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placer1: Allow swapping chains with other chains

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Signed-off-by: gatecat <gatecat@ds0.me>
This commit is contained in:
gatecat 2021-09-17 21:34:08 +01:00
parent 7c82a04df5
commit f119f56e63
1 changed files with 105 additions and 47 deletions
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142
common/placer1.cc
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@ -119,6 +119,12 @@ class SAPlacer
region_bounds[r->name] = bb; region_bounds[r->name] = bb;
} }
build_port_index(); build_port_index();
for (auto &cell : ctx->cells) {
CellInfo *ci = cell.second.get();
if (ci->cluster == ClusterId())
continue;
cluster2cell[ci->cluster].push_back(ci);
}
} }
~SAPlacer() ~SAPlacer()
@ -616,56 +622,99 @@ class SAPlacer
bool try_swap_chain(CellInfo *cell, BelId newBase) bool try_swap_chain(CellInfo *cell, BelId newBase)
{ {
std::vector<std::pair<CellInfo *, Loc>> cell_rel; std::vector<std::pair<CellInfo *, Loc>> cell_rel;
pool<IdString> cells; dict<IdString, BelId> moved_cells;
std::vector<std::pair<CellInfo *, BelId>> moves_made;
std::vector<std::pair<CellInfo *, BelId>> dest_bels; std::vector<std::pair<CellInfo *, BelId>> dest_bels;
double delta = 0; double delta = 0;
int orig_share_cost = total_net_share; int orig_share_cost = total_net_share;
moveChange.reset(this); moveChange.reset(this);
#if 0 #if CHAIN_DEBUG
if (ctx->debug)
log_info("finding cells for chain swap %s\n", cell->name.c_str(ctx)); log_info("finding cells for chain swap %s\n", cell->name.c_str(ctx));
#endif #endif
if (!ctx->getClusterPlacement(cell->cluster, newBase, dest_bels)) std::queue<std::pair<ClusterId, BelId>> displaced_clusters;
return false; displaced_clusters.emplace(cell->cluster, newBase);
while (!displaced_clusters.empty()) {
for (const auto &db : dest_bels) auto cursor = displaced_clusters.front();
cells.insert(db.first->name); displaced_clusters.pop();
if (!ctx->getClusterPlacement(cursor.first, cursor.second, dest_bels))
goto swap_fail;
for (const auto &db : dest_bels) {
// Ensure the cluster is ripped up
if (db.first->bel != BelId()) {
moved_cells[db.first->name] = db.first->bel;
#if CHAIN_DEBUG
log_info("%d unbind %s\n", __LINE__, ctx->nameOfBel(db.first->bel));
#endif
ctx->unbindBel(db.first->bel);
}
}
for (const auto &db : dest_bels) { for (const auto &db : dest_bels) {
CellInfo *bound = ctx->getBoundBelCell(db.second); CellInfo *bound = ctx->getBoundBelCell(db.second);
// We don't consider swapping chains with other chains, at least for the time being - unless it is BelId old_bel = moved_cells.at(db.first->name);
// part of this chain if (!ctx->checkBelAvail(old_bel) && bound != nullptr) {
if (bound != nullptr && !cells.count(bound->name) && // Simple swap no longer possible
(bound->belStrength >= STRENGTH_STRONG || bound->cluster != ClusterId())) goto swap_fail;
return false;
if (bound != nullptr)
if (!ctx->isValidBelForCellType(bound->type, db.first->bel))
return false;
} }
#if 0 if (bound != nullptr) {
if (ctx->debug) if (moved_cells.count(bound->name)) {
log_info("trying chain swap %s\n", cell->name.c_str(ctx)); // Don't move a cell multiple times in the same go
goto swap_fail;
} else if (bound->belStrength > STRENGTH_STRONG) {
goto swap_fail;
} else if (bound->cluster != ClusterId()) {
// Displace the entire cluster
Loc old_loc = ctx->getBelLocation(old_bel);
Loc bound_loc = ctx->getBelLocation(bound->bel);
Loc root_loc = ctx->getBelLocation(ctx->getClusterRootCell(bound->cluster)->bel);
BelId new_root = ctx->getBelByLocation(Loc(old_loc.x + (root_loc.x - bound_loc.x),
old_loc.y + (root_loc.y - bound_loc.y),
old_loc.z + (root_loc.z - bound_loc.z)));
if (new_root == BelId())
goto swap_fail;
for (auto cluster_cell : cluster2cell.at(bound->cluster)) {
moved_cells[cluster_cell->name] = cluster_cell->bel;
#if CHAIN_DEBUG
log_info("%d unbind %s\n", __LINE__, ctx->nameOfBel(cluster_cell->bel));
#endif #endif
// <cell, oldBel> ctx->unbindBel(cluster_cell->bel);
for (const auto &db : dest_bels) {
BelId oldBel = swap_cell_bels(db.first, db.second);
moves_made.emplace_back(std::make_pair(db.first, oldBel));
CellInfo *bound = ctx->getBoundBelCell(oldBel);
add_move_cell(moveChange, db.first, oldBel);
if (bound != nullptr)
add_move_cell(moveChange, bound, db.second);
} }
for (const auto &mm : moves_made) { displaced_clusters.emplace(bound->cluster, new_root);
if (!ctx->isBelLocationValid(mm.first->bel) || !mm.first->testRegion(mm.first->bel)) } else {
goto swap_fail; // Just a single cell to move
if (!ctx->isBelLocationValid(mm.second)) moved_cells[bound->name] = bound->bel;
goto swap_fail; #if CHAIN_DEBUG
CellInfo *bound = ctx->getBoundBelCell(mm.second); log_info("%d unbind %s\n", __LINE__, ctx->nameOfBel(bound->bel));
if (bound && !bound->testRegion(bound->bel)) log_info("%d bind %s %s\n", __LINE__, ctx->nameOfBel(old_bel), ctx->nameOf(bound));
#endif
ctx->unbindBel(bound->bel);
ctx->bindBel(old_bel, bound, STRENGTH_WEAK);
add_move_cell(moveChange, bound, moved_cells.at(bound->name));
if (cfg.netShareWeight > 0)
update_nets_by_tile(bound, ctx->getBelLocation(moved_cells.at(bound->name)),
ctx->getBelLocation(old_bel));
}
} else if (!ctx->checkBelAvail(db.second)) {
goto swap_fail; goto swap_fail;
} }
// All those shenanigans should now mean the target bel is free to use
#if CHAIN_DEBUG
log_info("%d bind %s %s\n", __LINE__, ctx->nameOfBel(db.second), ctx->nameOf(db.first));
#endif
ctx->bindBel(db.second, db.first, STRENGTH_WEAK);
add_move_cell(moveChange, db.first, moved_cells.at(db.first->name));
if (cfg.netShareWeight > 0)
update_nets_by_tile(db.first, ctx->getBelLocation(moved_cells.at(db.first->name)),
ctx->getBelLocation(db.second));
}
}
for (const auto &mm : moved_cells) {
CellInfo *cell = ctx->cells.at(mm.first).get();
if (!ctx->isBelLocationValid(cell->bel) || !cell->testRegion(cell->bel))
goto swap_fail;
}
#if CHAIN_DEBUG
log_info("legal chain swap %s\n", cell->name.c_str(ctx));
#endif
compute_cost_changes(moveChange); compute_cost_changes(moveChange);
delta = lambda * (moveChange.timing_delta / last_timing_cost) + delta = lambda * (moveChange.timing_delta / last_timing_cost) +
(1 - lambda) * (double(moveChange.wirelen_delta) / last_wirelen_cost); (1 - lambda) * (double(moveChange.wirelen_delta) / last_wirelen_cost);
@ -675,10 +724,9 @@ class SAPlacer
} }
n_move++; n_move++;
// SA acceptance criteria // SA acceptance criteria
if (delta < 0 || (temp > 1e-9 && (ctx->rng() / float(0x3fffffff)) <= std::exp(-delta / temp))) { if (delta < 0 || (temp > 1e-8 && (ctx->rng() / float(0x3fffffff)) <= std::exp(-delta / temp))) {
n_accept++; n_accept++;
#if 0 #if CHAIN_DEBUG
if (ctx->debug)
log_info("accepted chain swap %s\n", cell->name.c_str(ctx)); log_info("accepted chain swap %s\n", cell->name.c_str(ctx));
#endif #endif
} else { } else {
@ -687,8 +735,15 @@ class SAPlacer
commit_cost_changes(moveChange); commit_cost_changes(moveChange);
return true; return true;
swap_fail: swap_fail:
for (const auto &entry : boost::adaptors::reverse(moves_made)) for (auto cell_pair : moved_cells) {
swap_cell_bels(entry.first, entry.second); CellInfo *cell = ctx->cells.at(cell_pair.first).get();
if (cell->bel != BelId())
ctx->unbindBel(cell->bel);
}
for (auto cell_pair : moved_cells) {
CellInfo *cell = ctx->cells.at(cell_pair.first).get();
ctx->bindBel(cell_pair.second, cell, STRENGTH_WEAK);
}
return false; return false;
} }
@ -1183,6 +1238,9 @@ class SAPlacer
// Fast lookup for cell port to net user index // Fast lookup for cell port to net user index
dict<std::pair<IdString, IdString>, size_t> fast_port_to_user; dict<std::pair<IdString, IdString>, size_t> fast_port_to_user;
// Fast lookup for cell to clusters
dict<ClusterId, std::vector<CellInfo *>> cluster2cell;
// Wirelength and timing cost at last and current iteration // Wirelength and timing cost at last and current iteration
wirelen_t last_wirelen_cost, curr_wirelen_cost; wirelen_t last_wirelen_cost, curr_wirelen_cost;
double last_timing_cost, curr_timing_cost; double last_timing_cost, curr_timing_cost;