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Merge pull request #40 from eddiehung/fix_budget_overrides

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Fix budget overrides
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David Shah 2018-08-06 21:25:30 +02:00 committed by GitHub
commit 88d2c49440
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8 changed files with 46 additions and 24 deletions
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29
common/timing.cc
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@ -2,6 +2,7 @@
* nextpnr -- Next Generation Place and Route
*
* Copyright (C) 2018 David Shah <david@symbioticeda.com>
* Copyright (C) 2018 Eddie Hung <eddieh@ece.ubc.ca>
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
@ -48,22 +49,26 @@ struct Timing
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) {
auto delay = net_delays ? ctx->getNetinfoRouteDelay(net, usr) : delay_t();
if (crit_path)
current_path.push_back(&usr);
// If budget override is less than existing budget, then do not increment
// path length
int pl = path_length + 1;
auto budget = ctx->getBudgetOverride(net, usr, net_budget);
if (budget < net_budget) {
net_budget = budget;
pl = std::max(1, path_length);
// If budget override exists, use that value and do not increment path_length
auto budget = default_budget;
if (ctx->getBudgetOverride(net, usr, budget)) {
if (update)
usr.budget = std::min(usr.budget, budget);
budget = follow_user_port(usr, path_length, slack - budget);
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)
current_path.pop_back();
}

4
docs/archapi.md
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@ -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.
### 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
------------

2
ecp5/arch.cc
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@ -422,7 +422,7 @@ delay_t Arch::predictDelay(const NetInfo *net_info, const PortRef &sink) const
return 200 * (abs(driver_loc.x - sink_loc.x) + abs(driver_loc.y - sink_loc.y));
}
delay_t Arch::getBudgetOverride(const NetInfo *net_info, const PortRef &sink, delay_t budget) const { return budget; }
bool Arch::getBudgetOverride(const NetInfo *net_info, const PortRef &sink, delay_t &budget) const { return false; }
// -----------------------------------------------------------------------

2
ecp5/arch.h
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@ -805,7 +805,7 @@ struct Arch : BaseCtx
delay_t getRipupDelayPenalty() const { return 200; }
float getDelayNS(delay_t v) const { return v * 0.001; }
uint32_t getDelayChecksum(delay_t v) const { return v; }
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;
// -------------------------------------------------

2
generic/arch.cc
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@ -408,7 +408,7 @@ delay_t Arch::predictDelay(const NetInfo *net_info, const PortRef &sink) const
return (dx + dy) * grid_distance_to_delay;
}
delay_t Arch::getBudgetOverride(const NetInfo *net_info, const PortRef &sink, delay_t budget) const { return budget; }
bool Arch::getBudgetOverride(const NetInfo *net_info, const PortRef &sink, delay_t &budget) const { return false; }
// ---------------------------------------------------------------

2
generic/arch.h
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@ -200,7 +200,7 @@ struct Arch : BaseCtx
delay_t getRipupDelayPenalty() const { return 1.0; }
float getDelayNS(delay_t v) const { return v; }
uint32_t getDelayChecksum(delay_t v) const { return 0; }
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;
bool pack() { return true; }
bool place();

27
ice40/arch.cc
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@ -637,17 +637,34 @@ std::vector<GroupId> Arch::getGroupGroups(GroupId group) const
// -----------------------------------------------------------------------
delay_t 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;
if (driver.port == id_cout) {
if (driver.port == id_cout && sink.port == id_cin) {
auto driver_loc = getBelLocation(driver.cell->bel);
auto sink_loc = getBelLocation(sink.cell->bel);
if (driver_loc.y == sink_loc.y)
return 0;
return 250;
budget = 0;
else switch (args.type) {
#ifndef ICE40_HX1K_ONLY
case ArchArgs::HX8K:
#endif
case ArchArgs::HX1K:
budget = 190; break;
#ifndef ICE40_HX1K_ONLY
case ArchArgs::LP384:
case ArchArgs::LP1K:
case ArchArgs::LP8K:
budget = 290; break;
case ArchArgs::UP5K:
budget = 560; break;
#endif
default:
log_error("Unsupported iCE40 chip type.\n");
}
return true;
}
return budget;
return false;
}
// -----------------------------------------------------------------------

2
ice40/arch.h
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@ -766,7 +766,7 @@ struct Arch : BaseCtx
delay_t getRipupDelayPenalty() const { return 200; }
float getDelayNS(delay_t v) const { return v * 0.001; }
uint32_t getDelayChecksum(delay_t v) const { return v; }
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;
// -------------------------------------------------