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ecp5: Separate global promotion and routing

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Signed-off-by: David Shah <dave@ds0.me>
This commit is contained in:
David Shah 2018-10-31 16:22:34 +00:00
parent c782f07b1b
commit 24a2feda30
4 changed files with 86 additions and 32 deletions
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2
ecp5/arch.h
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@ -491,7 +491,7 @@ struct Arch : BaseCtx
BelId getBelByLocation(Loc loc) const;
BelRange getBelsByTile(int x, int y) const;
bool getBelGlobalBuf(BelId bel) const { return false; }
bool getBelGlobalBuf(BelId bel) const { return getBelType(bel) == id_DCCA; }
bool checkBelAvail(BelId bel) const
{

113
ecp5/globals.cc
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@ -25,6 +25,7 @@
#include "log.h"
#include "nextpnr.h"
#include "place_common.h"
#include "util.h"
#define fmt_str(x) (static_cast<const std::ostringstream &>(std::ostringstream() << x).str())
NEXTPNR_NAMESPACE_BEGIN
@ -257,6 +258,45 @@ class Ecp5GlobalRouter
return true;
}
// Get DCC wirelength based on source
wirelen_t get_dcc_wirelen(CellInfo *dcc)
{
NetInfo *clki = dcc->ports.at(id_CLKI).net;
BelId drv_bel;
const PortRef &drv = clki->driver;
if (drv.cell == nullptr) {
return 0;
} else if (drv.cell->attrs.count(ctx->id("BEL"))) {
drv_bel = ctx->getBelByName(ctx->id(drv.cell->attrs.at(ctx->id("BEL"))));
} else {
// Check if driver is a singleton
BelId last_bel;
bool singleton = true;
for (auto bel : ctx->getBels()) {
if (ctx->getBelType(bel) == drv.cell->type) {
if (last_bel != BelId()) {
singleton = false;
break;
}
last_bel = bel;
}
}
if (singleton && last_bel != BelId()) {
drv_bel = last_bel;
}
}
if (drv_bel == BelId()) {
// Driver is not locked. Use standard metric
float tns;
return get_net_metric(ctx, clki, MetricType::WIRELENGTH, tns);
} else {
// Driver is locked
Loc dcc_loc = ctx->getBelLocation(dcc->bel);
Loc drv_loc = ctx->getBelLocation(drv_bel);
return std::abs(dcc_loc.x - drv_loc.x) + std::abs(dcc_loc.y - drv_loc.y);
}
}
// Attempt to place a DCC
void place_dcc(CellInfo *dcc)
{
@ -266,8 +306,7 @@ class Ecp5GlobalRouter
if (ctx->getBelType(bel) == id_DCCA && ctx->checkBelAvail(bel)) {
if (ctx->isValidBelForCell(dcc, bel)) {
ctx->bindBel(bel, dcc, STRENGTH_LOCKED);
float tns;
wirelen_t wirelen = get_net_metric(ctx, dcc->ports.at(id_CLKI).net, MetricType::WIRELENGTH, tns);
wirelen_t wirelen = get_dcc_wirelen(dcc);
if (wirelen < best_wirelen) {
best_bel = bel;
best_wirelen = wirelen;
@ -322,47 +361,59 @@ class Ecp5GlobalRouter
Context *ctx;
public:
void promote_and_route_globals()
void promote_globals()
{
log_info("Promoting and routing globals...\n");
log_info("Promoting globals...\n");
auto clocks = get_clocks();
for (auto clock : clocks) {
log_info(" promoting clock net %s to global network\n", clock->name.c_str(ctx));
insert_dcc(clock);
}
}
void route_globals()
{
log_info("Routing globals...\n");
std::set<int> all_globals, fab_globals;
for (int i = 0; i < 16; i++) {
all_globals.insert(i);
if (i < 8)
fab_globals.insert(i);
}
for (auto clock : clocks) {
bool drives_fabric = std::any_of(clock->users.begin(), clock->users.end(),
[this](const PortRef &port) { return !is_clock_port(port); });
int glbid;
if (drives_fabric) {
if (fab_globals.empty())
continue;
glbid = *(fab_globals.begin());
} else {
glbid = *(all_globals.begin());
}
all_globals.erase(glbid);
fab_globals.erase(glbid);
log_info(" promoting clock net %s to global %d\n", clock->name.c_str(ctx), glbid);
auto old_users = clock->users;
NetInfo *global = insert_dcc(clock);
bool routed = route_onto_global(global, glbid);
NPNR_ASSERT(routed);
for (auto cell : sorted(ctx->cells)) {
CellInfo *ci = cell.second;
if (ci->type == id_DCCA) {
NetInfo *clock = ci->ports.at(id_CLKO).net;
NPNR_ASSERT(clock != nullptr);
bool drives_fabric = std::any_of(clock->users.begin(), clock->users.end(),
[this](const PortRef &port) { return !is_clock_port(port); });
// WCK must have routing priority
auto sorted_users = global->users;
std::sort(sorted_users.begin(), sorted_users.end(), [this](const PortRef &a, const PortRef &b) {
return global_route_priority(a) < global_route_priority(b);
});
for (const auto &user : sorted_users) {
route_logic_tile_global(global, glbid, user);
int glbid;
if (drives_fabric) {
if (fab_globals.empty())
continue;
glbid = *(fab_globals.begin());
} else {
glbid = *(all_globals.begin());
}
log_info(" routing clock net %s using global %d\n", clock->name.c_str(ctx), glbid);
bool routed = route_onto_global(clock, glbid);
NPNR_ASSERT(routed);
// WCK must have routing priority
auto sorted_users = clock->users;
std::sort(sorted_users.begin(), sorted_users.end(), [this](const PortRef &a, const PortRef &b) {
return global_route_priority(a) < global_route_priority(b);
});
for (const auto &user : sorted_users) {
route_logic_tile_global(clock, glbid, user);
}
}
}
}
};
void route_ecp5_globals(Context *ctx) { Ecp5GlobalRouter(ctx).promote_and_route_globals(); }
void promote_ecp5_globals(Context *ctx) { Ecp5GlobalRouter(ctx).promote_globals(); }
void route_ecp5_globals(Context *ctx) { Ecp5GlobalRouter(ctx).route_globals(); }
NEXTPNR_NAMESPACE_END

1
ecp5/globals.h
View File

@ -21,6 +21,7 @@
NEXTPNR_NAMESPACE_BEGIN
void promote_ecp5_globals(Context *ctx);
void route_ecp5_globals(Context *ctx);
NEXTPNR_NAMESPACE_END

2
ecp5/pack.cc
View File

@ -24,6 +24,7 @@
#include "cells.h"
#include "chain_utils.h"
#include "design_utils.h"
#include "globals.h"
#include "log.h"
#include "util.h"
NEXTPNR_NAMESPACE_BEGIN
@ -1047,6 +1048,7 @@ class Ecp5Packer
pack_lut_pairs();
pack_remaining_luts();
pack_remaining_ffs();
promote_ecp5_globals(ctx);
ctx->check();
}