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Merge branch 'redist_slack' into 'redist_slack'

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Redist slack

See merge request eddiehung/nextpnr!14
This commit is contained in:
Eddie Hung 2018-07-28 21:13:36 +00:00
commit b7bdc8db05
5 changed files with 32 additions and 62 deletions
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2
common/placer1.cc
View File

@ -237,7 +237,7 @@ class SAPlacer
ctx->shuffle(autoplaced);
assign_budget(ctx);
} else {
update_budget(ctx);
assign_budget(ctx, true /* quiet */);
}
// Recalculate total metric entirely to avoid rounding errors

2
common/router1.cc
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@ -616,7 +616,7 @@ bool router1(Context *ctx)
if (ctx->verbose || iterCnt == 1)
log_info("routing queue contains %d jobs.\n", int(jobQueue.size()));
update_budget(ctx);
assign_budget(ctx, true /* quiet */);
bool printNets = ctx->verbose && (jobQueue.size() < 10);

74
common/timing.cc
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@ -28,8 +28,8 @@ NEXTPNR_NAMESPACE_BEGIN
typedef std::list<const PortRef *> PortRefList;
static delay_t follow_net(Context *ctx, NetInfo *net, int path_length, delay_t slack, bool update,
delay_t &min_slack, PortRefList *current_path, PortRefList *crit_path);
static delay_t follow_net(Context *ctx, NetInfo *net, int path_length, delay_t slack, bool update, delay_t &min_slack,
PortRefList *current_path, PortRefList *crit_path);
// Follow a path, returning budget to annotate
static delay_t follow_user_port(Context *ctx, PortRef &user, int path_length, delay_t slack, bool update,
@ -68,8 +68,8 @@ static delay_t follow_user_port(Context *ctx, PortRef &user, int path_length, de
return value;
}
static delay_t follow_net(Context *ctx, NetInfo *net, int path_length, delay_t slack, bool update,
delay_t &min_slack, PortRefList *current_path, PortRefList *crit_path)
static delay_t follow_net(Context *ctx, NetInfo *net, int path_length, delay_t slack, bool update, delay_t &min_slack,
PortRefList *current_path, PortRefList *crit_path)
{
delay_t net_budget = slack / (path_length + 1);
for (unsigned i = 0; i < net->users.size(); ++i) {
@ -83,11 +83,11 @@ static delay_t follow_net(Context *ctx, NetInfo *net, int path_length, delay_t s
net_budget = budget;
pl = std::max(1, path_length);
}
net_budget = std::min(net_budget,
follow_user_port(ctx, usr, pl, slack - ctx->getNetinfoRouteDelay(net, i),
update, min_slack, current_path, crit_path));
auto delay = ctx->getNetinfoRouteDelay(net, i);
net_budget = std::min(
net_budget, follow_user_port(ctx, usr, pl, slack - delay, update, min_slack, current_path, crit_path));
if (update)
usr.budget = std::min(usr.budget, net_budget);
usr.budget = std::min(usr.budget, delay + net_budget);
if (crit_path)
current_path->pop_back();
}
@ -123,10 +123,13 @@ static delay_t walk_paths(Context *ctx, bool update, PortRefList *crit_path)
return min_slack;
}
void assign_budget(Context *ctx)
void assign_budget(Context *ctx, bool quiet)
{
log_break();
log_info("Annotating ports with timing budgets\n");
if (!quiet) {
log_break();
log_info("Annotating ports with timing budgets\n");
}
// Clear delays to a very high value first
delay_t default_slack = delay_t(1.0e12 / ctx->target_freq);
for (auto &net : ctx->nets) {
@ -137,42 +140,7 @@ void assign_budget(Context *ctx)
delay_t min_slack = walk_paths(ctx, true, nullptr);
for (auto &net : ctx->nets) {
for (auto &user : net.second->users) {
// Post-update check
if (ctx->user_freq && user.budget < 0)
log_warning("port %s.%s, connected to net '%s', has negative "
"timing budget of %fns\n",
user.cell->name.c_str(ctx), user.port.c_str(ctx), net.first.c_str(ctx),
ctx->getDelayNS(user.budget));
if (ctx->verbose)
log_info("port %s.%s, connected to net '%s', has "
"timing budget of %fns\n",
user.cell->name.c_str(ctx), user.port.c_str(ctx), net.first.c_str(ctx),
ctx->getDelayNS(user.budget));
}
}
// If user has not specified a frequency, adjust the target frequency dynamically
// TODO(eddieh): Tune these factors
if (!ctx->user_freq) {
if (min_slack < 0)
ctx->target_freq = 1e12 / (default_slack - 0.95 * min_slack);
else
ctx->target_freq = 1e12 / (default_slack - 1.2 * min_slack);
if (ctx->verbose)
log_info("minimum slack for this assign = %d, target Fmax for next update = %.2f MHz\n", min_slack,
ctx->target_freq / 1e6);
}
log_info("Checksum: 0x%08x\n", ctx->checksum());
}
void update_budget(Context *ctx)
{
delay_t min_slack = walk_paths(ctx, true, nullptr);
if (ctx->verbose) {
if (!quiet || ctx->verbose) {
for (auto &net : ctx->nets) {
for (auto &user : net.second->users) {
// Post-update check
@ -181,7 +149,7 @@ void update_budget(Context *ctx)
"timing budget of %fns\n",
user.cell->name.c_str(ctx), user.port.c_str(ctx), net.first.c_str(ctx),
ctx->getDelayNS(user.budget));
else
else if (ctx->verbose)
log_info("port %s.%s, connected to net '%s', has "
"timing budget of %fns\n",
user.cell->name.c_str(ctx), user.port.c_str(ctx), net.first.c_str(ctx),
@ -193,7 +161,6 @@ void update_budget(Context *ctx)
// If user has not specified a frequency, adjust the target frequency dynamically
// TODO(eddieh): Tune these factors
if (!ctx->user_freq) {
delay_t default_slack = delay_t(1.0e12 / ctx->target_freq);
if (min_slack < 0)
ctx->target_freq = 1e12 / (default_slack - 0.95 * min_slack);
else
@ -202,6 +169,9 @@ void update_budget(Context *ctx)
log_info("minimum slack for this assign = %d, target Fmax for next update = %.2f MHz\n", min_slack,
ctx->target_freq / 1e6);
}
if (!quiet)
log_info("Checksum: 0x%08x\n", ctx->checksum());
}
delay_t timing_analysis(Context *ctx, bool print_fmax, bool print_path)
@ -224,8 +194,10 @@ delay_t timing_analysis(Context *ctx, bool print_fmax, bool print_path)
auto net = port.net;
unsigned i = 0;
for (auto &usr : net->users)
if (&usr == sink) break;
else ++i;
if (&usr == sink)
break;
else
++i;
auto &driver = net->driver;
auto driver_cell = driver.cell;
delay_t comb_delay;

5
common/timing.h
View File

@ -24,11 +24,8 @@
NEXTPNR_NAMESPACE_BEGIN
// Assign "budget" values for all user ports in the design
void assign_budget(Context *ctx);
// Evenly redistribute the total path slack amongst all sinks on each path
void update_budget(Context *ctx);
void assign_budget(Context *ctx, bool quiet = false);
// Perform timing analysis and return the minimum path slack,
// optionally, print out the fmax and critical path

11
ice40/arch.cc
View File

@ -585,7 +585,7 @@ delay_t Arch::estimateDelay(WireId src, WireId dst) const
// }
// Estimate for output mux
for (const auto& bp : getWireBelPins(src)) {
for (const auto &bp : getWireBelPins(src)) {
if (bp.pin == PIN_O && getBelType(bp.bel) == TYPE_ICESTORM_LC) {
offset += 330;
break;
@ -593,8 +593,9 @@ delay_t Arch::estimateDelay(WireId src, WireId dst) const
}
// Estimate for input mux
for (const auto& bp : getWireBelPins(dst)) {
if ((bp.pin == PIN_I0 || bp.pin == PIN_I1 || bp.pin == PIN_I2 || bp.pin == PIN_I3) && getBelType(bp.bel) == TYPE_ICESTORM_LC) {
for (const auto &bp : getWireBelPins(dst)) {
if ((bp.pin == PIN_I0 || bp.pin == PIN_I1 || bp.pin == PIN_I2 || bp.pin == PIN_I3) &&
getBelType(bp.bel) == TYPE_ICESTORM_LC) {
offset += 260;
break;
}
@ -605,9 +606,9 @@ delay_t Arch::estimateDelay(WireId src, WireId dst) const
delay_t Arch::getBudgetOverride(NetInfo *net_info, int user_idx, delay_t budget) const
{
const auto& driver = net_info->driver;
const auto &driver = net_info->driver;
if (driver.port == id_cout) {
const auto& sink = net_info->users[user_idx];
const auto &sink = net_info->users[user_idx];
auto driver_loc = getBelLocation(driver.cell->bel);
auto sink_loc = getBelLocation(sink.cell->bel);
if (driver_loc.y == sink_loc.y)