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Merge pull request #525 from YosysHQ/dave/router2-tweaks

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router2: Improve thread safety
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David Shah 2020-12-01 10:22:42 +00:00 committed by GitHub
commit 62dde576e0
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1 changed files with 46 additions and 5 deletions
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51
common/router2.cc
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@ -85,6 +85,8 @@ struct Router2
bool unavailable = false;
// This wire has to be used for this net
int reserved_net = -1;
// The notional location of the wire, to guarantee thread safety
int16_t x = 0, y = 0;
// Visit data
struct
{
@ -200,6 +202,11 @@ struct Router2
if (bound->wires.at(wire).strength > STRENGTH_STRONG)
pwd.unavailable = true;
}
ArcBounds wire_loc = ctx->getRouteBoundingBox(wire, wire);
pwd.x = (wire_loc.x0 + wire_loc.x1) / 2;
pwd.y = (wire_loc.y0 + wire_loc.y1) / 2;
wire_to_idx[wire] = int(flat_wires.size());
flat_wires.push_back(pwd);
}
@ -254,8 +261,18 @@ struct Router2
std::queue<int> backwards_queue;
std::vector<int> dirty_wires;
// Thread bounding box
ArcBounds bb;
DeterministicRNG rng;
};
bool thread_test_wire(ThreadContext &t, PerWireData &w)
{
return w.x >= t.bb.x0 && w.x <= t.bb.x1 && w.y >= t.bb.y0 && w.y <= t.bb.y1;
}
enum ArcRouteResult
{
ARC_SUCCESS,
@ -530,6 +547,8 @@ struct Router2
continue;
if (wd.bound_nets.size() > 1 || (wd.bound_nets.size() == 1 && !wd.bound_nets.count(net->udata)))
continue; // never allow congestion in backwards routing
if (!thread_test_wire(t, wd))
continue; // thread safety issue
t.backwards_queue.push(next);
set_visited(t, next, uh, WireScore());
}
@ -615,6 +634,8 @@ struct Router2
continue;
if (nwd.bound_nets.count(net->udata) && nwd.bound_nets.at(net->udata).second != dh)
continue;
if (!thread_test_wire(t, nwd))
continue; // thread safety issue
WireScore next_score;
next_score.cost = curr.score.cost + score_wire_for_arc(net, i, next, dh);
next_score.delay =
@ -628,7 +649,7 @@ struct Router2
next_score.togo_cost);
#endif
// Add wire to queue if it meets criteria
t.queue.push(QueuedWire(next_idx, dh, ctx->getPipLocation(dh), next_score, ctx->rng()));
t.queue.push(QueuedWire(next_idx, dh, ctx->getPipLocation(dh), next_score, t.rng.rng()));
set_visited(t, next_idx, dh, next_score);
if (next == dst_wire) {
toexplore = std::min(toexplore, iter + 5);
@ -948,6 +969,8 @@ struct Router2
// Don't multithread if fewer than 200 nets (heuristic)
if (route_queue.size() < 200) {
ThreadContext st;
st.rng.rngseed(ctx->rng64());
st.bb = ArcBounds(0, 0, std::numeric_limits<int>::max(), std::numeric_limits<int>::max());
for (size_t j = 0; j < route_queue.size(); j++) {
route_net(st, nets_by_udata[route_queue[j]], false);
}
@ -956,14 +979,32 @@ struct Router2
const int Nq = 4, Nv = 2, Nh = 2;
const int N = Nq + Nv + Nh;
std::vector<ThreadContext> tcs(N + 1);
for (auto &th : tcs) {
th.rng.rngseed(ctx->rng64());
}
int le_x = mid_x - cfg.bb_margin_x;
int rs_x = mid_x + cfg.bb_margin_x;
int le_y = mid_y - cfg.bb_margin_y;
int rs_y = mid_y + cfg.bb_margin_y;
// Set up thread bounding boxes
tcs.at(0).bb = ArcBounds(0, 0, mid_x, mid_y);
tcs.at(1).bb = ArcBounds(mid_x + 1, 0, std::numeric_limits<int>::max(), le_y);
tcs.at(2).bb = ArcBounds(0, mid_y + 1, mid_x, std::numeric_limits<int>::max());
tcs.at(3).bb =
ArcBounds(mid_x + 1, mid_y + 1, std::numeric_limits<int>::max(), std::numeric_limits<int>::max());
tcs.at(4).bb = ArcBounds(0, 0, std::numeric_limits<int>::max(), mid_y);
tcs.at(5).bb = ArcBounds(0, mid_y + 1, std::numeric_limits<int>::max(), std::numeric_limits<int>::max());
tcs.at(6).bb = ArcBounds(0, 0, mid_x, std::numeric_limits<int>::max());
tcs.at(7).bb = ArcBounds(mid_x + 1, 0, std::numeric_limits<int>::max(), std::numeric_limits<int>::max());
tcs.at(8).bb = ArcBounds(0, 0, std::numeric_limits<int>::max(), std::numeric_limits<int>::max());
for (auto n : route_queue) {
auto &nd = nets.at(n);
auto ni = nets_by_udata.at(n);
int bin = N;
int le_x = mid_x - cfg.bb_margin_x;
int rs_x = mid_x + cfg.bb_margin_x;
int le_y = mid_y - cfg.bb_margin_y;
int rs_y = mid_y + cfg.bb_margin_y;
// Quadrants
if (nd.bb.x0 < le_x && nd.bb.x1 < le_x && nd.bb.y0 < le_y && nd.bb.y1 < le_y)
bin = 0;