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Add bufnorm pass
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Signed-off-by: Claire Xenia Wolf <[email protected]>
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clairexen committed Sep 27, 2023
1 parent d510a5f commit 5699244
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1 change: 1 addition & 0 deletions passes/techmap/Makefile.inc
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Expand Up @@ -41,6 +41,7 @@ OBJS += passes/techmap/nlutmap.o
OBJS += passes/techmap/shregmap.o
OBJS += passes/techmap/deminout.o
OBJS += passes/techmap/insbuf.o
OBJS += passes/techmap/bufnorm.o
OBJS += passes/techmap/attrmvcp.o
OBJS += passes/techmap/attrmap.o
OBJS += passes/techmap/zinit.o
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180 changes: 180 additions & 0 deletions passes/techmap/bufnorm.cc
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/*
* yosys -- Yosys Open SYnthesis Suite
*
* Copyright (C) 2012 Claire Xenia Wolf <[email protected]>
*
* 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 BufnormPass : public Pass {
BufnormPass() : Pass("bufnorm", "convert design into buffered-normalized form") { }
void help() override
{
log("\n");
log(" bufnorm [options] [selection]\n");
log("\n");
log("Insert buffer cells into the design as needed, to make sure that each wire\n");
log("has exactly one driving cell port, and aliasing wires are buffered using a\n");
log("chain of buffers in canonical order.\n");
log("\n");
}
void execute(std::vector<std::string> args, RTLIL::Design *design) override
{
log_header(design, "Executing BUFNORM pass (convert to buffer-normalized form).\n");

bool connections_mode = false, bits_mode = false;
IdString buf_celltype, buf_inport = ID::A, buf_outport = ID::Y;

size_t argidx;
for (argidx = 1; argidx < args.size(); argidx++)
{
std::string arg = args[argidx];
if (arg == "-conn") {
connections_mode = true;
continue;
}
if (arg == "-bits") {
bits_mode = true;
continue;
}
if (arg == "-buf" && argidx+3 < args.size()) {
buf_celltype = RTLIL::escape_id(args[++argidx]);
buf_inport = RTLIL::escape_id(args[++argidx]);
buf_outport = RTLIL::escape_id(args[++argidx]);
continue;
}
break;
}
extra_args(args, argidx, design);

if (buf_celltype == IdString())
buf_celltype = bits_mode ? ID($_BUF_) : ID($pos);

for (auto module : design->selected_modules())
{
SigMap sigmap(module);
module->new_connections({});

{
vector<Cell*> old_buffers;
for (auto cell : module->cells())
{
if (cell->type == buf_celltype)
{
SigSpec insig = sigmap(cell->getPort(buf_inport));
SigSpec outsig = sigmap(cell->getPort(buf_outport));
for (int i = 0; i < GetSize(insig) && i < GetSize(outsig); i++)
sigmap.add(insig[i], outsig[i]);
old_buffers.push_back(cell);
}
else
{
for (auto &conn : cell->connections())
{
if (!cell->output(conn.first) || conn.second.is_wire())
continue;
SigSpec insig = module->addWire(NEW_ID, GetSize(conn.second));
SigSpec outsig = sigmap(conn.second);
for (int i = 0; i < GetSize(insig) && i < GetSize(outsig); i++)
sigmap.add(insig[i], outsig[i]);
cell->setPort(conn.first, insig);
}
}
}
for (auto cell : old_buffers)
module->remove(cell);
}

dict<SigBit, pool<Wire*>> bit2wires;
dict<SigBit, SigBit> mapped_bits;
pool<Wire*> unmapped_wires;

for (auto wire : module->wires())
{
for (auto key : sigmap(wire))
bit2wires[key].insert(wire);

if (wire->port_input) {
for (auto bit : SigSpec(wire))
mapped_bits[sigmap(bit)] = bit;
} else {
unmapped_wires.insert(wire);
}
}

for (auto cell : module->cells())
{
for (auto &conn : cell->connections())
{
if (!cell->output(conn.first))
continue;

for (auto bit : conn.second)
mapped_bits[sigmap(bit)] = bit;
unmapped_wires.erase(conn.second.as_wire());
}
}

struct {
bool operator()(Wire *a, Wire *b) const {
if (a->port_id != b->port_id)
return a->port_id < b->port_id;
return a->name.str() < b->name.str();
}
} compareWires;

unmapped_wires.sort(compareWires);

for (auto wire : unmapped_wires)
{
SigSpec keysig = sigmap(wire), insig = wire, outsig = wire;
for (int i = 0; i < GetSize(insig); i++)
insig[i] = mapped_bits.at(keysig[i], State::Sx);
for (int i = 0; i < GetSize(outsig); i++)
mapped_bits[keysig[i]] = outsig[i];

if (connections_mode) {
if (bits_mode) {
for (int i = 0; i < GetSize(insig) && i < GetSize(outsig); i++)
module->connect(outsig[i], insig[i]);
} else {
module->connect(outsig, insig);
}
} else {
if (bits_mode) {
for (int i = 0; i < GetSize(insig) && i < GetSize(outsig); i++) {
Cell *c = module->addCell(NEW_ID, buf_celltype);
c->setPort(buf_inport, insig[i]);
c->setPort(buf_outport, outsig[i]);
c->fixup_parameters();
}
} else {
Cell *c = module->addCell(NEW_ID, buf_celltype);
c->setPort(buf_inport, insig);
c->setPort(buf_outport, outsig);
c->fixup_parameters();
}
}
}
}
}
} BufnormPass;

PRIVATE_NAMESPACE_END

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