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Merge pull request #48 from YosysHQ/placer_speedup

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placer: low hanging speedups
This commit is contained in:
Eddie Hung 2018-08-11 09:27:50 -07:00 committed by GitHub
commit 2e02f2d616
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GPG Key ID: 4AEE18F83AFDEB23
4 changed files with 66 additions and 32 deletions
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65
common/placer1.cc
View File

@ -70,6 +70,19 @@ class SAPlacer
fast_bels.at(type_idx).at(loc.x).at(loc.y).push_back(bel);
}
diameter = std::max(max_x, max_y) + 1;
costs.resize(ctx->nets.size());
old_udata.reserve(ctx->nets.size());
decltype(NetInfo::udata) n = 0;
for (auto &net : ctx->nets) {
old_udata.emplace_back(net.second->udata);
net.second->udata = n++;
}
}
~SAPlacer() {
for (auto &net : ctx->nets)
net.second->udata = old_udata[net.second->udata];
}
bool place()
@ -149,7 +162,7 @@ class SAPlacer
curr_tns = 0;
for (auto &net : ctx->nets) {
wirelen_t wl = get_net_metric(ctx, net.second.get(), MetricType::COST, curr_tns);
metrics[net.first] = wl;
costs[net.second->udata] = CostChange{wl, -1};
curr_metric += wl;
}
@ -250,7 +263,7 @@ class SAPlacer
curr_tns = 0;
for (auto &net : ctx->nets) {
wirelen_t wl = get_net_metric(ctx, net.second.get(), MetricType::COST, curr_tns);
metrics[net.first] = wl;
costs[net.second->udata] = CostChange{wl, -1};
curr_metric += wl;
}
@ -339,10 +352,8 @@ class SAPlacer
// Attempt a SA position swap, return true on success or false on failure
bool try_swap_position(CellInfo *cell, BelId newBel)
{
static std::unordered_set<NetInfo *> update;
static std::vector<std::pair<IdString, wirelen_t>> new_lengths;
new_lengths.clear();
update.clear();
static std::vector<NetInfo*> updates;
updates.clear();
BelId oldBel = cell->bel;
CellInfo *other_cell = ctx->getBoundBelCell(newBel);
if (other_cell != nullptr && other_cell->belStrength > STRENGTH_WEAK) {
@ -358,14 +369,23 @@ class SAPlacer
ctx->unbindBel(newBel);
}
for (const auto &port : cell->ports)
if (port.second.net != nullptr)
update.insert(port.second.net);
for (const auto &port : cell->ports) {
if (port.second.net != nullptr) {
auto &cost = costs[port.second.net->udata];
if (cost.new_cost == 0) continue;
cost.new_cost = 0;
updates.emplace_back(port.second.net);
}
}
if (other_cell != nullptr) {
for (const auto &port : other_cell->ports)
if (port.second.net != nullptr)
update.insert(port.second.net);
if (port.second.net != nullptr) {
auto &cost = costs[port.second.net->udata];
if (cost.new_cost == 0) continue;
cost.new_cost = 0;
updates.emplace_back(port.second.net);
}
}
ctx->bindBel(newBel, cell, STRENGTH_WEAK);
@ -383,12 +403,13 @@ class SAPlacer
new_metric = curr_metric;
// Recalculate metrics for all nets touched by the peturbation
for (auto net : update) {
new_metric -= metrics.at(net->name);
for (const auto &net : updates) {
auto &c = costs[net->udata];
new_metric -= c.curr_cost;
float temp_tns = 0;
wirelen_t net_new_wl = get_net_metric(ctx, net, MetricType::COST, temp_tns);
new_metric += net_new_wl;
new_lengths.push_back(std::make_pair(net->name, net_new_wl));
c.new_cost = net_new_wl;
}
new_dist = get_constraints_distance(ctx, cell);
@ -407,8 +428,10 @@ class SAPlacer
goto swap_fail;
}
curr_metric = new_metric;
for (auto new_wl : new_lengths)
metrics.at(new_wl.first) = new_wl.second;
for (const auto &net : updates) {
auto &c = costs[net->udata];
c = CostChange{c.new_cost, -1};
}
return true;
swap_fail:
@ -416,6 +439,8 @@ class SAPlacer
if (other_cell != nullptr) {
ctx->bindBel(newBel, other_cell, STRENGTH_WEAK);
}
for (const auto &net : updates)
costs[net->udata].new_cost = -1;
return false;
}
@ -444,7 +469,6 @@ class SAPlacer
}
Context *ctx;
std::unordered_map<IdString, wirelen_t> metrics;
wirelen_t curr_metric = std::numeric_limits<wirelen_t>::max();
float curr_tns = 0;
float temp = 1000;
@ -459,6 +483,13 @@ class SAPlacer
const float post_legalise_temp = 10;
const float post_legalise_dia_scale = 1.5;
Placer1Cfg cfg;
struct CostChange {
wirelen_t curr_cost;
wirelen_t new_cost;
};
std::vector<CostChange> costs;
std::vector<decltype(NetInfo::udata)> old_udata;
};
bool placer1(Context *ctx, Placer1Cfg cfg)

2
ice40/arch.h
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@ -812,7 +812,7 @@ struct Arch : BaseCtx
bool isBelLocationValid(BelId bel) const;
// Helper function for above
bool logicCellsCompatible(const std::vector<const CellInfo *> &cells) const;
bool logicCellsCompatible(const CellInfo** it, const size_t size) const;
// -------------------------------------------------
// Assign architecure-specific arguments to nets and cells, which must be

29
ice40/arch_place.cc
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@ -23,15 +23,17 @@
#include "nextpnr.h"
#include "util.h"
#include <boost/range/iterator_range.hpp>
NEXTPNR_NAMESPACE_BEGIN
bool Arch::logicCellsCompatible(const std::vector<const CellInfo *> &cells) const
bool Arch::logicCellsCompatible(const CellInfo** it, const size_t size) const
{
bool dffs_exist = false, dffs_neg = false;
const NetInfo *cen = nullptr, *clk = nullptr, *sr = nullptr;
int locals_count = 0;
for (auto cell : cells) {
for (auto cell : boost::make_iterator_range(it, it+size)) {
NPNR_ASSERT(cell->belType == id_ICESTORM_LC);
if (cell->lcInfo.dffEnable) {
if (!dffs_exist) {
@ -71,15 +73,15 @@ bool Arch::logicCellsCompatible(const std::vector<const CellInfo *> &cells) cons
bool Arch::isBelLocationValid(BelId bel) const
{
if (getBelType(bel) == id_ICESTORM_LC) {
std::vector<const CellInfo *> bel_cells;
std::array<const CellInfo *, 8> bel_cells;
size_t num_cells = 0;
Loc bel_loc = getBelLocation(bel);
for (auto bel_other : getBelsByTile(bel_loc.x, bel_loc.y)) {
CellInfo *ci_other = getBoundBelCell(bel_other);
if (ci_other != nullptr) {
bel_cells.push_back(ci_other);
}
if (ci_other != nullptr)
bel_cells[num_cells++] = ci_other;
}
return logicCellsCompatible(bel_cells);
return logicCellsCompatible(bel_cells.data(), num_cells);
} else {
CellInfo *ci = getBoundBelCell(bel);
if (ci == nullptr)
@ -94,17 +96,18 @@ bool Arch::isValidBelForCell(CellInfo *cell, BelId bel) const
if (cell->type == id_ICESTORM_LC) {
NPNR_ASSERT(getBelType(bel) == id_ICESTORM_LC);
std::vector<const CellInfo *> bel_cells;
std::array<const CellInfo *, 8> bel_cells;
size_t num_cells = 0;
Loc bel_loc = getBelLocation(bel);
for (auto bel_other : getBelsByTile(bel_loc.x, bel_loc.y)) {
CellInfo *ci_other = getBoundBelCell(bel_other);
if (ci_other != nullptr && bel_other != bel) {
bel_cells.push_back(ci_other);
}
if (ci_other != nullptr && bel_other != bel)
bel_cells[num_cells++] = ci_other;
}
bel_cells.push_back(cell);
return logicCellsCompatible(bel_cells);
bel_cells[num_cells++] = cell;
return logicCellsCompatible(bel_cells.data(), num_cells);
} else if (cell->type == id_SB_IO) {
// Do not allow placement of input SB_IOs on blocks where there a PLL is outputting to.

2
ice40/chains.cc
View File

@ -97,7 +97,7 @@ class ChainConstrainer
}
tile.push_back(cell);
chains.back().cells.push_back(cell);
bool split_chain = (!ctx->logicCellsCompatible(tile)) || (int(chains.back().cells.size()) > max_length);
bool split_chain = (!ctx->logicCellsCompatible(tile.data(), tile.size())) || (int(chains.back().cells.size()) > max_length);
if (split_chain) {
CellInfo *passout = make_carry_pass_out(cell->ports.at(ctx->id("COUT")));
tile.pop_back();