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static: Fix NaN on a big xilinx design 

Signed-off-by: gatecat <gatecat@ds0.me>
This commit is contained in:
gatecat 2026-03-04 09:45:43 +01:00
parent dd4d3056eb
commit fcaafbaa08
3 changed files with 15 additions and 4 deletions
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7
common/place/placer_static.cc
View File

@ -343,7 +343,7 @@ class StaticPlacer
auto &nd = nets.back();
nd.ni = ni;
nd.skip = (ni->driver.cell == nullptr); // (or global buffer?)
nd.skip = (ni->driver.cell == nullptr || cfg.glbBufTypes.count(ni->driver.cell->type));
nd.ports.resize(ni->users.capacity() + 1); // +1 for the driver
nd.ports.back().ref = ni->driver;
for (auto usr : ni->users.enumerate()) {
@ -798,6 +798,7 @@ class StaticPlacer
port.max_exp.at(axis) = std::exp(emax);
net.max_exp.at(axis) += port.max_exp.at(axis);
net.x_max_exp.at(axis) += loc.at(axis) * port.max_exp.at(axis);
NPNR_ASSERT(std::isfinite(net.x_max_exp.at(axis)));
} else {
port.max_exp.at(axis) = PlacerPort::invalid;
}
@ -831,12 +832,14 @@ class StaticPlacer
d_min = (min_sum * (pd.min_exp.at(axis) * (1.0f - wl_coeff.at(axis) * loc.at(axis))) +
wl_coeff.at(axis) * pd.min_exp.at(axis) * x_min_sum) /
(min_sum * min_sum);
NPNR_ASSERT(std::isfinite(d_min));
}
if (pd.has_max_exp(axis)) {
double max_sum = nd.max_exp.at(axis), x_max_sum = nd.x_max_exp.at(axis);
d_max = (max_sum * (pd.max_exp.at(axis) * (1.0f + wl_coeff.at(axis) * loc.at(axis))) -
wl_coeff.at(axis) * pd.max_exp.at(axis) * x_max_sum) /
(max_sum * max_sum);
NPNR_ASSERT(std::isfinite(d_max));
}
float crit = 0.0;
if (cfg.timing_driven) {
@ -853,6 +856,7 @@ class StaticPlacer
gradient += weight * (d_min - d_max);
}
NPNR_ASSERT(std::isfinite(gradient));
return gradient;
}
@ -917,6 +921,7 @@ class StaticPlacer
}
const float eta = 1e-1;
float init_dens_penalty = eta * (wirelen_sum / force_sum);
NPNR_ASSERT(std::isfinite(init_dens_penalty));
log_info("initial density penalty: %f\n", init_dens_penalty);
dens_penalty.resize(groups.size(), init_dens_penalty);
update_potentials(true); // set initial potential

7
common/place/placer_static.h
View File

@ -56,6 +56,8 @@ struct PlacerStaticCfg
// These cell types will be randomly locked to prevent singular matrices
pool<IdString> ioBufTypes;
// Nets driven by these cell types will be ignored
pool<IdString> glbBufTypes;
int hpwl_scale_x = 1;
int hpwl_scale_y = 1;
bool timing_driven = false;
@ -68,9 +70,8 @@ struct PlacerStaticCfg
int logic_groups = 2;
// this is an optional callback to override the area of a cell e.g. based on configuration
std::function<std::optional<StaticRect>(Context *, const CellInfo *)> get_cell_area_override = [](Context *, const CellInfo *) {
return std::optional<StaticRect>{};
};
std::function<std::optional<StaticRect>(Context *, const CellInfo *)> get_cell_area_override =
[](Context *, const CellInfo *) { return std::optional<StaticRect>{}; };
};
extern bool placer_static(Context *ctx, PlacerStaticCfg cfg);

5
himbaechel/uarch/xilinx/xilinx.cc
View File

@ -302,6 +302,11 @@ void XilinxImpl::configurePlacerStatic(PlacerStaticCfg &cfg)
cfg.hpwl_scale_x = 2;
cfg.hpwl_scale_y = 1;
cfg.glbBufTypes.insert(id_PSEUDO_GND);
cfg.glbBufTypes.insert(id_PSEUDO_VCC);
cfg.glbBufTypes.insert(id_BUFGCTRL);
cfg.glbBufTypes.insert(id_BUFG_BUFG);
{
cfg.cell_groups.emplace_back();
auto &comb = cfg.cell_groups.back();