Add arch API function for pip inversion

Author: Ravenslofty

common/kernel/arch_api.h

@@ -102,6 +102,7 @@ template <typename R> struct ArchAPI : BaseCtx
     virtual WireId getPipDstWire(PipId pip) const = 0;
     virtual DelayQuad getPipDelay(PipId pip) const = 0;
     virtual Loc getPipLocation(PipId pip) const = 0;
+    virtual bool isPipInverting(PipId pip) const = 0;
     // Group methods
     virtual GroupId getGroupByName(IdStringList name) const = 0;
     virtual IdStringList getGroupName(GroupId group) const = 0;

common/kernel/base_arch.h

@@ -288,6 +288,7 @@ template <typename R> struct BaseArch : ArchAPI<R>
     }
     virtual WireId getConflictingPipWire(PipId /*pip*/) const override { return WireId(); }
     virtual NetInfo *getConflictingPipNet(PipId pip) const override { return getBoundPipNet(pip); }
+    virtual bool isPipInverting(PipId /*pip*/) const override { return false; }
 
     // Group methods
     virtual GroupId getGroupByName(IdStringList /*name*/) const override { return GroupId(); };

docs/archapi.md

@@ -417,6 +417,12 @@ pip is already bound to that net.
 
 *BaseArch default: returns `getBoundPipNet(pip) == nullptr || getBoundPipNet(pip) == net`*
 
+### bool isPipInverting(PipId pip) const
+
+Returns true if the given pip inverts the net passing through it.
+
+*BaseArch default: returns `false`*
+
 ### NetInfo \*getBoundPipNet(PipId pip) const
 
 Return the net this pip is bound to.

himbaechel/arch.cc

@@ -285,13 +285,19 @@ IdStringList Arch::getWireName(WireId wire) const
 
 PipId Arch::getPipByName(IdStringList name) const
 {
-    NPNR_ASSERT(name.size() == 3);
+    NPNR_ASSERT(name.size() == 3 || (name.size() == 4 && name[4] == getCtx()->id("INV")));
     int tile = tile_name2idx.at(name[0]);
     const auto &tdata = chip_tile_info(chip_info, tile);
     for (int pip = 0; pip < tdata.pips.ssize(); pip++) {
         if (IdString(tdata.wires[tdata.pips[pip].dst_wire].name) == name[1] &&
-            IdString(tdata.wires[tdata.pips[pip].src_wire].name) == name[2])
-            return PipId(tile, pip);
+            IdString(tdata.wires[tdata.pips[pip].src_wire].name) == name[2]) {
+
+            auto tmp_pip = PipId(tile, pip);
+            if ((name.size() == 3 && !getCtx()->isPipInverting(tmp_pip)) ||
+                (name.size() == 4 && getCtx()->isPipInverting(tmp_pip))) {
+                return tmp_pip;
+            }
+        }
     }
     return PipId();
 }
@@ -300,6 +306,13 @@ IdStringList Arch::getPipName(PipId pip) const
 {
     auto &tdata = chip_tile_info(chip_info, pip.tile);
     auto &pdata = tdata.pips[pip.index];
+    if (getCtx()->isPipInverting(pip)) {
+        // TODO: variadic IdStringList::concat? this is messy.
+        return IdStringList::concat(tile_name.at(pip.tile),
+                            IdStringList::concat(IdString(tdata.wires[pdata.dst_wire].name),
+                                                    IdStringList::concat(IdString(tdata.wires[pdata.src_wire].name),
+                                                        getCtx()->id("INV"))));
+    }
     return IdStringList::concat(tile_name.at(pip.tile),
                                 IdStringList::concat(IdString(tdata.wires[pdata.dst_wire].name),
                                                      IdString(tdata.wires[pdata.src_wire].name)));

himbaechel/arch.h

@@ -662,6 +662,9 @@ struct Arch : BaseArch<ArchRanges>
         uarch->notifyPipChange(pip, nullptr);
         BaseArch::unbindPip(pip);
     }
+    bool isPipInverting(PipId pip) const override {
+        return uarch->isPipInverting(pip);
+    }
 
     // -------------------------------------------------
 

himbaechel/himbaechel_api.h

@@ -89,6 +89,7 @@ struct HimbaechelAPI
     virtual bool checkWireAvail(WireId wire) const { return true; }
     virtual bool checkPipAvail(PipId pip) const { return true; }
     virtual bool checkPipAvailForNet(PipId pip, const NetInfo *net) const { return checkPipAvail(pip); };
+    virtual bool isPipInverting(PipId pip) const { return false; }
 
     // --- Route lookahead ---
     virtual delay_t estimateDelay(WireId src, WireId dst) const;