diff options
-rw-r--r-- | ice40/cells.cc | 2 | ||||
-rw-r--r-- | ice40/place_legaliser.cc | 108 |
2 files changed, 80 insertions, 30 deletions
diff --git a/ice40/cells.cc b/ice40/cells.cc index ddb69f4f..e9c75649 100644 --- a/ice40/cells.cc +++ b/ice40/cells.cc @@ -47,6 +47,8 @@ CellInfo *create_ice_cell(Context *ctx, IdString type, std::string name) new_cell->params[ctx->id("DFF_ENABLE")] = "0"; new_cell->params[ctx->id("SET_NORESET")] = "0"; new_cell->params[ctx->id("ASYNC_SR")] = "0"; + new_cell->params[ctx->id("CIN_CONST")] = "0"; + new_cell->params[ctx->id("CIN_SET")] = "0"; add_port(ctx, new_cell, "I0", PORT_IN); add_port(ctx, new_cell, "I1", PORT_IN); diff --git a/ice40/place_legaliser.cc b/ice40/place_legaliser.cc index 83316d6e..a4e8da0c 100644 --- a/ice40/place_legaliser.cc +++ b/ice40/place_legaliser.cc @@ -61,7 +61,8 @@ std::vector<std::vector<CellInfo *>> find_chains(const Context *ctx, F1 cell_typ return chains; } -static void get_chain_midpoint(const Context *ctx, const std::vector<CellInfo *> &chain, float &x, float &y) { +static void get_chain_midpoint(const Context *ctx, const std::vector<CellInfo *> &chain, float &x, float &y) +{ float total_x = 0, total_y = 0; int N = 0; for (auto cell : chain) { @@ -79,38 +80,85 @@ static void get_chain_midpoint(const Context *ctx, const std::vector<CellInfo *> y = total_y / N; } -static CellInfo *make_carry_pass_out(Context *ctx, PortInfo &cout_port) { - assert(cout_port.net != nullptr); - CellInfo *lc = create_ice_cell(ctx, ctx->id("ICESTORM_LC")); - lc->params[ctx->id("LUT_INIT")] = "65280"; // 0xff00: O = I3 - lc->ports.at(ctx->id("O")).net = cout_port.net; - NetInfo *co_i3_net = new NetInfo(); - co_i3_net->name = ctx->id(lc->name.str(ctx) + "$I3"); - co_i3_net->driver = cout_port.net->driver; - PortRef i3_r; - i3_r.port = ctx->id("I3"); - i3_r.cell = lc; - co_i3_net->users.push_back(i3_r); - PortRef o_r; - o_r.port = ctx->id("O"); - o_r.cell = lc; - cout_port.net->driver = o_r; - lc->ports.at(ctx->id("I3")).net = co_i3_net; - return lc; -} +class PlacementLegaliser +{ + public: + PlacementLegaliser(Context *ctx) : ctx(ctx){}; + bool legalise() + { + bool legalised_carries = legalise_carries(); + if (!legalised_carries && !ctx->force) + return false; + return legalised_carries; + } + + private: + bool legalise_carries() + { + std::vector<std::vector<CellInfo *>> carry_chains = find_chains( + ctx, is_lc, + [](const Context *ctx, const CellInfo *cell) { + return net_driven_by(ctx, cell->ports.at(ctx->id("CIN")).net, is_lc, ctx->id("COUT")); + }, + [](const Context *ctx, const CellInfo *cell) { + return net_only_drives(ctx, cell->ports.at(ctx->id("COUT")).net, is_lc, ctx->id("CIN"), false); + }); + // TODO + return true; + } + + CellInfo *make_carry_pass_out(PortInfo &cout_port) + { + assert(cout_port.net != nullptr); + CellInfo *lc = create_ice_cell(ctx, ctx->id("ICESTORM_LC")); + lc->params[ctx->id("LUT_INIT")] = "65280"; // 0xff00: O = I3 + lc->ports.at(ctx->id("O")).net = cout_port.net; + NetInfo *co_i3_net = new NetInfo(); + co_i3_net->name = ctx->id(lc->name.str(ctx) + "$I3"); + co_i3_net->driver = cout_port.net->driver; + PortRef i3_r; + i3_r.port = ctx->id("I3"); + i3_r.cell = lc; + co_i3_net->users.push_back(i3_r); + PortRef o_r; + o_r.port = ctx->id("O"); + o_r.cell = lc; + cout_port.net->driver = o_r; + lc->ports.at(ctx->id("I3")).net = co_i3_net; + ctx->cells[lc->name] = lc; + createdCells.insert(lc->name); + return lc; + } + + CellInfo *make_carry_feed_in(CellInfo *cin_cell, PortInfo &cin_port) + { + assert(cin_port.net != nullptr); + CellInfo *lc = create_ice_cell(ctx, ctx->id("ICESTORM_LC")); + lc->params[ctx->id("CARRY_ENABLE")] = "1"; + lc->params[ctx->id("CIN_CONST")] = "1"; + lc->params[ctx->id("CIN_SET")] = "1"; + lc->ports.at(ctx->id("I1")).net = cin_port.net; + cin_port.net->users.erase(std::remove_if(cin_port.net->users.begin(), cin_port.net->users.end(), + [cin_cell, cin_port](const PortRef &usr) { + return usr.cell == cin_cell && usr.port == cin_port.name; + })); + NetInfo *out_net = new NetInfo(); + out_net->name = ctx->id(lc->name.str(ctx) + "$O"); + + ctx->cells[lc->name] = lc; + createdCells.insert(lc->name); + return lc; + } + + Context *ctx; + std::unordered_set<IdString> rippedCells; + std::unordered_set<IdString> createdCells; +}; bool legalise_design(Context *ctx) { - std::vector<std::vector<CellInfo *>> carry_chains = find_chains( - ctx, is_lc, - [](const Context *ctx, const CellInfo *cell) { - return net_driven_by(ctx, cell->ports.at(ctx->id("CIN")).net, is_lc, ctx->id("COUT")); - }, - [](const Context *ctx, const CellInfo *cell) { - return net_only_drives(ctx, cell->ports.at(ctx->id("COUT")).net, is_lc, ctx->id("CIN"), false); - }); - // TODO - return true; + PlacementLegaliser lg(ctx); + return lg.legalise(); } NEXTPNR_NAMESPACE_END |