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Fixing packing of carry cells

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Signed-off-by: David Shah <davey1576@gmail.com>
This commit is contained in:
David Shah 2018-06-26 14:37:01 +02:00
parent 2073403f41
commit 29df577f14
2 changed files with 49 additions and 24 deletions
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2
ice40/carry_tests/test.sh
View File

@ -2,7 +2,7 @@
set -ex
NAME=${1%.v}
yosys -p "synth_ice40 -top top; write_json ${NAME}.json" $1
../../nextpnr-ice40 --json ${NAME}.json --pcf test.pcf --asc ${NAME}.asc
../../nextpnr-ice40 --json ${NAME}.json --pcf test.pcf --asc ${NAME}.asc --verbose
icebox_vlog -p test.pcf ${NAME}.asc > ${NAME}_out.v
yosys -p "read_verilog +/ice40/cells_sim.v;\

59
ice40/pack.cc
View File

@ -125,33 +125,53 @@ static void pack_carries(Context *ctx)
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);
if (!ci->ports.at(ctx->id("I0")).net)
log_error("SB_CARRY '%s' has disconnected port I0\n", cell.first.c_str(ctx));
if (!ci->ports.at(ctx->id("I1")).net)
log_error("SB_CARRY '%s' has disconnected port I1\n", cell.first.c_str(ctx));
std::unordered_set<IdString> i0_matches, i1_matches;
auto &i0_usrs = ci->ports.at(ctx->id("I0")).net->users;
auto &i1_usrs = ci->ports.at(ctx->id("I1")).net->users;
std::set<IdString> i0_matches, i1_matches;
NetInfo *i0_net = ci->ports.at(ctx->id("I0")).net;
NetInfo *i1_net = ci->ports.at(ctx->id("I1")).net;
// Find logic cells connected to both I0 and I1
for (auto usr : i0_usrs) {
if (is_lc(ctx, usr.cell) && usr.port == ctx->id("I1"))
if (i0_net) {
for (auto usr : i0_net->users) {
if (is_lc(ctx, usr.cell) && usr.port == ctx->id("I1")) {
i0_matches.insert(usr.cell->name);
}
for (auto usr : i1_usrs) {
if (is_lc(ctx, usr.cell) && usr.port == ctx->id("I2"))
if (!i1_net) {
// I1 is don't care when disconnected, duplicate I0
i1_matches.insert(usr.cell->name);
}
}
}
}
if (i1_net) {
for (auto usr : i1_net->users) {
if (is_lc(ctx, usr.cell) && usr.port == ctx->id("I2")) {
i1_matches.insert(usr.cell->name);
if (!i0_net) {
// I0 is don't care when disconnected, duplicate I1
i0_matches.insert(usr.cell->name);
}
}
}
}
std::set<IdString> carry_lcs;
std::set_intersection(i0_matches.begin(), i0_matches.end(), i1_matches.begin(), i1_matches.end(),
std::inserter(carry_lcs, carry_lcs.begin()));
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 (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));
}
carry_lc = carry_ci_lc;
} else {
if (carry_lcs.empty()) {
@ -167,14 +187,19 @@ static void pack_carries(Context *ctx)
carry_lc->attrs[ctx->id("CARRY_ENABLE")] = "1";
replace_port(ci, ctx->id("CI"), carry_lc, ctx->id("CIN"));
replace_port(ci, ctx->id("CO"), carry_lc, ctx->id("COUT"));
if (i0_net) {
auto &i0_usrs = i0_net->users;
i0_usrs.erase(std::remove_if(i0_usrs.begin(), i0_usrs.end(), [ci, ctx](const PortRef &pr) {
return pr.cell == ci && pr.port == ctx->id("I0");
}));
}
if (i1_net) {
auto &i1_usrs = i1_net->users;
i1_usrs.erase(std::remove_if(i1_usrs.begin(), i1_usrs.end(), [ci, ctx](const PortRef &pr) {
return pr.cell == ci && pr.port == ctx->id("I1");
}));
}
// Check for constant driver on CIN
if (carry_lc->ports.at(ctx->id("CIN")).net != nullptr) {
IdString cin_net = carry_lc->ports.at(ctx->id("CIN")).net->name;
@ -250,7 +275,7 @@ static void set_net_constant(const Context *ctx, NetInfo *orig, NetInfo *constne
CellInfo *uc = user.cell;
if (ctx->verbose)
log_info("%s user %s\n", orig->name.c_str(ctx), uc->name.c_str(ctx));
if ((is_lut(ctx, uc) || is_lc(ctx, uc)) && (user.port.str(ctx).at(0) == 'I') && !constval) {
if ((is_lut(ctx, uc) || is_lc(ctx, uc) || is_carry(ctx, uc)) && (user.port.str(ctx).at(0) == 'I') && !constval) {
uc->ports[user.port].net = nullptr;
} else {
uc->ports[user.port].net = constnet;