diff options
Diffstat (limited to 'common/place_sa.cc')
| -rw-r--r-- | common/place_sa.cc | 102 |
1 files changed, 72 insertions, 30 deletions
diff --git a/common/place_sa.cc b/common/place_sa.cc index 2b8b960b..058f0a84 100644 --- a/common/place_sa.cc +++ b/common/place_sa.cc @@ -30,7 +30,6 @@ #include <map> #include <ostream> #include <queue> -#include <random> #include <set> #include <stdarg.h> #include <stdio.h> @@ -42,6 +41,8 @@ NEXTPNR_NAMESPACE_BEGIN +typedef int64_t wirelen_t; + class SAPlacer { public: @@ -76,6 +77,8 @@ class SAPlacer bool place() { + log_break(); + size_t placed_cells = 0; // Initial constraints placer for (auto cell_entry : ctx->cells) { @@ -143,9 +146,10 @@ class SAPlacer // Calculate wirelength after initial placement curr_wirelength = 0; + curr_tns = 0; for (auto net : ctx->nets) { - float wl = get_wirelength(net.second); - wirelengths[net.second] = wl; + wirelen_t wl = get_wirelength(net.second, curr_tns); + wirelengths[net.first] = wl; curr_wirelength += wl; } @@ -159,8 +163,9 @@ class SAPlacer improved = false; if (iter % 5 == 0 || iter == 1) - log_info(" at iteration #%d: temp = %f, wire length = %f\n", - iter, temp, curr_wirelength); + log_info(" at iteration #%d: temp = %f, wire length = " + "%.0f, est tns = %.02fns\n", + iter, temp, double(curr_wirelength), curr_tns); for (int m = 0; m < 15; ++m) { // Loop through all automatically placed cells @@ -183,7 +188,7 @@ class SAPlacer if (iter % 5 != 0) log_info( " at iteration #%d: temp = %f, wire length = %f\n", - iter, temp, curr_wirelength); + iter, temp, double(curr_wirelength)); break; } @@ -213,6 +218,16 @@ class SAPlacer temp *= 0.8; } } + + // Recalculate total wirelength entirely to avoid rounding errors + // accumulating over time + curr_wirelength = 0; + curr_tns = 0; + for (auto net : ctx->nets) { + wirelen_t wl = get_wirelength(net.second, curr_tns); + wirelengths[net.first] = wl; + curr_wirelength += wl; + } } // Final post-pacement validitiy check for (auto bel : ctx->getBels()) { @@ -221,9 +236,17 @@ class SAPlacer std::string cell_text = "no cell"; if (cell != IdString()) cell_text = std::string("cell '") + cell.str(ctx) + "'"; - log_error("post-placement validity check failed for Bel '%s' " - "(%s)", - ctx->getBelName(bel).c_str(ctx), cell_text.c_str()); + if (ctx->force) { + log_warning( + "post-placement validity check failed for Bel '%s' " + "(%s)\n", + ctx->getBelName(bel).c_str(ctx), cell_text.c_str()); + } else { + log_error( + "post-placement validity check failed for Bel '%s' " + "(%s)\n", + ctx->getBelName(bel).c_str(ctx), cell_text.c_str()); + } } } return true; @@ -288,9 +311,9 @@ class SAPlacer } // Get the total estimated wirelength for a net - float get_wirelength(NetInfo *net) + wirelen_t get_wirelength(NetInfo *net, float &tns) { - float wirelength = 0; + wirelen_t wirelength = 0; int driver_x, driver_y; bool driver_gb; CellInfo *driver_cell = net->driver.cell; @@ -303,24 +326,36 @@ class SAPlacer driver_cell->bel, ctx->portPinFromId(net->driver.port)); if (driver_gb) return 0; + float worst_slack = 1000; + int xmin = driver_x, xmax = driver_x, ymin = driver_y, ymax = driver_y; for (auto load : net->users) { if (load.cell == nullptr) continue; CellInfo *load_cell = load.cell; if (load_cell->bel == BelId()) continue; - // ctx->estimatePosition(load_cell->bel, load_x, load_y, load_gb); + WireId user_wire = ctx->getWireBelPin( load_cell->bel, ctx->portPinFromId(load.port)); - // wirelength += std::abs(load_x - driver_x) + std::abs(load_y - - // driver_y); delay_t raw_wl = ctx->estimateDelay(drv_wire, user_wire); - wirelength += pow(1.3, (ctx->getDelayNS(raw_wl) - - ctx->getDelayNS(load.budget)) / - 10) + - ctx->getDelayNS(raw_wl); - // wirelength += pow(ctx->estimateDelay(drv_wire, user_wire), 2.0); + float slack = + ctx->getDelayNS(load.budget) - ctx->getDelayNS(raw_wl); + if (slack < 0) + tns += slack; + worst_slack = std::min(slack, worst_slack); + int load_x, load_y; + bool load_gb; + ctx->estimatePosition(load_cell->bel, load_x, load_y, load_gb); + if (load_gb) + continue; + xmin = std::min(xmin, load_x); + ymin = std::min(ymin, load_y); + xmax = std::max(xmax, load_x); + ymax = std::max(ymax, load_y); } + wirelength = + wirelen_t((((ymax - ymin) + (xmax - xmin)) * + std::min(5.0, (1.0 + std::exp(-worst_slack / 5))))); return wirelength; } @@ -328,13 +363,13 @@ class SAPlacer bool try_swap_position(CellInfo *cell, BelId newBel) { static std::unordered_set<NetInfo *> update; - static std::vector<std::pair<NetInfo *, float>> new_lengths; + static std::vector<std::pair<IdString, wirelen_t>> new_lengths; new_lengths.clear(); update.clear(); BelId oldBel = cell->bel; IdString other = ctx->getBelCell(newBel, true); CellInfo *other_cell = nullptr; - float new_wirelength = 0, delta; + wirelen_t new_wirelength = 0, delta; ctx->unbindBel(oldBel); if (other != IdString()) { other_cell = ctx->cells[other]; @@ -373,10 +408,11 @@ class SAPlacer // Recalculate wirelengths for all nets touched by the peturbation for (auto net : update) { - new_wirelength -= wirelengths.at(net); - float net_new_wl = get_wirelength(net); + new_wirelength -= wirelengths.at(net->name); + float temp_tns = 0; + wirelen_t net_new_wl = get_wirelength(net, temp_tns); new_wirelength += net_new_wl; - new_lengths.push_back(std::make_pair(net, net_new_wl)); + new_lengths.push_back(std::make_pair(net->name, net_new_wl)); } delta = new_wirelength - curr_wirelength; n_move++; @@ -384,7 +420,7 @@ class SAPlacer if (delta < 0 || (temp > 1e-6 && (ctx->rng() / float(0x3fffffff)) <= std::exp(-delta / temp))) { n_accept++; - if (delta < 0) + if (delta < 2) improved = true; } else { if (other != IdString()) @@ -434,8 +470,9 @@ class SAPlacer } Context *ctx; - std::unordered_map<NetInfo *, float> wirelengths; - float curr_wirelength = std::numeric_limits<float>::infinity(); + std::unordered_map<IdString, wirelen_t> wirelengths; + wirelen_t curr_wirelength = std::numeric_limits<wirelen_t>::max(); + float curr_tns = 0; float temp = 1000; bool improved = false; int n_move, n_accept; @@ -448,9 +485,14 @@ class SAPlacer bool place_design_sa(Context *ctx) { - SAPlacer placer(ctx); - placer.place(); - return true; + try { + SAPlacer placer(ctx); + placer.place(); + log_info("Checksum: 0x%08x\n", ctx->checksum()); + return true; + } catch (log_execution_error_exception) { + return false; + } } NEXTPNR_NAMESPACE_END |