMESPACE_END