yosys/passes/techmap/demuxmap.cc

81 lines
2.6 KiB
C++

/*
* yosys -- Yosys Open SYnthesis Suite
*
* Copyright (C) 2022 Marcelina Kościelnicka <mwk@0x04.net>
*
* 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 DemuxmapPass : public Pass {
DemuxmapPass() : Pass("demuxmap", "transform $demux cells to $eq + $mux cells") { }
void help() override
{
// |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|
log("\n");
log(" demuxmap [selection]\n");
log("\n");
log("This pass transforms $demux cells to a bunch of equality comparisons.\n");
log("\n");
}
void execute(std::vector<std::string> args, RTLIL::Design *design) override
{
log_header(design, "Executing DEMUXMAP pass.\n");
size_t argidx;
for (argidx = 1; argidx < args.size(); argidx++) {
break;
}
extra_args(args, argidx, design);
for (auto module : design->selected_modules())
for (auto cell : module->selected_cells())
{
if (cell->type != ID($demux))
continue;
SigSpec sel = cell->getPort(ID::S);
SigSpec data = cell->getPort(ID::A);
SigSpec out = cell->getPort(ID::Y);
int width = GetSize(cell->getPort(ID::A));
for (int i = 0; i < 1 << GetSize(sel); i++) {
if (width == 1 && data == State::S1) {
RTLIL::Cell *eq_cell = module->addEq(NEW_ID, sel, Const(i, GetSize(sel)), out[i]);
eq_cell->add_strpool_attribute(ID::src, cell->get_strpool_attribute(ID::src));
} else {
Wire *eq = module->addWire(NEW_ID);
RTLIL::Cell *eq_cell = module->addEq(NEW_ID, sel, Const(i, GetSize(sel)), eq);
eq_cell->add_strpool_attribute(ID::src, cell->get_strpool_attribute(ID::src));
RTLIL::Cell *mux = module->addMux(NEW_ID,
Const(State::S0, width),
data,
eq,
out.extract(i*width, width));
mux->add_strpool_attribute(ID::src, cell->get_strpool_attribute(ID::src));
}
}
module->remove(cell);
}
}
} DemuxmapPass;
PRIVATE_NAMESPACE_END