nextpnr/common/kernel/timing_log.cc

/*
 *  nextpnr -- Next Generation Place and Route
 *
 *  Copyright (C) 2018  gatecat <gatecat@ds0.me>
 *  Copyright (C) 2018  Eddie Hung <eddieh@ece.ubc.ca>
 *  Copyright (C) 2023  rowanG077 <goemansrowan@gmail.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 "log.h"
#include "nextpnr.h"
#include "util.h"

NEXTPNR_NAMESPACE_BEGIN

static std::string clock_event_name(const Context *ctx, const ClockEvent &e, int field_width = 0)
{
    std::string value;
    if (e.clock == IdString() || e.clock == ctx->id("$async$"))
        value = std::string("<async>");
    else
        value = (e.edge == FALLING_EDGE ? std::string("negedge ") : std::string("posedge ")) + e.clock.str(ctx);
    if (int(value.length()) < field_width)
        value.insert(value.length(), field_width - int(value.length()), ' ');
    return value;
};

static void log_crit_paths(const Context *ctx, TimingResult &result)
{
    static auto print_net_source = [ctx](const NetInfo *net) {
        // Check if this net is annotated with a source list
        auto sources = net->attrs.find(ctx->id("src"));
        if (sources == net->attrs.end()) {
            // No sources for this net, can't print anything
            return;
        }

        // Sources are separated by pipe characters.
        // There is no guaranteed ordering on sources, so we just print all
        auto sourcelist = sources->second.as_string();
        std::vector<std::string> source_entries;
        size_t current = 0, prev = 0;
        while ((current = sourcelist.find("|", prev)) != std::string::npos) {
            source_entries.emplace_back(sourcelist.substr(prev, current - prev));
            prev = current + 1;
        }
        // Ensure we emplace the final entry
        source_entries.emplace_back(sourcelist.substr(prev, current - prev));

        // Iterate and print our source list at the correct indentation level
        log_info("               Defined in:\n");
        for (auto entry : source_entries) {
            log_info("                 %s\n", entry.c_str());
        }
    };

    // A helper function for reporting one critical path
    auto print_path_report = [ctx](const CriticalPath &path) {
        delay_t total = 0, logic_total = 0, route_total = 0;

        log_info("curr total\n");
        for (const auto &segment : path.segments) {

            total += segment.delay;

            if (segment.type == CriticalPath::Segment::Type::CLK_TO_Q ||
                segment.type == CriticalPath::Segment::Type::SOURCE ||
                segment.type == CriticalPath::Segment::Type::LOGIC ||
                segment.type == CriticalPath::Segment::Type::SETUP) {
                logic_total += segment.delay;

                const std::string type_name = (segment.type == CriticalPath::Segment::Type::SETUP) ? "Setup" : "Source";

                log_info("%4.1f %4.1f  %s %s.%s\n", ctx->getDelayNS(segment.delay), ctx->getDelayNS(total),
                         type_name.c_str(), segment.to.first.c_str(ctx), segment.to.second.c_str(ctx));
            } else if (segment.type == CriticalPath::Segment::Type::ROUTING) {
                route_total += segment.delay;

                const auto &driver = ctx->cells.at(segment.from.first);
                const auto &sink = ctx->cells.at(segment.to.first);

                auto driver_loc = ctx->getBelLocation(driver->bel);
                auto sink_loc = ctx->getBelLocation(sink->bel);

                log_info("%4.1f %4.1f    Net %s (%d,%d) -> (%d,%d)\n", ctx->getDelayNS(segment.delay),
                         ctx->getDelayNS(total), segment.net.c_str(ctx), driver_loc.x, driver_loc.y, sink_loc.x,
                         sink_loc.y);
                log_info("               Sink %s.%s\n", segment.to.first.c_str(ctx), segment.to.second.c_str(ctx));

                const NetInfo *net = ctx->nets.at(segment.net).get();

                if (ctx->verbose) {

                    PortRef sink_ref;
                    sink_ref.cell = sink.get();
                    sink_ref.port = segment.to.second;

                    auto driver_wire = ctx->getNetinfoSourceWire(net);
                    auto sink_wire = ctx->getNetinfoSinkWire(net, sink_ref, 0);
                    log_info("                 prediction: %f ns estimate: %f ns\n",
                             ctx->getDelayNS(ctx->predictArcDelay(net, sink_ref)),
                             ctx->getDelayNS(ctx->estimateDelay(driver_wire, sink_wire)));
                    auto cursor = sink_wire;
                    delay_t delay;
                    while (driver_wire != cursor) {
#ifdef ARCH_ECP5
                        if (net->is_global)
                            break;
#endif
                        auto it = net->wires.find(cursor);
                        assert(it != net->wires.end());
                        auto pip = it->second.pip;
                        NPNR_ASSERT(pip != PipId());
                        delay = ctx->getPipDelay(pip).maxDelay();
                        log_info("                 %1.3f %s\n", ctx->getDelayNS(delay), ctx->nameOfPip(pip));
                        cursor = ctx->getPipSrcWire(pip);
                    }
                }

                if (!ctx->disable_critical_path_source_print) {
                    print_net_source(net);
                }
            }
        }
        log_info("%.1f ns logic, %.1f ns routing\n", ctx->getDelayNS(logic_total), ctx->getDelayNS(route_total));
    };

    // Single domain paths
    for (auto &clock : result.clock_paths) {
        log_break();
        std::string start =
                clock.second.clock_pair.start.edge == FALLING_EDGE ? std::string("negedge") : std::string("posedge");
        std::string end =
                clock.second.clock_pair.end.edge == FALLING_EDGE ? std::string("negedge") : std::string("posedge");
        log_info("Critical path report for clock '%s' (%s -> %s):\n", clock.first.c_str(ctx), start.c_str(),
                 end.c_str());
        auto &report = clock.second;
        print_path_report(report);
    }

    // Cross-domain paths
    for (auto &report : result.xclock_paths) {
        log_break();
        std::string start = clock_event_name(ctx, report.clock_pair.start);
        std::string end = clock_event_name(ctx, report.clock_pair.end);
        log_info("Critical path report for cross-domain path '%s' -> '%s':\n", start.c_str(), end.c_str());
        print_path_report(report);
    }
};

static void log_fmax(Context *ctx, TimingResult &result, bool warn_on_failure)
{
    log_break();

    if (result.clock_paths.empty() && result.clock_paths.empty()) {
        log_info("No Fmax available; no interior timing paths found in design.\n");
        return;
    }

    unsigned max_width = 0;
    for (auto &clock : result.clock_paths)
        max_width = std::max<unsigned>(max_width, clock.first.str(ctx).size());

    for (auto &clock : result.clock_paths) {
        const auto &clock_name = clock.first.str(ctx);
        const int width = max_width - clock_name.size();

        float fmax = result.clock_fmax[clock.first].achieved;
        float target = result.clock_fmax[clock.first].constraint;
        bool passed = target < fmax;

        if (!warn_on_failure || passed)
            log_info("Max frequency for clock %*s'%s': %.02f MHz (%s at %.02f MHz)\n", width, "", clock_name.c_str(),
                     fmax, passed ? "PASS" : "FAIL", target);
        else if (bool_or_default(ctx->settings, ctx->id("timing/allowFail"), false))
            log_warning("Max frequency for clock %*s'%s': %.02f MHz (%s at %.02f MHz)\n", width, "", clock_name.c_str(),
                        fmax, passed ? "PASS" : "FAIL", target);
        else
            log_nonfatal_error("Max frequency for clock %*s'%s': %.02f MHz (%s at %.02f MHz)\n", width, "",
                               clock_name.c_str(), fmax, passed ? "PASS" : "FAIL", target);
    }
    log_break();

    // Clock to clock delays for xpaths
    dict<ClockPair, delay_t> xclock_delays;
    for (auto &report : result.xclock_paths) {
        const auto &clock1_name = report.clock_pair.start.clock;
        const auto &clock2_name = report.clock_pair.end.clock;

        const auto key = std::make_pair(clock1_name, clock2_name);
        if (result.clock_delays.count(key)) {
            xclock_delays[report.clock_pair] = result.clock_delays.at(key);
        }
    }

    unsigned max_width_xca = 0;
    unsigned max_width_xcb = 0;
    for (auto &report : result.xclock_paths) {
        max_width_xca = std::max((unsigned)clock_event_name(ctx, report.clock_pair.start).length(), max_width_xca);
        max_width_xcb = std::max((unsigned)clock_event_name(ctx, report.clock_pair.end).length(), max_width_xcb);
    }

    // Check and report xpath delays for related clocks
    if (!result.xclock_paths.empty()) {
        for (auto &report : result.xclock_paths) {
            const auto &clock_a = report.clock_pair.start.clock;
            const auto &clock_b = report.clock_pair.end.clock;

            const auto key = std::make_pair(clock_a, clock_b);
            if (!result.clock_delays.count(key)) {
                continue;
            }

            delay_t path_delay = 0;
            for (const auto &segment : report.segments) {
                path_delay += segment.delay;
            }

            // Compensate path delay for clock-to-clock delay. If the
            // result is negative then only the latter matters. Otherwise
            // the compensated path delay is taken.
            auto clock_delay = result.clock_delays.at(key);
            path_delay -= clock_delay;

            float fmax = std::numeric_limits<float>::infinity();
            if (path_delay < 0) {
                fmax = 1e3f / ctx->getDelayNS(clock_delay);
            } else if (path_delay > 0) {
                fmax = 1e3f / ctx->getDelayNS(path_delay);
            }

            // Both clocks are related so they should have the same
            // frequency. However, they may get different constraints from
            // user input. In case of only one constraint preset take it,
            // otherwise get the worst case (min.)
            float target;
            auto &clock_fmax = result.clock_fmax;
            if (clock_fmax.count(clock_a) && !clock_fmax.count(clock_b)) {
                target = clock_fmax.at(clock_a).constraint;
            } else if (!clock_fmax.count(clock_a) && clock_fmax.count(clock_b)) {
                target = clock_fmax.at(clock_b).constraint;
            } else {
                target = std::min(clock_fmax.at(clock_a).constraint, clock_fmax.at(clock_b).constraint);
            }

            bool passed = target < fmax;

            auto ev_a = clock_event_name(ctx, report.clock_pair.start, max_width_xca);
            auto ev_b = clock_event_name(ctx, report.clock_pair.end, max_width_xcb);

            if (!warn_on_failure || passed)
                log_info("Max frequency for %s -> %s: %.02f MHz (%s at %.02f MHz)\n", ev_a.c_str(), ev_b.c_str(), fmax,
                         passed ? "PASS" : "FAIL", target);
            else if (bool_or_default(ctx->settings, ctx->id("timing/allowFail"), false) ||
                     bool_or_default(ctx->settings, ctx->id("timing/ignoreRelClk"), false))
                log_warning("Max frequency for  %s -> %s: %.02f MHz (%s at %.02f MHz)\n", ev_a.c_str(), ev_b.c_str(),
                            fmax, passed ? "PASS" : "FAIL", target);
            else
                log_nonfatal_error("Max frequency for %s -> %s: %.02f MHz (%s at %.02f MHz)\n", ev_a.c_str(),
                                   ev_b.c_str(), fmax, passed ? "PASS" : "FAIL", target);
        }
        log_break();
    }

    // Report clock delays for xpaths
    if (!result.clock_delays.empty()) {
        for (auto &pair : xclock_delays) {
            auto ev_a = clock_event_name(ctx, pair.first.start, max_width_xca);
            auto ev_b = clock_event_name(ctx, pair.first.end, max_width_xcb);

            delay_t delay = pair.second;
            if (pair.first.start.edge != pair.first.end.edge) {
                delay /= 2;
            }

            log_info("Clock to clock delay %s -> %s: %0.02f ns\n", ev_a.c_str(), ev_b.c_str(), ctx->getDelayNS(delay));
        }

        log_break();
    }

    for (auto &eclock : result.empty_paths) {
        if (eclock != IdString())
            log_info("Clock '%s' has no interior paths\n", eclock.c_str(ctx));
    }
    log_break();

    int start_field_width = 0, end_field_width = 0;
    for (auto &report : result.xclock_paths) {
        start_field_width = std::max((int)clock_event_name(ctx, report.clock_pair.start).length(), start_field_width);
        end_field_width = std::max((int)clock_event_name(ctx, report.clock_pair.end).length(), end_field_width);
    }

    for (auto &report : result.xclock_paths) {
        const ClockEvent &a = report.clock_pair.start;
        const ClockEvent &b = report.clock_pair.end;
        delay_t path_delay = 0;
        for (const auto &segment : report.segments) {
            path_delay += segment.delay;
        }
        auto ev_a = clock_event_name(ctx, a, start_field_width), ev_b = clock_event_name(ctx, b, end_field_width);
        log_info("Max delay %s -> %s: %0.02f ns\n", ev_a.c_str(), ev_b.c_str(), ctx->getDelayNS(path_delay));
    }
    log_break();
}

static void log_histogram(Context *ctx, TimingResult &result)
{
    unsigned num_bins = 20;
    unsigned bar_width = 60;

    int min_slack = std::numeric_limits<int>::max();
    int max_slack = std::numeric_limits<int>::min();

    for (const auto &i : result.slack_histogram) {
        if (i.first < min_slack)
            min_slack = i.first;
        if (i.first > max_slack)
            max_slack = i.first;
    }

    auto bin_size = std::max<unsigned>(1, ceil((max_slack - min_slack + 1) / float(num_bins)));
    std::vector<unsigned> bins(num_bins);
    unsigned max_freq = 0;
    for (const auto &i : result.slack_histogram) {
        int bin_idx = int((i.first - min_slack) / bin_size);
        if (bin_idx < 0)
            bin_idx = 0;
        else if (bin_idx >= int(num_bins))
            bin_idx = num_bins - 1;
        auto &bin = bins.at(bin_idx);
        bin += i.second;
        max_freq = std::max(max_freq, bin);
    }
    bar_width = std::min(bar_width, max_freq);

    log_break();
    log_info("Slack histogram:\n");
    log_info(" legend: * represents %d endpoint(s)\n", max_freq / bar_width);
    log_info("         + represents [1,%d) endpoint(s)\n", max_freq / bar_width);
    for (unsigned i = 0; i < num_bins; ++i)
        log_info("[%6d, %6d) |%s%c\n", min_slack + bin_size * i, min_slack + bin_size * (i + 1),
                 std::string(bins[i] * bar_width / max_freq, '*').c_str(),
                 (bins[i] * bar_width) % max_freq > 0 ? '+' : ' ');
}

void Context::log_timing_results(TimingResult &result, bool print_histogram, bool print_fmax, bool print_path,
                                 bool warn_on_failure)
{
    if (print_path)
        log_crit_paths(this, result);

    if (print_fmax)
        log_fmax(this, result, warn_on_failure);

    if (print_histogram && !timing_result.slack_histogram.empty())
        log_histogram(this, result);
}

NEXTPNR_NAMESPACE_END