diff options
| -rw-r--r-- | ice40/pack.cc | 49 |
1 files changed, 33 insertions, 16 deletions
diff --git a/ice40/pack.cc b/ice40/pack.cc index 6473fd8f..bcb84219 100644 --- a/ice40/pack.cc +++ b/ice40/pack.cc @@ -112,6 +112,18 @@ static void pack_nonlut_ffs(Context *ctx) } } +static bool net_is_constant(const Context *ctx, NetInfo *net, bool &value) +{ + if (net == nullptr) + return false; + if (net->name == ctx->id("$PACKER_GND_NET") || net->name == ctx->id("$PACKER_VCC_NET")) { + value = (net->name == ctx->id("$PACKER_VCC_NET")); + return true; + } else { + return false; + } +} + // Pack carry logic static void pack_carries(Context *ctx) { @@ -124,7 +136,15 @@ static void pack_carries(Context *ctx) CellInfo *ci = cell.second; if (is_carry(ctx, ci)) { packed_cells.insert(cell.first); - CellInfo *carry_ci_lc = net_only_drives(ctx, ci->ports.at(ctx->id("CI")).net, is_lc, ctx->id("I3"), false); + + CellInfo *carry_ci_lc; + bool ci_value; + bool ci_const = net_is_constant(ctx, ci->ports.at(ctx->id("CI")).net, ci_value); + if (ci_const) { + carry_ci_lc = nullptr; + } else { + carry_ci_lc = net_only_drives(ctx, ci->ports.at(ctx->id("CI")).net, is_lc, ctx->id("I3"), false); + } std::set<IdString> i0_matches, i1_matches; NetInfo *i0_net = ci->ports.at(ctx->id("I0")).net; @@ -157,20 +177,7 @@ static void pack_carries(Context *ctx) std::set_intersection(i0_matches.begin(), i0_matches.end(), i1_matches.begin(), i1_matches.end(), std::inserter(carry_lcs, carry_lcs.end())); CellInfo *carry_lc = nullptr; - if (carry_ci_lc) { - if (carry_lcs.find(carry_ci_lc->name) == carry_lcs.end()) { - if (ctx->verbose) { - for (auto i0 : i0_matches) - log_info("I0 candidate: '%s'\n", i0.c_str(ctx)); - for (auto i1 : i1_matches) - log_info("I1 candidate: '%s'\n", i1.c_str(ctx)); - log_info("I3 connects to: '%s'\n", carry_ci_lc->name.c_str(ctx)); - } - log_error("SB_CARRY '%s' cannot be packed into any logic " - "cell (I0 and I1 connections do not match I3 " - "connection)\n", - cell.first.c_str(ctx)); - } + if (carry_ci_lc && carry_lcs.find(carry_ci_lc->name) != carry_lcs.end()) { carry_lc = carry_ci_lc; } else { if (carry_lcs.empty()) { @@ -195,7 +202,17 @@ static void pack_carries(Context *ctx) new_cells.push_back(std::move(created_lc)); } else { - carry_lc = ctx->cells.at(*carry_lcs.begin()).get(); + IdString lc_name = *carry_lcs.begin(); + if (ctx->cells.find(lc_name) != ctx->cells.end()) { + carry_lc = ctx->cells.at(lc_name).get(); + } else { + // Name might not be found in the Context, if it is a new cell + auto new_pack = + std::find_if(new_cells.begin(), new_cells.end(), + [lc_name](std::unique_ptr<CellInfo> &nc) { return nc->name == lc_name; }); + assert(new_pack != new_cells.end()); + carry_lc = new_pack->get(); + } } } carry_lc->params[ctx->id("CARRY_ENABLE")] = "1"; |