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-rw-r--r--ecp5/arch.cc2
-rw-r--r--ecp5/pack.cc58
2 files changed, 59 insertions, 1 deletions
diff --git a/ecp5/arch.cc b/ecp5/arch.cc
index fdc9c8fc..cd5fa0cb 100644
--- a/ecp5/arch.cc
+++ b/ecp5/arch.cc
@@ -457,7 +457,7 @@ delay_t Arch::estimateDelay(WireId src, WireId dst) const
int dx = abs(src_loc.first - dst_loc.first), dy = abs(src_loc.second - dst_loc.second);
return (130 - 25 * args.speed) *
- (8 + std::max(dx - 5, 0) + std::max(dy - 5, 0) + 2 * (std::min(dx, 5) + std::min(dy, 5)));
+ (6 + std::max(dx - 5, 0) + std::max(dy - 5, 0) + 2 * (std::min(dx, 5) + std::min(dy, 5)));
}
delay_t Arch::predictDelay(const NetInfo *net_info, const PortRef &sink) const
diff --git a/ecp5/pack.cc b/ecp5/pack.cc
index b05aec71..9f987f35 100644
--- a/ecp5/pack.cc
+++ b/ecp5/pack.cc
@@ -165,6 +165,7 @@ class Ecp5Packer
CellInfo *ci = cell.second;
if (is_lut(ctx, ci) && procdLuts.find(cell.first) == procdLuts.end()) {
NetInfo *znet = ci->ports.at(ctx->id("Z")).net;
+ std::vector<NetInfo *> inpnets;
if (znet != nullptr) {
for (auto user : znet->users) {
if (is_lut(ctx, user.cell) && user.cell != ci &&
@@ -229,14 +230,71 @@ class Ecp5Packer
}
}
}
+
+ // Pack LUTs feeding the same CCU2, RAM or DFF into a SLICE
+ if (znet != nullptr && znet->users.size() < 10) {
+ for (auto user : znet->users) {
+ if (is_lc(ctx, user.cell) || user.cell->type == ctx->id("DP16KD") || is_ff(ctx, user.cell)) {
+ for (auto port : user.cell->ports) {
+ if (port.second.type != PORT_IN || port.second.net == nullptr || port.second.net == znet)
+ continue;
+ if (port.second.net->users.size() > 10)
+ continue;
+ CellInfo *drv = port.second.net->driver.cell;
+ if (drv == nullptr)
+ continue;
+ if (is_lut(ctx, drv) && !procdLuts.count(drv->name) && can_pack_lutff(ci->name, drv->name)) {
+ procdLuts.insert(ci->name);
+ procdLuts.insert(drv->name);
+ lutPairs[ci->name] = drv->name;
+ goto paired_inlut;
+ }
+
+ }
+ }
+ }
+ }
+
+ // Pack LUTs sharing an input with a simple fanout-based heuristic
+ for (const char *inp : {"A", "B", "C", "D"}) {
+ NetInfo *innet = ci->ports.at(ctx->id(inp)).net;
+ if (innet != nullptr && innet->users.size() < 5 && innet->users.size() > 1)
+ inpnets.push_back(innet);
+ }
+ std::sort(inpnets.begin(), inpnets.end(), [&](const NetInfo *a, const NetInfo *b) {
+ return a->users.size() < b->users.size();
+ });
+ for (auto inet : inpnets) {
+ for (auto &user : inet->users) {
+ if (user.cell == nullptr || user.cell == ci || !is_lut(ctx, user.cell))
+ continue;
+ if (procdLuts.count(user.cell->name))
+ continue;
+ if (can_pack_lutff(ci->name, user.cell->name)) {
+ procdLuts.insert(ci->name);
+ procdLuts.insert(user.cell->name);
+ lutPairs[ci->name] = user.cell->name;
+ goto paired_inlut;
+ }
+
+ }
+ }
+
if (false) {
paired_inlut:
continue;
}
}
}
+ if (ctx->debug) {
+ log_info("Singleton LUTs (packer QoR debug): \n");
+ for (auto cell : sorted(ctx->cells))
+ if (is_lut(ctx, cell.second) && !procdLuts.count(cell.first))
+ log_info(" %s\n", cell.first.c_str(ctx));
+ }
}
+
// Return true if an port is a top level port that provides its own IOBUF
bool is_top_port(PortRef &port)
{