yosys/passes/cmds/splitcells.cc

268 lines
8.7 KiB
C++

/*
* yosys -- Yosys Open SYnthesis Suite
*
* Copyright (C) 2012 Claire Xenia Wolf <claire@yosyshq.com>
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*
*/
#include "kernel/yosys.h"
#include "kernel/sigtools.h"
USING_YOSYS_NAMESPACE
PRIVATE_NAMESPACE_BEGIN
struct SplitcellsWorker
{
Module *module;
SigMap sigmap;
dict<SigBit, tuple<IdString,IdString,int>> bit_drivers_db;
dict<SigBit, pool<tuple<IdString,IdString,int>>> bit_users_db;
SplitcellsWorker(Module *module) : module(module), sigmap(module)
{
for (auto cell : module->cells()) {
for (auto conn : cell->connections()) {
if (!cell->output(conn.first)) continue;
for (int i = 0; i < GetSize(conn.second); i++) {
SigBit bit(sigmap(conn.second[i]));
bit_drivers_db[bit] = tuple<IdString,IdString,int>(cell->name, conn.first, i);
}
}
}
for (auto cell : module->cells()) {
for (auto conn : cell->connections()) {
if (!cell->input(conn.first)) continue;
for (int i = 0; i < GetSize(conn.second); i++) {
SigBit bit(sigmap(conn.second[i]));
if (!bit_drivers_db.count(bit)) continue;
bit_users_db[bit].insert(tuple<IdString,IdString,int>(cell->name,
conn.first, i-std::get<2>(bit_drivers_db[bit])));
}
}
}
for (auto wire : module->wires()) {
if (!wire->name.isPublic()) continue;
SigSpec sig(sigmap(wire));
for (int i = 0; i < GetSize(sig); i++) {
SigBit bit(sig[i]);
if (!bit_drivers_db.count(bit)) continue;
bit_users_db[bit].insert(tuple<IdString,IdString,int>(wire->name,
IdString(), i-std::get<2>(bit_drivers_db[bit])));
}
}
}
int split(Cell *cell, const std::string &format)
{
if (cell->type.in("$and", "$mux", "$not", "$or", "$pmux", "$xnor", "$xor"))
{
SigSpec outsig = sigmap(cell->getPort(ID::Y));
if (GetSize(outsig) <= 1) return 0;
std::vector<int> slices;
slices.push_back(0);
int width = GetSize(outsig);
width = std::min(width, GetSize(cell->getPort(ID::A)));
if (cell->hasPort(ID::B))
width = std::min(width, GetSize(cell->getPort(ID::B)));
for (int i = 1; i < width; i++) {
auto &last_users = bit_users_db[outsig[slices.back()]];
auto &this_users = bit_users_db[outsig[i]];
if (last_users != this_users) slices.push_back(i);
}
if (GetSize(slices) <= 1) return 0;
slices.push_back(GetSize(outsig));
log("Splitting %s cell %s/%s into %d slices:\n", log_id(cell->type), log_id(module), log_id(cell), GetSize(slices)-1);
for (int i = 1; i < GetSize(slices); i++)
{
int slice_msb = slices[i]-1;
int slice_lsb = slices[i-1];
IdString slice_name = module->uniquify(cell->name.str() + (slice_msb == slice_lsb ?
stringf("%c%d%c", format[0], slice_lsb, format[1]) :
stringf("%c%d%c%d%c", format[0], slice_msb, format[2], slice_lsb, format[1])));
Cell *slice = module->addCell(slice_name, cell);
auto slice_signal = [&](SigSpec old_sig) -> SigSpec {
SigSpec new_sig;
for (int i = 0; i < GetSize(old_sig); i += GetSize(outsig)) {
int offset = i+slice_lsb;
int length = std::min(GetSize(old_sig)-offset, slice_msb-slice_lsb+1);
new_sig.append(old_sig.extract(offset, length));
}
return new_sig;
};
slice->setPort(ID::A, slice_signal(slice->getPort(ID::A)));
if (slice->hasParam(ID::A_WIDTH))
slice->setParam(ID::A_WIDTH, GetSize(slice->getPort(ID::A)));
if (slice->hasPort(ID::B)) {
slice->setPort(ID::B, slice_signal(slice->getPort(ID::B)));
if (slice->hasParam(ID::B_WIDTH))
slice->setParam(ID::B_WIDTH, GetSize(slice->getPort(ID::B)));
}
slice->setPort(ID::Y, slice_signal(slice->getPort(ID::Y)));
if (slice->hasParam(ID::Y_WIDTH))
slice->setParam(ID::Y_WIDTH, GetSize(slice->getPort(ID::Y)));
if (slice->hasParam(ID::WIDTH))
slice->setParam(ID::WIDTH, GetSize(slice->getPort(ID::Y)));
log(" slice %d: %s => %s\n", i, log_id(slice_name), log_signal(slice->getPort(ID::Y)));
}
module->remove(cell);
return GetSize(slices)-1;
}
if (cell->type.in("$ff", "$dff", "$dffe", "$dffsr", "$dffsre", "$adff", "$adffe", "$aldffe",
"$sdff", "$sdffce", "$sdffe", "$dlatch", "$dlatchsr", "$adlatch"))
{
auto splitports = {ID::D, ID::Q, ID::AD, ID::SET, ID::CLR};
auto splitparams = {ID::ARST_VALUE, ID::SRST_VALUE};
SigSpec outsig = sigmap(cell->getPort(ID::Q));
if (GetSize(outsig) <= 1) return 0;
int width = GetSize(outsig);
std::vector<int> slices;
slices.push_back(0);
for (int i = 1; i < width; i++) {
auto &last_users = bit_users_db[outsig[slices.back()]];
auto &this_users = bit_users_db[outsig[i]];
if (last_users != this_users) slices.push_back(i);
}
if (GetSize(slices) <= 1) return 0;
slices.push_back(GetSize(outsig));
log("Splitting %s cell %s/%s into %d slices:\n", log_id(cell->type), log_id(module), log_id(cell), GetSize(slices)-1);
for (int i = 1; i < GetSize(slices); i++)
{
int slice_msb = slices[i]-1;
int slice_lsb = slices[i-1];
IdString slice_name = module->uniquify(cell->name.str() + (slice_msb == slice_lsb ?
stringf("%c%d%c", format[0], slice_lsb, format[1]) :
stringf("%c%d%c%d%c", format[0], slice_msb, format[2], slice_lsb, format[1])));
Cell *slice = module->addCell(slice_name, cell);
for (IdString portname : splitports) {
if (slice->hasPort(portname)) {
SigSpec sig = slice->getPort(portname);
sig = sig.extract(slice_lsb, slice_msb-slice_lsb+1);
slice->setPort(portname, sig);
}
}
for (IdString paramname : splitparams) {
if (slice->hasParam(paramname)) {
Const val = slice->getParam(paramname);
val = val.extract(slice_lsb, slice_msb-slice_lsb+1);
slice->setParam(paramname, val);
}
}
slice->setParam(ID::WIDTH, GetSize(slice->getPort(ID::Q)));
log(" slice %d: %s => %s\n", i, log_id(slice_name), log_signal(slice->getPort(ID::Q)));
}
module->remove(cell);
return GetSize(slices)-1;
}
return 0;
}
};
struct SplitcellsPass : public Pass {
SplitcellsPass() : Pass("splitcells", "split up multi-bit cells") { }
void help() override
{
// |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|
log("\n");
log(" splitcells [options] [selection]\n");
log("\n");
log("This command splits multi-bit cells into smaller chunks, based on usage of the\n");
log("cell output bits.\n");
log("\n");
log("This command operates only in cells such as $or, $and, and $mux, that are easily\n");
log("cut into bit-slices.\n");
log("\n");
log(" -format char1[char2[char3]]\n");
log(" the first char is inserted between the cell name and the bit index, the\n");
log(" second char is appended to the cell name. e.g. -format () creates cell\n");
log(" names like 'mycell(42)'. the 3rd character is the range separation\n");
log(" character when creating multi-bit cells. the default is '[]:'.\n");
log("\n");
}
void execute(std::vector<std::string> args, RTLIL::Design *design) override
{
std::string format;
log_header(design, "Executing SPLITCELLS pass (splitting up multi-bit cells).\n");
size_t argidx;
for (argidx = 1; argidx < args.size(); argidx++)
{
if (args[argidx] == "-format" && argidx+1 < args.size()) {
format = args[++argidx];
continue;
}
break;
}
extra_args(args, argidx, design);
if (GetSize(format) < 1) format += "[";
if (GetSize(format) < 2) format += "]";
if (GetSize(format) < 3) format += ":";
for (auto module : design->selected_modules())
{
int count_split_pre = 0;
int count_split_post = 0;
while (1) {
SplitcellsWorker worker(module);
bool did_something = false;
for (auto cell : module->selected_cells()) {
int n = worker.split(cell, format);
did_something |= (n != 0);
count_split_pre += (n != 0);
count_split_post += n;
}
if (!did_something)
break;
}
if (count_split_pre)
log("Split %d cells in module %s into %d cell slices.\n",
count_split_pre, log_id(module), count_split_post);
}
}
} SplitnetsPass;
PRIVATE_NAMESPACE_END