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-rw-r--r--ecp5/pack.cc112
1 files changed, 96 insertions, 16 deletions
diff --git a/ecp5/pack.cc b/ecp5/pack.cc
index e2bc3875..d2c0085b 100644
--- a/ecp5/pack.cc
+++ b/ecp5/pack.cc
@@ -22,6 +22,7 @@
#include <iterator>
#include <unordered_set>
#include "cells.h"
+#include "chain_utils.h"
#include "design_utils.h"
#include "log.h"
#include "util.h"
@@ -106,6 +107,26 @@ class Ecp5Packer
return true;
}
+ // Return whether or not an FF can be added to a tile (pairing checks must also be done using the fn above)
+ bool can_add_ff_to_file(const std::vector<CellInfo *> &tile_ffs, CellInfo *ff0) {
+ for (const auto &existing : tile_ffs) {
+ if (net_or_nullptr(existing, ctx->id("CLK")) != net_or_nullptr(ff0, ctx->id("CLK")))
+ return false;
+ if (net_or_nullptr(existing, ctx->id("LSR")) != net_or_nullptr(ff0, ctx->id("LSR")))
+ return false;
+ if (str_or_default(existing->params, ctx->id("CLKMUX"), "CLK") !=
+ str_or_default(ff0->params, ctx->id("CLKMUX"), "CLK"))
+ return false;
+ if (str_or_default(existing->params, ctx->id("LSRMUX"), "LSR") !=
+ str_or_default(ff0->params, ctx->id("LSRMUX"), "LSR"))
+ return false;
+ if (str_or_default(existing->params, ctx->id("LSRMUX"), "LSR") !=
+ str_or_default(ff0->params, ctx->id("LSRMUX"), "LSR"))
+ return false;
+ }
+ return true;
+ }
+
// Return true if two LUTs can be paired considering FF compatibility
bool can_pack_lutff(IdString lut0, IdString lut1)
{
@@ -315,11 +336,10 @@ class Ecp5Packer
// Create a feed in to the carry chain
CellInfo *make_carry_feed_in(NetInfo *carry, PortRef chain_in)
{
- std::unique_ptr<CellInfo> feedin = create_ecp5_cell(ctx, ctx->id("TRELLIS_SLICE"));
+ std::unique_ptr<CellInfo> feedin = create_ecp5_cell(ctx, ctx->id("CCU2C"));
- feedin->params[ctx->id("MODE")] = "CCU2";
- feedin->params[ctx->id("LUT0_INITVAL")] = "10"; // LUT4 = 0; LUT2 = A
- feedin->params[ctx->id("LUT1_INITVAL")] = "65535";
+ feedin->params[ctx->id("INIT0")] = "10"; // LUT4 = 0; LUT2 = A
+ feedin->params[ctx->id("INIT1")] = "65535";
feedin->params[ctx->id("INJECT1_0")] = "NO";
feedin->params[ctx->id("INJECT1_1")] = "YES";
@@ -331,8 +351,8 @@ class Ecp5Packer
connect_port(ctx, carry, feedin.get(), id_A0);
std::unique_ptr<NetInfo> new_carry(new NetInfo());
- new_carry->name = ctx->id(feedin->name.str(ctx) + "$FCO");
- connect_port(ctx, new_carry.get(), feedin.get(), id_FCO);
+ new_carry->name = ctx->id(feedin->name.str(ctx) + "$COUT");
+ connect_port(ctx, new_carry.get(), feedin.get(), ctx->id("COUT"));
connect_port(ctx, new_carry.get(), chain_in.cell, chain_in.port);
CellInfo *feedin_ptr = feedin.get();
@@ -343,24 +363,23 @@ class Ecp5Packer
}
// Create a feed out and loop through from the carry chain
- CellInfo *make_carry_feed_out(NetInfo *carry, boost::optional<PortRef> chain_next)
+ CellInfo *make_carry_feed_out(NetInfo *carry, boost::optional<PortRef> chain_next = boost::optional<PortRef>())
{
- std::unique_ptr<CellInfo> feedout = create_ecp5_cell(ctx, ctx->id("TRELLIS_SLICE"));
- feedout->params[ctx->id("MODE")] = "CCU2";
- feedout->params[ctx->id("LUT0_INITVAL")] = "0";
- feedout->params[ctx->id("LUT1_INITVAL")] = "10"; // LUT4 = 0; LUT2 = A
+ std::unique_ptr<CellInfo> feedout = create_ecp5_cell(ctx, ctx->id("CCU2C"));
+ feedout->params[ctx->id("INIT0")] = "0";
+ feedout->params[ctx->id("INIT1")] = "10"; // LUT4 = 0; LUT2 = A
feedout->params[ctx->id("INJECT1_0")] = "YES";
feedout->params[ctx->id("INJECT1_1")] = "NO";
PortRef carry_drv = carry->driver;
carry->driver.cell = nullptr;
- connect_port(ctx, carry, feedout.get(), id_F0);
+ connect_port(ctx, carry, feedout.get(), ctx->id("S0"));
std::unique_ptr<NetInfo> new_cin(new NetInfo());
- new_cin->name = ctx->id(feedout->name.str(ctx) + "$FCI");
+ new_cin->name = ctx->id(feedout->name.str(ctx) + "$CIN");
new_cin->driver = carry_drv;
carry_drv.cell->ports.at(carry_drv.port).net = new_cin.get();
- connect_port(ctx, new_cin.get(), feedout.get(), id_FCI);
+ connect_port(ctx, new_cin.get(), feedout.get(), ctx->id("CIN"));
if (chain_next) {
// Loop back into LUT4_1 for feedthrough
@@ -373,7 +392,8 @@ class Ecp5Packer
carry->users.end());
std::unique_ptr<NetInfo> new_cout(new NetInfo());
- new_cout->name = ctx->id(feedout->name.str(ctx) + "$FCO");
+ new_cout->name = ctx->id(feedout->name.str(ctx) + "$COUT");
+ connect_port(ctx, new_cout.get(), feedout.get(), ctx->id("COUT"));
chain_next->cell->ports[chain_next->port].net = nullptr;
connect_port(ctx, new_cout.get(), chain_next->cell, chain_next->port);
@@ -391,8 +411,68 @@ class Ecp5Packer
return feedout_ptr;
}
+ // Split a carry chain into multiple legal chains
+ std::vector<CellChain> split_carry_chain(CellChain &carryc)
+ {
+ bool start_of_chain = true;
+ std::vector<CellChain> chains;
+ const int max_length = (ctx->chip_info->width - 4) * 4 - 2;
+ auto curr_cell = carryc.cells.begin();
+ while (curr_cell != carryc.cells.end()) {
+ CellInfo *cell = *curr_cell;
+ if (start_of_chain) {
+ chains.emplace_back();
+ start_of_chain = false;
+ if (cell->ports.at(ctx->id("CIN")).net) {
+ // CIN is not constant and not part of a chain. Must feed in from fabric
+ PortRef inport;
+ inport.cell = cell;
+ inport.port = ctx->id("CIN");
+ CellInfo *feedin = make_carry_feed_in(cell->ports.at(ctx->id("CIN")).net, inport);
+ chains.back().cells.push_back(feedin);
+ }
+ }
+ chains.back().cells.push_back(cell);
+ bool split_chain = int(chains.back().cells.size()) > max_length;
+ if (split_chain) {
+ CellInfo *passout = make_carry_feed_out(cell->ports.at(ctx->id("COUT")).net);
+ chains.back().cells.back() = passout;
+ start_of_chain = true;
+ } else {
+ NetInfo *carry_net = cell->ports.at(ctx->id("COUT")).net;
+ bool at_end = (curr_cell == carryc.cells.end() - 1);
+ if (carry_net != nullptr && (carry_net->users.size() > 1 || at_end)) {
+ boost::optional<PortRef> nextport;
+ if (!at_end) {
+ auto next_cell = *(curr_cell + 1);
+ PortRef nextpr;
+ nextpr.cell = next_cell;
+ nextpr.port = ctx->id("CIN");
+ nextport = nextpr;
+ }
+ CellInfo *passout = make_carry_feed_out(cell->ports.at(ctx->id("COUT")).net, nextport);
+ chains.back().cells.push_back(passout);
+ }
+ ++curr_cell;
+ }
+ }
+ return chains;
+ }
+
+
// Pack carries and set up appropriate relative constraints
- void pack_carries() { log_info("Packing carries...\n"); }
+ void pack_carries() {
+ log_info("Packing carries...\n");
+ auto chains = find_chains(ctx, [](const Context *ctx, const CellInfo *cell) {
+ return is_carry(ctx, cell);
+ }, [](const Context *ctx, const CellInfo *cell) {
+ return net_driven_by(ctx, cell->ports.at(ctx->id("CIN")).net, is_carry, ctx->id("COUT"));
+ }, [](const Context *ctx, const CellInfo *cell) {
+ return net_only_drives(ctx, cell->ports.at(ctx->id("COUT")).net, is_carry,
+ ctx->id("CIN"), false);
+ }, 1);
+
+ }
// Pack LUTs that have been paired together
void pack_lut_pairs()
generated by cgit v1.2.3 (git 2.25.1) at 2025-04-26 15:33:52 +0000