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WIP: static: improve region constraint handling 

Signed-off-by: gatecat <gatecat@ds0.me>
This commit is contained in:
gatecat 2026-06-21 09:53:14 +02:00
parent 47d88a6aa7
commit 7086ca791e
1 changed files with 39 additions and 12 deletions
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51
common/place/placer_static.cc
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@ -505,13 +505,33 @@ class StaticPlacer
}
}
RealPair limit_to_reg(Region *reg, RealPair val)
RealPair get_region_gradient(Region *reg, RealPair pos)
{
RealPair val(0, 0);
if (reg == nullptr)
return val;
const auto &b = constraint_region_bounds_place[reg->name];
return RealPair(std::max<float>(std::min<float>(val.x, b.x1), b.x0),
std::max<float>(std::min<float>(val.y, b.y1), b.y0));
float cx = (b.x0 + b.x1) / 2.f, w = (b.x1 - b.x0);
float cy = (b.y0 + b.y1) / 2.f, h = (b.y1 - b.y0);
const float thresh = 0.9f / 2.f;
if (pos.x < (cx - w * thresh)) {
val.x = ((cx - w * thresh) - pos.x);
} else if (pos.x > (cx + w * thresh)) {
val.x = ((cx + w * thresh) - pos.x);
}
if (pos.y < (cy - h * thresh)) {
val.y = ((cy - h * thresh) - pos.y);
} else if (pos.y > (cy + h * thresh)) {
val.y = ((cy + h * thresh) - pos.y);
}
// if ((iter % 20) == 0 && !b.contains(int(pos.x + 0.5f), int(pos.y + 0.5f))) {
// log(" %s (%.1f, %.1f) (%d, %d, %d, %d) gx=%.2f gy=%.2f %s\n",
// ctx->nameOf(reg), pos.x, pos.y, b.x0, b.y0, b.x1, b.y1,
// val.x, val.y, b.contains(int(pos.x + 0.5f), int(pos.y + 0.5f)) ? "" : "***");
// }
return val;
}
void init_cells()
@ -1045,7 +1065,7 @@ class StaticPlacer
}
// Third loop: compute total gradient, and precondition
// TODO: ALM as well as simple penalty
for (auto &cell : mcells) {
for (int idx = 0; idx < int(mcells.size()); idx++) {
#if 0
if (!cell.is_spacer) {
printf("%d (%f, %f) wirelen_grad: (%f,%f) density_grad: (%f,%f)\n", iter, cell.ref_pos.x,
@ -1054,13 +1074,24 @@ class StaticPlacer
}
#endif
// Preconditioner from replace for now
auto &cell = mcells.at(idx);
float precond = std::max(1.0f, float(cell.pin_count) + dens_penalty[cell.group] * cell.rect.area());
// Extra gradient to pull cells towards their region constraint bounds
RealPair region_constr_grad(0.f, 0.f);
if (idx < int(ccells.size()) && ccells.at(idx).base_cell->region != nullptr) {
region_constr_grad =
get_region_gradient(ccells.at(idx).base_cell->region, ref ? cell.ref_pos : cell.pos);
}
if (ref) {
cell.ref_total_grad =
((cell.ref_wl_grad * -1) - cell.ref_dens_grad * dens_penalty[cell.group]) / precond;
cell.ref_total_grad = ((cell.ref_wl_grad * -1) -
cell.ref_dens_grad * dens_penalty[cell.group] - region_constr_grad) /
precond;
} else {
cell.total_grad = ((cell.wl_grad * -1) - cell.dens_grad * dens_penalty[cell.group]) / precond;
cell.total_grad =
((cell.wl_grad * -1) - cell.dens_grad * dens_penalty[cell.group] - region_constr_grad) /
precond;
}
}
}
@ -1262,10 +1293,6 @@ class StaticPlacer
cell.pos = clamp_loc(cell.ref_pos - cell.ref_total_grad * steplen);
// compute reference position
cell.ref_pos = clamp_loc(cell.pos + (cell.pos - cell.last_pos) * ((nesterov_a - 1) / a_next));
if (idx < int(ccells.size()) && ccells.at(idx).base_cell->region != nullptr) {
cell.pos = limit_to_reg(ccells.at(idx).base_cell->region, cell.pos);
cell.ref_pos = limit_to_reg(ccells.at(idx).base_cell->region, cell.ref_pos);
}
}
nesterov_a = a_next;
update_chains();