502 lines
19 KiB
C++
502 lines
19 KiB
C++
/*
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* nextpnr -- Next Generation Place and Route
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*
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* Copyright (C) 2018 Clifford Wolf <clifford@clifford.at>
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* Copyright (C) 2018 David Shah <david@symbioticeda.com>
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*
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* Permission to use, copy, modify, and/or distribute this software for any
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* purpose with or without fee is hereby granted, provided that the above
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* copyright notice and this permission notice appear in all copies.
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*
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* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
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* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
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* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
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* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
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* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
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* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
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* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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*
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*/
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#include "pack.h"
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#include <algorithm>
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#include <unordered_set>
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#include "cells.h"
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#include "design_utils.h"
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#include "log.h"
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NEXTPNR_NAMESPACE_BEGIN
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// Pack LUTs and LUT-FF pairs
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static void pack_lut_lutffs(Context *ctx)
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{
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log_info("Packing LUT-FFs..\n");
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std::unordered_set<IdString> packed_cells;
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std::vector<CellInfo *> new_cells;
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for (auto cell : ctx->cells) {
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CellInfo *ci = cell.second;
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if (ctx->verbose)
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log_info("cell '%s' is of type '%s'\n", ci->name.c_str(ctx),
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ci->type.c_str(ctx));
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if (is_lut(ctx, ci)) {
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CellInfo *packed = create_ice_cell(ctx, "ICESTORM_LC",
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ci->name.str(ctx) + "_LC");
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std::copy(ci->attrs.begin(), ci->attrs.end(),
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std::inserter(packed->attrs, packed->attrs.begin()));
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packed_cells.insert(ci->name);
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new_cells.push_back(packed);
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if (ctx->verbose)
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log_info("packed cell %s into %s\n", ci->name.c_str(ctx),
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packed->name.c_str(ctx));
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// See if we can pack into a DFF
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// TODO: LUT cascade
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NetInfo *o = ci->ports.at(ctx->id("O")).net;
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CellInfo *dff = net_only_drives(ctx, o, is_ff, "D", true);
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auto lut_bel = ci->attrs.find(ctx->id("BEL"));
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bool packed_dff = false;
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if (dff) {
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if (ctx->verbose)
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log_info("found attached dff %s\n", dff->name.c_str(ctx));
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auto dff_bel = dff->attrs.find(ctx->id("BEL"));
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if (lut_bel != ci->attrs.end() && dff_bel != dff->attrs.end() &&
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lut_bel->second != dff_bel->second) {
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// Locations don't match, can't pack
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} else {
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lut_to_lc(ctx, ci, packed, false);
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dff_to_lc(ctx, dff, packed, false);
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ctx->nets.erase(o->name);
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if (dff_bel != dff->attrs.end())
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packed->attrs[ctx->id("BEL")] = dff_bel->second;
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packed_cells.insert(dff->name);
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if (ctx->verbose)
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log_info("packed cell %s into %s\n",
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dff->name.c_str(ctx), packed->name.c_str(ctx));
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packed_dff = true;
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}
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}
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if (!packed_dff) {
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lut_to_lc(ctx, ci, packed, true);
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}
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}
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}
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for (auto pcell : packed_cells) {
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ctx->cells.erase(pcell);
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}
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for (auto ncell : new_cells) {
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ctx->cells[ncell->name] = ncell;
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}
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}
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// Pack FFs not packed as LUTFFs
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static void pack_nonlut_ffs(Context *ctx)
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{
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log_info("Packing non-LUT FFs..\n");
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std::unordered_set<IdString> packed_cells;
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std::vector<CellInfo *> new_cells;
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for (auto cell : ctx->cells) {
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CellInfo *ci = cell.second;
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if (is_ff(ctx, ci)) {
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CellInfo *packed = create_ice_cell(ctx, "ICESTORM_LC",
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ci->name.str(ctx) + "_DFFLC");
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std::copy(ci->attrs.begin(), ci->attrs.end(),
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std::inserter(packed->attrs, packed->attrs.begin()));
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if (ctx->verbose)
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log_info("packed cell %s into %s\n", ci->name.c_str(ctx),
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packed->name.c_str(ctx));
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packed_cells.insert(ci->name);
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new_cells.push_back(packed);
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dff_to_lc(ctx, ci, packed, true);
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}
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}
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for (auto pcell : packed_cells) {
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ctx->cells.erase(pcell);
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}
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for (auto ncell : new_cells) {
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ctx->cells[ncell->name] = ncell;
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}
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}
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// Pack carry logic
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static void pack_carries(Context *ctx)
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{
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log_info("Packing carries..\n");
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std::unordered_set<IdString> packed_cells;
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for (auto cell : ctx->cells) {
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CellInfo *ci = cell.second;
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if (is_carry(ctx, ci)) {
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packed_cells.insert(cell.first);
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CellInfo *carry_ci_lc = net_only_drives(ctx, ci->ports.at("CI").net,
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is_lc, "I3", false);
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if (!ci->ports.at("I0").net)
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log_error("SB_CARRY '%s' has disconnected port I0\n",
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cell.first.c_str(ctx));
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if (!ci->ports.at("I1").net)
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log_error("SB_CARRY '%s' has disconnected port I1\n",
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cell.first.c_str(ctx));
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std::unordered_set<IdString> i0_matches, i1_matches;
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auto &i0_usrs = ci->ports.at("I0").net->users;
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auto &i1_usrs = ci->ports.at("I1").net->users;
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// Find logic cells connected to both I0 and I1
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for (auto usr : i0_usrs) {
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if (is_lc(ctx, usr.cell) && usr.port == ctx->id("I1"))
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i0_matches.insert(usr.cell->name);
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}
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for (auto usr : i1_usrs) {
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if (is_lc(ctx, usr.cell) && usr.port == ctx->id("I2"))
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i1_matches.insert(usr.cell->name);
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}
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std::set<IdString> carry_lcs;
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std::set_intersection(i0_matches.begin(), i0_matches.end(),
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i1_matches.begin(), i1_matches.end(),
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std::inserter(carry_lcs, carry_lcs.begin()));
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CellInfo *carry_lc = nullptr;
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if (carry_ci_lc) {
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if (carry_lcs.find(carry_ci_lc->name) == carry_lcs.end())
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log_error("SB_CARRY '%s' cannot be packed into any logic "
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"cell (I0 and I1 connections do not match I3 "
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"connection)\n",
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cell.first.c_str(ctx));
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carry_lc = carry_ci_lc;
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} else {
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if (carry_lcs.empty())
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log_error(
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"SB_CARRY '%s' cannot be packed into any logic "
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"cell (no logic cell connects to both I0 and I1)\n",
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cell.first.c_str(ctx));
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carry_lc = ctx->cells.at(*carry_lcs.begin());
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}
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carry_lc->attrs[ctx->id("CARRY_ENABLE")] = "1";
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replace_port(ci, "CI", carry_lc, "CIN");
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replace_port(ci, "CO", carry_lc, "COUT");
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i0_usrs.erase(std::remove_if(i0_usrs.begin(), i0_usrs.end(),
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[ci, ctx](const PortRef &pr) {
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return pr.cell == ci &&
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pr.port == ctx->id("I0");
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}));
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i1_usrs.erase(std::remove_if(i1_usrs.begin(), i1_usrs.end(),
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[ci, ctx](const PortRef &pr) {
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return pr.cell == ci &&
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pr.port == ctx->id("I1");
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}));
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}
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}
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for (auto pcell : packed_cells) {
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ctx->cells.erase(pcell);
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}
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}
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// "Pack" RAMs
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static void pack_ram(Context *ctx)
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{
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log_info("Packing RAMs..\n");
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std::unordered_set<IdString> packed_cells;
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std::vector<CellInfo *> new_cells;
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for (auto cell : ctx->cells) {
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CellInfo *ci = cell.second;
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if (is_ram(ctx, ci)) {
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CellInfo *packed = create_ice_cell(ctx, "ICESTORM_RAM",
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ci->name.str(ctx) + "_RAM");
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packed_cells.insert(ci->name);
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new_cells.push_back(packed);
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for (auto param : ci->params)
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packed->params[param.first] = param.second;
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packed->params["NEG_CLK_W"] =
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std::to_string(ci->type == ctx->id("SB_RAM40_4KNW") ||
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ci->type == ctx->id("SB_RAM40_4KNRNW"));
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packed->params["NEG_CLK_R"] =
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std::to_string(ci->type == ctx->id("SB_RAM40_4KNR") ||
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ci->type == ctx->id("SB_RAM40_4KNRNW"));
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packed->type = ctx->id("ICESTORM_RAM");
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for (auto port : ci->ports) {
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PortInfo &pi = port.second;
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std::string newname = pi.name;
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size_t bpos = newname.find('[');
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if (bpos != std::string::npos) {
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newname = newname.substr(0, bpos) + "_" +
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newname.substr(bpos + 1,
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(newname.size() - bpos) - 2);
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}
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replace_port(ci, pi.name, packed, newname);
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}
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}
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}
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for (auto pcell : packed_cells) {
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ctx->cells.erase(pcell);
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}
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for (auto ncell : new_cells) {
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ctx->cells[ncell->name] = ncell;
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}
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}
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// Merge a net into a constant net
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static void set_net_constant(const Context *ctx, NetInfo *orig,
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NetInfo *constnet, bool constval)
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{
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orig->driver.cell = nullptr;
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for (auto user : orig->users) {
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if (user.cell != nullptr) {
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CellInfo *uc = user.cell;
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if (ctx->verbose)
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log_info("%s user %s\n", orig->name.c_str(ctx),
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uc->name.c_str(ctx));
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if ((is_lut(ctx, uc) || is_lc(ctx, uc)) &&
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(user.port.str(ctx).at(0) == 'I') && !constval) {
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uc->ports[user.port].net = nullptr;
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} else {
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uc->ports[user.port].net = constnet;
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constnet->users.push_back(user);
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}
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}
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}
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orig->users.clear();
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}
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// Pack constants (simple implementation)
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static void pack_constants(Context *ctx)
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{
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log_info("Packing constants..\n");
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CellInfo *gnd_cell = create_ice_cell(ctx, "ICESTORM_LC", "$PACKER_GND");
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gnd_cell->params[ctx->id("LUT_INIT")] = "0";
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NetInfo *gnd_net = new NetInfo;
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gnd_net->name = "$PACKER_GND_NET";
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gnd_net->driver.cell = gnd_cell;
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gnd_net->driver.port = ctx->id("O");
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CellInfo *vcc_cell = create_ice_cell(ctx, "ICESTORM_LC", "$PACKER_VCC");
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vcc_cell->params[ctx->id("LUT_INIT")] = "1";
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NetInfo *vcc_net = new NetInfo;
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vcc_net->name = ctx->id("$PACKER_VCC_NET");
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vcc_net->driver.cell = vcc_cell;
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vcc_net->driver.port = ctx->id("O");
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std::vector<IdString> dead_nets;
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bool gnd_used = false, vcc_used = false;
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for (auto net : ctx->nets) {
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NetInfo *ni = net.second;
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if (ni->driver.cell != nullptr &&
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ni->driver.cell->type == ctx->id("GND")) {
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set_net_constant(ctx, ni, gnd_net, false);
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gnd_used = true;
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dead_nets.push_back(net.first);
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} else if (ni->driver.cell != nullptr &&
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ni->driver.cell->type == ctx->id("VCC")) {
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set_net_constant(ctx, ni, vcc_net, true);
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vcc_used = true;
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dead_nets.push_back(net.first);
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}
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}
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if (gnd_used) {
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ctx->cells[gnd_cell->name] = gnd_cell;
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ctx->nets[gnd_net->name] = gnd_net;
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}
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if (vcc_used) {
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ctx->cells[vcc_cell->name] = vcc_cell;
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ctx->nets[vcc_net->name] = vcc_net;
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}
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for (auto dn : dead_nets)
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ctx->nets.erase(dn);
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}
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static bool is_nextpnr_iob(Context *ctx, CellInfo *cell)
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{
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return cell->type == ctx->id("$nextpnr_ibuf") ||
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cell->type == ctx->id("$nextpnr_obuf") ||
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cell->type == ctx->id("$nextpnr_iobuf");
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}
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// Pack IO buffers
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static void pack_io(Context *ctx)
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{
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std::unordered_set<IdString> packed_cells;
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std::vector<CellInfo *> new_cells;
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log_info("Packing IOs..\n");
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for (auto cell : ctx->cells) {
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CellInfo *ci = cell.second;
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if (is_nextpnr_iob(ctx, ci)) {
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CellInfo *sb = nullptr;
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if (ci->type == ctx->id("$nextpnr_ibuf") ||
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ci->type == ctx->id("$nextpnr_iobuf")) {
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sb = net_only_drives(ctx, ci->ports.at("O").net, is_sb_io,
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"PACKAGE_PIN", true, ci);
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} else if (ci->type == ctx->id("$nextpnr_obuf")) {
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sb = net_only_drives(ctx, ci->ports.at("I").net, is_sb_io,
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"PACKAGE_PIN", true, ci);
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}
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if (sb != nullptr) {
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// Trivial case, SB_IO used. Just destroy the net and the
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// iobuf
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log_info("%s feeds SB_IO %s, removing %s %s.\n",
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ci->name.c_str(ctx), sb->name.c_str(ctx),
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ci->type.c_str(ctx), ci->name.c_str(ctx));
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NetInfo *net = sb->ports.at("PACKAGE_PIN").net;
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if (net != nullptr) {
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ctx->nets.erase(net->name);
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sb->ports.at("PACKAGE_PIN").net = nullptr;
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}
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} else {
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// Create a SB_IO buffer
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sb = create_ice_cell(ctx, "SB_IO",
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ci->name.str(ctx) + "$sb_io");
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nxio_to_sb(ctx, ci, sb);
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new_cells.push_back(sb);
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}
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packed_cells.insert(ci->name);
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std::copy(ci->attrs.begin(), ci->attrs.end(),
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std::inserter(sb->attrs, sb->attrs.begin()));
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}
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}
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for (auto pcell : packed_cells) {
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ctx->cells.erase(pcell);
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}
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for (auto ncell : new_cells) {
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ctx->cells[ncell->name] = ncell;
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}
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}
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static void insert_global(Context *ctx, NetInfo *net, bool is_reset,
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bool is_cen)
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{
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std::string glb_name = net->name.str(ctx) + std::string("_$glb_") +
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(is_reset ? "sr" : (is_cen ? "ce" : "clk"));
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CellInfo *gb = create_ice_cell(ctx, "SB_GB", "$gbuf_" + glb_name);
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gb->ports[ctx->id("USER_SIGNAL_TO_GLOBAL_BUFFER")].net = net;
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PortRef pr;
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pr.cell = gb;
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pr.port = ctx->id("USER_SIGNAL_TO_GLOBAL_BUFFER");
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net->users.push_back(pr);
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pr.cell = gb;
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pr.port = ctx->id("GLOBAL_BUFFER_OUTPUT");
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NetInfo *glbnet = new NetInfo();
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glbnet->name = ctx->id(glb_name);
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glbnet->driver = pr;
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ctx->nets[glbnet->name] = glbnet;
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gb->ports[ctx->id("GLOBAL_BUFFER_OUTPUT")].net = glbnet;
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std::vector<PortRef> keep_users;
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for (auto user : net->users) {
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if (is_clock_port(ctx, user) ||
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(is_reset && is_reset_port(ctx, user)) ||
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(is_cen && is_enable_port(ctx, user))) {
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user.cell->ports[user.port].net = glbnet;
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glbnet->users.push_back(user);
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} else {
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keep_users.push_back(user);
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}
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}
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net->users = keep_users;
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ctx->cells[gb->name] = gb;
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}
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// Simple global promoter (clock only)
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static void promote_globals(Context *ctx)
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{
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log_info("Promoting globals..\n");
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std::unordered_map<IdString, int> clock_count, reset_count, cen_count;
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for (auto net : ctx->nets) {
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NetInfo *ni = net.second;
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if (ni->driver.cell != nullptr && !is_global_net(ctx, ni)) {
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clock_count[net.first] = 0;
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reset_count[net.first] = 0;
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cen_count[net.first] = 0;
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for (auto user : ni->users) {
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if (is_clock_port(ctx, user))
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clock_count[net.first]++;
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if (is_reset_port(ctx, user))
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reset_count[net.first]++;
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if (is_enable_port(ctx, user))
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cen_count[net.first]++;
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}
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}
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}
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int prom_globals = 0, prom_resets = 0, prom_cens = 0;
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int gbs_available = 8;
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for (auto cell : ctx->cells)
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if (is_gbuf(ctx, cell.second))
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--gbs_available;
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while (prom_globals < gbs_available) {
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auto global_clock =
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std::max_element(clock_count.begin(), clock_count.end(),
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[](const std::pair<IdString, int> &a,
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const std::pair<IdString, int> &b) {
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return a.second < b.second;
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});
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auto global_reset =
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std::max_element(reset_count.begin(), reset_count.end(),
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[](const std::pair<IdString, int> &a,
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const std::pair<IdString, int> &b) {
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return a.second < b.second;
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});
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auto global_cen =
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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;
|
|
});
|
|
if (global_reset->second > global_clock->second && prom_resets < 4) {
|
|
NetInfo *rstnet = ctx->nets[global_reset->first];
|
|
insert_global(ctx, rstnet, true, false);
|
|
++prom_globals;
|
|
++prom_resets;
|
|
clock_count.erase(rstnet->name);
|
|
reset_count.erase(rstnet->name);
|
|
cen_count.erase(rstnet->name);
|
|
} else if (global_cen->second > global_clock->second && prom_cens < 4) {
|
|
NetInfo *cennet = ctx->nets[global_cen->first];
|
|
insert_global(ctx, cennet, false, true);
|
|
++prom_globals;
|
|
++prom_cens;
|
|
clock_count.erase(cennet->name);
|
|
reset_count.erase(cennet->name);
|
|
cen_count.erase(cennet->name);
|
|
} else if (global_clock->second != 0) {
|
|
NetInfo *clknet = ctx->nets[global_clock->first];
|
|
insert_global(ctx, clknet, false, false);
|
|
++prom_globals;
|
|
clock_count.erase(clknet->name);
|
|
reset_count.erase(clknet->name);
|
|
cen_count.erase(clknet->name);
|
|
} else {
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
// Main pack function
|
|
bool pack_design(Context *ctx)
|
|
{
|
|
log_break();
|
|
pack_constants(ctx);
|
|
promote_globals(ctx);
|
|
pack_io(ctx);
|
|
pack_lut_lutffs(ctx);
|
|
pack_nonlut_ffs(ctx);
|
|
pack_ram(ctx);
|
|
log_info("Checksum: 0x%08x\n", ctx->checksum());
|
|
return true;
|
|
}
|
|
|
|
NEXTPNR_NAMESPACE_END
|