nextpnr/machxo2/pack.cc
gatecat 9b51c6e337 clangformat
Signed-off-by: gatecat <gatecat@ds0.me>
2024-09-30 14:51:33 +02:00

1768 lines
78 KiB
C++

/*
* nextpnr -- Next Generation Place and Route
*
* Copyright (C) 2018 gatecat <gatecat@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 <algorithm>
#include <boost/optional.hpp>
#include <iterator>
#include <queue>
#include "cells.h"
#include "chain_utils.h"
#include "design_utils.h"
#include "log.h"
#include "timing.h"
#include "util.h"
NEXTPNR_NAMESPACE_BEGIN
static bool is_nextpnr_iob(Context *ctx, CellInfo *cell)
{
return cell->type == ctx->id("$nextpnr_ibuf") || cell->type == ctx->id("$nextpnr_obuf") ||
cell->type == ctx->id("$nextpnr_iobuf");
}
class MachXO2Packer
{
public:
MachXO2Packer(Context *ctx) : ctx(ctx) {};
private:
// Process the contents of packed_cells and new_cells
void flush_cells()
{
for (auto pcell : packed_cells) {
ctx->cells.erase(pcell);
}
for (auto &ncell : new_cells) {
ctx->cells[ncell->name] = std::move(ncell);
}
packed_cells.clear();
new_cells.clear();
}
// Print logic usage
void print_logic_usage()
{
int total_luts = 0, total_ffs = 0;
int total_ramluts = 0, total_ramwluts = 0;
for (auto bel : ctx->getBels()) {
if (ctx->getBelType(bel) == id_TRELLIS_COMB) {
total_luts += 1;
Loc l = ctx->getBelLocation(bel);
if (l.z <= 3)
total_ramluts += 1;
}
if (ctx->getBelType(bel) == id_TRELLIS_FF)
total_ffs += 1;
if (ctx->getBelType(bel) == id_TRELLIS_RAMW)
total_ramwluts += 2;
}
int used_lgluts = 0, used_cyluts = 0, used_ramluts = 0, used_ramwluts = 0, used_ffs = 0;
for (auto &cell : ctx->cells) {
CellInfo *ci = cell.second.get();
if (is_lut(ctx, ci))
++used_lgluts;
if (is_carry(ctx, ci))
used_cyluts += 2;
if (is_dpram(ctx, ci)) {
used_ramluts += 4;
used_ramwluts += 2;
}
if (is_ff(ctx, ci))
++used_ffs;
}
log_info("Logic utilisation before packing:\n");
auto pc = [](int used, int total) { return 100 * used / total; };
int used_luts = used_lgluts + used_cyluts + used_ramluts + used_ramwluts;
log_info(" Total LUT4s: %5d/%5d %5d%%\n", used_luts, total_luts, pc(used_luts, total_luts));
log_info(" logic LUTs: %5d/%5d %5d%%\n", used_lgluts, total_luts, pc(used_lgluts, total_luts));
log_info(" carry LUTs: %5d/%5d %5d%%\n", used_cyluts, total_luts, pc(used_cyluts, total_luts));
log_info(" RAM LUTs: %5d/%5d %5d%%\n", used_ramluts, total_ramluts, pc(used_ramluts, total_ramluts));
log_info(" RAMW LUTs: %5d/%5d %5d%%\n", used_ramwluts, total_ramwluts,
pc(used_ramwluts, total_ramwluts));
log_break();
log_info(" Total DFFs: %5d/%5d %5d%%\n", used_ffs, total_ffs, pc(used_ffs, total_ffs));
log_break();
}
// Pack LUTs
void pack_luts()
{
log_info("Packing LUTs...\n");
for (auto &cell : ctx->cells) {
CellInfo *ci = cell.second.get();
if (is_lut(ctx, ci))
lut_to_comb(ctx, ci);
}
}
// Gets the z-position of a cell in a macro
int get_macro_cell_z(const CellInfo *ci)
{
if (ci->constr_abs_z)
return ci->constr_z;
else if (ci->cluster != ClusterId() && ctx->getClusterRootCell(ci->cluster) != ci)
return ci->constr_z + get_macro_cell_z(ctx->getClusterRootCell(ci->cluster));
else
return 0;
}
// Gets the relative xy-position of a cell in a macro
std::pair<int, int> get_macro_cell_xy(const CellInfo *ci)
{
if (ci->cluster != ClusterId())
return {ci->constr_x, ci->constr_y};
else
return {0, 0};
}
// Relatively constrain one cell to another
void rel_constr_cells(CellInfo *a, CellInfo *b, int dz)
{
if (a->cluster != ClusterId() && ctx->getClusterRootCell(a->cluster) != a) {
NPNR_ASSERT(b->cluster == ClusterId());
NPNR_ASSERT(b->constr_children.empty());
CellInfo *root = ctx->getClusterRootCell(a->cluster);
root->constr_children.push_back(b);
b->cluster = root->cluster;
b->constr_x = a->constr_x;
b->constr_y = a->constr_y;
b->constr_z = get_macro_cell_z(a) + dz;
b->constr_abs_z = a->constr_abs_z;
} else if (b->cluster != ClusterId() && ctx->getClusterRootCell(b->cluster) != b) {
NPNR_ASSERT(a->constr_children.empty());
CellInfo *root = ctx->getClusterRootCell(b->cluster);
root->constr_children.push_back(a);
a->cluster = root->cluster;
a->constr_x = b->constr_x;
a->constr_y = b->constr_y;
a->constr_z = get_macro_cell_z(b) - dz;
a->constr_abs_z = b->constr_abs_z;
} else if (!b->constr_children.empty()) {
NPNR_ASSERT(a->constr_children.empty());
b->constr_children.push_back(a);
a->cluster = b->cluster;
a->constr_x = 0;
a->constr_y = 0;
a->constr_z = get_macro_cell_z(b) - dz;
a->constr_abs_z = b->constr_abs_z;
} else {
NPNR_ASSERT(a->cluster == ClusterId() || ctx->getClusterRootCell(a->cluster) == a);
a->constr_children.push_back(b);
a->cluster = a->name;
b->cluster = a->name;
b->constr_x = 0;
b->constr_y = 0;
b->constr_z = get_macro_cell_z(a) + dz;
b->constr_abs_z = a->constr_abs_z;
}
}
// Check if it is legal to add a FF to a macro
// This reuses the tile validity code
bool can_add_flipflop_to_macro(CellInfo *comb, CellInfo *ff)
{
Arch::LogicTileStatus lts;
std::fill(lts.cells.begin(), lts.cells.end(), nullptr);
lts.tile_dirty = true;
for (auto &sl : lts.slices)
sl.dirty = true;
auto process_cell = [&](CellInfo *ci) {
if (get_macro_cell_xy(ci) != get_macro_cell_xy(comb))
return;
int z = get_macro_cell_z(ci);
auto &slot = lts.cells.at(z);
NPNR_ASSERT(slot == nullptr);
slot = ci;
// Make sure fields needed for validity checking are set correctly
ctx->assign_arch_info_for_cell(ci);
};
if (comb->cluster != ClusterId()) {
CellInfo *root = ctx->getClusterRootCell(comb->cluster);
process_cell(root);
for (auto &ch : root->constr_children)
process_cell(ch);
} else {
process_cell(comb);
for (auto &ch : comb->constr_children)
process_cell(ch);
}
int ff_z = get_macro_cell_z(comb) + (Arch::BEL_FF - Arch::BEL_COMB);
if (lts.cells.at(ff_z) != nullptr)
return false;
ctx->assign_arch_info_for_cell(ff);
lts.cells.at(ff_z) = ff;
return ctx->slices_compatible(&lts);
}
void pack_ffs()
{
log_info("Packing FFs...\n");
int pairs = 0;
for (auto &cell : ctx->cells) {
CellInfo *ci = cell.second.get();
if (is_ff(ctx, ci)) {
NetInfo *di = ci->getPort(id_DI);
if (di->driver.cell != nullptr && di->driver.cell->type == id_TRELLIS_COMB && di->driver.port == id_F) {
CellInfo *comb = di->driver.cell;
if (comb->cluster != ClusterId()) {
// Special procedure where the comb cell is part of an existing macro
// Need to make sure that CLK, CE, SR, etc are shared correctly, or
// the design will not be routeable
if (can_add_flipflop_to_macro(comb, ci)) {
ci->params[id_SD] = std::string("1");
rel_constr_cells(comb, ci, (Arch::BEL_FF - Arch::BEL_COMB));
// Packed successfully
++pairs;
continue;
}
} else {
// LUT/COMB is not part of a macro, this is the easy case
// Constrain FF and LUT together, no need to rewire
ci->params[id_SD] = std::string("1");
comb->constr_children.push_back(ci);
ci->cluster = comb->name;
comb->cluster = comb->name;
ci->constr_x = 0;
ci->constr_y = 0;
ci->constr_z = (Arch::BEL_FF - Arch::BEL_COMB);
ci->constr_abs_z = false;
// Packed successfully
++pairs;
continue;
}
}
{
// Didn't manage to pack it with a driving combinational cell
// Rewire to use general routing
ci->params[id_SD] = std::string("0");
ci->renamePort(id_DI, id_M);
}
}
}
log_info(" %d FFs paired with LUTs.\n", pairs);
}
// Return true if an port is a top level port that provides its own IOBUF
bool is_top_port(PortRef &port) { return false; }
// Return true if a net only drives a top port
bool drives_top_port(NetInfo *net, PortRef &tp)
{
if (net == nullptr)
return false;
for (auto user : net->users) {
if (is_top_port(user)) {
if (net->users.entries() > 1)
log_error(" port %s.%s must be connected to (and only to) a top level pin\n",
user.cell->name.c_str(ctx), user.port.c_str(ctx));
tp = user;
return true;
}
}
if (net->driver.cell != nullptr && is_top_port(net->driver)) {
if (net->users.entries() > 1)
log_error(" port %s.%s must be connected to (and only to) a top level pin\n",
net->driver.cell->name.c_str(ctx), net->driver.port.c_str(ctx));
tp = net->driver;
return true;
}
return false;
}
// Pass to pack LUT5s into a newly created slice
void pack_lut5xs()
{
log_info("Packing LUT5-7s...\n");
// Gets the "COMB1" side of a LUT5, where we pack a LUT[67] into
auto get_comb1_from_lut5 = [&](CellInfo *lut5) {
NetInfo *f1 = lut5->getPort(id_F1);
NPNR_ASSERT(f1 != nullptr);
NPNR_ASSERT(f1->driver.cell != nullptr);
return f1->driver.cell;
};
dict<IdString, std::pair<CellInfo *, CellInfo *>> lut5_roots, lut6_roots, lut7_roots;
for (auto &cell : ctx->cells) {
CellInfo *ci = cell.second.get();
if (is_pfumx(ctx, ci)) {
NetInfo *f0 = ci->ports.at(id_BLUT).net;
if (f0 == nullptr)
log_error("PFUMX '%s' has disconnected port 'BLUT'\n", ci->name.c_str(ctx));
NetInfo *f1 = ci->ports.at(id_ALUT).net;
if (f1 == nullptr)
log_error("PFUMX '%s' has disconnected port 'ALUT'\n", ci->name.c_str(ctx));
CellInfo *lut0 =
(f0->driver.cell && f0->driver.cell->type == id_TRELLIS_COMB && f0->driver.port == id_F)
? f0->driver.cell
: nullptr;
CellInfo *lut1 =
(f1->driver.cell && f1->driver.cell->type == id_TRELLIS_COMB && f1->driver.port == id_F)
? f1->driver.cell
: nullptr;
if (lut0 == nullptr || lut0->cluster != ClusterId())
log_error("PFUMX '%s' has BLUT driven by cell other than a LUT\n", ci->name.c_str(ctx));
if (lut1 == nullptr || lut1->cluster != ClusterId())
log_error("PFUMX '%s' has ALUT driven by cell other than a LUT\n", ci->name.c_str(ctx));
lut0->addInput(id_F1);
lut0->addInput(id_M);
lut0->addOutput(id_OFX);
ci->movePortTo(id_Z, lut0, id_OFX);
ci->movePortTo(id_ALUT, lut0, id_F1);
ci->movePortTo(id_C0, lut0, id_M);
ci->disconnectPort(id_BLUT);
lut5_roots[lut0->name] = {lut0, lut1};
packed_cells.insert(ci->name);
}
}
flush_cells();
// Pack LUT6s
for (auto &cell : ctx->cells) {
CellInfo *ci = cell.second.get();
if (is_l6mux(ctx, ci)) {
NetInfo *ofx0_0 = ci->ports.at(id_D0).net;
if (ofx0_0 == nullptr)
log_error("L6MUX21 '%s' has disconnected port 'D0'\n", ci->name.c_str(ctx));
NetInfo *ofx0_1 = ci->ports.at(id_D1).net;
if (ofx0_1 == nullptr)
log_error("L6MUX21 '%s' has disconnected port 'D1'\n", ci->name.c_str(ctx));
CellInfo *comb0 = (ofx0_0->driver.cell && ofx0_0->driver.cell->type == id_TRELLIS_COMB &&
ofx0_0->driver.port == id_OFX)
? ofx0_0->driver.cell
: nullptr;
CellInfo *comb1 = (ofx0_1->driver.cell && ofx0_1->driver.cell->type == id_TRELLIS_COMB &&
ofx0_1->driver.port == id_OFX)
? ofx0_1->driver.cell
: nullptr;
if (comb0 == nullptr) {
if (!net_driven_by(ctx, ofx0_0, is_l6mux, id_Z))
log_error("L6MUX21 '%s' has D0 driven by cell other than a SLICE OFX0 but not a LUT7 mux "
"('%s.%s')\n",
ci->name.c_str(ctx), ofx0_0->driver.cell->name.c_str(ctx),
ofx0_0->driver.port.c_str(ctx));
continue;
}
if (lut6_roots.count(comb0->name))
continue;
if (comb1 == nullptr) {
if (!net_driven_by(ctx, ofx0_1, is_l6mux, id_Z))
log_error("L6MUX21 '%s' has D1 driven by cell other than a SLICE OFX0 but not a LUT7 mux "
"('%s.%s')\n",
ci->name.c_str(ctx), ofx0_0->driver.cell->name.c_str(ctx),
ofx0_0->driver.port.c_str(ctx));
continue;
}
if (lut6_roots.count(comb1->name))
continue;
if (ctx->verbose)
log_info(" mux '%s' forms part of a LUT6\n", cell.first.c_str(ctx));
comb0 = get_comb1_from_lut5(comb0);
comb1 = get_comb1_from_lut5(comb1);
comb1->addInput(id_FXA);
comb1->addInput(id_FXB);
comb1->addInput(id_M);
comb1->addOutput(id_OFX);
ci->movePortTo(id_D0, comb1, id_FXA);
ci->movePortTo(id_D1, comb1, id_FXB);
ci->movePortTo(id_SD, comb1, id_M);
ci->movePortTo(id_Z, comb1, id_OFX);
lut6_roots[comb1->name] = {comb0, comb1};
packed_cells.insert(ci->name);
}
}
flush_cells();
// Pack LUT7s
for (auto &cell : ctx->cells) {
CellInfo *ci = cell.second.get();
if (is_l6mux(ctx, ci)) {
NetInfo *ofx1_0 = ci->ports.at(id_D0).net;
if (ofx1_0 == nullptr)
log_error("L6MUX21 '%s' has disconnected port 'D0'\n", ci->name.c_str(ctx));
NetInfo *ofx1_1 = ci->ports.at(id_D1).net;
if (ofx1_1 == nullptr)
log_error("L6MUX21 '%s' has disconnected port 'D1'\n", ci->name.c_str(ctx));
CellInfo *comb1 = (ofx1_0->driver.cell && ofx1_0->driver.cell->type == id_TRELLIS_COMB &&
ofx1_0->driver.port == id_OFX)
? ofx1_0->driver.cell
: nullptr;
CellInfo *comb3 = (ofx1_1->driver.cell && ofx1_1->driver.cell->type == id_TRELLIS_COMB &&
ofx1_1->driver.port == id_OFX)
? ofx1_1->driver.cell
: nullptr;
if (comb1 == nullptr)
log_error("L6MUX21 '%s' has D0 driven by cell other than a SLICE OFX ('%s.%s')\n",
ci->name.c_str(ctx), ofx1_0->driver.cell->name.c_str(ctx),
ofx1_0->driver.port.c_str(ctx));
if (comb3 == nullptr)
log_error("L6MUX21 '%s' has D1 driven by cell other than a SLICE OFX ('%s.%s')\n",
ci->name.c_str(ctx), ofx1_1->driver.cell->name.c_str(ctx),
ofx1_1->driver.port.c_str(ctx));
NetInfo *fxa_0 = comb1->ports.at(id_FXA).net;
if (fxa_0 == nullptr)
log_error("SLICE '%s' has disconnected port 'FXA'\n", comb1->name.c_str(ctx));
NetInfo *fxa_1 = comb3->ports.at(id_FXA).net;
if (fxa_1 == nullptr)
log_error("SLICE '%s' has disconnected port 'FXA'\n", comb3->name.c_str(ctx));
CellInfo *comb2 = net_driven_by(
ctx, fxa_1,
[](const Context *ctx, const CellInfo *ci) {
(void)ctx;
return ci->type == id_TRELLIS_COMB;
},
id_OFX);
if (comb2 == nullptr)
log_error("SLICE '%s' has FXA driven by cell other than a SLICE OFX0 ('%s.%s')\n",
comb3->name.c_str(ctx), fxa_1->driver.cell->name.c_str(ctx),
fxa_1->driver.port.c_str(ctx));
comb2 = get_comb1_from_lut5(comb2);
comb2->addInput(id_FXA);
comb2->addInput(id_FXB);
comb2->addInput(id_M);
comb2->addOutput(id_OFX);
ci->movePortTo(id_D0, comb2, id_FXA);
ci->movePortTo(id_D1, comb2, id_FXB);
ci->movePortTo(id_SD, comb2, id_M);
ci->movePortTo(id_Z, comb2, id_OFX);
lut7_roots[comb2->name] = {comb1, comb3};
packed_cells.insert(ci->name);
}
}
for (auto &root : lut7_roots) {
auto &cells = root.second;
cells.second->cluster = cells.second->name;
cells.second->constr_abs_z = true;
cells.second->constr_z = (1 << Arch::lc_idx_shift) | Arch::BEL_COMB;
rel_constr_cells(cells.second, cells.first, (4 << Arch::lc_idx_shift));
}
for (auto &root : lut6_roots) {
auto &cells = root.second;
rel_constr_cells(cells.second, cells.first, (2 << Arch::lc_idx_shift));
}
for (auto &root : lut5_roots) {
auto &cells = root.second;
rel_constr_cells(cells.first, cells.second, (1 << Arch::lc_idx_shift));
}
flush_cells();
}
// Simple "packer" to remove nextpnr IOBUFs, this assumes IOBUFs are manually instantiated
void pack_io()
{
log_info("Packing IOs..\n");
for (auto &cell : ctx->cells) {
CellInfo *ci = cell.second.get();
if (is_nextpnr_iob(ctx, ci)) {
CellInfo *trio = nullptr;
NetInfo *ionet = nullptr;
PortRef tp;
if (ci->type == ctx->id("$nextpnr_ibuf") || ci->type == ctx->id("$nextpnr_iobuf")) {
ionet = ci->ports.at(id_O).net;
trio = net_only_drives(ctx, ionet, is_trellis_io, id_B, true, ci);
} else if (ci->type == ctx->id("$nextpnr_obuf")) {
ionet = ci->ports.at(id_I).net;
trio = net_only_drives(ctx, ci->ports.at(id_I).net, is_trellis_io, id_B, true, ci);
}
if (bool_or_default(ctx->settings, ctx->id("arch.ooc"))) {
// No IO buffer insertion in out-of-context mode, just remove the nextpnr buffer
// and leave the top level port
for (auto &port : ci->ports)
ci->disconnectPort(port.first);
} else if (trio != nullptr) {
// Trivial case, TRELLIS_IO used. Just remove the IOBUF
log_info("%s feeds TRELLIS_IO %s, removing %s %s.\n", ci->name.c_str(ctx), trio->name.c_str(ctx),
ci->type.c_str(ctx), ci->name.c_str(ctx));
NetInfo *net = trio->ports.at(id_B).net;
if (((ci->type == ctx->id("$nextpnr_ibuf") || ci->type == ctx->id("$nextpnr_iobuf")) &&
net->users.entries() > 1) ||
(ci->type == ctx->id("$nextpnr_obuf") &&
(net->users.entries() > 2 || net->driver.cell != nullptr)) ||
(ci->type == ctx->id("$nextpnr_iobuf") && ci->ports.at(id_I).net != nullptr &&
ci->ports.at(id_I).net->driver.cell != nullptr))
log_error("Pin B of %s '%s' connected to more than a single top level IO.\n",
trio->type.c_str(ctx), trio->name.c_str(ctx));
if (net != nullptr) {
if (net->clkconstr != nullptr && trio->ports.count(id_O)) {
NetInfo *onet = trio->ports.at(id_O).net;
if (onet != nullptr && !onet->clkconstr) {
// Move clock constraint from IO pad to input buffer output
std::swap(net->clkconstr, onet->clkconstr);
}
}
}
} else if (drives_top_port(ionet, tp)) {
log_info("%s feeds %s %s.%s, removing %s %s.\n", ci->name.c_str(ctx), tp.cell->type.c_str(ctx),
tp.cell->name.c_str(ctx), tp.port.c_str(ctx), ci->type.c_str(ctx), ci->name.c_str(ctx));
if (ionet != nullptr) {
ctx->nets.erase(ionet->name);
tp.cell->ports.at(tp.port).net = nullptr;
ci->ports.at(ci->type == ctx->id("$nextpnr_obuf") ? id_I : id_O).net = nullptr;
}
if (ci->type == ctx->id("$nextpnr_iobuf")) {
NetInfo *net2 = ci->ports.at(id_I).net;
if (net2 != nullptr) {
ctx->nets.erase(net2->name);
ci->ports.at(id_I).net = nullptr;
}
}
} else {
// Create a TRELLIS_IO buffer
std::unique_ptr<CellInfo> tr_cell =
create_machxo2_cell(ctx, id_TRELLIS_IO, ci->name.str(ctx) + "$tr_io");
nxio_to_tr(ctx, ci, tr_cell.get(), new_cells, packed_cells);
new_cells.push_back(std::move(tr_cell));
trio = new_cells.back().get();
}
for (auto port : ci->ports)
ci->disconnectPort(port.first);
packed_cells.insert(ci->name);
if (trio != nullptr) {
for (const auto &attr : ci->attrs)
trio->attrs[attr.first] = attr.second;
auto loc_attr = trio->attrs.find(id_LOC);
if (loc_attr != trio->attrs.end()) {
std::string pin = loc_attr->second.as_string();
BelId pinBel = ctx->get_package_pin_bel(pin);
if (pinBel == BelId()) {
log_error("IO pin '%s' constrained to pin '%s', which does not exist for package '%s'.\n",
trio->name.c_str(ctx), pin.c_str(), ctx->package_name);
} else {
log_info("pin '%s' constrained to Bel '%s'.\n", trio->name.c_str(ctx),
ctx->nameOfBel(pinBel));
}
trio->attrs[id_BEL] = ctx->getBelName(pinBel).str(ctx);
}
}
}
}
flush_cells();
}
// Create a feed in to the carry chain
CellInfo *make_carry_feed_in(NetInfo *carry, PortRef chain_in)
{
std::unique_ptr<CellInfo> feedin = create_machxo2_cell(ctx, id_CCU2D);
feedin->params[id_INIT0] = Property(20480, 16);
feedin->params[id_INIT1] = Property(65535, 16);
feedin->params[id_INJECT1_0] = std::string("NO");
feedin->params[id_INJECT1_1] = std::string("YES");
carry->users.remove(chain_in.cell->ports.at(chain_in.port).user_idx);
feedin->connectPort(id_A0, carry);
NetInfo *new_carry = ctx->createNet(ctx->id(feedin->name.str(ctx) + "$COUT"));
feedin->connectPort(id_COUT, new_carry);
chain_in.cell->ports[chain_in.port].net = nullptr;
chain_in.cell->ports[chain_in.port].user_idx = {};
chain_in.cell->connectPort(chain_in.port, new_carry);
CellInfo *feedin_ptr = feedin.get();
IdString feedin_name = feedin->name;
ctx->cells[feedin_name] = std::move(feedin);
return feedin_ptr;
}
// Create a feed out and loop through from the carry chain
CellInfo *make_carry_feed_out(NetInfo *carry, boost::optional<PortRef> chain_next = boost::optional<PortRef>())
{
std::unique_ptr<CellInfo> feedout = create_machxo2_cell(ctx, id_CCU2D);
feedout->params[id_INIT0] = Property(0, 16);
feedout->params[id_INIT1] = Property(20480, 16);
feedout->params[id_INJECT1_0] = std::string("NO");
feedout->params[id_INJECT1_1] = std::string("NO");
PortRef carry_drv = carry->driver;
carry->driver.cell = nullptr;
feedout->connectPort(id_S0, carry);
NetInfo *new_cin = ctx->createNet(ctx->id(feedout->name.str(ctx) + "$CIN"));
new_cin->driver = carry_drv;
carry_drv.cell->ports.at(carry_drv.port).net = new_cin;
feedout->connectPort(id_CIN, new_cin);
if (chain_next) {
// Loop back into LUT4_1 for feedthrough
feedout->connectPort(id_A1, carry);
if (chain_next->cell && chain_next->cell->ports.at(chain_next->port).user_idx)
carry->users.remove(chain_next->cell->ports.at(chain_next->port).user_idx);
NetInfo *new_cout = ctx->createNet(ctx->id(feedout->name.str(ctx) + "$COUT"));
feedout->connectPort(id_COUT, new_cout);
chain_next->cell->ports[chain_next->port].net = nullptr;
chain_next->cell->connectPort(chain_next->port, new_cout);
}
CellInfo *feedout_ptr = feedout.get();
IdString feedout_name = feedout->name;
ctx->cells[feedout_name] = std::move(feedout);
return feedout_ptr;
}
// Split a carry chain into multiple legal chains
std::vector<CellChain> split_carry_chain(CellChain &carryc)
{
bool start_of_chain = true;
std::vector<CellChain> chains;
const int max_length = (ctx->chip_info->width - 4) * 4 - 2;
auto curr_cell = carryc.cells.begin();
while (curr_cell != carryc.cells.end()) {
CellInfo *cell = *curr_cell;
if (start_of_chain) {
chains.emplace_back();
start_of_chain = false;
if (cell->ports.at(id_CIN).net) {
// CIN is not constant and not part of a chain. Must feed in from fabric
PortRef inport;
inport.cell = cell;
inport.port = id_CIN;
CellInfo *feedin = make_carry_feed_in(cell->ports.at(id_CIN).net, inport);
chains.back().cells.push_back(feedin);
}
}
chains.back().cells.push_back(cell);
bool split_chain = int(chains.back().cells.size()) > max_length;
if (split_chain) {
CellInfo *passout = make_carry_feed_out(cell->ports.at(id_COUT).net);
chains.back().cells.back() = passout;
start_of_chain = true;
} else {
NetInfo *carry_net = cell->ports.at(id_COUT).net;
bool at_end = (curr_cell == carryc.cells.end() - 1);
if (carry_net != nullptr && (carry_net->users.entries() > 1 || at_end)) {
boost::optional<PortRef> nextport;
if (!at_end) {
auto next_cell = *(curr_cell + 1);
PortRef nextpr;
nextpr.cell = next_cell;
nextpr.port = id_CIN;
nextport = nextpr;
}
CellInfo *passout = make_carry_feed_out(cell->ports.at(id_COUT).net, nextport);
chains.back().cells.push_back(passout);
}
++curr_cell;
}
}
return chains;
}
// Pack carries and set up appropriate relative constraints
void pack_carries()
{
log_info("Packing carries...\n");
// Find all chains (including single carry cells)
auto carry_chains = find_chains(
ctx, [](const Context *ctx, const CellInfo *cell) { return is_carry(ctx, cell); },
[](const Context *ctx, const CellInfo *cell) {
return net_driven_by(ctx, cell->ports.at(id_CIN).net, is_carry, id_COUT);
},
[](const Context *ctx, const CellInfo *cell) {
return net_only_drives(ctx, cell->ports.at(id_COUT).net, is_carry, id_CIN, false);
},
1);
std::vector<CellChain> all_chains;
// Chain splitting
for (auto &base_chain : carry_chains) {
if (ctx->verbose) {
log_info("Found carry chain: \n");
for (auto entry : base_chain.cells)
log_info(" %s\n", entry->name.c_str(ctx));
log_info("\n");
}
std::vector<CellChain> split_chains = split_carry_chain(base_chain);
for (auto &chain : split_chains) {
all_chains.push_back(chain);
}
}
std::vector<std::vector<CellInfo *>> packed_chains;
// Chain packing
std::vector<std::tuple<CellInfo *, CellInfo *, int>> ff_packing;
for (auto &chain : all_chains) {
int cell_count = 0;
std::vector<CellInfo *> packed_chain;
for (auto &cell : chain.cells) {
std::unique_ptr<CellInfo> comb0 =
create_machxo2_cell(ctx, id_TRELLIS_COMB, cell->name.str(ctx) + "$CCU2_COMB0");
std::unique_ptr<CellInfo> comb1 =
create_machxo2_cell(ctx, id_TRELLIS_COMB, cell->name.str(ctx) + "$CCU2_COMB1");
NetInfo *carry_net = ctx->createNet(ctx->id(cell->name.str(ctx) + "$CCU2_FCI_INT"));
ccu2_to_comb(ctx, cell, comb0.get(), carry_net, 0);
ccu2_to_comb(ctx, cell, comb1.get(), carry_net, 1);
packed_chain.push_back(comb0.get());
packed_chain.push_back(comb1.get());
new_cells.push_back(std::move(comb0));
new_cells.push_back(std::move(comb1));
packed_cells.insert(cell->name);
cell_count++;
}
packed_chains.push_back(packed_chain);
}
// Relative chain placement
for (auto &chain : packed_chains) {
chain.at(0)->constr_abs_z = true;
chain.at(0)->constr_z = 0;
chain.at(0)->cluster = chain.at(0)->name;
for (int i = 1; i < int(chain.size()); i++) {
chain.at(i)->constr_x = (i / 8);
chain.at(i)->constr_y = 0;
chain.at(i)->constr_z = (i % 8) << ctx->lc_idx_shift | Arch::BEL_COMB;
chain.at(i)->constr_abs_z = true;
chain.at(i)->cluster = chain.at(0)->name;
chain.at(0)->constr_children.push_back(chain.at(i));
}
}
flush_cells();
}
// Pack distributed RAM
void pack_dram()
{
for (auto &cell : ctx->cells) {
CellInfo *ci = cell.second.get();
if (is_dpram(ctx, ci)) {
// Create RAMW slice
std::unique_ptr<CellInfo> ramw_slice =
create_machxo2_cell(ctx, id_TRELLIS_RAMW, ci->name.str(ctx) + "$RAMW_SLICE");
dram_to_ramw_split(ctx, ci, ramw_slice.get());
// Create actual RAM slices
std::unique_ptr<CellInfo> ram_comb[4];
for (int i = 0; i < 4; i++) {
ram_comb[i] = create_machxo2_cell(ctx, id_TRELLIS_COMB,
ci->name.str(ctx) + "$DPRAM_COMB" + std::to_string(i));
dram_to_comb(ctx, ci, ram_comb[i].get(), ramw_slice.get(), i);
}
// Create 'block' SLICEs as a placement hint that these cells are mutually exclusive with the RAMW
std::unique_ptr<CellInfo> ramw_block[2];
for (int i = 0; i < 2; i++) {
ramw_block[i] = create_machxo2_cell(ctx, id_TRELLIS_COMB,
ci->name.str(ctx) + "$RAMW_BLOCK" + std::to_string(i));
ramw_block[i]->params[id_MODE] = std::string("RAMW_BLOCK");
}
// Disconnect ports of original cell after packing
ci->disconnectPort(id_WCK);
ci->disconnectPort(id_WRE);
for (int i = 0; i < 4; i++)
ci->disconnectPort(ctx->idf("RAD[%d]", i));
// Setup placement constraints
// Use the 0th bit as an anchor
ram_comb[0]->constr_abs_z = true;
ram_comb[0]->constr_z = Arch::BEL_COMB;
ram_comb[0]->cluster = ram_comb[0]->name;
for (int i = 1; i < 4; i++) {
ram_comb[i]->cluster = ram_comb[0]->name;
ram_comb[i]->constr_abs_z = true;
ram_comb[i]->constr_x = 0;
ram_comb[i]->constr_y = 0;
ram_comb[i]->constr_z = (i << ctx->lc_idx_shift) | Arch::BEL_COMB;
ram_comb[0]->constr_children.push_back(ram_comb[i].get());
}
for (int i = 0; i < 2; i++) {
ramw_block[i]->cluster = ram_comb[0]->name;
ramw_block[i]->constr_abs_z = true;
ramw_block[i]->constr_x = 0;
ramw_block[i]->constr_y = 0;
ramw_block[i]->constr_z = ((i + 4) << ctx->lc_idx_shift) | Arch::BEL_COMB;
ram_comb[0]->constr_children.push_back(ramw_block[i].get());
}
ramw_slice->cluster = ram_comb[0]->name;
ramw_slice->constr_abs_z = true;
ramw_slice->constr_x = 0;
ramw_slice->constr_y = 0;
ramw_slice->constr_z = (4 << ctx->lc_idx_shift) | Arch::BEL_RAMW;
ram_comb[0]->constr_children.push_back(ramw_slice.get());
for (int i = 0; i < 4; i++)
new_cells.push_back(std::move(ram_comb[i]));
for (int i = 0; i < 2; i++)
new_cells.push_back(std::move(ramw_block[i]));
new_cells.push_back(std::move(ramw_slice));
packed_cells.insert(ci->name);
}
}
flush_cells();
}
int make_init_with_const_input(int init, int input, bool value)
{
int new_init = 0;
for (int i = 0; i < 16; i++) {
if (((i >> input) & 0x1) != value) {
int other_i = (i & (~(1 << input))) | (value << input);
if ((init >> other_i) & 0x1)
new_init |= (1 << i);
} else {
if ((init >> i) & 0x1)
new_init |= (1 << i);
}
}
return new_init;
}
void set_lut_input_constant(CellInfo *cell, IdString input, bool value)
{
int index = std::string("ABCD").find(input.str(ctx));
int init = int_or_default(cell->params, id_INIT);
int new_init = make_init_with_const_input(init, index, value);
cell->params[id_INIT] = Property(new_init, 16);
cell->ports.at(input).net = nullptr;
}
void set_ccu2d_input_constant(CellInfo *cell, IdString input, bool value)
{
std::string input_str = input.str(ctx);
int lut = std::stoi(input_str.substr(1));
int index = std::string("ABCD").find(input_str[0]);
int init = int_or_default(cell->params, ctx->id("INIT" + std::to_string(lut)));
int new_init = make_init_with_const_input(init, index, value);
cell->params[ctx->id("INIT" + std::to_string(lut))] = Property(new_init, 16);
cell->ports.at(input).net = nullptr;
}
bool is_ccu2d_port_zero(CellInfo *cell, IdString input)
{
if (!cell->ports.count(input))
return true; // disconnected port is low
if (cell->ports.at(input).net == nullptr || cell->ports.at(input).net->name == ctx->id("$PACKER_GND_NET"))
return true; // disconnected or tied-high low
if (cell->ports.at(input).net->driver.cell != nullptr && cell->ports.at(input).net->driver.cell->type == id_GND)
return true; // pre-pack low
return false;
}
// Merge a net into a constant net
void set_net_constant(const Context *ctx, NetInfo *orig, NetInfo *constnet, bool constval)
{
orig->driver.cell = nullptr;
for (auto user : orig->users) {
if (user.cell != nullptr) {
CellInfo *uc = user.cell;
if (ctx->verbose)
log_info("%s user %s\n", orig->name.c_str(ctx), uc->name.c_str(ctx));
if (is_lut(ctx, uc)) {
set_lut_input_constant(uc, user.port, constval);
} else if (is_ff(ctx, uc) && user.port == id_CE) {
uc->params[id_CEMUX] = std::string(constval ? "1" : "0");
uc->ports[user.port].net = nullptr;
} else if (is_carry(ctx, uc)) {
if (!constval && (user.port.in(id_A0, id_A1, id_B0, id_B1, id_C0, id_C1, id_D0, id_D1))) {
// Input tied low, nothing special to do (bitstream gen will auto-enable tie-low)
uc->ports[user.port].net = nullptr;
} else if (constval) {
if (user.port.in(id_A0, id_A1, id_B0, id_B1)) {
// These inputs can be switched to tie-low without consequence
set_ccu2d_input_constant(uc, user.port, constval);
} else if (user.port == id_C0 && is_ccu2d_port_zero(uc, id_D0)) {
// Partner must be tied low
set_ccu2d_input_constant(uc, user.port, constval);
} else if (user.port == id_D0 && is_ccu2d_port_zero(uc, id_C0)) {
// Partner must be tied low
set_ccu2d_input_constant(uc, user.port, constval);
} else if (user.port == id_C1 && is_ccu2d_port_zero(uc, id_D1)) {
// Partner must be tied low
set_ccu2d_input_constant(uc, user.port, constval);
} else if (user.port == id_D1 && is_ccu2d_port_zero(uc, id_C1)) {
// Partner must be tied low
set_ccu2d_input_constant(uc, user.port, constval);
} else {
// Not allowed to change to a tie-low
uc->ports[user.port].net = constnet;
uc->ports[user.port].user_idx = constnet->users.add(user);
}
} else {
uc->ports[user.port].net = constnet;
uc->ports[user.port].user_idx = constnet->users.add(user);
}
} else if (is_ff(ctx, uc) && user.port == id_LSR &&
((!constval && str_or_default(uc->params, id_LSRMUX, "LSR") == "LSR") ||
(constval && str_or_default(uc->params, id_LSRMUX, "LSR") == "INV"))) {
uc->ports[user.port].net = nullptr;
} else {
uc->ports[user.port].net = constnet;
uc->ports[user.port].user_idx = constnet->users.add(user);
}
}
}
orig->users.clear();
}
// Pack constants (simple implementation)
void pack_constants()
{
log_info("Packing constants..\n");
for (auto &cell : ctx->cells) {
CellInfo *ci = cell.second.get();
if (ci->type.in(ctx->id("VLO"))) {
ci->type = id_GND;
} else if (ci->type.in(ctx->id("VHI"))) {
ci->type = id_VCC;
}
}
std::unique_ptr<CellInfo> gnd_cell = create_machxo2_cell(ctx, id_LUT4, "$PACKER_GND");
gnd_cell->params[id_INIT] = Property(0, 16);
auto gnd_net = std::make_unique<NetInfo>(ctx->id("$PACKER_GND_NET"));
gnd_net->driver.cell = gnd_cell.get();
gnd_net->driver.port = id_Z;
gnd_cell->ports.at(id_Z).net = gnd_net.get();
std::unique_ptr<CellInfo> vcc_cell = create_machxo2_cell(ctx, id_LUT4, "$PACKER_VCC");
vcc_cell->params[id_INIT] = Property(65535, 16);
auto vcc_net = std::make_unique<NetInfo>(ctx->id("$PACKER_VCC_NET"));
vcc_net->driver.cell = vcc_cell.get();
vcc_net->driver.port = id_Z;
vcc_cell->ports.at(id_Z).net = vcc_net.get();
std::vector<IdString> dead_nets;
bool gnd_used = false, vcc_used = false;
for (auto &net : ctx->nets) {
NetInfo *ni = net.second.get();
if (ni->driver.cell != nullptr && ni->driver.cell->type == id_GND) {
IdString drv_cell = ni->driver.cell->name;
set_net_constant(ctx, ni, gnd_net.get(), false);
gnd_used = true;
dead_nets.push_back(net.first);
ctx->cells.erase(drv_cell);
} else if (ni->driver.cell != nullptr && ni->driver.cell->type == id_VCC) {
IdString drv_cell = ni->driver.cell->name;
set_net_constant(ctx, ni, vcc_net.get(), true);
vcc_used = true;
dead_nets.push_back(net.first);
ctx->cells.erase(drv_cell);
}
}
if (gnd_used) {
ctx->cells[gnd_cell->name] = std::move(gnd_cell);
ctx->nets[gnd_net->name] = std::move(gnd_net);
}
if (vcc_used) {
ctx->cells[vcc_cell->name] = std::move(vcc_cell);
ctx->nets[vcc_net->name] = std::move(vcc_net);
}
for (auto dn : dead_nets) {
ctx->nets.erase(dn);
}
}
void autocreate_empty_port(CellInfo *cell, IdString port)
{
if (!cell->ports.count(port)) {
cell->ports[port].name = port;
cell->ports[port].net = nullptr;
cell->ports[port].type = PORT_IN;
}
}
// Pack EBR
void pack_ebr()
{
// Autoincrement WID (starting from 3 seems to match vendor behaviour?)
int wid = 3;
auto rename_bus = [&](CellInfo *c, const std::string &oldname, const std::string &newname, int width,
int oldoffset, int newoffset) {
for (int i = 0; i < width; i++)
c->renamePort(ctx->id(oldname + std::to_string(i + oldoffset)),
ctx->id(newname + std::to_string(i + newoffset)));
};
auto rename_param = [&](CellInfo *c, const std::string &oldname, const std::string &newname) {
IdString o = ctx->id(oldname), n = ctx->id(newname);
if (!c->params.count(o))
return;
c->params[n] = c->params[o];
c->params.erase(o);
};
for (auto &cell : ctx->cells) {
CellInfo *ci = cell.second.get();
// Convert 18-bit PDP RAMs to regular 9-bit DP ones that match the Bel
if (ci->type == id_PDPW8KC) {
ci->params[id_DATA_WIDTH_A] = 18; // force PDP mode
ci->params.erase(id_DATA_WIDTH_W);
rename_bus(ci, "BE", "ADA", 2, 0, 0);
rename_bus(ci, "ADW", "ADA", 9, 0, 4);
rename_bus(ci, "ADR", "ADB", 13, 0, 0);
rename_bus(ci, "CSW", "CSA", 3, 0, 0);
rename_bus(ci, "CSR", "CSB", 3, 0, 0);
rename_bus(ci, "DI", "DIA", 9, 0, 0);
rename_bus(ci, "DI", "DIB", 9, 9, 0);
rename_bus(ci, "DO", "DOA", 9, 9, 0);
rename_bus(ci, "DO", "DOB", 9, 0, 0);
ci->renamePort(id_CLKW, id_CLKA);
ci->renamePort(id_CLKR, id_CLKB);
ci->renamePort(id_CEW, id_CEA);
ci->renamePort(id_CER, id_CEB);
ci->renamePort(id_OCER, id_OCEB);
rename_param(ci, "CLKWMUX", "CLKAMUX");
if (str_or_default(ci->params, id_CLKAMUX) == "CLKW")
ci->params[id_CLKAMUX] = std::string("CLKA");
rename_param(ci, "CLKRMUX", "CLKBMUX");
if (str_or_default(ci->params, id_CLKBMUX) == "CLKR")
ci->params[id_CLKBMUX] = std::string("CLKB");
rename_param(ci, "CSDECODE_W", "CSDECODE_A");
rename_param(ci, "CSDECODE_R", "CSDECODE_B");
std::string outreg = str_or_default(ci->params, id_REGMODE, "NOREG");
ci->params[id_REGMODE_A] = outreg;
ci->params[id_REGMODE_B] = outreg;
ci->params.erase(id_REGMODE);
rename_param(ci, "DATA_WIDTH_R", "DATA_WIDTH_B");
if (ci->ports.count(id_RST)) {
autocreate_empty_port(ci, id_RSTA);
autocreate_empty_port(ci, id_RSTB);
NetInfo *rst = ci->ports.at(id_RST).net;
ci->connectPort(id_RSTA, rst);
ci->connectPort(id_RSTB, rst);
ci->disconnectPort(id_RST);
ci->ports.erase(id_RST);
}
ci->type = id_DP8KC;
}
}
for (auto &cell : ctx->cells) {
CellInfo *ci = cell.second.get();
if (ci->type == id_DP8KC) {
// Add ports, even if disconnected, to ensure correct tie-offs
for (int i = 0; i < 13; i++) {
autocreate_empty_port(ci, ctx->id("ADA" + std::to_string(i)));
autocreate_empty_port(ci, ctx->id("ADB" + std::to_string(i)));
}
for (int i = 0; i < 9; i++) {
autocreate_empty_port(ci, ctx->id("DIA" + std::to_string(i)));
autocreate_empty_port(ci, ctx->id("DIB" + std::to_string(i)));
}
for (int i = 0; i < 3; i++) {
autocreate_empty_port(ci, ctx->id("CSA" + std::to_string(i)));
autocreate_empty_port(ci, ctx->id("CSB" + std::to_string(i)));
}
for (int i = 0; i < 3; i++) {
autocreate_empty_port(ci, ctx->id("CSA" + std::to_string(i)));
autocreate_empty_port(ci, ctx->id("CSB" + std::to_string(i)));
}
autocreate_empty_port(ci, id_CLKA);
autocreate_empty_port(ci, id_CEA);
autocreate_empty_port(ci, id_OCEA);
autocreate_empty_port(ci, id_WEA);
autocreate_empty_port(ci, id_RSTA);
autocreate_empty_port(ci, id_CLKB);
autocreate_empty_port(ci, id_CEB);
autocreate_empty_port(ci, id_OCEB);
autocreate_empty_port(ci, id_WEB);
autocreate_empty_port(ci, id_RSTB);
ci->attrs[id_WID] = wid++;
}
}
}
// Miscellaneous packer tasks
void pack_misc()
{
for (auto &cell : ctx->cells) {
CellInfo *ci = cell.second.get();
if (ci->type.in(id_GSR, id_SGSR)) {
ci->params[id_MODE] = std::string("ACTIVE_LOW");
ci->params[id_SYNCMODE] = ci->type == id_SGSR ? std::string("SYNC") : std::string("ASYNC");
ci->type = id_GSR;
for (BelId bel : ctx->getBels()) {
if (ctx->getBelType(bel) != id_GSR)
continue;
ci->attrs[id_BEL] = ctx->getBelName(bel).str(ctx);
ctx->gsrclk_wire = ctx->getBelPinWire(bel, id_CLK);
}
} else if (ci->type.in(id_TSALL)) {
ci->renamePort(id_TSALL, id_TSALLI);
}
}
}
// Check if two nets have identical constant drivers
bool equal_constant(NetInfo *a, NetInfo *b)
{
if (a == nullptr && b == nullptr)
return true;
if ((a == nullptr) != (b == nullptr))
return false;
if (a->driver.cell == nullptr || b->driver.cell == nullptr)
return (a->driver.cell == nullptr && b->driver.cell == nullptr);
if (a->driver.cell->type != id_GND && a->driver.cell->type != id_VCC)
return false;
return a->driver.cell->type == b->driver.cell->type;
}
struct EdgeClockInfo
{
CellInfo *buffer = nullptr;
NetInfo *unbuf = nullptr;
NetInfo *buf = nullptr;
};
std::map<std::pair<int, int>, EdgeClockInfo> eclks;
std::map<NetInfo *, int> bridge_side_hint;
void tie_zero(CellInfo *ci, IdString port)
{
if (!ci->ports.count(port)) {
ci->ports[port].name = port;
ci->ports[port].type = PORT_IN;
}
IdString name = ctx->id(ci->name.str(ctx) + "$zero$" + port.str(ctx));
auto zero_cell = std::make_unique<CellInfo>(ctx, name, id_GND);
NetInfo *zero_net = ctx->createNet(name);
zero_cell->addOutput(id_GND);
zero_cell->connectPort(id_GND, zero_net);
ci->connectPort(port, zero_net);
new_cells.push_back(std::move(zero_cell));
}
void generate_constraints()
{
log_info("Generating derived timing constraints...\n");
auto MHz = [&](delay_t a) { return 1000.0 / ctx->getDelayNS(a); };
auto equals_epsilon = [](delay_t a, delay_t b) { return (std::abs(a - b) / std::max(double(b), 1.0)) < 1e-3; };
auto equals_epsilon_pair = [&](DelayPair &a, DelayPair &b) {
return equals_epsilon(a.min_delay, b.min_delay) && equals_epsilon(a.max_delay, b.max_delay);
};
auto equals_epsilon_constr = [&](ClockConstraint &a, ClockConstraint &b) {
return equals_epsilon_pair(a.high, b.high) && equals_epsilon_pair(a.low, b.low) &&
equals_epsilon_pair(a.period, b.period);
};
pool<IdString> user_constrained, changed_nets;
for (auto &net : ctx->nets) {
if (net.second->clkconstr != nullptr)
user_constrained.insert(net.first);
changed_nets.insert(net.first);
}
auto get_period = [&](CellInfo *ci, IdString port, delay_t &period) {
if (!ci->ports.count(port))
return false;
NetInfo *from = ci->ports.at(port).net;
if (from == nullptr || from->clkconstr == nullptr)
return false;
period = from->clkconstr->period.minDelay();
return true;
};
auto simple_clk_contraint = [&](delay_t period) {
auto constr = std::unique_ptr<ClockConstraint>(new ClockConstraint());
constr->low = DelayPair(period / 2);
constr->high = DelayPair(period / 2);
constr->period = DelayPair(period);
return constr;
};
auto set_constraint = [&](CellInfo *ci, IdString port, std::unique_ptr<ClockConstraint> constr) {
if (!ci->ports.count(port))
return;
NetInfo *to = ci->ports.at(port).net;
if (to == nullptr)
return;
if (to->clkconstr != nullptr) {
if (!equals_epsilon_constr(*to->clkconstr, *constr) && user_constrained.count(to->name))
log_warning(
" Overriding derived constraint of %.2f MHz on net %s with user-specified constraint of "
"%.2f MHz.\n",
MHz(to->clkconstr->period.min_delay), to->name.c_str(ctx), MHz(constr->period.min_delay));
return;
}
to->clkconstr = std::move(constr);
log_info(" Derived frequency constraint of %.2f MHz for net %s\n", MHz(to->clkconstr->period.minDelay()),
to->name.c_str(ctx));
changed_nets.insert(to->name);
};
auto copy_constraint = [&](CellInfo *ci, IdString fromPort, IdString toPort, double ratio = 1.0) {
if (!ci->ports.count(fromPort) || !ci->ports.count(toPort))
return;
NetInfo *from = ci->ports.at(fromPort).net, *to = ci->ports.at(toPort).net;
if (from == nullptr || from->clkconstr == nullptr || to == nullptr)
return;
if (to->clkconstr != nullptr) {
if (!equals_epsilon(to->clkconstr->period.minDelay(),
delay_t(from->clkconstr->period.minDelay() / ratio)) &&
user_constrained.count(to->name))
log_warning(
" Overriding derived constraint of %.2f MHz on net %s with user-specified constraint of "
"%.2f MHz.\n",
MHz(to->clkconstr->period.minDelay()), to->name.c_str(ctx),
MHz(delay_t(from->clkconstr->period.minDelay() / ratio)));
return;
}
to->clkconstr = std::unique_ptr<ClockConstraint>(new ClockConstraint());
to->clkconstr->low =
DelayPair(ctx->getDelayFromNS(ctx->getDelayNS(from->clkconstr->low.min_delay) / ratio));
to->clkconstr->high =
DelayPair(ctx->getDelayFromNS(ctx->getDelayNS(from->clkconstr->high.min_delay) / ratio));
to->clkconstr->period =
DelayPair(ctx->getDelayFromNS(ctx->getDelayNS(from->clkconstr->period.min_delay) / ratio));
log_info(" Derived frequency constraint of %.2f MHz for net %s\n", MHz(to->clkconstr->period.minDelay()),
to->name.c_str(ctx));
changed_nets.insert(to->name);
};
// Run in a loop while constraints are changing to deal with dependencies
// Iteration limit avoids hanging in crazy loopback situation (self-fed PLLs or dividers, etc)
int iter = 0;
const int itermax = 5000;
while (!changed_nets.empty() && iter < itermax) {
++iter;
pool<IdString> changed_cells;
for (auto net : changed_nets) {
for (auto &user : ctx->nets.at(net)->users)
if (user.port.in(id_CLKI, id_ECLKI, id_CLK0, id_CLK1))
changed_cells.insert(user.cell->name);
auto &drv = ctx->nets.at(net)->driver;
if (iter == 1 && drv.cell != nullptr && drv.port == id_OSC)
changed_cells.insert(drv.cell->name);
}
changed_nets.clear();
for (auto cell : changed_cells) {
CellInfo *ci = ctx->cells.at(cell).get();
if (ci->type == id_CLKDIVC) {
std::string div = str_or_default(ci->params, id_DIV, "2.0");
double ratio;
if (div == "2.0")
ratio = 1 / 2.0;
else if (div == "3.5")
ratio = 1 / 3.5;
else if (div == "4.0")
ratio = 1 / 4.0;
else
log_error("Unsupported divider ratio '%s' on CLKDIVC '%s'\n", div.c_str(), ci->name.c_str(ctx));
copy_constraint(ci, id_CLKI, id_CDIVX, ratio);
} else if (ci->type.in(id_ECLKSYNCA /*, id_TRELLIS_ECLKBUF*/)) {
copy_constraint(ci, id_ECLKI, id_ECLKO, 1);
} else if (ci->type == id_ECLKBRIDGECS) {
copy_constraint(ci, id_CLK0, id_ECSOUT, 1);
copy_constraint(ci, id_CLK1, id_ECSOUT, 1);
} else if (ci->type == id_DCCA) {
copy_constraint(ci, id_CLKI, id_CLKO, 1);
} else if (ci->type == id_EHXPLLJ) {
delay_t period_in;
if (!get_period(ci, id_CLKI, period_in))
continue;
log_info(" Input frequency of PLL '%s' is constrained to %.2f MHz\n", ci->name.c_str(ctx),
MHz(period_in));
double period_in_div = period_in * int_or_default(ci->params, id_CLKI_DIV, 1);
std::string path = str_or_default(ci->params, id_FEEDBK_PATH, "CLKOP");
int feedback_div = int_or_default(ci->params, id_CLKFB_DIV, 1);
if (path == "CLKOP" || path == "INT_OP")
feedback_div *= int_or_default(ci->params, id_CLKOP_DIV, 1);
else if (path == "CLKOS" || path == "INT_OS")
feedback_div *= int_or_default(ci->params, id_CLKOS_DIV, 1);
else if (path == "CLKOS2" || path == "INT_OS2")
feedback_div *= int_or_default(ci->params, id_CLKOS2_DIV, 1);
else if (path == "CLKOS3" || path == "INT_OS3")
feedback_div *= int_or_default(ci->params, id_CLKOS3_DIV, 1);
else {
log_info(" Unable to determine output frequencies for PLL '%s' with FEEDBK_PATH=%s\n",
ci->name.c_str(ctx), path.c_str());
continue;
}
double vco_period = period_in_div / feedback_div;
double vco_freq = MHz(vco_period);
if (vco_freq < 400 || vco_freq > 800)
log_info(" Derived VCO frequency %.2f MHz of PLL '%s' is out of legal range [400MHz, "
"800MHz]\n",
vco_freq, ci->name.c_str(ctx));
set_constraint(ci, id_CLKOP,
simple_clk_contraint(vco_period * int_or_default(ci->params, id_CLKOP_DIV, 1)));
set_constraint(ci, id_CLKOS,
simple_clk_contraint(vco_period * int_or_default(ci->params, id_CLKOS_DIV, 1)));
set_constraint(ci, id_CLKOS2,
simple_clk_contraint(vco_period * int_or_default(ci->params, id_CLKOS2_DIV, 1)));
set_constraint(ci, id_CLKOS3,
simple_clk_contraint(vco_period * int_or_default(ci->params, id_CLKOS3_DIV, 1)));
} else if (ci->type == id_OSCH || ci->type == id_OSCJ) {
static std::string const osc_freq[] = {
"2.08", "2.15", "2.22", "2.29", "2.38", "2.46", "2.56", "2.66", "2.77", "2.89",
"3.02", "3.17", "3.33", "3.50", "3.69", "3.91", "4.16", "4.29", "4.43", "4.59",
"4.75", "4.93", "5.12", "5.32", "5.54", "5.78", "6.05", "6.33", "6.65", "7.00",
"7.39", "7.82", "8.31", "8.58", "8.87", "9.17", "9.50", "9.85", "10.23", "10.64",
"11.08", "11.57", "12.09", "12.67", "13.30", "14.00", "14.78", "15.65", "15.65", "16.63",
"17.73", "19.00", "20.46", "22.17", "24.18", "26.60", "29.56", "33.25", "38.00", "44.33",
"53.20", "66.50", "88.67", "133.00"};
std::string freq = str_or_default(ci->params, id_NOM_FREQ, "2.08");
bool found = false;
for (int i = 0; i < 64; i++) {
if (osc_freq[i] == freq) {
found = true;
set_constraint(ci, id_OSC, simple_clk_contraint(delay_t(1.0e6 / std::stof(freq))));
break;
}
}
if (!found)
log_error("Unsupported frequency '%s' on %s '%s'\n", freq.c_str(), ci->type.c_str(ctx),
ci->name.c_str(ctx));
}
}
}
}
void prepack_checks()
{
// Check for legacy-style JSON (use CEMUX as a clue) and error out, avoiding a confusing assertion failure
// later
for (auto &cell : ctx->cells) {
if (is_ff(ctx, cell.second.get()) && cell.second->params.count(id_CEMUX) &&
!cell.second->params[id_CEMUX].is_string)
log_error("Found netlist using legacy-style JSON parameter values, please update your Yosys.\n");
}
}
BelId get_bel_attr(const CellInfo *ci)
{
if (!ci->attrs.count(id_BEL))
return BelId();
return ctx->getBelByNameStr(ci->attrs.at(id_BEL).as_string());
}
// Using a BFS, search for bels of a given type either upstream or downstream of another cell
void find_connected_bels(const CellInfo *cell, IdString port, IdString dest_type, IdString dest_pin, int iter_limit,
std::vector<BelId> &candidates)
{
int iter = 0;
std::queue<WireId> visit;
pool<WireId> seen_wires;
pool<BelId> seen_bels;
BelId bel = get_bel_attr(cell);
if (bel == BelId())
return;
WireId start_wire = ctx->getBelPinWire(bel, port);
NPNR_ASSERT(start_wire != WireId());
PortType dir = ctx->getBelPinType(bel, port);
visit.push(start_wire);
while (!visit.empty() && (iter++ < iter_limit)) {
WireId cursor = visit.front();
visit.pop();
// Check to see if we have reached a valid bel pin
for (auto bp : ctx->getWireBelPins(cursor)) {
if (ctx->getBelType(bp.bel) != dest_type)
continue;
if (dest_pin != IdString() && bp.pin != dest_pin)
continue;
if (seen_bels.count(bp.bel))
continue;
seen_bels.insert(bp.bel);
candidates.push_back(bp.bel);
}
// Search in the appropriate direction up/downstream of the cursor
if (dir == PORT_OUT) {
for (PipId p : ctx->getPipsDownhill(cursor))
if (ctx->checkPipAvail(p)) {
WireId dst = ctx->getPipDstWire(p);
if (seen_wires.count(dst))
continue;
seen_wires.insert(dst);
visit.push(dst);
}
} else {
for (PipId p : ctx->getPipsUphill(cursor))
if (ctx->checkPipAvail(p)) {
WireId src = ctx->getPipSrcWire(p);
if (seen_wires.count(src))
continue;
seen_wires.insert(src);
visit.push(src);
}
}
}
}
// Find the nearest bel of a given type; matching a closure predicate
template <typename Tpred> BelId find_nearest_bel(const CellInfo *cell, IdString dest_type, Tpred predicate)
{
BelId origin = get_bel_attr(cell);
if (origin == BelId())
return BelId();
Loc origin_loc = ctx->getBelLocation(origin);
int best_distance = std::numeric_limits<int>::max();
BelId best_bel = BelId();
for (BelId bel : ctx->getBels()) {
if (ctx->getBelType(bel) != dest_type)
continue;
if (!predicate(bel))
continue;
Loc bel_loc = ctx->getBelLocation(bel);
int dist = std::abs(origin_loc.x - bel_loc.x) + std::abs(origin_loc.y - bel_loc.y);
if (dist < best_distance) {
best_distance = dist;
best_bel = bel;
}
}
return best_bel;
}
pool<BelId> used_bels;
// Pre-place a primitive based on routeability first and distance second
bool preplace_prim(CellInfo *cell, IdString pin, bool strict_routing)
{
std::vector<BelId> routeability_candidates;
if (cell->attrs.count(id_BEL))
return false;
NetInfo *pin_net = cell->getPort(pin);
if (pin_net == nullptr)
return false;
CellInfo *pin_drv = pin_net->driver.cell;
if (pin_drv == nullptr)
return false;
// Check based on routeability
find_connected_bels(pin_drv, pin_net->driver.port, cell->type, pin, 25000, routeability_candidates);
for (BelId cand : routeability_candidates) {
if (used_bels.count(cand))
continue;
log_info(" constraining %s '%s' to bel '%s' based on dedicated routing\n", ctx->nameOf(cell),
ctx->nameOf(cell->type), ctx->nameOfBel(cand));
cell->attrs[id_BEL] = ctx->getBelName(cand).str(ctx);
used_bels.insert(cand);
return true;
}
// Unless in strict mode; check based on simple distance too
BelId nearest = find_nearest_bel(pin_drv, cell->type, [&](BelId bel) { return !used_bels.count(bel); });
if (nearest != BelId()) {
log_info(" constraining %s '%s' to bel '%s'\n", ctx->nameOf(cell), ctx->nameOf(cell->type),
ctx->nameOfBel(nearest));
cell->attrs[id_BEL] = ctx->getBelName(nearest).str(ctx);
used_bels.insert(nearest);
return true;
}
return false;
}
// Pre-place a singleton primitive; so decisions can be made on routeability downstream of it
bool preplace_singleton(CellInfo *cell)
{
if (cell->attrs.count(id_BEL))
return false;
bool did_something = false;
for (BelId bel : ctx->getBels()) {
if (ctx->getBelType(bel) != cell->type)
continue;
// Check that the bel really is a singleton...
NPNR_ASSERT(!cell->attrs.count(id_BEL));
cell->attrs[id_BEL] = ctx->getBelName(bel).str(ctx);
log_info(" constraining %s '%s' to bel '%s'\n", ctx->nameOf(cell), ctx->nameOf(cell->type),
ctx->nameOfBel(bel));
did_something = true;
}
return did_something;
}
// Insert a buffer primitive in a signal; moving all users that match a predicate behind it
template <typename Tpred>
CellInfo *insert_buffer(NetInfo *net, IdString buffer_type, std::string name_postfix, IdString i, IdString o,
Tpred pred)
{
// Create the buffered net
NetInfo *buffered_net = ctx->createNet(ctx->idf("%s$%s", ctx->nameOf(net), name_postfix.c_str()));
// Create the buffer cell
CellInfo *buffer = ctx->createCell(ctx->idf("%s$drv_%s", ctx->nameOf(buffered_net), ctx->nameOf(buffer_type)),
buffer_type);
buffer->addInput(i);
buffer->addOutput(o);
// Drive the buffered net with the buffer
buffer->connectPort(o, buffered_net);
// Filter users
std::vector<PortRef> remaining_users;
for (auto &usr : net->users) {
if (pred(usr)) {
usr.cell->ports[usr.port].net = buffered_net;
usr.cell->ports[usr.port].user_idx = buffered_net->users.add(usr);
} else {
remaining_users.push_back(usr);
}
}
net->users.clear();
for (auto &usr : remaining_users)
usr.cell->ports.at(usr.port).user_idx = net->users.add(usr);
// Connect buffer input to original net
buffer->connectPort(i, net);
return buffer;
}
// Insert global buffers
void promote_globals()
{
std::vector<std::pair<int, IdString>> clk_fanout;
int available_globals = 8;
for (auto &net : ctx->nets) {
NetInfo *ni = net.second.get();
// Skip undriven nets; and nets that are already global
if (ni->driver.cell == nullptr)
continue;
if (ni->name.in(ctx->id("$PACKER_GND_NET"), ctx->id("$PACKER_VCC_NET")))
continue;
if (ni->driver.cell->type == id_DCMA) {
continue;
}
if (ni->driver.cell->type == id_DCCA) {
--available_globals;
continue;
}
// Count the number of clock ports
int clk_count = 0;
for (const auto &usr : ni->users) {
if (usr.cell->type == id_TRELLIS_FF && usr.port == id_CLK)
clk_count++;
if (usr.cell->type == id_DP8KC && usr.port.in(id_CLKA, id_CLKB))
clk_count++;
}
if (clk_count > 0)
clk_fanout.emplace_back(clk_count, ni->name);
}
if (available_globals <= 0)
return;
// Sort clocks by max fanout
std::sort(clk_fanout.begin(), clk_fanout.end(), std::greater<std::pair<int, IdString>>());
log_info("Promoting globals...\n");
// Promote the N highest fanout clocks
for (size_t i = 0; i < std::min<size_t>(clk_fanout.size(), available_globals); i++) {
NetInfo *net = ctx->nets.at(clk_fanout.at(i).second).get();
log_info(" promoting clock net '%s'\n", ctx->nameOf(net));
insert_buffer(net, id_DCCA, "glb_clk", id_CLKI, id_CLKO,
[&](const PortRef &port) { return port.cell->type != id_DCCA; });
}
}
// Place certain global cells
void place_globals()
{
// Keep running until we reach a fixed point
log_info("Placing globals...\n");
bool did_something = true;
while (did_something) {
did_something = false;
for (auto &cell : ctx->cells) {
CellInfo *ci = cell.second.get();
if (ci->type == id_OSCH)
did_something |= preplace_singleton(ci);
else if (ci->type == id_DCCA)
did_something |= preplace_prim(ci, id_CLKI, false);
else if (ci->type == id_EHXPLLJ)
did_something |= preplace_prim(ci, id_CLKI, false);
}
}
}
public:
void pack()
{
prepack_checks();
print_logic_usage();
pack_io();
pack_ebr();
pack_misc();
pack_constants();
pack_dram();
pack_carries();
pack_luts();
pack_lut5xs();
pack_ffs();
promote_globals();
place_globals();
generate_constraints();
ctx->fixupHierarchy();
ctx->check();
}
private:
Context *ctx;
pool<IdString> packed_cells;
std::vector<std::unique_ptr<CellInfo>> new_cells;
struct SliceUsage
{
bool lut0_used = false, lut1_used = false;
bool ccu2_used = false, dpram_used = false, ramw_used = false;
bool ff0_used = false, ff1_used = false;
bool mux5_used = false, muxx_used = false;
};
dict<IdString, SliceUsage> sliceUsage;
dict<IdString, IdString> lutffPairs;
dict<IdString, IdString> fflutPairs;
dict<IdString, IdString> lutPairs;
};
// Main pack function
bool Arch::pack()
{
Context *ctx = getCtx();
try {
log_break();
MachXO2Packer(ctx).pack();
log_info("Checksum: 0x%08x\n", ctx->checksum());
assignArchInfo();
ctx->settings[id_pack] = 1;
archInfoToAttributes();
return true;
} catch (log_execution_error_exception) {
assignArchInfo();
return false;
}
}
void Arch::assign_arch_info_for_cell(CellInfo *ci)
{
auto get_port_net = [&](CellInfo *ci, IdString p) {
NetInfo *n = ci->getPort(p);
return n ? n->name : IdString();
};
if (ci->type == id_TRELLIS_COMB) {
std::string mode = str_or_default(ci->params, id_MODE, "LOGIC");
ci->combInfo.flags = ArchCellInfo::COMB_NONE;
if (mode == "CCU2")
ci->combInfo.flags |= ArchCellInfo::COMB_CARRY;
if (mode == "DPRAM") {
ci->combInfo.flags |= ArchCellInfo::COMB_LUTRAM;
std::string wckmux = str_or_default(ci->params, id_WCKMUX, "WCK");
if (wckmux == "INV")
ci->combInfo.flags |= ArchCellInfo::COMB_RAM_WCKINV;
std::string wremux = str_or_default(ci->params, id_WREMUX, "WRE");
if (wremux == "INV" || wremux == "0")
ci->combInfo.flags |= ArchCellInfo::COMB_RAM_WREINV;
ci->combInfo.ram_wck = get_port_net(ci, id_WCK);
ci->combInfo.ram_wre = get_port_net(ci, id_WRE);
}
if (mode == "RAMW_BLOCK")
ci->combInfo.flags |= ArchCellInfo::COMB_RAMW_BLOCK;
if (ci->getPort(id_F1) != nullptr)
ci->combInfo.flags |= ArchCellInfo::COMB_MUX5;
if (ci->getPort(id_FXA) != nullptr || ci->getPort(id_FXB) != nullptr) {
ci->combInfo.flags |= ArchCellInfo::COMB_MUX6;
NetInfo *fxa = ci->getPort(id_FXA);
if (fxa != nullptr)
ci->combInfo.mux_fxad = fxa->driver.cell;
}
} else if (ci->type == id_TRELLIS_FF) {
ci->ffInfo.flags = ArchCellInfo::FF_NONE;
if (str_or_default(ci->params, id_GSR, "ENABLED") == "ENABLED")
ci->ffInfo.flags |= ArchCellInfo::FF_GSREN;
if (str_or_default(ci->params, id_SRMODE, "LSR_OVER_CE") == "ASYNC")
ci->ffInfo.flags |= ArchCellInfo::FF_ASYNC;
if (ci->getPort(id_M) != nullptr)
ci->ffInfo.flags |= ArchCellInfo::FF_M_USED;
std::string clkmux = str_or_default(ci->params, id_CLKMUX, "CLK");
std::string cemux = str_or_default(ci->params, id_CEMUX, "CE");
std::string lsrmux = str_or_default(ci->params, id_LSRMUX, "LSR");
if (clkmux == "INV" || clkmux == "0")
ci->ffInfo.flags |= ArchCellInfo::FF_CLKINV;
if (cemux == "INV" || cemux == "0")
ci->ffInfo.flags |= ArchCellInfo::FF_CEINV;
if (cemux == "1" || cemux == "0")
ci->ffInfo.flags |= ArchCellInfo::FF_CECONST;
if (lsrmux == "INV")
ci->ffInfo.flags |= ArchCellInfo::FF_LSRINV;
ci->ffInfo.clk_sig = get_port_net(ci, id_CLK);
ci->ffInfo.ce_sig = get_port_net(ci, id_CE);
ci->ffInfo.lsr_sig = get_port_net(ci, id_LSR);
} else if (ci->type == id_DP8KC) {
ci->ramInfo.is_pdp = (int_or_default(ci->params, id_DATA_WIDTH_A, 0) == 18);
// Output register mode (REGMODE_{A,B}). Valid options are 'NOREG' and 'OUTREG'.
std::string regmode_a = str_or_default(ci->params, id_REGMODE_A, "NOREG");
if (regmode_a != "NOREG" && regmode_a != "OUTREG")
log_error("DP8KC %s has invalid REGMODE_A configuration '%s'\n", ci->name.c_str(this), regmode_a.c_str());
std::string regmode_b = str_or_default(ci->params, id_REGMODE_B, "NOREG");
if (regmode_b != "NOREG" && regmode_b != "OUTREG")
log_error("DP8KC %s has invalid REGMODE_B configuration '%s'\n", ci->name.c_str(this), regmode_b.c_str());
ci->ramInfo.is_output_a_registered = regmode_a == "OUTREG";
ci->ramInfo.is_output_b_registered = regmode_b == "OUTREG";
// Based on the REGMODE, we have different timing lookup tables.
if (!ci->ramInfo.is_output_a_registered && !ci->ramInfo.is_output_b_registered) {
ci->ramInfo.regmode_timing_id = id_DP8KC_REGMODE_A_NOREG_REGMODE_B_NOREG;
} else if (!ci->ramInfo.is_output_a_registered && ci->ramInfo.is_output_b_registered) {
ci->ramInfo.regmode_timing_id = id_DP8KC_REGMODE_A_NOREG_REGMODE_B_OUTREG;
} else if (ci->ramInfo.is_output_a_registered && !ci->ramInfo.is_output_b_registered) {
ci->ramInfo.regmode_timing_id = id_DP8KC_REGMODE_A_OUTREG_REGMODE_B_NOREG;
} else if (ci->ramInfo.is_output_a_registered && ci->ramInfo.is_output_b_registered) {
ci->ramInfo.regmode_timing_id = id_DP8KC_REGMODE_A_OUTREG_REGMODE_B_OUTREG;
}
}
}
void Arch::assignArchInfo()
{
for (auto &cell : cells) {
CellInfo *ci = cell.second.get();
assign_arch_info_for_cell(ci);
}
}
NEXTPNR_NAMESPACE_END