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placer1: Add (currently-unused) option for fanout threshold for timing cost calc

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Signed-off-by: David Shah <davey1576@gmail.com>
This commit is contained in:
David Shah 2018-12-30 10:53:13 +01:00 committed by David Shah
parent bd0a33022b
commit 9cd5980d35
2 changed files with 5 additions and 3 deletions
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5
common/placer1.cc
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@ -729,7 +729,7 @@ class SAPlacer
if (ignore_net(ni))
continue;
net_bounds[ni->udata] = get_net_bounds(ni);
if (ctx->timing_driven)
if (ctx->timing_driven && int(ni->users.size()) < cfg.timingFanoutThresh)
for (size_t i = 0; i < ni->users.size(); i++)
net_arc_tcost[ni->udata][i] = get_timing_cost(ni, i);
}
@ -806,7 +806,7 @@ class SAPlacer
mc.bounds_changed_nets.push_back(pn->udata);
mc.already_bounds_changed[pn->udata] = true;
}
if (ctx->timing_driven) {
if (ctx->timing_driven && int(pn->users.size()) < cfg.timingFanoutThresh) {
// Output ports - all arcs change timing
if (port.second.type == PORT_OUT) {
int cc;
@ -913,6 +913,7 @@ Placer1Cfg::Placer1Cfg(Context *ctx) : Settings(ctx)
minBelsForGridPick = get<int>("placer1/minBelsForGridPick", 64);
budgetBased = get<bool>("placer1/budgetBased", false);
startTemp = get<float>("placer1/startTemp", 1);
timingFanoutThresh = std::numeric_limits<int>::max();
}
bool placer1(Context *ctx, Placer1Cfg cfg)

1
common/placer1.h
View File

@ -31,6 +31,7 @@ struct Placer1Cfg : public Settings
int minBelsForGridPick;
bool budgetBased;
float startTemp;
int timingFanoutThresh;
};
extern bool placer1(Context *ctx, Placer1Cfg cfg);