nextpnr/ice40/pack.cc
Sylvain Munaut ac5d767d4f ice40/pack: Stop looking for BEL when we have one during PLL placement
Ideally we should first process all the PLL that are constrained somehow
(either explicitely or because they are PAD) and then free place the rest.

Signed-off-by: Sylvain Munaut <tnt@246tNt.com>
2018-11-19 18:20:20 +01:00

1005 lines
45 KiB
C++

/*
* nextpnr -- Next Generation Place and Route
*
* Copyright (C) 2018 Clifford Wolf <clifford@symbioticeda.com>
* Copyright (C) 2018 David Shah <david@symbioticeda.com>
* Copyright (C) 2018 Serge Bazanski <q3k@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 <algorithm>
#include <iterator>
#include <unordered_set>
#include "cells.h"
#include "chains.h"
#include "design_utils.h"
#include "log.h"
#include "util.h"
NEXTPNR_NAMESPACE_BEGIN
// Pack LUTs and LUT-FF pairs
static void pack_lut_lutffs(Context *ctx)
{
log_info("Packing LUT-FFs..\n");
std::unordered_set<IdString> packed_cells;
std::vector<std::unique_ptr<CellInfo>> new_cells;
for (auto cell : sorted(ctx->cells)) {
CellInfo *ci = cell.second;
if (ctx->verbose)
log_info("cell '%s' is of type '%s'\n", ci->name.c_str(ctx), ci->type.c_str(ctx));
if (is_lut(ctx, ci)) {
std::unique_ptr<CellInfo> packed = create_ice_cell(ctx, ctx->id("ICESTORM_LC"), ci->name.str(ctx) + "_LC");
std::copy(ci->attrs.begin(), ci->attrs.end(), std::inserter(packed->attrs, packed->attrs.begin()));
packed_cells.insert(ci->name);
if (ctx->verbose)
log_info("packed cell %s into %s\n", ci->name.c_str(ctx), packed->name.c_str(ctx));
// See if we can pack into a DFF
// TODO: LUT cascade
NetInfo *o = ci->ports.at(ctx->id("O")).net;
CellInfo *dff = net_only_drives(ctx, o, is_ff, ctx->id("D"), true);
auto lut_bel = ci->attrs.find(ctx->id("BEL"));
bool packed_dff = false;
if (dff) {
if (ctx->verbose)
log_info("found attached dff %s\n", dff->name.c_str(ctx));
auto dff_bel = dff->attrs.find(ctx->id("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(ctx, ci, packed.get(), false);
dff_to_lc(ctx, dff, packed.get(), false);
ctx->nets.erase(o->name);
if (dff_bel != dff->attrs.end())
packed->attrs[ctx->id("BEL")] = dff_bel->second;
packed_cells.insert(dff->name);
if (ctx->verbose)
log_info("packed cell %s into %s\n", dff->name.c_str(ctx), packed->name.c_str(ctx));
packed_dff = true;
}
}
if (!packed_dff) {
lut_to_lc(ctx, ci, packed.get(), true);
}
new_cells.push_back(std::move(packed));
}
}
for (auto pcell : packed_cells) {
ctx->cells.erase(pcell);
}
for (auto &ncell : new_cells) {
ctx->cells[ncell->name] = std::move(ncell);
}
}
// Pack FFs not packed as LUTFFs
static void pack_nonlut_ffs(Context *ctx)
{
log_info("Packing non-LUT FFs..\n");
std::unordered_set<IdString> packed_cells;
std::vector<std::unique_ptr<CellInfo>> new_cells;
for (auto cell : sorted(ctx->cells)) {
CellInfo *ci = cell.second;
if (is_ff(ctx, ci)) {
std::unique_ptr<CellInfo> packed =
create_ice_cell(ctx, ctx->id("ICESTORM_LC"), ci->name.str(ctx) + "_DFFLC");
std::copy(ci->attrs.begin(), ci->attrs.end(), std::inserter(packed->attrs, packed->attrs.begin()));
if (ctx->verbose)
log_info("packed cell %s into %s\n", ci->name.c_str(ctx), packed->name.c_str(ctx));
packed_cells.insert(ci->name);
dff_to_lc(ctx, ci, packed.get(), true);
new_cells.push_back(std::move(packed));
}
}
for (auto pcell : packed_cells) {
ctx->cells.erase(pcell);
}
for (auto &ncell : new_cells) {
ctx->cells[ncell->name] = std::move(ncell);
}
}
static bool net_is_constant(const Context *ctx, NetInfo *net, bool &value)
{
if (net == nullptr)
return false;
if (net->name == ctx->id("$PACKER_GND_NET") || net->name == ctx->id("$PACKER_VCC_NET")) {
value = (net->name == ctx->id("$PACKER_VCC_NET"));
return true;
} else {
return false;
}
}
// Pack carry logic
static void pack_carries(Context *ctx)
{
log_info("Packing carries..\n");
std::unordered_set<IdString> exhausted_cells;
std::unordered_set<IdString> packed_cells;
std::vector<std::unique_ptr<CellInfo>> new_cells;
for (auto cell : sorted(ctx->cells)) {
CellInfo *ci = cell.second;
if (is_carry(ctx, ci)) {
packed_cells.insert(cell.first);
CellInfo *carry_ci_lc;
bool ci_value;
bool ci_const = net_is_constant(ctx, ci->ports.at(ctx->id("CI")).net, ci_value);
if (ci_const) {
carry_ci_lc = nullptr;
} else {
carry_ci_lc = net_only_drives(ctx, ci->ports.at(ctx->id("CI")).net, is_lc, ctx->id("I3"), false);
}
std::set<IdString> i0_matches, i1_matches;
NetInfo *i0_net = ci->ports.at(ctx->id("I0")).net;
NetInfo *i1_net = ci->ports.at(ctx->id("I1")).net;
// Find logic cells connected to both I0 and I1
if (i0_net) {
for (auto usr : i0_net->users) {
if (is_lc(ctx, usr.cell) && usr.port == ctx->id("I1")) {
if (ctx->cells.find(usr.cell->name) != ctx->cells.end() &&
exhausted_cells.find(usr.cell->name) == exhausted_cells.end()) {
// This clause stops us double-packing cells
i0_matches.insert(usr.cell->name);
if (!i1_net && !usr.cell->ports.at(ctx->id("I2")).net) {
// I1 is don't care when disconnected, duplicate I0
i1_matches.insert(usr.cell->name);
}
}
}
}
}
if (i1_net) {
for (auto usr : i1_net->users) {
if (is_lc(ctx, usr.cell) && usr.port == ctx->id("I2")) {
if (ctx->cells.find(usr.cell->name) != ctx->cells.end() &&
exhausted_cells.find(usr.cell->name) == exhausted_cells.end()) {
// This clause stops us double-packing cells
i1_matches.insert(usr.cell->name);
if (!i0_net && !usr.cell->ports.at(ctx->id("I1")).net) {
// I0 is don't care when disconnected, duplicate I1
i0_matches.insert(usr.cell->name);
}
}
}
}
}
std::set<IdString> carry_lcs;
std::set_intersection(i0_matches.begin(), i0_matches.end(), i1_matches.begin(), i1_matches.end(),
std::inserter(carry_lcs, carry_lcs.end()));
CellInfo *carry_lc = nullptr;
if (carry_ci_lc && carry_lcs.find(carry_ci_lc->name) != carry_lcs.end()) {
carry_lc = carry_ci_lc;
} else {
// No LC to pack into matching I0/I1, insert a new one
std::unique_ptr<CellInfo> created_lc =
create_ice_cell(ctx, ctx->id("ICESTORM_LC"), cell.first.str(ctx) + "$CARRY");
carry_lc = created_lc.get();
created_lc->ports.at(ctx->id("I1")).net = i0_net;
if (i0_net) {
PortRef pr;
pr.cell = created_lc.get();
pr.port = ctx->id("I1");
i0_net->users.push_back(pr);
}
created_lc->ports.at(ctx->id("I2")).net = i1_net;
if (i1_net) {
PortRef pr;
pr.cell = created_lc.get();
pr.port = ctx->id("I2");
i1_net->users.push_back(pr);
}
new_cells.push_back(std::move(created_lc));
}
carry_lc->params[ctx->id("CARRY_ENABLE")] = "1";
replace_port(ci, ctx->id("CI"), carry_lc, ctx->id("CIN"));
replace_port(ci, ctx->id("CO"), carry_lc, ctx->id("COUT"));
if (i0_net) {
auto &i0_usrs = i0_net->users;
i0_usrs.erase(std::remove_if(i0_usrs.begin(), i0_usrs.end(), [ci, ctx](const PortRef &pr) {
return pr.cell == ci && pr.port == ctx->id("I0");
}));
}
if (i1_net) {
auto &i1_usrs = i1_net->users;
i1_usrs.erase(std::remove_if(i1_usrs.begin(), i1_usrs.end(), [ci, ctx](const PortRef &pr) {
return pr.cell == ci && pr.port == ctx->id("I1");
}));
}
// Check for constant driver on CIN
if (carry_lc->ports.at(ctx->id("CIN")).net != nullptr) {
IdString cin_net = carry_lc->ports.at(ctx->id("CIN")).net->name;
if (cin_net == ctx->id("$PACKER_GND_NET") || cin_net == ctx->id("$PACKER_VCC_NET")) {
carry_lc->params[ctx->id("CIN_CONST")] = "1";
carry_lc->params[ctx->id("CIN_SET")] = cin_net == ctx->id("$PACKER_VCC_NET") ? "1" : "0";
carry_lc->ports.at(ctx->id("CIN")).net = nullptr;
auto &cin_users = ctx->nets.at(cin_net)->users;
cin_users.erase(
std::remove_if(cin_users.begin(), cin_users.end(), [carry_lc, ctx](const PortRef &pr) {
return pr.cell == carry_lc && pr.port == ctx->id("CIN");
}));
}
}
exhausted_cells.insert(carry_lc->name);
}
}
for (auto pcell : packed_cells) {
ctx->cells.erase(pcell);
}
for (auto &ncell : new_cells) {
ctx->cells[ncell->name] = std::move(ncell);
}
}
// "Pack" RAMs
static void pack_ram(Context *ctx)
{
log_info("Packing RAMs..\n");
std::unordered_set<IdString> packed_cells;
std::vector<std::unique_ptr<CellInfo>> new_cells;
for (auto cell : sorted(ctx->cells)) {
CellInfo *ci = cell.second;
if (is_ram(ctx, ci)) {
std::unique_ptr<CellInfo> packed =
create_ice_cell(ctx, ctx->id("ICESTORM_RAM"), ci->name.str(ctx) + "_RAM");
packed_cells.insert(ci->name);
for (auto param : ci->params)
packed->params[param.first] = param.second;
packed->params[ctx->id("NEG_CLK_W")] =
std::to_string(ci->type == ctx->id("SB_RAM40_4KNW") || ci->type == ctx->id("SB_RAM40_4KNRNW"));
packed->params[ctx->id("NEG_CLK_R")] =
std::to_string(ci->type == ctx->id("SB_RAM40_4KNR") || ci->type == ctx->id("SB_RAM40_4KNRNW"));
packed->type = ctx->id("ICESTORM_RAM");
for (auto port : ci->ports) {
PortInfo &pi = port.second;
std::string newname = pi.name.str(ctx);
size_t bpos = newname.find('[');
if (bpos != std::string::npos) {
newname = newname.substr(0, bpos) + "_" + newname.substr(bpos + 1, (newname.size() - bpos) - 2);
}
if (pi.name == ctx->id("RCLKN"))
newname = "RCLK";
else if (pi.name == ctx->id("WCLKN"))
newname = "WCLK";
replace_port(ci, ctx->id(pi.name.c_str(ctx)), packed.get(), ctx->id(newname));
}
new_cells.push_back(std::move(packed));
}
}
for (auto pcell : packed_cells) {
ctx->cells.erase(pcell);
}
for (auto &ncell : new_cells) {
ctx->cells[ncell->name] = std::move(ncell);
}
}
// Merge a net into a constant net
static 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) || is_lc(ctx, uc) || is_carry(ctx, uc)) && (user.port.str(ctx).at(0) == 'I') &&
!constval) {
uc->ports[user.port].net = nullptr;
} else if ((is_sb_mac16(ctx, uc) || uc->type == ctx->id("ICESTORM_DSP")) &&
(user.port != ctx->id("CLK") &&
((constval && user.port == ctx->id("CE")) || (!constval && user.port != ctx->id("CE"))))) {
uc->ports[user.port].net = nullptr;
} else if (is_ram(ctx, uc) && !constval && user.port != ctx->id("RCLK") && user.port != ctx->id("RCLKN") &&
user.port != ctx->id("WCLK") && user.port != ctx->id("WCLKN") && user.port != ctx->id("RCLKE") &&
user.port != ctx->id("WCLKE")) {
uc->ports[user.port].net = nullptr;
} else {
uc->ports[user.port].net = constnet;
constnet->users.push_back(user);
}
}
}
orig->users.clear();
}
// Pack constants (simple implementation)
static void pack_constants(Context *ctx)
{
log_info("Packing constants..\n");
std::unique_ptr<CellInfo> gnd_cell = create_ice_cell(ctx, ctx->id("ICESTORM_LC"), "$PACKER_GND");
gnd_cell->params[ctx->id("LUT_INIT")] = "0";
std::unique_ptr<NetInfo> gnd_net = std::unique_ptr<NetInfo>(new NetInfo);
gnd_net->name = ctx->id("$PACKER_GND_NET");
gnd_net->driver.cell = gnd_cell.get();
gnd_net->driver.port = ctx->id("O");
gnd_cell->ports.at(ctx->id("O")).net = gnd_net.get();
std::unique_ptr<CellInfo> vcc_cell = create_ice_cell(ctx, ctx->id("ICESTORM_LC"), "$PACKER_VCC");
vcc_cell->params[ctx->id("LUT_INIT")] = "1";
std::unique_ptr<NetInfo> vcc_net = std::unique_ptr<NetInfo>(new NetInfo);
vcc_net->name = ctx->id("$PACKER_VCC_NET");
vcc_net->driver.cell = vcc_cell.get();
vcc_net->driver.port = ctx->id("O");
vcc_cell->ports.at(ctx->id("O")).net = vcc_net.get();
std::vector<IdString> dead_nets;
bool gnd_used = false;
for (auto net : sorted(ctx->nets)) {
NetInfo *ni = net.second;
if (ni->driver.cell != nullptr && ni->driver.cell->type == ctx->id("GND")) {
IdString drv_cell = ni->driver.cell->name;
set_net_constant(ctx, ni, gnd_net.get(), false);
gnd_used = true;
dead_nets.push_back(net.first);
ctx->cells.erase(drv_cell);
} else if (ni->driver.cell != nullptr && ni->driver.cell->type == ctx->id("VCC")) {
IdString drv_cell = ni->driver.cell->name;
set_net_constant(ctx, ni, vcc_net.get(), true);
dead_nets.push_back(net.first);
ctx->cells.erase(drv_cell);
}
}
if (gnd_used) {
ctx->cells[gnd_cell->name] = std::move(gnd_cell);
ctx->nets[gnd_net->name] = std::move(gnd_net);
}
// Vcc cell always inserted for now, as it may be needed during carry legalisation (TODO: trim later if actually
// never used?)
ctx->cells[vcc_cell->name] = std::move(vcc_cell);
ctx->nets[vcc_net->name] = std::move(vcc_net);
for (auto dn : dead_nets) {
ctx->nets.erase(dn);
}
}
static bool is_nextpnr_iob(Context *ctx, CellInfo *cell)
{
return cell->type == ctx->id("$nextpnr_ibuf") || cell->type == ctx->id("$nextpnr_obuf") ||
cell->type == ctx->id("$nextpnr_iobuf");
}
// Pack IO buffers
static void pack_io(Context *ctx)
{
std::unordered_set<IdString> packed_cells;
std::unordered_set<IdString> delete_nets;
std::vector<std::unique_ptr<CellInfo>> new_cells;
log_info("Packing IOs..\n");
for (auto cell : sorted(ctx->cells)) {
CellInfo *ci = cell.second;
if (is_nextpnr_iob(ctx, ci)) {
CellInfo *sb = nullptr;
if (ci->type == ctx->id("$nextpnr_ibuf") || ci->type == ctx->id("$nextpnr_iobuf")) {
sb = net_only_drives(ctx, ci->ports.at(ctx->id("O")).net, is_sb_io, ctx->id("PACKAGE_PIN"), true, ci);
} else if (ci->type == ctx->id("$nextpnr_obuf")) {
sb = net_only_drives(ctx, ci->ports.at(ctx->id("I")).net, is_sb_io, ctx->id("PACKAGE_PIN"), true, ci);
}
if (sb != nullptr) {
// Trivial case, SB_IO used. Just destroy the net and the
// iobuf
log_info("%s feeds SB_IO %s, removing %s %s.\n", ci->name.c_str(ctx), sb->name.c_str(ctx),
ci->type.c_str(ctx), ci->name.c_str(ctx));
NetInfo *net = sb->ports.at(ctx->id("PACKAGE_PIN")).net;
if (((ci->type == ctx->id("$nextpnr_ibuf") || ci->type == ctx->id("$nextpnr_iobuf")) &&
net->users.size() > 1) ||
(ci->type == ctx->id("$nextpnr_obuf") && (net->users.size() > 2 || net->driver.cell != nullptr)))
log_error("PACKAGE_PIN of SB_IO '%s' connected to more than a single top level IO.\n",
sb->name.c_str(ctx));
if (net != nullptr) {
delete_nets.insert(net->name);
sb->ports.at(ctx->id("PACKAGE_PIN")).net = nullptr;
}
if (ci->type == ctx->id("$nextpnr_iobuf")) {
NetInfo *net2 = ci->ports.at(ctx->id("I")).net;
if (net2 != nullptr) {
delete_nets.insert(net2->name);
}
}
} else {
// Create a SB_IO buffer
std::unique_ptr<CellInfo> ice_cell =
create_ice_cell(ctx, ctx->id("SB_IO"), ci->name.str(ctx) + "$sb_io");
nxio_to_sb(ctx, ci, ice_cell.get(), packed_cells);
new_cells.push_back(std::move(ice_cell));
sb = new_cells.back().get();
}
packed_cells.insert(ci->name);
std::copy(ci->attrs.begin(), ci->attrs.end(), std::inserter(sb->attrs, sb->attrs.begin()));
} else if (is_sb_io(ctx, ci)) {
NetInfo *net = ci->ports.at(ctx->id("PACKAGE_PIN")).net;
if ((net != nullptr) && (net->users.size() > 1))
log_error("PACKAGE_PIN of SB_IO '%s' connected to more than a single top level IO.\n",
ci->name.c_str(ctx));
}
}
for (auto pcell : packed_cells) {
ctx->cells.erase(pcell);
}
for (auto dnet : delete_nets) {
ctx->nets.erase(dnet);
}
for (auto &ncell : new_cells) {
ctx->cells[ncell->name] = std::move(ncell);
}
}
// Return true if a port counts as "logic" for global promotion
static bool is_logic_port(BaseCtx *ctx, const PortRef &port)
{
if (is_clock_port(ctx, port) || is_reset_port(ctx, port) || is_enable_port(ctx, port))
return false;
return !is_sb_io(ctx, port.cell) && !is_sb_pll40(ctx, port.cell) && !is_sb_pll40_pad(ctx, port.cell) &&
port.cell->type != ctx->id("SB_GB");
}
static void insert_global(Context *ctx, NetInfo *net, bool is_reset, bool is_cen, bool is_logic)
{
log_info("promoting %s%s%s%s\n", net->name.c_str(ctx), is_reset ? " [reset]" : "", is_cen ? " [cen]" : "",
is_logic ? " [logic]" : "");
std::string glb_name = net->name.str(ctx) + std::string("_$glb_") + (is_reset ? "sr" : (is_cen ? "ce" : "clk"));
std::unique_ptr<CellInfo> gb = create_ice_cell(ctx, ctx->id("SB_GB"), "$gbuf_" + glb_name);
gb->ports[ctx->id("USER_SIGNAL_TO_GLOBAL_BUFFER")].net = net;
PortRef pr;
pr.cell = gb.get();
pr.port = ctx->id("USER_SIGNAL_TO_GLOBAL_BUFFER");
net->users.push_back(pr);
pr.cell = gb.get();
pr.port = ctx->id("GLOBAL_BUFFER_OUTPUT");
std::unique_ptr<NetInfo> glbnet = std::unique_ptr<NetInfo>(new NetInfo());
glbnet->name = ctx->id(glb_name);
glbnet->driver = pr;
gb->ports[ctx->id("GLOBAL_BUFFER_OUTPUT")].net = glbnet.get();
std::vector<PortRef> keep_users;
for (auto user : net->users) {
if (is_clock_port(ctx, user) || (is_reset && is_reset_port(ctx, user)) ||
(is_cen && is_enable_port(ctx, user)) || (is_logic && is_logic_port(ctx, user))) {
user.cell->ports[user.port].net = glbnet.get();
glbnet->users.push_back(user);
} else {
keep_users.push_back(user);
}
}
net->users = keep_users;
if (net->clkconstr) {
glbnet->clkconstr = std::unique_ptr<ClockConstraint>(new ClockConstraint());
glbnet->clkconstr->low = net->clkconstr->low;
glbnet->clkconstr->high = net->clkconstr->high;
glbnet->clkconstr->period = net->clkconstr->period;
}
ctx->nets[glbnet->name] = std::move(glbnet);
ctx->cells[gb->name] = std::move(gb);
}
// Simple global promoter (clock only)
static void promote_globals(Context *ctx)
{
log_info("Promoting globals..\n");
const int logic_fanout_thresh = 15;
const int enable_fanout_thresh = 5;
std::map<IdString, int> clock_count, reset_count, cen_count, logic_count;
for (auto net : sorted(ctx->nets)) {
NetInfo *ni = net.second;
if (ni->driver.cell != nullptr && !ctx->isGlobalNet(ni)) {
clock_count[net.first] = 0;
reset_count[net.first] = 0;
cen_count[net.first] = 0;
for (auto user : ni->users) {
if (is_clock_port(ctx, user))
clock_count[net.first]++;
if (is_reset_port(ctx, user))
reset_count[net.first]++;
if (is_enable_port(ctx, user))
cen_count[net.first]++;
if (is_logic_port(ctx, user))
logic_count[net.first]++;
}
}
}
int prom_globals = 0, prom_resets = 0, prom_cens = 0, prom_logics = 0;
int gbs_available = 8;
for (auto &cell : ctx->cells)
if (is_gbuf(ctx, cell.second.get()))
--gbs_available;
while (prom_globals < gbs_available) {
auto global_clock = std::max_element(clock_count.begin(), clock_count.end(),
[](const std::pair<IdString, int> &a, const std::pair<IdString, int> &b) {
return a.second < b.second;
});
auto global_reset = std::max_element(reset_count.begin(), reset_count.end(),
[](const std::pair<IdString, int> &a, const std::pair<IdString, int> &b) {
return a.second < b.second;
});
auto global_cen = std::max_element(cen_count.begin(), cen_count.end(),
[](const std::pair<IdString, int> &a, const std::pair<IdString, int> &b) {
return a.second < b.second;
});
auto global_logic = std::max_element(logic_count.begin(), logic_count.end(),
[](const std::pair<IdString, int> &a, const std::pair<IdString, int> &b) {
return a.second < b.second;
});
if (global_clock->second == 0 && prom_logics < 4 && global_logic->second > logic_fanout_thresh &&
(global_logic->second > global_cen->second || prom_cens >= 4) &&
(global_logic->second > global_reset->second || prom_resets >= 4)) {
NetInfo *logicnet = ctx->nets[global_logic->first].get();
insert_global(ctx, logicnet, false, false, true);
++prom_globals;
++prom_logics;
clock_count.erase(logicnet->name);
reset_count.erase(logicnet->name);
cen_count.erase(logicnet->name);
logic_count.erase(logicnet->name);
} else if (global_reset->second > global_clock->second && prom_resets < 4) {
NetInfo *rstnet = ctx->nets[global_reset->first].get();
insert_global(ctx, rstnet, true, false, false);
++prom_globals;
++prom_resets;
clock_count.erase(rstnet->name);
reset_count.erase(rstnet->name);
cen_count.erase(rstnet->name);
logic_count.erase(rstnet->name);
} else if (global_cen->second > global_clock->second && prom_cens < 4 &&
global_cen->second > enable_fanout_thresh) {
NetInfo *cennet = ctx->nets[global_cen->first].get();
insert_global(ctx, cennet, false, true, false);
++prom_globals;
++prom_cens;
clock_count.erase(cennet->name);
reset_count.erase(cennet->name);
cen_count.erase(cennet->name);
logic_count.erase(cennet->name);
} else if (global_clock->second != 0) {
NetInfo *clknet = ctx->nets[global_clock->first].get();
insert_global(ctx, clknet, false, false, false);
++prom_globals;
clock_count.erase(clknet->name);
reset_count.erase(clknet->name);
cen_count.erase(clknet->name);
logic_count.erase(clknet->name);
} else {
break;
}
}
}
// spliceLUT adds a pass-through LUT LC between the given cell's output port
// and either all users or only non_LUT users.
static std::unique_ptr<CellInfo> spliceLUT(Context *ctx, CellInfo *ci, IdString portId, bool onlyNonLUTs)
{
auto port = ci->ports[portId];
NPNR_ASSERT(port.net != nullptr);
// Create pass-through LUT.
std::unique_ptr<CellInfo> pt = create_ice_cell(ctx, ctx->id("ICESTORM_LC"),
ci->name.str(ctx) + "$nextpnr_" + portId.str(ctx) + "_lut_through");
pt->params[ctx->id("LUT_INIT")] = "65280"; // output is always I3
// Create LUT output net.
std::unique_ptr<NetInfo> out_net = std::unique_ptr<NetInfo>(new NetInfo);
out_net->name = ctx->id(ci->name.str(ctx) + "$nextnr_" + portId.str(ctx) + "_lut_through_net");
out_net->driver.cell = pt.get();
out_net->driver.port = ctx->id("O");
pt->ports.at(ctx->id("O")).net = out_net.get();
// New users of the original cell's port
std::vector<PortRef> new_users;
for (const auto &user : port.net->users) {
if (onlyNonLUTs && user.cell->type == ctx->id("ICESTORM_LC")) {
new_users.push_back(user);
continue;
}
// Rewrite pointer into net in user.
user.cell->ports[user.port].net = out_net.get();
// Add user to net.
PortRef pr;
pr.cell = user.cell;
pr.port = user.port;
out_net->users.push_back(pr);
}
// Add LUT to new users.
PortRef pr;
pr.cell = pt.get();
pr.port = ctx->id("I3");
new_users.push_back(pr);
pt->ports.at(ctx->id("I3")).net = port.net;
// Replace users of the original net.
port.net->users = new_users;
ctx->nets[out_net->name] = std::move(out_net);
return pt;
}
// Pack special functions
static void pack_special(Context *ctx)
{
log_info("Packing special functions..\n");
std::unordered_set<IdString> packed_cells;
std::vector<std::unique_ptr<CellInfo>> new_cells;
for (auto cell : sorted(ctx->cells)) {
CellInfo *ci = cell.second;
if (is_sb_lfosc(ctx, ci)) {
std::unique_ptr<CellInfo> packed =
create_ice_cell(ctx, ctx->id("ICESTORM_LFOSC"), ci->name.str(ctx) + "_OSC");
packed_cells.insert(ci->name);
replace_port(ci, ctx->id("CLKLFEN"), packed.get(), ctx->id("CLKLFEN"));
replace_port(ci, ctx->id("CLKLFPU"), packed.get(), ctx->id("CLKLFPU"));
if (/*bool_or_default(ci->attrs, ctx->id("ROUTE_THROUGH_FABRIC"))*/ true) { // FIXME
replace_port(ci, ctx->id("CLKLF"), packed.get(), ctx->id("CLKLF_FABRIC"));
} else {
replace_port(ci, ctx->id("CLKLF"), packed.get(), ctx->id("CLKLF"));
}
new_cells.push_back(std::move(packed));
} else if (is_sb_hfosc(ctx, ci)) {
std::unique_ptr<CellInfo> packed =
create_ice_cell(ctx, ctx->id("ICESTORM_HFOSC"), ci->name.str(ctx) + "_OSC");
packed_cells.insert(ci->name);
packed->params[ctx->id("CLKHF_DIV")] = str_or_default(ci->params, ctx->id("CLKHF_DIV"), "0b00");
replace_port(ci, ctx->id("CLKHFEN"), packed.get(), ctx->id("CLKHFEN"));
replace_port(ci, ctx->id("CLKHFPU"), packed.get(), ctx->id("CLKHFPU"));
if (/*bool_or_default(ci->attrs, ctx->id("ROUTE_THROUGH_FABRIC"))*/ true) { // FIXME
replace_port(ci, ctx->id("CLKHF"), packed.get(), ctx->id("CLKHF_FABRIC"));
} else {
replace_port(ci, ctx->id("CLKHF"), packed.get(), ctx->id("CLKHF"));
}
new_cells.push_back(std::move(packed));
} else if (is_sb_spram(ctx, ci)) {
std::unique_ptr<CellInfo> packed =
create_ice_cell(ctx, ctx->id("ICESTORM_SPRAM"), ci->name.str(ctx) + "_RAM");
packed_cells.insert(ci->name);
for (auto port : ci->ports) {
PortInfo &pi = port.second;
std::string newname = pi.name.str(ctx);
size_t bpos = newname.find('[');
if (bpos != std::string::npos) {
newname = newname.substr(0, bpos) + "_" + newname.substr(bpos + 1, (newname.size() - bpos) - 2);
}
replace_port(ci, ctx->id(pi.name.c_str(ctx)), packed.get(), ctx->id(newname));
}
new_cells.push_back(std::move(packed));
} else if (is_sb_mac16(ctx, ci)) {
std::unique_ptr<CellInfo> packed =
create_ice_cell(ctx, ctx->id("ICESTORM_DSP"), ci->name.str(ctx) + "_DSP");
packed_cells.insert(ci->name);
for (auto attr : ci->attrs)
packed->attrs[attr.first] = attr.second;
for (auto param : ci->params)
packed->params[param.first] = param.second;
for (auto port : ci->ports) {
PortInfo &pi = port.second;
std::string newname = pi.name.str(ctx);
size_t bpos = newname.find('[');
if (bpos != std::string::npos) {
newname = newname.substr(0, bpos) + "_" + newname.substr(bpos + 1, (newname.size() - bpos) - 2);
}
replace_port(ci, ctx->id(pi.name.c_str(ctx)), packed.get(), ctx->id(newname));
}
new_cells.push_back(std::move(packed));
} else if (is_sb_pll40(ctx, ci)) {
bool is_pad = is_sb_pll40_pad(ctx, ci);
bool is_core = !is_pad;
std::unique_ptr<CellInfo> packed =
create_ice_cell(ctx, ctx->id("ICESTORM_PLL"), ci->name.str(ctx) + "_PLL");
packed->attrs[ctx->id("TYPE")] = ci->type.str(ctx);
packed_cells.insert(ci->name);
for (auto attr : ci->attrs)
packed->attrs[attr.first] = attr.second;
for (auto param : ci->params)
packed->params[param.first] = param.second;
auto feedback_path = packed->params[ctx->id("FEEDBACK_PATH")];
packed->params[ctx->id("FEEDBACK_PATH")] =
feedback_path == "DELAY"
? "0"
: feedback_path == "SIMPLE" ? "1"
: feedback_path == "PHASE_AND_DELAY"
? "2"
: feedback_path == "EXTERNAL" ? "6" : feedback_path;
packed->params[ctx->id("PLLTYPE")] = std::to_string(sb_pll40_type(ctx, ci));
NetInfo *pad_packagepin_net = nullptr;
int pllout_a_used = 0;
int pllout_b_used = 0;
for (auto port : ci->ports) {
PortInfo &pi = port.second;
if (pi.name == ctx->id("PLLOUTCOREA"))
pllout_a_used++;
if (pi.name == ctx->id("PLLOUTCOREB"))
pllout_b_used++;
if (pi.name == ctx->id("PLLOUTCORE"))
pllout_a_used++;
if (pi.name == ctx->id("PLLOUTGLOBALA"))
pllout_a_used++;
if (pi.name == ctx->id("PLLOUTGLOBALB"))
pllout_b_used++;
if (pi.name == ctx->id("PLLOUTGLOBAL"))
pllout_a_used++;
}
if (pllout_a_used > 1)
log_error("PLL '%s' is using multiple ports mapping to PLLOUT_A output of the PLL\n",
ci->name.c_str(ctx));
if (pllout_b_used > 1)
log_error("PLL '%s' is using multiple ports mapping to PLLOUT_B output of the PLL\n",
ci->name.c_str(ctx));
for (auto port : ci->ports) {
PortInfo &pi = port.second;
std::string newname = pi.name.str(ctx);
size_t bpos = newname.find('[');
if (bpos != std::string::npos) {
newname = newname.substr(0, bpos) + "_" + newname.substr(bpos + 1, (newname.size() - bpos) - 2);
}
if (pi.name == ctx->id("PLLOUTCOREA"))
newname = "PLLOUT_A";
if (pi.name == ctx->id("PLLOUTCOREB"))
newname = "PLLOUT_B";
if (pi.name == ctx->id("PLLOUTCORE"))
newname = "PLLOUT_A";
if (pi.name == ctx->id("PLLOUTGLOBALA"))
newname = "PLLOUT_A";
if (pi.name == ctx->id("PLLOUTGLOBALB"))
newname = "PLLOUT_B";
if (pi.name == ctx->id("PLLOUTGLOBAL"))
newname = "PLLOUT_A";
if (pi.name == ctx->id("PLLOUTGLOBALA") || pi.name == ctx->id("PLLOUTGLOBALB") ||
pi.name == ctx->id("PLLOUTGLOBAL"))
log_warning("PLL '%s' is using port %s but implementation does not actually "
"use the global clock output of the PLL\n",
ci->name.c_str(ctx), pi.name.str(ctx).c_str());
if (pi.name == ctx->id("PACKAGEPIN")) {
if (!is_pad) {
log_error("PLL '%s' has a PACKAGEPIN but is not a PAD PLL\n", ci->name.c_str(ctx));
} else {
// We drop this port and instead place the PLL adequately below.
pad_packagepin_net = port.second.net;
NPNR_ASSERT(pad_packagepin_net != nullptr);
continue;
}
}
if (pi.name == ctx->id("REFERENCECLK")) {
if (!is_core)
log_error("PLL '%s' has a REFERENCECLK but is not a CORE PLL\n", ci->name.c_str(ctx));
}
if (packed->ports.count(ctx->id(newname)) == 0) {
if (ci->ports[pi.name].net == nullptr) {
log_warning("PLL '%s' has unknown unconnected port '%s' - ignoring\n", ci->name.c_str(ctx),
pi.name.c_str(ctx));
continue;
} else {
if (ctx->force) {
log_error("PLL '%s' has unknown connected port '%s'\n", ci->name.c_str(ctx),
pi.name.c_str(ctx));
} else {
log_warning("PLL '%s' has unknown connected port '%s' - ignoring\n", ci->name.c_str(ctx),
pi.name.c_str(ctx));
continue;
}
}
}
replace_port(ci, ctx->id(pi.name.c_str(ctx)), packed.get(), ctx->id(newname));
}
// If PLL is not constrained already, do that - we need this
// information to then constrain the LOCK LUT.
BelId pll_bel;
bool constrained = false;
if (packed->attrs.find(ctx->id("BEL")) == packed->attrs.end()) {
for (auto bel : ctx->getBels()) {
if (ctx->getBelType(bel) != id_ICESTORM_PLL)
continue;
if (ctx->isBelLocked(bel))
continue;
// A PAD PLL must have its' PACKAGEPIN on the SB_IO that's shared
// with PLLOUT_A.
if (is_pad) {
auto pll_sb_io_belpin = ctx->getIOBSharingPLLPin(bel, id_PLLOUT_A);
NPNR_ASSERT(pad_packagepin_net != nullptr);
auto pll_packagepin_driver = pad_packagepin_net->driver;
NPNR_ASSERT(pll_packagepin_driver.cell != nullptr);
if (pll_packagepin_driver.cell->type != ctx->id("SB_IO")) {
log_error("PLL '%s' has a PACKAGEPIN driven by "
"an %s, should be directly connected to an input SB_IO\n",
ci->name.c_str(ctx), pll_packagepin_driver.cell->type.c_str(ctx));
}
auto packagepin_cell = pll_packagepin_driver.cell;
auto packagepin_bel_name = packagepin_cell->attrs.find(ctx->id("BEL"));
if (packagepin_bel_name == packagepin_cell->attrs.end()) {
log_error("PLL '%s' PACKAGEPIN SB_IO '%s' is unconstrained\n", ci->name.c_str(ctx),
packagepin_cell->name.c_str(ctx));
}
auto packagepin_bel = ctx->getBelByName(ctx->id(packagepin_bel_name->second));
if (pll_sb_io_belpin.bel != packagepin_bel) {
log_error("PLL '%s' PACKAGEPIN is connected to pin %s, can only be pin %s\n",
ci->name.c_str(ctx), ctx->getBelPackagePin(packagepin_bel).c_str(),
ctx->getBelPackagePin(pll_sb_io_belpin.bel).c_str());
}
if (pad_packagepin_net->users.size() != 1) {
log_error("PLL '%s' clock input '%s' can only drive PLL\n", ci->name.c_str(ctx),
pad_packagepin_net->name.c_str(ctx));
}
// Set an attribute about this PLL's PAD SB_IO.
packed->attrs[ctx->id("BEL_PAD_INPUT")] = packagepin_bel_name->second;
// Remove the connection from the SB_IO to the PLL.
packagepin_cell->ports.erase(pll_packagepin_driver.port);
}
log_info(" constrained PLL '%s' to %s\n", packed->name.c_str(ctx),
ctx->getBelName(bel).c_str(ctx));
packed->attrs[ctx->id("BEL")] = ctx->getBelName(bel).str(ctx);
pll_bel = bel;
constrained = true;
break;
}
if (!constrained) {
log_error("Could not constrain PLL '%s' to any PLL Bel (too many PLLs?)\n",
packed->name.c_str(ctx));
}
} else {
pll_bel = ctx->getBelByName(ctx->id(packed->attrs[ctx->id("BEL")]));
if (ctx->getBelType(pll_bel) != id_ICESTORM_PLL)
log_error("PLL '%s' is constrained to BEL %s which isn't a ICESTORM_PLL BEL\n",
packed->name.c_str(ctx), ctx->getBelName(pll_bel).c_str(ctx));
if (ctx->isBelLocked(pll_bel))
log_error("PLL '%s' is constrained to locked BEL %s\n", packed->name.c_str(ctx),
ctx->getBelName(pll_bel).c_str(ctx));
log_info(" constrained PLL '%s' to %s\n", packed->name.c_str(ctx),
ctx->getBelName(pll_bel).c_str(ctx));
}
// Delete the original PACKAGEPIN net if needed.
if (pad_packagepin_net != nullptr) {
for (auto user : pad_packagepin_net->users) {
user.cell->ports.erase(user.port);
}
ctx->nets.erase(pad_packagepin_net->name);
pad_packagepin_net = nullptr;
}
// The LOCK signal on iCE40 PLLs goes through the neigh_op_bnl_1 wire.
// In practice, this means the LOCK signal can only directly reach LUT
// inputs.
// If we have a net connected to LOCK, make sure it only drives LUTs.
auto port = packed->ports[ctx->id("LOCK")];
if (port.net != nullptr) {
log_info(" PLL '%s' has LOCK output, need to pass all outputs via LUT\n", ci->name.c_str(ctx));
bool found_lut = false;
bool all_luts = true;
unsigned int lut_count = 0;
for (const auto &user : port.net->users) {
NPNR_ASSERT(user.cell != nullptr);
if (user.cell->type == ctx->id("ICESTORM_LC")) {
found_lut = true;
lut_count++;
} else {
all_luts = false;
}
}
if (found_lut && all_luts) {
// Every user is a LUT, carry on now.
} else if (found_lut && !all_luts && lut_count < 8) {
// Strategy: create a pass-through LUT, move all non-LUT users behind it.
log_info(" LUT strategy for %s: move non-LUT users to new LUT\n", port.name.c_str(ctx));
auto pt = spliceLUT(ctx, packed.get(), port.name, true);
new_cells.push_back(std::move(pt));
} else {
// Strategy: create a pass-through LUT, move every user behind it.
log_info(" LUT strategy for %s: move all users to new LUT\n", port.name.c_str(ctx));
auto pt = spliceLUT(ctx, packed.get(), port.name, false);
new_cells.push_back(std::move(pt));
}
// Find wire that will be driven by this port.
const auto pll_out_wire = ctx->getBelPinWire(pll_bel, port.name);
NPNR_ASSERT(pll_out_wire.index != -1);
// Now, constrain all LUTs on the output of the signal to be at
// the correct Bel relative to the PLL Bel.
int x = ctx->chip_info->wire_data[pll_out_wire.index].x;
int y = ctx->chip_info->wire_data[pll_out_wire.index].y;
int z = 0;
for (const auto &user : port.net->users) {
NPNR_ASSERT(user.cell != nullptr);
NPNR_ASSERT(user.cell->type == ctx->id("ICESTORM_LC"));
// TODO(q3k): handle when the Bel might be already the
// target of another constraint.
NPNR_ASSERT(z < 8);
auto target_bel = ctx->getBelByLocation(Loc(x, y, z++));
auto target_bel_name = ctx->getBelName(target_bel).str(ctx);
user.cell->attrs[ctx->id("BEL")] = target_bel_name;
log_info(" constrained '%s' to %s\n", user.cell->name.c_str(ctx), target_bel_name.c_str());
}
}
new_cells.push_back(std::move(packed));
}
}
for (auto pcell : packed_cells) {
ctx->cells.erase(pcell);
}
for (auto &ncell : new_cells) {
ctx->cells[ncell->name] = std::move(ncell);
}
}
// Main pack function
bool Arch::pack()
{
Context *ctx = getCtx();
try {
log_break();
pack_constants(ctx);
promote_globals(ctx);
pack_io(ctx);
pack_lut_lutffs(ctx);
pack_nonlut_ffs(ctx);
pack_carries(ctx);
pack_ram(ctx);
pack_special(ctx);
ctx->assignArchInfo();
constrain_chains(ctx);
ctx->assignArchInfo();
log_info("Checksum: 0x%08x\n", ctx->checksum());
return true;
} catch (log_execution_error_exception) {
return false;
}
}
NEXTPNR_NAMESPACE_END