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[vpr][place] refactoring variables in net_cost_handler #2644

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[vpr][place] refactoring variables in net_cost_handler #2644

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5102cc8
[vpr][place] refactoring variables in net_cost_handler
Jul 13, 2024
4e44de6
[vpr][place] fixing comments and better variable names
Jul 13, 2024
38c6a85
[vpr][placer] fixed comment's grammar
Jul 14, 2024
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115 changes: 58 additions & 57 deletions vpr/src/place/net_cost_handler.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -55,14 +55,10 @@ static vtr::NdMatrix<float, 2> chanx_place_cost_fac({0, 0}); // [0...device_ctx.
static vtr::NdMatrix<float, 2> chany_place_cost_fac({0, 0}); // [0...device_ctx.grid.height()-2]

/**
* @brief Cost of a net, and a temporary cost of a net used during move assessment.
* @brief For the first two element in the struct: Cost of a net, and a temporary cost of a net used during move assessment.
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You should use the member names (net_cost etc.) instead of the order in the struct, in case a member is added or deleted or reordered in the future. It also makes the comment more self-contained.

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Also comment that there is one entry per cluster level net [0...cluster_ctx.clb_nlist.nets().size()-1] for each of these vectors. (Mention this early in the comment).

* We also use negative cost values in proposed_net_cost as a flag to indicate that
* the cost of a net has not yet been updated.
*/
static vtr::vector<ClusterNetId, double> net_cost, proposed_net_cost;

/** *
* @brief Flag array to indicate whether the specific bounding box has been updated
* For the last one element in the struct: Flag array to indicate whether the specific bounding box has been updated
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Change to "bb_update_status: flag array ..."

* in this particular swap or not. If it has been updated before, the code
* must use the updated data, instead of the out-of-date data passed into the
* subroutine, particularly used in try_swap(). The value NOT_UPDATED_YET
Expand All @@ -74,7 +70,12 @@ static vtr::vector<ClusterNetId, double> net_cost, proposed_net_cost;
* bounding box is got from scratch, so the bounding box would definitely be
* right, DO NOT update again.
*/
static vtr::vector<ClusterNetId, NetUpdateState> bb_updated_before; // [0...cluster_ctx.clb_nlist.nets().size()-1]
struct NetInfo {
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I suggest a somewhat more descriptive name, e.g. PLNetCost.

vtr::vector<ClusterNetId, double> net_cost;
vtr::vector<ClusterNetId, double> proposed_net_cost;
vtr::vector<ClusterNetId, NetUpdateState> bb_update_status; // [0...cluster_ctx.clb_nlist.nets().size()-1]
} NetInfo;
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Isn't this making a variable NetInfo as well as a struct called NetInfo?

static struct NetInfo net_info;
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Can just write
static NetInfo net_info;
(or better yet, a renamed
static PLNetCost pl_net_cost;
)


/* The following arrays are used by the try_swap function for speed. */

Expand Down Expand Up @@ -477,7 +478,7 @@ static void update_net_bb(const ClusterNetId& net,
if (cluster_ctx.clb_nlist.net_sinks(net).size() < SMALL_NET) {
//For small nets brute-force bounding box update is faster

if (bb_updated_before[net] == NetUpdateState::NOT_UPDATED_YET) { //Only once per-net
if (net_info.bb_update_status[net] == NetUpdateState::NOT_UPDATED_YET) { //Only once per-net
get_non_updatable_bb(net,
ts_bb_coord_new[net],
ts_layer_sink_pin_count[size_t(net)]);
Expand Down Expand Up @@ -515,7 +516,7 @@ static void update_net_layer_bb(const ClusterNetId& net,
if (cluster_ctx.clb_nlist.net_sinks(net).size() < SMALL_NET) {
//For small nets brute-force bounding box update is faster

if (bb_updated_before[net] == NetUpdateState::NOT_UPDATED_YET) { //Only once per-net
if (net_info.bb_update_status[net] == NetUpdateState::NOT_UPDATED_YET) { //Only once per-net
get_non_updatable_layer_bb(net,
layer_ts_bb_coord_new[net],
ts_layer_sink_pin_count[size_t(net)]);
Expand Down Expand Up @@ -651,13 +652,13 @@ static void update_td_delta_costs(const PlaceDelayModel* delay_model,
static void record_affected_net(const ClusterNetId net,
int& num_affected_nets) {
/* Record effected nets. */
if (proposed_net_cost[net] < 0.) {
if (net_info.proposed_net_cost[net] < 0.) {
/* Net not marked yet. */
ts_nets_to_update[num_affected_nets] = net;
num_affected_nets++;

/* Flag to say we've marked this net. */
proposed_net_cost[net] = 1.;
net_info.proposed_net_cost[net] = 1.;
}
}

Expand Down Expand Up @@ -875,18 +876,18 @@ static void update_bb(ClusterNetId net_id,
pin_old_loc.layer_num = max(min<int>(pin_old_loc.layer_num, device_ctx.grid.get_num_layers() - 1), 0);

/* Check if the net had been updated before. */
if (bb_updated_before[net_id] == NetUpdateState::GOT_FROM_SCRATCH) {
if (net_info.bb_update_status[net_id] == NetUpdateState::GOT_FROM_SCRATCH) {
/* The net had been updated from scratch, DO NOT update again! */
return;
}

vtr::NdMatrixProxy<int, 1> curr_num_sink_pin_layer = (bb_updated_before[net_id] == NetUpdateState::NOT_UPDATED_YET) ? place_move_ctx.num_sink_pin_layer[size_t(net_id)] : num_sink_pin_layer_new;
vtr::NdMatrixProxy<int, 1> curr_num_sink_pin_layer = (net_info.bb_update_status[net_id] == NetUpdateState::NOT_UPDATED_YET) ? place_move_ctx.num_sink_pin_layer[size_t(net_id)] : num_sink_pin_layer_new;

if (bb_updated_before[net_id] == NetUpdateState::NOT_UPDATED_YET) {
if (net_info.bb_update_status[net_id] == NetUpdateState::NOT_UPDATED_YET) {
/* The net had NOT been updated before, could use the old values */
curr_bb_edge = &place_move_ctx.bb_num_on_edges[net_id];
curr_bb_coord = &place_move_ctx.bb_coords[net_id];
bb_updated_before[net_id] = NetUpdateState::UPDATED_ONCE;
net_info.bb_update_status[net_id] = NetUpdateState::UPDATED_ONCE;
} else {
/* The net had been updated before, must use the new values */
curr_bb_coord = &bb_coord_new;
Expand All @@ -902,7 +903,7 @@ static void update_bb(ClusterNetId net_id,
if (pin_old_loc.x == curr_bb_coord->xmax) { /* Old position at xmax. */
if (curr_bb_edge->xmax == 1) {
get_bb_from_scratch(net_id, bb_coord_new, bb_edge_new, num_sink_pin_layer_new);
bb_updated_before[net_id] = NetUpdateState::GOT_FROM_SCRATCH;
net_info.bb_update_status[net_id] = NetUpdateState::GOT_FROM_SCRATCH;
return;
} else {
bb_edge_new.xmax = curr_bb_edge->xmax - 1;
Expand Down Expand Up @@ -934,7 +935,7 @@ static void update_bb(ClusterNetId net_id,
if (pin_old_loc.x == curr_bb_coord->xmin) { /* Old position at xmin. */
if (curr_bb_edge->xmin == 1) {
get_bb_from_scratch(net_id, bb_coord_new, bb_edge_new, num_sink_pin_layer_new);
bb_updated_before[net_id] = NetUpdateState::GOT_FROM_SCRATCH;
net_info.bb_update_status[net_id] = NetUpdateState::GOT_FROM_SCRATCH;
return;
} else {
bb_edge_new.xmin = curr_bb_edge->xmin - 1;
Expand Down Expand Up @@ -975,7 +976,7 @@ static void update_bb(ClusterNetId net_id,
if (pin_old_loc.y == curr_bb_coord->ymax) { /* Old position at ymax. */
if (curr_bb_edge->ymax == 1) {
get_bb_from_scratch(net_id, bb_coord_new, bb_edge_new, num_sink_pin_layer_new);
bb_updated_before[net_id] = NetUpdateState::GOT_FROM_SCRATCH;
net_info.bb_update_status[net_id] = NetUpdateState::GOT_FROM_SCRATCH;
return;
} else {
bb_edge_new.ymax = curr_bb_edge->ymax - 1;
Expand Down Expand Up @@ -1007,7 +1008,7 @@ static void update_bb(ClusterNetId net_id,
if (pin_old_loc.y == curr_bb_coord->ymin) { /* Old position at ymin. */
if (curr_bb_edge->ymin == 1) {
get_bb_from_scratch(net_id, bb_coord_new, bb_edge_new, num_sink_pin_layer_new);
bb_updated_before[net_id] = NetUpdateState::GOT_FROM_SCRATCH;
net_info.bb_update_status[net_id] = NetUpdateState::GOT_FROM_SCRATCH;
return;
} else {
bb_edge_new.ymin = curr_bb_edge->ymin - 1;
Expand Down Expand Up @@ -1057,7 +1058,7 @@ static void update_bb(ClusterNetId net_id,
if (pin_old_loc.layer_num == curr_bb_coord->layer_max) {
if (curr_bb_edge->layer_max == 1) {
get_bb_from_scratch(net_id, bb_coord_new, bb_edge_new, num_sink_pin_layer_new);
bb_updated_before[net_id] = NetUpdateState::GOT_FROM_SCRATCH;
net_info.bb_update_status[net_id] = NetUpdateState::GOT_FROM_SCRATCH;
return;
} else {
bb_edge_new.layer_max = curr_bb_edge->layer_max - 1;
Expand Down Expand Up @@ -1086,7 +1087,7 @@ static void update_bb(ClusterNetId net_id,
if (pin_old_loc.layer_num == curr_bb_coord->layer_min) {
if (curr_bb_edge->layer_min == 1) {
get_bb_from_scratch(net_id, bb_coord_new, bb_edge_new, num_sink_pin_layer_new);
bb_updated_before[net_id] = NetUpdateState::GOT_FROM_SCRATCH;
net_info.bb_update_status[net_id] = NetUpdateState::GOT_FROM_SCRATCH;
return;
} else {
bb_edge_new.layer_min = curr_bb_edge->layer_min - 1;
Expand Down Expand Up @@ -1123,8 +1124,8 @@ static void update_bb(ClusterNetId net_id,
bb_edge_new.layer_max = curr_bb_edge->layer_max;
}

if (bb_updated_before[net_id] == NetUpdateState::NOT_UPDATED_YET) {
bb_updated_before[net_id] = NetUpdateState::UPDATED_ONCE;
if (net_info.bb_update_status[net_id] == NetUpdateState::NOT_UPDATED_YET) {
net_info.bb_update_status[net_id] = NetUpdateState::UPDATED_ONCE;
}
}

Expand All @@ -1145,19 +1146,19 @@ static void update_layer_bb(ClusterNetId net_id,
pin_old_loc.y = max(min<int>(pin_old_loc.y, device_ctx.grid.height() - 2), 1); //-2 for no perim channels

/* Check if the net had been updated before. */
if (bb_updated_before[net_id] == NetUpdateState::GOT_FROM_SCRATCH) {
if (net_info.bb_update_status[net_id] == NetUpdateState::GOT_FROM_SCRATCH) {
/* The net had been updated from scratch, DO NOT update again! */
return;
}

const vtr::NdMatrixProxy<int, 1> curr_layer_pin_sink_count = (bb_updated_before[net_id] == NetUpdateState::NOT_UPDATED_YET) ? place_move_ctx.num_sink_pin_layer[size_t(net_id)] : bb_pin_sink_count_new;
const vtr::NdMatrixProxy<int, 1> curr_layer_pin_sink_count = (net_info.bb_update_status[net_id] == NetUpdateState::NOT_UPDATED_YET) ? place_move_ctx.num_sink_pin_layer[size_t(net_id)] : bb_pin_sink_count_new;

const std::vector<t_2D_bb>*curr_bb_edge, *curr_bb_coord;
if (bb_updated_before[net_id] == NetUpdateState::NOT_UPDATED_YET) {
if (net_info.bb_update_status[net_id] == NetUpdateState::NOT_UPDATED_YET) {
/* The net had NOT been updated before, could use the old values */
curr_bb_edge = &place_move_ctx.layer_bb_num_on_edges[net_id];
curr_bb_coord = &place_move_ctx.layer_bb_coords[net_id];
bb_updated_before[net_id] = NetUpdateState::UPDATED_ONCE;
net_info.bb_update_status[net_id] = NetUpdateState::UPDATED_ONCE;
} else {
/* The net had been updated before, must use the new values */
curr_bb_edge = &bb_edge_new;
Expand Down Expand Up @@ -1199,8 +1200,8 @@ static void update_layer_bb(ClusterNetId net_id,
bb_coord_new);
}

if (bb_updated_before[net_id] == NetUpdateState::NOT_UPDATED_YET) {
bb_updated_before[net_id] = NetUpdateState::UPDATED_ONCE;
if (net_info.bb_update_status[net_id] == NetUpdateState::NOT_UPDATED_YET) {
net_info.bb_update_status[net_id] = NetUpdateState::UPDATED_ONCE;
}
}

Expand Down Expand Up @@ -1231,7 +1232,7 @@ static inline void update_bb_same_layer(ClusterNetId net_id,
curr_bb_coord[layer_num].xmax,
bb_edge_new[layer_num].xmax,
bb_coord_new[layer_num].xmax);
if (bb_updated_before[net_id] == NetUpdateState::GOT_FROM_SCRATCH) {
if (net_info.bb_update_status[net_id] == NetUpdateState::GOT_FROM_SCRATCH) {
return;
}
}
Expand All @@ -1254,7 +1255,7 @@ static inline void update_bb_same_layer(ClusterNetId net_id,
curr_bb_coord[layer_num].xmin,
bb_edge_new[layer_num].xmin,
bb_coord_new[layer_num].xmin);
if (bb_updated_before[net_id] == NetUpdateState::GOT_FROM_SCRATCH) {
if (net_info.bb_update_status[net_id] == NetUpdateState::GOT_FROM_SCRATCH) {
return;
}
}
Expand All @@ -1278,7 +1279,7 @@ static inline void update_bb_same_layer(ClusterNetId net_id,
curr_bb_coord[layer_num].ymax,
bb_edge_new[layer_num].ymax,
bb_coord_new[layer_num].ymax);
if (bb_updated_before[net_id] == NetUpdateState::GOT_FROM_SCRATCH) {
if (net_info.bb_update_status[net_id] == NetUpdateState::GOT_FROM_SCRATCH) {
return;
}
}
Expand All @@ -1301,7 +1302,7 @@ static inline void update_bb_same_layer(ClusterNetId net_id,
curr_bb_coord[layer_num].ymin,
bb_edge_new[layer_num].ymin,
bb_coord_new[layer_num].ymin);
if (bb_updated_before[net_id] == NetUpdateState::GOT_FROM_SCRATCH) {
if (net_info.bb_update_status[net_id] == NetUpdateState::GOT_FROM_SCRATCH) {
return;
}
}
Expand Down Expand Up @@ -1346,7 +1347,7 @@ static inline void update_bb_layer_changed(ClusterNetId net_id,
curr_bb_coord[old_layer_num].xmax,
bb_edge_new[old_layer_num].xmax,
bb_coord_new[old_layer_num].xmax);
if (bb_updated_before[net_id] == NetUpdateState::GOT_FROM_SCRATCH) {
if (net_info.bb_update_status[net_id] == NetUpdateState::GOT_FROM_SCRATCH) {
return;
}
} else if (x_old == curr_bb_coord[old_layer_num].xmin) {
Expand All @@ -1358,7 +1359,7 @@ static inline void update_bb_layer_changed(ClusterNetId net_id,
curr_bb_coord[old_layer_num].xmin,
bb_edge_new[old_layer_num].xmin,
bb_coord_new[old_layer_num].xmin);
if (bb_updated_before[net_id] == NetUpdateState::GOT_FROM_SCRATCH) {
if (net_info.bb_update_status[net_id] == NetUpdateState::GOT_FROM_SCRATCH) {
return;
}
}
Expand All @@ -1372,7 +1373,7 @@ static inline void update_bb_layer_changed(ClusterNetId net_id,
curr_bb_coord[old_layer_num].ymax,
bb_edge_new[old_layer_num].ymax,
bb_coord_new[old_layer_num].ymax);
if (bb_updated_before[net_id] == NetUpdateState::GOT_FROM_SCRATCH) {
if (net_info.bb_update_status[net_id] == NetUpdateState::GOT_FROM_SCRATCH) {
return;
}
} else if (y_old == curr_bb_coord[old_layer_num].ymin) {
Expand All @@ -1384,7 +1385,7 @@ static inline void update_bb_layer_changed(ClusterNetId net_id,
curr_bb_coord[old_layer_num].ymin,
bb_edge_new[old_layer_num].ymin,
bb_coord_new[old_layer_num].ymin);
if (bb_updated_before[net_id] == NetUpdateState::GOT_FROM_SCRATCH) {
if (net_info.bb_update_status[net_id] == NetUpdateState::GOT_FROM_SCRATCH) {
return;
}
}
Expand Down Expand Up @@ -1424,7 +1425,7 @@ static inline void update_bb_edge(ClusterNetId net_id,
bb_edge_new,
bb_coord_new,
bb_layer_pin_sink_count);
bb_updated_before[net_id] = NetUpdateState::GOT_FROM_SCRATCH;
net_info.bb_update_status[net_id] = NetUpdateState::GOT_FROM_SCRATCH;
return;
} else {
new_num_block_on_edge = old_num_block_on_edge - 1;
Expand Down Expand Up @@ -1838,7 +1839,7 @@ static double recompute_bb_cost() {
for (auto net_id : cluster_ctx.clb_nlist.nets()) { /* for each net ... */
if (!cluster_ctx.clb_nlist.net_is_ignored(net_id)) { /* Do only if not ignored. */
/* Bounding boxes don't have to be recomputed; they're correct. */
cost += net_cost[net_id];
cost += net_info.net_cost[net_id];
}
}

Expand All @@ -1863,15 +1864,15 @@ static void set_bb_delta_cost(const int num_affected_nets, double& bb_delta_c) {
const auto& cube_bb = g_vpr_ctx.placement().cube_bb;

if (cube_bb) {
proposed_net_cost[net_id] = get_net_cost(net_id,
net_info.proposed_net_cost[net_id] = get_net_cost(net_id,
ts_bb_coord_new[net_id]);
} else {
proposed_net_cost[net_id] = get_net_layer_bb_wire_cost(net_id,
net_info.proposed_net_cost[net_id] = get_net_layer_bb_wire_cost(net_id,
layer_ts_bb_coord_new[net_id],
ts_layer_sink_pin_count[size_t(net_id)]);
}

bb_delta_c += proposed_net_cost[net_id] - net_cost[net_id];
bb_delta_c += net_info.proposed_net_cost[net_id] - net_info.net_cost[net_id];
}
}

Expand Down Expand Up @@ -1945,8 +1946,8 @@ double comp_bb_cost(e_cost_methods method) {
place_move_ctx.num_sink_pin_layer[size_t(net_id)]);
}

net_cost[net_id] = get_net_cost(net_id, place_move_ctx.bb_coords[net_id]);
cost += net_cost[net_id];
net_info.net_cost[net_id] = get_net_cost(net_id, place_move_ctx.bb_coords[net_id]);
cost += net_info.net_cost[net_id];
if (method == CHECK)
expected_wirelength += get_net_wirelength_estimate(net_id, place_move_ctx.bb_coords[net_id]);
}
Expand Down Expand Up @@ -1982,10 +1983,10 @@ double comp_layer_bb_cost(e_cost_methods method) {
place_move_ctx.num_sink_pin_layer[size_t(net_id)]);
}

net_cost[net_id] = get_net_layer_bb_wire_cost(net_id,
net_info.net_cost[net_id] = get_net_layer_bb_wire_cost(net_id,
place_move_ctx.layer_bb_coords[net_id],
place_move_ctx.num_sink_pin_layer[size_t(net_id)]);
cost += net_cost[net_id];
cost += net_info.net_cost[net_id];
if (method == CHECK)
expected_wirelength += get_net_wirelength_from_layer_bb(net_id,
place_move_ctx.layer_bb_coords[net_id],
Expand Down Expand Up @@ -2029,11 +2030,11 @@ void update_move_nets(int num_nets_affected,
}
}

net_cost[net_id] = proposed_net_cost[net_id];
net_info.net_cost[net_id] = net_info.proposed_net_cost[net_id];

/* negative proposed_net_cost value is acting as a flag to mean not computed yet. */
proposed_net_cost[net_id] = -1;
bb_updated_before[net_id] = NetUpdateState::NOT_UPDATED_YET;
net_info.proposed_net_cost[net_id] = -1;
net_info.bb_update_status[net_id] = NetUpdateState::NOT_UPDATED_YET;
}
}

Expand All @@ -2042,8 +2043,8 @@ void reset_move_nets(int num_nets_affected) {
for (int inet_affected = 0; inet_affected < num_nets_affected;
inet_affected++) {
ClusterNetId net_id = ts_nets_to_update[inet_affected];
proposed_net_cost[net_id] = -1;
bb_updated_before[net_id] = NetUpdateState::NOT_UPDATED_YET;
net_info.proposed_net_cost[net_id] = -1;
net_info.bb_update_status[net_id] = NetUpdateState::NOT_UPDATED_YET;
}
}

Expand Down Expand Up @@ -2217,18 +2218,18 @@ void free_chan_w_factors_for_place_cost () {
}

void init_place_move_structs(size_t num_nets) {
net_cost.resize(num_nets, -1.);
proposed_net_cost.resize(num_nets, -1.);
net_info.net_cost.resize(num_nets, -1.);
net_info.proposed_net_cost.resize(num_nets, -1.);
/* Used to store costs for moves not yet made and to indicate when a net's *
* cost has been recomputed. proposed_net_cost[inet] < 0 means net's cost hasn't *
* been recomputed. */
bb_updated_before.resize(num_nets, NetUpdateState::NOT_UPDATED_YET);
net_info.bb_update_status.resize(num_nets, NetUpdateState::NOT_UPDATED_YET);
}

void free_place_move_structs() {
vtr::release_memory(net_cost);
vtr::release_memory(proposed_net_cost);
vtr::release_memory(bb_updated_before);
vtr::release_memory(net_info.net_cost);
vtr::release_memory(net_info.proposed_net_cost);
vtr::release_memory(net_info.bb_update_status);
}

void init_try_swap_net_cost_structs(size_t num_nets, bool cube_bb) {
Expand Down