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-rw-r--r--ice40/carry_tests/counter.v4
-rw-r--r--ice40/main.cc2
-rw-r--r--ice40/pack.cc21
-rw-r--r--ice40/place_legaliser.cc52
4 files changed, 63 insertions, 16 deletions
diff --git a/ice40/carry_tests/counter.v b/ice40/carry_tests/counter.v
index 8906ff45..1379a330 100644
--- a/ice40/carry_tests/counter.v
+++ b/ice40/carry_tests/counter.v
@@ -1,9 +1,9 @@
module top(input clk, cen, rst, ina, inb, output outa, outb, outc, outd);
- reg [3:0] ctr = 0;
+ reg [15:0] ctr = 0;
always @(posedge clk)
ctr <= ctr + 1'b1;
- assign {outa, outb, outc, outd} = ctr;
+ assign {outa, outb, outc, outd} = ctr[15:12];
endmodule
diff --git a/ice40/main.cc b/ice40/main.cc
index 7f913bb3..4fd16099 100644
--- a/ice40/main.cc
+++ b/ice40/main.cc
@@ -41,11 +41,11 @@
#include "nextpnr.h"
#include "pack.h"
#include "pcf.h"
+#include "place_legaliser.h"
#include "place_sa.h"
#include "route.h"
#include "timing.h"
#include "version.h"
-#include "place_legaliser.h"
USING_NEXTPNR_NAMESPACE
diff --git a/ice40/pack.cc b/ice40/pack.cc
index 0d48d58c..6e4eade1 100644
--- a/ice40/pack.cc
+++ b/ice40/pack.cc
@@ -178,12 +178,27 @@ static void pack_carries(Context *ctx)
std::unique_ptr<CellInfo> created_lc =
create_ice_cell(ctx, ctx->id("ICESTORM_LC"), cell.first.str(ctx) + "$CARRY");
carry_lc = created_lc.get();
+ created_lc->ports.at(ctx->id("I1")).net = i0_net;
+ if (i0_net) {
+ PortRef pr;
+ pr.cell = created_lc.get();
+ pr.port = ctx->id("I1");
+ i0_net->users.push_back(pr);
+ }
+ created_lc->ports.at(ctx->id("I2")).net = i1_net;
+ if (i1_net) {
+ PortRef pr;
+ pr.cell = created_lc.get();
+ pr.port = ctx->id("I2");
+ i1_net->users.push_back(pr);
+ }
new_cells.push_back(std::move(created_lc));
+
} else {
carry_lc = ctx->cells.at(*carry_lcs.begin()).get();
}
}
- carry_lc->attrs[ctx->id("CARRY_ENABLE")] = "1";
+ carry_lc->params[ctx->id("CARRY_ENABLE")] = "1";
replace_port(ci, ctx->id("CI"), carry_lc, ctx->id("CIN"));
replace_port(ci, ctx->id("CO"), carry_lc, ctx->id("COUT"));
if (i0_net) {
@@ -203,8 +218,8 @@ static void pack_carries(Context *ctx)
if (carry_lc->ports.at(ctx->id("CIN")).net != nullptr) {
IdString cin_net = carry_lc->ports.at(ctx->id("CIN")).net->name;
if (cin_net == ctx->id("$PACKER_GND_NET") || cin_net == ctx->id("$PACKER_VCC_NET")) {
- carry_lc->attrs[ctx->id("CIN_CONST")] = "1";
- carry_lc->attrs[ctx->id("CIN_SET")] = cin_net == ctx->id("$PACKER_VCC_NET") ? "1" : "0";
+ carry_lc->params[ctx->id("CIN_CONST")] = "1";
+ carry_lc->params[ctx->id("CIN_SET")] = cin_net == ctx->id("$PACKER_VCC_NET") ? "1" : "0";
carry_lc->ports.at(ctx->id("CIN")).net = nullptr;
auto cin_users = ctx->nets.at(cin_net)->users;
cin_users.erase(
diff --git a/ice40/place_legaliser.cc b/ice40/place_legaliser.cc
index 8f5680bf..c783dd0f 100644
--- a/ice40/place_legaliser.cc
+++ b/ice40/place_legaliser.cc
@@ -129,15 +129,36 @@ class PlacementLegaliser
std::vector<CellChain> 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"));
+ CellInfo *carry_prev =
+ net_driven_by(ctx, cell->ports.at(ctx->id("CIN")).net, is_lc, ctx->id("COUT"));
+ if (carry_prev != nullptr)
+ return carry_prev;
+ CellInfo *i3_prev = net_driven_by(ctx, cell->ports.at(ctx->id("I3")).net, is_lc, ctx->id("COUT"));
+ if (i3_prev != nullptr)
+ return i3_prev;
+ return (CellInfo *)nullptr;
},
[](const Context *ctx, const CellInfo *cell) {
- return net_only_drives(ctx, cell->ports.at(ctx->id("COUT")).net, is_lc, ctx->id("CIN"), false);
+ CellInfo *carry_next =
+ net_only_drives(ctx, cell->ports.at(ctx->id("COUT")).net, is_lc, ctx->id("CIN"), false);
+ if (carry_next != nullptr)
+ return carry_next;
+ CellInfo *i3_next =
+ net_only_drives(ctx, cell->ports.at(ctx->id("COUT")).net, is_lc, ctx->id("I3"), false);
+ if (i3_next != nullptr)
+ return i3_next;
+ return (CellInfo *)nullptr;
});
bool success = true;
// Find midpoints for all chains, before we start tearing them up
std::vector<CellChain> all_chains;
for (auto &base_chain : carry_chains) {
+ if (ctx->verbose) {
+ log_info("Found carry chain: \n");
+ for (auto entry : base_chain.cells)
+ log_info(" %s\n", entry->name.c_str(ctx));
+ log_info("\n");
+ }
std::vector<CellChain> split_chains = split_carry_chain(base_chain);
for (auto &chain : split_chains) {
get_chain_midpoint(ctx, chain, chain.mid_x, chain.mid_y);
@@ -146,6 +167,8 @@ class PlacementLegaliser
}
// Actual chain placement
for (auto &chain : all_chains) {
+ if (ctx->verbose)
+ log_info("Placing carry chain starting at '%s'\n", chain.cells.front()->name.c_str(ctx));
float base_x = chain.mid_x, base_y = chain.mid_y - (chain.cells.size() / 16.0f);
// Find Bel meeting requirements closest to the target base, returning location as <x, y, z>
auto chain_origin_bel = find_closest_bel(base_x, base_y, int(chain.cells.size()));
@@ -166,6 +189,9 @@ class PlacementLegaliser
for (int i = 0; i < int(chain.cells.size()); i++) {
int target_z = place_y * 8 + place_z + i;
place_lc(chain.cells.at(i), place_x, target_z / 8, target_z % 8);
+ if (ctx->verbose)
+ log_info(" Cell '%s' placed at (%d, %d, %d)\n", chain.cells.at(i)->name.c_str(ctx), place_x,
+ target_z / 8, target_z % 8);
}
}
return success;
@@ -234,9 +260,13 @@ class PlacementLegaliser
} else {
NetInfo *carry_net = cell->ports.at(ctx->id("COUT")).net;
if (carry_net != nullptr && carry_net->users.size() > 1) {
- CellInfo *passout = make_carry_pass_out(cell->ports.at(ctx->id("COUT")));
- chains.back().cells.push_back(passout);
- tile.push_back(passout);
+ if (carry_net->users.size() > 2 ||
+ (net_only_drives(ctx, carry_net, is_lc, ctx->id("I3"), false) !=
+ net_only_drives(ctx, carry_net, is_lc, ctx->id("CIN"), false))) {
+ CellInfo *passout = make_carry_pass_out(cell->ports.at(ctx->id("COUT")));
+ chains.back().cells.push_back(passout);
+ tile.push_back(passout);
+ }
}
++curr_cell;
}
@@ -257,8 +287,12 @@ class PlacementLegaliser
rippedCells.insert(existing);
ctx->unbindBel(bel);
}
+ if (cell->bel != BelId()) {
+ ctx->unbindBel(cell->bel);
+ }
ctx->bindBel(bel, cell->name, STRENGTH_LOCKED);
- loc.second = true; // Bel is now unavailable for further use
+ rippedCells.erase(cell->name); // If cell was ripped up previously, no need to re-place
+ loc.second = true; // Bel is now unavailable for further use
}
// Insert a logic cell to legalise a COUT->fabric connection
@@ -324,12 +358,10 @@ class PlacementLegaliser
bool placed = place_single_cell(ci);
if (!placed) {
if (ctx->force) {
- log_warning("failed to place cell '%s' of type '%s'\n", cell.c_str(ctx),
- ci->type.c_str(ctx));
+ log_warning("failed to place cell '%s' of type '%s'\n", cell.c_str(ctx), ci->type.c_str(ctx));
success = false;
} else {
- log_error("failed to place cell '%s' of type '%s'\n", cell.c_str(ctx),
- ci->type.c_str(ctx));
+ log_error("failed to place cell '%s' of type '%s'\n", cell.c_str(ctx), ci->type.c_str(ctx));
}
}
}
generated by cgit v1.2.3 (git 2.25.1) at 2024-07-02 17:20:49 +0000