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author | David Shah <davey1576@gmail.com> | 2018-06-15 09:27:02 +0200 |
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committer | David Shah <davey1576@gmail.com> | 2018-06-16 14:44:10 +0200 |
commit | 104c2dad9b4148586b05d41e482101a925cf681f (patch) | |
tree | 3a2800b8e574520a259cd903ef1646babfb254b6 | |
parent | 828c96f80ba4695d39ade82a5431b01a84fcec76 (diff) | |
download | nextpnr-104c2dad9b4148586b05d41e482101a925cf681f.tar.gz nextpnr-104c2dad9b4148586b05d41e482101a925cf681f.tar.bz2 nextpnr-104c2dad9b4148586b05d41e482101a925cf681f.zip |
Adding randomness and changes metrics to placer
Signed-off-by: David Shah <davey1576@gmail.com>
-rw-r--r-- | common/place.cc | 34 |
1 files changed, 25 insertions, 9 deletions
diff --git a/common/place.cc b/common/place.cc index 15455834..35299604 100644 --- a/common/place.cc +++ b/common/place.cc @@ -31,6 +31,8 @@ #include <stdlib.h> #include <string.h> #include <vector> +#include <random> +#include <algorithm> #include "arch_place.h" #include "log.h" @@ -124,9 +126,9 @@ void place_design(Design *design) } } -static void place_cell(Design *design, CellInfo *cell) +static void place_cell(Design *design, CellInfo *cell, std::mt19937 &rnd) { - + std::uniform_real_distribution<float> random_wirelength(0.0, 30.0); float best_distance = std::numeric_limits<float>::infinity(); BelId best_bel = BelId(); Chip &chip = design->chip; @@ -140,16 +142,21 @@ static void place_cell(Design *design, CellInfo *cell) isValidBelForCell(design, cell, bel)) { float distance = 0; float belx, bely; + bool has_conns = false; chip.estimatePosition(bel, belx, bely); for (auto port : cell->ports) { const PortInfo &pi = port.second; if (pi.net != nullptr) { CellInfo *drv = pi.net->driver.cell; + float pin_wirelength = std::numeric_limits<float>::infinity(); if (drv != nullptr && drv->bel != BelId()) { float otherx, othery; chip.estimatePosition(drv->bel, otherx, othery); - distance += std::abs(belx - otherx) + + float local_wl = std::abs(belx - otherx) + std::abs(bely - othery); + if (local_wl < pin_wirelength) + pin_wirelength = local_wl; + has_conns = true; } if (pi.net->users.size() < 5) { for (auto user : pi.net->users) { @@ -157,13 +164,20 @@ static void place_cell(Design *design, CellInfo *cell) if (uc != nullptr && uc->bel != BelId()) { float otherx, othery; chip.estimatePosition(uc->bel, otherx, othery); - distance += std::abs(belx - otherx) + + float local_wl = std::abs(belx - otherx) + std::abs(bely - othery); + if (local_wl < pin_wirelength) + pin_wirelength = local_wl; + has_conns = true; } } } + if (!std::isinf(pin_wirelength)) + distance += pin_wirelength; } } + if (!has_conns) + distance = random_wirelength(rnd); if (distance <= best_distance) { best_distance = distance; best_bel = bel; @@ -213,21 +227,23 @@ void place_design_heuristic(Design *design) } } log_info("place_constraints placed %d\n", placed_cells); - std::unordered_set<IdString> autoplaced; + std::mt19937 rnd; + std::vector<IdString> autoplaced; for (auto cell : design->cells) { CellInfo *ci = cell.second; if (ci->bel == BelId()) { - place_cell(design, ci); - autoplaced.insert(cell.first); + place_cell(design, ci, rnd); + autoplaced.push_back(cell.first); placed_cells++; } log_info("placed %d/%d\n", placed_cells, total_cells); } - for (int i = 0 ; i < 3; i ++) { + for (int i = 0 ; i < 2; i ++) { int replaced_cells = 0; + std::shuffle(autoplaced.begin(), autoplaced.end(), rnd); for (auto cell : autoplaced) { CellInfo *ci = design->cells[cell]; - place_cell(design, ci); + place_cell(design, ci, rnd); replaced_cells++; log_info("replaced %d/%d\n", replaced_cells, autoplaced.size()); } |