1 files changed, 68 insertions, 10 deletions

diff --git a/common/timing.cc b/common/timing.cc
index d91dea20..814b0426 100644
--- a/common/timing.cc
+++ b/common/timing.cc
@@ -22,13 +22,16 @@
 #include <unordered_map>
 #include <utility>
 #include "log.h"
+#include "util.h"
 
 NEXTPNR_NAMESPACE_BEGIN
 
-static delay_t follow_net(Context *ctx, NetInfo *net, int path_length, delay_t slack);
+typedef std::unordered_map<const PortInfo*, delay_t> UpdateMap;
+
+static delay_t follow_net(Context *ctx, NetInfo *net, int path_length, delay_t slack, UpdateMap &updates);
 
 // Follow a path, returning budget to annotate
-static delay_t follow_user_port(Context *ctx, PortRef &user, int path_length, delay_t slack)
+static delay_t follow_user_port(Context *ctx, PortRef &user, int path_length, delay_t slack, UpdateMap &updates)
 {
     delay_t value;
     if (ctx->getPortClock(user.cell, user.port) != IdString()) {
@@ -47,7 +50,7 @@ static delay_t follow_user_port(Context *ctx, PortRef &user, int path_length, de
                 if (is_path) {
                     NetInfo *net = port.second.net;
                     if (net) {
-                        delay_t path_budget = follow_net(ctx, net, path_length, slack - comb_delay);
+                        delay_t path_budget = follow_net(ctx, net, path_length, slack - comb_delay, updates);
                         value = std::min(value, path_budget);
                     }
                 }
@@ -55,23 +58,26 @@ static delay_t follow_user_port(Context *ctx, PortRef &user, int path_length, de
         }
     }
 
-    if (value < user.budget) {
-        user.budget = value;
+    auto ret = updates.emplace(&user.cell->ports.at(user.port), value);
+    if (!ret.second && value < ret.first->second) {
+        ret.first->second = value;
     }
     return value;
 }
 
-static delay_t follow_net(Context *ctx, NetInfo *net, int path_length, delay_t slack)
+static delay_t follow_net(Context *ctx, NetInfo *net, int path_length, delay_t slack, UpdateMap &updates)
 {
     delay_t net_budget = slack / (path_length + 1);
     for (auto &usr : net->users) {
-        net_budget = std::min(net_budget, follow_user_port(ctx, usr, path_length + 1, slack));
+        net_budget = std::min(net_budget, follow_user_port(ctx, usr, path_length + 1, slack, updates));
     }
     return net_budget;
 }
 
 void assign_budget(Context *ctx)
 {
+    UpdateMap updates;
+
     log_break();
     log_info("Annotating ports with timing budgets\n");
     // Clear delays to a very high value first
@@ -92,15 +98,23 @@ void assign_budget(Context *ctx)
                     if (ctx->getCellDelay(cell.second.get(), clock_domain, port.first, clkToQ))
                         slack -= clkToQ;
                     if (port.second.net)
-                        follow_net(ctx, port.second.net, 0, slack);
+                        follow_net(ctx, port.second.net, 0, slack, updates);
                 }
             }
         }
     }
 
-    // Post-allocation check
+    // Update the budgets
     for (auto &net : ctx->nets) {
-        for (auto user : net.second->users) {
+        for (size_t i = 0; i < net.second->users.size(); ++i) {
+            auto& user = net.second->users[i];
+            auto pi = &user.cell->ports.at(user.port);
+            auto it = updates.find(pi);
+            if (it == updates.end()) continue;
+            auto budget = ctx->getNetinfoRouteDelay(net.second.get(), i) + it->second;
+            user.budget = ctx->getBudgetOverride(net.second->driver, budget);
+
+            // Post-update check
             if (user.budget < 0)
                 log_warning("port %s.%s, connected to net '%s', has negative "
                             "timing budget of %fns\n",
@@ -117,4 +131,48 @@ void assign_budget(Context *ctx)
     log_info("Checksum: 0x%08x\n", ctx->checksum());
 }
 
+void update_budget(Context *ctx)
+{
+    UpdateMap updates;
+
+    // Go through all clocked drivers and distribute the available path slack evenly into every budget
+    for (auto &cell : ctx->cells) {
+        for (auto& port : cell.second->ports) {
+            if (port.second.type == PORT_OUT) {
+                IdString clock_domain = ctx->getPortClock(cell.second.get(), port.first);
+                if (clock_domain != IdString()) {
+                    if (port.second.net)
+                        follow_net(ctx, port.second.net, 0, delay_t(1.0e12 / ctx->target_freq), updates);
+                }
+            }
+        }
+    }
+
+    // Update the budgets
+    for (auto &net : ctx->nets) {
+        for (size_t i = 0; i < net.second->users.size(); ++i) {
+            auto& user = net.second->users[i];
+            auto pi = &user.cell->ports.at(user.port);
+            auto it = updates.find(pi);
+            if (it == updates.end()) continue;
+            auto budget = ctx->getNetinfoRouteDelay(net.second.get(), i) + it->second;
+            user.budget = ctx->getBudgetOverride(net.second->driver, budget);
+
+            // Post-update check
+            if (ctx->verbose) {
+                if (user.budget < 0)
+                    log_warning("port %s.%s, connected to net '%s', has negative "
+                                "timing budget of %fns\n",
+                                user.cell->name.c_str(ctx), user.port.c_str(ctx), net.first.c_str(ctx),
+                                ctx->getDelayNS(user.budget));
+                else
+                    log_info("port %s.%s, connected to net '%s', has "
+                             "timing budget of %fns\n",
+                             user.cell->name.c_str(ctx), user.port.c_str(ctx), net.first.c_str(ctx),
+                             ctx->getDelayNS(user.budget));
+            }
+        }
+    }
+}
+
 NEXTPNR_NAMESPACE_END