Fix handling of partial covers in muxcover, fixes #1132

Signed-off-by: Clifford Wolf <clifford@clifford.at>

diff --git a/passes/techmap/muxcover.cc b/passes/techmap/muxcover.cc
index b0722134e3bc867826757e56ad8cc7dec181f57b..c84cfc39a8821b6a60d175028a9a3551a106b4e9 100644 (file)
--- a/passes/techmap/muxcover.cc
+++ b/passes/techmap/muxcover.cc
@@ -81,6 +81,23 @@ struct MuxcoverWorker
                decode_mux_counter = 0;
        }
 
+       bool xcmp(std::initializer_list<SigBit> list)
+       {
+               auto cursor = list.begin(), end = list.end();
+               log_assert(cursor != end);
+               SigBit tmp = *(cursor++);
+               while (cursor != end) {
+                       SigBit bit = *(cursor++);
+                       if (bit == State::Sx)
+                               continue;
+                       if (tmp == State::Sx)
+                               tmp = bit;
+                       if (bit != tmp)
+                               return false;
+               }
+               return true;
+       }
+
        void treeify()
        {
                pool<SigBit> roots;
@@ -144,6 +161,8 @@ struct MuxcoverWorker
                        if (tree.muxes.count(bit) == 0) {
                                if (first_layer || nopartial)
                                        return false;
+                               while (path[0] && path[1])
+                                       path++;
                                if (path[0] == 'S')
                                        ret_bit = State::Sx;
                                else
@@ -280,7 +299,7 @@ struct MuxcoverWorker
                        ok = ok && follow_muxtree(S2, tree, bit, "BS");
 
                        if (nodecode)
-                               ok = ok && S1 == S2;
+                               ok = ok && xcmp({S1, S2});
 
                        ok = ok && follow_muxtree(T1, tree, bit, "S");
 
@@ -330,13 +349,13 @@ struct MuxcoverWorker
                        ok = ok && follow_muxtree(S4, tree, bit, "BBS");
 
                        if (nodecode)
-                               ok = ok && S1 == S2 && S2 == S3 && S3 == S4;
+                               ok = ok && xcmp({S1, S2, S3, S4});
 
                        ok = ok && follow_muxtree(T1, tree, bit, "AS");
                        ok = ok && follow_muxtree(T2, tree, bit, "BS");
 
                        if (nodecode)
-                               ok = ok && T1 == T2;
+                               ok = ok && xcmp({T1, T2});
 
                        ok = ok && follow_muxtree(U1, tree, bit, "S");
 
@@ -407,7 +426,7 @@ struct MuxcoverWorker
                        ok = ok && follow_muxtree(S8, tree, bit, "BBBS");
 
                        if (nodecode)
-                               ok = ok && S1 == S2 && S2 == S3 && S3 == S4 && S4 == S5 && S5 == S6 && S6 == S7 && S7 == S8;
+                               ok = ok && xcmp({S1, S2, S3, S4, S5, S6, S7, S8});
 
                        ok = ok && follow_muxtree(T1, tree, bit, "AAS");
                        ok = ok && follow_muxtree(T2, tree, bit, "ABS");
@@ -415,13 +434,13 @@ struct MuxcoverWorker
                        ok = ok && follow_muxtree(T4, tree, bit, "BBS");
 
                        if (nodecode)
-                               ok = ok && T1 == T2 && T2 == T3 && T3 == T4;
+                               ok = ok && xcmp({T1, T2, T3, T4});
 
                        ok = ok && follow_muxtree(U1, tree, bit, "AS");
                        ok = ok && follow_muxtree(U2, tree, bit, "BS");
 
                        if (nodecode)
-                               ok = ok && U1 == U2;
+                               ok = ok && xcmp({U1, U2});
 
                        ok = ok && follow_muxtree(V1, tree, bit, "S");