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refactor: Remove incorrect uses of the term 'wirelength'

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Signed-off-by: David Shah <davey1576@gmail.com>
This commit is contained in:
David Shah 2018-07-16 17:13:40 +02:00
parent 29df566a60
commit 56fa8cc669
4 changed files with 49 additions and 43 deletions
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18
common/place_common.cc
View File

@ -25,7 +25,7 @@
NEXTPNR_NAMESPACE_BEGIN NEXTPNR_NAMESPACE_BEGIN
// Get the total estimated wirelength for a net // Get the total estimated wirelength for a net
wirelen_t get_net_wirelength(const Context *ctx, const NetInfo *net, float &tns) wirelen_t get_net_metric(const Context *ctx, const NetInfo *net, MetricType type, float &tns)
{ {
wirelen_t wirelength = 0; wirelen_t wirelength = 0;
int driver_x, driver_y; int driver_x, driver_y;
@ -47,7 +47,7 @@ wirelen_t get_net_wirelength(const Context *ctx, const NetInfo *net, float &tns)
CellInfo *load_cell = load.cell; CellInfo *load_cell = load.cell;
if (load_cell->bel == BelId()) if (load_cell->bel == BelId())
continue; continue;
if (ctx->timing_driven) { if (ctx->timing_driven && type == MetricType::COST) {
WireId user_wire = ctx->getWireBelPin(load_cell->bel, ctx->portPinFromId(load.port)); WireId user_wire = ctx->getWireBelPin(load_cell->bel, ctx->portPinFromId(load.port));
delay_t raw_wl = ctx->estimateDelay(drv_wire, user_wire); delay_t raw_wl = ctx->estimateDelay(drv_wire, user_wire);
float slack = ctx->getDelayNS(load.budget) - ctx->getDelayNS(raw_wl); float slack = ctx->getDelayNS(load.budget) - ctx->getDelayNS(raw_wl);
@ -66,7 +66,7 @@ wirelen_t get_net_wirelength(const Context *ctx, const NetInfo *net, float &tns)
xmax = std::max(xmax, load_x); xmax = std::max(xmax, load_x);
ymax = std::max(ymax, load_y); ymax = std::max(ymax, load_y);
} }
if (ctx->timing_driven) { if (ctx->timing_driven && type == MetricType::COST) {
wirelength = wirelen_t((((ymax - ymin) + (xmax - xmin)) * std::min(5.0, (1.0 + std::exp(-worst_slack / 5))))); wirelength = wirelen_t((((ymax - ymin) + (xmax - xmin)) * std::min(5.0, (1.0 + std::exp(-worst_slack / 5)))));
} else { } else {
wirelength = wirelen_t((ymax - ymin) + (xmax - xmin)); wirelength = wirelen_t((ymax - ymin) + (xmax - xmin));
@ -76,7 +76,7 @@ wirelen_t get_net_wirelength(const Context *ctx, const NetInfo *net, float &tns)
} }
// Get the total wirelength for a cell // Get the total wirelength for a cell
wirelen_t get_cell_wirelength(const Context *ctx, const CellInfo *cell) wirelen_t get_cell_metric(const Context *ctx, const CellInfo *cell, MetricType type)
{ {
std::set<IdString> nets; std::set<IdString> nets;
for (auto p : cell->ports) { for (auto p : cell->ports) {
@ -86,16 +86,16 @@ wirelen_t get_cell_wirelength(const Context *ctx, const CellInfo *cell)
wirelen_t wirelength = 0; wirelen_t wirelength = 0;
float tns = 0; float tns = 0;
for (auto n : nets) { for (auto n : nets) {
wirelength += get_net_wirelength(ctx, ctx->nets.at(n).get(), tns); wirelength += get_net_metric(ctx, ctx->nets.at(n).get(), type, tns);
} }
return wirelength; return wirelength;
} }
wirelen_t get_cell_wirelength_at_bel(const Context *ctx, CellInfo *cell, BelId bel) wirelen_t get_cell_metric_at_bel(const Context *ctx, CellInfo *cell, BelId bel, MetricType type)
{ {
BelId oldBel = cell->bel; BelId oldBel = cell->bel;
cell->bel = bel; cell->bel = bel;
wirelen_t wirelen = get_cell_wirelength(ctx, cell); wirelen_t wirelen = get_cell_metric(ctx, cell, type);
cell->bel = oldBel; cell->bel = oldBel;
return wirelen; return wirelen;
} }
@ -118,7 +118,7 @@ bool place_single_cell(Context *ctx, CellInfo *cell, bool require_legality)
for (auto bel : ctx->getBels()) { for (auto bel : ctx->getBels()) {
if (ctx->getBelType(bel) == targetType && (!require_legality || ctx->isValidBelForCell(cell, bel))) { if (ctx->getBelType(bel) == targetType && (!require_legality || ctx->isValidBelForCell(cell, bel))) {
if (ctx->checkBelAvail(bel)) { if (ctx->checkBelAvail(bel)) {
wirelen_t wirelen = get_cell_wirelength_at_bel(ctx, cell, bel); wirelen_t wirelen = get_cell_metric_at_bel(ctx, cell, bel, MetricType::COST);
if (iters >= 4) if (iters >= 4)
wirelen += ctx->rng(25); wirelen += ctx->rng(25);
if (wirelen <= best_wirelen) { if (wirelen <= best_wirelen) {
@ -126,7 +126,7 @@ bool place_single_cell(Context *ctx, CellInfo *cell, bool require_legality)
best_bel = bel; best_bel = bel;
} }
} else { } else {
wirelen_t wirelen = get_cell_wirelength_at_bel(ctx, cell, bel); wirelen_t wirelen = get_cell_metric_at_bel(ctx, cell, bel, MetricType::COST);
if (iters >= 4) if (iters >= 4)
wirelen += ctx->rng(25); wirelen += ctx->rng(25);
if (wirelen <= best_ripup_wirelen) { if (wirelen <= best_ripup_wirelen) {

12
common/place_common.h
View File

@ -26,14 +26,20 @@ NEXTPNR_NAMESPACE_BEGIN
typedef int64_t wirelen_t; typedef int64_t wirelen_t;
enum class MetricType
{
COST,
WIRELENGTH
};
// Return the wirelength of a net // Return the wirelength of a net
wirelen_t get_net_wirelength(const Context *ctx, const NetInfo *net, float &tns); wirelen_t get_net_metric(const Context *ctx, const NetInfo *net, MetricType type, float &tns);
// Return the wirelength of all nets connected to a cell // Return the wirelength of all nets connected to a cell
wirelen_t get_cell_wirelength(const Context *ctx, const CellInfo *cell); wirelen_t get_cell_metric(const Context *ctx, const CellInfo *cell, MetricType type);
// Return the wirelength of all nets connected to a cell, when the cell is at a given bel // Return the wirelength of all nets connected to a cell, when the cell is at a given bel
wirelen_t get_cell_wirelength_at_bel(const Context *ctx, CellInfo *cell, BelId bel); wirelen_t get_cell_metric_at_bel(const Context *ctx, CellInfo *cell, BelId bel, MetricType type);
// Place a single cell in the lowest wirelength Bel available, optionally requiring validity check // Place a single cell in the lowest wirelength Bel available, optionally requiring validity check
bool place_single_cell(Context *ctx, CellInfo *cell, bool require_legality); bool place_single_cell(Context *ctx, CellInfo *cell, bool require_legality);

54
common/placer1.cc
View File

@ -135,17 +135,17 @@ class SAPlacer
log_info("Running simulated annealing placer.\n"); log_info("Running simulated annealing placer.\n");
// Calculate wirelength after initial placement // Calculate metric after initial placement
curr_wirelength = 0; curr_metric = 0;
curr_tns = 0; curr_tns = 0;
for (auto &net : ctx->nets) { for (auto &net : ctx->nets) {
wirelen_t wl = get_net_wirelength(ctx, net.second.get(), curr_tns); wirelen_t wl = get_net_metric(ctx, net.second.get(), MetricType::COST, curr_tns);
wirelengths[net.first] = wl; metrics[net.first] = wl;
curr_wirelength += wl; curr_metric += wl;
} }
int n_no_progress = 0; int n_no_progress = 0;
double avg_wirelength = curr_wirelength; double avg_metric = curr_metric;
temp = 10000; temp = 10000;
// Main simulated annealing loop // Main simulated annealing loop
@ -154,9 +154,9 @@ class SAPlacer
improved = false; improved = false;
if (iter % 5 == 0 || iter == 1) if (iter % 5 == 0 || iter == 1)
log_info(" at iteration #%d: temp = %f, wire length = " log_info(" at iteration #%d: temp = %f, cost = "
"%.0f, est tns = %.02fns\n", "%.0f, est tns = %.02fns\n",
iter, temp, double(curr_wirelength), curr_tns); iter, temp, double(curr_metric), curr_tns);
for (int m = 0; m < 15; ++m) { for (int m = 0; m < 15; ++m) {
// Loop through all automatically placed cells // Loop through all automatically placed cells
@ -177,7 +177,7 @@ class SAPlacer
if (temp <= 1e-3 && n_no_progress >= 5) { if (temp <= 1e-3 && n_no_progress >= 5) {
if (iter % 5 != 0) if (iter % 5 != 0)
log_info(" at iteration #%d: temp = %f, wire length = %f\n", iter, temp, double(curr_wirelength)); log_info(" at iteration #%d: temp = %f, cost = %f\n", iter, temp, double(curr_metric));
break; break;
} }
@ -187,8 +187,8 @@ class SAPlacer
double upper = 0.6, lower = 0.4; double upper = 0.6, lower = 0.4;
if (curr_wirelength < 0.95 * avg_wirelength) { if (curr_metric < 0.95 * avg_metric) {
avg_wirelength = 0.8 * avg_wirelength + 0.2 * curr_wirelength; avg_metric = 0.8 * avg_metric + 0.2 * curr_metric;
} else { } else {
if (Raccept >= 0.8) { if (Raccept >= 0.8) {
temp *= 0.7; temp *= 0.7;
@ -223,14 +223,14 @@ class SAPlacer
assign_budget(ctx); assign_budget(ctx);
} }
// Recalculate total wirelength entirely to avoid rounding errors // Recalculate total metric entirely to avoid rounding errors
// accumulating over time // accumulating over time
curr_wirelength = 0; curr_metric = 0;
curr_tns = 0; curr_tns = 0;
for (auto &net : ctx->nets) { for (auto &net : ctx->nets) {
wirelen_t wl = get_net_wirelength(ctx, net.second.get(), curr_tns); wirelen_t wl = get_net_metric(ctx, net.second.get(), MetricType::COST, curr_tns);
wirelengths[net.first] = wl; metrics[net.first] = wl;
curr_wirelength += wl; curr_metric += wl;
} }
} }
// Final post-pacement validitiy check // Final post-pacement validitiy check
@ -320,7 +320,7 @@ class SAPlacer
if (other_cell->belStrength > STRENGTH_WEAK) if (other_cell->belStrength > STRENGTH_WEAK)
return false; return false;
} }
wirelen_t new_wirelength = 0, delta; wirelen_t new_metric = 0, delta;
ctx->unbindBel(oldBel); ctx->unbindBel(oldBel);
if (other != IdString()) { if (other != IdString()) {
ctx->unbindBel(newBel); ctx->unbindBel(newBel);
@ -350,17 +350,17 @@ class SAPlacer
} }
} }
new_wirelength = curr_wirelength; new_metric = curr_metric;
// Recalculate wirelengths for all nets touched by the peturbation // Recalculate metrics for all nets touched by the peturbation
for (auto net : update) { for (auto net : update) {
new_wirelength -= wirelengths.at(net->name); new_metric -= metrics.at(net->name);
float temp_tns = 0; float temp_tns = 0;
wirelen_t net_new_wl = get_net_wirelength(ctx, net, temp_tns); wirelen_t net_new_wl = get_net_metric(ctx, net, MetricType::COST, temp_tns);
new_wirelength += net_new_wl; new_metric += net_new_wl;
new_lengths.push_back(std::make_pair(net->name, net_new_wl)); new_lengths.push_back(std::make_pair(net->name, net_new_wl));
} }
delta = new_wirelength - curr_wirelength; delta = new_metric - curr_metric;
n_move++; n_move++;
// SA acceptance criterea // SA acceptance criterea
if (delta < 0 || (temp > 1e-6 && (ctx->rng() / float(0x3fffffff)) <= std::exp(-delta / temp))) { if (delta < 0 || (temp > 1e-6 && (ctx->rng() / float(0x3fffffff)) <= std::exp(-delta / temp))) {
@ -373,9 +373,9 @@ class SAPlacer
ctx->unbindBel(newBel); ctx->unbindBel(newBel);
goto swap_fail; goto swap_fail;
} }
curr_wirelength = new_wirelength; curr_metric = new_metric;
for (auto new_wl : new_lengths) for (auto new_wl : new_lengths)
wirelengths.at(new_wl.first) = new_wl.second; metrics.at(new_wl.first) = new_wl.second;
return true; return true;
swap_fail: swap_fail:
@ -413,8 +413,8 @@ class SAPlacer
} }
Context *ctx; Context *ctx;
std::unordered_map<IdString, wirelen_t> wirelengths; std::unordered_map<IdString, wirelen_t> metrics;
wirelen_t curr_wirelength = std::numeric_limits<wirelen_t>::max(); wirelen_t curr_metric = std::numeric_limits<wirelen_t>::max();
float curr_tns = 0; float curr_tns = 0;
float temp = 1000; float temp = 1000;
bool improved = false; bool improved = false;

8
ice40/place_legaliser.cc
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@ -246,7 +246,7 @@ class PlacementLegaliser
std::tuple<int, int, int> find_closest_bel(float target_x, float target_y, CellChain &chain) std::tuple<int, int, int> find_closest_bel(float target_x, float target_y, CellChain &chain)
{ {
std::tuple<int, int, int> best_origin = std::make_tuple(-1, -1, -1); std::tuple<int, int, int> best_origin = std::make_tuple(-1, -1, -1);
wirelen_t best_wirelength = std::numeric_limits<wirelen_t>::max(); wirelen_t best_metric = std::numeric_limits<wirelen_t>::max();
int width = ctx->chip_info->width, height = ctx->chip_info->height; int width = ctx->chip_info->width, height = ctx->chip_info->height;
// Slow, should radiate outwards from target position - TODO // Slow, should radiate outwards from target position - TODO
int chain_size = int(chain.cells.size()); int chain_size = int(chain.cells.size());
@ -260,11 +260,11 @@ class PlacementLegaliser
valid = false; valid = false;
break; break;
} else { } else {
wirelen += get_cell_wirelength_at_bel(ctx, chain.cells.at(k), lb.first); wirelen += get_cell_metric_at_bel(ctx, chain.cells.at(k), lb.first, MetricType::COST);
} }
} }
if (valid && wirelen < best_wirelength) { if (valid && wirelen < best_metric) {
best_wirelength = wirelen; best_metric = wirelen;
best_origin = std::make_tuple(x, y, 0); best_origin = std::make_tuple(x, y, 0);
} }
} }