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timing_opt: Neigbour bel validity checking

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Signed-off-by: David Shah <dave@ds0.me>
This commit is contained in:
David Shah 2018-12-01 14:06:51 +00:00
parent 2de506c071
commit cd9a65a84c
1 changed files with 48 additions and 5 deletions
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51
common/timing_opt.cc
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@ -106,7 +106,10 @@ class TimingOptimiser
goto unbind;
}
if (!check_cell_delay_limits(cell) || (other_cell != nullptr && !check_cell_delay_limits(other_cell))) {
result = false;
goto unbind;
}
unbind:
ctx->unbindBel(newBel);
@ -120,9 +123,10 @@ unbind:
return result;
}
void find_neighbours(CellInfo *cell, int d) {
int find_neighbours(CellInfo *cell, IdString prev_cell, int d, bool allow_swap) {
BelId curr = cell->bel;
Loc curr_loc = ctx->getBelLocation(curr);
int found_count = 0;
for (int dy = -d; dy <= d; dy++) {
for (int dx = -d; dx <= d; dx++) {
if (dx == 0 && dy == 0)
@ -143,14 +147,53 @@ unbind:
bound_bels_at_loc.push_back(bel);
}
}
bool found = false;
BelId candidate;
if (found)
while (!free_bels_at_loc.empty() && !bound_bels_at_loc.empty()) {
BelId try_bel;
if (!free_bels_at_loc.empty()) {
int try_idx = ctx->rng(int(free_bels_at_loc.size()));
try_bel = free_bels_at_loc.at(try_idx);
free_bels_at_loc.erase(free_bels_at_loc.begin() + try_idx);
} else {
int try_idx = ctx->rng(int(bound_bels_at_loc.size()));
try_bel = bound_bels_at_loc.at(try_idx);
bound_bels_at_loc.erase(bound_bels_at_loc.begin() + try_idx);
}
if (bel_candidate_cells.count(try_bel) && !allow_swap) {
// Overlap is only allowed if it is with the previous cell (this is handled by removing those
// edges in the graph), or if allow_swap is true to deal with cases where overlap means few neighbours
// are identified
if (bel_candidate_cells.at(try_bel).size() > 1 || (bel_candidate_cells.at(try_bel).size() == 0 ||
*(bel_candidate_cells.at(try_bel).begin()) != prev_cell))
continue;
}
if (acceptable_bel_candidate(cell, try_bel)) {
candidate = try_bel;
break;
}
}
if (candidate != BelId()) {
cell_neighbour_bels[cell->name].insert(candidate);
bel_candidate_cells[candidate].insert(cell->name);
// Work out if we need to delete any overlap
std::vector<IdString> overlap;
for (auto other : bel_candidate_cells[candidate])
if (other != cell->name && other != prev_cell)
overlap.push_back(other);
if (overlap.size() > 0)
NPNR_ASSERT(allow_swap);
for (auto ov : overlap) {
bel_candidate_cells[candidate].erase(ov);
cell_neighbour_bels[ov].erase(candidate);
}
}
}
}
return found_count;
}
// Current candidate Bels for cells (linked in both direction>
std::vector<IdString> path_cells;
std::unordered_map<IdString, std::unordered_set<BelId>> cell_neighbour_bels;