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/*
* nextpnr -- Next Generation Place and Route
*
* Copyright (C) 2018 Clifford Wolf <clifford@clifford.at>
* Copyright (C) 2018 David Shah <dave@ds0.me>
*
* 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 "pack.h"
#include <algorithm>
#include <unordered_set>
#include "cells.h"
#include "design_utils.h"
#include "log.h"
NEXTPNR_NAMESPACE_BEGIN
// Pack LUTs and LUT-FF pairs
static void pack_lut_lutffs(Design *design)
{
std::unordered_set<IdString> packed_cells;
std::vector<CellInfo *> new_cells;
for (auto cell : design->cells) {
CellInfo *ci = cell.second;
log_info("cell '%s' is of type '%s'\n", ci->name.c_str(),
ci->type.c_str());
if (is_lut(ci)) {
CellInfo *packed = create_ice_cell(design, "ICESTORM_LC",
ci->name.str() + "_LC");
std::copy(ci->attrs.begin(), ci->attrs.end(),
std::inserter(packed->attrs, packed->attrs.begin()));
packed_cells.insert(ci->name);
new_cells.push_back(packed);
log_info("packed cell %s into %s\n", ci->name.c_str(),
packed->name.c_str());
// See if we can pack into a DFF
// TODO: LUT cascade
NetInfo *o = ci->ports.at("O").net;
CellInfo *dff = net_only_drives(o, is_ff, "D", true);
auto lut_bel = ci->attrs.find("BEL");
bool packed_dff = false;
if (dff) {
log_info("found attached dff %s\n", dff->name.c_str());
auto dff_bel = dff->attrs.find("BEL");
if (lut_bel != ci->attrs.end() && dff_bel != dff->attrs.end() &&
lut_bel->second != dff_bel->second) {
// Locations don't match, can't pack
} else {
lut_to_lc(ci, packed, false);
dff_to_lc(dff, packed, false);
design->nets.erase(o->name);
if (dff_bel != dff->attrs.end())
packed->attrs["BEL"] = dff_bel->second;
packed_cells.insert(dff->name);
log_info("packed cell %s into %s\n", dff->name.c_str(),
packed->name.c_str());
packed_dff = true;
}
}
if (!packed_dff) {
lut_to_lc(ci, packed, true);
}
}
}
for (auto pcell : packed_cells) {
design->cells.erase(pcell);
}
for (auto ncell : new_cells) {
design->cells[ncell->name] = ncell;
}
}
// Pack FFs not packed as LUTFFs
static void pack_nonlut_ffs(Design *design)
{
std::unordered_set<IdString> packed_cells;
std::vector<CellInfo *> new_cells;
for (auto cell : design->cells) {
CellInfo *ci = cell.second;
if (is_ff(ci)) {
CellInfo *packed = create_ice_cell(design, "ICESTORM_LC",
ci->name.str() + "_DFFLC");
std::copy(ci->attrs.begin(), ci->attrs.end(),
std::inserter(packed->attrs, packed->attrs.begin()));
log_info("packed cell %s into %s\n", ci->name.c_str(),
packed->name.c_str());
packed_cells.insert(ci->name);
new_cells.push_back(packed);
dff_to_lc(ci, packed, true);
}
}
for (auto pcell : packed_cells) {
design->cells.erase(pcell);
}
for (auto ncell : new_cells) {
design->cells[ncell->name] = ncell;
}
}
// Pack constants (simple implementation)
static void pack_constants(Design *design)
{
CellInfo *gnd_cell = create_ice_cell(design, "ICESTORM_LC", "$PACKER_GND");
gnd_cell->attrs["LUT_INIT"] = "0";
CellInfo *vcc_cell = create_ice_cell(design, "ICESTORM_LC", "$PACKER_VCC");
vcc_cell->attrs["LUT_INIT"] = "1";
for (auto net : design->nets) {
NetInfo *ni = net.second;
if (ni->driver.cell != nullptr && ni->driver.cell->type == "GND") {
ni->driver.cell = gnd_cell;
ni->driver.port = "O";
design->cells[gnd_cell->name] = gnd_cell;
} else if (ni->driver.cell != nullptr &&
ni->driver.cell->type == "VCC") {
ni->driver.cell = vcc_cell;
ni->driver.port = "O";
design->cells[vcc_cell->name] = vcc_cell;
}
}
}
static bool is_nextpnr_iob(CellInfo *cell)
{
return cell->type == "$nextpnr_ibuf" || cell->type == "$nextpnr_obuf" ||
cell->type == "$nextpnr_iobuf";
}
// Pack IO buffers
static void pack_io(Design *design)
{
std::unordered_set<IdString> packed_cells;
std::vector<CellInfo *> new_cells;
for (auto cell : design->cells) {
CellInfo *ci = cell.second;
if (is_nextpnr_iob(ci)) {
CellInfo *sb = nullptr;
if (ci->type == "$nextpnr_ibuf" || ci->type == "$nextpnr_iobuf") {
sb = net_only_drives(ci->ports.at("O").net, is_sb_io,
"PACKAGE_PIN", true, ci);
} else if (ci->type == "$nextpnr_obuf") {
sb = net_only_drives(ci->ports.at("I").net, is_sb_io,
"PACKAGE_PIN", true, ci);
}
if (sb != nullptr) {
// Trivial case, SB_IO used. Just destroy the net and the
// iobuf
log_info("%s feeds SB_IO %s, removing %s %s.\n",
ci->name.c_str(), sb->name.c_str(), ci->type.c_str(),
ci->name.c_str());
NetInfo *net = sb->ports.at("PACKAGE_PIN").net;
if (net != nullptr) {
design->nets.erase(net->name);
sb->ports.at("PACKAGE_PIN").net = nullptr;
}
} else {
// Create a SB_IO buffer
sb = create_ice_cell(design, "SB_IO");
nxio_to_sb(ci, sb);
new_cells.push_back(sb);
}
packed_cells.insert(ci->name);
std::copy(ci->attrs.begin(), ci->attrs.end(),
std::inserter(sb->attrs, sb->attrs.begin()));
}
}
for (auto pcell : packed_cells) {
design->cells.erase(pcell);
}
for (auto ncell : new_cells) {
design->cells[ncell->name] = ncell;
}
}
// Main pack function
void pack_design(Design *design)
{
pack_constants(design);
pack_io(design);
pack_lut_lutffs(design);
pack_nonlut_ffs(design);
}
NEXTPNR_NAMESPACE_END
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