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Merge branch 'fix_budget_overrides' into assign_budget_speedup

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Conflicts:
	common/timing.cc
This commit is contained in:
Eddie Hung 2018-08-06 09:02:49 -07:00
commit 266b761f41
3 changed files with 25 additions and 28 deletions
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47
common/timing.cc
View File

@ -57,22 +57,26 @@ struct Timing
delay_t follow_net(NetInfo *net, int path_length, delay_t slack) delay_t follow_net(NetInfo *net, int path_length, delay_t slack)
{ {
delay_t net_budget = slack / (path_length + 1); const delay_t default_budget = slack / (path_length + 1);
delay_t net_budget = default_budget;
for (auto &usr : net->users) { for (auto &usr : net->users) {
auto delay = net_delays ? ctx->getNetinfoRouteDelay(net, usr) : delay_t();
if (crit_path) if (crit_path)
current_path.push_back(&usr); current_path.push_back(&usr);
// If budget override is less than existing budget, then do not increment // If budget override exists, use that value and do not increment path_length
// path length auto budget = default_budget;
int pl = path_length + 1; if (ctx->getBudgetOverride(net, usr, budget)) {
auto budget = net_budget; if (update)
if (ctx->getBudgetOverride(net, usr, budget) && budget < net_budget) { usr.budget = std::min(usr.budget, budget);
net_budget = budget; budget = follow_user_port(usr, path_length, slack - budget);
pl = std::max(1, path_length); net_budget = std::min(net_budget, budget);
}
else {
budget = follow_user_port(usr, path_length + 1, slack - delay);
net_budget = std::min(net_budget, budget);
if (update)
usr.budget = std::min(usr.budget, delay + budget);
} }
auto delay = net_delays ? ctx->getNetinfoRouteDelay(net, usr) : delay_t();
net_budget = std::min(net_budget, follow_user_port(usr, pl, slack - delay));
if (update)
usr.budget = std::min(usr.budget, delay + net_budget);
if (crit_path) if (crit_path)
current_path.pop_back(); current_path.pop_back();
} }
@ -222,8 +226,7 @@ struct Timing
if (ctx->getPortClock(usr.cell, usr.port) != IdString()) { if (ctx->getPortClock(usr.cell, usr.port) != IdString()) {
} else { } else {
auto net_delay = ctx->getNetinfoRouteDelay(net, usr); auto net_delay = ctx->getNetinfoRouteDelay(net, usr);
delay_t budget; auto budget_override = ctx->getBudgetOverride(net, usr, net_delay);
auto budget_override = ctx->getBudgetOverride(net, usr, budget);
auto usr_arrival = net_arrival + net_delay; auto usr_arrival = net_arrival + net_delay;
// Follow outputs of the user // Follow outputs of the user
for (auto port : usr.cell->ports) { for (auto port : usr.cell->ports) {
@ -252,15 +255,12 @@ struct Timing
auto& net_min_remaining_budget = nd.min_remaining_budget; auto& net_min_remaining_budget = nd.min_remaining_budget;
for (auto &usr : net->users) { for (auto &usr : net->users) {
const auto net_delay = ctx->getNetinfoRouteDelay(net, usr); const auto net_delay = ctx->getNetinfoRouteDelay(net, usr);
auto budget_override = ctx->getBudgetOverride(net, usr, usr.budget); auto budget_override = ctx->getBudgetOverride(net, usr, net_delay);
if (ctx->getPortClock(usr.cell, usr.port) != IdString()) { if (ctx->getPortClock(usr.cell, usr.port) != IdString()) {
const auto net_arrival = nd.max_arrival; const auto net_arrival = nd.max_arrival;
auto path_budget = clk_period - (net_arrival + net_delay); auto path_budget = clk_period - (net_arrival + net_delay);
auto budget_share = path_budget / net_length_plus_one; auto budget_share = budget_override ? 0 : path_budget / net_length_plus_one;
if (budget_override) usr.budget = std::min(usr.budget, net_delay + budget_share);
budget_share = 0;
else
usr.budget = std::min(usr.budget, net_delay + budget_share);
net_min_remaining_budget = std::min(net_min_remaining_budget, path_budget - budget_share); net_min_remaining_budget = std::min(net_min_remaining_budget, path_budget - budget_share);
min_slack = std::min(min_slack, path_budget); min_slack = std::min(min_slack, path_budget);
@ -277,11 +277,8 @@ struct Timing
bool is_path = ctx->getCellDelay(usr.cell, usr.port, port.first, comb_delay); bool is_path = ctx->getCellDelay(usr.cell, usr.port, port.first, comb_delay);
if (is_path) { if (is_path) {
auto path_budget = net_data.at(port.second.net).min_remaining_budget; auto path_budget = net_data.at(port.second.net).min_remaining_budget;
auto budget_share = path_budget / net_length_plus_one; auto budget_share = budget_override ? 0 : path_budget / net_length_plus_one;
if (budget_override) usr.budget = std::min(usr.budget, net_delay + budget_share);
budget_share = 0;
else
usr.budget = std::min(usr.budget, net_delay + budget_share);
net_min_remaining_budget = std::min(net_min_remaining_budget, path_budget - budget_share); net_min_remaining_budget = std::min(net_min_remaining_budget, path_budget - budget_share);
} }
} }

4
docs/archapi.md
View File

@ -402,9 +402,9 @@ Convert an `delay_t` to an actual real-world delay in nanoseconds.
Convert a `delay_t` to an integer for checksum calculations. Convert a `delay_t` to an integer for checksum calculations.
### delay\_t getBudgetOverride(const NetInfo \*net\_info, const PortRef &sink, delay\_t budget) const ### bool getBudgetOverride(const NetInfo \*net\_info, const PortRef &sink, delay\_t &budget) const
Overwrite or modify the timing budget for a given arc. Returns the new budget. Overwrite or modify (in-place) the timing budget for a given arc. Returns a bool to indicate whether this was done.
Flow Methods Flow Methods
------------ ------------

2
ice40/arch.cc
View File

@ -640,7 +640,7 @@ std::vector<GroupId> Arch::getGroupGroups(GroupId group) const
bool Arch::getBudgetOverride(const NetInfo *net_info, const PortRef &sink, delay_t &budget) const bool Arch::getBudgetOverride(const NetInfo *net_info, const PortRef &sink, delay_t &budget) const
{ {
const auto &driver = net_info->driver; const auto &driver = net_info->driver;
if (driver.port == id_cout) { if (driver.port == id_cout && sink.port == id_cin) {
auto driver_loc = getBelLocation(driver.cell->bel); auto driver_loc = getBelLocation(driver.cell->bel);
auto sink_loc = getBelLocation(sink.cell->bel); auto sink_loc = getBelLocation(sink.cell->bel);
if (driver_loc.y == sink_loc.y) if (driver_loc.y == sink_loc.y)