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ice40: Helper functions for placement legalisation

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Signed-off-by: David Shah <davey1576@gmail.com>
This commit is contained in:
David Shah 2018-06-25 13:52:44 +02:00
parent 28d8f8b2cb
commit fd8017449d
1 changed files with 40 additions and 2 deletions
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42
ice40/place_legaliser.cc
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@ -34,7 +34,7 @@ std::vector<std::vector<CellInfo *>> find_chains(const Context *ctx, F1 cell_typ
{
std::set<IdString> chained;
std::vector<std::vector<CellInfo *>> chains;
for (auto cell : ctx->cells) {
for (auto cell : sorted(ctx->cells)) {
if (chained.find(cell.first) != chained.end())
continue;
CellInfo *ci = cell.second;
@ -59,7 +59,45 @@ 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) {
float total_x = 0, total_y = 0;
int N = 0;
for (auto cell : chain) {
if (cell->bel == BelId())
continue;
int bel_x, bel_y;
bool bel_gb;
ctx->estimatePosition(cell->bel, bel_x, bel_y, bel_gb);
total_x += bel_x;
total_y += bel_y;
N++;
}
assert(N > 0);
x = total_x / N;
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;
}
bool legalise_design(Context *ctx)
{