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-rw-r--r--passes/techmap/shregmap.cc164
1 files changed, 159 insertions, 5 deletions
diff --git a/passes/techmap/shregmap.cc b/passes/techmap/shregmap.cc
index f20863ba0..a541b33be 100644
--- a/passes/techmap/shregmap.cc
+++ b/passes/techmap/shregmap.cc
@@ -26,7 +26,9 @@ PRIVATE_NAMESPACE_BEGIN
struct ShregmapTech
{
virtual ~ShregmapTech() { }
- virtual bool analyze(vector<int> &taps) = 0;
+ virtual void init(const Module * /*module*/, const SigMap &/*sigmap*/) {}
+ virtual void non_chain_user(const SigBit &/*bit*/, const Cell* /*cell*/, IdString /*port*/) {}
+ virtual bool analyze(vector<int> &taps, const vector<SigBit> &qbits) = 0;
virtual bool fixup(Cell *cell, dict<int, SigBit> &taps) = 0;
};
@@ -54,7 +56,7 @@ struct ShregmapOptions
struct ShregmapTechGreenpak4 : ShregmapTech
{
- bool analyze(vector<int> &taps)
+ bool analyze(vector<int> &taps, const vector<SigBit> &/*qbits*/)
{
if (GetSize(taps) > 2 && taps[0] == 0 && taps[2] < 17) {
taps.clear();
@@ -91,6 +93,145 @@ struct ShregmapTechGreenpak4 : ShregmapTech
}
};
+struct ShregmapTechXilinx7 : ShregmapTech
+{
+ dict<SigBit, std::tuple<Cell*,int,int>> sigbit_to_shiftx_offset;
+ const ShregmapOptions &opts;
+
+ ShregmapTechXilinx7(const ShregmapOptions &opts) : opts(opts) {}
+
+ virtual void init(const Module* module, const SigMap &sigmap) override
+ {
+ for (const auto &i : module->cells_) {
+ auto cell = i.second;
+ if (cell->type == "$shiftx") {
+ if (cell->getParam("\\Y_WIDTH") != 1) continue;
+ int j = 0;
+ for (auto bit : sigmap(cell->getPort("\\A")))
+ sigbit_to_shiftx_offset[bit] = std::make_tuple(cell, j++, 0);
+ log_assert(j == cell->getParam("\\A_WIDTH").as_int());
+ }
+ else if (cell->type == "$mux") {
+ int j = 0;
+ for (auto bit : sigmap(cell->getPort("\\A")))
+ sigbit_to_shiftx_offset[bit] = std::make_tuple(cell, 0, j++);
+ j = 0;
+ for (auto bit : sigmap(cell->getPort("\\B")))
+ sigbit_to_shiftx_offset[bit] = std::make_tuple(cell, 1, j++);
+ }
+ }
+ }
+
+ virtual void non_chain_user(const SigBit &bit, const Cell *cell, IdString port) override
+ {
+ auto it = sigbit_to_shiftx_offset.find(bit);
+ if (it == sigbit_to_shiftx_offset.end())
+ return;
+ if (cell) {
+ if (cell->type == "$shiftx" && port == "\\A")
+ return;
+ if (cell->type == "$mux" && (port == "\\A" || port == "\\B"))
+ return;
+ }
+ sigbit_to_shiftx_offset.erase(it);
+ }
+
+ virtual bool analyze(vector<int> &taps, const vector<SigBit> &qbits) override
+ {
+ if (GetSize(taps) == 1)
+ return taps[0] >= opts.minlen-1 && sigbit_to_shiftx_offset.count(qbits[0]);
+
+ if (taps.back() < opts.minlen-1)
+ return false;
+
+ Cell *shiftx = nullptr;
+ int group = 0;
+ for (int i = 0; i < GetSize(taps); ++i) {
+ auto it = sigbit_to_shiftx_offset.find(qbits[i]);
+ if (it == sigbit_to_shiftx_offset.end())
+ return false;
+
+ // Check taps are sequential
+ if (i != taps[i])
+ return false;
+ // Check taps are not connected to a shift register,
+ // or sequential to the same shift register
+ if (i == 0) {
+ int offset;
+ std::tie(shiftx,offset,group) = it->second;
+ if (offset != i)
+ return false;
+ }
+ else {
+ Cell *shiftx_ = std::get<0>(it->second);
+ if (shiftx_ != shiftx)
+ return false;
+ int offset = std::get<1>(it->second);
+ if (offset != i)
+ return false;
+ int group_ = std::get<2>(it->second);
+ if (group_ != group)
+ return false;
+ }
+ }
+ log_assert(shiftx);
+
+ // Only map if $shiftx exclusively covers the shift register
+ if (shiftx->type == "$shiftx") {
+ if (GetSize(taps) != shiftx->getParam("\\A_WIDTH").as_int())
+ return false;
+ }
+ else if (shiftx->type == "$mux") {
+ if (GetSize(taps) != 2)
+ return false;
+ }
+ else log_abort();
+
+ return true;
+ }
+
+ virtual bool fixup(Cell *cell, dict<int, SigBit> &taps) override
+ {
+ const auto &tap = *taps.begin();
+ auto bit = tap.second;
+
+ auto it = sigbit_to_shiftx_offset.find(bit);
+ log_assert(it != sigbit_to_shiftx_offset.end());
+
+ auto newcell = cell->module->addCell(NEW_ID, "$__XILINX_SHREG_");
+ newcell->set_src_attribute(cell->get_src_attribute());
+ newcell->setParam("\\DEPTH", cell->getParam("\\DEPTH"));
+ newcell->setParam("\\INIT", cell->getParam("\\INIT"));
+ newcell->setParam("\\CLKPOL", cell->getParam("\\CLKPOL"));
+ newcell->setParam("\\ENPOL", cell->getParam("\\ENPOL"));
+
+ newcell->setPort("\\C", cell->getPort("\\C"));
+ newcell->setPort("\\D", cell->getPort("\\D"));
+ if (cell->hasPort("\\E"))
+ newcell->setPort("\\E", cell->getPort("\\E"));
+
+ Cell* shiftx = std::get<0>(it->second);
+ RTLIL::SigSpec l_wire, q_wire;
+ if (shiftx->type == "$shiftx") {
+ l_wire = shiftx->getPort("\\B");
+ q_wire = shiftx->getPort("\\Y");
+ shiftx->setPort("\\Y", cell->module->addWire(NEW_ID));
+ }
+ else if (shiftx->type == "$mux") {
+ l_wire = shiftx->getPort("\\S");
+ q_wire = shiftx->getPort("\\Y");
+ shiftx->setPort("\\Y", cell->module->addWire(NEW_ID));
+ }
+ else log_abort();
+
+ newcell->setPort("\\Q", q_wire);
+ newcell->setPort("\\L", l_wire);
+
+ return false;
+ }
+};
+
+
struct ShregmapWorker
{
Module *module;
@@ -113,8 +254,10 @@ struct ShregmapWorker
for (auto wire : module->wires())
{
if (wire->port_output || wire->get_bool_attribute("\\keep")) {
- for (auto bit : sigmap(wire))
+ for (auto bit : sigmap(wire)) {
sigbit_with_non_chain_users.insert(bit);
+ if (opts.tech) opts.tech->non_chain_user(bit, nullptr, {});
+ }
}
if (wire->attributes.count("\\init")) {
@@ -152,8 +295,10 @@ struct ShregmapWorker
for (auto conn : cell->connections())
if (cell->input(conn.first))
- for (auto bit : sigmap(conn.second))
+ for (auto bit : sigmap(conn.second)) {
sigbit_with_non_chain_users.insert(bit);
+ if (opts.tech) opts.tech->non_chain_user(bit, cell, conn.first);
+ }
}
}
@@ -258,7 +403,7 @@ struct ShregmapWorker
if (taps.empty() || taps.back() < depth-1)
taps.push_back(depth-1);
- if (opts.tech->analyze(taps))
+ if (opts.tech->analyze(taps, qbits))
break;
taps.pop_back();
@@ -377,6 +522,9 @@ struct ShregmapWorker
ShregmapWorker(Module *module, const ShregmapOptions &opts) :
module(module), sigmap(module), opts(opts), dff_count(0), shreg_count(0)
{
+ if (opts.tech)
+ opts.tech->init(module, sigmap);
+
make_sigbit_chain_next_prev();
find_chain_start_cells();
@@ -501,6 +649,12 @@ struct ShregmapPass : public Pass {
clkpol = "pos";
opts.zinit = true;
opts.tech = new ShregmapTechGreenpak4;
+ }
+ else if (tech == "xilinx") {
+ opts.init = true;
+ opts.params = true;
+ enpol = "any_or_none";
+ opts.tech = new ShregmapTechXilinx7(opts);
} else {
argidx--;
break;
generated by cgit v1.2.3 (git 2.25.1) at 2025-01-04 06:26:34 +0000