yosys/passes/techmap/bwmuxmap.cc

71 lines
2.2 KiB
C++

/*
* yosys -- Yosys Open SYnthesis Suite
*
* Copyright (C) 2022 Jannis Harder <jix@yosyshq.com> <me@jix.one>
*
* 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"
USING_YOSYS_NAMESPACE
PRIVATE_NAMESPACE_BEGIN
struct BwmuxmapPass : public Pass {
BwmuxmapPass() : Pass("bwmuxmap", "replace $bwmux cells with equivalent logic") {}
void help() override
{
// |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|
log("\n");
log(" bwmxumap [options] [selection]\n");
log("\n");
log("This pass replaces $bwmux cells with equivalent logic\n");
log("\n");
}
void execute(std::vector<std::string> args, RTLIL::Design *design) override
{
log_header(design, "Executing BWMUXMAP pass.\n");
size_t argidx;
for (argidx = 1; argidx < args.size(); argidx++) {
// if (args[argidx] == "-arg") {
// continue;
// }
break;
}
extra_args(args, argidx, design);
for (auto module : design->selected_modules())
for (auto cell : module->selected_cells())
{
if (cell->type != ID($bwmux))
continue;
auto &sig_y = cell->getPort(ID::Y);
auto &sig_a = cell->getPort(ID::A);
auto &sig_b = cell->getPort(ID::B);
auto &sig_s = cell->getPort(ID::S);
auto not_s = module->Not(NEW_ID, sig_s);
auto masked_b = module->And(NEW_ID, sig_s, sig_b);
auto masked_a = module->And(NEW_ID, not_s, sig_a);
module->addOr(NEW_ID, masked_a, masked_b, sig_y);
module->remove(cell);
}
}
} BwmuxmapPass;
PRIVATE_NAMESPACE_END