yosys/techlibs/anlogic/anlogic_fixcarry.cc

131 lines
3.9 KiB
C++

/*
* yosys -- Yosys Open SYnthesis Suite
*
* Copyright (C) 2019 Miodrag Milanovic <miodrag@symbioticeda.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
static SigBit get_bit_or_zero(const SigSpec &sig)
{
if (GetSize(sig) == 0)
return State::S0;
return sig[0];
}
static void fix_carry_chain(Module *module)
{
SigMap sigmap(module);
pool<SigBit> ci_bits;
dict<SigBit, SigBit> mapping_bits;
for (auto cell : module->cells())
{
if (cell->type == ID(AL_MAP_ADDER)) {
if (cell->getParam(ID(ALUTYPE)) != Const("ADD")) continue;
SigBit bit_i0 = get_bit_or_zero(cell->getPort(ID(a)));
SigBit bit_i1 = get_bit_or_zero(cell->getPort(ID(b)));
if (bit_i0 == State::S0 && bit_i1== State::S0) {
SigBit bit_ci = get_bit_or_zero(cell->getPort(ID(c)));
SigSpec o = cell->getPort(ID(o));
if (GetSize(o) == 2) {
SigBit bit_o = o[0];
ci_bits.insert(bit_ci);
mapping_bits[bit_ci] = bit_o;
}
}
}
}
vector<Cell*> adders_to_fix_cells;
for (auto cell : module->cells())
{
if (cell->type == ID(AL_MAP_ADDER)) {
if (cell->getParam(ID(ALUTYPE)) != Const("ADD")) continue;
SigBit bit_ci = get_bit_or_zero(cell->getPort(ID(c)));
SigBit bit_i0 = get_bit_or_zero(cell->getPort(ID(a)));
SigBit bit_i1 = get_bit_or_zero(cell->getPort(ID(b)));
SigBit canonical_bit = sigmap(bit_ci);
if (!ci_bits.count(canonical_bit))
continue;
if (bit_i0 == State::S0 && bit_i1== State::S0)
continue;
adders_to_fix_cells.push_back(cell);
log("Found %s cell named %s with invalid 'c' signal.\n", log_id(cell->type), log_id(cell));
}
}
for (auto cell : adders_to_fix_cells)
{
SigBit bit_ci = get_bit_or_zero(cell->getPort(ID(c)));
SigBit canonical_bit = sigmap(bit_ci);
auto bit = mapping_bits.at(canonical_bit);
log("Fixing %s cell named %s breaking carry chain.\n", log_id(cell->type), log_id(cell));
Cell *c = module->addCell(NEW_ID, ID(AL_MAP_ADDER));
SigBit new_bit = module->addWire(NEW_ID);
SigBit dummy_bit = module->addWire(NEW_ID);
SigSpec bits;
bits.append(dummy_bit);
bits.append(new_bit);
c->setParam(ID(ALUTYPE), Const("ADD_CARRY"));
c->setPort(ID(a), bit);
c->setPort(ID(b), State::S0);
c->setPort(ID(c), State::S0);
c->setPort(ID(o), bits);
cell->setPort(ID(c), new_bit);
}
}
struct AnlogicCarryFixPass : public Pass {
AnlogicCarryFixPass() : Pass("anlogic_fixcarry", "Anlogic: fix carry chain") { }
void help() YS_OVERRIDE
{
// |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|
log("\n");
log(" anlogic_fixcarry [options] [selection]\n");
log("\n");
log("Add Anlogic adders to fix carry chain if needed.\n");
log("\n");
}
void execute(std::vector<std::string> args, RTLIL::Design *design) YS_OVERRIDE
{
log_header(design, "Executing anlogic_fixcarry pass (fix invalid carry chain).\n");
size_t argidx;
for (argidx = 1; argidx < args.size(); argidx++)
{
break;
}
extra_args(args, argidx, design);
Module *module = design->top_module();
if (module == nullptr)
log_cmd_error("No top module found.\n");
fix_carry_chain(module);
}
} AnlogicCarryFixPass;
PRIVATE_NAMESPACE_END