2 files changed, 21 insertions, 16 deletions
diff --git a/ice40/arch.cc b/ice40/arch.cc
index e15abdd1..bdfb13fe 100644
--- a/ice40/arch.cc
+++ b/ice40/arch.cc
@@ -613,27 +613,31 @@ delay_t Arch::estimateDelay(WireId src, WireId dst) const
     int xd = x2 - x1, yd = y2 - y1;
     int xscale = 120, yscale = 120, offset = 0;
 
+    return xscale * abs(xd) + yscale * abs(yd) + offset;
+}
+
+delay_t Arch::predictDelay(const NetInfo *net_info, const PortRef &sink) const
+{
+    const auto& driver = net_info->driver;
+    auto driver_loc = getBelLocation(driver.cell->bel);
+    auto sink_loc = getBelLocation(sink.cell->bel);
+
+    if (driver.port == id_cout) {
+        if (driver_loc.y == sink_loc.y)
+            return 0;
+        return 250;
+    }
+
+    int xd = sink_loc.x - driver_loc.x, yd = sink_loc.y - driver_loc.y;
+    int xscale = 120, yscale = 120, offset = 0;
+
     // if (chip_info->wire_data[src.index].type == WIRE_TYPE_SP4_VERT) {
     //     yd = yd < -4 ? yd + 4 : (yd < 0 ? 0 : yd);
     //     offset = 500;
     // }
 
-    // Estimate for output mux
-    for (const auto &bp : getWireBelPins(src)) {
-        if (bp.pin == PIN_O && getBelType(bp.bel) == TYPE_ICESTORM_LC) {
-            offset += 330;
-            break;
-        }
-    }
-
-    // Estimate for input mux
-    for (const auto &bp : getWireBelPins(dst)) {
-        if ((bp.pin == PIN_I0 || bp.pin == PIN_I1 || bp.pin == PIN_I2 || bp.pin == PIN_I3) &&
-            getBelType(bp.bel) == TYPE_ICESTORM_LC) {
-            offset += 260;
-            break;
-        }
-    }
+    if (driver.port == id_o) offset += 330;
+    if (sink.port == id_i0 || sink.port == id_i1 || sink.port == id_i2 || sink.port == id_i3) offset += 260;
 
     return xscale * abs(xd) + yscale * abs(yd) + offset;
 }
diff --git a/ice40/arch.h b/ice40/arch.h
index f81fd21d..92698b4d 100644
--- a/ice40/arch.h
+++ b/ice40/arch.h
@@ -697,6 +697,7 @@ struct Arch : BaseCtx
     // -------------------------------------------------
 
     delay_t estimateDelay(WireId src, WireId dst) const;
+    delay_t predictDelay(const NetInfo *net_info, const PortRef &sink) const;
     delay_t getDelayEpsilon() const { return 20; }
     delay_t getRipupDelayPenalty() const { return 200; }
     float getDelayNS(delay_t v) const { return v * 0.001; }